JP2016099176A - Color inspection method and color inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color inspection method and color inspection device that can perform a highly accurate inspection of a color with ease and in short time.SOLUTION: A color inspection method is configured to: acquire measurement values of colors of at least three reference light having a color in the vicinity of inspection object light and mutually different in a color by each of first color measurement means acquiring a measurement value of a color of light incident from outputs of three optical detection units in accordance with light incidence upon the three optical detection units mutually different in a wavelength characteristic of optical detection sensitivity, and second color measurement means acquiring a measurement value of a color of incident light with higher accuracy than the first color measurement means in the same colorimetric system as the measurement value by the first color measurement means; calculate a coefficient of a conversion formula converting the three measurement values of the colors of the at least reference light obtained by the first color measurement means to the measurement values by the second measurement means or approximate values, respectively. Further, The measurement value of the color of the inspection object light by the first color measurement means is converted to correct the measurement value.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a color inspection method and a color inspection apparatus.

Conventionally, as a device for measuring the color of light emitted from a lighting device or the like, a spectral color measurement device and a stimulus value direct-reading color measurement device are known.
The spectroscopic color measuring device can measure a color with high accuracy based on a spectrum obtained by splitting incident light and three color matching functions defined by CIE (International Commission on Illumination). However, the spectroscopic color measuring device requires a long time for measurement and has a limited area for measurement.
On the other hand, the stimulus value direct-reading type color measuring apparatus can perform measurement in a short time and in a large area as compared with the spectral type color measuring apparatus. However, since it is difficult to match the spectral sensitivity characteristics of each photodetector for obtaining a stimulus value with a color matching function, generally, a stimulus value direct-reading type color measuring device is compared with a spectral type color measuring device. Color measurement accuracy is poor.

For inspection applications such as lighting devices, high-precision light color measurement is required in a short time. Therefore, as a method for improving the light color measurement accuracy by the stimulus value direct-reading type color measuring device capable of measuring in a short time, the conversion coefficient obtained in advance for the measured value by the stimulus value direct-reading type color measuring device A technique for performing calibration by multiplying by is known.
For example, in Patent Document 1, a conversion coefficient is obtained for each of a plurality of light fluxes having different wavelengths from a deviation between a measured value obtained by a standard measuring instrument that is a spectral color measuring device and a measured value obtained by a stimulus value direct-reading colorimeter. A method for calibrating a measurement value with a colorimeter using a conversion coefficient selected according to the wavelength of light to be measured is disclosed.
Further, in Patent Document 2, light having three wavelengths corresponding to the vertex of a triangle having the smallest chromaticity and including the chromaticity of a measured value among triangles having apexes at three points indicating a single wavelength on the xy chromaticity diagram. A method is disclosed in which a conversion coefficient is calculated using, and a measurement value obtained by a stimulus value direct-reading type color measuring apparatus is multiplied by the conversion coefficient for calibration.

JP 2001-324386 A JP 2008-304362 A

However, the conventional method has a problem that the color difference between the color of the light used for deriving the conversion coefficient and the color of the light to be inspected becomes large, and calibration with high accuracy cannot be performed.
Thus, in the conventional method, there is a problem that it is difficult to perform an inspection with high measurement accuracy in a short time.

  An object of the present invention is to provide a color inspection method and a color inspection apparatus capable of easily and accurately performing color inspection in a short time.

In order to achieve the above object, the invention of the color inspection method according to claim 1 comprises:
A color inspection method for inspecting colors,
First color measurement means for obtaining a measurement value of the color of the incident light from the outputs of the three light detection units according to the incidence of light on three light detection units having different wavelength characteristics of light detection sensitivity; And each of the second color measuring means that obtains the measured value of the color of the light with higher accuracy than the first color measuring means in the same color system as the measured value by the first color measuring means. A reference light measurement step for obtaining measured values of at least three reference light colors having colors in the vicinity of the light and having different colors from each other;
In the reference light measuring step, the measured values of the colors of the at least three reference lights obtained by the first color measuring means are converted into measured values by the second color measuring means or approximate values of the measured values, respectively. A coefficient calculation step for calculating the coefficient of the conversion formula;
An inspection object light measurement step of obtaining a measurement value of the color of the inspection object light by the first color measurement means;
A correction step of correcting the measurement value by converting the measurement value of the color in the inspection object light measurement step by the conversion formula,
It is characterized by including.

The invention described in claim 2 is the color inspection method according to claim 1,
Each of the at least three reference lights is a light whose color measurement value acquired by the second color measuring means is an outer edge or an inner color of an inspection standard indicating a color range related to the inspection of the inspection target light. It is characterized by being.

The invention described in claim 3 is the color inspection method according to claim 1 or 2,
Any one of the at least three reference lights includes a color measured by the second color measuring unit and a center color of an inspection standard indicating a color range related to the inspection of the inspection target light. It is the light that becomes.

The invention according to claim 4 is the color inspection method according to any one of claims 1 to 3,
At least one of the at least three reference lights is a color of an outer edge of an inspection standard in which a measurement value of a color acquired by the second color measurement unit indicates a color range related to the inspection of the inspection target light. It is the light which becomes any of these.

The invention according to claim 5 is the color inspection method according to any one of claims 2 to 4,
The color range indicated by the inspection standard is a color range indicated by the MacAdam ellipse Step3, and the center color of the inspection standard is the color of the center of the MacAdam ellipse Step3.

The invention described in claim 6 is the color inspection method according to any one of claims 1 to 5,
Each of the at least three reference lights is light emitted in different directions from one organic light emitting means having an organic light emitting layer.

The invention according to claim 7 is the color inspection method according to any one of claims 1 to 6,
In the reference light measurement step, at least four colors of the reference light are measured,
In the coefficient calculating step, the measured values by the first color measuring means of the colors of the at least four reference lights in the reference light measuring step are converted into approximate values of the measured values by the second color measuring means, respectively. It is characterized by calculating the coefficient of the conversion formula by the least square method.

The invention according to claim 8 is the color inspection method according to any one of claims 1 to 7,
The second color measurement means is characterized in that a measurement value of the color of the incident light is obtained from an integral value of a product of a spectrum obtained by separating the incident light and a color matching function.

