TWI479134B - Two - dimensional timing type colorimeter detection method and the colorimeter - Google Patents

Description

Two-dimensional time series colorimeter detection method and the colorimeter

The invention relates to a two-dimensional time-series colorimeter detecting method and the colorimeter, in particular to a colorimeter capable of accurately quantifying the surface color of an object.

The human eye's perception of the color of the object is the diffused light reflected from the surface of the object after the visible light is irradiated onto the surface of the object, stimulating the activation of the cone responsible for color sensitization, and converting the light stimulus into a signal signal to the visual field of the brain. Discriminate, thereby producing color perception and discriminating the color of the object. Although the wavelength range of visible light varies from person to person, it generally covers about 400 to 750 nm.

Since the process of human perception of color is related to the light source, the surface of the object to be illuminated, and the color perception of the observer, it is not determined solely by the object. Therefore, when quantifying the color of the objective object, even if it is difficult to control the observer change Therefore, it is still necessary to consider the impact of the light source. In order to eliminate the interference factors of light source differences and unify the definition of color, the International Commission on Illumination (CIE) defines several standard illuminants and standard light sources, and in 1931, a chromaticity diagram was developed to reflect light through objects. With the color matching function developed by CIE, different weights are considered for different wavelengths, and finally the degree of brilliance is calculated, so any color can be marked with chromaticity coordinates on the chromaticity diagram.

In practice, the color measuring instruments can be mainly divided into a colorimeter and a spectrometer, and the CIE standard light source D is used as a light source. The former is to add a filter conforming to the CIE color matching function in front of the photosensitive element, and the reflected light of the object to be tested is filtered through the color matching function. From the light sheet to the photosensitive element, the corresponding chromaticity coordinates can be obtained through the calculation of the circuit; the latter uses the principle of light dispersion to arrange a plurality of photosensitive elements behind the dispersed light, the number of which varies according to the resolution, and then the measurement is excellent. The spectral distribution of light in the visible range, and then calculate the chromaticity coordinates via the CIE color matching function on the circuit.

Among them, the color matching function filter of the colorimeter on the market is difficult to plate in practice. Compared with the CIE standard light source D, the light source provided by the colorimeter does not fully comply with the standard, resulting in errors in the measured chromaticity values, and the colorimeter still has room for improvement and improvement.

For example, Taiwan Invention Patent No. I291549 "Color Temperature Adjustable Method of Colorimeter" refers to a method for simulating the CIE standard light source by adjusting the color temperature of the light source in the colorimeter. The main core method is to first calculate through the formula. After calculating the required spectral intensity of the light source, the color matching function, the reflectance of the object, and the wavelength frequency response of the optical power meter, according to the calculated result, the light source that meets the above calculated spectral distribution is arbitrarily combined using 24 LEDs, but In practice, the spectral distribution of such combined light sources is complex and cannot be achieved by simple linear superposition. For example, in D65+X light source, it is difficult to completely match near 500nm. These poorly matched areas are sources of measurement error. This is not the ideal solution.

Therefore, how to design the accuracy measurement accuracy and use multiple different central spectrum LEDs to illuminate, and without the complicated combination and strict screening, the light source can fully comply with the definition of CIE standard illuminant, more importantly Yes, when measuring the surface color of a large-area object, the spatial error can be effectively eliminated, and the measurement is more accurate. The above points will be an important issue in the manufacture of the colorimeter.

An object of the present invention is to provide a two-dimensional time-series colorimeter detection method and a colorimeter with high color measurement accuracy.

Another object of the present invention is to provide a two-dimensional time-series colorimeter detection method and a colorimeter that can combine a plurality of LEDs into a light source without complicated calculation.

It is still another object of the present invention to provide a two-dimensional time-series colorimeter detection method and colorimeter that conform to the CIE standard light source specification.

Still another object of the present invention is to provide a two-dimensional time-series colorimeter detection method and a colorimeter that can measure the surface color of a large-area object to be tested while eliminating spatial errors.

A two-dimensional time-series colorimeter detection method for analyzing a color of at least one surface of a test object and converting it into chromaticity, wherein the colorimeter has a surface for illuminating the object to be tested a composite light source, an image capturing device, a control and calculation output device, and a storage device; and wherein the composite light source comprises a plurality of LEDs having central wavelengths in the visible light range and different from each other at a central wavelength, and the surface of the object to be tested is Set in one pre Determining a region to be tested, the region to be tested is divided into a plurality of locations to be tested, and the storage device stores a reflection of each of the LEDs of each of the locations to be tested and a response of the image capturing device to each of the center wavelengths The overall compensation data includes the following steps: a) illuminating each of the LEDs of the synthetic light source one by one to illuminate the surface of the object to be tested in a timed manner; b) receiving the above by the image capturing device according to the position to be tested Each LED illuminates the reflected light on the surface of the object to be tested, and outputs a reflected data; and c) the above-mentioned control and calculation output device pairs all of the reflected light according to each of the above-mentioned measured positions for each illuminated LED The reflection data and the above overall compensation data are subjected to compensation operations, and a corresponding chromaticity data is output.

