JPS61292026A - Spectrocolorimeter - Google Patents

Abstract

PURPOSE:To decrease the number of parts without decreasing the accuracy of measurement by discretely processing the outputs from respective photoelectric transducers for a specific range among measuring wavelength regions and collectively processing the outputs from the plural photoelectric transducers for the other regions. CONSTITUTION:The outputs from the photoelectric transducers 13-16-13-24 corresponding to at least 560-590nm wavelength regions of a spectrocolorimeter which divides the reflected light or transmitted light from a material to be measured by a spectroscope and detects the light spactra thereof by plural pieces of the photoelectric transducer 13 installed for each of the prescribed measuring wavelength units are amplified by discrete amplifiers 14 (A6-A14). The outputs from the other wavelength regions are amplified simultaneously for each of the plural outputs by the amplifiers 14 (A1-A5, etc.). The tristimulus value and chromaticity of the object to be measured are calculated by using the discrete multiple value coefft. for the discrete wavelength regions and using the composite multiple value coefft. for the wavelength region combining the plural regions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spectrophotometer that calculates the tristimulus values and chromaticity of an object to be measured through arithmetic processing from each light spectrum value separated by a spectrometer.

[Prior Art] In recent years, there has been an increasing need to measure the colors of paints, prints, foods, cosmetics, etc., and the colors have been measured using various measuring instruments. Conventional colorimeters can be roughly divided into simple spectrophotometers that use an interference filter and self-recording spectrophotometers that use a spectrometer.

Simple spectrophotometers have advantages such as being easily miniaturized and inexpensive, but it has been impossible to accurately measure color quantitatively. On the other hand, in a self-recording spectrophotometer colorimeter,
Although it is possible to quantitatively and accurately measure color, the device is large and expensive.

Generally, in order to quantitatively display a color, the tristimulus values x, y, and z, which indicate the amount of three primary stimuli necessary to create the color to be measured by additive mixing, and the value of this color from the origin of the XYZ system coordinates are used. What is necessary is to find the chromaticity indicated by the coordinates (x, y, z) on the plane of a vector perpendicular to the plane of X+Y+7=1 formed in the coordinate system space.

Conventionally, a method for determining tristimulus values X, Y, Z and chromaticity is defined in JIS Z8722-1982 (method for measuring object color) as follows, for example. That is,
For example, the surface of the object to be measured is irradiated with standard light having spectral distribution characteristics predetermined according to JIS 28720 (standard light and standard light source for measurement), and the reflected light from the surface of the object to be measured is e.g. A spectrometer using a diffraction grating separates the light into each vector. Then, the spectral solid angle reflectance R(λ) of the standard light corresponding to each wavelength λ on the surface of the object to be measured is determined. FIG. 5 is a characteristic diagram showing the spectral solid angle reflectance R(λ) for wavelengths λ-38Onl'n to 780 nm in paint colors close to human skin. In the actual measurement equipment, λ-380nm to 780n
The spectral solid angle reflectance R(λ) at each wavelength λ is obtained by dividing the entire wavelength region of m into iQnm band widths.

When the spectral solid angle reflectance R(λ) at each wavelength λ for each wavelength interval of 10 nm is determined, the tristimulus values X, Y are obtained.

Z can be found using equations 1), (2), and (3), respectively.

Here, S(λ) is each wavelength λ for each 10 nm bandwidth of the standard light specified in Appendix 2 of JIS 28720.
These are the values of the spectral distribution at .

Furthermore, nu(λ) 1 anti(λ), 7(λ) are color matching functions regarding the XYZ source stimulus system, and S(λ) nu(λ), S(λ
)7(λ) and S(λ)7(λ) are respectively called charge coefficients, and are the values S of the standard spectral distribution of light at each wavelength λ.
(λ) and each color matching function Y(λ), y(λ), 7(λ)
It is a constant weighted by the intensity characteristics of the standard light source, etc. And the aforementioned JIS Z87
Table 1 of 22 (Method of Measuring Object Color) specifies the value of each charge coefficient for each wavelength λ of 10nI11 bandwidth.

