JPH09249000A - Color matching method of paint and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a very highly flexible system and obtain a paint formulation date, which shows the nearest matching properties to unknown color data by a method wherein a computer obtains an optimum formulation data by comparing received aim color data with the sample color data of a matched paint film. SOLUTION: This device has a three angular spectrometer consisting of a colorimeter 1 and a data displaying device, which communicates through a modem with a server computer device so as to display formulation data thereon. Further, this device is equipped with terminal computer devices 2 each having an electronic automatic metering device, which meters paint full colors on the basis of the formulation data in order to form a matched paint and a server computer device 3, which stores data sent from respective terminal computer devices 2 in a color match data base so as to retrieve the most closely resemble sample data in order to output the optimum formulation data. In this embodiment, a computer is composed of terminal computer devices 2 separately arranged and sever computer devices 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint color matching method and apparatus, and more particularly to storing data representing an unknown color of a target color object and the surface temperature of the color object, For example, a paint formulation that uses a colorimeter that is easy to use by connecting directly to the computer via hardwire, yet constitutes a system that is extremely flexible, and that has the closest match to the color data of the unknown color. The present invention relates to a paint color matching method and device.

[0002]

2. Description of the Related Art A color matching system using a computer is disclosed in, for example, US Pat. No. 3,601,589.
It is known as described in the specification. In said U.S. patent, the total spectral reflectance of an unknown color panel is determined by a scanning spectrophotometer and this reflectance data is sent to a computer, which is the pure pigment K and S.
A method of mathematically processing prestored data representing values (representing absorption and dispersion, respectively) to provide a logical color match is disclosed.

The disclosure content of the above-mentioned US patent is basically
It concerns a set of calculation procedures. That is, according to this calculation means, K (absorption) and S
(Dispersion) can be calculated, and furthermore, for a set of pure pigments, the K and S values of the pigment combination are equal to the K and S values of the unknown color for each wavelength of the set. Can be determined. This is the basic color matching algorithm that is also used by other spectrophotometric color matching systems.

The problems with the above system are firstly very expensive and difficult to maintain, and secondly,
A logical color matching is performed using the data obtained for unknown and known pure pigments of unknown color. That is, the final color obtained by mixing the pigments according to the calculated color value may be different from the unknown color. Therefore, the color matching formula is usually a first-order mathematical approximation method, and it is necessary to correct and adjust the software which is a part of the system.

To improve the system, for example,
JP-A-63-153677 (US Pat. No. 4,811)
(Corresponding to No. 3,000), the portable color meter is used to analyze the selected color, and color data representing hue, saturation, and brightness of the selected color is stored, and the color in the color meter is stored. The data is connected to a computer, a plurality of available color formulas are stored in the computer, and color data representing the hue, saturation, and brightness of each paint specified by the stored available color formula is stored in the computer. Comparing the color data stored in the computer and received from the color meter with the stored color data representing each of the stored available color formulas to find the closest match and find the closest match. Method and apparatus for selecting a stored color formula represented by the emitted color data and thereby performing color matching for the selected color It has been proposed.

However, this patent publication does not take into consideration that the temperature of the object is simultaneously measured when analyzing the selected color. When the temperature of an object changes,
The color of the object also changes. This change is reversible and is known as thermochromism. Therefore, naturally, the colorimetric value obtained by measuring with the colorimeter also changes when the temperature of the object to be measured changes. The degree of change is not constant because it depends on the material forming the color of the object.

When the color object to be toned is a large object such as a car body, it is placed in various environments and it may be difficult to move indoors under relatively constant temperature conditions. Due to the large number, colorimetry is performed at various temperatures.

On the other hand, the paint blending database stored on the computer usually registers the colorimetric values measured in an indoor environment (room temperature).

