JP2001228025A - Method and instrument for measuring rovibond color - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring Rovibond color with which Rovibond color can easily be evaluated objectively. SOLUTION: A method for finding the number of a standard color filter equivalent to the color of a sample, includes a measuring step (S14) of collecting the transmissivity spectral data of the sample and a calculating step (S16) of finding the number of the standard color filter equivalent to the color of the sample, by minimizing the difference between the chromaticity coordinates of the sample and the chromaticity coordinates corresponding to each color obtained, by converting the calculus indicating the relation between the absorbance spectrum of Rovibond color at an arbitrary number and the absorption spectrum of each standard color filter at a reference number.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring lovibond color, and more particularly to a method and apparatus for measuring lovibond color that can objectively and easily evaluate lovibond color.

[0002]

2. Description of the Related Art Heretofore, a color test of fats and oils has been carried out to determine a value (number) of a standard color glass (filter) equivalent to the color of a sample fat and oil using, for example, a Lovibond colorimeter. The measurement of the lobibond color is performed according to JIS K 3503-196.
2 In this standard, a person is to visually inspect the color of a sample. JIS K 35
According to 03-1962, natural light source (Northern dispersed sunlight)
Alternatively, an artificial light source (60 W pearl OSRAM lamp) is used as a light source.

[0003] Then, using illumination light from the light source, a person visually selects a standard color glass (filter) so that the color of the standard glass filter matches the color of the sample put in the cell having the determined optical path length. I do. The color of the sample is to be tested based on the filter number and the optical path length. By the way, the standard color glass (filter) used for the Lovibond color test is a glass substrate coated with a coloring agent in proportion to the number. In addition, when two filters of the same color are overlapped, the filter becomes the same color as the filter of the sum of those numbers. For example, red filter No. 5 + red filter No. 3 becomes red filter No. 8.

[0004] These contents indicate that filters of a specific color have the same absorption spectrum, and the number indicates the relative absorbance of the absorption spectrum. Also,
When filters of the same number of red, yellow, and blue are superimposed, the color becomes the neutral color of that number, so in principle, the target color can be represented only by the filter set of three colors of red, yellow, and blue. Become. Conventionally, it has been common for a person to visually evaluate the lovibond color in this way.

[0005]

However, the above method of visual inspection by a person has the following problems. (1) Individual differences appear between persons to be examined, and the results are not always the same. (2) A temporal change of the glass filter cannot be corrected. (3) It is necessary to have trained inspectors. The present invention has been made in view of the circumstances of the related art, and an object of the present invention is to provide a method and an apparatus for measuring a lovibond color that can objectively and easily evaluate a lovibond color.

[0006]

In order to achieve the above object, a method for measuring lobibond color according to the present invention comprises a measuring step and a calculating step. here,
In the measuring step, transmittance spectrum data of the sample is collected. Further, the calculation step obtains chromaticity coordinates from the transmittance spectrum data of the sample obtained in the measurement step, the chromaticity coordinates of the sample, and each of the absorbance spectrum of the Robibond color at an arbitrary number versus the reference number. In a method of minimizing the difference between the corresponding chromaticity coordinates obtained by converting the calculation formula indicating the relationship with the absorbance spectrum of the standard color filter to the transmittance spectrum, the standard color filter equivalent to the color of the sample is used. Find the number.

In the present invention, a calculation formula showing the relationship between the absorbance spectrum of the Robibond color at the arbitrary number and the absorbance spectrum of each standard color filter of the reference number is as follows.

## EQU3 ## L (n_y, N_r, N_b) = Y ・ n_y+ R · n_r
+ B · n_b  (Where L (n_y, N_r, N_b) Means n_y,
n_r, N_bAbsorbance spectrum of lobibond color of y,
r and b are absorbance spectra of each standard color filter of the reference number
), And the calculating step is a step of measuring the transmittance of the sample.
Color stimulus value X obtained from torque data _S, Y_S, Z_SAnd on
Color stimulus value obtained by converting notation 3 into transmittance spectrum
X_L, Y_L, Z_LAnd the difference ((X_S-X_L)²+ (Y_S―
Y_L)²+ (Z_S―Z_L)²) In a way that minimizes
The standard color filter number n_y, N_r, N_bSeeking
Is preferred.

