阅读说明：本技术 测量用光学系统、色彩亮度计以及色彩计 (Optical system for measurement, color luminance meter, and color meter ) 是由 长泽仁 于 2018-04-26 设计创作，主要内容包括：本发明的测量用光学系统、色彩亮度计以及色彩计具备：光阑；光学波导,传导入射光；第一光学系统,被配置于光阑的物侧,并使来自测量对象的光像成像于光阑的孔径面；以及第二光学系统,被配置于光阑与光学波导之间,使从光阑的孔径面射出的各光束的各主光线以与光轴平行的方式入射至光学波导。(The optical system for measurement, the colorimeter and the colorimeter of the invention are provided with an aperture stop, an optical waveguide for transmitting incident light, an th optical system arranged on the object side of the aperture stop and forming an image of light from a measurement object on an aperture surface of the aperture stop, and a second optical system arranged between the aperture stop and the optical waveguide and causing each principal ray of each light flux emitted from the aperture surface of the aperture stop to enter the optical waveguide in parallel with the optical axis.)

1, measurement optical system, comprising:

a diaphragm;

an optical waveguide that guides incident light;

an th optical system disposed on the object side of the diaphragm and imaging the light from the measurement object on the aperture surface of the diaphragm, and

and a second optical system disposed between the aperture stop and the optical waveguide, and configured to cause each principal ray of each light flux emitted from the aperture surface of the aperture stop to enter the optical waveguide in parallel with the optical axis.

2. The measuring optical system according to claim 1,

the th optical system is composed of two lens groups, i.e., a th lens group and a second lens group, and the th lens group and the second lens group have positive refractive power and form an image of an optical image from a measurement object on an aperture surface of the stop so as to be telecentric on the object side.

3. The measuring optical system according to claim 1,

the th optical system is composed of lens groups that have positive refractive power and form an image of an optical image from a measurement object on an aperture surface of the stop so as to be telecentric on the object side.

4. The measurement optical system according to any of claim 1 to claim 3,

an image-side numerical aperture of the second optical system is greater than or equal to a numerical aperture of the optical waveguide.

5, kinds of color brightness meter, wherein,

the optical system for measurement according to any of claim 1 through claim 4 is used.

6, kinds of colorimeter, wherein,

the optical system for measurement according to any of claim 1 through claim 4 is used.

Technical Field

The present invention relates to a measurement optical system for transmitting light from a measurement object to a light receiving unit, a luminance colorimeter using the measurement optical system, and a colorimeter using the measurement optical system.

Background

Conventionally, a colorimeter that measures the color (light source color) and luminance of a light-emitting body as a measurement target object, and a colorimeter that measures the color (object color) of an object as a measurement target object have been variously used. Such a colorimeter or colorimeter uses a measuring optical system for guiding light from a measurement object to a light receiving portion, as disclosed in patent document 1, for example.

The optical device for measurement disclosed in patent document 1 includes an optical branching member having a plurality of emission surfaces that branch and emit light from a measurement target incident on an incident surface. More specifically, the optical device for measurement disclosed in patent document 1 includes an optical system KK2 (fig. 9, paragraph [0042], and the like) including an objective lens 103, an aperture stop 104, a field stop 105, a relay lens 106, and an optical fiber bundle 22. The objective lens 103 condenses and images the light beam from the measurement object Q at the position of the field stop 105. The relay lens 106 conducts the image imaged at the position of the field stop 105 to the entrance face a of the fiber bundle 22. The aperture stop 104 is disposed behind the objective lens 103, and only the light flux passing through the aperture stop 104 is directed toward the relay lens 106. The bundle fiber 22 corresponds to the optical branching member, and the bundle fiber 22 is configured by bundling a plurality of bare optical fibers, is divided into 3 pieces at the middle portion in the axial direction, and splits the light flux incident on the incident surface a to be emitted on 3 emission surfaces B1, B2, and B3. The relay lens 106 is disposed at a position optically conjugate to the aperture stop 104 and the incident surface a. In addition, the reference numerals in this paragraph are numerals assigned to the respective structures in the patent document 1.

Further, , in recent years, not only liquid crystal displays but also organic EL (electro luminescence) displays have been attracting attention as display devices, and these organic EL displays are capable of emitting light even in a low luminance range because of self-luminescence as compared with liquid crystal displays using a backlight.

