JP2016095277A - Optical property measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical property measurement device capable of providing further accurate measurement of optical properties of an object under measurement even when the object under measurement has a polarizing property or directivity.SOLUTION: An optical property measurement device D1 includes: an imaging optical system 6 that outputs measurement light rays L for forming an image of an object under measurement; a bifurcating mirror 5 that splits the measurement light rays L into transmitted light rays L0 and reflected light rays L1 and splits an optical axis AX of the imaging optical system 6 into a transmission optical axis AX0 on a side of the transmitted light rays L0 and a reflection optical axis AX1 on a side of the reflected light rays L1; a line sensor 14 disposed on the transmission optical axis AX0; and a two-dimensional sensor 22 disposed on the reflection optical axis AX1. The bifurcating mirror 5 has transmissive areas A0 that allow the measurement light rays L to pass through and reflective areas A1 that reflect the measurement light rays L, where both the transmissive areas A0 and reflective areas A1 receive both a portion of the measurement light rays L in a light ray central area Aa centered on the optical axis AX and a portion thereof in a light ray peripheral area Ab that surrounds the light ray central area Aa.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical characteristic measuring apparatus. For example, the present invention relates to an optical characteristic measuring apparatus that measures predetermined optical characteristics such as luminance, color, and gloss, and more accurate even when the object to be measured has polarization characteristics or viewing angle characteristics (directivity). The present invention relates to an optical characteristic measuring apparatus capable of good measurement.

  In recent years, in various industrial fields such as painting, molding, printing, textiles, agriculture, etc., management of predetermined optical characteristics such as brightness, color, luster, etc. of products (for example, brightness and color of display monitors and automobile instrument panels) has been managed. It is becoming important. As the apparatus for measuring the predetermined optical characteristics, for example, optical characteristic measuring apparatuses such as a luminance meter, a spectrocolorimeter, a color meter (color and color difference meter), a gloss meter, and the like are known. There are two-dimensional colorimeters disclosed in Patent Documents 1 and 2.

  The two-dimensional colorimeter disclosed in Patent Documents 1 and 2 includes a beam splitter that branches light from a sample into a first optical path and a second optical path, and light guided to the first optical path passes therethrough. First, second, and third optical filters that are arranged at positions where the spectral transmittance approximates the color matching function of a predetermined three-dimensional color system, and the first, second, and third optical filters A two-dimensional light receiving detection means for receiving the light passing through each of the plurality of measurement points on the sample surface, and a spectrum for detecting a spectral distribution of the light guided to the second optical path from a specific point among the measurement points. Detection means; tristimulus value calculation means for calculating tristimulus values of the three-dimensional color system based on the detected spectral distribution; and the two-dimensional light reception detection at the calculated tristimulus values and the specific point. The above other than the specific point using the relationship with the detection result of the means And a calculating means for calculating the tristimulus values from the detection results of the two-dimensional light receiving detection means for fixed point.

  The two-dimensional colorimeter is configured by combining a two-dimensional color luminance meter and a spectrometer. Then, using the relationship between the tristimulus value and the detection result of the two-dimensional light reception detection unit at the specific point, the calculation unit calculates the tristimulus value from the detection result of the two-dimensional light reception detection unit at a measurement point other than the specific point. Thus, it is possible to correct the detection result of the two-dimensional light receiving detection means with relatively low accuracy with the tristimulus values with relatively high accuracy. Therefore, it is possible to accurately measure the color of measurement points other than the specific point with a simple configuration.

Japanese Patent No. 3246021 JP-A-6-201472

  In the two-dimensional colorimeters disclosed in Patent Documents 1 and 2, it is fundamental that the same light from the same location is branched into two and measured by different methods. However, there is a problem in the branching method for obtaining the same light, and here, the identity regarding the polarization and the radiation direction becomes a problem.

  First, regarding polarized light, a problem when the light from the sample has polarization characteristics (that is, when the ratio of P-polarized light and S-polarized light is different) will be described. When the beam splitter is used to branch the light from the sample into the first optical path and the second optical path as in the two-dimensional colorimeter disclosed in Patent Documents 1 and 2, when the beam splitter is used, Since the half mirror has a large polarization dependency (S-polarized light reflectance> P-polarized light reflectance, S-polarized light transmittance <P-polarized light transmittance), the case where the beam splitter is at the position of P-polarized light with respect to the sample light and S-polarized light In this case, the relationship between the amount of light transmitted and reflected differs, and correct measurement cannot be performed.

Hereinafter, a specific example of the polarization dependence at a wavelength of 500 nm and 45 ° incidence will be shown.
Aluminum:
Reflection S-polarized light 94%, P-polarized light 89%, Average reflectance 91.5%, Polarization dependence 2.7%
Half mirror:
Reflection S-polarized light 90%, P-polarized light 10%, average reflectance 50%, polarization dependence 80%
Transmission S-polarized light 10%, P-polarized light 90%, Average transmittance 50%, Polarization dependence -80%
Glass:
Reflection S-polarized light 9%, P-polarized light 1%, average reflectance 5%, polarization dependence 80%
Transmission S-polarized light 91%, P-polarized light 99%, Average transmittance 95%, Polarization dependence -4.2%
Glass with single-layer reflective film:
Reflection S-polarized light 3.9%, P-polarized light 0.1%, Average reflectance 2%, Polarization dependence 95%
Transmission S-polarized light 96.1%, P-polarized light 99.9%, Average transmittance 98%, Polarization dependence -0.4%

  Next, the problem in the case where the light from the sample has directivity in the radiation direction (that is, the amount of light and chromaticity are biased in the radiation direction (viewing angle)) will be described. For example, a liquid crystal display panel has a different light quantity and chromaticity between the front and the other. When measurement is performed with the colorimeter placed in front of the liquid crystal display panel, the optical system of the colorimeter guides light from the sample with an angle to the light receiver. The amount of light and chromaticity are different between the light and the light in the peripheral region of the light beam positioned around it. Therefore, a substantially circular or elliptical mirror is arranged in the central region of the light beam, or a substantially circular mirror having a mirror surface in the peripheral region of the light beam is arranged to reflect the light beam at a part of the mirror surface, and the mirror surface It is conceivable to take measures to split the light beam by passing (transmitting) the light beam in a portion where there is no light. However, if the two light beams obtained by the branching are received by the two light receivers, both light beams have different light amounts and chromaticities, so both light receivers will perform different light amount measurements and chromaticity measurements, It will not be possible to measure correctly.