In order to achieve the above object, the invention of the color inspection apparatus according to claim 9
A color inspection device for inspecting colors,
First color measuring means for obtaining a measured value of the color of the incident light from the outputs of the three light detecting sections according to the incidence of light on three light detecting sections having different wavelength characteristics of light detection sensitivity; ,
The second color that obtains the measurement value of the color of the light with higher accuracy than the first color measurement unit in the same color system as the measurement value by the first color measurement unit and the first color measurement unit. A coefficient of a conversion formula calculated based on measured values of colors of at least three reference lights each having a color in the vicinity of the inspection target light and different from each other by each of the measurement means, the first color measurement Storage means for storing coefficients of conversion equations for converting the measured values of the colors of the at least three reference lights obtained by the means into measured values by the second color measuring means or approximate values of the measured values, respectively;
Correction means for converting the measurement value of the color of the inspection object light by the first color measurement means by the conversion formula and correcting the measurement value;
It is characterized by having.

  According to the present invention, there is an effect that highly accurate color inspection can be performed easily and in a short time.

It is a figure which shows schematic structure of a color inspection system. It is a block diagram which shows the main function structures of a stimulus value direct-reading type color measuring apparatus and information processing apparatus. It is a block diagram which shows the main function structures of a spectral type color measuring apparatus. It is a figure which shows schematic structure of a light source. It is a figure which shows the example of the test | inspection standard of a color test | inspection system. It is a flowchart which shows the control procedure of a conversion type | formula acquisition process. It is a flowchart which shows the control procedure of a color inspection process.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to a color inspection method and a color inspection apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a color inspection system 1 of the present embodiment.
The color inspection system 1 includes a stimulus value direct-reading color measuring device 10 (color inspection device, first color measuring means), a spectral color measuring device 20 (second color measuring means), and a stimulus value direct-reading color measurement. An information processing apparatus 30 connected to the apparatus 10 and the spectral color measuring apparatus 20 and a light source 40 (organic light emitting means) for irradiating light to the stimulus value direct reading color measuring apparatus 10 and the spectral color measuring apparatus 20 are provided. The stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20 according to the present embodiment acquire tristimulus values of the XYZ color system as color measurement values.

FIG. 2 is a block diagram illustrating main functional configurations of the stimulus value direct-reading color measuring apparatus 10 and the information processing apparatus 30.
The stimulus value direct-reading type color measuring apparatus 10 includes light detection units 13R, 13G, and 13B including color filters 11R, 11G, and 11B and light reception units 12R, 12G, and 12B (hereinafter simply referred to as color filter 11, light reception unit 12, and light detection). Section 13), ADCs 14R, 14G, and 14B (Analog-Digital Converter) (hereinafter also simply referred to as ADC 14), a CPU 15 (Central Processing Unit) (correction means), and a RAM 16 (Random Access). Memory (storage means), ROM 17 (Read Only Memory), interface 18, bus 19, and the like. The CPU 15 is connected to the ADC 14, RAM 16, ROM 17, and interface 18 via the bus 19.

The color filters 11R, 11G, and 11B have different transmittance wavelength characteristics, and are elements that transmit red, green, and blue light from incident light from the light source 40, respectively. The light transmitted through the color filters 11R, 11G, and 11B is incident on the light receiving units 12R, 12G, and 12B, respectively.
An optical system such as a condensing lens that condenses incident light from the light source 40 may be provided between the color filter 11 and the light source 40.

The light receiving unit 12 receives light incident from the color filter 11 and outputs a voltage corresponding to the intensity of the received light to the ADC 14. The light receiving unit 12 includes, for example, a photodiode as a photoelectric conversion element, a conversion circuit that converts an output current of the photodiode into a voltage, and an amplifier that amplifies the output of the conversion circuit.
The light receiving sensitivity indicating the magnitude of the output voltage of the light receiving unit 12 with respect to the intensity of light incident on the light receiving unit 12 has a predetermined wavelength characteristic. Moreover, the structure of each light-receiving part 12 is the same, therefore the wavelength characteristics of the light-receiving sensitivity are almost the same.

The color filter 11R and the light receiving unit 12R constitute a light detecting unit 13R corresponding to red, the color filter 11G and the light receiving unit 12G constitute a light detecting unit 13G corresponding to green, and the color filter 11B and the light receiving unit 12B. A light detection unit 13B corresponding to blue is configured.
The light detection units 13R, 13G, and 13B output signals corresponding to the incident light intensity to the ADC 14R, ADC 14G, and ADC 14B, respectively, with light detection sensitivity having a predetermined wavelength characteristic (that is, with predetermined spectral sensitivity characteristic). Accordingly, the spectral sensitivity characteristics of the light detection units 13R, 13G, and 13B are represented by products of the transmittance wavelength characteristics of the color filters 11R, 11G, and 11B and the wavelength characteristics of the light reception sensitivity of the light receiving units 12R, 12G, and 12B, respectively. . Further, the characteristics of the color filter 11 and the light receiving unit 12 are adjusted so that the spectral sensitivity characteristics of the respective light detection units 13 are close to the color matching function.
Further, the output signal from the light detection unit 13 is a value obtained by integrating the product of the intensity of each wavelength component of the incident light and the light detection sensitivity at the wavelength of the light detection unit 13 (that is, the spectrum of the incident light and the light detection). Integral value of the product with the spectral sensitivity characteristic of the unit 13). This output signal represents a tristimulus value in the XYZ color system of incident light according to the spectral sensitivity characteristic of each light detection unit 13.
In the stimulus value direct-reading type color measuring apparatus 10, the spectral sensitivity characteristic of the light detection unit 13 is adjusted to be close to the color matching function as described above, but it is difficult to completely match the color matching function. For this reason, the tristimulus values acquired by the stimulus value direct-reading color measuring apparatus 10 are different from the tristimulus values calculated based on the color matching function. That is, the color measurement value by the stimulus value direct-reading type color measurement device 10 includes an error with respect to the measurement value measured based on the color matching function.

  The ADCs 14R, 14G, and 14B convert the analog signals input from the light detection units 13R, 13G, and 13B into digital signals and output the digital signals.