In the optical device for measurement disclosed in patent document 1, a light beam having an incident angle equal to or larger than an angle adapted to the numerical aperture of the optical fiber bundle (bare optical fiber) cannot enter the optical fiber bundle (bare optical fiber), and a light amount loss occurs.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a measurement optical system capable of transmitting a larger amount of light from an object to be measured to a light receiving portion, a color luminance meter using the measurement optical system, and a colorimeter using the measurement optical system.

To achieve the above object, the -sided measurement optical system, the colorimeter, and the colorimeter according to the present invention include an aperture stop, an optical waveguide for transmitting incident light, a -th optical system disposed on an object side of the aperture stop and configured to form an image of light from a measurement target on an aperture plane (aperture plane) of the aperture stop, and a second optical system disposed between the aperture stop and the optical waveguide and configured to allow each principal ray of each light flux emitted from the aperture plane of the aperture stop to enter the optical waveguide in parallel with an optical axis.

The advantages and features provided by or more embodiments of the invention will be more fully understood from the detailed description given below and the accompanying drawings, which are given by way of example only and are not intended as a definition of the limits of the invention.

Drawings

Fig. 1 is a block diagram showing the structure of a color luminance meter according to embodiment .

Fig. 2 is a diagram showing a configuration of a measurement optical system used for the color luminance meter.

Fig. 3 is a ray diagram showing each light flux from the exit surface of the second optical system to the entrance surface of the optical waveguide in the measurement optical system.

Fig. 4 is a diagram showing the configuration of a measurement optical system in the second embodiment.

Fig. 5 is a diagram showing the configuration of a measurement optical system in the third embodiment.

Fig. 6 is a block diagram showing the structure of the colorimeter in the fourth to sixth embodiments.

Fig. 7 is a diagram showing the configuration of a measurement optical system in a comparative example.

Detailed Description

In the present specification, the reference numerals with the subscripts omitted are used for the sake of general reference, and the reference numerals with the subscripts added are used for the sake of designating individual configurations.

(embodiment )

Fig. 1 is a block diagram showing the configuration of the color luminance meter in embodiment , and fig. 1 is also a block diagram showing the configuration of the color luminance meters Db and Dc in the second and third embodiments described later.

Fig. 2 is a diagram showing a configuration of a measurement optical system using the color luminance meter, fig. 2A shows a ray diagram of each light flux from an exit surface of a second optical system to an entrance surface of an optical waveguide (optical fiber bundle) in an th embodiment, fig. 2B shows an example in which an optical fiber bundle is used as the optical waveguide, fig. 3 shows a ray diagram of each light flux from an exit surface of the second optical system to an entrance surface of the optical waveguide in the measurement optical system, fig. 7 is a diagram showing a configuration of the measurement optical system in a comparative example, fig. 7A shows the measurement optical system in the comparative example, and fig. 7B shows a ray diagram of each light flux from an exit surface of the second optical system to an entrance surface of the optical waveguide (optical fiber bundle) in the comparative example.

For example, as shown in fig. 1, the color luminance meter Da according to the includes a measurement optical system SSa, a light receiving unit 1, a control processing unit 2a, an input unit 3, an output unit 4, and an interface unit (IF unit) 5.

The measurement optical system SSa is an optical component that receives light from the object Ob to be measured as a measurement target and transmits the received light to the light receiving unit 1. The measurement optical system SSa will be described in more detail later. The object Ob to be measured is a light emitter that emits light because it is a color luminance meter Da in the present embodiment.

The light receiving unit 1 is a light receiving element that receives light from the object Ob to be measured transmitted by the optical system SSa for measurement, photoelectrically converts the received light, and outputs an electrical signal according to the light intensity. For example, the light receiving unit 1 includes a spectroscopic unit that disperses the received light from the measurement object Ob, and a photoelectric conversion element that photoelectrically converts the light dispersed by the spectroscopic unit. More specifically, in the present embodiment, since the color and the luminance of the object Ob are measured based on the 3 stimulus values of XYZ, the light receiving unit 1 includes 3X filters 11-1, Y filters 11-2, and Z filters 11-3 corresponding to the isochromatic function X, Y, Z defined by CIE (international commission on illumination), and an X filter light receiving element 12-1, a Y filter light receiving element 12-2, and a Z filter light receiving element 12-3 that receive and photoelectrically convert the light beams respectively filtered by the X filter 11-1, the Y filter 11-2, and the Z filter 11-3. In the light receiving unit 1, the light from the object Ob is filtered by the X-ray filter 11-1, the filtered light is received by the X-filter light receiving element 12-1 and photoelectrically converted, the X-filter light receiving element 12-1 outputs an electric signal (X signal) according to the intensity of the light, the light from the object Ob is filtered by the Y filter 11-2, the filtered light is received by the Y filter light receiving element 12-2 and photoelectrically converted, the Y filter light receiving element 12-1 outputs an electric signal (Y signal) according to the light intensity thereof, and the light from the object Ob to be measured is filtered by the Z filter 11-3, the filtered light is received by the Z-filter light receiving element 12-3 and photoelectrically converted, and the Y-filter light receiving element 12-1 outputs an electric signal (Z signal) according to the light intensity. The light receiving unit 1 is connected to the control processing unit 2a, and outputs the X signal, the Y signal, and the Z signal to the control processing unit 2 a.

