Data protector, data protection seal and drawing device

文档序号：1821630 发布日期：2021-11-09 浏览：17次中文

阅读说明：本技术 数据保护器、数据保护封条及绘图装置 (Data protector, data protection seal and drawing device ) 是由石田武久于 2020-02-13 设计创作，主要内容包括：根据本公开内容实施例的数据保护器包括：数据层,被配置为将机密信息记录为可见图像；以及一个或多个覆盖层,设置在数据层的上方和/或下方,并且被配置为在可见波长范围中在显色状态与脱色状态之间转换。(A data protector according to an embodiment of the present disclosure includes: a data layer configured to record the confidential information as a visible image; and one or more cover layers disposed above and/or below the data layer and configured to switch between a colored state and a decolored state in a visible wavelength range.)

1. A data protector, comprising:

a data layer that records the confidential information as a visible image; and

one or more cover layers disposed above and/or below the data layer and switching between a colored state and a decolored state in a visible wavelength range.

2. The data protector of claim 1,

the data layer is switchable between the colored state and the bleached state in the visible wavelength range and contains a reversible material having a switching condition different from the switching condition of the one or more cover layers, and

the confidential information is recorded as a visible image on the data layer by the development of the reversible material.

3. The data protector of claim 1, wherein the one or more cover layers contain a leuco pigment.

4. The data protector of claim 1, wherein the one or more cover layers comprise a photochromic material.

5. The data protector of claim 1, wherein the one or more cover layers contain a material that controls light transmittance through phase change in the visible wavelength range or a material that switches between a colored state and a bleached state through phase change in the visible wavelength range.

6. The data protector of claim 1, wherein the one or more overlay layers contain a grayscale image of a pattern different from a pattern of the visible image.

7. The data protector of claim 1, further comprising one or more water vapor barrier layers protecting the one or more cover layers and having a thickness of 0.1g/m²Water vapor permeability below day.

8. The data protector of claim 1, further comprising one or more ultraviolet blocking layers that protect the one or more cover layers and have a light transmittance of 70% or less for light having a wavelength shorter than 420 nm.

9. The data protector of claim 1, wherein there is also a thermal insulating layer between the one or more cover layers and the data layer.

10. The data protector of claim 1, further comprising a substrate supporting the data layer, wherein,

the substrate is made of paper.

11. The data protector of claim 1, further comprising a substrate supporting the data layer, wherein,

the base material is made of synthetic resin.

12. A data protector, comprising:

a data layer on which confidential information is recorded as a visible image; and

one or more cover layers disposed above and/or below the data layer and switching between a colored state and a decolored state in a visible wavelength range.

13. The data protector of claim 12, wherein the data layer is a printed layer in which the confidential information is irreversibly secured to the substrate.

14. A data protection seal that protects a data layer that records confidential information as a visible image, the data protection seal comprising:

one or more cover layers that switch between a colored state and a bleached state in the visible wavelength range; and

an adhesive layer disposed at a position facing the one or more cover layers.

15. The data protective seal of claim 14, wherein the one or more cover layers comprise a reversible material having a switching condition different from a switching condition of the data layer.

16. The data protective seal of claim 14, further comprising a protective layer protecting the adhesive layer.

17. A data protection seal for protecting a data layer on which confidential information is recorded as a visible image, the data protection seal comprising:

one or more cover layers that switch between a colored state and a bleached state in the visible wavelength range; and

an adhesive layer disposed at a position facing the one or more cover layers.

18. The data protective seal of claim 17, further comprising a protective layer protecting the adhesive layer.

19. A drawing device that performs at least one of writing or erasing on a data layer and one or more cover layers of a data protector including the data layer and the one or more cover layers on which confidential information is recorded as a visible image, the data layer containing a first reversible material that switches between a colored state and a decolored state in a visible wavelength range, the one or more cover layers containing a second reversible material that switches between the colored state and the decolored state in the visible wavelength range and being disposed above and/or below the data layer, the drawing device comprising:

a light source unit that emits a laser beam, which is at least one of a first laser beam having a condition under which no color development and decoloration reaction of the first reversible material occurs and any reaction of the color development and decoloration reaction of the second reversible material occurs, or a second laser beam having a condition under which no color development and decoloration reaction of the second reversible material occurs and any reaction of the color development and decoloration reaction of the first reversible material occurs; and

an optical unit performing writing and/or erasing on the data layer or the one or more cover layers by irradiating the laser beam emitted from the light source unit to the data layer or the one or more cover layers.

20. The drawing device according to claim 19 wherein the light source unit emits a laser beam such that by irradiating the laser beam by the optical unit, the one or more cover layers have a reverse image of the visible image or an image different from the visible image.

Technical Field

The present disclosure relates to a data protector, a data protection seal, and a drawing device.

Background

In the case where important information such as a password and an encryption key is stored and stored on a recording medium connected to a computer for a long time, there is a problem that the stored information is stolen or becomes unreadable by a third party due to a hacking or a malfunction of a device. At present, the method of printing on paper and storing it is considered to be the safest. However, the risk of information leakage due to illegal viewing by a third party or the risk of print loss due to deterioration of paper or ink is not zero. The disclosure described in PTL1 below is known, for example, as a measure for suppressing illegal viewing by a third party.

List of citations

Patent document

PTL 1: japanese unexamined patent application publication No.2007-65266

Disclosure of Invention

However, in the disclosure described in PTL1, there is a problem that visualization cannot be achieved without using an infrared sensor. It is therefore desirable to provide a data protector and a data protection seal that can be visualized in the visible wavelength range. It is also desirable to provide a drawing device for making such data protectors and data protective seals visible or invisible.

A first data protector according to an embodiment of the present disclosure includes: a data layer configured to record the confidential information as a visible image; and one or more cover layers disposed above and/or below the data layer and configured to switch between a colored state and a bleached state in a visible wavelength range.

A second data protector according to an embodiment of the present disclosure includes: a data layer on which confidential information is recorded as a visible image; and one or more cover layers disposed above and/or below the data layer and configured to switch between a colored state and a decolored state in a visible wavelength range.

In the first and second data protectors according to the embodiments of the present disclosure, one or more cover layers configured to switch between a colored state and a decolored state in a visible wavelength range are provided above and/or below the data layer. This allows for hiding the confidential information, for example by turning one or more overlay layers into a colored state to turn the data layer into an invisible state, or by the overlay layers preventing identification of the confidential information. Further, by making the one or more cover layers to be in a decolored state to make the data layer to be in a visible state, the confidential information can be visually recognized in the visible wavelength range.

A first data protection seal according to an embodiment of the present disclosure is a seal that protects a data layer configured to record confidential information as a visible image. The data protection seal includes: one or more cover layers configured to control visibility and invisibility of the confidential information in a visible wavelength range; and an adhesive layer disposed at a position facing the one or more cover layers.

A second data protection seal according to an embodiment of the present disclosure is a seal that protects a data layer on which confidential information is recorded as a visible image. The data protection seal includes: one or more cover layers configured to control visibility and invisibility of the confidential information in a visible wavelength range; and an adhesive layer disposed at a position facing the one or more cover layers.

In the first and second data protection seals according to the embodiments of the present disclosure, for example, confidential information may be hidden by attaching the first and second data protection seals to the data layer and turning one or more cover layers into a colored state to turn the data layer into an invisible state, or by preventing identification of the confidential information by the cover layer. Further, by making the one or more cover layers to be in a decolored state to make the data layer to be in a visible state, the confidential information can be visually recognized in the visible wavelength range.

A drawing device according to an embodiment of the present disclosure is a device that performs writing and/or erasing on a data protector. Here, the data protector includes: a data layer on which confidential information is recorded as a visible image, the data layer containing a first reversible material configured to control color development and color removal in a visible wavelength range; and one or more cover layers comprising a second reversible material configured to control color development and decoloration in the visible wavelength range, and disposed above and/or below the data layer. The drawing device includes a light source unit and an optical unit. The light source unit emits a laser beam, which is at least one of the first laser beam or the second laser beam. The first laser beam has a condition under which neither the coloring and decoloring reactions of the first reversible material occur but either the coloring and decoloring reactions of the second reversible material occur. The second laser beam has a condition under which neither the coloring nor the decoloring reaction of the second reversible material occurs but either the coloring or the decoloring reaction of the first reversible material occurs. The optical unit performs writing and/or erasing on the data layer or the one or more cover layers by irradiating the data layer or the one or more cover layers with a laser beam emitted from the light source unit.

In the drawing device according to the embodiment of the present disclosure, writing and/or erasing on one or more cover layers is performed by irradiating the one or more cover layers with a laser beam emitted from a light source unit. This allows the confidential information to be hidden, for example, by making the data layer invisible by performing writing on the data protector with the drawing device to bring the overlay layer or layers into a colored state, or by preventing identification of the confidential information by the overlay layer or layers. Further, by performing erasing of the one or more cover layers with the drawing device, the one or more cover layers are changed to a decolored state to change the data layer to a visible state, thereby making it possible to visibly identify the confidential information in the visible wavelength range. Further, in the drawing device according to the embodiment of the present disclosure, writing and/or erasing is performed on the data layer by irradiating the data layer with the laser beam emitted from the light source unit. This allows the drawing device to write confidential information to the data layer by performing a write on the data protector. Further, the data layer may be erased by performing erasing on the data layer using the drawing device.

Drawings

Fig. 1 is a diagram showing a cross-sectional configuration example of a data protection seal according to a first embodiment of the present disclosure.

Fig. 2 is a diagram showing a state in which the data protection seal of fig. 1 is attached to a document.

Fig. 3 is a diagram showing a schematic configuration example of a drawing device that performs drawing on the data protection seal of fig. 1.

Fig. 4 is a diagram showing a schematic configuration example of the scanner unit of fig. 3.

Fig. 5 is a diagram showing an example of writing and erasing on a data protection seal using the drawing device of fig. 3.

Fig. 6 is a diagram showing a modification of the writing of fig. 5.

Fig. 7 is a diagram showing a modification of the writing of fig. 5.

Fig. 8 is a diagram showing a modification of the cross-sectional configuration of the data protection seal of fig. 1.

Fig. 9 is a diagram showing a modification of the schematic configuration of the scanner unit of fig. 4.

Fig. 10 is a diagram showing an example of writing on the data protection seal of fig. 8.

Fig. 11 is a diagram showing an example of erasing on the data protection seal of fig. 8.

Fig. 12 is a diagram showing a modification of the cross-sectional configuration of the document shown in fig. 2.

Fig. 13 is a diagram showing an example of writing on a data protection seal attached to the document shown in fig. 12.

Fig. 14 is a diagram showing an example of erasure on the data protection seal attached to the document shown in fig. 12.

Fig. 15 is a diagram showing a cross-sectional configuration example of a document according to a second embodiment of the present disclosure.

Fig. 16 is a diagram showing an example of writing on the document of fig. 15.

Fig. 17 is a diagram showing an example of erasing on the document of fig. 15.

Fig. 18 is a diagram showing a modification of the writing of fig. 16.

Fig. 19 is a diagram showing a modification of the writing of fig. 16.

Fig. 20 is a diagram showing a modification of the cross-sectional configuration of the document of fig. 15.

Fig. 21 is a diagram showing a modification of the schematic configuration of the scanner unit of fig. 4.

Fig. 22 is a diagram showing an example of writing on the document of fig. 20.

Fig. 23 is a diagram showing an example of erasing on the document of fig. 20.

Fig. 24 is a diagram showing a cross-sectional configuration example of a document on which writing is performed.

Fig. 25 is a diagram showing a plane configuration example of the document of fig. 24.

Fig. 26 is a diagram showing a modification of the planar configuration of the document on which writing is performed.

Fig. 27 is a diagram showing a modification of the cross-sectional configuration of the document of fig. 15.

Fig. 28 is a diagram showing a cross-sectional configuration example of a card according to a third embodiment of the present disclosure.

Fig. 29 is a diagram showing a modification of the cross-sectional configuration example of the card of fig. 28.

Fig. 30 is a diagram showing a modification of the cross-sectional configuration of the data protection seal of fig. 1.

Fig. 31 is a diagram showing a modification of the cross-sectional configuration of the data protection seal of fig. 1.

Fig. 32 is a diagram showing a modification of the cross-sectional configuration of the data protection seal of fig. 1.

Fig. 33 is a diagram showing a modification of the cross-sectional configuration of the document of fig. 15.

Fig. 34 is a diagram showing a modification of the cross-sectional configuration of the document of fig. 15.

Fig. 35 is a diagram showing a modification of the cross-sectional configuration of the document of fig. 15.

Fig. 36 is a diagram showing a modification of the cross-sectional configuration of the card of fig. 28.

Fig. 37 is a diagram showing a modification of the cross-sectional configuration of the card of fig. 28.

Fig. 38 is a diagram showing a modification of the cross-sectional configuration of the card of fig. 28.

Detailed Description

Some embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Note that the description is given in the following order.

1. First embodiment (FIGS. 1 to 5)

Examples of data-protecting seals provided with an overlay

2. Modification of the first embodiment

Modification A (FIGS. 6 and 7)

Example of writing reverse image data and Complex patterned image data on the cover layer

Modification B

Examples of the cover layer including photochromic materials

Modification example C

Examples of capping layers including phase change materials

Modification D (FIGS. 8 to 11)

Example of a data protection seal provided with two cover layers

Modification E (FIGS. 12 to 14)

Examples of data layer reversibility

3. Second embodiment (FIGS. 15 to 17)

Example of a document provided with an overlay

4. Modification of the second embodiment

Modification F (FIGS. 18 and 19)

Example of writing reverse image data and Complex patterned image data on the cover layer

Modification G

Examples of the cover layer including photochromic materials

Modification example H

Examples of capping layers including phase change materials

Modification I (FIGS. 20 to 23)

Example of a document provided with two overlays

Modification J (FIGS. 24 to 26)

Example of writing reverse image data and complex patterned image data on each of the plurality of cover layers in modification I

Modification K (FIG. 27)

Examples of data layer being irreversible

5. Third embodiment (FIG. 28)

Examples of cards provided with a cover layer

6. Modification of the third embodiment

Modification L (FIG. 29)

Examples of data layer being irreversible

7. Modifications common to embodiments

Modification M (FIGS. 30 to 32)

Example of a data protection seal provided with a water vapor barrier layer and an ultraviolet light barrier layer

Modification N (FIGS. 33 to 35)

The document is provided with an example of a water vapor barrier layer and an ultraviolet barrier layer.