Figure 6 shows the product of the charge coefficient at each wavelength λ obtained from the above JIS Table 1 and the spectral solid angle reflectance R(λ) at each wavelength λ obtained from Fig. 5 at lQnm wavelengths from 380 nm to 780 nm. It is plotted for each wavelength λ at intervals.

(1) , (2+ , (tristimulus value X in formula 31, ,
Once Y and Z are found, from these tristimulus values X, Y, and Z, XYZ
The chromaticity coordinates (x, y, z) of the color system are (4), (5)
, (calculated using formula 61.

x=X/ (X+Y+Z) ・=(4)
V=Y/ (X+Y+Z) ...(5
)z=Z/ (X0Y+Z) '-(6
) However, since x+y+z=1, it is actually (4
), (The chromaticities x and y may be determined using Equation 51.

On the other hand, in order to express color as an absolute quantity, the International Commission on Illumination (CIE) and JI
The characteristics are defined in S.

[Problems to be Solved by the Invention] However, even with a spectrophotometer configured to measure the color of an object to be measured in accordance with the above JIS standards, there are still the following problems that need to be improved. Ta.

That is, λ=380nl~7 set in the JIS standard
In order to obtain the spectral solid angle reflectance R〈λ〉 at each wavelength λ by dividing the entire wavelength of 80nl11 into lQnm band widths, a photoelectric conversion element formed of, for example, a photodiode etc. is divided into 40. , and 40 amplifiers are also required to amplify the values of each optical spectrum output from each photoelectric conversion element.

Furthermore, the spectral solid angle reflectance R at each of the obtained wavelengths λ
(λ) to the tristimulus values X, Y using equations (1), (2), and (3).

Since the calculation performed by the microcomputer to obtain Z becomes complicated, the calculation processing time increases. Therefore, not only does the number of constituent electronic components such as amplifiers increase, but also the calculations performed by the microcomputer become complicated, which increases the size of the entire device and increases manufacturing costs. In particular, each amplifier that amplifies the output signal of each photoelectric conversion element needs to suppress zero point movement to a minimum, so it is necessary to use a high precision and expensive amplifier.

On the other hand, in order to accurately measure the chromaticity X, y (4).

As shown in equation (5), X out of the tristimulus values X, Y, and Z.

Although it is necessary to obtain Y as accurately as possible, even if some error occurs in Z, the influence of the error on chromaticity x and y is small. That is, for example, in the characteristic diagram shown in FIG. 6 for each wavelength λ of the product of each charge coefficient and the spectral solid angle reflectance R(λ) for the aforementioned skin color, (1),
In order to obtain the stimulation value
Although it is necessary to accurately determine the spectral solid angle reflectance R (λ) within the wavelength range of 540 nm to 600 nm, it is necessary to accurately determine the spectral solid angle reflectance R (λ), but it is necessary to accurately determine the spectral solid angle reflectance R (λ). For the wavelength range from 440 nm to 480 nm, the spectral solid angle reflectance R (λ
) is not necessary.

Therefore, in the wavelength region where measurement accuracy is not so required, even if the spectral solid angle reflectance R(λ) is measured with a wide bandwidth exceeding 1Q nm wavelength, the calculation accuracy of the chromaticity x and y should not deteriorate significantly. .

How to use it: As mentioned above, in recent years, spectrophotometers have been increasingly used in the field rather than in the laboratory to control the quality of paint colors. A spectrophotometer used in such a field is required to be small, lightweight, inexpensive, and have a certain level of measurement accuracy.

Furthermore, in order to perform color measurement work on site, it is necessary to be able to easily and quickly perform the reading and measurement operations, including the calibration of the measured colors.

The present invention was made based on these circumstances, and its purpose is to calculate optical spectrum values with a wider bandwidth than the standard in a wavelength range that has little influence on the chromaticity calculation process. By measuring
It is an object of the present invention to provide a small and inexpensive spectrophotometer that can reduce the number of constituent electronic components such as amplifiers without significantly increasing measurement accuracy.

Yet another object of the invention is to provide a spectrophotometer that can automatically calibrate measured colors in addition to the above objects.