Further, in the present invention, there is provided a calculation condition setting step, wherein the calculation step weights the transmittance spectrum data obtained in the measurement step by the relative spectral distribution of light designated in the calculation condition setting step. It is also preferable to obtain the chromaticity coordinates of the sample under the designated light. here,
The calculation condition setting step specifies relative spectral distribution information of light used for the Lovibond color calculation.

According to another aspect of the present invention, there is provided a lovibond color measuring apparatus including a measuring unit and a calculating unit. Here, the measuring means collects transmittance spectrum data of the sample. Also,
The calculating means obtains chromaticity coordinates from the transmittance spectrum data of the sample obtained by the measuring means, the chromaticity coordinates of the sample and the absorbance spectrum of the Lovibond color at an arbitrary number versus each standard color of the reference number. In the method of minimizing the error with each corresponding chromaticity coordinate obtained by converting the calculation formula indicating the relationship with the absorbance spectrum of the filter to the transmittance spectrum, the number of the standard color filter equivalent to the color of the sample is obtained. Ask.

In the present invention, a calculation formula showing the relationship between the absorbance spectrum of the arbitrary Lovibond color and the absorbance spectrum of each standard color filter of the reference number is as follows.

L (n)_y, N_r, N_b) = Y ・ n_y+ R · n_r
+ B · n_b  (Where L (n_y, N_r, N_b) Means n_y,
n_r, N_bAbsorbance spectrum of lobibond color of y,
r and b are absorbance spectra of each standard color filter of the reference number
), And the calculating means calculates the transmittance spec of the sample.
Color stimulus value X obtained from torque data _S, Y_S, Z_SAnd on
Color stimulus value obtained by converting notation 4 into a transmittance spectrum
X_L, Y_L, Z_LAnd the difference ((X_S-X_L)²+ (Y_S―
Y_L)²+ (Z_S―Z_L)²) In a way that minimizes
The standard color filter number n_y, N_r, N_bSeeking
Is preferred.

Further, in the present invention, there is provided a data storage means, a calculation condition setting means, and a calculation information storage means, wherein the calculation means calculates the relative spectral distribution of the light specified by the calculation condition setting means. It is also preferable that the transmittance spectrum data of the data storage means is weighted to obtain the chromaticity coordinates of the sample under the designated light. Here, the data storage means stores transmittance spectrum data of the sample.

Further, the calculation condition setting means specifies a relative spectral distribution of light used for the Lovibond color calculation. The calculation information storage means stores information on the above equation (4).
The standard color filter referred to here is, for example, a yellow filter,
Red filter, blue filter, etc.

The reference number referred to here is, for example, number 1. In the calculation condition setting step and means described herein, for example, in addition to the relative spectral distribution of light used for the Robibond color calculation, if there are other conditions necessary for the Robibond color calculation, for example, the color system, viewing angle, wavelength The interval and the like can be set. The relative spectral distribution here refers to, for example, the relative value of the light intensity at each wavelength, based on the light intensity at a specific wavelength of the designated light.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A simple embodiment will be described.First embodiment  FIG. 1 shows a Lobibond colorimeter according to the first embodiment of the present invention.
The setting device is shown. Lobibond color measurement device shown in the figure
The device 10 includes a spectrophotometer (measuring means) 12 and a computer.
(Computing means) 14. Here, the spectrophotometer 1
2 is a light source 16 for measurement, a spectroscope 18, and a detector 20.
And the transmittance value of the sample 22 based on the output value of the detector 20.
Spectroscopic data can be collected.

The spectroscope 18 obtains a desired monochromatic light from the light from the light source 16. The detector 20 detects the intensity of light transmitted through the sample 22. Further, the computer 14 includes a data storage unit 24, a CPU 26, and a calculation information storage unit 28. Here, the data storage means 24 stores the transmittance spectrum data of the sample obtained using the spectrophotometer 12.

The CPU 26 calculates the sample 22 from the transmittance spectrum data of the data storage means 16 by calculation.
Find the number of the standard color filter equivalent to the color of. That is, the CPU 26 first obtains the tristimulus values X _S , Y _S , and Z _S from the transmittance spectrum data of the sample in the data storage unit 24.