Below, the specific example (directivity example) of the radiation angle dependence of a liquid crystal display panel is shown.
VA (vertical alignment) mode panel, chromaticity variation with respect to the front:
± 5 ° Δxy = 0.0013,
± 10 ° Δxy = 0.0019

  In addition, in a colorimeter that uses a tristimulus detector instead of the spectral detection means, one end face of the bundle fiber is arranged in the vicinity of the imaging position, and the other end face is divided to divide the received light into three filters. Although it is arranged to emit light to the filter, the sample surface has variations in brightness and chromaticity depending on the position (nonuniformity inherent to the sample and nonuniformity due to dust and dirt adhering to the sample). The measurement value becomes unstable due to the positional deviation at the time of measurement, and the measurement accuracy is lowered. If the end face of the bundle fiber is arranged at the defocus position, the variation is averaged and the measurement value is stabilized. However, for sufficient averaging, the light flux center region centered on the optical axis is extended to the light beam peripheral region. It is necessary to include rays of various angles.

  The present invention has been made in view of the circumstances as described above, and its purpose is to measure the optical characteristics of the object to be measured with higher accuracy even when the object to be measured has polarization characteristics or directivity. An object of the present invention is to provide an optical property measuring apparatus that can be used.

In order to achieve the above object, an optical characteristic measurement apparatus according to a first aspect of the present invention includes an imaging optical system that emits a measurement light beam for forming an image of an object to be measured;
A branch mirror that divides the measurement light beam into a transmitted light beam and a reflected light beam, and divides the optical axis of the imaging optical system into a transmitted light axis on the transmitted light beam side and a reflected optical axis on the reflected light beam side;
A first sensor disposed on the transmitted optical axis;
A second sensor disposed on the reflected optical axis;
An optical characteristic measuring device comprising:
One of the first and second sensors is a colorimetric sensor, and the other is a two-dimensional color image sensor,
The branch mirror has a transmission region that transmits the measurement light beam and a reflection region that reflects the measurement light beam;
Both the transmission region and the reflection region are formed so as to receive both the light in the central region of the light beam centered on the optical axis and the light in the peripheral region of the light beam positioned around the light beam in the measurement light beam. It is characterized by that.

  The optical characteristic measuring apparatus according to a second aspect of the present invention is the optical characteristic measuring apparatus according to the first aspect, wherein the boundary between the light flux center region and the light flux peripheral region is one half of the distance from the optical axis to the outermost edge in the measurement light flux. It is in position.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the transmission region and the reflection region are alternately positioned with a radial line centered on the optical axis as a boundary. Features.

  The optical characteristic measuring apparatus according to a fourth invention is characterized in that, in the first or second invention, the transmission region and the reflection region are alternately arranged in a grid-like stripe pattern. To do.

  The optical property measuring apparatus according to a fifth aspect of the invention is characterized in that, in the first or second aspect of the invention, the transmissive areas and the reflective areas are arranged in a mosaic pattern in a square checkered pattern and are alternately positioned. To do.

  In the optical characteristic measuring apparatus according to a sixth aspect of the present invention, in any one of the first to fifth aspects, an area ratio between the transmission region and the reflection region is 1: 9 to 5: 5. And

  An optical property measuring apparatus according to a seventh invention is the optical property measuring apparatus according to any one of the first to sixth inventions, wherein the branch mirror is provided with the reflective region by forming a reflective film on a transparent flat plate surface. It is characterized by being.

  An optical characteristic measuring apparatus according to an eighth invention is the optical property measuring apparatus according to any one of the first to sixth inventions, wherein the branch mirror is provided with the reflection region by disposing a minute mirror on a virtual plane. It is characterized by being.

An optical characteristic measuring apparatus according to a ninth aspect of the present invention includes the colorimetric sensor according to any one of the first to eighth aspects, wherein the optical characteristic measuring apparatus is a first unit that spectroscopically measures the measurement light beam with a first accuracy. A spectroscopic measurement unit, and a second spectroscopic measurement unit that has the two-dimensional color imaging device and that splits and measures the measurement light beam with a second accuracy.
The first accuracy is higher than the second accuracy.

  According to the optical property measuring apparatus of the present invention, it is possible to measure the optical property of the object to be measured with higher accuracy even when the object to be measured has polarization characteristics or directivity.

1 is a schematic configuration diagram showing a first embodiment of an optical characteristic measuring apparatus. The schematic block diagram which shows 2nd Embodiment of an optical characteristic measuring apparatus. The schematic block diagram which shows 3rd Embodiment of an optical characteristic measuring apparatus. The top view which shows the specific example 1 of a branch mirror. The top view which shows the specific example 2 of a branch mirror. The top view which shows the specific example 3 of a branch mirror. The top view which shows the specific example 4 of a branch mirror. The top view which shows the specific example 5 of a branch mirror. The graph which shows the specific example 1 of the spectral response degree of an optical filter. The graph which shows the specific example 2 of the spectral response degree of an optical filter. The graph which shows the specific example 3 of the spectral response degree of an optical filter.

  Hereinafter, an optical characteristic measuring apparatus and the like embodying the present invention will be described with reference to the drawings. Note that the same or corresponding parts in the embodiment, specific examples, and the like are denoted by the same reference numerals, and redundant description is omitted as appropriate.

  FIG. 1 shows a first embodiment of the optical property measuring device D1, FIG. 2 shows a second embodiment of the optical property measuring device D2, and FIG. 3 shows a third embodiment of the optical property measuring device D3. The form is shown. 1 and 2 includes a first spectroscopic measurement unit 1, a second spectroscopic measurement unit 2, a variable measurement angle optical system 3, a control processing unit 4, a branch mirror 5, an imaging optical system 6, An input / output unit 8 and a storage unit 9 are provided. 3 includes a first spectroscopic measurement unit 1A, a second spectroscopic measurement unit 2A, a control processing unit 4, a branch mirror 5, an imaging optical system 6, an input / output unit 8, and a storage unit 9. Etc.

  In the optical characteristic measurement apparatus D1, the reflected light beam L1 from the branch mirror 5 enters the first spectroscopic measurement unit 1, and the transmitted light beam L0 from the branch mirror 5 enters the measurement angle variable optical system 3 and the second spectroscopic measurement unit 2. To do. On the other hand, in the optical characteristic measuring apparatus D2, the transmitted light beam L0 from the branch mirror 5 enters the first spectroscopic measurement unit 1, and the reflected light beam L1 from the branch mirror 5 is measured by the variable measuring angle optical system 3 and the second spectroscopic measurement unit. 2 is incident. As described above, the optical characteristic measuring device D1 and the optical characteristic measuring device D2 have the same configuration except that the constituent elements to which the transmitted light beam L0 and the reflected light beam L1 are incident are interchanged. It is.