Therefore, for the colorimetric value of a color object measured in an outdoor environment deviating from room temperature, finding the closest match on the basis of the colorimetric value registered in the database would significantly impair the matching accuracy. There is.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a paint for performing color matching between a selected target color object and a predetermined available paint color is provided. In the color matching method, (a) the target color object is analyzed, the target color data of the analyzed target color object is stored in a color measuring device, the surface temperature of the color object is measured, and the temperature is measured. Store the data in the temperature measuring device,
(B) sending the target color data stored in the color measuring device and the temperature data stored in the temperature measuring device to a computer, and (c) the target color data received by the computer and a plurality of available data. To obtain the most approximate sample color data by comparing it with the sample color data at the surface temperature of the coating film formed from the compounded paint according to various compounding data, and to obtain the optimum compounding data from the most approximate sample color data. There is provided a method for color matching of a paint, which comprises:

According to the present invention, in order to solve the above-mentioned problems, in a paint color matching device for performing color matching between a selected target color object and a predetermined available paint color, a) analyzing the target color object,
A color measuring device that stores the target color data of the analyzed target color object, and the surface temperature of the color object is measured,
A temperature measuring device for storing the temperature data; and (b) a computer for receiving the target color data stored in the color measuring device and the temperature data stored in the temperature measuring device, and (c) the computer. Compares the received target color data with the sample color data at the surface temperature of a coating film formed from a mixed paint according to a plurality of available combination data, and finds the closest sample color data. A paint color matching device is provided, which is provided with a means for obtaining optimum blending data from the most approximate sample color data.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will now be described with reference to FIG.

For example, the method of the present invention can be carried out using, for example, a system having the configuration shown in FIG.

This system comprises a three-angle spectrometer which constitutes the color measuring instrument 1, a server computer device, and an MO.
A terminal computer device 2 having a data display device that communicates via a DEM to display compound data, and an electronic automatic measuring device that forms a compound paint by measuring a paint primary color according to the compound data, and each terminal computer. The data from the device 2 is stored in the toning database, the closest approximation to the sample color data is searched, and the optimum mixture data is output. In this embodiment, the computer is composed of the terminal computer device 2 and the server computer device 3 which are separately arranged, but instead of this, it is also possible to configure them as an integrated device.

As a three-angle spectrocolorimeter, for example, a CM
512 m1 (manufactured by Minolta Camera Co., Ltd.) can be used. CM512m1 has a light-receiving angle of 45 °, and the illumination angle is 25 °, 45 °, 72.5 ° from the regular reflection angle of the received light.
By illuminating with 3 light sources respectively from the direction of, the spectral wavelength 400
It is a portable color measuring instrument capable of measuring the spectral reflectance in the range of nm to 700 nm with a wavelength interval of 20 nm. The color measuring instrument 1 can measure the spectral reflectance of the sample at three angles, and can also measure the surface temperature of the sample by a temperature measuring instrument incorporated integrally. Alternatively, the color measuring device and the temperature measuring device can be configured as separate devices.

As a matter of course, as the color measuring device 1, a one-angle spectrocolorimeter can be used instead of a three-angle spectrocolorimeter. When using a three-angle spectrophotometer,
Three kinds of target color data corresponding to three angles can be used for one color object, but when a one-angle spectrocolorimeter is used, one kind of target color data is used for one color object. The target color data will be used.

The CM 512m1 is used as the color measuring device 1 to measure, for example, the repair location of an automobile placed outdoors for repair. The measurement is performed, for example, five times in total while gradually changing the measurement site. After the measurement is completed, the color measuring device 1 is connected to the terminal computer device with a cable for data communication, and the measurement data (target color data) which is the spectral reflectance measurement value held and stored in the color measuring device 1 is transferred to the terminal computer device. Transfer to 2. Terminal computer device 2
Then, the five measurement data are stored, the average value thereof is calculated, and the color value L *, a is calculated from the spectral reflectance data under the three-angle condition.
Calculate * and b *. The color value L thus obtained
*, A *, b * (target color data) and temperature data are sent to the server computer device 3 to obtain the closest sample color data from the toning database stored and retained in the server computer device 3. Search for.

Instead of this, the color measuring instrument 1 calculates the average value of five measurement data, which are spectral reflectance data, and
Color value L *, a *, b from the spectral reflectance data of the angle condition
It is also possible to calculate * (target color data), store it, and send it to the terminal computer device.

Further, the color measuring device 1 may measure the target color data as the color values L *, a *, b *, store them, and send them to the terminal computer device.