Modification O (FIGS. 36 to 38)

Example of a card provided with a water vapor barrier layer and an ultraviolet barrier layer

[1. first embodiment ]

[ arrangement ]

A data protection seal 100 according to a first embodiment of the present disclosure will be described. Fig. 1 shows a schematic configuration example of a data protection seal 100 according to the present embodiment. The data protection seal 100 is a layer that protects a data layer 210 (described later), and confidential information is recorded as a visible image on the data layer 210. The data protective seal 100 includes, for example, a cover layer 110, an adhesive layer 120, and a protective layer 130. The capping layer 110, the adhesive layer 120, and the protective layer 130 are stacked in this order. The adhesive layer 120 and the protective layer 130 are disposed at positions opposite to the cover layer 110.

The protective layer 130 is a layer that protects the adhesive layer 120 and is peeled off from the adhesive layer 120 when the data protective seal 100 is used. The protective layer 130 is a resin layer having flexibility, and includes, for example, polyethylene terephthalate (PET) or the like. The adhesive layer 120 is a layer for attaching the data-protecting seal 100 to, for example, a document or the like, and contains, for example, an acrylic pressure-sensitive adhesive or the like.

The overlay layer 110 is a layer for hiding confidential information (hereinafter, simply referred to as "confidential information") recorded on a document or the like by being attached to the document or the like. The cover layer 110 is configured to switch between a colored state and a bleached state in the visible wavelength range. Preferably, the color of the cover layer 110 when developed is black having an optical density of 1.5 or more. It should be noted that the optical density of the color at the time of coloring of the cover layer 110 may be a density at which the visible image of the data layer 210 cannot be visually recognized. The visible image of the overlay layer 110 may include multiple colors or may include a single color.

When the cover layer 110 attached to a document or the like is in a colored state in a visible wavelength range, the cover layer 110 prevents confidential information from being visually recognized or recognized. In the case where the overlay layer 110 prevents the confidential information from being visibly identified, the overlay layer 110 leaves a portion or all of the confidential information in an invisible state. On the other hand, in the case where the cover layer 110 prevents the confidential information from being recognized, a part or all of the confidential information may be in a state of being visible through the cover layer 110, but the confidential information appears as a visible image different from the original visible image of the confidential information due to the cover layer 110.

Further, when the cover layer 110 attached to a document or the like is in a decolored state in visible wavelengths, the cover layer 110 does not prevent confidential information from being visually recognized. At this time, the confidential information is in a state of being visible through the cover layer 110.

The cover layer 110 includes, for example, a leuco pigment (reversible thermosensitive coloring composition) and a photothermal conversion agent for generating heat at the time of writing. The cover layer 110 also includes, for example, a developer and a polymer.

Fig. 2 shows a state in which the data protection seal 100 is attached to a document 200. In FIG. 2, the protective layer 130 has been peeled off the adhesive layer 120, and the cover layer 110 is attached to the data layer 210 of the document 200 through the adhesive layer 120. The document 200 includes a base layer 220 and a data layer 210 on which confidential information is recorded as a visible image. The base layer 220 includes an opaque material, such as paper. The data layer 210 is, for example, a printed layer in which confidential information is irreversibly fixed on the base layer 220, and includes a visible image formed, for example, by offset printing. It should be noted that the data layer 210 may be characters or pictures handwritten on the base layer 220. The data layer 210 includes visible images such as numbers, letters, bar codes, two-dimensional codes, photographs, and graphics.

Fig. 3 shows a schematic configuration example of the drawing apparatus 1 that performs writing and erasing on the cover layer 110 of the data protection seal 100.

The drawing device 1 includes, for example, a communication unit 10, an input unit 20, a display unit 30, a storage unit 40, an image recognition unit 50, a drawing unit 60, and an information processing unit 70. The drawing device 1 is coupled to a network through a communication unit 10. The network is, for example, a communication line such as a LAN or a WAN. The terminal device is coupled to a network. The drawing apparatus 1 is configured to be able to communicate with a terminal device via a network. The terminal device is, for example, a portable terminal, and is configured to be able to communicate with the drawing apparatus 1 via a network.

The communication unit 10 communicates with an external device such as a terminal device. The communication unit 10 outputs one or more pieces of input image data received from an external device such as a mobile terminal, for example, to the information processing unit 70. The information processing unit 70 stores one or more pieces of input image data input from the communication unit 10 in the storage unit 40. The one or more pieces of input image data are, for example, data in which gradation values of respective drawing coordinates are described.

The input unit 20 receives an input (e.g., an execution instruction) from a user. The input unit 20 outputs information input by the user to the information processing unit 70. The information processing unit 70 executes predetermined processing based on the information input from the input unit 20. The display unit 30 displays a screen based on pieces of screen data created by the information processing unit 70. The display unit 30 includes, for example, a liquid crystal panel or an organic EL (electroluminescence) panel.

The image recognizing unit 50 performs measurement in response to a measurement command from the information processing unit 70. The image recognition unit 50 acquires visible image data of the data layer 210, for example, by measuring the surface of the data layer 210. The visible image data is, for example, data in which gradation values of respective drawing coordinates are described. The image recognizing unit 50 outputs visible image data obtained by measuring the surface of the data layer 210 to the information processing unit 70. The information processing unit 70 stores the visible image data input from the image recognition unit 50 in the storage unit 40.

The storage unit 40 stores, for example, a program 41 and image data 42, the program 41 including a set of steps for performing writing and erasing on the cover layer 110 of the data-protecting seal 100. The image data 42 is, for example, data describing gradation values of respective drawing coordinates, and includes image data to be used when a writing operation is performed on the data protection seal 100 and image data to be used when erasing is performed on the data protection seal 100. The image data 42 may also be image data used in writing and erasing on the data protection seal 100. The information processing unit 70 performs writing or erasing on the cover layer 110 by loading the program 41. The storage unit 40 stores, for example, one or more pieces of input image data input from the communication unit 10, or visible image data input from the image recognition unit 50. When writing is performed on the cover layer 110, one or more pieces of input image data or visible image data may also be used.

The information processing unit 70 includes, for example, a CPU (central processing unit) and a GPU (graphics processing unit).

The information processing unit 70 executes, for example, the program 41 stored in the storage unit 40. Execution of the program 41 in the information processing unit 70 is described in detail later.

Next, the drawing unit 60 will be described. Fig. 4 shows a schematic configuration example of the drawing unit 60. The drawing unit 60 includes, for example, a signal processing circuit 61, a laser driving circuit 62, a light source unit 63, an adjustment mechanism 64, a scanner driving circuit 65, and a scanner unit 66. The drawing unit 60 performs writing or erasing on the cover layer 110 by controlling the output of the light source unit 63 based on the output set value input from the information processing unit 70. The output setting value is, for example, a command voltage value corresponding to a gradation value of each drawing coordinate of the image data 42, one or more pieces of input image data, or visible image data.

The signal processing circuit 61 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates, for example, a pixel signal Dout corresponding to a scanner operation of the scanner unit 66 from the image signal Din. The pixel signal Dout causes the light source unit 63 to output a laser beam having a power corresponding to an output set value. The signal processing circuit 61 controls the peak value of the current pulse to be applied to the light source unit 63 (light source 63A) in accordance with the signal Dout together with the laser driving circuit 62.

The laser drive circuit 62 drives the light source 63A of the light source unit 63, for example, in accordance with the pixel signal Dout. The laser drive circuit 62 controls the luminance (luminance) of a laser beam used for drawing an image in accordance with the pixel signal Dout, for example. The laser drive circuit 62 includes, for example, a drive circuit that drives the light source 63A. The light source 63A performs writing and erasing on the data seal 100 by outputting a laser beam of a power corresponding to the output set value to the data seal 100. The light source 63A emits a laser beam in the near infrared region. The light source 63A is, for example, a laser diode that emits a laser beam La having a wavelength λ 1.

The light source unit 63 includes, for example, a light source 63A and a lens 63 e. The adjustment mechanism 64 is a mechanism for adjusting the focus of the light (laser light La) emitted from the light source unit 63. The adjustment mechanism 64 is a mechanism for adjusting the position of the lens 63e by a manual operation of a user, for example. It should be noted that the adjustment mechanism 64 may be a mechanism for adjusting the position of the lens 63e by mechanical manipulation.

The scanner drive circuit 65 drives the scanner unit 66 in synchronization with, for example, a projection image clock signal input from the signal processing circuit 61. In addition, when a signal of an irradiation angle of a biaxial scanner 66A described later or the like is input from the scanner unit 66, the scanner drive circuit 65 drives the scanner unit 66 based on the signal so that the irradiation angle becomes a desired irradiation angle.

The scanner unit 66, for example, raster scans the surface of the data protection seal 100 with light (laser beam La) output from the light source unit 63. The scanner unit 66 includes, for example, a biaxial scanner 66A and an f θ lens 66B. The two-axis scanner 66A is, for example, a galvanometer mirror. The f θ lens 66B converts the constant speed scan by the dual axis scanner 66A into a constant speed linear scan of the spot moving on the focal plane (the surface of the data protective seal 100). It should be noted that the scanner unit 66 may include a single axis scanner and an f θ lens. In this case, preferably, a single axis platform is provided for moving the data protection seal 100 in a direction perpendicular to the scanning direction of the single axis scanner.

Next, an example of performing writing on the data protection seal 100 by the drawing device 1 will be described.

[ writing ]

First, the user prepares an uncolored data protection seal 100 and sets it in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform writing through the input unit 20. Then, the information processing unit 70 converts the image data 42 read out from the storage unit 40 into output setting values of the drawing unit 60, and inputs the output setting values obtained by the conversion to the drawing unit 60. The drawing unit 60 performs writing on the data protection seal 100 based on the input output setting value (see the upper diagram of fig. 5).

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal based on the image signal Din in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength. The signal processing circuit 61 outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light source 63A of the light source unit 63 in accordance with the light emission signal. At this time, the laser drive circuit 62 causes a laser beam La to be emitted from the light source 63A and scanned over, for example, the data protection seal 100. As a result, for example, the laser beam La having the wavelength λ 1 is absorbed by the photo-thermal converter in the cover layer 110, so that the cover layer 110 is brought to the writing temperature by the heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in the visible wavelength range. In this way, the drawing unit 60 performs writing on the data protection seal 100.

Next, an example of performing erasing on the data protection seal 100 by the drawing device 1 will be described.

[ Erase ]

First, the user prepares the data protection seal 100 on which writing has been performed as described above, and sets it in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform erasing through the input unit 20. Then, the information processing unit 70 sets the output set value so that the temperature of the cover layer 110 on which the erasing is to be performed satisfies the temperature condition suitable for the decoloring by the heat generated by the photothermal conversion agent. The drawing unit 60 performs erasing on the data protection seal 100 based on the input output setting value (see the lower diagram of fig. 5).

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light source 63A of the light source unit 63 in accordance with the light emission signal. At this time, the laser driving circuit 62 causes the laser beam La to be emitted from the light source 63A and to scan over the data protection seal 100. As a result, for example, the laser beam La having the wavelength λ 1 is absorbed by the light-heat converter in the cover layer 110, so that the cover layer 110 is brought to a temperature condition suitable for decoloring by heat generated by the light-heat converter, and the leuco pigment is separated from the developer and decolored. In this way, the drawing unit 60 performs erasing on the data protection seal 100.

[ Effect ]

Next, the effects of the data protection seal 100 and the drawing device 1 according to the present embodiment will be described.

In the case where important information such as a password and an encryption key is stored and stored on a recording medium connected to a computer for a long time, there is a problem that the stored information is stolen or becomes unreadable by a third party due to a hacking or a malfunction of a device. At present, the method of printing on paper and storing it is considered to be the safest. However, the risk of information leakage due to illegal viewing by a third party or the risk of print loss due to deterioration of paper or ink is not zero. For example, the disclosure described in the above-mentioned PTL1 can be conceived as a measure for suppressing illegal viewing by a third party. However, in the disclosure of PTL1, there is a problem that visualization cannot be achieved without using an infrared sensor.

In contrast, in the data protection seal 100 according to the present embodiment, confidential information can be hidden by attaching the data protection seal 100 to the data layer 210, developing the cover layer 110 in color to make the confidential information invisible, or making the cover layer 110 prevent the confidential information from being recognized. Further, by decoloring the cover layer 110 and visualizing the confidential information, the confidential information can be visually recognized in the visible wavelength range. Therefore, in the data protection seal 100 according to the present embodiment, confidential information can be visualized in the visible wavelength range.

In contrast, in the present embodiment, the protective layer 130 that protects the adhesive layer 120 is provided. This makes the data protection seal 100 easier to handle than if the protective layer 130 were not provided.

Further, in the present embodiment, the cover layer 110 includes a leuco pigment, a light-heat converter, a developer, and a polymer. Therefore, by irradiating the cover layer 110 with a laser beam having a light emission wavelength corresponding to the absorption wavelength of the photothermal conversion agent, and by heating the photothermal conversion agent, the cover layer 110 reaches the writing temperature, the developer and the leuco pigment are bonded to each other, and it becomes possible to change the leuco pigment into a color developed state in the visible wavelength range. Thus, confidential information may be hidden by rendering the overlay layer 110 colored to make the data layer 210 invisible, or by the overlay layer 110 preventing the confidential information from being identified. In addition, if the cover layer 110 is set to a temperature condition suitable for decoloring by heat generated by irradiating a laser beam, the developer and the leuco pigment are separated from each other, and the leuco pigment may be changed into a decolored state in a visible wavelength range. Accordingly, the visible image of the cover layer 110 is erased, the cover layer 110 becomes a decolored state, and the data layer 210 becomes a visible state, so that the confidential information can be visibly recognized in the visible wavelength range.

Further, in the present embodiment, the data layer 210 is a printed layer in which confidential information is irreversibly fixed on the base layer 220. This makes it possible to visually identify the confidential information printed on the data layer 210 in the visible wavelength range by converting the cover layer 110 into the decolored state and converting the data layer 210 into the visible state.