  In the optical characteristic measuring apparatus D3, the transmitted light beam L0 from the branch mirror 5 enters the first spectroscopic measurement unit 1A, and the reflected light beam L1 from the branch mirror 5 enters the second spectroscopic measurement unit 2A. As described above, the optical property measuring apparatus D3 includes the first spectroscopic measurement unit 1A instead of the first spectroscopic measurement unit 1, and the second spectroscopic measurement unit 2A instead of the measurement angle variable optical system 3 and the second spectroscopic measurement unit 2. In addition to the above, since the optical characteristic measuring device D2 has the same configuration, the effects obtained thereby are also the same. Regarding the first and second spectroscopic measurement units 1A and 2A, as will be described later, the first spectroscopic measurement unit 1A is a tristimulus photometer, and the second spectroscopic measurement unit 2A is a two-dimensional photodetection detector. .

  In the optical characteristic measuring devices D1 to D3, the imaging optical system 6 includes a light receiving lens system 6a and an aperture stop 6b, and emits a measurement light beam L for forming an image of the object to be measured. The light to be measured from the measurement object to be measured is emitted from the measurement region SP and enters the light receiving lens system 6a. The light receiving lens system 6a corresponds to an objective lens composed of an optical element such as one or a plurality of optical lenses. Here, the light receiving lens system 6a is composed of a cemented lens of a biconvex positive lens and a negative meniscus lens convex on the image side. And has a positive refractive power (optical power defined by the reciprocal of the focal length) as a whole. The light to be measured incident on the light receiving lens system 6a is converged, and an image (first image) IM1 to be measured is formed at a predetermined position P1 and its equivalent position P3 via the aperture stop 6b and the branch mirror 5, respectively. Is done. In addition, when the light source to be measured is arranged in the measurement area SP, the measurement light may be light emitted from the light source (light of the light source itself), or the measurement area SP may be measured. When an object is arranged, it may be reflected light generated by reflecting light emitted from a predetermined light source by the object to be measured.

  The aperture stop 6b is disposed at a predetermined position near the branch mirror 5 between the light receiving lens system 6a and the branch mirror 5. The aperture stop 6b is an optical member that regulates the size of the measurement light beam L (for example, the light beam diameter) emitted from the imaging optical system 6 by allowing the light to be measured to pass while restricting the light beam. For example, it is a plate-like member made of a material having a light shielding property with respect to the wavelength range of the light to be measured and having a through hole for allowing the light to be measured to pass therethrough. The size of the through hole is set according to the size of the measurement light beam L that passes through the aperture stop 6b.

  The branch mirror 5 is disposed in the measurement light beam L of the light to be measured, divides the measurement light beam L into a transmitted light beam L0 and a reflected light beam L1, and transmits the optical axis AX of the imaging optical system 6 to the transmitted light on the transmitted light beam L0 side. It is divided into an axis AX0 and a reflected optical axis AX1 on the reflected light beam L1 side. Therefore, the measurement light beam L is divided into a reflected light beam L1 whose optical path is bent by reflection at the branch mirror 5, and a transmitted light beam L0 which is transmitted without being bent at the branch mirror 5. A first sensor is disposed on the transmitted optical axis AX0, and a second sensor is disposed on the reflected optical axis AX1. In the optical characteristic measuring devices D1 and D2 (FIGS. 1 and 2), one of the first and second sensors is a line sensor 14 (colorimetric sensor), and the other is a two-dimensional sensor 22 (two-dimensional color). Imaging device). In the optical characteristic measuring device D3 (FIG. 3), the first to third sensors S1 to S3 are arranged on the transmission optical axis AX0, and the two-dimensional sensor (not shown) is arranged on the reflection optical axis AX1.

  In the optical characteristic measuring apparatus D1 (FIG. 1), the reflected light beam L1 is guided to the first spectroscopic measurement unit 1, and the transmitted light beam L0 is guided to the measurement angle variable optical system 3 and the second spectroscopic measurement unit 2. In the optical characteristic measuring device D2 (FIG. 2), the transmitted light beam L0 is guided to the first spectroscopic measurement unit 1, and the reflected light beam L1 is guided to the measurement angle variable optical system 3 and the second spectroscopic measurement unit 2. In the optical characteristic measuring device D3 (FIG. 3), the transmitted light beam L0 is guided to the first spectroscopic measurement unit 1A, and the reflected light beam L1 is guided to the second spectroscopic measurement unit 2A. Then, in the optical characteristic measuring devices D1 to D3 (FIGS. 1 to 3), both the transmitted light beam L0 and the reflected light beam L1 are transmitted to and around the light in the central region of the light beam L centered on the optical axis AX. It includes both of the light in the surrounding region of the luminous flux. 1 to 3, an example of a light beam on the boundary between the light flux center region and the light flux peripheral region is indicated by a dotted line. A specific example of the branch mirror 5 will be described later in detail (FIGS. 4 to 8).

  The first and second spectroscopic measurement units 1, 1 </ b> A; 2, 2 </ b> A are respectively connected to the control processing unit 4, and the measurement light beam L (that is, the reflected light beam L <b> 1 and the transmitted light beam L <b> 0) is controlled under the control of the control processing unit 4. Spectroscopically measure. In the optical property measuring apparatus D1 (FIG. 1), the first spectroscopic measurement unit 1 measures the reflected light beam L1 by spectroscopically measuring with the first accuracy, and outputs the measurement result (first spectroscopic measurement result) to the control processing unit 4. . The second spectroscopic measurement unit 2 spectroscopically measures the transmitted light beam L0 with the second accuracy and outputs the measurement result (second spectroscopic measurement result) to the control processing unit 4. In the optical characteristic measurement devices D2 and D3 (FIGS. 2 and 3), the first spectroscopic measurement units 1 and 1A measure the transmitted light beam L0 with the first accuracy and measure the measurement result (first spectroscopic measurement result). Output to the control processing unit 4. The second spectroscopic measurement units 2 and 2 </ b> A measure and measure the reflected light beam L <b> 1 with the second accuracy and output the measurement result (second spectroscopic measurement result) to the control processing unit 4.

  The first and second spectroscopic measurement units 1, 1A; 2, 2A have different measurement accuracy. That is, the first accuracy of the first spectroscopic measurement units 1 and 1A is higher than the second accuracy of the second spectroscopic measurement units 2 and 2A. That is, the first spectroscopic measurement units 1 and 1A have higher accuracy than the second spectroscopic measurement units 2 and 2A.