In the color-matching database of the server / computer unit 3, data necessary for calculating the computer color-matching and, for example, about 3000 color-matching data are registered. The toning data is, for example, a combination plate that is a mixture ratio of the paint, and a coated plate that is created by coating the combination paint that is measured and mixed according to the combination data under standard conditions, for example,
Includes specific color data that is the color values L *, a *, b * of the three-angle condition obtained by measuring with the color measuring instrument 1 at a specific temperature in the range of 5 ° C. to 40 ° C. at 5 ° C. intervals. .

First, the server computer device 3
Based on the temperature data of the surface temperature of the sample, 5 ° C and 1 of each toning composition data stored in the toning database
After referring to the color values L *, a *, and b * at 0 ° C., the surface temperature (for example, 7.
Estimate and calculate the colorimetric value at 2 ° C.

L * = L * (5 ° C.) + (L * (10 ° C.) −
(L * (5 ° C.)) × (7.2-5) / (10−5) a * = a * (5 ° C.) + (A * (10 ° C.) − (A * (5
C)) x (7.2-5) / (10-5) b * = b * (5C) + (b * (10C)-(b * (5
C)) × (7.2-5) / (10-5) The three-angle color values L *, a *, b * of the sample (that is, three target color data) and the above-described method of the toning database. The difference ΔE from the sample color data at three angles, which is the estimated colorimetric value at 7.2 ° C. obtained by the above calculation, is calculated. The total value of the differences ΔE between the three target color data and the respective sample color data is used as the evaluation value in the search, and this processing is performed on about 3000 registered data, and the sample color data with the smallest evaluation value is the closest sample. This is determined as color data, and optimum combination data corresponding to this closest sample color data is returned to the terminal computer device for display.

According to the displayed combination data, an electronic automatic weighing device integrated with the terminal computer device is used to display the combination data sent from the server computer device to the terminal computer device on the data display device. The paint is automatically weighed according to the compounding data to form a compounded paint. Alternatively, the paint is metered by a metering device separate from the terminal computer device to produce a compounded paint.

In this embodiment, the server computer device uses a plurality of available formulation data and a specific temperature of the coating film formed from each of the plurality of formulation paints according to the available formulation data (for example, the above-mentioned specific temperature). 8 temperatures every 5 ° C., 5-40 ° C., ie 5 ° C., 10
Store specific color data at a temperature of 15 ° C, 15 ° C, 20 ° C, ..., 40 ° C) and a calculation formula for deriving sample color data at a predetermined temperature (for example, 7.2 ° C) from the specific color data. There is. Then, the server computer device compares the target color data at the surface temperature with the sample color data at the surface temperature (for example, about 3000 kinds) derived by the above calculation formula, and approximates the sample color data. To find the optimum blending data from the most approximate sample color data. In this mode, since the sample color data corresponding to the combination data of about 3000 at eight specific temperatures is stored, the sample color data of about 24,000 is stored. Furthermore, when storing the sample color data of three angles at each specific temperature, about 7
2,000 sample color data will be stored.

As a second alternative to this, the server computer device uses a plurality of available formulation data and a specific temperature of a coating film formed from each of the plurality of formulation paints according to the available formulation data. Various temperatures calculated from specific color data in
341 temperature of every 0.1 ℃, that is, 5.0 ℃,
5.1 ° C, 5.2 ° C, 5.3 ° C ... 39.8 ° C, 3
The sample color data at 9.9 ° C. and 40.0 ° C.) may be stored. Then, the server computer device compares the target color data at the surface temperature with the stored sample color data at the surface temperature, finds the closest target color data, and obtains the closest sample color data. Optimal formulation data is obtained from. In this case,
Since the server / computer device stores the sample color data corresponding to about 3000 compound data at various temperatures at 341 locations, it stores about 1,023,000 sample color data. Furthermore, when the sample color data of three angles at each specific temperature is stored, about 3,069,000 sample color data is stored.

Furthermore, as a third aspect, the server computer device uses a plurality of available formulation data and a coating film formed from a plurality of formulation paints according to the available formulation data at various temperatures. The sample color data obtained by actual measurement may be stored. Also in this case, the server / computer device compares the target color data at the surface temperature with the stored sample color data at the stored surface temperature to find the closest sample color data, Optimal blending data is obtained from sample color data. In this case, as in the second aspect, the server computer device stores the sample color data.