Next, the CPU 26 converts the tristimulus values X _S , Y _S , and Z _{S of} the sample thus obtained and the equation (5) into a transmittance spectrum. stimulus values _{X L,} Y _L, the difference between ^{_{Z L ((X S -X L}} ) 2 + (Y S -
Y _L) ² + a _(Z S _-Z ^{L) 2)} in a manner that minimizes obtain the yellow filter as standard color filter, red filter, number _n y of the blue _filter, n r, the _{n b.}

In the present embodiment, the sample 22
Find the numbers of the yellow, red, and blue filters that are equivalent to the color of.

L (n)_y, N_r, N_b) = Y ・ n_y+ R · n_r
+ B · n_b  Here, L (n_y, N_r, N_b) Has yellow, red and blue numbers
Each n_y, N_r, N_bAbsorbance spectrum of lobibond color
Means kutor. y, r, and b are yellow, red, and blue, respectively.
3 shows the absorbance spectrum of the first filter. In addition, the real
In the embodiment, information on the calculation formula of Expression 5 above, for example,
Absorbance spectrum of the first yellow, red and blue filters
Are also stored in the calculation information storage means 28 in advance.
You.

The light emitted from the measurement light source 16 is
Information on the relative spectral distribution of the intensity at each wavelength, based on the light intensity of a specific wavelength, is stored in the spectral distribution information storage means 30. In the present embodiment, the calculation condition setting means 32 enables specification of a color system, a viewing angle, a wavelength interval, a standard color filter, and the like, which are necessary for calculating the Lovibond color. The wavelength scanning of the spectroscope 18 is controlled by the computer 26 and the wavelength scanning means 33.

Lobibond according to the first embodiment of the present invention
The color measuring device 10 is configured as described above.
Will be described with reference to FIG. First, measurement
The condition and the Lovibond color calculation condition are set (S1
0).Measurement condition setting  For example, the measurement range is 380 nm to 780 nm,
An interval of 1 nm can be set.

[0021]Lovibond color calculation condition setting  Color System Select the color system that represents the Lovibond color. For example, XY
Selectable from Z and xyY. Viewing angle Obtain Lobibond color from transmittance spectrum data of sample
Select the viewing angle for Viewing angle to observer's eyes
Select the corner to stretch. Eg 2 degrees field of view and 10 degrees
Selectable from the field of view.

Cell Length The cell length is selected for obtaining the lovibond color from the transmittance spectrum data of the sample. Here, when the measurement cell length is different from the Lobibond color calculation cell length, the measurement cell length is converted to the Lobibond color calculation cell length. The measurement cell length is, for example, 3.
18mm, 6.35mm, 12.7mm, 25.4m
m, 50.8 mm, 133.4 mm, etc. can be selected. Standard Color Filter A standard color filter expressing the Lovibond color of a sample can be basically selected from R: red filter, Y: yellow filter, and B: blue filter.

[0023]Baseline setting (measurement)  Baselines are inherently device-specific,
If measured, measurement conditions such as response and scanning speed
There is a subtle difference in the setting method. Therefore, this embodiment
In order to obtain an accurate spectrum, the actual spectrum
Baseline is measured and set under the same conditions as
(S12). This ensures the correct spectrum of the sample
Is given.

[0024]Sample measurement  With the spectrophotometer 12, for example, the measurement range is 380 nm to 7
At 80 nm and at a data acquisition interval of 1 nm, the transmittance
The spectrum data is obtained (S14). Y10, R20, B
FIG. 3 shows an example of the transmittance spectrum of the Lobibond color sample No. 5
Shown in Transmission spectrum data of such a sample 22
Is stored in the data storage means 24. After measurement,
The data 14 calculates Lobibond color based on the measurement result.
Now.

[0025]Lobibond color calculation  First, the CPU 26 transmits the sample through the data storage unit 24.
Tristimulus value X from rate spectrum data_S, Y_S, Z_SSeeking
(S16). Next, compare to the calculation information storage means 28
For example, Y1, as shown in FIG. 4I, R1, as shown in FIG.
The absorbance spectrum data of B1 as shown in FIG.
If collected, the equation of Equation 5 above is expressed in absorbance units.
Therefore, the CPU 26 converts this into a transmittance spectrum.
And the tristimulus values X, Y, Z in the used light source and the set visual field, etc.
Ask for. That is, in the present embodiment, the color of the human visual perception is
The values obtained here are based on transmittance, not absorbance.
Convert the absorbance spectrum to a transmittance spectrum,
From this tristimulus value X_L, Y_L, Z_LAsk for.