  The first spectroscopic measurement unit 1 of the optical characteristic measurement devices D1 and D2 (FIGS. 1 and 2) is a device that performs spot measurement (single-point measurement), and measures the measurement light beam L that is light to be measured as one point. One first spectroscopic measurement result is output. Then, the measurement light beam L radiated from a relatively narrow measurement area SP (for example, a range in which the first spectroscopic measurement angle is about 0.1 ° to about 3 °) is measured. That is, in the first spectroscopic measurement unit 1, measurement is performed in which the measurement light beam L (the reflected light beam L1 or the transmitted light beam L0) is treated as one regardless of the radiation position of the measurement light beam L.

  The first spectroscopic measurement unit 1 (FIGS. 1 and 2), which is mentioned here as an example, is a spectrophotometer that measures and measures a measurement light beam L at a predetermined wavelength interval with a spectroscopic optical element such as a diffraction grating. The spectroscopic first spectroscopic measurement unit 1 accommodates a lens system 12, a reflective diffraction grating 13, a line sensor 14 as a colorimetric sensor, and the lens system 12, the reflective diffraction grating 13 and the line sensor 14. And a housing 10 to be operated. The housing 10 is a box formed of a material having a light shielding property with respect to a wavelength range in which the line sensor 14 can receive light. An incident opening 11 having a slit shape or the like for guiding the reflected light beam L1 or the transmitted light beam L0, which is a part of the light to be measured, into the housing 10 is formed on one side surface of the housing 10. The first spectroscopic measurement unit 1 is arranged such that the incident aperture 11 is located at a convergence position P3 (an equivalent position of the position P1) where the first image IM1 is formed.

  The reflected light beam L1 (FIG. 1) or the transmitted light beam L0 (FIG. 2) incident from the incident aperture 11 is incident on the lens system 12, collimated by the lens system 12, and incident on the reflective diffraction grating 13. The light is diffracted and reflected by the reflective diffraction grating 13. The reflected light is incident on the lens system 12 again, and is formed on the light receiving surface of the line sensor 14 as a wavelength dispersion image of the optical image by the lens system 12. The line sensor 14 has a configuration including a plurality of photoelectric conversion elements arranged along one direction. This photoelectric conversion element is, for example, a silicon photodiode (SPD). The line sensor 14 generates an electrical signal representing an intensity level for each wavelength by photoelectrically converting the wavelength dispersion image of the optical image formed on the light receiving surface by each of the plurality of photoelectric conversion elements. Then, the line sensor 14 outputs this electric signal (first spectroscopic measurement result) to the control processing unit 4.

  The first spectroscopic measurement unit 1A of the optical characteristic measurement device D3 (FIG. 3) is a tristimulus type photometer, and a bundle fiber FB that divides the transmitted optical axis AX0 (transmitted light beam L0) into three and spectral responses different from each other. First to third optical filters F1, F2, and F3 having the same degree, and first to third sensors S1, S2, and S3 that receive light that has passed through the first to third optical filters F1, F2, and F3. And. Each of the first to third optical filters F1 to F3 has a spectral response (specific example 1) approximated to a CIE (International Commission on Illumination) color matching function, for example, as shown in FIG. That is, the first optical filter F1 has a spectral response close to the CIE color matching function z (λ), and the second optical filter F2 has a spectral response close to the CIE color matching function y (λ). The third optical filter F3 has a spectral response approximate to the CIE color matching function x (λ) (λ: wavelength). Or these 1st-3rd optical filters F1-F3 may each have the spectral response (specific example 2) shown, for example in FIG.

  The light that has passed through the first to third optical filters F1 to F3 is applied to the first to third sensors S1 to S3 (for example, silicon photodiode (SPD)). The first to third sensors S <b> 1 to S <b> 3 generate photoelectric signals representing the intensity levels for the respective spectral responsiveness levels by performing photoelectric conversion, and output them to the control processing unit 4.

  The second spectroscopic measurement unit 2 of the optical characteristic measurement devices D1 and D2 (FIGS. 1 and 2) is a device that performs two-dimensional measurement, measures two-dimensionally with a measurement light beam L that is light to be measured as a surface, and 2 The second spectroscopic measurement result of the dimensional distribution is output. Then, the measurement light beam L radiated from a relatively wide measurement area SP (for example, a range in which the second spectroscopic measurement angle is about 10 ° to about 30 °) is measured. That is, the second spectroscopic measurement unit 2 measures an optical characteristic distribution for measuring the measurement light beam L (the reflected light beam L1 or the transmitted light beam L0) for each radiation position of the measurement light beam L.

  The second spectroscopic measurement unit 2 (FIGS. 1 and 2) given here as an example is a photometer that measures and measures the measurement light beam L in a predetermined wavelength range with an optical filter or the like. The second spectroscopic measurement unit 2 includes a filter selection unit 21 (for example, a color wheel) and a two-dimensional sensor (area sensor) 22 constituting a two-dimensional color image sensor. The two-dimensional sensor 22 is disposed so that the light receiving surface is positioned at the image formation position P2 where the second image IM2 is formed. The filter selection unit 21 includes a plurality of optical filters 211, a filter holding member 212 that holds the plurality of optical filters 211, and a motor 213 that generates a driving force for moving the filter holding member 212. This is a device that selects one optical filter 211 to be used for filtering measured light from among a plurality of optical filters 211.

  The filter holding member 212 is, for example, a disc in which four through openings are formed at equal intervals in the circumferential direction. These four through-openings are formed in a size corresponding to three optical filters 211 (B and G are shown in FIG. 1 and FIG. 2) corresponding to RGB, of which Three optical filters 211 are fitted in the three through openings, respectively, and are fixedly bonded with, for example, an adhesive.

  In addition, the filter holding member 212 has a rotation shaft inserted in the center position thereof, and gear cutting is performed on the peripheral surface thereof to form a gear. The gear of the filter holding member 212 is engaged with a gear mounted on the output shaft of the motor 213 so that the driving force of the motor 213 is transmitted to the filter holding member 212. Accordingly, the filter holding member 212 is driven to rotate about the rotation axis. The filter holding member 212 is a measurement angle variable optical system so that the optical axis AX0 or the optical axis AX1 coincides with the optical axis AX1 in the second spectroscopic measurement unit 2 each time the optical axes of the three optical filters 211 are sequentially rotated. 3 and the two-dimensional sensor 22.

