Method for color self-fitting of a semiconductor light emitter

Abstract

The application discloses a kind of semiconductor light emitting device color self-fitting method.The method is according to the principle of semiconductor white light mixing, through color quality diagram, the excitation light characteristics of fluorescent material are drawn, and the ratio of fluorescent material is determined in combination with display index.The method has simple structure, high fitting accuracy, can be directly connected or self-built database, pre-test input parameters, through mathematical fuzzy calculation technology, write in CIE color matching logical relationship, through the linear contrast of coordinate and the mode of experience data combination, automatically calculate and give the ratio meeting the requirements, realize the automatic ratio of fluorescent material.The method is more compatible with the increase of use times, effectively overcomes the problem that the spectrum and color of the matched fluorescent material cannot be completely fitted and synthesized according to the emission spectrum.

Description

TECHNICAL FIELD

[0001] The present application relates to a color self-fitting method, in particular to a color self-fitting method of a semiconductor light-emitting device, and belongs to the technical field of semiconductor preparation. BACKGROUND

[0002] The human eye is divided into cone cells and rod cells, which can perceive R, G and B three colors. In order to distinguish colors, different industrial systems have different color expression methods. For example, in the printing and dyeing industry, the CMYK color system is mainly used to facilitate the industrial standardization control of dyes; in the display screen industry, the RGB color system is used to facilitate the control of color gamut range and color brightness; in the field of active lighting, in order to more accurately express color and color brightness, there is a set of CIE colorimetry system to accurately define the infinite colors, which is widely used in the color definition of semiconductor light-emitting materials.

[0003] The CIE color system is a mixture of light of different wavelengths. The International Commission on Illumination (CIE) specifies that the wavelengths of red R, green G and blue B three primary colors are 700nm, 546.1nm and 435.8nm respectively, and when the relative brightness ratio of the three primary colors is 1:4.5907:0.0601, the white light can be matched (each is 1 / 3). CIE selects this ratio as the unit quantity of red, green and blue three primary colors, that is, (R):(G):(B)=1:1:1, wherein r=R / (R+G+B), g=G / (R+G+B), b=B / (R+G+B), r, g and b represent the proportion coefficient of each primary color: r+g+b=1.

[0004] The number of red, green and blue three primary colors corresponding to the equal-energy spectral color of each wavelength λ of the spectrum is called spectral tristimulus value r(λ), g(λ) and b(λ).

[0005] Now the domestic and foreign semiconductor light emitting device enterprises, especially the white light process, usually adopts the way of semiconductor chip plus fluorescent material to realize white light, and the debugging ratio adopts manual experimental ratio, according to the experience of engineers, different fluorescent powder is used to achieve the market required effect, the way and experience of each engineer is different, and the time and debugging times are also different, which leads to that the automatic link must depend on individual skills, the continuity of automatic production is poor, and the consistency of factory products has great difference. In order to solve this problem, various factories have experimented many schemes, but limited by the consistency of the supplied materials, such as the wavelength of the chip, the half wave width, the test error and label of each manufacturer, the consistency of the fluorescent material firing batch, and the specification of the bracket, so the problem of automation has not been solved. And the spectral energy diagram of the chip and fluorescent material of each manufacturer on the market has great difference, so the spectral and color matching cannot be completely fitted according to the emission spectrum. SUMMARY

[0006] In view of the problems in the prior art, the present application provides a semiconductor light emitting device color self-fitting method, which draws the excitation light characteristics of the fluorescent material according to the semiconductor white light mixing principle through the color chart, and determines the ratio of the fluorescent material in combination with the display index. The method has simple structure, high fitting accuracy, can be directly connected or self-built database, realizes automatic ratio of the fluorescent material, and effectively overcomes the problem that the spectral and color matching of the matched fluorescent material cannot be completely fitted according to the emission spectrum.