  The CPU 15 performs various arithmetic processes and controls the overall operation of the stimulus value direct-reading color measuring apparatus 10. The CPU 15 stores each output of the ADC 14 representing tristimulus values of incident light in the RAM 16 as color measurement values (R, G, B). Further, the CPU 15 converts correction values (Xc, Yc) obtained by converting and correcting (calibrating) the measurement values (R, G, B) of the color of the inspection target light based on the coefficient data of the conversion formula stored in the RAM 16. , Zc) is stored in the RAM 16. Further, the CPU 15 converts the color system of the correction value (Xc, Yc, Zc), acquires the inspection value (x, y), and stores it in the RAM 16. Further, the CPU 15 determines whether the inspection value (x, y) is suitable for the inspection standard, and stores the determination result in the RAM 16.

  The RAM 16 provides a working memory space to the CPU 15 and stores temporary data. Further, the RAM 16 has the inspection values (R, G, B), correction values (Xc, Yc, Zc), inspection values (x, y), inspection values (x, y) calculated by the CPU 15. The result of the determination of suitability, the coefficient data of the conversion formula, and the chromaticity range information indicating the inspection standard are stored.

  The ROM 17 stores various control programs executed by the CPU 15 and setting data. The program includes, for example, a color measurement program for measuring the color of incident light, a correction program for color measurement values, an XYZ color system correction value (Xc, Yc, Zc), and an xyY color system inspection value (x , Y), a color system conversion program, a determination program for determining suitability of the inspection value (x, y) to the inspection standard, and the like.

  The interface 18 is means for transmitting and receiving data to and from the interface 34 of the information processing apparatus 30 and is configured by various serial interfaces.

Next, the main functional configuration of the information processing apparatus 30 will be described.
The information processing apparatus 30 includes a CPU 31, a RAM 32, a storage unit 33, an interface 34, an operation input unit 35, a display unit 36, a bus 37, and the like. The CPU 31 is connected to the RAM 32, the storage unit 33, the interface 34, the operation input unit 35, and the display unit 36 via the bus 37. The information processing apparatus 30 is a personal computer, for example.

  The CPU 31 performs various arithmetic processes and controls the overall operation of the information processing apparatus 30. For example, the CPU 31 executes a program stored in the storage unit 33 in accordance with an output signal from the operation input unit 35 and causes the display unit 36 to display the result. Further, the CPU 31 causes the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20 to perform a color measurement operation by outputting a control signal from the interface 34. Further, the CPU 31 calculates the coefficient of the conversion formula from the measured value of the color of the reference light stored in the RAM 32 and stores it in the RAM 32 and the RAM 16 of the stimulus value direct-reading color measuring apparatus 10.

  The RAM 32 provides a working memory space to the CPU 31 and stores temporary data. Further, the RAM 32 temporarily stores data necessary for the calculation of the conversion equation coefficient by the CPU 31 and the calculated conversion equation coefficient data.

  The storage unit 33 is configured by a rewritable nonvolatile memory such as a flash memory or a magnetic storage device, and stores various control programs executed by the CPU 31, setting data, and the like. The program includes, for example, a program for calculating a conversion coefficient.

  The interface 34 is a means for transmitting / receiving data between the interface 18 of the stimulus value direct-reading color measuring apparatus 10 and the interface 27 (FIG. 3) of the spectral color measuring apparatus 20, and is composed of various serial interfaces.

  The operation input unit 35 includes a keyboard, a mouse, a touch panel, and the like, and receives an operation instruction input from the user and outputs a signal corresponding to the input. The operation instruction input to the operation input unit 35 includes an instruction to perform a color measurement operation on the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20.

  The display unit 36 is configured by a liquid crystal display device or the like, and displays the execution result of the program by the CPU 31.

FIG. 3 is a block diagram showing the main functional configuration of the spectral color measurement apparatus 20.
The spectroscopic color measurement apparatus 20 includes a diffraction grating 21, a light receiving unit 22, an ADC 23, a CPU 24, a RAM 25, a ROM 26, an interface 27, a bus 28, and the like. The CPU 24 is connected to the ADC 23, RAM 25, ROM 26, and interface 27 via the bus 28.

  The diffraction grating 21 diffracts incident light from the light source 40 that has been converted into parallel light by an optical system (not shown) by a grating-shaped groove, and generates interference patterns of light of each wavelength at different positions on the light incident surface of the light receiving unit 22. This is an element that splits incident light.

  The light receiving unit 22 is a line sensor including a plurality of image pickup devices arranged in a line on the light incident surface thereof, and receives light of different wavelengths separated by the diffraction grating 21 in each image pickup device. Each voltage signal corresponding to the intensity of the light is output to the ADC 23. Therefore, the output from the light receiving unit 22 represents the spectrum of incident light. As the imaging element, for example, a CMOS (Complementary Metal Oxide Semiconductor) sensor or a CCD (Charge Coupled Device) sensor provided with a photodiode as a photoelectric conversion element can be used.

  The ADC 23 converts the analog signal input from the light receiving unit 22 into a digital signal and outputs the digital signal.

The CPU 24 performs various arithmetic processes and controls the overall operation of the spectral color measurement apparatus 20. The CPU 24 calculates tristimulus values of the XYZ color system from the color matching function data stored in the RAM 25 and the output of the ADC 23 representing the spectrum of incident light, and uses the tristimulus values as color measurement values (X, Y). , Z) is stored in the RAM 25.
In this way, the spectroscopic color measurement device 20 uses the tristimulus value calculated from the spectrum of the incident light and the color matching function as the measurement value (X, Y, Z). Color can be measured with high accuracy. Here, high color measurement accuracy means that a measurement value obtained by measuring a measurement object whose color is specified in advance in a uniform color space such as an L ^* a ^* b ^* color system and the measurement object. This means that the color difference from the color of the object is small.

  The RAM 25 provides a working memory space for the CPU 24 and stores temporary data. The RAM 25 stores color matching function data. The RAM 25 stores measurement values (X, Y, Z) calculated by the CPU 24.

  The ROM 26 stores various control programs executed by the CPU 24, setting data, and the like. The program includes, for example, a color measurement program that measures the color of incident light.

  The interface 27 is a means for transmitting and receiving data to and from the interface 34 of the information processing apparatus 30 and includes various serial interfaces. The interface 34 of the information processing apparatus 30 connected to the interface 27 may be the same as or separate from the interface 34 connected to the interface 18 of the stimulus value direct-reading color measuring apparatus 10. Good.