  The second spectroscopic measurement unit 2A of the optical characteristic measurement device D3 (FIG. 3) is a two-dimensional light receiving device that performs two-dimensional measurement, like the second spectroscopic measurement unit 2 of the optical characteristic measurement devices D1 and D2 (FIGS. 1 and 2). It is a detection device, and measures the measurement light beam L, which is the light to be measured, in a two-dimensional manner, and outputs a second spectroscopic measurement result of a two-dimensional distribution. Then, the measurement light beam L radiated from a relatively wide measurement area SP (for example, a range in which the second spectroscopic measurement angle is about 10 ° to about 30 °) is measured. That is, the second spectroscopic measurement unit 2 measures an optical characteristic distribution for measuring the measurement light beam L (the reflected light beam L1 or the transmitted light beam L0) for each radiation position of the measurement light beam L.

  As such a second spectroscopic measurement unit 2A, for example, a photometer that measures and measures the measurement light beam L in a predetermined wavelength range with an optical filter or the like, more specifically, a single plate type two-dimensional having a color filter array. A color imaging device or the like can be given. However, the filter (not shown) in front of the two-dimensional sensor (not shown) constituting the two-dimensional color imaging device in the second spectroscopic measurement unit 2A is inferior to the first spectroscopic measurement unit filter in CIE color matching function approximation. For example, it has the spectral response (specific example 3) shown in FIG.

  In the second spectroscopic measurement units 2 and 2A of the optical characteristic measuring apparatuses D1 to D3 (FIGS. 1 to 3), three types of optical filters having different spectral responsiveness are, for example, as shown in FIG. Illumination Committee) Each has a spectral response (specific example 1) approximated to a color matching function. That is, the first optical filter has a spectral response approximating the CIE color matching function z (λ), the second optical filter has a spectral response approximating the CIE color matching function y (λ), and The third optical filter has a spectral response approximate to the CIE color matching function x (λ). Alternatively, these first to third optical filters may each have the spectral response (specific examples 2 and 3) shown in FIGS. 10 and 11, for example. In the second spectroscopic measurement units 2 and 2A, the optical filter may be arranged in front of the two-dimensional sensor or may be arranged just before each cell of the two-dimensional sensor.

  As described above, in the optical characteristic measurement apparatuses D1 to D3 (FIGS. 1 to 3), both the transmitted light beam L0 and the reflected light beam L1 are the light in the central region of the light beam L centered on the optical axis AX. It includes both the light in the peripheral region of the light beam located around it. In order to divide the measurement light beam L in this way, the branch mirror 5 has a transmission region that transmits the measurement light beam L and a reflection region that reflects the measurement light beam L. Both are formed so as to receive both the light in the central region of the light beam centered on the optical axis AX and the light in the peripheral region of the light beam positioned around it in the measurement light beam L.

  The reflective region that reflects the measurement light beam L in the branch mirror 5 is configured by a reflective surface using a metal material such as aluminum as a reflective material, for example. For example, a reflective region may be provided by forming a reflective film made of a metal material such as aluminum on the surface of a transparent flat plate, or a reflective region may be provided by arranging a micromirror made of a metal material such as aluminum on a virtual plane. May be. The transmission region through which the measurement light beam L is transmitted in the branch mirror 5 is configured by setting a range where the reflection surface is not provided as a transmission surface. For example, a transmissive region may be provided by not forming a reflective film made of a metal material such as aluminum on the surface of the transparent flat plate, and a transmissive region may be provided by not arranging a micromirror made of a metal material such as aluminum on a virtual plane. May be.

  Since the half mirror as a beam splitter has a large polarization dependency as described above, the light quantity relationship between transmission and reflection when the beam splitter is at the P-polarization position and at the S-polarization position with respect to the sample light. Will not be able to measure correctly. As described above, the branch mirror 5 having the transmission region that transmits the measurement light beam L and the reflection region that reflects the measurement light beam L has a small polarization dependence, so that the object to be measured has polarization characteristics. Even in this case, the optical characteristics of the object to be measured can be measured with higher accuracy.

  Further, when various samples are assumed as the object to be measured, if the light from the sample has directivity as described above, correct measurement cannot be performed. A specific example of the branch mirror 5 capable of performing light beam splitting suitable for the directivity countermeasure will be described below.

  4 to 8 show branch mirrors 5 a to 5 e as specific examples 1 to 5 of the branch mirror 5. The branch mirrors 5a to 5e have a transmission region A0 that transmits the measurement light beam L (FIGS. 1 to 3) and a reflection region A1 that reflects the measurement light beam L. Either of the transmission region A0 or the reflection region A1 However, in the measurement light beam L, both the light in the light beam center region Aa (circular region) centered on the optical axis AX and the light in the light beam peripheral region Ab (ring-shaped region including the outermost edge of the light beam) positioned around the light beam Both are formed to receive light. The reflective area A1 is made of a reflective film or a mirror, and the transmissive area A0 is made of a transparent material or space. The branch mirrors 5a to 5e are arranged on a virtual plane that is oblique (generally 45 °) with respect to the measurement light beam L, so that the measurement light beam L is separated into the transmitted light beam L0 and the reflected light beam L1. The

  Here, the boundary (dotted line) between the light flux center area Aa and the light flux peripheral area Ab is set at a position that is half the distance from the optical axis AX to the outermost edge in the measurement light flux L. From this, it can be seen that both the transmitted light beam L0 and the reflected light beam L1 in FIGS. 1 to 3 include both the light in the light beam central region Aa and the light in the light beam peripheral region Ab. As described above, both the transmission area A0 and the reflection area A1 are formed so as to receive both the light in the light flux center area Aa centered on the optical axis AX and the light in the light flux peripheral area Ab positioned around the light transmission area A0. This makes it difficult to be affected by the viewing angle characteristics (directivity) of the object to be measured, so that even if the object to be measured has directivity, the optical characteristics of the object to be measured can be measured more accurately. Can do.

  The branch mirrors 5a to 5c (FIGS. 4 to 6) are configured such that the transmission regions A0 and the reflection regions A1 are alternately positioned with a radial line centered on the optical axis AX as a boundary. That is, in this example, the surfaces of the branch mirrors 5a to 5c are divided radially from the optical axis AX corresponding to the center of the mirror, and the transmissive areas A0 and the reflective areas A1 are alternately arranged. In the case of the branch mirrors 5a and 5b (FIGS. 4 and 5), since the light flux center area Aa and the light flux peripheral area Ab are included in the transmission area A0 and the reflection area A1 in the vertical and horizontal directions, the measurement light flux L is the optical axis AX. When having directivity symmetrically in the vertical and horizontal directions with respect to the center, the transmitted light beam L0 and the reflected light beam L1 exhibit the same luminance and chromaticity with respect to the first and second spectroscopic measurement units 1, 1A; It will be. Since the branch mirror 5b (FIG. 5) is concentrically divided, the branch mirror 5b (FIG. 6) is suitable when it has directivity asymmetrically in the vertical and horizontal directions, and the branch mirror 5c (FIG. 6) is arranged in the circumferential direction. Since the number of divisions is increased, it is suitable for the case where the directivity is symmetrical in the diagonal direction in the vertical and horizontal directions.