[Means for Solving the Problems] In the spectrophotometer of the present invention, the spectrophotometer is arranged on a spectral imaging plane of a spectrometer that separates reflected light or transmitted light from an object to be measured into optical spectra. At least 560 of each optical spectrum value for each predetermined measurement wavelength unit (approximately 10 nm wavelength width) in the measurement wavelength range measured by each photoelectric conversion element
The optical spectrum values for each of the predetermined measurement wavelength units output from each photoelectric conversion element corresponding to the wavelength range from nm to 590 nm are individually amplified, and 5 of the measurement wavelength ranges are amplified.
A plurality of adjacent photoelectric conversion elements corresponding to wavelength ranges other than the 60 nm to 590 nm wavelength range are connected in a composite manner as a set, and the composite optical spectrum values output from the plurality of photoelectric conversion elements that are compositely connected are respectively calculated. Furthermore, each weighting coefficient corresponding to a predetermined measurement wavelength unit (10 nm wavelength bandwidth) is used for each amplified optical spectrum value for each predetermined measurement wavelength unit, and the amplified composite light For spectrum values, tristimulus values and chromaticity are calculated using composite market price coefficients determined for each wavelength region corresponding to a plurality of complex-connected photoelectric conversion element sets.

In still another invention, in addition to the above invention, a commonly used standard white sample is disposed inside which is irradiated with the standard light from the photodetection section, and the photodetection section is always used except during the colorimetric work period for the object to be measured. A calibration cap is provided to cover the light input/output port of the spectrometer, and a shutter is provided at the entrance slit of the spectrometer, which is opened and closed at regular intervals during a certain period of time from the time the power is turned on until the start of color measurement work. Then, the arithmetic processing unit uses the black chromaticity obtained by the arithmetic processing unit during the period when the shutter is closed and the white chromaticity obtained by the arithmetic processing unit during the period when the shutter is open to The system automatically calibrates the measured values of the object to be measured.

[Function] With a spectrophotometer configured in this way, the tristimulus value
, Y, and Z, 560n has the most influence on the values of X and Y.
m to 590 rim wavelength region, each unit optical spectrum value in a predetermined measurement wavelength unit (10 nm bandwidth),
That is, the spectral solid angle reflectance R(λ) of 10 nm bandwidth
is calculated, and has almost no effect on the values of X and Y56
For wavelength regions other than the 0 nm to 590 nm wavelength region, a composite spectrum value with a bandwidth exceeding the 1Q nm wavelength bandwidth, that is, a spectral stereoscopic reflectance R(λ) exceeding the 10 nm pan I-width is determined. Then, for the spectral solid angle reflectance R(λ) of 1Qnm bandwidth, use the weighting coefficient corresponding to the 10nm bandwidth, and for the spectral solid angle reflectance R(λ) exceeding the 1Qnm bandwidth, use 10nm. Tristimulus values X, Y, Z and chromaticity x, y are calculated using composite market price coefficients set respectively corresponding to the bandwidth exceeding .

Another advantage of the invention is that in addition to the above-mentioned effects, the light input/output port of the photodetector is covered with a calibration cap except during the colorimetric work period, so that the spectrophotometer is powered on. The black chromaticity with the shutter closed and the white chromaticity with the commonly used standard white sample inside the calibration cap with the shutter open are automatically measured alternately.Using the measured values of these two standard colors, The measured values of the object to be measured during the measurement work period are automatically calibrated.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the general configuration of the spectrophotometer of the example, and 1 in the figure is a 20W light emitting device that emits standard light having spectral distribution characteristics close to standard light C specified in JIS 28720. It is a standard light source formed by a halogen lamp.

The standard light emitted from the standard light source 1 is guided to the photodetection probe 3 as a photodetection section via the irradiation fiber bundle 2a, and is arranged so as to come into contact with the tip 3a of the photodetection probe 3. The light is scattered and reflected on the surface of the object to be measured 4 and enters the entrance slit 6 of the spectrometer 5 via the light receiving fiber bundle 2b.

