阅读说明：本技术 装饰部件制造装置及装饰部件制造方法 (Decorative part manufacturing device and decorative part manufacturing method ) 是由 水野知章 于 2019-08-23 设计创作，主要内容包括：本发明提供一种能够不损害装饰层的质感地削减流体的使用量的装饰部件制造装置及装饰部件制造方法。在本发明的装饰部件制造装置及装饰部件制造方法中,将接受光而固化的流体从喷出部朝向基材表面喷出,为了在基材表面的各部位形成构成装饰层的固化凸部,从照射部对着落于各部位的流体照射光,根据用于在基材表面的各部位形成具有所设定的厚度的固化凸部的控制数据来控制喷出部。并且,校正部对控制数据实施校正处理,所述校正处理在根据控制数据控制喷出部时形成的固化凸部的厚度与固化凸部的空间频率的对应关系中,减少与设定值以下的空间频率对应的厚度。(The invention provides a decorative component manufacturing device and a decorative component manufacturing method, which can reduce the use amount of fluid without damaging the texture of a decorative layer. In the decorative part manufacturing apparatus and the decorative part manufacturing method of the present invention, the fluid cured by receiving light is ejected from the ejection portion toward the surface of the base material, and in order to form the cured convex portions constituting the decorative layer at each portion of the surface of the base material, the fluid falling at each portion is irradiated with light from the irradiation portion, and the ejection portion is controlled based on control data for forming the cured convex portions having a set thickness at each portion of the surface of the base material. The correction unit performs, on the control data, correction processing for reducing a thickness corresponding to a spatial frequency equal to or less than a set value in a correspondence relationship between the thickness of the cured convex portion formed when the ejection unit is controlled based on the control data and the spatial frequency of the cured convex portion.)

1. A decorative member manufacturing apparatus for manufacturing a decorative member having a decorative layer on a surface of a base material, the decorative member manufacturing apparatus comprising:

a discharge unit that discharges a fluid that is cured by receiving light toward a surface of the substrate;

an irradiation section that irradiates light onto the fluid that falls on each portion of the surface of the base material in order to form a cured convex portion that constitutes the decorative layer on each portion;

a control unit that controls the ejection unit based on control data for forming the solidification protrusion having the set thickness at each of the portions; and

and a correction unit that performs correction processing on the control data, the correction processing reducing a thickness corresponding to a spatial frequency equal to or less than a set value in a correspondence relationship between a thickness of the solidified convex portion and a spatial frequency of the solidified convex portion, the correspondence relationship being formed when the control unit controls the ejection unit based on the control data.

2. The decorative member manufacturing apparatus according to claim 1,

the correction processing is processing of weighting the thickness of the cured convex portion according to the corresponding spatial frequency,

in the correction processing, a weight of less than 1 is given to the thickness of the cured convex portion corresponding to a spatial frequency equal to or less than the set value, and a weight of 1 is given to the thickness of the cured convex portion corresponding to a spatial frequency greater than the set value.

3. The decorative member manufacturing apparatus according to claim 2,

the correction section performs the correction process using a weighting filter,

the weighting filter is a filter that is made in accordance with an iso-sensitivity curve that represents a change in a characteristic amount of a stimulus in which a person feels the same intensity by tactile sensation in association with a generation frequency of the stimulus,

the set value is a value set according to the frequency of generation of the stimulus having the smallest characteristic amount in the isosensitivity curve.

4. The decorative member manufacturing apparatus according to claim 3, wherein,

the stimulus with the smallest characteristic quantity in the isosensitivity curve is generated at a frequency of 250 Hz.

5. The decorative member manufacturing apparatus according to any one of claims 2 to 4, wherein,

in the correction process, the weight given to the thickness of the cured convex portion corresponding to the spatial frequency equal to or lower than the set value is increased as the spatial frequency is higher.

6. The decorative member manufacturing apparatus according to claim 3, wherein,

the weighting filter is a high-pass filter with a peak value set in a range of 1-6.5 cycles/mm.

7. The decorative member manufacturing apparatus according to claim 3, wherein,

the weighting filter is a high pass filter with the peak set at 1.8 cycles/mm.

8. The decorative member manufacturing apparatus according to any one of claims 1 to 7, wherein,

the correction processing is processing of reducing the thickness of the cured convex portion corresponding to a spatial frequency equal to or less than the set value in the correspondence relationship, and setting the thickness of the cured convex portion corresponding to a spatial frequency equal to or less than a threshold value smaller than the set value in the correspondence relationship to zero,

the threshold value is a critical value of a spatial frequency of the cured convex portion at which a person can recognize the cured convex portion by a tactile sensation.

9. The decorative member manufacturing apparatus according to any one of claims 1 to 8, wherein,

the control unit controls the ejection unit based on the corrected control data, and the cured convex portion, of which the thickness is reduced by the correction, is recessed at a central portion thereof by an amount corresponding to a reduction in thickness.

10. A method for manufacturing a decorative member having a decorative layer on a surface of a base material, the method comprising:

a discharge step of discharging the fluid solidified by receiving the light toward the surface of the substrate by a discharge section; and

an irradiation step of irradiating the fluid falling on each part with light via an irradiation portion so as to form a cured convex portion constituting the decorative layer on each part of the surface of the base material,

in the ejection step, the ejection section is controlled by a control section based on control data for forming the solidified convex sections having the set thicknesses at the respective portions,

and a correction unit that applies correction processing to the control data, the correction processing reducing a thickness corresponding to a spatial frequency equal to or less than a set value in a correspondence relationship between a thickness of the solidified convex portion and a spatial frequency of the solidified convex portion, the thickness being formed when the control unit controls the ejection unit based on the control data.