  The branch mirror 5d (FIG. 7) has a configuration in which the transmission regions A0 and the reflection regions A1 are alternately arranged in a grid-like striped pattern. That is, this is an example of division in which the surface of the branch mirror 5d is divided into a striped lattice pattern, and the transmission areas A0 and the reflection areas A1 are alternately arranged. This branching mirror 5d is suitable for a case where the left and right asymmetrical directivity is provided.

  The branch mirror 5e (FIG. 8) has a configuration in which the transmissive areas A0 and the reflective areas A1 are arranged in a mosaic pattern in a square checkered pattern and are alternately positioned. That is, in this example, the surface of the branch mirror 5e is divided into a checkered quadrangular shape, and the transmission areas A0 and the reflection areas A1 are alternately arranged. This branch mirror 5e is suitable when it has directivity in various directions.

  For example, when the measurement light beam L is divided into a large number of four or more transmitted light beams L0 and reflected light beams L1 by the branch mirrors 5d and 5e (FIGS. 7 and 8), a reflective film is formed on the surface of the transparent flat plate to form a reflective region. If A1 is provided, the reflective film can be formed by patterning, so that it can be easily configured with a small number of components. In addition, you may arrange | position a micromirror on a transparent flat plate surface instead of a reflecting film.

  The transmission region A0 and the reflection region A1 of the branch mirrors 5a to 5e (FIGS. 4 to 8) can be formed by arranging a plurality of minute mirrors on a virtual plane. Since an optical medium such as glass does not exist in a portion where there is no micromirror on the virtual plane, the measurement light beam L passes through the branch mirrors 5a to 5e without being affected by the polarization property of the optical medium. As will be described later, when correcting a low-precision detection result with a high-precision detection result, it is suitable to provide a high-precision detector on the side that receives the transmitted light beam L0 in order to obtain high accuracy. .

  When a reflective film is formed on the transparent flat plate surface, the area ratio between the transmission region A0 and the reflection region A1 is set to 5: 5 to 6: 4 in consideration of the ratio between the transmittance and the reflectance of the transparent flat plate. preferable. When a micromirror is arranged on a virtual plane, it is preferable that the area ratio between the transmission region A0 and the reflection region A1 is 4: 6 to 5: 5 in consideration of the mirror reflectivity. With these configurations, the light quantity ratios for the first spectroscopic measurement units 1 and 1A and the second spectroscopic measurement units 2 and 2A can be made the same.

  Further, in the configuration in which a plurality of micromirrors are arranged on a virtual plane, when the two-dimensional measurement is performed with the reflected light beam L1 as in the optical characteristic measurement devices D2 and D3 (FIGS. 2 and 3), the two-dimensional light receiving means is low. The luminance performance is often inferior to about an order of magnitude compared to the spectral detection (colorimetry) means. For this reason, it is desirable that the area ratio between the transmission region A0 and the reflection region A1 is 1: 9 to 5: 5. In view of the above, the area ratio between the transmission region A0 and the reflection region A1 is preferably 1: 9 to 6: 4.

  As described above, the branch mirror 5 has the transmission region A0 that transmits the measurement light beam L and the reflection region A1 that reflects the measurement light beam L. Therefore, the branch mirror 5 is not easily affected by the polarization characteristics of the object to be measured. Each of the transmission area A0 and the reflection area A1 is formed so as to receive both the light in the light flux center area Aa centered on the optical axis AX and the light in the light flux peripheral area Ab positioned therearound. Therefore, it is difficult to be affected by the viewing angle characteristics (directivity) of the object to be measured. Therefore, according to the optical characteristic measuring devices D1 to D3 (FIGS. 1 to 3), even when the measured object has polarization characteristics or directivity, the optical characteristic of the measured object can be measured with higher accuracy. Is possible.

  In the optical characteristic measuring devices D1 to D3 (FIGS. 1 to 3), the control processing unit 4 includes an input / output unit 8 including an input unit 81, an output unit 82, an IF (interface) unit 83, a storage unit 9, and the like. , Is connected. The storage unit 9 is a circuit that stores various predetermined programs and various predetermined data under the control of the control processing unit 4. The various predetermined programs include, for example, a control processing program such as a measurement program for measuring the light to be measured. The various predetermined data includes a correction coefficient obtained by a correction calculation unit 422 described later. The storage unit 9 includes, for example, a ROM (Read Only Memory) that is a nonvolatile storage element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable nonvolatile storage element, and the like. The storage unit 9 includes a RAM (Random Access Memory) serving as a working memory of the so-called control processing unit 4 that stores data and the like generated during execution of the predetermined program.

  The control processing unit 4 is a circuit for controlling the respective units of the optical characteristic measuring devices D1 to D3 according to the functions of the respective units to obtain the optical characteristics of the light to be measured. The control processing unit 4 includes, for example, a CPU (Central Processing Unit) and its peripheral circuits. In the control processing unit 4, a control unit 41 and an optical characteristic calculation unit 42 are functionally configured by executing a control processing program. The control part 41 is for controlling each part of the optical characteristic measuring apparatus D1-D3 according to the function of each said part, respectively.

  The optical characteristic calculation unit 42 obtains predetermined optical characteristics of the light under measurement (measurement light beam L) based on the first and second spectroscopic measurement results of the first and second spectroscopic measurement units 1, 1A; It is what you want. The optical characteristic assumed in the first to third embodiments is the color of the light to be measured, and a colorimeter is assumed as the optical characteristic measuring devices D1 to D3. In the optical characteristic measurement devices D1 to D3, as described above, the first accuracy of the first spectroscopic measurement units 1 and 1A is higher than the second accuracy of the second spectroscopic measurement units 2 and 2A, and the optical characteristic calculation unit 42 Is to correct the second spectroscopic measurement result of the second spectroscopic measurement unit 2, 2 </ b> A with the first spectroscopic measurement result of the first spectroscopic measurement unit 1, 1 </ b> A to obtain the optical characteristics of the light to be measured. For this purpose, the optical characteristic calculator 42 functionally includes a characteristic calculator 421 and a correction calculator 422.