Next, the CPU 26 determines the transmittance of the sample.
Tristimulus value X obtained from spectrum _S, Y_S, Z_SWhen,
Tristimulus obtained by converting Equation 5 into a transmittance spectrum
Value X _L, Y_L, Z_LDifference ((X_S-X_L)²+ (Y_S―
Y_L)²+ (Z_S―Z_L)²Yellow) in a way that minimizes
Color filter, red filter, blue filter number n_y,
n_r, N_bIs obtained (S18). Thus, the sample 22
Collect the transmittance spectrum data, and
Calculated from the data, the yellow fill equivalent to the color of sample 22
Data, red filter, and blue filter numbers.
it can.

Here, as the minimizing method, any method can be used. For example, a simplex method or the like can be used. Also, any method can be used as a method of obtaining the initial value. For example, a yellow filter, a red filter, a blue filter, Filter numbers n _y , n _r , n
_b can be obtained.

As described above, according to the Lobibond color measuring apparatus 10 according to the first embodiment of the present invention, the spectrophotometer 12
Sampling the transmittance spectrum data of the sample 22, and calculating the numbers of the yellow, red, and blue filters equivalent to the color of the sample 22 by the above-described calculation from the obtained transmittance spectrum data of the sample 22. did.
As a result, the lovibond color can be objectively and easily evaluated as compared with the conventional method that is visually checked by a human.

In this embodiment, it is possible to perform remeasurement and recalculation every time the light source is changed. However, once the transmittance spectrum data of the sample is obtained by using the following, The color when the light source is changed can be obtained only by recalculation without actually changing the light source or the like and re-measuring. That is, in the first embodiment of the present invention,
It is difficult to analyze in detail how the color observed by the light source changes.

[0030] For example, when using a light source that approximates the spectral distribution of the D ₆₅ as a light source, only be estimated color visible when lighting daylight, if you want to know the color when subjected to illumination of other light In addition, it is necessary to change the light source to one that can obtain the desired illumination light, and perform a series of steps of remeasurement and recalculation from the beginning. Therefore, in the second embodiment of the present invention, once the transmittance spectrum data of the sample is once collected and stored using the spectrophotometer described below, the following calculation method is used to calculate the light source under various light sources. It is possible to accurately estimate the color at.

[0031]Second embodiment  FIG. 5 shows the Lobibond colorimetry according to the second embodiment of the present invention.
The schematic configuration of the setting device is shown. Note that FIG.
Corresponding parts are denoted by the reference numeral 100 and description thereof is omitted.
You. The Lobibond color measuring device shown in the figure is a spectrophotometer.
(Measurement unit) 112 and a computer 114 are included.

The spectrophotometer 112 includes a continuous light source 116,
It includes a spectroscope 118 and a detector 120. Here, the continuous light source 116 generates continuous light in a wavelength range to be measured. The spectroscope 118 obtains a desired monochromatic light from the light from the light source 116. The detector 120 detects the intensity of light transmitted through the sample 122. The computer 1
14 is a data storage unit 124, a CPU 126, a calculation information storage unit 128, and a spectral distribution information storage unit 130
And calculation condition setting means 132.

The data storage means 116 includes the detector 13
The transmittance spectrum data of the sample 122 based on the output value from the sample No. 6 is stored. The spectral distribution information storage means 130
Stores in advance the value of the light intensity at each wavelength, based on the light intensity at a specific wavelength, for example, of the light used for the Lobibond color calculation. For example, the light used for the Lobibond color calculation is JIS Z 8720-198.
3, standard light A, standard light D ₆₅ ,
An example in which the standard light C and the auxiliary standard light B are obtained is given as an example.

The calculation condition setting means 132 sets a color system, a viewing angle, a relative spectral distribution of light, a wavelength interval, and the like necessary for calculating the Lovibond color. This CPU 126
Includes a light source weighting unit 134 and a Lobibond color calculation unit 136. Then, the weighting unit 13 using the light source
Reference numeral 4 denotes a data storage unit 1 based on relative distribution information of designated light.
The transmittance spectrum data of 24 samples is weighted.
The Lobibond color calculation unit 136 first calculates tristimulus values X _S , Y _S , and Z _S from the transmittance spectrum data of the sample 122.