4A and 4B are diagrams showing a schematic configuration of the light source 40. FIG. 4A is a perspective view, and FIG. 4B is a plane parallel to the XZ plane including the AA ′ line in FIG. FIG.
The light source 40 is an organic light emitting device using an organic EL (Electro Luminescence) element, and irradiates the stimulus value direct-reading color measuring device 10 or the spectral color measuring device 20 with reference light or inspection target light. The light source 40 includes a glass substrate 41 and a sealing glass 42 that form a space therein, a light-transmitting anode 43, an organic light emitting layer 44, and a glass substrate 41 that are sequentially laminated on the surface of the glass substrate 41 on the sealing glass 42 side. A cathode 45 is provided. The glass substrate 41 and the sealing glass 42 are adhered and sealed with a photo-curing adhesive 46 in a state where the internal space is filled with nitrogen gas.
The organic light emitting layer 44 is composed of, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. A voltage is applied between the anode 43 and the cathode 45 and a drive current flows. It emits light. The organic light emitting layer 44 may be configured to include a single light emitting layer that emits white light, or may have a configuration in which each light emitting layer that emits red, green, and blue light is stacked. Good.
Part of the light from the organic light emitting layer 44 is directly emitted from the glass substrate 41 side, and part of the light is reflected by the cathode 45 and emitted from the glass substrate 41 side. Other part of the light is reflected a plurality of times in the resonance structure formed between the surface of the anode 43 and the glass substrate 41 (or the interface when the organic light emitting layer 44 is a multilayer) and the cathode 45. After that, it is injected from the glass substrate 41 side.

  In the light source 40, the color of the emitted light has an angle dependency due to the fact that the interference condition in the resonant structure varies depending on the light emission angle. That is, the light source 40 has a characteristic that the color of the emitted light changes according to the emission angle θ shown in FIG.

As shown in FIG. 1, the light source 40 of the color inspection system 1 of the present embodiment is movable relative to the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20, and the stimulus value. The direct reading color measurement device 10 and the spectral color measurement device 20 are each irradiated with light under the same conditions. The light source 40 is configured to be rotatable around a predetermined rotation axis, and irradiates light emitted at various emission angles θ to the stimulus value direct-reading color measuring device 10 and the spectral color measuring device 20. .
In the color inspection system 1, the light source 40 that emits the reference light used for calculating the coefficient of the conversion equation and the plurality of light sources 40 that emit the inspection target light that is the inspection target by the color inspection system 1 are appropriately replaced. Used. The light source 40 that emits inspection target light is, for example, an illuminating device, and the light source 40 that emits reference light is, for example, an illuminating device that can irradiate light in or near the inspection standard of the illuminating device.

Next, a color inspection method by the color inspection system 1 will be described.
In the color inspection system 1, the color of the inspection target light is measured by the stimulus value direct reading type color measuring device 10. However, as described above, the color measurement values (R, G, B) obtained by the stimulus value direct-reading color measurement device 10 include an error with respect to the measurement values (X, Y, Z) obtained by the spectral color measurement device 20. It is out. Therefore, the color inspection system 1 converts and corrects the measured values (R, G, B) of the color of the light to be inspected by the stimulus value direct-reading color measurement device 10 using the coefficients of the conversion formula prepared in advance, thereby correcting the correction value ( Xc, Yc, Zc) is acquired. Then, the inspection value (x, y) is obtained by converting the color system of the correction value (Xc, Yc, Zc), and the obtained inspection value (x, y) conforms to a predetermined inspection standard. It is determined whether or not there is.

FIG. 5 is a diagram illustrating an example of the inspection standard of the color inspection system 1.
In the color inspection system 1 of the present embodiment, the inspection standard is a range indicated by the MacAdam ellipse Step 3 in the xy chromaticity diagram in the xyY color system. In addition to this, MacAdam ellipses Step1, Step2, and Step4 are also drawn in FIG.

  The MacAdam ellipse Step 1 performs a number of color matching experiments on a specific color (center color) on the xy chromaticity diagram, and plots the standard deviation of the resulting distribution for each of a plurality of directions from the center color. It was obtained. The MacAdam ellipse Step 1 represents a chromaticity range in which the human eye cannot distinguish the color difference from the center color. Further, the MacAdam ellipse Step 3 is an ellipse in which the lengths of the major axis and the minor axis are each three times that of the MacAdam ellipse Step 1. The MacAdam ellipse Step 3 includes chromaticity that allows the human eye to determine the color difference from the center color. However, in a lighting device that emits light from a light emitting unit, etc. It is supposed that it represents a chromaticity range that is allowed by the public. For this reason, the MacAdam ellipse Step 3 is one of the typical standards relating to the color of products such as lighting devices.

  A MacAdam ellipse can be derived for any point (x, y) on the xy chromaticity diagram. That is, the inspection standard of the MacAdam ellipse Step 3 can be determined by three parameters that define the MacAdam ellipse for an arbitrary chromaticity, that is, the length of the major axis, the length of the minor axis, and the inclination of the major axis with respect to the x axis. For example, a MacAdam ellipse Step 3 centered on a point (0.450, 0.400) has a major axis length of 0.016, a minor axis length of 0.008, and a major axis inclination of 51 with respect to the x-axis. .4 degrees, point P1 (0.455, 0.406), point P2 (0.447, 0.403), point P3 (0.445, 0.394), point P4 (0.453, 0) .397) etc.

Next, a conversion formula used for correcting the measurement values (R, G, B) of the stimulus value direct-reading color measurement apparatus 10 in the color inspection system 1 and a conversion matrix having components of the conversion formula as components will be described.
In the color inspection method by the color inspection system 1, three reference light colors that have colors in the vicinity of the inspection target light and have different colors are measured by the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20. Of these, the coefficient of the conversion formula for converting the measured value by the stimulus value direct-reading color measuring device 10 into the measured value by the spectral color measuring device 20 is calculated. Here, the color range in the vicinity of the inspection target light is, for example, a range represented on the inside or on the outer edge of the MacAdam ellipse Step 3 which is an inspection standard. Further, the color range in the vicinity of the inspection target light is a color range in the vicinity of the inspection standard, that is, the major axis and the minor axis are a predetermined number of times (1.2 times, 1.5 times, etc.) of the MacAdam ellipse Step3. It may include a range represented on the inner or outer edge of a certain ellipse.