The photodetection probe 3 irradiates the standard light incident from the bundle of irradiation fibers 2a onto the surface of the object to be measured 4 that is in contact with the tip 3a at a predetermined incident angle, and also The scattered reflected light beam is received by a fiber bundle whose light entrance is directed perpendicularly to the surface of the object to be measured 4, and is outputted via the aforementioned light-receiving fiber bundle 2b.

The scattered reflected light from the surface of the object to be measured 4 enters the spectrometer 5 through the entrance slit 6 and enters the collimator 8 via the shutter 7, where it is converted into parallel light and is then entered into the diffraction grating 9. Ru. The light incident on this diffraction grating 9 is separated into each light spectrum, reflected by a concave mirror 10, and focused at a predetermined focal point. On this spectrum imaging plane 11, a photodiode array 12 consisting of 35 photoelectric conversion elements is arranged in the direction in which the wavelength λ of the optical spectrum changes. Simultaneously measure the optical spectrum value of λ.

In the example, the focal length of the spectrometer 5 is 150I, and the number of lines engraved per 111IWl of the diffraction grating 9 is 600, so the inverse dispersion of the spectrometer is about 1 Onm/lRm.

Therefore, the wavelength λ− on the spectral imaging plane 11
The light spectrum of 390nm has a wavelength of λ-730nn.
The distance to the + light spectrum is 35 mm. On the other hand, the width of the light receiving surface of each photoelectric conversion element forming the photoelectric conversion element 12 is approximately 1+m, so the total width of the photodiode array 12 consisting of 35 photoelectric conversion elements is 35 m.
m. Therefore, the bandwidth of the light spectrum irradiated to one photoelectric conversion element is approximately 10 nm, and it is possible to cover the wavelength range from 390 nm to 730 nm with 35 photoelectric conversion elements.

FIG. 2 is a circuit diagram showing the connection configuration of 35 photoelectric conversion elements 13 that constitute the photodiode array 12.
Table 1 is a table showing the wavelength λ and channel assignment of each photoelectric conversion element 13. Each photoelectric conversion element 13 numbered from 1 to 35 in the figure has a wavelength of 10r+ at every 10nm wavelength interval from λ=390nn+ to λ=730nm.
Each optical spectrum value of m bandwidths is detected and converted into an electrical signal. Then, 1 to 4 photoelectric detection elements 1 to which respective optical spectra from 390 ni wavelength to 410 ni wavelength are incident.
3 are connected in parallel, and the output signals output from each of the photoelectric conversion elements 13 connected in parallel are sent to channel C.
The signal is input as HI to the multiplexer 15 via the amplifier 14. Further, 5 to 7 photoelectric conversion elements 13 into which each optical spectrum of wavelengths from 430 nm to 450 nm is incident are connected in parallel, and the output signal is sent to another amplifier 1 as CH2.
4 to the multiplexer 15. In addition, each photoelectric conversion element 13 corresponding to a wavelength from 540 nm to 620 nm has one channel C.
H6 to H14 are formed and input to the multiplexer 15 via the amplifier 14, respectively. As shown in Table 1, in the embodiment, the output signals output from 35 photoelectric conversion elements 13 are integrated into 17 channels.

Table 1 At the multiplexer 15, the parallel signals input simultaneously from each of the amplifiers 14 are time-divided and converted into serial signals, which are further converted into digital signals at the A/D converter 16, and then sent to a microcomputer as an arithmetic processing section. 17. The microcomputer 17 calculates tristimulus values X, Y, Z and chromaticities X, y shown by equations (7) to (11).

x-X/ (X+Y+Z) -・
-(10)y=Y/ (X+Y+Z)
...(11) However, (7), +8),
Each market price coefficient S(λ) ball(λ), S(λ)y(
For the values of λ) and S(λ), the multi-values shown in Table 2 are used. That is, from λ=540nm (CH6) to λ-6
The values for each wavelength λ of each 10 nm bandwidth between 20 nm (CH14) are the same as those specified in Table 1 of JIS Z8722 mentioned above, but CH2-CH2 and CH
For CH15 to CH17, the JIS market price coefficient cannot be used as is, so JIS
A composite market price coefficient weighted by including the standard spectral distribution characteristics of light C specified in IS 28720 and the sensitivity characteristics of the photoelectric conversion element 13 is set. That is, 1
10n for a unit optical spectrum value of 0nm bandwidth
A market price coefficient corresponding to m wavelength width is used, and a composite market price coefficient is used for a composite optical spectrum value exceeding a 10 nm bandwidth. The determined tristimulus values X, Y, Z and chromaticity x, y are outputted from the output terminal 18.