Of course, the numerical values of the number of available compounding data (about 3000), the interval of specific temperature (5 ° C.), the interval of various temperatures (0.1 ° C.), etc. are given as an example. Various values can be used in consideration of required accuracy, economy, and the like.

It is also possible that the server computer device is configured to correct the optimum combination data according to the difference between the target color data received and the obtained closest color data. Further, the server computer device compares the received target color data with the color data obtained by actually measuring the coating film formed from the blended paint according to the obtained optimum blending data, and this comparison is made. Accordingly, the optimum formulation data can be modified according to the above.

[0029]

【Example】

(Embodiment 1) As shown in FIG. 1, a system equipped with a three-angle spectrocolorimeter CM512m1 constituting a color measuring instrument 1, a terminal computer device 2, and a server computer device 3 was used.

The CM 512m1 was used to measure the repair location of a vehicle placed outdoors for repair. The measurement was performed 5 times in total while changing the measurement site little by little.
After the measurement was completed, the CM 512m1 was connected to the terminal computer device with a cable for data communication, and the measurement data (target color data) retained and stored in the CM 512m1 was transferred to the terminal computer device. On the terminal computer, the average value of five measurement data was calculated, and the color values L *, a *, b * (target color data) were calculated from the spectral reflectance data under the three-angle condition. The measured surface temperature of the sample was 7.2 ° C.

These color values L *, a *, b * (target color data) and temperature data were sent to the server / computer device.

Using the toning data stored and retained in the server / computer device, the optimum blending data was searched as follows.

In the color-matching database of the server / computer device 3, data necessary for calculating the computer color-matching and about 3000 color-matching data are registered. The toning data is the blending ratio of the paint, which is the blending data, and the paint plate made by coating the paint that is measured and blended at the blending ratio under the standard conditions at 5 ° C to 40 ° C at 5 ° C intervals. Color value L of three angles obtained by measuring with CM512m1 at temperature
*, A *, b * (specific color data). That is, the toning database stores about 3000 combination data and three types of specific color data under the three-angle condition at each specific temperature of 5 ° C. of each combination data.

First, the server computer device 3
Based on the measured surface temperature of the sample (temperature data), refer to the color values L *, a *, b * (specific color data) at 5 ° C and 10 ° C of the compounding data held in the toning database. , The sample color data for each of the three angle conditions at 7.2 ° C. was estimated and calculated by the interpolation calculation process of the following formula.

L * = L * (5 °) + (L * (10 °)-
L * (5 °)) × (7.2-5 / (10-5) a * = a * (5 °) + (a * (10 °) -a * (5
°)) x (7.2-5 / (10-5) b * = b * (5 °) + (b * (10 °) -b * (5
)) X (7.2-5 / (10-5) target color data which are the color values L *, a *, b * of three angles of the sample and 7.2 ° C obtained using the above method. The difference ΔE with each sample color data in was calculated as the evaluation value in the search with the total value of the differences ΔE under the three angle conditions, and this processing was performed for about 3000 sample color data to obtain the minimum evaluation value combination. Recently, the sample color data was determined to be similar, and the corresponding combination data was returned to the terminal computer as the optimum combination data, where the difference ΔE in the three-angle condition was 0.5, 0.8, 0.6. The toning formulation was as follows.

Primary Color Paint Type Weight Ratio Maroon A 86.47 Orange A 7.52 Red A 3.76 Pearl Red A 1.50 Pearl Red B 0.75 According to the optimum compounding data displayed on the terminal computer device, the measurement compounding is performed. Then, a mixed paint was formed, and a coated plate coated with the mixed paint under standard conditions was brought into contact with an automobile to be repaired, and the spectral reflectance and the surface temperature were measured once with CM512m1. The surface temperature was 7.2 ° C. It is the target color data of the repaired part of the automobile, which is obtained by transferring the obtained spectral reflectances of three angles to the terminal computer device, calculating the color values L *, a *, and b *, and holding the terminal computer device. When the difference ΔE from the color values L *, a *, b * was calculated, values of 0.7, 0.7, 0.8 were obtained for the three angles. When the color of the repaired part of the automobile and the painted plate were visually inspected, good color matching was confirmed.