And a two-dimensional time-series colorimeter for analyzing the color of at least one surface of the object to be tested and converting it into chromaticity, the colorimeter having a predetermined area to be tested for setting the surface of the object to be tested, and the The measurement area includes a plurality of positions to be tested, the colorimeter includes: a composite light source for illuminating the surface of the object to be tested, and includes a plurality of LEDs whose center wavelengths are in the visible light range and different from each other at a center wavelength; and an instruction for the LED timing a control and calculation output device for illuminating the area to be tested one by one; an image capturing device for receiving the reflected light of the LEDs at each of the positions to be tested on the surface of the object to be tested, and outputting to the control and calculation output device; and storing The device stores, for each of the above-mentioned positions to be tested, the overall compensation data of the reflection of each of the LEDs and the response of the image capturing device to each of the central wavelengths, and the reflection of the control and the calculation output device according to the output of the image capturing device The data and the above-mentioned overall compensation data are subjected to compensation operations, and a corresponding chromaticity data is output.

The compensation operation is the key technology of this case, and the compensation content can be divided into Compensation, and compensation for the composite light source, the position compensation is performed by correcting the colorimeter before measuring the object to be tested, and setting a standard whiteboard in the area to be tested, wherein the area to be tested can be further divided into multiple to-be-tested areas. Measuring position, lighting a plurality of LEDs one by one, and recording the reflection data of each LED corresponding to each position to be tested by the image capturing device, and calculating position compensation data for each LED to be uniformized for each LED. In order to solve the problem of the position of the light source or the object to be tested and the size of the surface of the object to be tested during the measurement, the error of the measurement result is caused by the difference in the distance when the image capturing device takes the reflection data.

As shown in FIG. 1 , the present invention first places a standard whiteboard in the area to be tested, and divides the area to be tested covered by the standard whiteboard into a matrix of, for example, 3×3, and uses, for example, a CCD component as an image capturing device, and then in the matrix. Each block position CCD will obtain a sense measurement and color value. On the one hand, the result of the image will vary in space with the placement of the LED, for example, where the position of the light source is brighter and the surrounding position is darker; on the other hand, each block of the matrix is also associated with the CCD. The relative spatial difference of the position causes the received reflection data to have an influence. If the correct sensing data is to be obtained, the corresponding compensation must be given for both of the above, so that all the block position measurement results in the matrix are the same brightness. With color.

Secondly, since the composite light source of the present invention is formed by combining a plurality of LEDs having different center wavelengths, when the image capturing device extracts the reflected data, the photosensitive elements in the image capturing device may have different responses to different wavelengths. Size, which causes measurement errors. In particular, the brightness and center wavelength of each LED itself will also have differences in illumination intensity, attenuation, and wavelength drift with operating temperature and aging. Therefore, before the actual measurement, each LED must be compensated according to its luminous intensity and wavelength, and obtain the wavelength compensation data. According to the specifications of the CIE standard light source, as a compensation basis, for example, the CIE standard light source D65 can be simulated through multiple LEDs. Luminous intensity and spectral distribution.

In summary, the position compensation data and the wavelength compensation data are obtained by prior correction, and the two compensation materials are integrated into the overall compensation data, and the overall compensation data is recorded in the storage device, and the image capturing device is used as the actual measurement. After the reflection data is obtained, the control and calculation output device performs the basis of the compensation data, for example, on the surface of the object to be tested divided into nine squares, and is illuminated by a red LED, and when the image capturing device is taken to the position of the center of the nine squares The reflected light, control and calculation output device can pass the overall compensation data, the position of the center point, the red wavelength And the CIE color matching function performs the compensation operation, and then obtains a measurement result that does not cause an error due to the position of the object to be tested and the type of the light source, so that the correct chromaticity data can be obtained for each measurement.

Therefore, this case is suitable for measuring a large area of the object to be tested. At the same time, it is not necessary to perform a complicated combination of the light source LEDs to simulate a CIE standard light source. More importantly, the measurement result is not caused by the object to be tested, the light source or the image. The position of the device is changed to cause an error, and the above is the main point of the invention.

1‧‧‧Two-dimensional time series colorimeter

11‧‧‧Synthetic light source

111, 111 ₁ , 111 ₂ , 111 ₃ ‧‧‧LED

12‧‧‧Image capture device

13‧‧‧Control and calculation output device

14‧‧‧Storage device

15‧‧‧Predetermined area to be tested

151‧‧‧Location to be tested

152‧‧‧Matrix

2‧‧‧Standard Whiteboard

3'‧‧‧hemispherical reflector

4’‧‧‧Test objects

401-407‧‧‧Steps

501-504‧‧‧Steps

FIG. 1 is a schematic diagram showing the illumination distribution and the unevenness of the image brightness of a conventional colorimeter.