In addition to the normal colorimetric switch 19, this microcomputer 17 also has the measured spectral solid angle reflectance R (
A black calibration switch 20 and a white calibration switch 21 are installed for calibration operation to obtain the actual number of λ).

Then, actually press the color measurement switch 19 to measure the object to be measured 4.
Before measuring the color, the black calibration switch 20 is pressed and the shutter 7 of the spectrometer 5 is moved to the position shown by the dotted line to block the incident light and enter the black color measurement state. Then, this black color is measured and the reflectance R'(λ) is stored in the storage section of the microcomputer 17 as the [O] level. Next, a reflectance R close to 1 is applied to the tip 3a of the light detection probe 3.
(λ) is brought into contact with the commonly used standard white sample 22 and the white calibration switch 21 is pressed. Then, the color of this commonly used standard white sample 22 is measured, and the reflectance R(λ) is stored in the microcomputer 17 as [1] level. The actual measured value is then calibrated from these two values.

The tristimulus values X, Y, and
The calculation results of Z and chromaticity x, y are shown below.

X,=34.788. Y-33,7232=25.94
3x=0.368 y=o, 3sy When this result was compared with the result measured with a self-recording spectrophotometer colorimeter, which is a high-end model, the error for tristimulus values X, Y, and Z was within 0.3. 1 chromaticity

Regarding y, there was agreement within an error of 0.002.

In this way, tristimulus values X, Y, Z and □ and chromaticity X.

It is possible to reduce the number of channels input to the multiplexer 15 from 40 in the conventional device to 17 in the embodiment without substantially reducing the measurement calculation accuracy of y.

Therefore, it is possible to reduce the number of amplifiers and amplifiers 14 that amplify the output signals of each photoelectric conversion element 13 forming the photodiode array 12, and also to reduce the number of channels input to the multiplexer 15, so that the configuration of the multiplexer 15 can also be reduced. It's easier and cheaper. Furthermore, the calculation of tristimulus values and chromaticity in the microcomputer 17 is also simplified by the reduction in the number of channels. Also,
The number of market price coefficient data that needs to be stored in a storage unit such as a ROM can be reduced. Therefore, the calculation processing time can be shortened and the microcomputer 17 itself can be downsized. Since the number of electronic components constituting the entire spectrophotometer can be reduced in this way, the entire device can be downsized and manufacturing costs can be reduced. In addition, in the spectrophotometer of the example, the shape of the spectrocolorimeter main body excluding the microcomputer 17 part is approximately A4 size in floor area and approximately 2Q in height.
It was possible to downsize to cm.

Table 3 shows the number of channels input to the multiplexer 15 and the assigned wavelength λ of each channel in another embodiment of the present invention.
This shows that. In this example, λ-540n
1Q for the wavelength range from m to λ = 590 nm
Determine each unit optical spectrum value with a nm bandwidth, and calculate this 54
1 for wavelength ranges that do not belong to 0 nm to 590 nm
Each composite light spectrum value is determined with a bandwidth exceeding the 0 self m band width. The total number of channels is further reduced from 17 in the previous embodiment to 15.

Therefore, each composite market value coefficient S(λ) or (λ), S(λ)7(λ) corresponding to each composite optical spectrum.

As shown in Table 3, the setting value of S(λ)7(λ) is also changed in the part corresponding to the wavelength λ whose bandwidth is widened.

Furthermore, Table 4 shows the number of channels input to the multiplexer 15 and the assigned wavelength λ of each channel according to yet another embodiment of the present invention.

In this example, λ=56OnlIl to λ=59
For the wavelength range up to 0 nm, each unit optical spectrum value is determined with a band width of 10 nm, and this 560 nm to 590 nm
For wavelength regions that do not belong to i, each composite light spectrum value is determined with a bandwidth exceeding 10 nm. Then, the total number of channels is set to 1 in Example 1 of Table 3.
The number has further decreased from 5 to 14.