The input unit 3 is connected to the control processing unit 2a, and is a device for inputting various commands such as a command for instructing measurement of the object Ob to be measured and various data necessary for measurement such as an identifier (sample number, ID, name, etc.) of the object Ob to be measured to the color luminance meter Da, and the input unit 3 is, for example, a plurality of input switches to which predetermined functions are assigned. The output unit 4 is connected to the control processing unit 2a and outputs commands and data input from the input unit 3 and the color and luminance of the object Ob measured by the colorimeter Da under the control of the control processing unit 2a, and the output unit 4 is a display device such as a CRT display, an LCD (liquid crystal display) or an organic EL display, or a printing device such as a printer.

In the case of configuring the touch panel, the input unit 3 may be a position input device for detecting and inputting an operation position such as a resistive film type or a capacitive type, and the output unit 4 may be a display device, in which the position input device is provided above a display surface of the display device, or a plurality of candidates of input contents that can be input are displayed on the display device, and when a user touches a display position where input contents desired to be input are displayed, the position is detected by the position input device, and the display contents displayed at the detected position are input as operation input contents of the user, and the color brightness meter Da is provided.

The IF unit 5 is a circuit connected to the control processing unit 2a and configured to input and output data to and from an external device in accordance with control of the control processing unit 2a, and the IF unit 5 is, for example, an interface circuit of RS-232C of a Serial communication system, an interface circuit using a Bluetooth (registered trademark) standard, an interface circuit performing Infrared communication such as an IrDA (Infrared data association) standard, and an interface circuit using a USB (Universal Serial Bus) standard. The IF unit 5 is a circuit for performing communication with an external device, and may be, for example, a data communication card, a communication interface circuit based on IEEE802.11 standard, or the like.

The control processing unit 2a controls each unit of the luminance color meter Da according to the functions of each unit 1, 3 to 5, and controls the entire luminance color meter Da. The control processing unit 2a measures the light from the object Ob by the measurement optical system SSa and the light receiving unit 1 in accordance with the instruction received by the input unit 3, obtains the color and brightness of the object Ob based on the electric signal output from the light receiving unit 1, and outputs the obtained color and brightness of the object Ob to the output unit 4. The control processing unit 2a outputs the obtained color and brightness of the object Ob from the IF unit 5 as necessary. In the present embodiment, the control processing unit 2a obtains the color and brightness of the object Ob to be measured from the X signal, the Y signal, and the Z signal output from the light receiving unit 1 by a known method. The control processing unit 2a is configured to include, for example, a microprocessor.

For example, as shown in fig. 2, the measurement optical system SSa includes a th optical system OSa-1, a diaphragm DI, a second optical system OSa-2, and an optical waveguide OP.

The diaphragm DI is an optical element for limiting the measurement diameter, and is a plate-shaped member having a light-shielding property and a circular through-hole corresponding to the measurement diameter, for example. The through hole diameter forms a hole diameter surface.

The optical waveguide OP is an optical element that transmits incident light, and in the present embodiment, the optical waveguide OP is an optical splitter that splits 3 incident light beams in order to transmit the light beams from the object Ob to the 3X filters 11-1, the Y filters 11-2, and the Z filters 11-3 in the light receiving unit 1, and more specifically, in the present embodiment, as shown in fig. 2B, the optical waveguide OP is an optical fiber beam that splits 3 bundled bare optical fibers into 3 bundles and emits the incident light beams from 1 incident surface to 3 exit surfaces, namely, th to third exit surfaces.