Here, the spectral distribution (first spectral measurement result) of the measured light measured by the first spectroscopic measurement unit 1 is P (λ), and the CIE color matching functions are x (λ), y (λ), z If (λ), the tristimulus value of the light to be measured is given by the following equations (1), (2), and (3). The CIE color matching functions x (λ), y (λ), and z (λ) are stored in the storage unit 9 in advance.
X = ∫P (λ) · x (λ) dλ (1)
Y = ∫P (λ) · y (λ) dλ (2)
Z = ∫P (λ) · z (λ) dλ (3)

On the other hand, each pixel value (second spectral measurement result) of each pixel (n, m) of the light to be measured measured by the second spectroscopic measurement unit 2 is expressed as Xc (n, m), Yc (n, m), Xc ( n, m), and the pixel on the second spectroscopic measurement unit 2 corresponding to the point of the light to be measured (measurement point of spot measurement) measured by the first spectroscopic measurement unit 1 is (n0, m0), Equations (4) to (6) are established. Note that (n0, m0) is examined in advance and stored in the storage unit 9.
X = f {Xc (n0, m0), Yc (n0, m0), Zc (n0, m0)} (4)
Y = g {Xc (n0, m0), Yc (n0, m0), Zc (n0, m0)} (5)
Z = h {Xc (n0, m0), Yc (n0, m0), Zc (n0, m0)} (6)

The coefficients of the functions f, g, and h in these expressions (4) to (6) are correction coefficients. When the relational expressions of these expressions (4) to (6) are set as the following expression (7), Correction coefficients α, β, and γ are obtained as in equations (8) to (10).
α = X / Xc (n0, m0) (8)
β = Y / Yc (n0, m0) (9)
γ = Z / Zc (n0, m0) (10)

…（７）

... (7)

The corrected tristimulus values of each pixel of the second spectroscopic measurement unit 2 are given by the following equations (11) to (13).
X (n, m) = α · Xc (n, m) (11)
Y (n, m) = β · Xc (n, m) (12)
Z (n, m) = γ · Xc (n, m) (13)

  Therefore, the correction calculation unit 422 calculates the correction coefficients α, β, γ as described above based on the first and second spectroscopic measurement results of the first and second spectroscopic measurement units 1, 1A; The correction coefficients α, β, γ are obtained and stored in the storage unit 9. Then, the characteristic calculation unit 421 performs correction based on the second spectroscopic measurement result of the second spectroscopic measurement unit 2 and the first and second spectroscopic measurement results of the first and second spectroscopic measurement units 1 and 1A; Based on the coefficients α, β, and γ, the tristimulus values of the light to be measured are obtained as predetermined optical characteristics by using the above-described equations (11) to (13). As described above, in the optical property measurement apparatuses D1 to D3, even if the second accuracy of the second spectroscopic measurement units 2 and 2A is relatively low, the second spectroscopic measurement results of the second spectroscopic measurement units 2 and 2A are relatively compared. Since the first spectroscopic measurement unit D1 to D3 corrects the first spectroscopic measurement result of the first spectroscopic measurement unit 1 or 1A having the first accuracy with high accuracy, The second accuracy can be improved.

  Then, the optical characteristic calculator 42 outputs the predetermined optical characteristic obtained as described above to the output unit 82. Further, as necessary, the optical characteristic calculation unit 42 outputs the predetermined optical characteristic obtained as described above to an external device (not shown) via the IF unit 83.

  In the optical characteristic measuring devices D1 to D3 as described above, when measurement is started, the light to be measured enters the light receiving lens system 6a and exits from the aperture stop 6b. In the optical characteristic measuring apparatus D1, the light to be measured that has passed through the aperture stop 6b as the measurement light beam L includes a part of the light in the light flux center region centered on the optical axis AX and the light in the light flux peripheral region positioned around the light beam. Is reflected by the branch mirror 5, its optical path is bent and guided to the first spectroscopic measurement unit 1, and the remaining part is guided as it is to the second spectroscopic measurement unit 2 through the measurement angle variable optical system 3. Is done. In the optical characteristic measuring apparatus D2, the light to be measured that has passed through the aperture stop 6b as the measurement light beam L includes a part of the light in the light beam central region centered on the optical axis AX and the light in the light beam peripheral region positioned around the light beam. Is reflected by the branch mirror 5, the optical path thereof is bent, and is guided in the order of the variable measuring angle optical system 3 and the second spectroscopic measuring unit 2, and the remaining part is guided to the first spectroscopic measuring unit 1 as it is. The In the optical characteristic measuring apparatus D3, the light to be measured that has passed through the aperture stop 6b as the measurement light beam L includes a part of the light in the light flux center region centered on the optical axis AX and the light in the light flux peripheral region positioned around the light beam. Is reflected by the branch mirror 5, the optical path thereof is bent and guided to the second spectroscopic measurement unit 2A, and the remaining part is guided as it is to the first spectroscopic measurement unit 1A.

  A part of the light to be measured (reflected light beam L1 or transmitted light beam L0) guided to the first spectroscopic measurement unit 1 or 1A is spectrally measured, and the first spectroscopic measurement result is the first spectroscopic measurement unit 1 or 1A. 1A is output to the control processing unit 4. Here, since the branch mirror 5 has small polarization dependency and angle dependency, the first spectroscopic measurement unit 1 can perform measurement more accurately even when the object to be measured has polarization characteristics or directivity. The remaining light to be measured (reflected light beam L1 or transmitted light beam L0) guided to the second spectroscopic measurement unit 2 is spectroscopically measured, and the second spectroscopic measurement result is controlled by the second spectroscopic measurement units 2 and 2A. It is output to the processing unit 4. The optical characteristic calculation unit 42 of the control processing unit 4 obtains the correction coefficients α, β, γ based on the first and second spectroscopic measurement results by the correction calculation unit 422, and the obtained correction coefficients α, β, γ Based on the two spectroscopic measurement results, the characteristic calculation unit 421 obtains a two-dimensional distribution of optical characteristics in the light to be measured and outputs the two-dimensional distribution to the output unit 82.