Technical Field

The present invention relates to a decorative member manufacturing apparatus and a decorative member manufacturing method, and more particularly to a decorative member manufacturing apparatus and a decorative member manufacturing method for manufacturing a decorative member having a decorative layer on a surface of a base material using a fluid that is cured by receiving light.

Background

As an apparatus for manufacturing a decorative member having a decorative layer with an uneven shape, there is known an ink jet printer or the like which ejects a fluid, which is cured by receiving light such as a transparent ink, toward a surface of a substrate and then irradiates the landed fluid with light. In such a device, the texture of the decorative layer can be adjusted by controlling the amount of fluid used, the landing position, the thickness after curing (i.e., the cured convex portion), and the like.

Further, in recent years, an apparatus has been developed which appropriately reproduces the unevenness when forming the decoration layer based on data for forming the decoration layer (hereinafter, also referred to as unevenness data). For example, the irregularity forming device described in patent document 1 acquires irregularity data, forms irregularities based on the acquired irregularity data, and changes operating conditions (specifically, the type of ink used, the light irradiation intensity, and the like) during irregularity formation based on the characteristic amount of the irregularities (specifically, the frequency component of the irregularity data, and the like) indicated by the irregularity data. According to the apparatus thus configured, sharpness and smoothness of the unevenness can be appropriately reproduced.

Another example of an apparatus for appropriately reproducing the unevenness is an unevenness forming apparatus described in patent document 2. When forming unevenness on a recording medium based on unevenness data, the apparatus corrects the unevenness data according to the frequency band and amplitude based on the frequency response characteristics at the time of forming the unevenness. According to the device having such a configuration, even if the frequency response characteristic changes in accordance with the amplitude amount of the input data, the operating condition of the device, or the like, the change can be flexibly coped with, and a concave-convex shape having good characteristics can be formed.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-13671

Patent document 2: japanese patent laid-open publication No. 2016-74146

Disclosure of Invention

Technical problem to be solved by the invention

However, in the production of decorative parts having a decorative layer having an uneven shape, it is required to reduce the amount of fluid used from the viewpoints of reduction in production cost, improvement in production speed, and the like. In particular, when a fluid such as a transparent ink is superimposed on the surface of a substrate to impart texture, the fluid needs to be applied in a superimposed manner more than usual in order to improve the authenticity of the texture, and therefore the production speed (specifically, the formation speed of the decorative layer) may be slow. Such a problem is remarkable in the case of employing the reciprocating scanning type inkjet printing method, and may become an obstacle to realizing market expansion of decorative parts.

It is needless to say that when the amount of fluid used is reduced, the reduction is required so as not to impair the texture of the decorative layer (specifically, the feeling of unevenness felt by a human).

On the other hand, the devices described in patent documents 1 and 2 are devices that change the operating conditions of the devices and correct the irregularity data for the purpose of forming irregularities satisfactorily, but are not devices that can reduce the amount of fluid used without impairing the texture of the decorative layer.

The present invention has been made in view of the above circumstances, and an object thereof is to solve the following object.

An object of the present invention is to solve the above-described problems of the conventional art and to provide a decorative part manufacturing apparatus and a decorative part manufacturing method capable of reducing the amount of fluid used without impairing the texture of the decorative layer.

Means for solving the technical problem

In order to achieve the above object, a decorative part manufacturing apparatus according to the present invention is a decorative part manufacturing apparatus for manufacturing a decorative part including a decorative layer on a surface of a base material, the decorative part manufacturing apparatus including: a discharge unit that discharges a fluid that is cured by receiving light toward a surface of a substrate; an irradiation section for irradiating light onto the fluid falling on each part in order to form a cured convex portion constituting the decorative layer on each part of the surface of the base material; a control unit for controlling the ejection unit based on control data for forming a solidification protrusion having a set thickness at each part; and a correction unit that performs correction processing on the control data, the correction processing reducing a thickness corresponding to a spatial frequency equal to or less than a set value in a correspondence relationship between a thickness of the cured convex portion and a spatial frequency of the cured convex portion, the thickness being formed when the control unit controls the ejection unit based on the control data.

According to the decorative part manufacturing apparatus of the present invention configured as described above, when manufacturing a decorative part having a decorative layer with an uneven shape using a fluid that is cured by receiving light, the amount of fluid used can be reduced without impairing the texture of the decorative layer.

In the decorative member manufacturing apparatus, it is more preferable that the correction process is a process of weighting the thickness of the cured convex portion according to the corresponding spatial frequency, and in the correction process, a weight of less than 1 is given to the thickness of the cured convex portion corresponding to the spatial frequency equal to or less than the set value, and a weight of 1 is given to the thickness of the cured convex portion corresponding to the spatial frequency greater than the set value.

According to the above configuration, in the correction process, a weight of less than 1 is given to the thickness of the cured convex portion corresponding to the spatial frequency equal to or less than the set value. This reduces the thickness of the cured convex part corresponding to the spatial frequency equal to or lower than the set value, and reduces the amount of fluid used by that amount.

In the decorative member manufacturing apparatus, it is more preferable that the correction unit performs the correction process using a weighting filter which is created from an iso-sensitivity curve indicating a change in the characteristic amount of the stimulus having the same intensity as the human senses with the sense of touch and the generation frequency of the stimulus, and the set value is a value set based on the generation frequency of the stimulus having the smallest characteristic amount in the iso-sensitivity curve.

According to the above configuration, the weighting filter is created from the equal sensitivity curve, and the set value is set. Thus, the weighting filter and the setting value can be appropriately determined according to the spatial frequency of the irregularities that are hard to be felt by human touch.

In addition, the frequency of generation of the stimulus with the smallest characteristic amount in the iso-sensitivity curve may be 250 Hz.

In the decorative member manufacturing apparatus, it is more preferable that the correction process be performed such that the weight given to the thickness of the cured convex portion corresponding to the spatial frequency equal to or lower than the set value is increased as the spatial frequency is higher.