Specifically, measured values (R (i), G (i), B (i)) of the i-th (i is an integer satisfying 1 ≦ i ≦ 3) reference light stimulus value direct-reading color measuring apparatus 10 And a conversion matrix satisfying the following expression is calculated for the measurement values (X (i), Y (i), Z (i)) by the spectral color measurement device 20. Each component _X r of the transformation _{matrix, X g, X b, Y} r, Y g, Y b, Z r, Z g, Z b correspond to the coefficients of the conversion formula.

From the above equation, the following ternary linear equations for X _r , X _g , and X _b are derived. _Xr , _Xg , and _Xb can be obtained from this ternary simultaneous linear equation.
X (1) = X _r · R (1) + X _g · G (1) + X _b · B (1)
_{X (2) = X r ·} R (2) + X g · G (2) + X b · B (2)
_{X (3) = X r ·} R (3) + X g · G (3) + X b · B (3)
Y _r , Y _g , and Y _b can be obtained from the following ternary simultaneous linear equations derived from the above equations.
Y (1) = _Yr · R (1) + Y _g · G (1) + Y _b · B (1)
Y (2) = _Yr · R (2) + Y _g · G (2) + Y _b · B (2)
Y (3) = _Yr · R (3) + Y _g · G (3) + Y _b · B (3)
Z _r , Z _g , and Z _b can be obtained by the following ternary simultaneous linear equation derived from the above equation.
_{Z (1) = Z r ·} R (1) + Z g · G (1) + Z b · B (1)
_{Z (2) = Z r ·} R (2) + Z g · G (2) + Z b · B (2)
_{Z (3) = Z r ·} R (3) + Z g · G (3) + Z b · B (3)

The three reference lights used for calculating the coefficients of the conversion formula are selected from light whose color measured by the spectroscopic color measuring device 20 is in or near the MacAdam ellipse Step3. For example, the reference light can be light corresponding to three different colors on the MacAdam ellipse Step3. Further, any one of the reference lights may be light corresponding to the color of the center of the MacAdam ellipse Step3. Alternatively, some or all of the reference light may be light corresponding to a color other than the central color inside the MacAdam ellipse Step 3.
The reference light of each color can be obtained by changing the light emission angle θ from the light source 40.

  Next, conversion formula acquisition processing in the color inspection system 1 will be described.

FIG. 6 is a flowchart showing the control procedure of the conversion formula acquisition process.
The CPU 31 of the information processing device 30 outputs a control signal to the CPU 15 of the stimulus value direct-reading color measurement device 10 in a state where the reference light is irradiated from the light source 40 to the stimulus value direct-reading color measurement device 10, and the stimulus value direct-reading type. The color measurement device 10 is caused to measure the color of the reference light (step S11: reference light measurement step).
In step S <b> 11, when a control signal instructing execution of a color measurement operation is input from the information processing apparatus 30 via the interface 18, the CPU 15 reads and executes a color measurement program from the ROM 17. The CPU 15 outputs a control signal to the light detection unit 13 to output a signal representing the tristimulus values reflecting the spectrum of the reference light and the spectral sensitivity characteristics of each light detection unit 13, and outputs a control signal to the ADC 14. Then, the measured values (R (i), G (i), B (i)) of the colors corresponding to the stimulus values are acquired from the ADC 14 and stored in the RAM 16.
The color measurement operation by the stimulus value direct-reading color measurement device 10 is started when a measurement operation start instruction is directly input by a user from an input unit (not shown) provided in the stimulus value direct-reading color measurement device 10. Also good.
When step S11 ends, the light source 40 is moved relative to the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20, and the same reference light as the reference light in step S11 is emitted from the light source 40 to the spectral color. The measurement device 20 is irradiated.

The CPU 31 outputs a control signal to the CPU 24 of the spectral color measurement device 20 in a state where the spectral color measurement device 20 is irradiated with the reference light from the light source 40, and the spectral color measurement device 20 has the same color as step S11. The reference light is measured (step S12: reference light measurement step).
In step S <b> 12, when a control signal instructing execution of a color measurement operation is input from the information processing apparatus 30 via the interface 27, the CPU 24 reads out and executes the color measurement program from the ROM 26. The CPU 24 outputs a control signal to the light receiving unit 22 and the ADC 23, and causes the ADC 23 to output a signal corresponding to the intensity of different wavelength components of the reference light incident on each photoelectric conversion element of the light receiving unit 22. The CPU 24 multiplies the spectrum of the reference light represented by the output by the three color matching function data stored in the RAM 25 and integrates them to calculate tristimulus values in the XYZ color system. The CPU 24 stores the tristimulus values in the RAM 25 as measured values (X (i), Y (i), Z (i)).
Note that the color measurement operation by the spectral color measurement device 20 may be started by directly inputting a measurement operation start instruction by a user from an input unit (not shown) provided in the spectral color measurement device 20.

  The CPU 31 determines whether or not the color measurement by the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20 has been completed for all (three) reference lights used for calculating the coefficients of the conversion equation (step) S13). When it is determined that the measurement of the reference light of any color is not completed (“NO” in step S13), the stimulus value direct-reading color measuring device 10 from the light source 40 is changed by changing the angle of the light source 40. Then, the emission angle θ of the light emitted to the spectroscopic color measurement device 20 is changed, and light of a color for which measurement has not been completed is emitted from the light source 40 (step S14). The process of step S14 may be performed by operating a motor attached to the light source 40 under the control of the CPU 31, or may be performed by a human hand. When step S14 is completed, the CPU 31 shifts the process to step S11.

If it is determined in step S13 that the measurement of all the reference light colors has been completed (“YES” in step S13), the CPU 31 determines the stimulus value direct-reading color measurement device 10 for the three measured reference lights. The conversion formula based on the measured values (R (i), G (i), B (i)) by the color and the measured values (X (i), Y (i), Z (i)) by the spectral color measuring device 20 Is calculated (step S15: coefficient calculation step). Specifically, the CPU 31 reads out the measured values (R (i), G (i), B (i)) of the three reference lights from the RAM 16 of the stimulus value direct-reading color measuring apparatus 10 and stores them in the RAM 32. Then, the measured values (X (i), Y (i), Z (i)) of the three reference light colors are read from the RAM 25 of the spectral color measuring apparatus 20 and stored in the RAM 32. The coefficient _X r conversion equation according to the calculation method described _{above, X g, X b, Y} r, Y g, Y b, Z r, Z g, calculates a _{Z b.} The CPU 31 stores the calculated conversion formula coefficient data in the RAM 16 of the stimulus value direct-reading color measuring apparatus 10 and then ends the conversion formula acquisition process.
Note that the measured values (R (i), G (i), B (i)) and measured values (X (i), Y (i), Z) of the three reference lights used for calculating the coefficients of the conversion equation (I)) may be directly stored in the RAM 32 of the information processing apparatus 30 when acquired in steps S11 and S12, respectively.