Next, the Lobibond color calculation unit 136
Are the tristimulus values X _S , Y _S , Z _S obtained from the transmittance spectrum data of the sample 122, and the tristimulus values X _L , Y _L , obtained by converting the following Expression 6 into a transmittance spectrum. the difference between the ^{_{Z L ((X S -X L}} ) 2 + (Y S -Y L) 2 + (Z S -Z
_L ) The numbers n _y , n _r , and n _b of the yellow filter, red filter, and blue filter are obtained by a method that minimizes ² ).

[0036]

L (n)_y, N_r, N_b) = Y ・ n_y+ R · n_r
+ B · n_b  Here, L (n_y, N_r, N_b) Has yellow, red and blue numbers
Each n_y, N_r, N_bAbsorbance spectrum of lobibond color
Means kutor. y, r, and b are yellow, red, and blue, respectively.
3 shows the absorbance spectrum of the first filter. In addition, the real
In the embodiment, the information on the above Equation 6 is
It is stored in the calculation information storage means 128.

The CPU 126 and the wavelength scanning means 133 change the wavelength selected in the spectroscope 118 at predetermined wavelength intervals, and adjust the wavelength of the spectroscope 118 so as to obtain transmittance spectrum data in a desired wavelength range. Control scanning. The Lobibond color measuring device 110 according to the second embodiment of the present invention is configured as described above, and its operation will be described below with reference to FIG.

In the present embodiment, the transmittance spectrum data of the sample has been collected in the data storage means 124 in advance. Then, when it is desired to know the color when the illumination of another color is performed, only the recalculation shown below need be performed without performing the re-measurement. For this reason, in the present embodiment, the CPU 1
26 is performed from the calculation condition setting (S110).

[0039]Lovibond color calculation condition setting  (1) Color system A color system for expressing the lovibond color is selected. For example, XY
Selectable from Z and xyY. (2) Light used for Lobibond color calculation When Lobibond color is determined from the transmittance spectrum of the sample
Specify the light. For example, JIS Z 8720-1983
Standard light A, standard light D specified in_{6 5}, Standard light C
And the auxiliary standard light B can be selected.

(3) Viewing Angle The viewing angle for obtaining the lovibond color from the transmittance spectrum of the sample is selected. Select the viewing angle and the angle to the observer's eyes. For example, it is possible to select from a 2 degree visual field and a 10 degree visual field. (4) Cell length The cell length is selected when obtaining the lovibond color from the transmittance spectrum of the sample. Here, when the measurement cell length is different from the Lobibond color calculation cell length, the measurement cell length is converted to the Lobibond color calculation cell length.

(5) Standard color filter A standard color filter for expressing the Lobibond color of the sample is selected. R: Red filter Y: Yellow filter B: Blue filter

[0042]Lobibond color calculation  (1) Weighting by Light Source The weighting unit 134 calculates relative spectral distribution information of the designated light.
, The transmittance spectrum data weight of the data storage means 24
The attachment is performed (S120). Note that the light used in this calculation is
Relative spectral distribution, that is, energy distribution
Defined standard light A, standard light D₆₅, Standard light C complement
An auxiliary standard light B or the like can be used as it is.

The weighting section 134 multiplies the transmittance spectrum by the relative intensity of each wavelength of the light specified in this way, and performs weighting by the light source, thereby transmitting the energy at each wavelength when the light source has the specified energy. Rate spectrum can be obtained. Then, the CPU 126 adds the weighted wavelengths to obtain transmittance spectrum data in a desired wavelength range, for example, 380 nm to 780 nm. Through this processing, a transmittance spectrum when the light source has the designated energy can be obtained.

The CPU 126 obtained in this manner
Tristimulus value from transmittance spectrum data of sample 122
X_S, Y_S, Z_SAsk for. Lobibond color calculator 136
Is the transmittance spectrum data obtained as described above.
Tristimulus value X obtained from_S, Y_S, Z_SAnd the above formula
Is converted into a transmittance spectrum to obtain a tristimulus value X._L,
Y_L, Z_LDifference ((X_S-X_L)²+ (Y_S-Y_L)²
+ (Z_S―Z_L)²) To minimize the standard color
Ruta number n _y, N_r, N_b(S116)

Here, when it is desired to know the color when another light is illuminated, the transmittance spectrum data is stored in the data storage means 124 without actually changing the light source and performing remeasurement and recalculation. Once collected, the color when the illumination light is changed can be obtained only by recalculation by the CPU 126 without actually changing the light source and performing remeasurement. Therefore, the color when viewed under other light can be estimated only by calculation.