Figure 2 is a schematic view of a first preferred embodiment of the present invention.

Figure 3 is a block diagram showing the structure of the first preferred embodiment.

4 is a schematic diagram of a calibration compensation process of the present invention.

Figure 5 is a schematic diagram of the measurement process of the first preferred embodiment.

Figure 6 is a schematic view of a second embodiment of the present invention.

The above and other technical features, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

As shown in FIG. 2 and FIG. 3, in a first preferred embodiment of the present invention, a two-dimensional time-series colorimeter 1 includes: a composite light source 11, a control and calculation output device 13, an image capturing device 12, and a storage device. The device 14 is composed of, for example, 20 LEDs 111 whose central wavelengths are in the visible light range and whose center wavelengths are different from each other. The control and calculation output device 13 can instruct the above-mentioned LEDs 111 to be illuminated one by one. The imaging device 12 is illuminated. A charge coupled element (CCD) may be included, and a predetermined area to be tested 15 for setting the object to be tested, and the predetermined area to be tested 15 includes a plurality of positions 151 to be tested. As described above, the light source simulating any particular wavelength distribution, such as the standard light source D65 of the CIE, can be easily combined by the above-mentioned 20 LEDs 111 whose center wavelengths are different from each other and their input electric energy are respectively controlled.

Before the actual measurement, the present invention must have a pre-correction compensation step. Please refer to the flowchart of FIG. 4 together. In step 401, a standard whiteboard 2 is placed in the predetermined area to be tested 15, and the control and calculation output device 13 is provided. The command illuminates one of the LEDs 111 in the composite light source 11 Illuminating the standard whiteboard 2, the image capturing device 12 captures the reflected data corresponding to the LED 111 at each position 151 to be measured, and outputs the reflected data to the control and calculation output device 13, wherein the reflected data includes the reflected light intensity and the wavelength. Step 403 determines whether each of the LEDs 111 has been individually illuminated by the control and calculation output device 13. If not, then returning to step 401 to continue to illuminate the other LEDs 111 until each of the LEDs 111 is illuminated and the imaging device 12 is After the image capture has been completed, the control and calculation output device 13 calculates a position compensation data for each LED 111 to normalize the reflected light of each of the positions to be measured 151, and controls and calculates the output device 13 in accordance with step 405. The illuminating intensity of an LED 111 and the response of the image capturing device 12 to the center wavelength of each LED 111 are calculated as a wavelength compensation data for simulating the luminous intensity of each LED 111 by a predetermined luminous intensity component. In this embodiment, the CIE standard light source D65 is used. As a light source of the predetermined simulation, the following step 406 controls and calculates the output device 13 to integrate the position compensation data and the wavelength compensation data, and 151 corresponding to each position to be tested to obtain the entire information on each compensation LED111 reflection data, and finally transmitted to the storage device 14 stores at step 407 the overall compensation data.

In this example, 20 LEDs 111 are arranged in parallel as a planar direct-illuminated light source, and the luminous intensities of the LEDs 111 are substantially equal to each other, and the predetermined area to be tested 15 is divided into a plurality of positions to be tested 151, which in this example is divided into 9 positions to be tested 151.

During actual measurement, the object to be tested is placed on the matrix 152 of the predetermined area to be tested 15, and the flow of the steps is referred to FIG. 5. Step 501 is performed by the control and calculation output device 13 to illuminate an LED 111 of the planar direct-illuminated light source. The measuring object, step 502 receives the reflected light of the LED to the surface of the object to be tested according to each position 151 in the 3X3 matrix, and outputs a corresponding reflected data to the control and calculation output device 13, step 503 is controlled and The calculation output device 13 determines whether each of the LEDs 111 has been individually illuminated. If not, the step 501 continues to illuminate the other LEDs 111 until each of the LEDs 111 is illuminated and the image capture device 12 has completed the image capture. At step 504, the overall compensation data in the storage device 14 is extracted by the control and calculation output device 13, and the reflection data of the reflected light of all the LEDs 111 and the overall compensation data are compensated, wherein the compensation operation further includes an operation combined with the CIE color matching function. And outputting a chromaticity data of the surface of the object to be tested.

Therefore, setting the colorimetric timing does not need to consider the luminous intensity of each LED itself. As long as the back-end compensation operation is used, the illumination effect similar to the standard light source can be matched. The width reduces the threshold of the screening source; on the other hand, due to the spatial difference caused by the arrangement of the LEDs and the setting position of the image capturing device, it can also be easily eliminated by the compensation operation of the back end, so that the overall color detection accuracy and precision are both Can be greatly improved.