Example 2 The data obtained as in Example 1 was sent to a server computer device.

Using the toning data stored and retained in the server / computer device, the optimum blending data was searched as follows.

The data necessary for the computer toning calculation and about 3000 toning data are registered in the toning database of the server / computer device. The toning data is the blending ratio of the paint which is the blending data, and the painted plate made by coating the paint which is measured and blended at the blending ratio under the standard condition at 5 ℃ to 40 ℃ at 0.1 ℃ intervals. C
The target color data is the color values L *, a *, and b * under the three-angle condition obtained by actually measuring with M512m1. That is, the toning database stores about 3000 combination data and three kinds of sample color data at temperatures of 0.1 ° C. intervals of each combination data.

In the search for the optimum combination data on the server / computer device 3, the color values L * of the three angles of the sample,
Calculate the difference ΔE between the three types of target color data, a * and b *, and the sample color data at each angle of 7.2 ° C held on the toning database, and sum the difference ΔE of the three angles. The value was used as the evaluation value in the search. This processing was performed on about 3000 registered data, the sample color data having the smallest evaluation value was determined as the most approximate target color data, and the compound data corresponding to this target color data was returned to the terminal computer device. At this time, ΔE of the three angles is
It was 0.4, 0.7, 0.6. The optimum combination data selected from about 3000 combination data was the same as the optimum combination data obtained in Example 1.

According to the optimum compounding data displayed on the terminal computer device, the compounding compounding is performed to form the compounding compound, and the coated plate coated under the standard condition is brought into contact with the automobile to be repaired and the angle spectrum is measured with CM512m1. The reflectance and the surface temperature were measured once. Surface temperature is 7.2 ° C
was. The obtained three-angle spectral reflectance is transferred to the terminal computer, the color values L *, a *, and b * are calculated, and the color value L, which is the target color data of the repaired part of the automobile held in the terminal computer device, is stored. When the difference ΔE from *, a *, b * was calculated, 0.7, 0.6, 0.
A value of 8 was obtained. When the color of the repaired part of the automobile and the painted plate were visually inspected, good color matching was confirmed.

Comparative Example In the database on the server / computer device, the data necessary for the computer toning calculation and about 3000 toning compound data were registered. The toning data is the mixture ratio of the paint, which is the mixture data, and the coated plate created by coating the paint measured in the mixture ratio under standard conditions.
3 obtained by measuring with CM512m1 under the condition of 23 ° C
It is composed of color values L *, a *, b * (sample color data) of the angle condition.

In the search for the most approximate mixture data on the server / computer device, the color value L of the sample under the three-angle condition is used.
Color value L under the three-angle condition corresponding to each of the target color data of *, a *, and b * and the combination data on the database
The difference ΔE from the sample color data of *, a *, b * was calculated. Using the total value of the difference ΔE of the three angles as the evaluation value in the search, this processing is performed for about 3000 sample color data, and the combination with the minimum evaluation value is determined as the closest approximate sample color data. The corresponding formulation data was returned to the terminal computer device. At this time, the difference ΔE of the three angles was 0.4, 0.6, and 0.5, respectively. The optimum compounding data selected from about 3000 compounding data was different from the optimum compounding data of Examples 1 and 2. The compounding data was as follows.

Primary color paint type Weight ratio Red B 57.02 Red C 26.32 Maroon B 8.77 Black 5.70 Aluminum AB 1.32 Pearl Red C 0.87 According to the optimum compounding data displayed on the terminal computer, Weighed and mixed to form a mixed paint, and using this, a coated plate coated under standard conditions was brought into contact with the automobile to be repaired, and the spectral reflectance and temperature were measured once with CM512m1. The surface temperature was 7.2 ° C. The obtained spectral reflectances at three angles are transferred to a terminal computer device and the color value L
*, A *, b * are calculated, and the color value L, which is the colorimetric value of the repaired part of the automobile held in the terminal computer device
When the difference ΔE from *, a *, b * was calculated, the values of 1.8, 1.6 and 1.3 were obtained for the three angles. When the color of the repaired part of the car and the painted plate were visually checked,
No good color match was obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a system capable of implementing the method of the present invention.