According to the above configuration, the weight given to the thickness of the cured convex portion corresponding to the spatial frequency equal to or lower than the set value increases as the spatial frequency increases. Therefore, the thickness of the cured convex portion can be gradually changed at a spatial frequency equal to or lower than the set value, and the discomfort caused when the thickness is abruptly changed (discontinuously changed) can be suppressed.

Further, in the decorative part manufacturing apparatus, it is more preferable that the weighting filter is a high-pass filter having a peak value set in a range of 1 to 6.5 cycles/mm.

Here, it is further preferable that the weighting filter is a high-pass filter with a peak value set at 1.8 cycles/mm.

According to the above configuration, the weighting filter corresponds to a spatial frequency of the unevenness that is hard to be perceived by the touch of the human fingertip. By using such a weighting filter, the thickness of the solidified convex portion formed at a spatial frequency that is hard to be felt by the touch of a human fingertip can be appropriately reduced, and the amount of fluid used can be reduced accordingly.

In the decorative member manufacturing apparatus, it is more preferable that the correction process is a process of reducing the thickness of the cured convex portion corresponding to a spatial frequency equal to or less than a set value in the correspondence relationship, and setting the thickness of the cured convex portion corresponding to a spatial frequency equal to or less than a threshold value that is a threshold value at which a person can recognize the spatial frequency of the cured convex portion by feel to zero in the correspondence relationship.

According to the above configuration, the thickness of the solidified convex portion corresponding to the spatial frequency less than or equal to the threshold value of the set value can be set to zero, and the amount of fluid used can be further reduced.

In the decorative member manufacturing apparatus, it is more preferable that the central portion of the cured convex portion whose thickness is reduced by the correction is recessed by an amount corresponding to the amount of reduction in thickness, among the cured convex portions generated when the control unit controls the ejection unit based on the corrected control data.

According to the above configuration, the amount of fluid used can be reduced with a decrease in thickness. Further, for example, when the thickness is reduced to 0, the fluid ejection may not be performed at that portion, and therefore, the manufacturing speed of the decorative member can be increased accordingly (that is, the time required for the fluid ejection can be shortened).

In order to solve the above-described problems, a method for manufacturing a decorative member according to the present invention is a method for manufacturing a decorative member including a decorative layer on a surface of a base material, the method including: a discharge step of discharging the fluid solidified by receiving the light toward the surface of the substrate by the discharge section; and an irradiation step of irradiating light with respect to the fluid falling on each part by the irradiation section in order to form the cured convex portion constituting the decorative layer on each part of the surface of the base material, wherein in the ejection step, the ejection section is controlled by the control section based on control data for forming the cured convex portion having a set thickness on each part, and the control data is subjected to a correction process by the correction section, the correction process reducing the thickness corresponding to a spatial frequency equal to or less than a set value in a correspondence relationship between the thickness of the cured convex portion formed when the control section controls the ejection section based on the control data and the spatial frequency of the cured convex portion.

According to the above method, when a decorative member having a decorative layer with an uneven shape is manufactured using a fluid that is cured by receiving light, the amount of the fluid used can be reduced without impairing the texture of the decorative layer.

Effects of the invention

According to the present invention, a decorative part manufacturing apparatus and a decorative part manufacturing method capable of reducing the amount of fluid used without impairing the texture of a decorative layer are realized.

Drawings

Fig. 1 is a schematic cross-sectional view of the decorative layer.

Fig. 2 is a conceptual diagram illustrating a configuration of a decorative member manufacturing apparatus according to an embodiment of the present invention.

Fig. 3 is a schematic diagram showing a mechanical structure of the inkjet printer.

Fig. 4 is a view showing a nozzle surface of the recording head.

Fig. 5 is an explanatory diagram of control data.

Fig. 6 is a graph showing an isosensitivity curve.

Fig. 7 is a diagram showing a weighting function.

Fig. 8 is an explanatory diagram of the corrected control data.

Fig. 9 is a flow chart showing a manufacturing process of the decorative member.

Fig. 10 is a schematic cross-sectional view of a cured convex portion reduced in thickness by correction.

Detailed Description

Hereinafter, a decorative member manufacturing apparatus and a decorative member manufacturing method according to an embodiment (present embodiment) of the present invention will be described in detail with reference to preferred embodiments shown in the drawings.

The embodiments described below are merely examples for facilitating understanding of the present invention, and do not limit the present invention. That is, the present invention can be modified or improved from the embodiments described below without departing from the scope of the present invention. And, of course, the invention includes equivalents thereof.

In the present specification, the numerical range expressed by the term "to" refers to a range in which the numerical values before and after the term "to" are included as the lower limit value and the upper limit value.

[ decorative Member manufacturing apparatus ]

The decorative member manufacturing apparatus 10 of the present embodiment is an apparatus for manufacturing a decorative member using a color ink and a transparent ink. The decorative member is produced by forming a decorative layer having an uneven shape on the surface of a base material, and a predetermined texture (feel) is imparted by the decorative layer. The substrate is composed of paper such as sheet paper and roll paper, a resin film (e.g., plastic film) and sheet, a wooden, glass, or metal or resin plate or panel. As shown in fig. 1, the decoration layer a is formed by superimposing a transparent ink image D formed of transparent ink on a color ink image C printed on the surface of the substrate B with color ink. Fig. 1 is a schematic cross-sectional view of decorative layer a.

In the present embodiment, the decoration layer a is formed by superimposing the transparent ink image D on the color ink image C, but the invention is not limited to this, and the decoration layer a may be formed by forming the transparent ink image D first and recording (printing) the color ink image C thereon. Alternatively, instead of forming the color ink image C and the transparent ink image D separately, the decorative layer a may be formed using a color ultraviolet curable ink or the like.