The planar direct-illuminated light source of the previous embodiment is the most common light source type at present, but may cause uneven distribution of light, and even if it can be compensated by the above compensation operation, there is still room for further improvement, and thus the present invention In a second embodiment, as shown in FIG. 6, the composite light source includes a hemispherical reflector 3' having a reflecting surface facing a predetermined area to be tested, and 20 different center wavelength LEDs 111 ₁ , 111 ₂ , and 111 ₃ are arranged in parallel. And the light emitting direction is disposed toward the hemispherical reflector 3', the image capturing device is disposed at the top opening of the hemispherical reflector 3', and the object to be tested 4' is disposed in the predetermined area to be tested, by the inner wall of the hemispherical reflector 3' The highly reflective, highly diffused material allows LEDs 111 ₁ , 111 ₂ , and 111 ₃ at different center wavelengths to achieve better light mixing for more uniform light illumination.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any simple equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the description of the invention should be It is still within the scope of the invention patent.

1‧‧‧Two-dimensional time series colorimeter

11‧‧‧Synthetic light source

12‧‧‧Image capture device

13‧‧‧Control and calculation output device

14‧‧‧Storage device

Claims (8)

A two-dimensional time-series colorimeter detection method for analyzing a color of at least one surface of a test object and converting it into chromaticity, wherein the colorimeter has a synthetic light source for illuminating the surface of the object to be tested, and a An image device, a control and calculation output device, and a storage device; and wherein the composite light source comprises a plurality of LEDs having central wavelengths in the visible light range and different from each other at a central wavelength, and the surface of the object to be tested is set to be predetermined to be tested a region, the predetermined area to be tested is divided into a plurality of positions to be tested, and the storage device stores a reflection of each of the LEDs and a response of the image capturing device to each of the center wavelengths Compensating data, the detecting method comprising the steps of: a) illuminating each of the LEDs of the synthetic light source one by one to illuminate the surface of the object to be tested in a timed manner; b) receiving, by the above-mentioned image capturing device, the LEDs according to the position to be tested Irradiating the reflected light to the surface of the object to be tested, and outputting a reflected data; and c) controlling all of the above reflections by the above control and calculation output device , Compensation calculation in accordance with each of the above-described position to be measured for each of the LED illumination reflection data and said overall compensation data, and outputs a corresponding chrominance data. The detection method according to claim 1, further comprising the following pre-processing steps before step a): d) setting a piece of standard whiteboard in the predetermined area to be tested, and lighting each of the LEDs one by one a standard whiteboard; e) recording the reflection data of each of the LEDs at each of the above-mentioned locations to be tested; f) calculating, for each of the LEDs, a position compensation data for homogenizing the reflected light of each of the locations to be tested; g) calculating a wavelength compensation data for simulating a predetermined luminous intensity component of the LED luminous intensity according to the luminous intensity of each of the LEDs and the response of the imaging device to each of the LED center wavelengths; and h) integrating calculation The position compensation data and the wavelength compensation data are obtained, and the overall compensation data for each of the LED reflective materials is obtained for each of the positions to be tested. The detecting method according to claim 2, wherein the predetermined luminous intensity component of the wavelength compensation data is calculated to be a component ratio of the CIE standard light source D65. A two-dimensional time-series colorimeter for analyzing the color of at least one surface of the object to be tested and converting it into chromaticity, the colorimeter having a predetermined area to be tested for setting the surface of the object to be tested, and the predetermined The measurement area includes a plurality of positions to be tested, the colorimeter includes: a composite light source for illuminating the surface of the object to be tested, and includes a plurality of LEDs whose center wavelengths are in the visible light range and different from each other at a center wavelength; and an instruction for the LED timing a control and calculation output device for illuminating the predetermined area to be tested one by one; an image capturing device for receiving the reflected light of the LEDs at each of the positions to be tested on the surface of the object to be tested, and outputting to the control and calculation output device; The storage device stores, for each of the above-mentioned positions to be tested, the overall compensation data of the reflection of each of the LEDs and the response of the image capturing device to each of the central wavelengths, and the output of the control and calculation output device according to the image capturing device The reflection data and the above overall compensation data are subjected to compensation operations, and a corresponding chromaticity data is output. The colorimeter according to claim 4, wherein the synthetic light source is a planar direct-illuminated light source in which the LEDs are arranged in parallel. The colorimeter according to claim 4, wherein the synthetic light source comprises a hemispherical reflector having a reflecting surface facing the predetermined area to be tested, and the LEDs are arranged in parallel and the light emitting direction is toward the hemispherical reflector. Settings. The colorimeter according to claim 4, 5 or 6, wherein each of the LEDs of the synthetic light source has the same luminous intensity. A colorimeter as described in claim 4, 5 or 6, wherein said image capturing means comprises a set of charge-coupled devices (CCDs).