More specifically, in the present embodiment, as shown in fig. 2A, the optical system OSa-1 is configured by two lens groups of a and second lens groups Gra-1 and Gra-2, and the and the second lens groups Gra-1 and Gra-2 have positive refractive power (optical power, reciprocal of focal length) and image the optical image of the object to be measured Ob from the object to be measured on the aperture surface of the diaphragm DI as an intermediate image so as to be telecentric on the object side, and therefore, as shown in fig. 2A, the chief rays of the respective light beams emitted from the object to be measured Ob are incident on the lens group-1 so as to be parallel to the optical axis, and the parallelism of the chief rays to the optical axis refers not only to the case where the chief rays are perfectly parallel to the chief rays but also to the case where the chief rays deviate from the optical axis range of the second lens group Gra-1, graf, and graf 2, which are considered to be included in the range of errors between the second lens group of the graf-462 and the graf-2, and the range of ± 2, including the graf-2.

The second optical system OSa-2 is an optical element disposed between the diaphragm DI and the optical waveguide OP, and is used to make each principal ray of each light flux emitted from the aperture surface of the diaphragm DI enter the optical waveguide OP in parallel with the optical axis. That is, the second optical system OSa-2 is a relay lens telecentric on the image side, and is composed of, for example, 1 lens group Grb.

In the measurement optical system SSa as described above, as is apparent from the above description, the optical system OSa-1, the stop DI, the second optical system OSa-2, and the optical waveguide OP are arranged in this order, the stop DI is arranged at the imaging position of the optical system OSa-1, the light from the measured object Ob to be measured is made incident on the th lens group Gra-1 of the th optical system OSa-1, the th optical system OSa-1 makes the light image from the measured object Ob to be imaged on the aperture surface of the stop DI as an intermediate image by its positive refractive power so that the principal rays of the respective light beams are parallel to the optical axis, and the stop DI restricts the light from the measured object Ob by the measurement diameter and makes the light incident on the second optical system OSa-2, whereby the measurement optical system SSa can realize uniform and sharp-edged measurement sensitivity, and can transmit a large amount of light even with a relatively small measurement diameter, and the measurement optical system SSa does not have a non-telecentric relationship as it is difficult to be affected by the measurement optical system.

Further, since the second optical system OSa-2 causes the light from the object Ob to be measured, which is limited by the stop DI, to enter the optical waveguide OP. such that the principal rays of the respective light fluxes are parallel to the optical axis, the measurement optical system SSa can reduce the loss of light amount due to the large incident angle of the off-axis light fluxes, and the light collection efficiency is high, as described in more detail in the comparative example, as shown in fig. 7, the measurement optical system SSr of this comparative example has the same configuration as the above-described measurement optical system SSa shown in fig. 2 except that a lens group Grr which is not telecentric on the image side is used instead of the point of the lens group Grb of the second optical system OSa-2.

5634. in order to make more light incident into the optical waveguide OP, i.e. the optical fiber bundle OP in this embodiment, the numerical aperture NA1 on the image side of the optical system SSa is made to coincide with the numerical aperture NA2 of the optical waveguide (fiber bundle) OP, even if the numerical aperture NA1 and the numerical aperture NA2 are made to coincide with each other, in the case of the optical system SSr for measurement in the comparative example, as shown in fig. 7B, the axial light bundle consisting of light rays a _ +1, a _0, a _ -1 can all propagate in the optical waveguide (fiber bundle) OP, but since the optical beam r on the image side is not a beam r, the axial light bundle consisting of light rays a _ +1, a _0, a _ -1 is made to propagate in the optical waveguide OP, as shown in fig. 7B, the optical beam B _ +1, a _0, B _ -1 is made to coincide with the central axis of the optical waveguide p +1, B + 5, the optical fiber bundle B +1, B +.

The light from the object Ob to be measured that has entered the optical waveguide OP, that is, the optical fiber bundle OP in the present embodiment propagates through the optical fiber bundle OP, is divided into 3 parts, and is emitted from the th to the third emission surface.

In the present embodiment, as shown in fig. 2B, the optical fiber bundle OP and the light receiving unit 1 are arranged such that the incident surface of the X filter 11-1 of the light receiving unit 1 faces the th exit surface of the optical fiber bundle OP, the incident surface of the Y filter 11-2 of the light receiving unit 1 faces the second exit surface of the optical fiber bundle OP, and the incident surface of the Z filter 11-3 of the light receiving unit 1 faces the third exit surface of the optical fiber bundle OP.