The decorative layer a has an uneven shape as shown in fig. 1, that is, the thickness of each part of the decorative layer a is set to a size set for each part, and the thickness varies from part to part. Here, each part of the decorative layer a is composed of a cured convex portion E formed by curing the transparent ink that lands on each part of the surface of the base material. The cured convex portions E are formed of 1 or 2 or more layers of cured transparent ink. The thickness of the cured convex portions E corresponds to the thickness of each portion of the decorative layer a, and the thickness of the cured convex portions E increases as the number of layers of the cured transparent ink increases.

In the following description of the configuration of the decorative component manufacturing apparatus 10 according to the present embodiment, as shown in fig. 2, the decorative component manufacturing apparatus 10 according to the present embodiment includes an inkjet printer 20 and a host computer 30 as main components. Fig. 2 is a conceptual diagram illustrating the structure of the decorative member manufacturing apparatus 10 according to the present embodiment. The inkjet printer 20 and the host computer 30 will be described below.

< ink jet Printer >

The ink jet printer 20 is a device that ejects color ink and transparent ink to form the decorative layer a on the surface of the substrate, and as shown in fig. 2, includes a conveying unit 21, an ejection unit 22, an irradiation unit 23, and a control unit 24. The conveying unit 21 conveys the substrate B in a predetermined conveying direction, and may be constituted by a conveying roller or a conveying belt as shown in fig. 3. Further, a platen 21a of fig. 3 is disposed at a position midway along the conveyance path of the base material B. Fig. 3 is a diagram showing a mechanical structure of the inkjet printer 20.

The ejection section 22 ejects the color ink and the clear ink toward the surface of the substrate B while the substrate B is placed on the platen 21 a. The color ink is a color ink containing a pigment or a dye, and is a general ink used for color printing or the like. The transparent ink is an ultraviolet-curable fluid that is cured by receiving light (specifically, ultraviolet rays). The fluid discharged from the discharge section 22 may be any fluid that can be cured by light irradiation, and examples of the irradiation light include ultraviolet light, infrared light, and visible light. The main component of the fluid is a composition containing at least a polymerizable compound and a photoinitiator, and examples thereof include a cationic polymerization ink composition, a radical polymerization ink composition, and an aqueous ink composition.

In the present embodiment, as shown in fig. 2, the discharge unit 22 has two types of recording heads (inkjet heads) 22a and 22b, and forms the decoration layer a on the surface of the base material by a reciprocating scanning method. The first recording head 22a discharges color inks, and as shown in fig. 4, on the lower surface (nozzle surface) thereof, a plurality of nozzles n (nozzle groups) are provided in a row in the transport direction for each color of the color inks, specifically, for yellow (Y), black (K), cyan (C), and magenta (M). Fig. 4 shows nozzle groups formed on the lower surfaces of the recording heads 22a and 22 b.

The second recording head 22b discharges the clear ink, and as shown in fig. 4, a plurality of nozzle groups are provided in a row along the transport direction on the lower surface thereof at intervals in a direction (scanning direction) orthogonal to the transport direction. The clear ink recording head 22b is disposed downstream of the color ink recording head 22a in the transport direction.

The recording heads 22a and 22b are disposed at positions directly above the platen 21a, and reciprocate (scan) in the scanning direction. While the recording heads 22a and 22b are moving in the scanning direction, the piezoelectric elements (not shown) built in the recording heads 22a and 22b are driven, whereby droplets of the ink of the type corresponding to the nozzles n are discharged from the nozzles n. The ejected droplets of ink land on the surface of the substrate to form dots. The ink discharge method is not limited to the piezoelectric element (piezoelectric element) method, and various methods such as a thermal bubble jet method in which ink is heated by a heating element such as a heater to generate bubbles and ink droplets are scattered by the pressure of the bubbles can be applied instead of the piezoelectric method.

In the present embodiment, since the recording head 22b for clear ink is disposed downstream of the recording head 22a for color ink, dots of clear ink are formed on the portions of the substrate surface where the dots of color ink are formed (i.e., the landing portions of color ink). Further, since a plurality of nozzle groups are provided along the scanning direction on the lower surface of the recording head 22b for clear ink, clear ink can be ejected toward the same portion on the surface of the substrate a plurality of times (strictly speaking, the number of times corresponding to the number of nozzle groups, 4 times in the configuration shown in fig. 4) in one scan (movement) of the recording head 22 b. This makes it possible to overlap a plurality of dots of the transparent ink on each portion of the surface of the substrate.

In the present embodiment, the color ink recording head 22a and the clear ink recording head 22b are provided separately, but the present invention is not limited to this, and for example, both the color ink and the clear ink may be ejected from one recording head. The color ink recording head 22a may be provided for each color (specifically, for each of YMCK4 colors). In the present embodiment, the recording heads 22a and 22b are serial inkjet heads and print in the reciprocating scanning method, but the present invention is not limited to this, and printing may be performed in a single-pass method using a full-line inkjet head, for example.

The irradiation unit 23 irradiates light, more specifically, ultraviolet light, to the transparent ink landed on the surface of the substrate. The transparent ink that has been irradiated with the ultraviolet light from the irradiation section 23 is cured. As the irradiation unit 23, a metal halide lamp, a high-pressure mercury lamp, an ultraviolet LED (Light Emitting Diode), or the like can be used.

In the present embodiment, as shown in fig. 2 and 4, the irradiation portion 23 includes a pin portion 23a and a main curing portion 23 b. The pin portions 23a are irradiated with ultraviolet light at an irradiation intensity of a level to semi-cure the dots of the transparent ink. The semi-curing refers to a state in which the clear ink is cured to such an extent that the dot shape can be maintained (i.e., not spread by flow) without completely curing the clear ink. The main curing unit 23b irradiates ultraviolet rays with an irradiation intensity at a level of main curing (complete curing) of the semi-cured dots of the transparent ink.