Further, in the drawing device 1 according to the present embodiment, writing or erasing is performed on the cover layer 110 by irradiating the cover layer 110 with the laser beam La emitted from the light source unit 63. By performing writing on the cover layer 110 by the drawing device 1, it is possible to make the confidential information on the data layer 210 invisible and hide the confidential information by preventing the confidential information from being recognized by the cover layer 110. Further, by performing erasing on the cover layer 110 by the drawing device 1, the data layer 210 can be made visible and the confidential information can be visually identified. Therefore, in the drawing device 1 according to the present embodiment, the confidential information can be visualized in the visible wavelength range.

<2 > modification of the first embodiment

A modification of the data protection seal 100 according to the above embodiment will be described below.

[ modification A ]

In the above-described embodiment, in the case where the visible image data is acquired by the image recognition unit 50, the information processing unit 70 may convert the processed image data obtained by performing predetermined processing on the visible image data read out from the storage unit 40 into the image data of the cover layer 110. The processed image data is, for example, grayscale image data having a pattern different from that of the visible image data of the data layer 210. For example, reverse image data in which visible image data is reversed as shown in fig. 6 may be used, or complex patterned image data as shown in fig. 7 may be used, for example.

On the cover layer 110, if, for example, the reverse image data of the reverse visible image data as shown in fig. 6 is written, the confidential information is in a state of being visible through the cover layer 110 as a whole, but due to the cover layer 110, the confidential information appears as a visible image (for example, a solid image) different from the original visible image of the confidential information. Further, on the cover layer 110, if, for example, complex patterned image data as shown in fig. 7 is written, a part of the confidential information is in a state of being visible through the cover layer 110, but the confidential information appears as a visible image (for example, a striped image) different from the original visible image of the confidential information due to the cover layer 110. Therefore, by performing writing on the cover layer 110, the confidential information can be hidden by the cover layer 110 as in the above-described embodiment. Instead, by performing erasure on the overlay layer 110, the confidential information can be visually identified through the overlay layer 110 as in the above-described embodiment.

[ modification B ]

In the above-described embodiment and its modifications, the covering layer 110 may include, for example, a photochromic material. Examples of the photochromic material include diarylvinylene compounds and the like. The photochromic material is configured to switch between a colored state (colored state) and a bleached state in a visible wavelength range. The photochromic material has an absorption peak in an ultraviolet region in a decolored state, and when ultraviolet rays having a wavelength in the vicinity of the absorption peak are irradiated, the absorption peak shifts to a visible light region and changes to a colored state. Therefore, by irradiating ultraviolet rays having a wavelength in the vicinity of the absorption peak in the decolored state to develop the color of the photochromic material, the cover layer 110 is not visible, or by preventing the confidential information from being recognized by the cover layer 110, the confidential information can be concealed. In addition, by irradiating strong visible light near the absorption peak wavelength in a colored state to decolorize the photochromic material and visualize the cover layer 110, confidential information can be visually recognized. Therefore, in the data protection seal 100 according to the present modification, confidential information can be visualized also in the visible wavelength range.

[ modification C ]

In the above-described embodiment and its modifications, the cover layer 110 may include, for example, a material configured to control light transmittance due to phase change in the visible wavelength range, or a material configured to switch between a color-developed state and a color-decolored state due to phase change in the visible wavelength range. As such a material, a phase change material configured to mutually convert between two phases of an amorphous phase and a crystalline phase may be used. For example, germanium-antimony-tellurium-alloys Ge₂Sb₂Te₅The film turned into a transparent amorphous phase when heated to an elevated temperature of about 600 c and quenched, and turned into an opaque crystalline phase when heated to an intermediate temperature of about 160 c and slowly cooled. By using such a phase change material for the capping layer 110, the amorphous phase may be a visible state of the confidential information, and the crystalline phase may be an invisible state of the confidential information. The confidential information may be hidden by changing the phase change material to a crystalline phase to make the cover layer 110 opaque, or by preventing the confidential information from being recognized by the cover layer 110. In addition, by changing the phase change material to an amorphous phase to make the cover layer 110 transparent, it can be seenConfidential information is identified. Therefore, in the data protection seal 100 according to the present modification, the confidential information can be visualized in the visible wavelength range.

[ modification D ]

In the above-described embodiment and its variations, the data protecting seal 100 may include one or more cover layers having a similar function to the cover layer 110, in addition to the cover layer 110. Data protective seal 100 may include, for example, cover layers 110 and 140, as shown in FIG. 8. Data protective seal 100 may include a thermally insulating adhesive layer 150 between cover layer 110 and cover layer 140. The thermal barrier adhesive layer 150 is a layer of a pressure sensitive adhesive or an adhesive for attaching the cover layer 140 to the cover layer 110, and is a layer capable of preventing heat from being transmitted between the cover layer 110 and the cover layer 140. The heat-insulating adhesive layer 150 includes, for example, a pressure-sensitive adhesive or an adhesive containing a synthetic resin having a thermal conductivity of 0.3(W/m · K) or less. The thickness of the adiabatic adhesive layer 150 is desirably 3 μm or more, and more desirably 6 μm or more.

The overlay layer 140 is a layer for hiding confidential information by being attached to a document or the like. The cover layer 140 is configured to switch between a colored state and a bleached state in the visible wavelength range. Preferably, the color of the cover layer 140 when developed is black having an optical density of 1.5 or more. It should be noted that the optical density of the colors at the time of development of overlay layer 140 may be a density at which it is visually impossible to identify the visible image of data layer 210. The visible image of overlay layer 140 may include multiple colors or may include a single color. In case the visible image of the data layer 210 comprises a single color, the color difference Δ E between the data layer 210 and the cover layer 110 is preferably 1.2 or less.

It should be noted that the color difference Δ E between the data layer 210 and the overlay layer 110 may be such that the visible image of the data layer 210 is not visually recognizable. The color difference Δ E is represented by the following formula, where L α a b color space is represented by (L ×)₁,a*₁,b*₁) And (L;)₂,a*₂,b*₂) Representing two colors.

ΔE*＝((L*₂-L*₁)²+(a*₂-a*₁)²+(b*₂-b*₁)²)^1/2

When the cover layer 140 attached to a document or the like is in a colored state in a visible wavelength range, the cover layer 140 prevents confidential information from being visually recognized or recognized. In the case where the cover layer 140 prevents the confidential information from being visually recognized, the cover layer 140 makes a part or all of the confidential information invisible. In contrast, in the case where the cover layer 140 prevents the confidential information from being recognized, a part or all of the confidential information may be in a state of being visible through the cover layer 140, but the confidential information appears as a visible image different from the original visible image of the confidential information due to the cover layer 140.

Further, when the cover layer 140 attached to a document or the like is in a decolored state in visible wavelengths, the cover layer 140 cannot prevent confidential information from being visually recognized. At this time, the confidential information is in a state of being visible through the cover layer 140.

The cover layer 140 includes, for example, a leuco pigment and a photothermal conversion agent for generating heat at the time of writing. The cover layer 140 also includes, for example, a developer and a polymer.

The leuco pigment is combined with the developer to become a colored state in the visible wavelength range, or is separated from the developer to become a decolored state in the visible wavelength range. When the cover layer 140 reaches its writing temperature by heat, the leuco pigment contained in the cover layer 140 is combined with a developer and develops a predetermined color in a visible wavelength range. Further, the cover layer 140 is transparent in a decolored state in a visible wavelength range. The photothermal conversion agent absorbs light in, for example, the near infrared region (700nm to 2500nm), and generates heat. For example, the photothermal conversion agent included in the cover layer 140 has an absorption peak at a wavelength λ 2(λ 2 ≠ λ 1, 700nm ≦ λ 2 ≦ 2500 nm). In the present modification, in the case where the cover layer 110 is provided at a position closer to the protective layer 130 than the cover layer 140, it is preferable that the wavelength λ 1 of the absorption peak of the light-to-heat converter contained in the cover layer 110 be longer than the wavelength λ 2 of the absorption peak of the light-to-heat converter contained in the cover layer 140. This is for the purpose that, for example, when writing or erasing is performed on the cover layer 110 via the cover layer 140 by using the drawing device 1 including the drawing unit 60 of fig. 9 described later, it is difficult for the cover layer 140 to absorb a laser beam having the wavelength λ 1.

Next, the drawing unit 60 that performs writing and erasing on the data protection seal 100 including the cover layers 110 and 140 as shown in fig. 8 will be described. Fig. 9 shows a schematic configuration example of the drawing unit 60 that performs writing and erasing on the data protection seal 100 shown in fig. 8. The drawing unit 60 includes, for example, a signal processing circuit 61, a laser driving circuit 62, a light source unit 63, an adjustment mechanism 64, a scanner driving circuit 65, and a scanner unit 66. The drawing unit 60 performs drawing on the data protection seal 100 by controlling the output of the light source unit 63 based on the output set value input from the information processing unit 70.

The signal processing circuit 61 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates, for example, a pixel signal Dout corresponding to a scanner operation of the scanner unit 66 from the image signal Din. The pixel signal Dout causes the light source unit 63 (for example, light sources 63A and 63B described later) to output a laser beam having a power corresponding to an output set value. The signal processing circuit 61 controls the peak value of the current pulse to be applied to the light source unit 63 (for example, the light sources 63A and 63B) in accordance with the signal Dout together with the laser driving circuit 62.

The laser drive circuit 62 drives each of the light sources 63A and 63B of the light source unit 63 in accordance with the pixel signal Dout, for example. The laser drive circuit 62 controls, for example, the luminance (luminance) of a laser beam for drawing an image corresponding to the pixel signal Dout. The laser drive circuit 62 includes, for example, a drive circuit 62A that drives the light source 63A and a drive circuit 62B that drives the light source 63B. The light sources 63A and 63B each perform writing and erasing on the data protection seal 100 by outputting a laser beam of power corresponding to an output set value to the data protection seal 100. The light sources 63A and 63B each emit a laser beam in the near infrared region. The light source 63A is, for example, a laser diode that emits a laser beam La having a wavelength λ 1. The light source 63B is, for example, a laser diode that emits a laser beam Lb having a wavelength λ 2.

The light source unit 63 has a plurality of light sources that emit light of different wavelengths in the near infrared region. The light source unit 63 includes, for example, two light sources 63A and 63B. The light source unit 63 further includes, for example, an optical system that synthesizes laser beams emitted from a plurality of light sources (for example, two light sources 63A and 63B). As such an optical system, the light source unit 63 includes, for example, a mirror 63a, a dichroic mirror 63b, and a lens 63 e.

For example, each of the laser beams La and Lb emitted from the two light sources 63A and 63B is converted into substantially parallel light (collimated light) by the collimator lens. Then, for example, the laser beam La is reflected by the reflecting mirror 63a and further reflected by the dichroic mirror 63b, and the laser beam Lb passes through the dichroic mirror 63b, whereby the laser beam La and the laser beam Lb are synthesized together. The laser beam La and the combined light Lm of the laser beam La are transmitted through the dichroic mirror 63 c. The light source unit 63 outputs, for example, synthesized light Lm obtained by synthesis by an optical system to the scanner unit 66.

The adjustment mechanism 64 is a mechanism for adjusting the focus of the synthesized light Lm emitted from the light source unit 63. The adjustment mechanism 64 is a mechanism for adjusting the position of the lens 63e by a manual operation of a user, for example. It should be noted that the adjustment mechanism 64 may be a mechanism for adjusting the position of the lens 63e by mechanical manipulation.

The scanner drive circuit 65 drives the scanner unit 66 in synchronization with, for example, a projection image clock signal input from the signal processing circuit 61. When a signal of the irradiation angle of the biaxial scanner 66A or the like is input from the scanner unit 66, the scanner drive circuit 65 drives the scanner unit 66 based on the signal so that the irradiation angle becomes a desired irradiation angle.

The scanner unit 66, for example, raster scans the data protecting the surface of the seal 100 with the synthesized light Lm output from the light source unit 63. The scanner unit 66 includes, for example, a biaxial scanner 66A and an f θ lens 66B. The two-axis scanner 66A is, for example, a galvanometer mirror. The f θ lens 66B converts the constant speed scan by the dual axis scanner 66A into a constant speed linear scan of the spot moving on the focal plane (the surface of the data protective seal 100). It should be noted that the scanner unit 66 may include a single axis scanner and an f θ lens. In this case, preferably, a single axis platform is provided for moving the data protection seal 100 in a direction perpendicular to the scanning direction of the single axis scanner.

Next, an example of performing writing on the data protection seal 100 by the drawing device 1 will be described.

[ writing ]

First, the user prepares an uncolored data protection seal 100 and sets it in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform writing through the input unit 20. Then, the information processing unit 70 converts the image data 42 read out from the storage unit 40 into output setting values of the drawing unit 60, and inputs the output setting values obtained by the conversion to the drawing unit 60. The drawing unit 60 performs writing on the cover layers 110 and 140 of the data protection seal 100 based on the input output setting value.

The laser drive circuit 62 drives the light sources 63A and 63B of the light source unit 63 according to the light emission signal. At this time, the laser driving circuit 62 causes the laser light La to be emitted from the light source 63A, causes the laser light Lb to be emitted from the light source 63B, and causes the synthesized light Lm to scan on the data protection seal 100. As a result, the laser beam La of the wavelength λ 1 contained in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 110, so that the cover layer 110 is brought to the writing temperature by the heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in the visible wavelength range (upper diagram of fig. 10). Further, the laser beam Lb of the wavelength λ 2 included in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 140, so that the cover layer 140 is brought to a writing temperature by heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in a visible wavelength range (the lower diagram of fig. 10). In this way, the drawing unit 60 performs writing on the data protection seal 100 shown in fig. 8.

Next, an example of performing erasing on the data protection seal 100 by the drawing device 1 will be described.