[Explanation of symbols]

 1 color measuring device 2 terminal computer device 3 server computer device

Claims (11)

[Claims] 1. A paint color matching method for matching a selected target color object with a predetermined paint color that can be used, comprising: (a) analyzing the target color object, Store the target color data of the target color object in the color measuring instrument,
The surface temperature of the color object is measured, the temperature data is stored in a temperature measuring device, and (b) the target color data stored in the color measuring device and the temperature data stored in the temperature measuring device are stored in a computer. And (c) the computer compares the received target color data with sample color data at the surface temperature of a coating film formed from a blend paint according to a plurality of available blend data, A method for color matching paints, which comprises finding similar sample color data and obtaining optimum blending data from the closest sample color data. 2. The computer, the specific color data at a specific temperature of a coating film respectively formed from a plurality of combination paints according to the available combination data, the specific color A calculation formula for deriving sample color data at various temperatures from the data is stored, and the computer stores the target color data, the temperature data, the specific color data, and the surface temperature derived by the calculation formula. 2. The method according to claim 1, wherein the optimum color mixture data is obtained from the closest approximated sample color data by finding the closest approximated sample color data. 3. The computer calculates various data from a plurality of available formulation data and specific color data at a specific temperature of a coating film respectively formed from a plurality of formulation paints according to the available formulation data. Of the sample color data at the temperature, the computer compares the target color data with the stored sample color data at the surface temperature, finds the closest target color data, and The method according to claim 1, wherein optimum combination data is obtained from similar sample color data. 4. The computer is obtained by actually measuring at different temperatures a plurality of formulation data available and a coating formed from a plurality of formulation paints according to the available formulation data. The target color data and the stored sample color data at the surface temperature stored therein, finds the closest sample color data, and calculates the most approximate sample color data. The method according to claim 1, wherein the optimum combination data is obtained from the sample color data. 5. The portable measuring instrument in which the color measuring instrument and the temperature measuring instrument are integrated with each other.
How to match the color of the paint. 6. The color object is measured by the color measuring device,
The target color data measured under a plurality of measurement conditions having different illumination-light receiving angle conditions and stored in the color measuring device, the target color data measured under the plurality of measurement conditions, are sent to the computer, and the computer receives them. And the target color data measured under the plurality of measurement conditions, and the sample temperature data under the plurality of measurement conditions at the surface temperature of the coating film formed from the combination paint according to the plurality of available combination data The paint color matching method according to claim 1, wherein the most approximate sample color data is found by comparing with, and optimum compounding data is obtained from the most approximate sample color data. 7. The color measuring device and the computer,
2. The paint color matching method according to claim 1, wherein the target color data is stored in the form of color values L *, a *, and b *. 8. The color measuring instrument measures a spectral reflectance measurement value in a visible range of a color object, and the color measuring instrument and the computer measure the spectral reflectance measurement value in a visible range of the color object. The computer stores the spectral reflectance measurement values of the measured visible range of the color object, which are stored in the color values L *, a *,
The method of color matching paint according to claim 1, wherein the color is converted into a b * form. 9. The paint according to claim 1, wherein the computer compares the received target color data with the obtained closest sample color data, and modifies the optimum blending data according to the result of the comparison. Color matching method. 10. The color matching method for a paint according to claim 1, wherein the obtained optimum blending data is displayed on a data display device of an electronic automatic weighing device. 11. A paint color matching device for performing color matching between a selected target color object and a predetermined available paint color, comprising: (a) analyzing the target color object and performing this analysis. A color measuring device that stores the target color data of the target color object,
And a temperature measuring device that measures the surface temperature of the color object and stores the temperature data, and (b) receives the target color data stored in the color measuring device and the temperature data stored in the temperature measuring device. (C) comparing the target color data received by the computer with sample color data at the surface temperature of a coating film formed from a blended paint according to a plurality of available blending data. Then, the paint color matching device is provided with means for finding the closest approximation sample color data and obtaining the optimum blending data from the closest approximation sample color data.