In the present embodiment, a plurality of pinning portions 23a are disposed on the lower surface of the transparent ink recording head 22 b. Further, the pinning portions 23a are provided for the respective nozzle groups for ejecting the clear ink. As shown in fig. 4, each of the pinning portions 23a is disposed at a position adjacent to the corresponding nozzle row in the scanning direction. As a result, the clear ink (dots of clear ink) ejected from the nozzles n of each nozzle group and landed on the surface of the base material is semi-cured immediately after receiving the ultraviolet light irradiated from the pinning portions 23 a. In the present embodiment, as described above, new clear ink can be deposited in a manner to overlap the semi-cured clear ink dots, and the transparent ink dots can be semi-cured immediately after receiving the ultraviolet light from the pin portions 23 a.

Then, the main curing unit 23b irradiates the overlapped semi-cured transparent ink with ultraviolet rays. Specifically, as shown in fig. 4, the main curing section 23b is disposed on the side of the transparent ink recording head 22b and moves in the scanning direction together with the recording head 22 b. While the recording head 22b is moving, the main curing section 23b is irradiated with ultraviolet rays toward the portions of the surface of the base material through which all the pin sections 23a pass. Thereby, the transparent ink (dots of the transparent ink) superimposed in a semi-cured state on the surface of the substrate is subjected to the ultraviolet light irradiated from the main curing unit 23b and is main cured. Thereby, the cured convex portions E are formed on the respective portions of the surface of the base material. Here, the thickness of the cured convex portion E formed at each portion is a thickness corresponding to the number of dots of the transparent ink superimposed at each portion (in other words, the total value of the thicknesses of the dots of the superimposed transparent ink).

The positions and the number of the pins 23a and the main curing portions 23B are not particularly limited, and the pins 23a and the main curing portions 23B may be disposed at the side end of the platen 21a, and irradiated with ultraviolet light from the side of the base material B.

The control unit 24 is a controller incorporated in the inkjet printer 20, and controls the transport unit 21, the ejection unit 22, and the irradiation unit 23 via a drive circuit. Specifically, when the control unit 24 receives an instruction for manufacturing a decorative member transmitted from the host computer 30, the control unit 21 controls the base material B placed at a predetermined position of the ink jet printer 20 to be intermittently conveyed in the conveying direction.

The control unit 24 controls the discharge unit 22 (strictly, the color ink recording head 22a) based on the print data until the intermittent conveyance of the base material B by the conveyance unit 21 is stopped and restarted. The print data is data transmitted from the host computer 30 together with instructions for manufacturing the decorative member, and defines the discharge amount of the color ink (in other words, the size of the ink dot), the discharge timing, the landing position (in other words, the formation position of the ink dot), and the like. Under the control of the control section 24, the color ink recording heads 22a eject color inks of the respective colors toward the substrate surface, thereby forming dots of the color inks of the respective colors at portions of the substrate surface that face the nozzle surfaces of the recording heads 22 a. The control unit 24 alternately repeats the intermittent conveyance step of the base material B by the conveyance unit 21 and the ejection step of the color ink by the recording head 22a, thereby forming a color ink image C composed of dots of the color ink of each color on the surface of the base material.

The control unit 24 controls the discharge unit 22 (strictly, the recording head 22b for clear ink) based on the control data until the intermittent conveyance of the base material is stopped and restarted. The control data is data transmitted from the host computer 30 together with an instruction for manufacturing the decorative part, and defines the amount of ejection of the transparent ink, the ejection timing, the number of times the transparent ink is superimposed on each portion of the base material surface (in other words, the thickness of the cured convex portion E formed on each portion of the base material surface), and the like. That is, the control data can be said to be data for forming the cured convex portions E having a set thickness at each portion of the surface of the base material.

Under the control of the control unit 24, the recording head 22b for clear ink ejects clear ink toward each portion of the surface of the substrate, and overlaps dots of the clear ink a number of times corresponding to each portion. At this time, the controller 24 controls the irradiation unit 23 (specifically, each of the pin-bonding portions 23a and the main curing portion 23b) so as to irradiate ultraviolet rays with a predetermined irradiation intensity. As a result, the dots of the clear ink landed on the surface of the substrate are semi-cured immediately after landing, and are fully cured after the dots of the clear ink are overlapped a predetermined number of times. As a result, the cured convex portion E having a thickness defined by the control data is formed at a portion of the substrate surface facing the nozzle surface of the recording head 22 b. Then, the control section 24 repeats the intermittent conveyance process of the substrate B by the conveyance section 21, the ejection process of the transparent ink by the recording head 22B, and the irradiation process of the ultraviolet rays by the irradiation section 23, thereby forming the transparent ink image D composed of the cured convex portions E on the color ink image C formed on the surface of the substrate.

< host computer >

The host computer 30 is communicably connected to the ink jet printer 20, and executes programs such as an application program for manufacturing a decorative component and a printer driver. The printer driver converts data (image data) of an image generated by the decorative component manufacturing application program into the print data.

The printer driver generates the control data based on a tactile pattern specified by a user (manufacturer of the decorative component) when the image data and the decorative component manufacturing application are executed. The tactile sensation pattern is a pattern in which the user can specify the tactile sensation (texture) of the decorative layer a provided as a decorative member of the final product. More specifically, the user specifies the tactile sensation pattern from a plurality of candidates (for example, a pattern for "roughening" the surface and a pattern for "smoothing" the surface) set for the degree of unevenness of the decorative layer a.

The printer driver is recorded on a recording medium readable by the host computer 30 such as an optical disk, or can be downloaded to the host computer 30 via a communication network such as the internet.

As shown in fig. 2, the host computer 30 includes a print data generation unit 31, a control data generation unit 32, a correction unit 33, and a data transmission unit 34.