  Next, color inspection processing in the color inspection system 1 will be described.

FIG. 7 is a flowchart showing the control procedure of the color inspection process.
The CPU 31 outputs a control signal to the CPU 15 of the stimulus value direct-reading color measurement device 10 in a state where the light to be inspected is irradiated from the light source 40 to the stimulus value direct-reading color measurement device 10, and the stimulus value direct-reading color measurement device 10. To measure the color of the inspection target light (step S21: inspection target light measurement step). The CPU 15 stores the measured values (R, G, B) of the color of the inspection target light in the RAM 16.
Note that the measurement operation of the color of the inspection target light by the stimulus value direct-reading color measuring apparatus 10 is that the user directly inputs a measurement operation start instruction from an input unit (not shown) provided in the stimulus value direct-reading color measuring apparatus 10. May be started.

  The CPU 15 converts and corrects the measurement value of the color of the inspection target light acquired in step S21 using the coefficient data of the conversion formula calculated in step S15, and corrects the correction value (Xc, Yc, Zc). Obtain (step S22: correction step). Specifically, the CPU 15 obtains a correction value (Xc, Yc, Zc) from the measured value (R, G, B) of the inspection target light stored in the RAM 16 and the coefficient data of the conversion formula by processing based on the following conversion formula. Calculate and acquire. The CPU 15 stores the acquired correction value (Xc, Yc, Zc) in the RAM 16.

  The CPU 15 calculates the inspection value (x, y) from the correction value (Xc, Yc, Zc) acquired in step S22, and determines whether the inspection value (x, y) is appropriate for the inspection standard (step S23). ). Specifically, the CPU 15 converts the correction value (Xc, Yc, Zc) into the xyY color system by the following formula, and the obtained inspection value (x, y) is the color of the inspection standard stored in the RAM 16. It is determined whether it is included in or within the range, that is, the MacAdam ellipse Step 3. The CPU 15 stores data indicating the determination result and data for identifying the determined inspection target light in the RAM 16.

When step S23 is completed, it is determined whether or not all the inspection target light has been inspected (step S24). Step S24 may be performed by a user who performs an inspection, or a list of inspection target lights is stored in advance in the RAM 16 of the stimulus value direct-reading color measurement apparatus 10, and all inspection target lights listed by the CPU 15 are stored. It may be determined whether or not the inspection is completed. If it is determined that the inspection of any of the inspection target lights has not been completed (“NO” in step S24), the light source 40 is replaced and the stimulation value direct-reading color measuring apparatus 10 has not been inspected. The process returns to step S21 in a state where the inspection target light is irradiated.
If it is determined that all the inspection target lights have been inspected (“YES” in step S24), the CPU 15 ends the color inspection process.

  As described above, in the color inspection method according to the present embodiment, the light is incident from the outputs of the three light detection units 13 according to the incidence of light to the three light detection units 13 having different wavelength characteristics of the light detection sensitivity. Stimulus value direct-reading color measurement device 10 that obtains a measurement value of the color of light, and the same color system as the measurement value by the stimulus value direct-reading color measurement device 10 is more accurate than the stimulus value direct-reading color measurement device 10 A reference light measurement step of obtaining measured values of three reference lights having different colors from each other by each of the spectral color measuring devices 20 for obtaining the measured values of the light colors. In the reference light measurement step, coefficient calculation is performed for calculating coefficients of conversion equations for converting the measured values of the three reference light colors obtained by the stimulus value direct-reading color measuring device 10 into the measured values by the spectral color measuring device 20, respectively. Step, stimulus value direct reading type color measurement Test target light measuring step of measuring the color of the test target light by location 10, including the correction step, to correct the measured value is converted by the conversion equation measured value of the color in the test target light measuring step. Thereby, it is possible to realize easy and short-time color measurement by the stimulus value direct-reading color measurement device 10 and high color measurement accuracy. Further, since the coefficient of the conversion formula is calculated from the measured values of the colors of the three reference lights having colors in the vicinity of the inspection target light, it is possible to improve the color measurement accuracy in a range where the measured values are concentrated in the inspection. it can.

  In addition, each of the three reference lights is light whose color measurement value acquired by the spectral color measuring device 20 is an outer edge or an internal color of an inspection standard indicating a color range related to the inspection of the inspection target light. . Thereby, the measurement accuracy of the color about the light which suits inspection standard can be raised.

  In addition, any one of the three reference lights is a light whose color measurement value acquired by the spectroscopic color measurement device 20 is the color of the center of the inspection standard indicating the color range related to the inspection of the inspection target light. It is. Thereby, the measurement accuracy of the color at the center of the inspection standard can be particularly improved.

  In addition, at least one of the three reference lights may be any of the colors of the outer edge of the inspection standard in which the measurement value of the color acquired by the second color measurement unit indicates the color range related to the inspection of the inspection target light. It is. As a result, the measurement accuracy of the color of the outer edge of the inspection standard can be particularly increased, and the suitability of the inspection target light to the inspection standard can be determined with high accuracy.

  The color range indicated by the inspection standard is the color range indicated by the MacAdam ellipse Step 3, and the center color of the inspection standard is the center color of the MacAdam ellipse Step 3. Accordingly, it is possible to determine with high accuracy whether or not the color of the inspection target light is in a range in which the possibility of recognizing a color difference from the center color of the inspection standard is low.

  Further, each of the three reference lights is light emitted in a different direction from one light source 40 including the organic light emitting layer 44. Thereby, the reference light of a several different color can be easily produced | generated using a single organic light emission means.

  The spectroscopic color measurement device 20 acquires a measured value of the color of the incident light from an integral value of a product of a spectrum obtained by spectrally dividing the incident light and a color matching function. Thereby, the coefficient of the conversion formula calculated in the coefficient calculation step can be corrected with high accuracy.