[ Erase ]

First, the user prepares the data protection seal 100, on which writing has been performed as described above, and sets it in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform erasing through the input unit 20. Then, the information processing unit 70 sets the output set value so that the temperature of the cover layer 110, 140 on which the erasing is to be performed satisfies the temperature condition suitable for the decoloring with the heat generated by the photothermal conversion agent. The graphic unit 60 performs erasing on the data protection seal 100 based on the input output setting value.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light sources 63A and 63B of the light source unit 63 according to the light emission signal. At this time, the laser driving circuit 62 causes the laser light La to be emitted from the light source 63A, causes the laser light Lb to be emitted from the light source 63B, and causes the synthesized light Lm to scan on the data protection seal 100. As a result, the laser light La of the wavelength λ 1 included in the synthesized light Lm is absorbed by the light-heat converter inside the cover layer 110, so that the cover layer 110 is brought to a temperature condition suitable for decoloring by the heat generated by the light-heat converter, and the leuco pigment is separated from the developer and decolored (upper diagram of fig. 11). Further, the laser light Lb of the wavelength λ 2 included in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 140, so that the cover layer 140 is brought to a temperature condition suitable for decoloring by heat generated by the photo-thermal converter, and the leuco pigment is separated from the developer and decolored (the lower diagram of fig. 11). In this way, the drawing unit 60 performs erasing on the data protection seal 100.

[ Effect ]

Next, the effects of the data protection seal 100 and the drawing device 1 according to the present modification will be described.

In the data protection seal 100 according to the present modification, confidential information may be hidden by attaching the data protection seal 100 to the data layer 210, developing the cover layers 110 and 140 in color to make the confidential information invisible, or making the cover layers 110 and 140 prevent the confidential information from being recognized. In addition, by decoloring the cover layers 110 and 140 and visualizing the confidential information, the confidential information can be visually recognized in the visible wavelength range. Therefore, in the data protection seal 100 according to the present modification, the confidential information can be visualized in the visible wavelength range.

Further, in the present modification, the cover layers 110 and 140 each include a leuco pigment, a light-heat converter, a developer, and a polymer. Therefore, by irradiating the covering layers 110 and 140 with a laser beam having a light emission wavelength corresponding to the absorption wavelength of the photothermal conversion agent, and by heating the photothermal conversion agent, the covering layers 110 and 140 each reach a writing temperature, the developer and the leuco pigment are bonded to each other, and it becomes possible to change the leuco pigment into a color developed state in the visible wavelength range. Thus, confidential information may be hidden by rendering each of overlay layers 110 and 140 colored to make data layer 210 invisible, or by protecting confidential information from being recognized by overlay layers 110 and 140. In addition, if the covering layers 110 and 140 are each set to a temperature condition suitable for decoloring by heat generated by irradiating a laser beam, the developer and the leuco pigment are separated from each other, and the leuco pigment may be brought into a decolored state in a visible wavelength range. Accordingly, the visible image of each of the cover layers 110 and 140 is erased, the cover layers 110 and 140 each become a decolored state, and the data layer 210 becomes a visible state, so that confidential information can be visibly recognized in the visible wavelength range.

In addition, in the drawing device 1 of the present modification, writing or erasing on the cover layers 110, 140 is performed by irradiating the cover layer 110 with the combined light Lm emitted from the light source unit 63. By writing the capping layers 110 and 140 by the drawing device 1 according to the present modification, the confidential information on the data layer 210 can be made invisible, and by preventing the confidential information from being recognized by the capping layers 110 and 140, the confidential information can be concealed. Further, by performing the erasing on the cover layers 110, 140 by the drawing device 1, the data layer 210 can be visualized and the confidential information can be visually identified. Therefore, in the drawing device 1 according to the present modification, the confidential information can be visualized in the visible wavelength range.

In the present modification, since heat insulating adhesive layer 150 is provided between cover layer 110 and cover layer 140, heat propagation between cover layer 110 and cover layer 140 is prevented by heat insulating adhesive layer 150. Therefore, for example, when color development or decoloration is performed on the cover layer 110, it is possible to prevent color development or decoloration from being erroneously performed on the cover layer 140.

[ modification E ]

In the above-described embodiment and its modifications, for example, as shown in fig. 12, a reversible data layer 230 may be provided instead of the data layer 210 in the document 200. The reversible data layer 230 is configured to record confidential information as a visible image and includes, for example, a reversible material configured to switch between a colored state and a bleached state in the visible wavelength range. The reversible data layer 230 records the confidential information as a visible image. Due to the color development of the reversible material, confidential information is recorded as a visible image on the reversible data layer 230. At this time, the optical density of the color at which the cover layer 110 is developed may be a density at which the visible image of the reversible data layer 230 cannot be visually recognized. The visible image of the overlay layer 110 may include multiple colors or may include a single color. In case the visible image of the reversible data layer 230 comprises a single color, the color difference Δ E between the reversible data layer 230 and the cover layer 110 is preferably 1.2 or less. It should be noted that the color difference Δ E between the data layer 210 and the overlay layer 110 may be such that the visible image of the data layer 210 is not visually recognizable.

Reversible data layer 230 includes, for example, a leuco pigment and a light-to-heat converter for generating heat upon writing. Reversible data layer 230 also includes, for example, a developer and a polymer.

The leuco pigment is combined with the developer to become a colored state in the visible wavelength range, or is separated from the developer to become a decolored state in the visible wavelength range. When the reversible data layer 230 reaches its writing temperature by heating, the leuco pigment included in the reversible data layer 230 is combined with a developer and develops a predetermined color in a visible wavelength range. In addition, the reversible data layer 230 is transparent in a decolored state in a visible wavelength range. The photothermal conversion agent absorbs light in, for example, the near infrared region (700nm to 2500nm), and generates heat. For example, the light-to-heat converter contained in reversible data layer 230 has an absorption peak at wavelength λ 2. That is, the cover layer 110 includes a reversible material with a switching condition that is different from the switching condition of the reversible data layer 230. The cover layer 110 is colored or decolored when a laser beam having a wavelength of λ 1 is irradiated, and the reversible data layer 230 is colored or decolored when a laser beam having a wavelength of λ 2 is irradiated. In the present modification, in the case where reversible data layer 230 is provided below cover layer 110, wavelength λ 2 of the absorption peak of the light-to-heat converter included in reversible data layer 230 is preferably longer than wavelength λ 1 of the absorption peak of the light-to-heat converter included in cover layer 110. That is, it is preferable that the wavelength λ 1 of the absorption peak of the light-to-heat converter included in the cover layer 110 is shorter than the wavelength λ 2 of the absorption peak of the light-to-heat converter included in the reversible data layer 230. This is for making it difficult for the cover layer 110 to absorb a laser beam having a wavelength λ 2, for example, when writing or erasing is performed on the reversible data layer 230 via the cover layer 110 by using the drawing device 1 including the drawing unit 60 of fig. 9.

In the present modification, the adhesive layer 120 is preferably a layer for attaching the cover layer 110 to the reversible data layer 230, and is a heat-insulating adhesive layer that prevents heat from propagating between the cover layer 110 and the reversible data layer 230. In this case, the adhesive layer 120 includes, for example, a pressure-sensitive adhesive or an adhesive containing a synthetic resin having a thermal conductivity of 0.3(W/m · K) or less. The thickness of the adiabatic adhesive layer 150 is desirably 3 μm or more, and more desirably 6 μm or more.

Next, an example of performing writing on the reversible data layer 230 and the data protection seal 100 by the drawing device 1 will be described.

[ writing ]

First, the user prepares the uncolored reversible data layer 230 and the data protection seal 100 and sets them in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform writing through the input unit 20. Then, the information processing unit 70 converts the two pieces of image data read out from the storage unit 40 into the output setting values of the drawing unit 60, and inputs the two output setting values obtained by the conversion to the drawing unit 60. The drawing unit 60 performs writing on the reversible data layer 230 and the data protection seal 100 based on the two input output setting values.

The signal processing circuit 61 of the drawing unit 60 acquires the two output setting values input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal based on the image signal Din in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength. The signal processing circuit 61 outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The drive circuit 62A drives the light source 63A of the light source unit 63 in accordance with a light emission signal generated from one of the output setting values. The drive circuit 62B drives the light source 63B of the light source unit 63 in accordance with the light emission signal generated from the other output setting value. At this time, the driving circuit 62A causes the laser beam La to be emitted from the light source 63A, the driving circuit 62B causes the laser beam Lb to be emitted from the light source 63B, and the synthesized light Lm is scanned on the data protection seal 100. As a result, the laser beam La having the wavelength λ 1 included in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 110, so that the cover layer 110 is brought to the writing temperature by the heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in the visible wavelength range (the lower diagram of fig. 13). Further, the laser beam Lb having the wavelength λ 2 included in the synthesized light Lm is absorbed by the photo-thermal converter in the reversible data layer 230, so that the reversible data layer 230 is brought to a writing temperature by heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in a visible wavelength range (upper diagram of fig. 13). In this way, the drawing unit 60 performs writing on the reversible data layer 230 and the data protection seal 100 shown in fig. 12.

Next, an example of performing erasing on the reversible data layer 230 and the data protection seal 100 by the drawing device 1 will be described.

[ Erase ]

First, the user prepares the reversible data layer 230 and the data protection seal 100 on which writing has been performed as described above, and sets them in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform erasing on the data protection seal 100 through the input unit 20. Then, the information processing unit 70 sets the output set value so that the temperature of the cover layer 110 on which the erasing is to be performed satisfies the temperature condition suitable for the decoloring by the heat generated by the photothermal conversion agent. The graphic unit 60 performs erasing on the data protection seal 100 based on the input output setting value.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light source 63A of the light source unit 63 in accordance with the light emission signal. At this time, the laser driving circuit 62 causes the laser beam La to be emitted from the light source 63A and to scan over the data protection seal 100. As a result, for example, the laser beam La is absorbed by the light-heat converter in the cover layer 110, so that the cover layer 110 is subjected to a temperature condition suitable for decoloring by the heat generated by the light-heat converter, and the leuco pigment is separated from the developer and decolored (upper diagram of fig. 14). In this way, the drawing unit 60 performs erasing on the data protection seal 100.

It should be noted that at this time, the user may also instruct the information processing unit 70 to perform erasure on the reversible data layer 230 through the input unit 20. In this case, the information processing unit 70 converts the image data 42 read out from the storage unit 40 into output setting values of the drawing unit 60, and inputs the output setting values obtained by the conversion to the drawing unit 60. At this time, the information processing unit 70 sets the output setting value so that the temperature of the reversible data layer 230 on which erasing is to be performed satisfies the temperature condition suitable for decoloring by the heat generated by the photothermal conversion agent. The drawing unit 60 performs erasing on the reversible data layer 230 based on the input output setting.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light source 63B of the light source unit 63 in accordance with the light emission signal. At this time, the laser drive circuit 62 causes the laser beam Lb to be emitted from the light source 63B, and causes the laser beam Lb to scan over the data protection seal 100. As a result, for example, the laser beam Lb is absorbed by the photo-thermal converter in the reversible data layer 230, so that the reversible data layer 230 is brought to a temperature condition suitable for decoloring with the leuco pigment separated from the developer and decolored (lower diagram of fig. 14). In this manner, drawing unit 60 performs an erase on reversible data layer 230.

[ Effect ]

Next, the effects of the data protection seal 100 and the drawing device 1 according to the present modification will be described.

In the data protection seal 100 according to the present modification, confidential information may be hidden by attaching the data protection seal 100 to the reversible data layer 230, coloring the cover layer 110 to make the confidential information invisible, or allowing the cover layer 110 to prevent the confidential information from being recognized. Further, by decoloring the cover layer 110 and visualizing the confidential information, the confidential information can be visually recognized in the visible wavelength range. Therefore, in the data protection seal 100 according to the present modification, the confidential information can be visualized in the visible wavelength range.

In addition, in the present modification, the cover layer 110 includes a leuco pigment, a light-heat converter, a developer, and a polymer. Therefore, by irradiating the cover layer 110 with a laser beam having a light emission wavelength corresponding to the absorption wavelength of the photothermal conversion agent, and by heating the photothermal conversion agent, the cover layer 110 reaches the writing temperature, the developer and the leuco pigment are bonded to each other, and it becomes possible to change the leuco pigment into a color developed state in the visible wavelength range. Thus, confidential information may be hidden by rendering overlay layer 110 colored to make reversible data layer 230 invisible, or by overlay layer 110 preventing the confidential information from being identified. In addition, if the cover layer 110 is set to a temperature condition suitable for decoloring by heat generated by irradiating a laser beam, the developer and the leuco pigment are separated from each other, and the leuco pigment may be changed into a decolored state in a visible wavelength range. Accordingly, the visible image of the cover layer 110 is erased, the cover layer 110 becomes a decolored state, and the reversible data layer 230 becomes a visible state, so that the confidential information can be visibly recognized in the visible wavelength range. In addition, since a laser beam of a specific wavelength is necessary for the erasing process on the cover layer 110, a data protection seal 100 of a higher security level can be realized than the case where the visualization is simply performed by raising the temperature. That is, in the case where it is attempted to steal confidential information by a method other than the normal method, for example, it is attempted to heat the entire data protection seal 100 to bring the cover layer 110 into a decolored state, the confidential information written in the reversible data layer 230 is also decolored at the same time, so that there is no risk that the confidential information is stolen.

In the present variation, similar to the cover layer 110, the reversible data layer 230 includes a reversible material configured to switch between a colored state and a bleached state in the visible wavelength range. However, reversible data layer 230 includes a reversible material having a different switching condition than the switching condition of cover layer 110. That is, the cover layer 110 includes a reversible material having a different switching condition than the reversible data layer 230. As a result, the drawing device 1 can perform the conversion between color development and decoloring only on one of the reversible data layer 230 or the cover layer 110. Therefore, the drawing device 1 can control the visualization and the hiding of confidential information by merely switching between the coloring and the decoloring of the cover layer 110. Further, the drawing device 1 is also capable of performing rewriting on the reversible data layer 230.

In the present modification, when the adhesive layer 120 is the above-described heat-insulating adhesive layer, the adhesive layer 120 prevents heat propagation between the cover layer 110 and the reversible data layer 230. Therefore, for example, when color development or decoloration is performed on the cover layer 110, it is possible to prevent color development or decoloration from being erroneously performed on the reversible data layer 230.