In this way, the wavelength range measured with a 10 nm bandwidth is 56
Even if the wavelength was limited to 0 nm to 590 nm, measurement results comparable to those obtained using a self-recording spectrophotometer colorimeter, which is a high-end model, were obtained as in the above-mentioned examples. Therefore, since the number of channels can be significantly reduced, it is possible to further improve the above-mentioned effects.

FIG. 3 is a diagram showing a main part of a photodetection probe of a spectrophotometer according to another embodiment of the present invention. That is,
In the previous example, the reflectance R using black and white
(λ) is carried out by operating the black calibration switch 20 and white calibration switch 21 connected to the microcomputer 17.
0 and 21 to form a photodetection probe 3 as shown in the figure.
It is also possible to use a cylindrical calibration cab 23 that is placed over the tip 3a of the calibrator. A commonly used standard white sample 24 is attached to the bottom of the calibration cap 23.
3 is placed over the tip 3a of the photodetection probe 3, the commonly used standard white sample 24 is set at the regular position. The calibration cap 23 is always placed over the tip 3a during the period when the color of the object 4 to be measured is not measured. When the power is turned on, the microcomputer 17 automatically opens and closes the shutter 7 of the spectrometer 5 at regular intervals to automatically measure the level of reflectance R(λ). Also, shutter 7
The color of the commonly used standard white sample 24 of the calibration cap 23 is automatically measured during the period when ' is open. Commonly used standard white sample 2
4 has a reflectance close to 1, it can be confirmed through software in the microcomputer 17 that the reflected light from the commonly used standard white sample 24 has been input. Therefore, the measured value is automatically calibrated without any particular switch operation by the operator.

As described above, when the spectrophotometer is powered on, the measurement value of the object to be measured 4 during the measurement period is automatically calibrated by the action of the calibration gap 23 and the shutter 7.
The operator does not need to perform any particular calibration work before starting the color measurement work. Therefore, on-site measurement work can be carried out easily and in a short time.

Further, in the embodiment, a reflection type photodetection probe 3 is used as the photodetection section, but a transmission type photodetector 25 may be used as shown in FIG. 4. In FIG. 4, the standard light input from the irradiation fiber bundle 26a passes through the object to be measured 29 via the collimator 28 fixed by the cylindrical lens mount 27, and is input to the condenser 30. The transmitted light input to the condenser 30 is transmitted through the light receiving fiber bundle 26b.
is guided to the spectrometer 5 via the .

[Effects of the Invention] As explained above, according to the present invention, the optical spectrum 1H value is measured with a hand width wider than the standard in the wavelength range where the chromaticity calculation process is not affected and the degree of influence is small. ing. Therefore, the number of constituent electronic components such as amplifiers can be reduced without reducing measurement accuracy, and a compact and inexpensive spectrophotometer can be provided.

Furthermore, the measured colors are automatically calibrated.
The measurement work is simplified and can be carried out in a short time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the general configuration of a spectrophotometer according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing the main parts of the same embodiment, and FIG. A partial cross-sectional view showing the calibration cap and photodetection probe of the spectrophotometer of the example,
FIG. 4 is a partial sectional view showing a transmission type photodetector according to another embodiment, FIG. 5 is a spectral solid angle reflectance characteristic diagram, and FIG. 6 is a characteristic diagram of the product of market price coefficient and reflectance. . 1... Standard light source, 2a... Fiber bundle for irradiation, 2b
...Fiber bundle for light reception, 3...Photodetection probe, 3
a... Tip, 4... Object to be measured, 5... Spectrometer, 6... Entrance slit, 7... Shutter, 8...
・Collimator, 9... Diffraction grating, 10... Concave mirror,
DESCRIPTION OF SYMBOLS 11... Spectrum imaging plane, 12... Photodiode array, 13... Photoelectric conversion element, 14... Amplifier, 15... Multiplexer, 16... A/D converter, 17...・Microcomputer, 18...Output terminal, 19...Measuring switch, 20...Black calibration switch, 21...White calibration switch, 22.24...
・Common standard white sample, 23... Calibration cap, 25.
...Transmission type photodetector.