  In addition, the stimulus value direct-reading color measurement device 10 as the color inspection device of the present embodiment includes the three light detection units corresponding to the incidence of light on the three light detection units 13 having different wavelength characteristics of light detection sensitivity. A first color measurement unit that obtains a measurement value of the color of the incident light from the output of 13, the first color measurement unit, and the same color system as the measurement value by the first color measurement unit Colors of three reference lights having colors in the vicinity of the light to be inspected and different from each other by each of the spectral color measurement devices 20 that acquire the measurement value of the color of the light with higher accuracy than the first color measurement unit. The conversion formula coefficients calculated based on the measured values are converted into measured values of the three reference light colors obtained by the first color measuring means into measured values obtained by the spectral color measuring device 20, respectively. RAM 16 for storing the coefficient of the conversion formula to be used and the first color measuring means Is converted by the conversion equation measurements color 査 target light comprises a CPU15 to correct the measured value. Thereby, a highly accurate color inspection can be performed easily and in a short time. Further, since the stimulus value direct-reading color measurement apparatus 10 can acquire measurement values (R, G, B) without performing complicated processing on the output of the light detection unit 13, it measures the color in a short time. be able to. In addition, it is possible to measure the color by making incident light incident on the color filter 11 of the light detection unit 13. Since there are few restrictions on the luminous flux of the incident light, measurement is performed in a larger area than the spectral color measuring device 20. Can do.

(Modification)
Next, a modification of the above embodiment will be described.
In the above embodiment, an example has been described in which three reference lights having different colors are measured by the stimulus value direct-reading color measuring device 10 and the spectral color measuring device 20 and the coefficient of the conversion equation is calculated from the measured values. In the modification, the coefficient of the conversion formula is calculated from the measured values of the reference light of at least four different colors. Since the other points are the same as in the above embodiment, differences from the above embodiment will be described below.

In this modification, steps S11 and S12 of the conversion formula acquisition process shown in FIG. 6 are executed for at least four reference lights of different colors, and the measurement values (R ( i), G (i), B (i)) and measured values (X (i), Y (i), Z (i)) by the spectral color measuring device 20 are acquired. Then, the coefficient of the conversion formula is calculated by the least square method based on the acquired measurement value.
That, _X r to the following formula _{ε x (i), ε y} (i), the sum squared epsilon _z (i) to a _{minimum, X g, X b, Y} r, Y g, Y b, Z r , Z _g , Z _b are calculated. In this modification, i is an integer of 1 to N (N is an integer of 4 or more indicating the number of reference lights to be measured).
_{X (i) = X r ·} R (i) + X g · G (i) + X b · B (i) + ε x (i)
_{Y (i) = Y r ·} R (i) + Y g · G (i) + Y b · B (i) + ε y (i)
_{Z (i) = Z r ·} R (i) + Z g · G (i) + Z b · B (i) + ε z (i)

epsilon _x formula the sum of squares from the ones obtained by partially differentiating X _r is 0 _{(i) (1)} is derived.

Similarly, the following formulas (2) and (3) are derived because the sum of the squares of ε _x (i) is partially differentiated by X _g and X _b and becomes 0.

X _r , X _g , and X _b are calculated from a ternary simultaneous linear equation composed of the above equations (1) to (3).
For ε _y (i) and ε _z (i), Y _r , Y _g , Y _b , and Z _r , Z _g , Z _b are derived by deriving equations corresponding to equations (1) to (3), respectively. Is calculated.

  As described above, in this modification, at least four reference light colors are measured in the reference light measurement step, and in the coefficient calculation step, at least four reference light color stimulus value direct-reading color measurement in the reference light measurement step is performed. Coefficients of conversion equations for converting measured values obtained by the apparatus 10 into approximate values of measured values obtained by the spectral color measuring apparatus 20 are calculated by the least square method. As a result, the acquired conversion formula can convert at least four reference light measurement values of the stimulus value direct-reading color measurement device 10 into approximate values of the measurement values of the spectral color measurement device 20, respectively. In addition, for the color near the color of the reference light used for the calculation, the measurement value obtained by the stimulus value direct-reading color measurement device 10 can be corrected with high accuracy. The part to be done can be increased.

The present invention is not limited to the above embodiments and modifications, and various modifications can be made.
For example, in the above-described embodiment and the modification, the example in which the inspection standard is the MacAdam ellipse Step 3 on the xy chromaticity diagram has been described. However, the inspection standard is not limited to this, and the MacAdam ellipse Step 1 or the like depending on the inspection target or purpose. The MacAdam ellipse Step 2, the MacAdam ellipse Step 4, or a larger MacAdam ellipse may be used as the inspection standard. When the inspection standard is MacAdam ellipse StepN (N is a natural number), the color range in the vicinity of the inspection standard is, for example, a predetermined number times (1.2 times, 1.5 times, etc.) of the MacAdam ellipse StepN. ), The range represented on the inside or on the outer edge of the ellipse.
Further, a specific range on the xy chromaticity diagram may be used as the inspection standard without using the MacAdam ellipse. In this case, the center color of the inspection standard may be a color corresponding to the center of gravity of the figure representing the shape on the xy chromaticity diagram of the inspection standard, for example. The color range in the vicinity of the inspection standard is, for example, a predetermined number times (1.2 times, 1.5 times) the size of the position vector indicating the position of each point on the outer edge with the center of the inspection standard range as the origin. Etc.) can be on the inside or on the outer edge of the range represented by the point indicated by the position vector obtained.
The color range indicated by the inspection standard is a color system (for example, xyY color system, L ^* a ^* b) that can be converted from the color measurement values obtained by the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20. ^{* A} color system, etc., or a part of the elements of the color system (for example, chromaticity (hue and saturation) represented by xy in the xyY color system), L ^* a ^* b ^* may be represented by a ^* b ^* represented chromaticity, etc.) of the color system.

Moreover, in the said embodiment and modification, using the tristimulus value of an XYZ color system as a color measurement value, the tristimulus value of the reference light acquired with the stimulus value direct-reading type color measuring device 10 and the spectral color measuring device 20 Although the coefficient of the conversion formula was calculated from the measured value representing, the present invention is not limited to this. The color measurement values by the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20 are values of other arbitrary color systems that express the color by three elements, for example, L ^* a ^* b ^* color system, It may be a value such as L ^* u ^* v ^* color system, L ^* C ^* h color system, xyY color system. The measurement value in the other arbitrary color system may be obtained by converting the tristimulus values of the XYZ color system acquired by the stimulus value direct-reading color measurement device 10 and the spectral color measurement device 20, for example. Good.