In the present modification, a protective layer 130 that protects the adhesive layer 120 is provided. This makes it easier to handle the data protection seal 100 than if the protective layer 130 were not provided.

<3. second embodiment >

[ arrangement ]

A document 300 according to a second embodiment of the present disclosure will be described. Fig. 15 shows a schematic configuration example of a document 300 according to the present embodiment. The document 300 includes, for example: a base layer 310; and a reversible data layer 320, a thermally insulating adhesive layer 330, and a cover layer 340 formed over the base layer 310. The reversible data layer 320, the adiabatic adhesive layer 330, and the cover layer 340 are stacked in this order over the base layer 310. The positions of the reversible data layer 320 and the overlay layer 340 may be exchanged. A thermally insulating adhesive layer 330 and a cover layer 340 are disposed opposite the reversible data layer 320. A cover layer 340 is disposed over the reversible data layer 320.

The base layer 310 includes an opaque material such as paper or synthetic resin. The thermal insulating adhesive layer 330 is a layer for attaching the cover layer 340 to the reversible data layer 320, and is a layer capable of preventing heat from propagating between the cover layer 340 and the reversible data layer 320. The heat-insulating adhesive layer 330 includes, for example, a pressure-sensitive adhesive or an adhesive containing a synthetic resin having a thermal conductivity of 0.3(W/m · K) or less. The thickness of the adiabatic adhesive layer 330 is desirably 3 μm or more, and more desirably 6 μm or more.

Reversible data layer 320 and cover layer 340 are each configured to switch between a colored state and a bleached state in the visible wavelength range. The cover layer 340 includes a reversible material having a switching condition different from that of the reversible data layer 320. That is, reversible data layer 320 comprises a reversible material having a different switching condition than the switching condition of cover layer 340. At this time, the optical density of the color when the cover layer 340 is developed may be a density at which the visible image of the reversible data layer 320 cannot be visually recognized. The visible image of the overlay layer 340 may include multiple colors or may include a single color. In the case of a visible image of the reversible data layer 320, the color difference Δ E between the reversible data layer 320 and the overlay layer 340 is preferably 1.2 or less. It should be noted that the color difference Δ E between the reversible data layer 320 and the overlay layer 340 may be such that a visible image of the reversible data layer 320 may not be visually recognizable.

Overlay layer 340 is a layer used to hide confidential information written on reversible data layer 320. When cover layer 340 is in a colored state in the visible wavelength range, cover layer 340 prevents confidential information from being visibly identified or recognized. In the case where the overlay layer 340 prevents the confidential information from being visibly recognized, a part or all of the confidential information is made invisible by the overlay layer 340. In contrast, in the case where the overlay layer 340 prevents the confidential information from being recognized, a part or all of the confidential information may be in a state of being visible through the overlay layer 340, but the confidential information appears as a visible image different from the original visible image of the confidential information due to the overlay layer 340.

Further, when the cover layer 340 is in a decolored state in a visible wavelength, the cover layer 340 cannot prevent confidential information from being visually recognized. At this time, the confidential information is in a state of being visible through the cover layer 340.

Reversible data layer 320 includes, for example, a leuco pigment and a light-to-heat converter for generating heat upon writing. Reversible data layer 320 also includes, for example, a developer and a polymer.

The cover layer 340 includes, for example, a leuco pigment and a photothermal conversion agent for generating heat at the time of writing. The cover layer 340 also includes, for example, a developer and a polymer.

The leuco pigment is combined with the developer to become a colored state in the visible wavelength range, or is separated from the developer to become a decolored state in the visible wavelength range. When the capping layer 340 reaches its writing temperature by heating, the leuco pigment included in the capping layer 340 is combined with a developer and develops a predetermined color in a visible wavelength range. Further, the cover layer 340 is transparent in a decolored state in a visible wavelength range. The photothermal conversion agent absorbs light in, for example, the near infrared region (700nm to 2500nm), and generates heat. For example, the photothermal conversion agent included in the covering layer 340 has an absorption peak at a wavelength λ 2(700nm ≦ λ 2 ≦ 2500 nm). In the present embodiment, in the case where reversible data layer 320 is disposed below cover layer 340, wavelength λ 1 of the absorption peak of the light-to-heat converter included in reversible data layer 320 is preferably longer than wavelength λ 2 of the absorption peak of the light-to-heat converter included in cover layer 340. This is for making it difficult for the cover layer 340 to absorb, for example, a laser beam having a wavelength λ 1 when writing or erasing is performed on the reversible data layer 320 via the cover layer 340 by using the drawing device 1 including the drawing unit 60 of fig. 9. Further, in the present embodiment, in the case where cover layer 340 is disposed below reversible data layer 320, wavelength λ 2 of the absorption peak of the photothermal conversion agent contained in cover layer 340 is preferably longer than wavelength λ 1 of the absorption peak of the photothermal conversion agent contained in reversible data layer 320. This is to make it difficult for the reversible data layer 320 to absorb a laser beam having a wavelength λ 2, for example, when writing or erasing is performed on the cover layer 340 via the reversible data layer 320 by using the drawing device 1 including the drawing unit 60 of fig. 9.

Next, an example of performing writing on the reversible data layer 320 and the cover layer 340 by the drawing device 1 shown in fig. 9 will be described.

[ writing ]

First, the user prepares the uncolored reversible data layer 320 and the overlay layer 340 and sets them in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform writing through the input unit 20. Then, the information processing unit 70 converts the two pieces of image data read out from the storage unit 40 into the output setting values of the drawing unit 60, and inputs the two output setting values obtained by the conversion to the drawing unit 60. The drawing unit 60 performs writing on the reversible data layer 320 and the overlay layer 340 based on the two input output setting values.

The drive circuit 62A drives the light source 63A of the light source unit 63 in accordance with a light emission signal generated from one of the output setting values. The drive circuit 62B drives the light source 63B of the light source unit 63 in accordance with the light emission signal generated from the other output setting value. At this time, the driving circuit 62A causes the laser beam La to be emitted from the light source 63A, the driving circuit 62B causes the laser beam Lb to be emitted from the light source 63B, and the synthesized light Lm is scanned on the document 300. As a result, the laser beam La having the wavelength λ 1 included in the synthesized light Lm is absorbed by the photo-thermal converter in the reversible data layer 320, so that the reversible data layer 320 is brought to the writing temperature by the heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in the visible wavelength range (upper diagram of fig. 16). Further, the laser beam Lb having the wavelength λ 2 included in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 340, so that the cover layer 340 is brought to a writing temperature by heat generated by the photo-thermal converter, the leuco pigment is combined with the developer, and a predetermined color is developed in a visible wavelength range (the lower diagram of fig. 16). That is, the light source 63B emits a laser beam having a condition in which the color development and decoloration reaction of the reversible material in the reversible data layer 320 does not occur, and in which the color development reaction of the reversible material in the cover layer 340 occurs. Thus, light source 63A performs writing on reversible data layer 320 shown in FIG. 15, and light source 63B performs writing on cap layer 340 shown in FIG. 15.

Next, an example of performing erasing on the cover layer 340 by the drawing device 1 shown in fig. 9 will be described.

[ Erase ]

First, the user prepares the reversible data layer 320 and the cover layer 340 on which writing has been performed as described above, and sets them in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform erasure of the cover layer 340 through the input unit 20. Then, the information processing unit 70 sets the output setting value so that the temperature of the cover layer 340 on which the erasing is to be performed satisfies the temperature condition suitable for the decoloring by the heat generated by the photothermal conversion agent. The drawing unit 60 performs decoloring on the cover layer 340 based on the input output set value.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light source 63A of the light source unit 63 in accordance with the light emission signal. At this time, the laser drive circuit 62 causes the laser beam La to be emitted from the light source 63A, and causes the laser beam La to scan over the document 300, for example. As a result, for example, the laser beam La is absorbed by the light-heat converter in the cover layer 340, so that the cover layer 340 is brought to a temperature condition suitable for decoloring with the heat generated by the light-heat converter, and the leuco pigment is separated from the developer and decolored (upper diagram of fig. 17). That is, the laser beam emitted by the light source 63B has a condition in which the coloring and decoloring reactions of the reversible material in the reversible data layer 320 do not occur, and the decoloring reaction of the reversible material in the cover layer 340 occurs. Thus, light source 63A performs erasure on reversible data layer 320 shown in FIG. 15, and light source 63B performs erasure on overlay layer 340 shown in FIG. 15.

Note that at this time, the user may also instruct the information processing unit 70 to perform erasure on the reversible data layer 320 through the input unit 20. In this case, the information processing unit 70 converts the image data 42 read out from the storage unit 40 into output setting values of the drawing unit 60, and inputs the output setting values obtained by the conversion to the drawing unit 60. At this time, the information processing unit 70 sets the output setting value so that the temperature of the reversible data layer 320 on which erasing is to be performed satisfies the temperature condition suitable for decoloring by the heat generated by the photothermal conversion agent. The drawing unit 60 performs erasing on the reversible data layer 320 based on the input output setting.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light source 63B of the light source unit 63 in accordance with the light emission signal. At this time, the laser drive circuit 62 causes the laser beam Lb to be emitted from the light source 63B, and causes the laser beam Lb to scan over the document 300, for example. As a result, for example, the laser beam Lb is absorbed by the photo-thermal converter in the reversible data layer 320, so that the reversible data layer 320 is brought to a temperature condition suitable for decoloring with the leuco pigment separated from the developer and decolored (lower diagram of fig. 17). In this manner, drawing unit 60 performs an erase on reversible data layer 320.

[ Effect ]

Next, effects of the document 300 and the drawing device 1 according to the present embodiment will be described.

In the document 300 according to the present modification, the overlay layer 340 may be colored to make the confidential information invisible, or the overlay layer 340 may be allowed to prevent the confidential information from being recognized. In addition, by decoloring the cover layer 340 and visualizing the confidential information, the confidential information can be visually recognized in the visible wavelength range. Therefore, in the document 300 according to the present modification, the confidential information can be visualized in the visible wavelength range.

Further, in the present embodiment, the cover layer 340 includes a leuco pigment, a light-heat converter, a developer, and a polymer. Therefore, by irradiating the cover layer 340 with a laser beam having a light emission wavelength corresponding to the absorption wavelength of the photothermal conversion agent, and by heating the photothermal conversion agent, the cover layer 340 reaches the writing temperature, the developer and the leuco pigment are bonded to each other, and it becomes possible to change the leuco pigment into a color developed state in the visible wavelength range. Thus, confidential information may be hidden by rendering overlay layer 340 colored to make reversible data layer 320 invisible, or by overlay layer 340 preventing the confidential information from being identified. In addition, if the cover layer 340 is set to a temperature condition suitable for decoloring by heat generated by irradiating a laser beam, the developer and the leuco pigment are separated from each other, and the leuco pigment may be changed into a decolored state in a visible wavelength range. Accordingly, the visible image of the cover layer 340 is erased, the cover layer 340 becomes a decolored state, and the reversible data layer 320 becomes a visible state, so that the confidential information can be visibly recognized in the visible wavelength range. In addition, since a laser beam of a specific wavelength is necessary for the erasing process on the cover layer 340, a data protection seal 300 of a higher security level can be realized than the case where the visualization is simply performed by raising the temperature. That is, in the case where it is attempted to steal confidential information by a method other than the normal method, for example, it is attempted to heat the entire document 300 to bring the cover layer 340 into a decolored state, the confidential information written in the reversible data layer 3320 is also decolored at the same time, so that there is no risk that the confidential information is stolen.

In this embodiment, similar to the cover layer 340, the reversible data layer 320 contains a reversible material that switches between a colored state and a bleached state in the visible wavelength range. However, reversible data layer 320 includes a reversible material having a different switching condition than the switching condition of cover layer 340. That is, the capping layer 340 contains a reversible material that has a different switching condition than the reversible data layer 320. As a result, the drawing device 1 can perform the conversion between coloring and decoloring only on one of the reversible data layer 320 or the cover layer 340. Therefore, the drawing device 1 can control the visualization and the concealment of confidential information by merely switching between the coloring and the decoloring of the cover layer 340. Further, the drawing device 1 is also capable of performing rewriting on the reversible data layer 320.

Further, in the present embodiment, the thermal insulating adhesive layer 330 is disposed between the cover layer 340 and the reversible data layer 320; accordingly, the thermal insulation adhesive layer 330 prevents thermal propagation between the cover layer 340 and the reversible data layer 320. Therefore, for example, when color development or decoloration is performed on the cover layer 340, it is possible to prevent color development or decoloration from being performed on the reversible data layer 320 by mistake.

Further, in the present embodiment, the base layer 310 includes paper. This makes it possible to realize the document 300 having a high security level without impairing convenience as a printing medium (for example, capable of being printed on the base layer 310).

<4 > modification of the second embodiment

A modification of the document 300 according to the above-described embodiment will be described below.

[ modification F ]

In the second embodiment, in the case where the visible image data of the reversible data layer 320 is acquired by the image recognition unit 50, the information processing unit 70 may convert the processed image data obtained by performing predetermined processing on the visible image data read out from the storage unit 40 into image data to be written on the cover layer 340. The processed image data is, for example, grayscale image data having a pattern different from that of the visible image data of the reversible data layer 320. For example, the processed image data may be inverted image data in which the visible image data of the reversible data layer 320 is inverted as shown in fig. 18, or complex patterned image data as shown in fig. 19, for example. At this time, the light source unit 63 emits a laser beam so that the cover layer 340 has a reverse image of the visible image or an image different from the visible image by irradiation of the laser beam performed by the scanner unit 66. If the input image data for performing writing on the reversible data layer 320 is stored in the storage unit 40, the input image data may be used to generate processed image data instead of acquiring visible image data by the image recognition unit 50. That is, if writing on the reversible data layer 320 and writing on the cover layer 340 are performed by a single drawing device 1, or if input image data recorded in the reversible data layer 320 is easily referred to when writing is to be performed on the cover layer, the image recognition unit 50 may be omitted from the drawing device 1.