  As described above, the optical characteristic measuring devices D1 to D3 and the optical characteristic measuring method using the same have the line sensor 14 and the like, and the first light spectrum is obtained by measuring the measurement light beam L with the first accuracy. It has a measurement unit 1, 1 </ b> A, a second spectral measurement unit 2, 2 </ b> A that has a two-dimensional sensor 22, etc., and that measures and measures the measurement light beam L with a second accuracy. It is higher than 2 precision. Then, the optical characteristic calculation unit 42 corrects the second spectroscopic measurement result of the second spectroscopic measurement unit 2 and 2A with the first spectroscopic measurement result of the first spectroscopic measurement unit 1 and 1A, and obtains the optical characteristic of the light to be measured. It is done. The mirrors for guiding the light to be measured to the first and second spectroscopic measuring units 1, 1A; 2, 2A are not half mirrors, but the light and the light in the central region Aa of the total light flux L of the light to be measured. A part of the light beam L1 including both of the light in the peripheral region Ab is bent and guided to the first spectroscopic measurement units 1 and 1A, and the remaining light beam L0 is directly guided to the second spectroscopic measurement units 2 and 2A. A branch mirror 5 is provided. That is, the branch mirror 5 reflects and bends the light beam L1 having a part of the cross-sectional area of the measurement light beam L of the light to be measured and guides it to the first spectroscopic measurement units 1 and 1A, and the light beam of the remaining cross-sectional area. This is a mirror that guides L0 directly to the second spectroscopic measurement units 2 and 2A. Therefore, since the branch mirror 5 has small polarization dependency and angle dependency, it is possible to measure with higher accuracy even when the object to be measured has polarization characteristics or directivity.

  As in the optical characteristic measuring devices D1 to D3, the imaging optical system 6 including the light receiving lens system 6a and the aperture stop 6b is arranged on the measured object side of the branch mirror 5 in order from the measured object side to the image side. Accordingly, it is preferable that the aperture stop 6b is disposed closer to the branch mirror 5 side. By disposing the aperture stop 6b in this way, the amount of received light can be made unchanged even when the light receiving lens system 6a is focused.

  When the imaging optical system 6 is not provided with the aperture stop 6b in the optical characteristic measuring devices D1 to D3, the amount of received light changes due to the focusing of the light receiving lens system 6a, so that the control processing unit 4 includes the light receiving lens system 6a. It is preferable to functionally include a light amount correction unit that corrects the amount of received light according to focusing. In this case, the relationship between the focus position of the light receiving lens system 6a (the position of the optical lens (or lens group) moving along the optical axis AX for focusing in the light receiving lens system 6a) and the light amount correction coefficient is obtained in advance. And stored in the storage unit 9. It is preferable that the light amount correction unit is configured to correct the received light amount with a light amount correction coefficient corresponding to the focus position of the light receiving lens system 6a.

  In the optical characteristic measuring apparatuses D1 and D2 described above, a spectrophotometer using a spectroscopic optical element such as a diffraction grating is adopted as the first spectroscopic measurement unit 1, but from the optical filter 211 of the second spectroscopic measurement unit 2. Alternatively, a tristimulus photometer may be employed by using an optical filter having a highly accurate spectral response. In addition, since the above-described optical characteristic measuring devices D1 to D3 are colorimeters, in order to measure light to be measured with three types of spectral sensitivities, three optical filters 211 (RGB) having different spectral responsiveness from each other, Although F1 to F3 are used for the second spectroscopic measurement units 2 and 2A, when the optical property measurement devices D1 to D3 are luminance meters, the second spectroscopic measurement units 2 and 2A are covered with one type of spectral sensitivity. A configuration for measuring the measurement light may be used.

D1 to D3 Optical characteristic measuring device IM1, IM2 First and second images SP Measurement area (object to be measured)
AX Optical axis AX0 Transmitted optical axis AX1 Reflected optical axis A0 Transmitted area A1 Reflected area Aa Light flux center area Ab Light flux peripheral area L Measurement light flux L0 Transmitted light flux L1 Reflected light flux FB Bundle fiber F1 to F3 First to third optical filters S1 to S3 1st-3rd sensor 1, 1A 1st spectroscopic measurement part 2, 2A 2nd spectroscopic measurement part 3 Measurement angle variable optical system 4 Control processing part 5, 5a-5e Branch mirror 6 Imaging optical system 6a Light receiving lens system 6b Aperture Aperture 8 Input / output unit 9 Storage unit 10 Case 11 Entrance aperture 12 Lens system 13 Reflective diffraction grating 14 Line sensor (first and second sensors; colorimetric sensor)
21 Filter selection unit 22 Two-dimensional sensor (first and second sensors; two-dimensional color image sensor)
DESCRIPTION OF SYMBOLS 41 Control part 42 Optical characteristic calculating part 81 Input part 82 Output part 83 IF part 211 Optical filter 212 Filter holding member 213 Motor 421 Characteristic calculating part 422 Correction calculating part

Claims (9)

An imaging optical system that emits a measurement light beam for forming an image of the object to be measured;
A branch mirror that divides the measurement light beam into a transmitted light beam and a reflected light beam, and divides the optical axis of the imaging optical system into a transmitted light axis on the transmitted light beam side and a reflected optical axis on the reflected light beam side;
A first sensor disposed on the transmitted optical axis;
A second sensor disposed on the reflected optical axis;
An optical characteristic measuring device comprising:
One of the first and second sensors is a colorimetric sensor, and the other is a two-dimensional color image sensor,
The branch mirror has a transmission region that transmits the measurement light beam and a reflection region that reflects the measurement light beam;
Both the transmission region and the reflection region are formed so as to receive both the light in the central region of the light beam centered on the optical axis and the light in the peripheral region of the light beam positioned around the light beam in the measurement light beam. An optical characteristic measuring apparatus.   2. The optical characteristic measuring apparatus according to claim 1, wherein a boundary between the light flux central region and the light flux peripheral region is located at a half of a distance from an optical axis to an outermost edge in the measurement light flux.   The optical characteristic measuring apparatus according to claim 1, wherein the transmission area and the reflection area are alternately positioned with a radial line centered on the optical axis as a boundary.   The optical characteristic measuring device according to claim 1, wherein the transmission region and the reflection region are alternately arranged in a stripe pattern in a lattice-like stripe pattern.   The optical characteristic measuring apparatus according to claim 1, wherein the transmission area and the reflection area are arranged in a mosaic pattern in a square checkered pattern and are alternately arranged.   6. The optical characteristic measuring apparatus according to claim 1, wherein an area ratio between the transmission region and the reflection region is 1: 9 to 5: 5.   The optical characteristic measurement apparatus according to claim 1, wherein the branch mirror is provided with the reflection region by forming a reflection film on a transparent flat plate surface.   The optical characteristic measurement apparatus according to claim 1, wherein the branch mirror is provided with the reflection region by arranging a micro mirror on a virtual plane. A first spectroscopic measurement unit that has the colorimetric sensor and that measures and measures the measurement light beam with a first accuracy; and the two-dimensional color imaging device; and the measurement light beam has a second accuracy. A second spectroscopic measurement unit that performs spectroscopic measurement.
The optical characteristic measuring apparatus according to claim 1, wherein the first accuracy is higher than the second accuracy.

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