  In the above-described embodiment and the modification, the example in which the coefficient of the conversion formula is calculated by the information processing device 30 has been described. However, the present invention is not limited to this example. A coefficient may be calculated. In this case, the functions of the information processing device 30 are integrated into the stimulus value direct-reading color measuring device 10, and the stimulus value direct-reading color measuring device 10 and the spectral color measuring device 20 directly connected via the interfaces 18 and 27 are used. A color inspection system may be configured.

  In the embodiment and the modification, the example in which a plurality of different colors of reference light are obtained by changing the emission angle θ of the light from the light source 40 has been described. Light from a plurality of light sources 40 having different colors may be used as reference light.

  Moreover, although the light source 40 which inject | emits reference light and inspection object light demonstrated the example which consists of an organic light-emitting device in the said embodiment and modification, it is not the meaning limited to this, Arbitrary light-emitting devices which emit visible light are mentioned. It can be used as the light source 40.

  Moreover, although the example which test | inspects by the one stimulus value direct-reading type color measuring device 10 was demonstrated in the said embodiment and modification, it is not the meaning limited to this. For example, the conversion formula acquisition processing shown in FIG. 6 is performed for each of the plurality of stimulus value direct-reading color measurement devices 10 using the single spectral color measurement device 20 to calculate the coefficient of the conversion formula, and the obtained conversion formula May be stored in the RAM 16 of each stimulus value direct-reading color measuring apparatus 10. By doing in this way, even when the wavelength characteristics of the light detection sensitivity of the light detection unit 13 included in each stimulus value direct-reading color measurement device 10 are different from each other, between different stimulus value direct-reading color measurement devices 10. The error of the measured value can be reduced. Therefore, an accurate color inspection using the plurality of stimulus value direct-reading color measuring devices 10 can be performed easily and in a short time.

  Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, and includes the scope of the invention described in the claims and equivalents thereof. .

1 color inspection system 10 Stimulus value direct reading type color measuring device 11R, 11G, 11B Color filter 12R, 12G, 12B Light receiving unit 13R, 13G, 13B Photodetecting unit 14 ADC
15 CPU
16 RAM
17 ROM
18 Interface 19 Bus 20 Spectroscopic Color Measurement Device 21 Diffraction Grating 22 Light Receiving Section 23 ADC
24 CPU
25 RAM
26 ROM
27 Interface 28 Bus 30 Information processing device 31 CPU
32 RAM
33 Storage Unit 34 Interface 35 Operation Input Unit 36 Display Unit 37 Bus 40 Light Source 41, 42 Sealing Glass 43 Anode 44 Organic Light-Emitting Layer 45 Cathode 46 Photocurable Adhesive

Claims (9)

A color inspection method for inspecting colors,
First color measurement means for obtaining a measurement value of the color of the incident light from the outputs of the three light detection units according to the incidence of light on three light detection units having different wavelength characteristics of light detection sensitivity; And each of the second color measuring means that obtains the measured value of the color of the light with higher accuracy than the first color measuring means in the same color system as the measured value by the first color measuring means. A reference light measurement step for obtaining measured values of at least three reference light colors having colors in the vicinity of the light and having different colors from each other;
In the reference light measuring step, the measured values of the colors of the at least three reference lights obtained by the first color measuring means are converted into measured values by the second color measuring means or approximate values of the measured values, respectively. A coefficient calculation step for calculating the coefficient of the conversion formula;
An inspection object light measurement step of obtaining a measurement value of the color of the inspection object light by the first color measurement means;
A correction step of correcting the measurement value by converting the measurement value of the color in the inspection object light measurement step by the conversion formula,
A color inspection method comprising:   Each of the at least three reference lights is a light whose color measurement value acquired by the second color measuring means is an outer edge or an inner color of an inspection standard indicating a color range related to the inspection of the inspection target light. The color inspection method according to claim 1, wherein:   Any one of the at least three reference lights includes a color measured by the second color measuring unit and a center color of an inspection standard indicating a color range related to the inspection of the inspection target light. The color inspection method according to claim 1, wherein the color inspection method is light.   At least one of the at least three reference lights is a color of an outer edge of an inspection standard in which a measurement value of a color acquired by the second color measurement unit indicates a color range related to the inspection of the inspection target light. The color inspection method according to claim 1, wherein the light is any one of the following.   5. The color range indicated by the inspection standard is a color range indicated by a MacAdam ellipse Step 3, and the center color of the inspection standard is a center color of the MacAdam ellipse Step 3. The color inspection method according to any one of the above.   6. The color inspection according to claim 1, wherein each of the at least three reference lights is light emitted in a different direction from one organic light emitting unit including an organic light emitting layer. Method. In the reference light measurement step, at least four colors of the reference light are measured,
In the coefficient calculating step, the measured values by the first color measuring means of the colors of the at least four reference lights in the reference light measuring step are converted into approximate values of the measured values by the second color measuring means, respectively. The color inspection method according to claim 1, wherein a coefficient of the conversion formula is calculated by a least square method.   The second color measuring means acquires a measured value of the color of the incident light from an integral value of a product of a spectrum obtained by spectrally dividing the incident light and a color matching function. The color inspection method according to any one of 1 to 7. A color inspection device for inspecting colors,
First color measuring means for obtaining a measured value of the color of the incident light from the outputs of the three light detecting sections according to the incidence of light on three light detecting sections having different wavelength characteristics of light detection sensitivity; ,
The second color that obtains the measurement value of the color of the light with higher accuracy than the first color measurement unit in the same color system as the measurement value by the first color measurement unit and the first color measurement unit. A coefficient of a conversion formula calculated based on measured values of colors of at least three reference lights each having a color in the vicinity of the inspection target light and different from each other by each of the measurement means, the first color measurement Storage means for storing coefficients of conversion equations for converting the measured values of the colors of the at least three reference lights obtained by the means into measured values by the second color measuring means or approximate values of the measured values, respectively;
Correction means for converting the measurement value of the color of the inspection object light by the first color measurement means by the conversion formula and correcting the measurement value;
A color inspection apparatus comprising:

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