[0007] To achieve the above technical purpose, the present application provides a semiconductor light emitting device color self-fitting method, comprising the following steps:

[0008] 1) According to the emission energy spectrum of different fluorescent materials under excitation light irradiation, a scatter plot is drawn on the color chart;

[0009] 2) Determine the coordinates of the visible light of the semiconductor light emitting chip in the color chart, and take the coordinates as the starting point and connect the scatter plot, and calculate the Ki and Bi values of the connecting line;

[0010] 3) According to the execution standard ANSI C78.377-2015, a target point is selected near the blackbody locus Duv±0.015 of the color chart;

[0011] 4) According to the colorimetric system 1931 CIE algorithm and the color rendering index algorithm, the ratio of the fluorescent material is determined;

[0012] 5) Test the matched fluorescent material, and optimize the algorithm according to the test result.

[0013] The self-fitting method provided by the application adopts a five-step method to construct, and displays the unquantifiable color into a chromaticity diagram coordinate, through a limited number of fittings, the proportion of the fluorescent material can be determined, the target color can be accurately restored, and the proportion of the fluorescent material is automatically realized, so that the color difference caused by manual proportioning is effectively avoided.

[0014] As a preferred scheme, the excitation light is blue light and / or purple light; and the visible light wavelength range of the semiconductor light emitting chip is 400-470 nm.

[0015] As a preferred scheme, the CCT range of the target point on the black body locus is 2000-8000 K.

[0016] As a preferred scheme, the determination of the proportion of the fluorescent material includes the following processes:

[0017] i) determining the type of the fluorescent material according to the color rendering index, including the following three types:

[0018] When Ra=70, the fluorescent powder K1 and K3 closest to the slope K0 of the target point (X0, Y0) are selected, wherein one of K1 and K3 is greater than K0, and one is less than K0; when Ra=80, the fluorescent powder K1, K2, K3 and K4 closest to the slope K0 of the target (X0, Y0) are selected, wherein at least one is greater than K0, and at least one is less than K0; when Ra=90, the fluorescent powder K1, K2, K3 and K4 farthest from the slope K0 of the target (X0, Y0) are selected, wherein at least one is greater than K0, and at least one is less than K0; the slope K0 of the target point (X0, Y0) is the slope obtained by connecting the coordinates of the visible light of the semiconductor light emitting chip in the chromaticity diagram as the origin;

[0019] ii) mixing the determined fluorescent material at different proportions, and determining the K x value of the fluorescent material in the chromaticity diagram;

[0020] iii) the difference between K x and K0 is ΔK, and ΔK and the proportion of the fluorescent material are determined according to K x and the color rendering index of the target point.

[0021] As a preferred scheme, the relationship between K x and the proportion of the fluorescent material is Kx=n[a*(K1, K2)+b*(K3, K4)], wherein K1, K2>Kx, K3, K4<Kx; a and b are quality constants that cannot be zero, and 25≥a / b≥5; n is a powder glue ratio constant, which is adjusted according to uncontrollable factors of the bracket, and 1.2≥n≥0.05.

[0022] As a preferred scheme, the relationship between the color rendering index and the fluorescent material is: R(x, y) = aK1 + bK2 + cK3 + dK4; wherein, R(x, y) is the color rendering index required by the target coordinate point, a, b, c and d are quality constants which can be 0.

[0023] As a preferred scheme, the proportional relationship between the ΔK and the fluorescent material is: Wherein, ΔK is the slope change amount, and a / b is the mass ratio of the required fluorescent material.

[0024] As a preferred scheme, the algorithm optimization process is: test the color rendering index of the well-proportioned fluorescent material, denoted as Rx, when Rx > R(x, y), proportionally increase b and c; when Rx < R(x, y), proportionally increase a and b, and debug until Rx = R(x, y).

[0025] The scheme adopts pre-test entry parameters, mathematical fuzzy calculation technology, writes CIE color matching logical relationship, requires linear comparison of color coordinates and actual color coordinates and the combination of experience data, and automatically calculates and gives the required proportioning

[0026] Compared with the prior art, the beneficial effects of the present application are:

[0027] 1) The self-fitting method provided by the present application determines the proportioning of the fluorescent material according to the semiconductor white light mixing principle, by drawing the excitation light characteristics of the fluorescent material on the color quality diagram, and in combination with the display index. The method has a simple structure and high fitting accuracy, and effectively overcomes the problem that the light spectrum and color of the proportioned fluorescent material cannot be completely fitted and synthesized according to the emission spectrum.