On the cover layer 340, if, for example, the reverse image data that inverts the visible image data as shown in fig. 18 is written, the confidential information is in a state of being visible through the cover layer 340 as a whole, but due to the cover layer 340, the confidential information appears as a visible image (for example, a solid image) different from the original visible image of the confidential information. Further, on the cover layer 340, if, for example, the complex patterned image data as shown in fig. 19 is written, a part of the confidential information is in a state of being visible through the cover layer 340, but due to the cover layer 340, the confidential information appears as a visible image (for example, a striped image) different from the original visible image of the confidential information. Therefore, by performing writing on the overcoat layer 340, confidential information can be hidden by the overcoat layer 340 as in the above-described embodiment. Instead, by performing an erase on overlay layer 340, confidential information may be visibly identified through overlay layer 340 as in the above-described embodiments.

[ modification G ]

In the second embodiment and its modifications, among the reversible data layer 320 and the cover layer 340, at least the cover layer 340 may contain, for example, a photochromic material. Examples of the photochromic material include diarylvinylene compounds and the like. The photochromic material is configured to switch between a colored state (colored state) and a bleached state in a visible wavelength range. The photochromic material has an absorption peak in an ultraviolet region in a decolored state, and when ultraviolet rays having a wavelength in the vicinity of the absorption peak are irradiated, the absorption peak shifts to a visible light region and changes to a colored state. Therefore, by irradiating ultraviolet rays having a wavelength in the vicinity of the absorption peak in the decolored state, the photochromic material is colored to make the confidential information invisible, or the cover layer 340 prevents the confidential information from being recognized, so that the confidential information can be concealed. In addition, by irradiating strong visible light near the absorption peak wavelength in a colored state to decolor the photochromic material and visualize the cover layer 340, confidential information can be visually recognized. Therefore, in the document 300 according to the present modification, the confidential information can also be visualized in the visible wavelength range.

[ modification example H ]

In the second embodiment and its modifications, among the reversible data layer 320 and the cover layer 340, at least the cover layer 340 may include, for example, a material configured to control light transmittance due to phase change in a visible wavelength range, or a material configured to switch between a color-developed state and a decolored state due to phase change in a visible wavelength range. As such a material, a phase change material configured to mutually convert between two phases of an amorphous phase and a crystalline phase may be used. For example, germanium-antimony-tellurium-alloys Ge₂Sb₂Te₅The film turned into a transparent amorphous phase when heated to an elevated temperature of about 600 ℃ and quenched, and turned into an opaque crystalline phase when heated to an intermediate temperature of about 160 ℃ and slowly cooled. By using such a phase change material for the capping layer 340, the amorphous phase may be a visible state of the confidential information, and the crystalline phase may be an invisible state of the confidential information. The confidential information may be hidden by changing the phase change material to a crystalline phase to make the cover layer 340 opaque, or by preventing the confidential information from being recognized by the cover layer 340. In addition, confidential information can be visually identified by changing the phase change material to an amorphous phase to make the cover layer 340 transparent. Therefore, in the document 300 according to the present modification, the confidential information can also be visualized in the visible wavelength range.

[ modification I ]

In the second embodiment and its variations, the document 300 may include one or more cover layers that function similarly to the cover layer 340, in addition to the cover layer 340. For example, as shown in FIG. 20, the document 300 may further include a thermally insulating adhesive layer 350 and a cover layer 360 on the back side of the base layer 310 (i.e., the opposite side of the cover layer 340 in positional relationship with the reversible data layer 320). The adiabatic adhesive layer 350 and the cover layer 360 are stacked in this order from the rear surface of the base layer 310. The thermal barrier adhesive layer 350 is a layer of a pressure sensitive adhesive or an adhesive for attaching the cover layer 360 to the back surface of the base layer 310, and is a layer capable of preventing heat from being transmitted between the cover layer 340 and the cover layer 360. The adiabatic adhesive layer 350 includes, for example, a pressure-sensitive adhesive or an adhesive containing a synthetic resin having a thermal conductivity of 0.3(W/m · K) or less. The thickness of the thermal barrier adhesive layer 350 is desirably 3 μm or more, and more desirably 6 μm or more.

The cover layer 360 is a layer for hiding confidential information, which is visible through the base layer 310 in the case where the base layer 310 includes a light-transmitting material. The cover layer 360 is configured to switch between a colored state and a bleached state in the visible wavelength range. In this case, the optical density of the color at which the overlay layer 360 develops color may be a density at which the visible image of the reversible data layer 320 cannot be visibly recognized. The visible image of overlay layer 360 may include multiple colors or may include a single color. In case the visible image of the reversible data layer 320 comprises a single color, the color difference Δ E between the reversible data layer 320 and the cover layer 360 is preferably 1.2 or less. It should be noted that the color difference Δ E between the reversible data layer 320 and the overlay layer 360 may be such that a visible image of the reversible data layer 320 may not be visually recognizable.

When the cover layer 360 is in a colored state in the visible wavelength range, the cover layer 360 prevents confidential information from being visually recognized or identified. In the case where the overlay layer 360 prevents the confidential information from being visibly recognized, a part or all of the confidential information is made invisible by the overlay layer 360. In contrast, in the case where the cover layer 360 prevents the confidential information from being recognized, a part or all of the confidential information may be in a state of being visible through the cover layer 360, but the confidential information appears as a visible image different from the original visible image of the confidential information due to the cover layer 360.

Further, when the cover layer 360 is in a decolored state in visible wavelengths, the cover layer 360 cannot prevent confidential information from being visually recognized. At this point, the confidential information is in a state of being visible through the overlay layer 360.

The cover layer 360 includes, for example, a leuco pigment and a photothermal conversion agent for generating heat at the time of writing. The cover 360 also contains, for example, a developer and a polymer.

The leuco pigment is combined with the developer to become a colored state in the visible wavelength range, or is separated from the developer to become a decolored state in the visible wavelength range. When the cover layer 360 reaches its writing temperature by heat, the leuco pigment contained in the cover layer 360 is combined with a developer and develops a predetermined color in a visible wavelength range. Further, the cover layer 360 is transparent in a decolored state in a visible wavelength range. The photothermal conversion agent absorbs light in, for example, the near infrared region (700nm to 2500nm), and generates heat. For example, the photothermal conversion agent contained in the cover layer 360 has an absorption peak at a wavelength λ 3(λ 3 ≠ λ 1, λ 2, 700nm ≦ λ 3 ≦ 2500 nm). That is, the cover layer 360 includes a reversible material having a different switching condition than the reversible data layer 320 and the cover layer 340. In the present modification, in the case where the cover layer 360 is provided below the reversible data layer 320 and the cover layer 340, it is preferable that the wavelength λ 3 of the absorption peak of the photothermal conversion agent included in the cover layer 360 be longer than the wavelengths λ 1 and λ 2 of the absorption peaks of the photothermal conversion agent included in the reversible data layer 320 and the cover layer 340. This is to make it difficult for the reversible data layer 320 and the cover layer 340 to absorb a laser beam having a wavelength λ 3, for example, when writing or erasing is performed on the cover layer 360 via the reversible data layer 320 and the cover layer 340 by using the drawing device 1 including the drawing unit 60 of fig. 21, which will be described later.

Next, the drawing unit 60 that performs writing and erasing on the document 300 including the reversible data layer 320, the cover layer 340, and the cover layer 360 as shown in fig. 20 will be described. Fig. 21 shows a schematic configuration example of the drawing unit 60 that performs writing and erasing on the document 300 shown in fig. 20. The drawing unit 60 includes, for example, a signal processing circuit 61, a laser driving circuit 62, a light source unit 63, an adjustment mechanism 64, a scanner driving circuit 65, and a scanner unit 66. The drawing unit 60 controls the output of the light source unit 63 based on the output set value input from the information processing unit 70, thereby performing drawing at the temperature 300.

The signal processing circuit 61 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates, for example, a pixel signal Dout corresponding to a scanner operation of the scanner unit 66 from the image signal Din. The pixel signal Dout causes the light source unit 63 (for example, light sources 63A, 63B, and 63C described later) to output a laser beam having a power corresponding to an output set value. The signal processing circuit 61 controls the peak value of the current pulse to be applied to the light source unit 63 (for example, the light sources 63A, 63B, and 63C) in accordance with the signal Dout together with the laser driving circuit 62.

The laser drive circuit 62 drives each of the light sources 63A, 63B, and 63C of the light source unit 63, for example, in accordance with the pixel signal Dout. The laser drive circuit 62 controls, for example, the luminance (luminance) of a laser beam for drawing an image corresponding to the pixel signal Dout. The laser drive circuit 62 includes, for example, a drive circuit 62A that drives the light source 63A, a drive circuit 62B that drives the light source 63B, and a drive circuit 62C that drives the light source 63C. The light sources 63A, 63B, and 63C each perform writing and erasing on the document 300 by outputting a laser beam of power corresponding to the output setting value to the document 300. The light sources 63A, 63B, and 63C each emit a laser beam in the near infrared region. The light source 63A is, for example, a laser diode that emits a laser beam La having a wavelength λ 1. The light source 63B is, for example, a laser diode that emits a laser beam Lb having a wavelength λ 2. The light source 63C is, for example, a laser diode that emits a laser beam Lc having a wavelength λ 3.

The light source unit 63 has a plurality of light sources that emit light of different wavelengths in the near infrared region. The light source unit 63 includes, for example, three light sources 63A, 63B, and 63C. The light source unit 63 further includes, for example, an optical system that synthesizes laser beams emitted from a plurality of light sources (for example, three light sources 63A, 63B, and 63C). As such an optical system, the light source unit 63 includes, for example, a mirror 63a, a dichroic mirror 63b, and a lens 63 e.

For example, each of the laser beams La and Lb emitted from the two light sources 63A and 63B is converted into substantially parallel light (collimated light) by the collimator lens. Then, for example, the laser beam La is reflected by the reflecting mirror 63a and further reflected by the dichroic mirror 63b, and the laser beam Lb passes through the dichroic mirror 63b, whereby the laser beam La and the laser beam Lb are synthesized together. The laser beam La and the combined light of the laser beam La are transmitted through the dichroic mirror 63 c.

The laser beam Lc emitted from the light source 63C is converted into substantially parallel light (collimated light) by a collimator lens. Then, for example, the laser beam Lc is reflected by the mirror 63d, and further reflected by the dichroic mirror 63 c. Therefore, the synthesized light transmitted through the dichroic mirror 63c and the laser beam Lc reflected by the dichroic mirror 63c are synthesized together. The light source unit 63 outputs, for example, synthesized light Lm obtained by synthesis by an optical system to the scanner unit 66.

The scanner drive circuit 65 drives the scanner unit 66 in synchronization with, for example, a projection image clock signal input from the signal processing circuit 61. Further, in the case where a signal of an irradiation angle of a biaxial scanner 66A described later or the like is input from the scanner unit 66, the scanner drive circuit 65 drives the scanner unit 66 based on the signal so that the irradiation angle becomes a desired irradiation angle.

The scanner unit 66, for example, raster scans the surface of the document 300 with the synthesized light Lm output from the light source unit 63. The scanner unit 66 includes, for example, a biaxial scanner 66A and an f θ lens 66B. The two-axis scanner 66A is, for example, a galvanometer mirror. The f θ lens 66B converts the constant speed scanning of the dual axis scanner 66A into a constant speed linear scanning of the spot moving on the focal plane (the surface of the document 300). It should be noted that the scanner unit 66 may include a single axis scanner and an f θ lens. In this case, it is preferable to provide a single-axis stage for moving the document 300 in a direction perpendicular to the scanning direction of the single-axis scanner.

Next, an example of performing writing on the reversible data layer 230, the cover layer 340, and the cover layer 360 by the drawing system 1 will be described.

[ writing ]

First, the user prepares the uncolored reversible data layer 230, the overlay layer 340, and the overlay layer 360 and sets them in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform writing through the input unit 20. Then, the information processing unit 70 converts the three pieces of image data read out from the storage unit 40 into the output setting values of the drawing unit 60 for performing writing on the reversible data layer 230, the cover layer 340, and the cover layer 360, and inputs the three output setting values obtained by the conversion to the drawing unit 60. The drawing unit 60 performs writing on the reversible data layer 230, the cover layer 340, and the cover layer 360 based on the three input output setting values.

The drive circuit 62A drives the light source 63A of the light source unit 63 in accordance with the light emission signal generated from the first output setting value. The drive circuit 62B drives the light source 63B of the light source unit 63 in accordance with the light emission signal generated from the second output setting value. The drive circuit 62C drives the light source 63C of the light source unit 63 in accordance with the light emission signal generated from the third output setting value. At this time, the driving circuit 62A causes the laser beam La to be emitted from the light source 63A, the driving circuit 62B causes the laser beam Lb to be emitted from the light source 63B, the driving circuit 62C causes the laser beam Lc to be emitted from the light source 63C, and the synthesized light Lm thereof is scanned over the document 300. As a result, the laser beam La of the wavelength λ 1 included in the synthesized light Lm is absorbed by the photo-thermal converter in the reversible data layer 230, so that the reversible data layer 230 is brought to the writing temperature by the heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in the visible wavelength range (upper diagram of fig. 22). Further, the laser beam Lb having the wavelength λ 2 included in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 340, so that the cover layer 340 is brought to a writing temperature by heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in a visible wavelength range (middle diagram of fig. 22). Further, the laser beam Lc having the wavelength λ 3 contained in the synthesized light Lm is absorbed by the photo-thermal converter in the cover layer 360, so that the cover layer 360 is brought to a writing temperature by heat generated by the photo-thermal converter, and the leuco pigment is combined with the developer to develop a predetermined color in a visible wavelength range (the lower diagram of fig. 22). Thus, the drawing unit 60 performs writing on the document 300 shown in fig. 20.

Next, an example of performing erasing on the reversible data layer 230, the cover layer 340, and the cover layer 360 by the drawing device 1 will be described.