The print data generating unit 31 receives image data from the decorative component manufacturing application program and generates print data based on the image data. The image data is color image data representing an original image of the color ink image C formed on the surface of the substrate. The print data generation unit 31 performs resolution conversion processing, color conversion processing, halftone processing, and rasterization processing on the received image data.

The resolution conversion process is a process of converting image data into a resolution that can be reproduced by the inkjet printer 20, specifically, data indicating gradation values (specifically, values of 0 to 255) of each of red (R), green (G), and cyan (B). The color conversion process is a process of converting the color (i.e., RGB3 color) indicated by the resolution-converted image data into the color of ink that can be ejected by the inkjet printer 20 (i.e., YMCK4 color) with reference to a color conversion look-up table (not shown). The halftone process is a process of converting image data converted into gradation values of YMCK colors by the color conversion process into size data of dots of color ink formed in each pixel. The rasterizing process is a process of dividing the image data after the halftone process into pixel units and rearranging the divided image data in the order of transfer to the inkjet printer 20.

The control data generating part 32 receives the image data and the result of specifying the tactile pattern from the decorative part manufacturing application program, and generates control data based on these. Specifically, the thickness of each part of the decorative layer a, that is, the thickness of the cured convex portion E formed in each part is set based on the color information and density (tone value) of each pixel represented by the image data and the designated tactile pattern. Then, the set thickness of the cured convex portion E is converted into the thickness of each pixel, thereby generating control data shown in fig. 5. Fig. 5 is an explanatory diagram of control data. For convenience of illustration, the number of pixels shown in fig. 5 is smaller than the actual number of pixels.

When the control data is described with reference to fig. 5, the thickness, more precisely the number of times the dots of clear ink are superimposed, is defined for each pixel (in fig. 5, the minimum square). Here, the numerical value described in each pixel in fig. 5 corresponds to a set value of the thickness. In the control data, 1 pixel having a thickness of 1 or more or adjacent 2 or more pixel groups (hatched pixels in fig. 5) exist in a floating island shape, and each pixel in these pixel groups corresponds to a pixel constituting the cured convex portion E.

The control data is not limited to the above data, and other control data may be considered. For example, the data indicating the thickness of the cured convex portion E may be the data of the bitmap value in the same manner as the image data.

The correction unit 33 performs correction processing on the control data generated by the control data generation unit 32. The correction processing is processing for reducing the thickness of the component that is difficult to be recognized by a person, which is formed on the cured convex portion E of the decorative layer a. By performing the correction processing, the transparent ink consumption amount can be reduced and the manufacturing speed of the decorative member can be improved. The correction process will be described in detail below.

The correction process is a process of reducing the thickness of the cured convex portion E corresponding to the spatial frequency equal to or less than the set value in the correspondence relationship between the thickness of the cured convex portion E formed at each portion of the surface of the base material and the spatial frequency of the cured convex portion E when the control portion 24 controls the ejection portion 22 based on the control data.

More specifically, the correction process is a process of weighting the thickness of the cured convex portion E according to the corresponding spatial frequency. In the correction processing, a weight of less than 1 is given to the thickness of the cured convex portion E corresponding to a spatial frequency equal to or less than the set value, and a weight equal to 1 is given to the thickness of the cured convex portion E corresponding to a spatial frequency greater than the set value. Further, the higher the spatial frequency is, the more the weight given to the thickness of the cured convex portion E corresponding to the spatial frequency equal to or less than the set value is increased.

When the above weighting is performed, the correction unit 33 performs the correction process using the weighting filter.

Even when the control data is bitmap data, the correction process can be performed by performing a frequency decomposition and weighting filter process in the following steps. The control data after the correction processing is also data of a bitmap value.

To explain the specific procedure of the correction process, in the correction process, the correction unit 33 first performs frequency decomposition on the control data generated by the control data generation unit 32. In the frequency decomposition, for example, fourier transform or the like is applied to convert control data, which is data in real space, into data in frequency space.

In the control data subjected to frequency decomposition, the thickness of the cured convex portions E formed at each portion of the surface of the base material is correlated with the spatial frequency of the cured convex portions E having the thickness. When a specific example is described, for example, when the control data shown in fig. 5 is frequency-decomposed, the correspondence relationship as described above becomes clear, since the spatial frequency of the cured convex portion E having the thickness of 1 is f1, the spatial frequency of the cured convex portion E having the thickness of 2 is f2, the spatial frequency of the cured convex portion E having the thickness of 3 is f3, and the spatial frequency of the cured convex portion E having the thickness of 4 is f 4.

Next, the correction unit 33 applies a weighting filter to the control data after the frequency decomposition to weight the thickness of the cured convex portion E corresponding to each spatial frequency. The weighting filter is a filter produced from the iso-sensitivity curve shown in fig. 6. The isosensitivity curve (equal sensitivity) is a curve that represents a change in the characteristic amount of a stimulus in which a person feels the same intensity by tactile sensation in association with the generation frequency of the stimulus. Here, the iso-sensitivity curve shown in fig. 6 is a curve in which 1 group of vibration stimuli at the same level are felt on a human finger (specifically, the base of the thumb) although the vibration levels are physically different from each other in the space of the vibration parameters (verillo et al (1969)).

In addition, 2.9cm was used for each isosensitivity curve shown in FIG. 6²The vibration plane of (2) depicts characteristic quantities (amplitudes) that are perceived as equal intensity by changing the vibration frequency for the case where the perception level at the reference frequency of 250Hz becomes the threshold level and the case where the perception level becomes each level set at 5dB intervals within the range of 5dB to 55 dB. As is clear from fig. 6, the reference frequency of 250Hz corresponds to the frequency of generation of the stimulus with the minimum characteristic amount (amplitude) in the iso-sensitivity curve.