Claims (2)

[Claims] (1) A standard light source that emits standard light; a light detection unit that irradiates the measured object with the standard light emitted from the standard light source and obtains reflected light or transmitted light from the measured object; and the light detection section. a spectrometer that separates the reflected light or transmitted light obtained by the section into optical spectra using a diffraction grating; a plurality of photoelectric conversion elements that are arranged at and receive the light spectrum; determined by the spectral distribution characteristics and color matching function of the standard light from the light spectrum value for each of the predetermined measurement wavelength units obtained from the photoelectric conversion elements; In a spectrophotometer comprising an arithmetic processing unit that calculates tristimulus values and chromaticity of the object to be measured using weighted coefficients: At least 560 nm to 5 of the measurement wavelength range
a plurality of individual amplifying means for individually amplifying optical spectrum values for each of the predetermined measurement wavelength units output from each of the photoelectric conversion elements corresponding to the 90 nm wavelength region; A plurality of adjacent photoelectric conversion elements corresponding to the wavelength region are connected in a composite manner as a set, and a plurality of photoelectric conversion elements that commonly amplify a composite optical spectrum value outputted from each of the plurality of compositely connected photoelectric conversion elements are connected. common amplification means; using a weighting coefficient determined corresponding to each of the predetermined measurement wavelength units for the optical spectrum values for each of the predetermined measurement wavelength units obtained by each of the individual amplification means; , for each of the composite optical spectrum values obtained by each of the common amplification means, a composite weighting coefficient determined for each wavelength region corresponding to the set of the plurality of decoding-connected photoelectric conversion elements is used. and calculating means for calculating the tristimulus values and chromaticity. (2) a standard light source that emits standard light; a light detection unit that irradiates an object to be measured with the standard light emitted from the standard light source and obtains reflected light or transmitted light from the object; and the light detection section. a spectrometer that separates the reflected light or transmitted light obtained by the section into optical spectra using a diffraction grating; a plurality of photoelectric conversion elements that are arranged at and receive the light spectrum; determined by the spectral distribution characteristics and color matching function of the standard light from the light spectrum value for each of the predetermined measurement wavelength units obtained from the photoelectric conversion elements; In a spectrophotometer comprising an arithmetic processing unit that calculates tristimulus values and chromaticity of the object to be measured using weighted coefficients: At least 560 nm to 5 of the measurement wavelength range
a plurality of individual amplifying means for individually amplifying optical spectrum values for each of the predetermined measurement wavelength units output from each of the photoelectric conversion elements corresponding to the 90 nm wavelength region; A plurality of adjacent photoelectric conversion elements corresponding to the wavelength region are connected in a composite manner as a set, and a plurality of photoelectric conversion elements that commonly amplify a composite optical spectrum value outputted from each of the plurality of compositely connected photoelectric conversion elements are connected. common amplification means; using a weighting coefficient determined corresponding to each of the predetermined measurement wavelength units for the optical spectrum values for each of the predetermined measurement wavelength units obtained by each of the individual amplification means; , for each of the composite optical spectrum values obtained by each of the common amplification means, a composite weighting coefficient determined for each wavelength region corresponding to the set of the plurality of decoding-connected photoelectric conversion elements is used. calculation means for calculating the tristimulus values and chromaticity; a standard white sample for regular use to which the standard light from the light detection section is irradiated is disposed inside, and is not used except during the color measurement work period for the object to be measured; a calibration cap that is always placed over the light input/output port of the photodetector; a shutter provided at the entrance slit through which reflected light from the photodetector of the spectroscope is incident; and a calibration cap that is always placed over the light input/output port of the photodetector; shutter opening/closing means for opening and closing the shutter at a constant period during a certain period of time; A spectrometer characterized by comprising an automatic calibration means for automatically calibrating the measured value of the object to be measured obtained by the arithmetic processing section during the measurement work period using the white chromaticity obtained by the processing section. Color meter.