[ Erase ]

First, the user prepares the reversible data layer 230, the cover layer 340, and the cover layer 360 on which writing has been performed as described above, and sets them in the drawing unit 60. Then, the user instructs the information processing unit 70 to perform erasing on the cover layers 340 and 360 through the input unit 20. Then, the information processing unit 70 sets the output setting value so that the temperature of the cover layers 340, 360 on which the erasing is to be performed satisfies the temperature condition suitable for the decoloring with the heat generated by the photothermal conversion agent. The drawing unit 60 performs erasing on the over-layers 340 and 360 based on the inputted output setting value.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

The laser drive circuit 62 drives the light sources 63B and 63C of the light source unit 63 according to the light emission signal. At this time, the laser drive circuit 62 causes the laser beams Lb and Lc to be emitted from the light source 63B, and causes the laser beams Lb and Lc to scan over, for example, the document 300. As a result, the laser beam Lb is absorbed by the photothermal converter in the covering layer 340, so that the covering layer 340 is brought to a temperature condition suitable for decoloring by the heat generated by the photothermal converter, and the leuco pigment is separated from the developer and decolored (upper diagram of fig. 23). Further, the laser beam Lc is absorbed by the photothermal conversion agent in the cover layer 360, so that the cover layer 360 is brought to a temperature condition suitable for decoloring by the heat generated by the photothermal conversion agent, and the leuco pigment is separated from the developer and decolored (middle panel of fig. 23). Thus, drawing unit 60 performs erasing on capping layers 340 and 360.

The signal processing circuit 61 of the drawing unit 60 acquires the output setting value input from the information processing unit 70 as the image signal Din. The signal processing circuit 61 generates a light emission signal in synchronization with the scanning operation of the scanner unit 66 and in accordance with the characteristics of the laser beam such as the wavelength, based on the image signal Din, and outputs the generated light emission signal to the laser driving circuit 62 of the drawing unit 60.

[ Effect ]

Next, effects of the document 300 and the drawing device 1 according to the present modification will be described.

In the document 300 according to the present modification, confidential information may be hidden by making the overlay layers 340 and 360 appear color to make the confidential information invisible, or allowing the overlay layers 340 and 360 to prevent the confidential information from being recognized. In addition, by decoloring the cover layers 340, 360 and visualizing the confidential information, the confidential information can be visually recognized in the visible wavelength range. Therefore, in the document 300 according to the present modification, the confidential information can be visualized in the visible wavelength range.

Further, in the present modification, the cover layers 340 and 360 each include a leuco pigment, a light-heat converter, a developer, and a polymer. Therefore, by irradiating the covering layers 340 and 360 with a laser beam having a light emission wavelength corresponding to the absorption wavelength of the photothermal conversion agent, and by heating the photothermal conversion agent, the covering layers 340 and 360 each reach a writing temperature, the developer and the leuco pigment are bonded to each other, and it becomes possible to change the leuco pigment to a color developed state in the visible wavelength range. Thus, confidential information may be hidden by rendering each of overlays 340 and 360 colored to make reversible data layer 320 invisible, or by protecting confidential information from being recognized by overlays 340 and 360. In addition, if the covering layers 340 and 360 are each set to a temperature condition suitable for decoloring by heat generated by irradiating a laser beam, the developer and the leuco pigment are separated from each other, and the leuco pigment may be brought into a decolored state in a visible wavelength range. Accordingly, the visible image of each of the cover layers 340 and 360 is erased, the cover layers 340 and 360 become the decolored state, respectively, and the reversible data layer 320 becomes the visible state, so that the confidential information can be visibly recognized in the visible wavelength range. In addition, since a laser beam of a specific wavelength is necessary for the erasing process on the cover layers 340 and 360, a document 300 of a higher security level can be realized than the case where the visualization is simply performed by raising the temperature. That is, in the case where it is attempted to steal confidential information by a method other than the normal method, for example, it is attempted to heat the entire document 300 to bring the cover layers 340 and 360 into the decolored state, the confidential information written in the reversible data layer 320 is also decolored at the same time, so that there is no risk that the confidential information is stolen.

In this variation, similar to cover layers 340 and 360, reversible data layer 320 contains a reversible material configured to switch between a colored state and a bleached state in the visible wavelength range. However, the drawing device 1 is configured to perform conversion between coloring and decoloring only on one of the reversible data layer 320 or the cover layers 340 and 360. Therefore, the drawing device 1 can control the visualization and the concealment of confidential information by merely switching between the coloring and the decoloring of the cover layers 340 and 360. Further, the drawing device 1 is also capable of performing rewriting on the reversible data layer 320.

In the present modification, the cover layers 340 and 360 are provided to sandwich the base layer 310 and the reversible data layer 320 from above and below. As a result, even in the case where the base layer 310 contains a resin material that is transparent in the visible region or a material that allows confidential information to be seen perspectively in the visible region, the cover layers 340 and 360 can control visualization and concealment of confidential information.

[ modification J ]

In the above-described modification I, in the case where the image recognition unit 50 acquires the visible image data of the reversible data layer 320, the information processing unit 70 may convert the first processed image data obtained by performing predetermined processing on the visible image data read out from the storage unit 40 into image data to be drawn on the cover layer 340, and may also convert the second processed image data obtained by performing predetermined processing on the visible image data read out from the storage unit 40 into image data to be drawn on the cover layer 360. At this time, as shown in fig. 24 and 25, for example, the information processing unit 70 generates the first processed image data and the second processed image data such that the pattern Ic obtained by superimposing the pattern Ia of the first processed image data and the pattern Ib of the second processed image data on each other is a pattern different from the pattern Id of the visible image data of the reversible data layer 320. It should be noted that in fig. 25, the pattern Ic and the pattern Id are visually distinguishable, but this is for illustrative purposes only, and in reality, it is difficult to visually distinguish the pattern Ic and the pattern Id.

It is to be noted that the pattern Ic may be a pattern obtained by inverting the pattern Id, for example, as shown in fig. 25, or may be a complex stripe pattern, for example, as shown in fig. 26. At this time, the light source unit 63 emits a laser beam so that the laser beam is irradiated through the scanner unit 66, and the cover layers 340 and 360 each become a reverse image of the visible image or an image different from the visible image. In the case where the pattern Ic is a pattern obtained by inverting the pattern Id, it is difficult to visually distinguish the pattern Ic and the pattern Id; therefore, even if the measurement is performed by the means for measuring the transmittance and by visual inspection, the transmittance is constant regardless of which part is measured, so that confidential information can be effectively hidden. Further, in the case where the pattern Ic is a complicated stripe pattern, it is difficult to recognize confidential information by visual inspection; therefore, confidential information can be effectively hidden.

[ modification K ]

In the second embodiment and its variations, the document 300 may include a data layer 370, instead of the reversible data layer 320, on which confidential information is recorded as a visible image. The data layer 370 is, for example, a printed layer in which confidential information is irreversibly fixed on the base layer 310 and includes a visible image formed, for example, by offset printing. It should be noted that the data layer 370 may be characters or pictures handwritten on the base layer 310. Data layer 370 includes visible images such as numbers, letters, bar codes, two-dimensional codes, photographs, and graphics. At this time, the optical density of the color when the cover layer 340 is colored may be a density at which the visible image of the data layer 370 cannot be visually recognized. The visible image of the overlay layer 340 may include multiple colors or may include a single color. In case the visible image of the data layer 370 comprises a single color, the color difference Δ E between the data layer 370 and the overlay layer 340 is preferably 1.2 or less. It should be noted that the color difference Δ E between data layer 370 and overlay layer 340 may not make a visible image of data layer 370 visually recognizable.

Even in this case, confidential information can be hidden by making overlay layer 340 appear colored so that data layer 370 is invisible, or by preventing confidential information from being recognized by overlay layer 340. Further, by changing the cover layer 340 to a decolored state and visualizing the data layer 370, confidential information can be visually recognized in the visible wavelength range. Therefore, the document 300 according to the present modification can visualize confidential information in the visible wavelength range.

<5. third embodiment >

[ arrangement ]

A card 400 according to a third embodiment of the present disclosure will be described. Fig. 28 shows a schematic configuration example of the card 400 according to the present embodiment. Card 400 includes, for example: a base layer 410; and a reversible data layer 420, a thermal insulating adhesive layer 430, and a cover layer 440 formed on the base layer 410. The reversible data layer 420, the adiabatic adhesive layer 430, and the cover layer 440 are stacked on the base layer 410 in this order. The positions of the reversible data layer 420 and the overlay layer 440 may be swapped. A thermally insulating adhesive layer 430 and a cover layer 440 are disposed opposite the reversible data layer 420.

For example, the base material layer 410 includes an opaque resin material. The thermal insulating adhesive layer 430 is a layer for attaching the cover layer 440 to the reversible data layer 420, and is a layer capable of preventing heat from being transmitted between the cover layer 440 and the reversible data layer 420. The heat-insulating adhesive layer 430 includes, for example, a pressure-sensitive adhesive or an adhesive containing a synthetic resin having a thermal conductivity of 0.3(W/m · K) or less. The thickness of the adiabatic adhesive layer 330 is desirably 3 μm or more, and more desirably 6 μm or more.

The reversible data layer 420 and the cover layer 440 are each configured to switch between a colored state and a bleached state in the visible wavelength range. The cover layer 440 comprises a reversible material having a switching condition that is different from the switching condition of the reversible data layer 420. That is, reversible data layer 420 includes a reversible material having a different switching condition than the switching condition of cover layer 440. At this time, the optical density of the color when the cover layer 440 is colored may be a density at which the visible image of the reversible data layer 420 cannot be visually recognized. The visible image of overlay layer 440 may comprise multiple colors or may comprise a single color. In the case of a visible image of the reversible data layer 420, the color difference Δ E between the reversible data layer 420 and the cover layer 440 is preferably 1.2 or less. It should be noted that the color difference Δ E between the reversible data layer 420 and the overlay layer 440 may make the visible image of the reversible data layer 420 visually unrecognizable.

Overlay layer 440 is a layer used to hide confidential information written on reversible data layer 420. When the cover layer 440 is in a colored state in the visible wavelength range, the cover layer 440 prevents confidential information from being visually recognized or identified. In the case where the overlay layer 440 prevents the confidential information from being visibly recognized, a part or all of the confidential information is made invisible by the overlay layer 440. In contrast, in the case where the cover layer 440 prevents the confidential information from being recognized, a part or all of the confidential information may be in a state of being visible through the cover layer 440, but the confidential information appears as a visible image different from the original visible image of the confidential information due to the cover layer 440.

Further, when the cover layer 440 is in a decolored state in visible wavelengths, the cover layer 440 cannot prevent confidential information from being visibly recognized. At this time, the confidential information is in a state of being visible through the cover layer 440.

The reversible data layer 420 includes, for example, a leuco pigment and a light-to-heat conversion agent for generating heat at the time of writing. Reversible data layer 420 also includes, for example, a developer and a polymer.

The cover layer 440 includes, for example, a leuco pigment and a light-heat conversion agent for generating heat at the time of writing. The cover layer 440 also includes, for example, a developer and a polymer.

The leuco pigment is combined with the developer to become a colored state in the visible wavelength range, or is separated from the developer to become a decolored state in the visible wavelength range. When the cover layer 440 reaches its writing temperature by heating, the leuco pigment included in the cover layer 440 is combined with a developer and develops a predetermined color in a visible wavelength range. Further, the cover layer 440 is transparent in a decolored state in a visible wavelength range. The photothermal conversion agent absorbs light in, for example, the near infrared region (700nm to 2500nm), and generates heat. For example, the photothermal conversion agent included in the cover layer 440 has an absorption peak at a wavelength λ 2(λ 2 ≠ λ 1, 700nm ≦ λ 2 ≦ 2500 nm). In the present embodiment, in the case where reversible data layer 420 is disposed below cover layer 440, wavelength λ 1 of the absorption peak of the light-to-heat converter included in reversible data layer 420 is preferably longer than wavelength λ 2 of the absorption peak of the light-to-heat converter included in cover layer 440. This is to make it difficult for the cover layer 440 to absorb a laser beam having a wavelength λ 1, for example, when writing or erasing is performed on the reversible data layer 420 via the cover layer 440 by using the drawing device 1 including the drawing unit 60 of fig. 9. Further, in the present embodiment, in the case where the cover layer 440 is disposed below the reversible data layer 420, the wavelength λ 2 of the absorption peak of the photothermal conversion agent included in the cover layer 440 is preferably longer than the wavelength λ 1 of the absorption peak of the photothermal conversion agent included in the reversible data layer 420. This is for making it difficult for the reversible data layer 420 to absorb a laser beam having a wavelength λ 2, for example, when writing or erasing is performed on the cover layer 440 via the reversible data layer 420 by using the drawing device 1 including the drawing unit 60 of fig. 9.

Writing and erasing on the reversible data layer 420 and the cover layer 440 may be performed in a similar manner to writing and erasing performed on the reversible data layer 320 and the cover layer 340 according to the second embodiment.

[ Effect ]

Next, the effects of the card 400 according to the present embodiment will be described.

In the card 400 according to the present embodiment, the cover layer 440 may be colored to make the confidential information invisible, or to allow the cover layer 440 to prevent the confidential information from being recognized. In addition, by decoloring the cover layer 440 and visualizing the confidential information, the confidential information can be visually recognized in the visible wavelength range. Therefore, in the card 400 according to the present modification, the confidential information can be visualized in the visible wavelength range.

Further, in the present embodiment, the cover layer 440 includes a leuco pigment, a light-heat converter, a developer, and a polymer. Therefore, by irradiating the cover layer 440 with a laser beam having a light emission wavelength corresponding to the absorption wavelength of the photothermal conversion agent, and by heating the photothermal conversion agent, the cover layer 440 reaches the writing temperature, the developer and the leuco pigment are bonded to each other, and it becomes possible to change the leuco pigment into a color developed state in the visible wavelength range. Thus, confidential information may be hidden by rendering overlay layer 440 colored to make reversible data layer 420 invisible, or by overlay layer 440 preventing the confidential information from being identified. In addition, if the cover layer 440 is set to a temperature condition suitable for decoloring by heat generated by irradiating a laser beam, the developer and the leuco pigment are separated from each other, and the leuco pigment may be changed into a decolored state in a visible wavelength range. Accordingly, the visible image of the cover layer 440 is erased, the cover layer 440 becomes a decolored state, and the reversible data layer 420 becomes a visible state, so that the confidential information can be visibly recognized in the visible wavelength range. In addition, since a laser beam of a specific wavelength is necessary for the erasing process on the cover layer 440, the card 400 of higher security level can be realized as compared with the case where the visualization is simply performed by raising the temperature. That is, in the case where it is attempted to steal the confidential information by a method other than the normal method, for example, it is attempted to heat the card 400 to bring the cover layer 440 into the decolored state, the confidential information written in the reversible data layer 420 is also decolored at the same time, so that there is no risk that the confidential information is stolen.