In the iso-sensitivity curve shown in fig. 6, a weighting filter is created from a curve (hereinafter, reference curve) in which the perception level at the reference frequency of 250Hz becomes 40 dB. This is because the vibration level (amplitude) at the reference frequency of 250Hz in the reference curve is about 10 μm, and the amplitude corresponds to the thickness of a normal convex portion formed by the inkjet printer 20 using the transparent ink.

Further, using the reference curve, the weighting function shown in fig. 7 was defined according to the average velocity when the surface of the object was drawn with a human fingertip being 14 cm/s. The weighting function is a function for determining a weight corresponding to a spatial frequency from a reference curve, and the filter representing the weighting function as a band filter is a weighting filter.

The weighting function shown in fig. 7 is merely an example, and other weighting functions may be considered. For example, in the weighting function shown in fig. 7, the weight equal to or less than the spatial frequency corresponding to the sensitivity threshold described later is 0, but the weight may be a value other than 0 (specifically, a value slightly larger than 0) even in a range equal to or less than the spatial frequency corresponding to the sensitivity threshold.

In the present embodiment, the weighting filter is a high-pass filter having a peak value set in a range of 1 to 6.5 cycles/mm, and more preferably a peak value set at 1.8 cycles/mm (250 Hz/14 cm/s). Here, the peak value of the high-pass filter corresponds to the set value. When the peak value of the high-pass filter is 1.8 c-cycle/mm, the set value is set according to the frequency of generation of the stimulus having the smallest characteristic amount in the iso-sensitivity curve shown in fig. 6 (i.e., 250 Hz).

In the present embodiment, the frequency of generation of the stimulus having the smallest characteristic amount in the iso-sensitivity curve is 250Hz, but the frequency at which the minimum value of the characteristic amount in the iso-sensitivity curve can be set is in the range of 200Hz to 1000Hz, and a frequency in this range can be set, and a frequency in the range of 250Hz to 300Hz is more preferable, and 250Hz is particularly preferable.

The correction unit 33 applies the above-described weighting filter to the control data subjected to the frequency decomposition (i.e., the control data expressed in the frequency space). Thus, the thickness of the cured convex portion E corresponding to the spatial frequency equal to or lower than the set value (peak value of the filter) is given a weight of less than 1, and the thickness of the cured convex portion E corresponding to the spatial frequency greater than the set value is given a weight equal to 1. As is clear from fig. 7, the thickness of the cured convex portion E corresponding to the spatial frequency equal to or lower than the set value is weighted more heavily as the spatial frequency is higher.

The weighting of the thickness is described below by taking specific examples. When the control data shown in fig. 5 is frequency-resolved, as described above, the spatial frequencies of the cured projections E having the thicknesses of 1, 2, 3, and 4 are f1, f2, f3, and f4, respectively, and the following magnitude relationship is established between these spatial frequencies and the set values (peak values of the weighting filter).

Set values < f1, f2, f3

f4 < set value

In the above case, since the spatial frequency of the respective cured convex portions E having the thicknesses of 1, 2, and 3 exceeds a set value, the weight of 1 is given to these cured convex portions E. On the other hand, the cured convex portion E having a thickness of 4 has a spatial frequency of a set value or less, and therefore is weighted less than 1. In this case, the weight given to the cured convex portion E having a thickness of 4 is given a larger weight as the spatial frequency is higher. Conversely, if the spatial frequency equal to or lower than the set value becomes smaller than or equal to the threshold value, a weight of 0 (zero) is given. Here, the threshold is a value smaller than the set value, and is a critical value at which a person can recognize the spatial frequency of the cured convex portion E by the tactile sensation.

In the present embodiment, it is considered that 25Hz or less corresponds to a sensitivity threshold in the iso-sensitivity curve, and if it is considered that the average velocity when the surface of the object is drawn with the human fingertip is 14cm/s, the threshold value is 0.18cycle/mm from these values. However, the threshold value is not limited to the above value, and other values may be used. For example, it is known that the speed of movement of the fingertip varies within a range of 3cm/s to 25cm/s, and the threshold value may be determined based on this range.

In the above-described case as a specific example, the spatial frequency of the cured convex portion E having a thickness of 4 is equal to or less than the threshold value, and the thickness of the cured convex portion E is corrected to 0 in the correction processing as shown in fig. 8. Fig. 8 is an explanatory diagram of the corrected control data.

The thickness of the cured convex portion E having a spatial frequency equal to or less than the threshold value may be 0 as in the above case, or may be a value other than 0 (for example, a value slightly larger than 0).

After the weighting processing is performed, the correction unit 33 applies inverse fourier transform to the weighted control data, and returns the frequency space control data to the real space data. As described above, in the correction processing of the present embodiment, the control data is converted into data in the frequency space, the weighting filter is applied to the converted control data, and the control data is returned to data in the real space after the weighting processing. However, the present invention is not limited to this, and the control data may be expressed as a function in real space, and convolution integration may be performed on the function and a function (weighting function) corresponding to a weighting filter.

After the correction processing is performed, when the decorative layer a is formed on the surface of the base material based on the corrected control data, the thickness of the cured convex portion E corresponding to the spatial frequency equal to or less than the set value decreases, and the thickness of the cured convex portion E corresponding to the spatial frequency equal to or less than the threshold value becomes zero. As will be understood, in the case of the above specific example, as is apparent from fig. 5 and 8, the thickness of each of the cured convex portions E having the thicknesses set to 1, 2, and 3 in the control data before correction is also set to 1, 2, and 3 after correction. On the other hand, the thickness of the cured convex portion E whose thickness is set to 4 in the control data before the correction is reduced by the correction, and strictly speaking, becomes 0. Therefore, when the ink jet printer 20 forms the decorative layer a on the surface of the base material based on the corrected control data, the thickness of the cured convex portion E, in which the initial thickness is set to 4, in the decorative layer a becomes 0. This can reduce the consumption of the clear ink.