Light from the object Ob to be measured emitted from the optical waveguide OP is incident on the light receiving unit 1. in the present embodiment, light from the object Ob to be measured emitted from the -th emission surface of the optical fiber bundle OP is incident on the X filter 11-1 of the light receiving unit 1, filtered by the X filter 11-1, and received by the X filter light receiving element 12-1. light from the object Ob to be measured emitted from the second emission surface of the optical fiber bundle OP is incident on the Y filter 11-2 of the light receiving unit 1, filtered by the Y filter 11-2, and received by the Y filter light receiving element 12-2. furthermore, light from the object Ob to be measured emitted from the third emission surface of the optical fiber bundle OP is incident on the Z filter 11-3 of the light receiving unit 1, filtered by the Z filter 11-1, and received by the Z filter light receiving element 12-3.

As described above, the X-filter light-receiving element 12-1 outputs the X signal corresponding to the light intensity of the light filtered by the X-filter 11-1 to the control processing unit 2a, the Y-filter light-receiving element 12-2 outputs the Y signal corresponding to the light intensity of the light filtered by the Y-filter 11-2 to the control processing unit 2a, and the Z-filter light-receiving element 12-3 outputs the Z signal corresponding to the light intensity of the light filtered by the Z-filter 11-3 to the control processing unit 2 a. The control processing unit 2a obtains the color and brightness of the object Ob from the X signal, the Y signal, and the Z signal output from the light receiving unit 1, and outputs the obtained color and brightness of the object Ob to the output unit 4.

As described above, in the measurement optical system SSa used in the color luminance meter Da in the present embodiment, the optical system OSa-1 forms an optical image of the object Ob to be measured from the measurement target on the aperture surface of the diaphragm DI to form an intermediate image, and the second optical system OSa-2 causes the chief rays of the respective light beams emitted from the aperture surface of the diaphragm DI to enter the optical waveguide (optical fiber bundle in the present embodiment) OP. so as to be parallel to the optical axis, so that the measurement optical system SSa can reduce the loss of light amount due to the off-axis light beams having a large incident angle, and thus the light collection efficiency is high.

In the measurement optical system SSa, the second optical system OSa-2 does not have an imaging relationship as in the case of double-sided telecentric and is hardly affected by unevenness of the measurement surface, and the optical system OSa-1 is composed of two lens groups of and second lens groups Gra-1 and Gra-2, so that the measurement optical system SSa can condense a larger amount of light and easily correct chromatic aberration as needed.

The use of the measurement optical system SSa as described above enables the color luminance meter Da of embodiment to have an improved SN ratio and to measure colors with higher accuracy, which is advantageous particularly in the measurement of a low luminance range.

(second embodiment)

Other embodiments will be described below. Fig. 4 is a diagram showing the configuration of a measurement optical system in the second embodiment.

The color luminance meter Da in the embodiment uses the measurement optical system SSa including the first and the second lens groups Gra-1 and Gra-2, and forms an intermediate image of the object Ob to be measured by the first and the second lens groups Gra-1 and Gra-2, but the color luminance meter Db in the second embodiment uses the measurement optical system SSb in which lens groups Grc form an intermediate image.

For example, as shown in fig. 1, the luminance colorimeter Db according to the second embodiment includes the optical system for measurement SSb, the light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5, and the light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5 in the luminance colorimeter Db according to the second embodiment are the same as the light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5 in the luminance colorimeter Da according to the , and therefore, the description thereof will be omitted.

For example, as shown in fig. 4, the measurement optical system SSb used in the color luminance meter Db according to the second embodiment includes an -th optical system OSb-1, a diaphragm DI, a second optical system OSb-2, and an optical waveguide OP.

Like the measurement optical system SSa of the th embodiment, the stop DI is an optical element for limiting the measurement diameter, and like the measurement optical system SSa of the th embodiment, the optical waveguide OP is an optical element for transmitting incident light, and in this embodiment, 1 enters and 3 exits the optical fiber bundle OP.

The th optical system OSb-1 is an optical element disposed on the object side (object to be measured Ob side) of the diaphragm DI, and is an optical element for forming an image of the light image of the object to be measured Ob from the object to be measured on the aperture surface of the diaphragm DI as an intermediate image, more specifically, in the present embodiment, as shown in fig. 4, the th optical system OSb-1 is composed of lens groups Grc having positive refractive power and forming an image of the light image of the object to be measured Ob from the object to be measured on the aperture surface of the diaphragm DI as an intermediate image so as to be telecentric on the object side.