In the present embodiment, the reversible data layer 420, similar to the cover layer 440, includes a reversible material configured to switch between a colored state and a bleached state in the visible wavelength range. However, reversible data layer 420 includes a reversible material having a different switching condition than the switching condition of cover layer 440. That is, the cover layer 440 includes a reversible material having a different switching condition than the reversible data layer 420. As a result, the drawing device 1 can perform the conversion between coloring and decoloring only on one of the reversible data layer 420 or the cover layer 440. Therefore, the drawing device 1 can control the visualization and the concealment of confidential information by merely switching between the coloring and the decoloring of the cover layer 440. Further, the drawing device 1 is also capable of performing rewriting on the reversible data layer 420.

Further, in the present embodiment, the adiabatic adhesive layer 430 is disposed between the cover layer 440 and the reversible data layer 420; thus, the thermal barrier adhesive layer 430 prevents heat from propagating between the cover layer 440 and the reversible data layer 420. Thus, for example, when coloring or decoloring is performed on the cover layer 440, it is possible to prevent coloring or decoloring from being erroneously performed on the reversible data layer 420.

In the present embodiment, the card 400 may have a configuration similar to the modifications F, G, H, I and J. Further, in the present embodiment, for example, as shown in fig. 29, a data layer 450 on which confidential information is recorded as a visible image may be included instead of the reversible data layer 420. The data layer 450 is a printed layer in which confidential information is irreversibly fixed on the base layer 410, and includes a visible image formed by, for example, offset printing. It should be noted that the data layer 450 may be characters or pictures handwritten on the base layer 410. The data layer 450 includes visible images such as numbers, letters, bar codes, two-dimensional codes, photographs, and graphics. Even in this case, the confidential information may be hidden by making the cover layer 440 appear colored so that the reversible data layer 420 is invisible, or by preventing the confidential information from being recognized by the cover layer 440. By changing the cover layer 440 to a bleached state and visualizing the reversible data layer 420, confidential information may be visibly identified in the visible wavelength range. Therefore, even in this case, the document 300 can visualize confidential information in the visible wavelength range.

<7 > common modification of each embodiment

[ modification M ]

In the first embodiment and its variants, the data protective seal 100 may include a pair of water vapor barrier layers 160 sandwiching the cover layer 110, for example, from above and below, as shown in fig. 30. Either one of the pair of water vapor barrier layers 160 may be omitted as necessary. The water vapor barrier layer 160 protects the cover layer 110, for example, having a thickness of 0.1g/m²Water vapor permeability per day or less. As described above, by providing the water vapor barrier layer 160, natural discoloration of the cover layer 110 can be suppressed even under a severe environment, and confidential information can be maintained in a confidential state for a long period of time.

Further, in the first embodiment and its modifications, the data protection seal 100 may include, for example, a pair of ultraviolet blocking layers 170 sandwiching the cover layer 110 from above and below, as shown in fig. 31. The ultraviolet blocking layer 170 protects the capping layer 110 and has a light transmittance of, for example, 70% or less of light having a wavelength shorter than 420 nm. Any one of the pair of ultraviolet blocking layers 170 may be omitted as necessary. As described above, by providing the ultraviolet blocking layer 170, natural discoloration of the cover layer 110 can be suppressed even under severe environments, and confidential information can be maintained in a confidential state for a long period of time.

Further, in the first embodiment and its modifications, the data protection seal 100 may include a pair of water vapor barrier layers 160 sandwiching the cover layer 110 in the vertical direction, and a pair of ultraviolet ray barrier layers 170 sandwiching the cover layer 110 in the vertical direction, as shown in fig. 32, for example. Either one of the pair of water vapor barrier layers 160 may be omitted as necessary. Any one of the pair of ultraviolet blocking layers 170 may be omitted as necessary. As described above, by providing the water vapor barrier layer 160 or the ultraviolet barrier layer 170, natural discoloration of the cover layer 110 can be suppressed even under a severe environment, and confidential information can be maintained in a confidential state for a long period of time.

[ modification N ]

In the second embodiment and its modifications, the document 300 may include, for example, a pair of water vapor barrier layers 380 sandwiching the cover layer 340 from above and below, as shown in fig. 33. Either one of the pair of water vapor barrier layers 380 may be omitted as necessary. The water vapor barrier layer 380 protects the cover layer 340, e.g. having a thickness of 0.1g/m²Water vapor permeability per day or less. As described above, by providing the water vapor barrier layer 380, natural discoloration of the cover layer 340 can be suppressed even under severe environments, and confidential information can be maintained in a confidential state for a long period of time.

Further, in the second embodiment and its modifications, the document 300 may include, for example, a pair of ultraviolet blocking layers 390 sandwiching the cover layer 340 from above and below, as shown in fig. 34. The ultraviolet blocking layer 390 protects the capping layer 340 and has a light transmittance of, for example, 70% or less of light having a wavelength shorter than 420 nm. Any one of the pair of ultraviolet blocking layers 390 may be omitted as necessary. As described above, by providing the ultraviolet blocking layer 390, natural discoloration of the cover layer 340 can be suppressed even under severe environments, and confidential information can be maintained in a confidential state for a long period of time.

Further, in the second embodiment and its modifications, the document 300 may include, for example, as shown in fig. 35, a pair of water vapor barrier layers 380 sandwiching the cover layer 340 in the vertical direction, and a pair of ultraviolet ray barrier layers 390 sandwiching the cover layer 340 in the vertical direction. Either one of the pair of water vapor barrier layers 380 may be omitted as necessary. Any one of the pair of ultraviolet blocking layers 390 may be omitted as necessary. As described above, by providing the water vapor barrier layer 380 or the ultraviolet ray barrier layer 390, natural discoloration of the cover layer 340 can be suppressed even under a severe environment, and confidential information can be maintained in a confidential state for a long period of time.

[ modification O ]

In the third embodiment and its modifications, the card 400 may include a pair of water vapor barrier layers 460 sandwiching the cover layer 440 from above and below, for example, as shown in fig. 36. Any one of the pair of water vapor barrier layers 460 may be omitted as needed. The water vapor barrier layer 460 protects the cover layer 440 and has, for example, 0.1g/m²Water vapor permeability per day or less. As described above, by providing the water vapor barrier layer 460, natural discoloration of the cover layer 440 can be suppressed even under a severe environment, and confidential information can be kept in a confidential state for a long period of time.

Further, in the third embodiment and its modifications, the card 400 may include a pair of ultraviolet blocking layers 470 sandwiching the cover layer 440 from above and below, for example, as shown in fig. 37. The ultraviolet blocking layer 470 protects the capping layer 440 and has a light transmittance of, for example, 70% or less of light having a wavelength shorter than 420 nm. Any one of the pair of ultraviolet blocking layers 470 may be omitted as necessary. As described above, by providing the ultraviolet blocking layer 470, natural discoloration of the cover layer 440 can be suppressed even under severe environments, and confidential information can be maintained in a confidential state for a long period of time.

Further, in the third embodiment and its modifications, the card 400 may include a pair of water vapor barrier layers 460 sandwiching the cover layer 440 in the vertical direction and a pair of ultraviolet ray barrier layers 470 sandwiching the cover layer 440 in the vertical direction, as shown in fig. 38, for example. Any one of the pair of water vapor barrier layers 460 may be omitted as needed. Any one of the pair of ultraviolet blocking layers 470 may be omitted as necessary. As described above, by providing the water vapor barrier layer 460 or the ultraviolet barrier layer 470, natural discoloration of the cover layer 440 can be suppressed even under severe environments, and confidential information can be maintained in a confidential state for a long period of time.

In modifications M to O, only the cover layer is sandwiched between at least one of the water vapor barrier layer or the ultraviolet ray barrier layer. However, in the modifications M to O, it is more preferable that both the cover layer and the reversible data layer are sandwiched between at least one of the water vapor barrier layer or the ultraviolet ray barrier layer. This is because natural decoloration of the reversible data layer can be suppressed even under a severe environment, and confidential information can be kept in a confidential state for a long period of time.

Although the present disclosure has been described above with reference to exemplary embodiments and modifications, these embodiments and modifications should not be construed as limiting the scope of the present disclosure, and may be modified in various ways.

It should be understood that the effects described herein are merely examples. Effects of the example embodiments and the modifications of the present disclosure are not limited to those described herein. The present disclosure may also include any effect other than those described herein.

Further, the present disclosure may have the following configuration.

(1)

A data protector, comprising:

a data layer configured to record the confidential information as a visible image; and

one or more cover layers disposed at least one of above or below the data layer and configured to switch between a colored state and a decolored state in a visible wavelength range.

(2)

The data protector according to (1), wherein,

the data layer is configured to switch between a colored state and a bleached state in the visible wavelength range and contains a reversible material having a switching condition different from the switching condition of the one or more cover layers, an

The confidential information is recorded as a visible image on the data layer by the development of the reversible material.

(3)

The data protector of (1) or (2), wherein the one or more cover layers contain a leuco pigment.

(4)

The data protector of (1) or (2), wherein the one or more cover layers comprise a photochromic material.

(5)

The data protector according to (1) or (2), wherein the one or more cover layers contain a material configured to be capable of controlling light transmittance by phase change in a visible wavelength range, or a material configured to be capable of switching a colored state and a decolored state by phase change in a visible wavelength range.

(6)

The data protector of any of (1) through (5), wherein the one or more overlay layers contain a grayscale image of a pattern different from a pattern of the visible image.

(7)

The data protector of any of (1) through (6), further comprising one or more water vapor barrier layers protecting the one or more cover layers and having 0.1g/m²Water vapor permeability below day.

(8)

The data protector of any one of (1) to (7), further comprising one or more ultraviolet blocking layers that protect the one or more cover layers and have a light transmittance of 70% or less for light having a wavelength shorter than 420 nm.

(9)

The data protector of any one of (1) through (8), further having a thermal insulating layer between the one or more cover layers and the data layer.

(10)

The data protector of any one of (1) to (9), further having a substrate supporting the data layer, wherein,

the substrate is made of paper.

(11)

The data protector of any one of (1) to (9), further having a substrate supporting the data layer, wherein,

the base material is made of synthetic resin.

(12)

A data protector, comprising:

a data layer that records the confidential information as a visible image; and

one or more cover layers disposed at least one of above or below the data layer and configured to switch between a colored state and a bleached state in a visible wavelength range.

(13)

The data protector of (12), wherein the data layer is a printed layer in which confidential information is irreversibly fixed on the base material.

(14)

A data protection seal for protecting a data layer configured to record confidential information as a visible image, the data protection seal comprising:

one or more cover layers configured to be capable of switching a colored state and a decolored state in a visible wavelength range; and

an adhesive layer disposed at a position facing the one or more cover layers.

(15)

The data protective seal of (14), wherein the one or more cover layers comprise a reversible material having a switching condition different from a switching condition of the data layer.

(16)

The data protective seal according to (14) or (15), further comprising a protective layer for protecting the adhesive layer.

(17)

A data protection seal that protects a data layer that records confidential information as a visible image, the data protection seal comprising:

one or more cover layers configured to switch between a colored state and a bleached state in a visible wavelength range; and

an adhesive layer disposed at a position facing the one or more cover layers.

(18)

The data protective seal according to (17), further comprising a protective layer for protecting the adhesive layer.

(19)

A drawing device that performs at least one of writing or erasing on a data layer and one or more cover layers of a data protector including the data layer and the one or more cover layers on which confidential information is recorded as a visible image, the data layer containing a first reversible material configured to switch between a colored state and a decolored state in a visible wavelength range, the one or more cover layers containing a second reversible material configured to switch between a colored state and a decolored state in a visible wavelength range and being disposed at least one of above or below the data layer, the drawing device comprising:

a light source unit that emits a laser beam, which is at least one of a first laser beam having a condition under which no color development and decoloring reaction of the first reversible material occurs and any one reaction of color development and decoloring of the second reversible material occurs, or a second laser beam having a condition under which no color development and decoloring reaction of the second reversible material occurs and any one reaction of color development and decoloring of the first reversible material occurs; and

an optical unit performing at least one of writing or erasing on the data layer or the one or more cover layers by irradiating the data layer or the one or more cover layers with a laser beam emitted from the light source unit.

(20)

The drawing device according to (19), wherein the light source unit emits a laser beam so that the one or more cover layers have a reverse image of the visible image or an image different from the visible image by the laser beam irradiation performed by the optical unit.

According to the first and second data protectors of the embodiment of the present disclosure, the confidential information may be hidden by changing the one or more cover layers to the colored state to change the data layer to the invisible state, or by preventing the confidential information from being recognized by the cover layers, and the confidential information may be visibly recognized in the visible wavelength range by changing the one or more cover layers to the decolored state to change the data layer to the visible state; thus, confidential information can be visualized in the visible wavelength range.

According to the first and second data protection seals of the embodiment of the present disclosure, for example, the confidential information may be hidden by attaching the first and second data protection seals to the data layer and turning the one or more cover layers into a colored state to turn the data layer into an invisible state, or by preventing the confidential information from being recognized by the cover layers, and the confidential information may be visibly recognized in the visible wavelength range by turning the one or more cover layers into a decolored state to turn the data layer into a visible state; thus, confidential information can be visualized in the visible wavelength range.

According to the drawing device of the embodiment of the present disclosure, the confidential information may be hidden by performing writing on the data protector by the drawing device and changing the one or more cover layers into the colored state to change the data layer into the invisible state, or by preventing the confidential information from being recognized by the cover layers, and the confidential information may be visibly recognized in the visible wavelength range by performing erasing on the data protector by the drawing device and changing the one or more cover layers into the decolored state to change the data layer into the visible state; thus, confidential information can be visualized in the visible wavelength range.

This application claims the benefit of japanese priority patent application JP2019-052744, filed at the japanese patent office on 3/20/2019, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may be made in accordance with design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

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