Even when the control data is bitmap value data, the corrected control data (bitmap value) may be input as an ink ejection control signal, and the clear ink may be ejected to each portion of the surface of the substrate based on the control signal. This reduces the thickness of the cured convex portion E corresponding to the spatial frequency equal to or less than the set value, and can reduce the consumption amount of the clear ink.

As described above, in the present embodiment, the control data is corrected so that the thickness of the cured convex portions E formed in the cured convex portions E of the decorative layer a is reduced in accordance with a spatial frequency that is difficult to recognize with human fingertips (specifically, a spatial frequency equal to or lower than a set value). More specifically, in the reference curve in the iso-sensitivity curve shown in fig. 6, the characteristic amount (amplitude) of the stimulus becomes minimum at the reference frequency of 250Hz, and in the frequency band smaller than the reference frequency of 250Hz, the characteristic amount of the stimulus increases as the frequency decreases. That is, in a frequency band of 250Hz or less of the reference frequency, the sensitivity of the human fingertip is blunted.

As described above, in the present embodiment, the thickness of the cured convex portion E corresponding to the spatial frequency of not more than the set value (specifically, 1.8 cycles/mm) corresponding to the reference frequency of 250Hz is corrected so as to be smaller than the value before the correction. Such a configuration is different from the configuration of the device described in patent document 1 or patent document 2 in that the operating conditions of the device and the configuration of the correction control data (concave-convex data) are changed for the purpose of forming concave-convex portions satisfactorily. That is, in the present embodiment, the control data is corrected for a purpose different from the purpose described in patent document 1 or patent document 2, specifically, the control data is corrected for a purpose of reducing the amount of transparent ink used (specifically, the number of times of ejection) without impairing the texture (specifically, the feeling of unevenness perceived by a person) of the decorative layer a.

Further, by reducing the amount of transparent ink used, the manufacturing cost of the decorative member can be suppressed, and the manufacturing speed can be increased. This effect is particularly effective in the ink jet printer 20 that employs the reciprocating scanning method in which the original drawing speed is relatively slow.

[ manufacturing method of decorative Member ]

Next, a method of manufacturing a decorative member using the decorative member manufacturing apparatus 10 will be described with reference to fig. 9. Fig. 9 is a flow chart showing a manufacturing process of the decorative member.

In the decorative component manufacturing flow, first, print data and control data are created in the host computer 30 in cooperation with the application program for manufacturing the decorative component and the printer driver (S001). Then, the correction unit 33 of the host computer 30 performs a correction process on the control data (S002). By this correction processing, the correspondence relationship between the thickness of the cured convex portion E and the spatial frequency of the cured convex portion E formed when the ejection portion 22 is controlled based on the control data is determined, and the thickness corresponding to the spatial frequency equal to or less than the set value is reduced in the correspondence relationship. Specifically, the thickness corresponding to the spatial frequency equal to or less than the set value is weighted by a weighting filter to be less than 1, and is corrected so as to be the weighted thickness. The thickness corresponding to the spatial frequency equal to or lower than the threshold is corrected so as to be 0 (zero).

Then, the print data and the corrected control data are transmitted from the host computer 30 to the inkjet printer 20 together with an instruction for manufacturing the decorative member (S003). When the control unit 24 of the ink jet printer 20 receives the print data and the corrected control data from the host computer 30, the printer units are controlled based on these data (S004). That is, the control unit 24 of the ink jet printer 20 intermittently performs the step of conveying the base material B by the conveying unit 21, and performs the step of ejecting the color ink by the ejecting unit 22 while the conveying step is interrupted. In the color ink ejection step, the control section 24 controls the recording head 22a based on print data. Thereby, a color ink image C corresponding to the print data is formed on the surface of the base material.

The control unit 24 performs the clear ink discharging process by the discharging unit 22 and the irradiation process by the irradiation unit 23 while the conveyance process is interrupted. In the clear ink discharging step, the control section 24 controls the recording head 22b based on the corrected control data. In the irradiation step, the control unit 24 controls the pin portions 23a and the main curing portion 23b based on the corrected control data. Thus, the transparent ink image D is superimposed on the color ink image C formed on the surface of the base material to form the decorative layer a. In the decorative layer a formed based on the corrected control data, the thickness of the cured convex portion E formed at each portion of the decorative layer a is smaller than the thickness before correction, corresponding to the spatial frequency equal to or less than the set value.

As shown in fig. 10, the cured convex portion E whose thickness is reduced by the correction has a shape in which the central portion of the cured convex portion E is recessed in a recessed shape by an amount corresponding to the reduction in thickness. Fig. 10 is a schematic cross-sectional view of the cured convex portion E reduced in thickness by correction.

Then, a decorative layer a is formed on the surface of the base material at the time when the respective ejecting steps and the irradiating steps of the color ink and the clear ink are completed. Then, the conveying process is repeated until the base material B (i.e., the decorative member) on which the decorative layer a is formed reaches the discharge port of the ink jet printer 20, and the decorative member manufacturing flow is ended at the time of discharging the decorative member.

According to the decorative part manufacturing flow described above, the amount of transparent ink used (the number of times of ejection) can be reduced without impairing the texture of the decorative layer a by controlling the ejection of transparent ink in consideration of the sensitivity (feel) of the human fingertip. This makes it possible to manufacture the decorative member at a higher manufacturing speed while suppressing the manufacturing cost.

Description of the symbols

10-decorative part manufacturing apparatus, 20-inkjet printer, 21-conveying section, 21 a-platen, 22-ejecting section, 22a, 22B-recording head, 23-irradiating section, 23 a-pinning section, 23B-full curing section, 24-control section, 30-host computer, 31-print data generating section, 32-control data generating section, 33-correcting section, 34-data transmitting section, a-decorative layer, B-substrate, C-color ink image, D-transparent ink image, E-curing projection, n-nozzle.