The second optical system OSb-2 is an optical element disposed between the diaphragm DI and the optical waveguide OP, and is an optical element for causing each principal ray of each light flux emitted from the aperture surface of the diaphragm DI to enter the optical waveguide OP in parallel with the optical axis. That is, the second optical system OSb-2 is composed of a relay lens telecentric on the image side, and is composed of, for example, 1 lens group Grd.

As described above, the measurement optical system SSb used in the color luminance meter Db according to the second embodiment can reduce the loss of light amount due to a large incident angle of off-axis light flux, and has high light collection efficiency, similarly to the measurement optical system SSa used in the color luminance meter Da according to the .

In addition, since the th optical system OSb-1 is composed of 1 lens group Grc in the measurement optical system SSb, the configuration can be simplified.

The color luminance meter Db according to the second embodiment has the same operational effects as the color luminance meter Da according to the embodiment, because the measuring optical system SSb is used as described above.

(third embodiment)

Other embodiments will be described below. Fig. 5 is a diagram showing the configuration of a measurement optical system in the third embodiment.

, while the color luminance meters Da and Db of the second embodiment use the measurement optical systems SSa and SSb provided with the optical systems OSa-1 and OSb-1 which are telecentric on the object side, the color luminance meter Dc of the third embodiment uses the measurement optical system SSc provided with the ordinary optical system OSc-1 which is not particularly required to be telecentric on the object side.

For example, as shown in fig. 1, the color luminance meter Dc in the third embodiment includes the optical system SSc for measurement, the light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5, and the light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5 in the color luminance meter Dc in the third embodiment are the same as the light receiving unit 1, the control processing unit 2a, the input unit 3, the output unit 4, and the IF unit 5 in the color luminance meter Da in the embodiment, respectively, and therefore, the description thereof will be omitted.

For example, as shown in fig. 5, the measurement optical system SSc used in the color luminance meter Dc according to the third embodiment includes an -th optical system OSc-1, an aperture DI, a second optical system OSc-2, and an optical waveguide OP.

Like the measurement optical system SSa of the th embodiment, the diaphragm DI is an optical element for limiting the measurement diameter, and like the measurement optical system SSa of the th embodiment, the optical waveguide OP is an optical element for guiding incident light, and in this embodiment, 1 enters and 3 exits the optical fiber bundle OP.

The th optical system OSc-1 is disposed on the object side (object to be measured Ob side) of the stop DI, and is an optical element for imaging the optical image of the object to be measured Ob from the object to be measured on the aperture surface of the stop DI, more specifically, in the present embodiment, as shown in FIG. 5, the th optical system OSc-1 is constituted by 1 lens group Gre, the lens group Gre has positive refractive power and the optical image of the object to be measured Ob from the object to be measured is imaged on the aperture surface of the stop DI as an intermediate image, the lens group Gre is not necessarily particularly telecentric on the object side, and may be a normal optical system, and the th optical system OSc-1 may be constituted by a plurality of lens groups Gre, the lens group Gre has positive refractive power and the optical image of the object to be imaged on the aperture surface of the stop DI as an intermediate image.

The second optical system OSc-2 is an optical element disposed between the diaphragm DI and the optical waveguide OP, and is an optical element for causing each principal ray of each light flux emitted from the aperture surface of the diaphragm DI to enter the optical waveguide OP in parallel with the optical axis. That is, the second optical system OSc-2 is composed of a relay lens telecentric on the image side, and is composed of, for example, 1 lens group Grf.

As described above, the measurement optical system SSc used in the color luminance meter Dc according to the third embodiment can reduce the loss of light amount due to a large incident angle of off-axis light flux, and has high light collection efficiency, similarly to the measurement optical system SSa used in the color luminance meter Da according to the .

Since the measurement optical system SSc is used as described above, the color luminance meter Dc in the third embodiment has the same operational effects as the color luminance meter Da in the th embodiment.

(fourth to sixth embodiments)

Other embodiments will be described below. Fig. 6 is a block diagram showing the structure of the colorimeter in the fourth to sixth embodiments.

th to third embodiments are color luminance meters Da, Db, Dc using the measurement optical systems SSa, SSb, SSc, respectively, whereas the fourth to sixth embodiments are color meters Dd, De, Df using the measurement optical systems SSa, SSb, SSc, respectively.