[0028] 2) In the technical scheme provided by the present application, a database can be directly connected or self-built, pre-test entry parameters are adopted, mathematical fuzzy calculation technology is used, CIE color matching logical relationship is written, linear comparison of color coordinates and actual color coordinates and the combination of experience data are required, and automatic calculation is performed to give the required proportioning.

[0029] DRAWINGS

[0030] Figure 1 Positions of different fluorescent materials on the color quality diagram;

[0031] Figure 2 Position of the target point of the blackbody locus Duv±0.015 on the color quality diagram. DETAILED DESCRIPTION

[0032] The present application will be further described below in combination with the drawings and examples. The raw materials described in the present application are obtained through commercial channels. The preparation methods described in the present application are conventional preparation methods in the art unless otherwise specified. The following examples are intended to illustrate the present application but not to further limit the present application.

[0033] The present application provides a method for realizing automatic proportioning of semiconductor white light according to target requirements, and the specific implementation steps are as follows:

[0034] Step 1: According to the emission energy spectrum of the fluorescent material under the action of blue light or purple light and the coordinate point on the chromaticity diagram, as shown in Figure 1 .

[0035] Step 2: According to the coordinate points of different wavelength chips on the 1931 CIE chromaticity diagram as starting points, the coordinate points of the fluorescent material are connected, and the Ki and Bi values of these lines are calculated.

[0036] Step 3: Select several standard points on the blackbody locus (Table 2: reference standard ANSI C78.377-2015).

[0037] Step 4: According to the algorithm of 1931 CIE (x, y) system and the algorithm of color rendering index, combined with big data experience, select the relevant fluorescent powder matching principle. The matching principle is as follows:

[0038] Ra70: Select fluorescent powder K1, K2 closest to the slope K0 of the target (X0, Y0), wherein K1, K2 must have one greater than K0 and one less than K0. For example, K1>K0, K2<K0.

[0039] Ra80: Select fluorescent powder K1, K2, K3, K4 closest to the slope K0 of the target (X0, Y0), wherein one to two must be greater than K0 and one to two must be less than K0.

[0040] Ra90: Select fluorescent powder K1, K2, K3, K4 farthest from the slope K0 of the target (X0, Y0), wherein one to two must be greater than K0 and one to two must be less than K0.

[0041] Step 5: According to the K i values of different fluorescent powders, adjust the mixture K x according to different proportions, find the relationship between the change of K and the proportion of fluorescent powder. The specific experimental data are as follows:

[0042] Step 6: Refer to the target (X0, Y0) and the range of Ra (R min ~R max ) in step 3, respectively according to the principle in step 4, adjust the proportion close to the target according to different wavelengths, and record the content of each powder in the calculation of the proportion of the powder glue ratio, find the function relationship between the content of the powder and the change of color temperature ΔT.

[0043] Step 7: Considering the uncontrollable variables in actual application, set one of the uncontrollable variables: chip energy spectrum coordinates.

[0044] Step 8: Considering the uncontrollable variables in the actual application, set the second uncontrollable variable: the model of the bracket, and repeat Step 6 according to the model, and record and save it as a database.

[0045] Table 1 Coordinates of fluorescent materials on the color quality diagram and Ki and Bi values

[0046] 1# 2# 3# 4# 5# 6# 7# 8# X 0.341 0.361 0.383 0.441 0.625 0.631 0.648 0.660 Y 0.569 0.571 0.566 0.541 0.374 0.367 0.351 0.340 Ki 1.669 1.582 1.478 1.227 0.598 0.582 0.542 0.515 Bi -0.411 -0.372 -0.331 -0.247 -0.089 -0.086 -0.077 -0.071