Thus, according to the Lobibond color measuring apparatus 110 according to the present embodiment, the color when viewed with another light source can be more easily estimated as compared with a case without such a contrivance. As described above, according to the Lobibond color measuring apparatus 110 according to the second embodiment of the present invention, the transmittance spectrum data of the sample 122 is collected by the spectrophotometer 122, and By such calculation, the number of the standard color filter equivalent to the color of the sample 122 is determined.

As a result, similar to the first embodiment, the Lovibond color can be objectively and easily evaluated as compared with the conventional system visually checked by a human. Furthermore, according to the Lovibond color measurement device 110 according to the second embodiment of the present invention, if the transmittance spectrum data of the sample 122 is collected in the data storage unit 124 using the spectrophotometer 122, The computer 114 can recalculate the lovibond color of the sample from the obtained transmittance spectrum data of the sample according to the setting color system, the visual field, the relative intensity spectral distribution of light used for calculation, the wavelength interval, and the like.

As a result, according to the fluorescent object color measuring device 110 according to the second embodiment of the present invention, the accuracy of the test result and the reproducibility of the test result are improved because the fluorescent lamp is not affected by the deterioration of the light source lamp. Is achieved. That is, according to the Lobibond color measuring apparatus 110 according to the present embodiment, the transmittance spectrum data of the sample is once collected,
Once stored in 4, the color when the light is changed can be obtained only by recalculation without actually changing the light source and performing remeasurement. As a result, it is possible to estimate the color when viewed with other light only by calculation.

As a result, according to the Lovibond measuring device 110 according to the second embodiment, the color when viewed with another light source can be more easily estimated as compared with the first embodiment. In each of the above embodiments, an example using the XYZ color system has been described. However, the present invention is not limited to this, and other color systems can be used. Further, in each of the above-described configurations, an example has been described in which the calculation result of the Lovibond color is represented by a basic red filter, Y: a yellow filter, and B: a blue filter. However, the present invention is not limited to this. Even a color obtained by combining the filters can be re-expressed.

For example, the calculation result may be re-represented by N: neutral color, or, if three colors can be represented by two colors such as YB, for example, may be re-represented by the minimum basic color. When it is possible to re-express the calculation result of the Lovibond color in two colors such as YB, the number of the YB is set to a desired ratio,
For example, the expression can be fixed and fixed at 10: 1. For example, if the calculation result can be expressed using one color such as R in addition to two colors such as YB, the number of the two colors such as YB is fixed to a desired ratio, for example, 10: 1, and R or the like. May be expressed again.

[0051]

As described above, according to the method and apparatus for measuring lovibond color according to the present invention, transmittance spectrum data of a sample is collected (measuring step and measuring means), and the above-mentioned transmittance spectrum data is obtained from the transmittance spectrum data. The number of the standard color filter equivalent to the color of the sample is determined by the calculation formula (calculation step and calculation means). As a result, the lovibond color can be objectively and easily evaluated as compared with the conventional method that is visually checked by a human. According to the method and apparatus for measuring the lovibond color according to the present invention, by collecting and storing the transmittance spectrum data of the sample, the change in color when the light used for evaluating the lovibond color is changed is measured. After the relative spectral distribution of the light used for the Lovibond color calculation is designated without actually changing the illumination light and performing the re-measurement, the re-measurement can be performed only by the re-calculation. Therefore, it is possible to more easily evaluate the lovibond color as compared with the case where the conventional method using human eyes is used.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of a lobibond color measurement device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a processing flow of the Lobibond color measuring device shown in FIG.

FIG. 3 is an example of a transmittance spectrum of a Lobibond color sample of Y10, R20, and B5.

FIG. 4 is an example of an absorbance spectrum of each of standard filters Y1, R1, and B1.

FIG. 5 is an explanatory diagram of a schematic configuration of a Lobibond color measurement device according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a processing flow of the Lobibond color measuring device shown in FIG.