For example, as shown in fig. 6, the colorimeter Dd according to the fourth embodiment includes the measuring optical system SSa, the light receiving unit 1, the control processing unit 2b, the input unit 3, the output unit 4, the IF unit 5, and the illumination unit 7, and the measuring optical system SSa, the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the colorimeter Dd according to the fourth embodiment are the same as the measuring optical system SSa, the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the color luminance meter Da according to , respectively, and therefore, description thereof will be omitted.

The illumination unit 7 is a device for irradiating the object Ob to be measured with illumination light having a predetermined geometry, and for example, the illumination unit 7 includes a light source unit that is connected to the control processing unit 2b and emits light in accordance with the control of the control processing unit 2b, and an illumination optical system that irradiates the object Ob. with the light emitted from the light source unit with the predetermined geometry as illumination light, and in fig. 6, a geometry of 45 °: 0 ° is shown as an example , but the geometry is not limited thereto and may be any.

The control processing unit 2b controls each unit of the colorimeter Dd according to the functions of the units 1, 3 to 5, and 7, and controls the entire colorimeter Dd. The control processing unit 2b measures the light from the object Ob by the measurement optical system SSa and the light receiving unit 1 in accordance with the instruction received by the input unit 3, obtains the color of the object Ob based on the electric signal output from the light receiving unit 1, and outputs the obtained color of the object Ob to the output unit 4. The control processing unit 2b outputs the obtained color of the object Ob from the IF unit 5 as necessary. In the present embodiment, the control processing unit 2b obtains the color of the object Ob from the X signal, the Y signal, and the Z signal output from the light receiving unit 1 by a known method. The control processing unit 2b is configured to include, for example, a microprocessor.

In the colorimeter Dd according to the fourth embodiment, the illumination unit 7 illuminates the object Ob with illumination light, the reflected light of which is incident on the measurement optical system ssa, and light from the object Ob (here, the reflected light) is transmitted through the measurement optical system SSa, received by the light receiving unit 1, and photoelectrically converted by the light receiving unit 1 into an X signal, a Y signal, and a Z signal, as in the embodiment, the light receiving unit 1 outputs the X signal, the Y signal, and the Z signal to the control processing unit 2b, and the control processing unit 2b obtains the color of the object Ob from the X signal, the Y signal, and the Z signal, and outputs the obtained color of the object Ob to the output unit 4.

The measurement optical system SSa used for the colorimeter Dd according to the fourth embodiment has the same operational effects as those of the embodiment, and the colorimeter Dd according to the fourth embodiment can improve the SN ratio and can measure colors with higher accuracy because of the use of the measurement optical system SSa.

For example, as shown in fig. 6, a colorimeter De according to a fifth embodiment includes a measurement optical system SSb, a light receiving unit 1, a control processing unit 2b, an input unit 3, an output unit 4, an IF unit 5, and an illumination unit 7, and the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the colorimeter De according to the fifth embodiment are the same as the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the colorimeter Da according to the , respectively, and therefore descriptions thereof are omitted, and the measurement optical system SSb in the colorimeter De according to the fifth embodiment is the same as the measurement optical system SSb in the colorimeter Db according to the second embodiment, and therefore descriptions thereof are omitted, and the control processing unit 2b and the illumination unit 7 in the colorimeter De according to the fifth embodiment are the same as the control processing unit 2b and the illumination unit 7 in the colorimeter Dd according to the fourth embodiment, respectively, and therefore descriptions thereof are omitted.

The measurement optical system SSb used in the colorimeter De in the fifth embodiment has the same operational effects as those of the second embodiment. The colorimeter De in the fifth embodiment has the same operational effects as the brightness meter Dd in the fourth embodiment by using the measuring optical system SSb as described above.

For example, as shown in fig. 6, a colorimeter Df according to a sixth embodiment includes a measuring optical system SSc, a light receiving unit 1, a control processing unit 2b, an input unit 3, an output unit 4, an IF unit 5, and an illumination unit 7, and the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the colorimeter Df according to the sixth embodiment are the same as the light receiving unit 1, the input unit 3, the output unit 4, and the IF unit 5 in the colorimeter Da according to the , respectively, and therefore description thereof is omitted, and the measuring optical system SSc in the colorimeter Df according to the sixth embodiment is the same as the measuring optical system SSc in the colorimeter Dc according to the third embodiment, and therefore description thereof is omitted, and the control processing unit 2b and the illumination unit 7 in the colorimeter Df according to the sixth embodiment are the same as the control processing unit 2b and the illumination unit 7 in the colorimeter Dd according to the fourth embodiment, respectively, and therefore description thereof is omitted.