[Explanation of symbols]

 10, 110 ... Lovibond color measuring device 12, 112 ... spectrophotometer (measuring means) 14, 114 ... computer 24, 124 ... data storage means 26, 128 ... CPU (calculation means) 28, 128 ... calculation information storage means 30, 130: spectral distribution information storage means 32, 132 ... calculation condition setting means

Claims (6)

[Claims] 1. A method for determining the number of a standard color filter equivalent to the color of a sample, comprising: a measurement step of collecting transmittance spectrum data of the sample; and a chromaticity based on the transmittance spectrum data of the sample obtained in the measurement step. The coordinates are obtained, and the chromaticity coordinates of the sample are converted into a transmittance spectrum, which is a calculation formula indicating the relationship between the absorbance spectrum of the Lovibond color at an arbitrary number and the absorbance spectrum of each standard color filter of the reference number. And calculating a number of a standard color filter equivalent to the color of the sample by a method of minimizing a difference between each of the corresponding chromaticity coordinates. 2. The method according to claim 1, wherein
In the above, the absorbance spectrum of the Robibond color at any number
The relationship between the reference number and the absorbance spectrum of each standard color filter
The calculation formula indicating the relationship is as follows: L (n_y, N_r, N_b) = Y ・ n_y+ R · n_r
+ B · n_b  (Where L (n_y, N_r, N_b) Means n_y,
n_r, N_bAbsorbance spectrum of lobibond color of y,
r and b are absorbance spectra of each standard color filter of the reference number
), And the calculating step is performed based on the transmittance spectrum data of the sample.
Color stimulus value X obtained from _S, Y_S, Z_SAnd the above equation 1 is transmitted
Color stimulus value X obtained by conversion into a ratio spectrum_L, Y_L,
Z_LAnd the difference ((X_S-X_L)²+ (Y_S-Y_L)²+
(Z_S―Z_L)²) To minimize the standard color
Filter number n_y, N_r, N_bCharacterized by seeking
Robibond color measurement method. 3. The method for measuring lovibond color according to claim 1, further comprising: a calculation condition setting step of designating a relative spectral distribution of light used for the Lovibond color calculation, wherein the calculation step is specified in the calculation condition setting step. A method for determining the chromaticity coordinates of the sample under the designated light by weighting the transmittance spectrum data of the sample obtained in the measurement step according to the relative spectral distribution of the light. 4. A Lovibond color measuring apparatus for determining the number of a standard color filter equivalent to the color of a sample, comprising: measuring means for collecting transmittance spectrum data of the sample; and transmittance of the sample obtained by the measuring means. Calculate the chromaticity coordinates from the spectrum data, and calculate the relationship between the chromaticity coordinates of the sample and the absorbance spectrum of the Lovibond color at an arbitrary number versus the absorbance spectrum of each standard color filter of the reference number into a transmittance spectrum. Calculating means for determining the number of a standard color filter equivalent to the color of the sample by a method for minimizing the difference between the corresponding chromaticity coordinates obtained by the conversion, and a rovibond color measurement, apparatus. 5. The lobibond color measuring device according to claim 4,
In the above, the absorbance spectrum of the Robibond color at any number
The relationship between the reference number and the absorbance spectrum of each standard color filter
The formula for the relation is: L (n_y, N_r, N_b) = Y ・ n_y+ R · n_r
+ B · n_b  (Where L (n_y, N_r, N_b) Means n_y,
n_r, N_bAbsorbance spectrum of lobibond color of y,
r and b are absorbance spectra of each standard color filter of the reference number
), And the calculating means determines whether the transmittance spectrum data of the sample is
Color stimulus value X obtained from _S, Y_S, Z_SAnd above 2
Color stimulus value X obtained by conversion into a ratio spectrum_L, Y_L,
Z_LAnd the difference ((X_S-X_L)²+ (Y_S-Y_L)²+
(Z_S―Z_L)²) To minimize the standard color
Filter number n_y, N_r, N_bCharacterized by seeking
Robibond color measuring device. 6. The Lovibond color measuring apparatus according to claim 4, wherein a data storage means for storing transmittance spectrum data of the sample, and a calculation condition setting means for designating a relative spectral distribution of light used for the Lovibond color calculation. And calculation information storage means for storing information relating to the equation (2), wherein the calculation means weights the transmittance spectrum data of the data storage means with a relative spectral distribution of light specified by the calculation condition setting means. A lovibond color measuring device for obtaining chromaticity coordinates of the sample under the designated light.