The measurement optical system SSc used in the colorimeter Df according to the sixth embodiment has the same operational effects as those of the third embodiment. Since the measurement optical system SSa is used as described above, the colorimeter Df in the sixth embodiment has the same operational effects as the brightness colorimeter Dd in the fourth embodiment.

In the -sixth embodiment, the image-side numerical aperture NA1 of the second optical systems OSa-2, OSb-2, and OSc-2 in the measurement optical systems SSa to SSc may be equal to or larger than the numerical aperture NA2 of the optical waveguide (in the above description, the optical fiber bundle) OP (NA1 is equal to or larger than NA 2). in such measurement optical systems SSa to SSc, since NA1 is equal to or larger than NA2, part of the light emitted from the measurement optical systems SSa to SSc cannot propagate through the optical waveguide (optical fiber bundle) OP, and thus the light quantity loss occurs, but it is apparent from the above description using fig. 2C and 7B that the loss amount of the light quantity loss that occurs can be reduced as compared with the conventional case, and the measurement optical systems SSa to SSc in the above embodiment are effective when NA1 NA 2.

As described above, the present specification discloses various technical aspects, and the main technical aspects thereof are summarized as follows.

The measurement optical system according to mode includes an aperture stop, an optical waveguide that guides incident light, a th optical system that is disposed on the object side of the aperture stop and forms an optical image of a measurement target on an aperture surface of the aperture stop, and a second optical system that is disposed between the aperture stop and the optical waveguide and causes each principal ray of each light flux emitted from the aperture surface of the aperture stop to enter the optical waveguide so as to be parallel to the optical axis.

In such a measurement optical system, the th optical system forms an image of light from the object to be measured on the aperture surface of the aperture stop to form an intermediate image, and the second optical system causes the chief rays of the light beams emitted from the aperture surface of the aperture stop to enter the optical waveguide in parallel with the optical axis.

In the measurement optical system according to the , the optical system includes two lens groups, i.e., a th lens group and a second lens group, and the th and second lens groups have positive refractive power and form an image of an optical image from the measurement object on an aperture surface of the stop so as to be telecentric on the object side.

The th optical system of the above-described measuring optical system is composed of two lens groups, i.e., the th and second lens groups, and therefore, a larger amount of light can be collected, and chromatic aberration can be easily corrected as needed.

In the aforementioned measurement optical system according to another , the th optical system includes lens groups each having a positive refractive power and forming an image of light from the measurement object on an aperture surface of the stop so as to be telecentric on the object side.

The optical system for measurement as described above is less likely to be affected by unevenness of the measurement surface for reasons, and the optical system of the optical system for measurement can be configured more easily because it is configured by 1 lens group.

In the measurement optical systems according to the , the image-side numerical aperture NA1 in the second optical system is equal to or larger than the numerical aperture NA2 of the optical waveguide (NA1 ≧ NA 2).

Although such a measurement optical system generates a loss of light amount, the loss amount of the generated light amount loss can be reduced as compared with the conventional system.

The color luminance meter according to the mode uses any types of the above-described measuring optical systems.

The color luminance meter as described above can conduct a larger amount of light from the object to be measured to the light receiving portion by using any of the types of optical systems for measurement, and therefore, the color luminance meter can improve the SN ratio (Signal-to-Noise ratio) and can measure color with higher accuracy.

The colorimeter according to the mode uses any types of the above-described measuring optical systems.

The colorimeter as described above uses any of the measurement optical systems, and therefore, can transmit a larger amount of light from the object to be measured to the light receiving portion.

The application is proposed based on Japanese patent application laid-open at 2017, 6, and 15, and the content of the Japanese patent application laid-open at 2017, 117588 is included in the application.

The embodiments of the present invention have been illustrated and described in detail, but the embodiments are merely illustrative and examples, and are not restrictive. The scope of the invention should be construed in accordance with the recitation of the appended claims.

In the above description, is referred to in the drawings, describes the present invention properly and sufficiently in terms of embodiments, but it should be understood that a person skilled in the art can easily make changes and/or improvements to the above embodiments to express the present invention.

Industrial applicability of the invention

According to the present invention, it is possible to provide a measurement optical system that transmits light from a measurement object to a light receiving unit, a luminance colorimeter using the measurement optical system, and a colorimeter using the measurement optical system.