[0047] Table 2 Coordinates of selected target points on the blackbody locus

[0048] CCT 2200K 2500K 2700K 3000K 3500K 4000K 4500K 5000K 5700K 6500K X 0.5018 0.481 0.458 0.434 0.4078 0.382 0.3613 0.345 0.3287 0.3123 Y 0.4153 0.414 0.410 0.403 0.393 0.380 0.367 0.355 0.3425 0.3283

[0049] Table 3 Coordinates of chip spectrum on the color spectrum

[0050] 440 445 450 455 460 465 470 475 X 0.1644 0.1611 0.1566 0.151 0.144 0.1355 0.1241 0.1096 Y 0.0109 0.0138 0.0177 0.0227 0.0297 0.0399 0.0578 0.0868

[0051] Example 1

[0052] Customer requirements: white light 6500K, Ra70, central coordinate point (0.3123, 0.3283)

[0053] Step 1: Select the 450nm blue chip coordinate (X1, Y1), confirm the coordinate point slope K0 = (0.3283-0.0177) / (0.3123-0.1566) = 1.9949

[0054] Step 2: Enter the fluorescent material parameters, select the powder Kn closest to the K0 slope, Kn = (Yn-Y1) / (Xn-X1), according to K n = n[a*(K1)+b*(K3)], K1, K2 > K0, K3, K4 < K0; take 25 > a / b > 5 middle number 15 for the first test;

[0055] Step 3: According to the first test data (Xi, Yi) technical Ki, and according to the slope change amount ΔK, adjust the value of a / b, give the ratio, and do the second test to confirm Ki = K0

[0056] Step 4: According to the adjusted slope ratio, test the value of Ri, when Ri < 70, Ri = aK1 + bK2 + cK3 + dK4; increase a and d in the same proportion, when Ri > 70, increase b and c in the same proportion.

[0057] Solve the equations involved in Steps 2, 3, and 4 by fitting, and after debugging, finally get a = 0.1, b = 0.75, c = 0.1, d = 0.05.

[0058] According to the obtained proportion, the fluorescent material is prepared, and test results show that the white light color temperature of the obtained mixed fluorescent material is 6500K, Ra is 70, there is no distortion and color difference, and the requirements are met.

[0059] Example 2

[0060] Customer demand: white light 5700K, Ra 80, central coordinate point (0.3287, 0.3425)

[0061] First step: select 450nm blue light chip coordinates (X1, Y1), and confirm the coordinate point slope K0 = (0.3425-0.0177) / (0.3287-0.1566) = 1.8873;

[0062] Second step: input the fluorescent material parameters, select the powder Kn closest to the slope K0, Kn = (Yn-Y1) / (Xn-X1), and adjust a / b according to K n = n[a*(K1,K2)+b*(K3,K4)], K1, K2 > K0, K3, K4 < K0; take the middle number 15 of 25≥a / b≥5 for the first test;

[0063] Third step: according to the test data (Xi, Yi) of the first test, adjust the value of a / b according to the slope change ΔK, give the proportion, and make the second test to confirm Ki = K0;

[0064] Fourth step: according to the proportion with adjusted slope, test the value of Ri, when Ri < 80, Ri = aK1+bK2+cK3+dK4; when Ri > 80, increase a and d in the same proportion, and when Ri > 80, increase b and c in the same proportion;

[0065] The equations involved in the second step, the third step and the fourth step are combined to fit, and finally a = 0.65, b = 0.2, c = 0.05, d = 0.1 are obtained after debugging;

[0066] According to the obtained proportion, the fluorescent material is prepared, and test results show that the white light color temperature of the obtained mixed fluorescent material is 5700K, Ra is 80, there is no distortion and color difference, and the requirements are met.

[0067] Example 3

[0068] Customer demand: white light 5700K, Ra 70, central coordinate point (0.3287, 0.3425)

[0069] First step: select 450nm blue light chip coordinates (X1, Y1), and confirm the coordinate point slope K0 = (0.3283-0.0177) / (0.3123-0.1566) = 1.8873;

[0070] Second step: input the parameters of fluorescent material, select the powder Kn closest to the slope of K0, Kn=(Yn-Y1) / (Xn-X1), according to K n = n[a*(K1)+b*(K3)], K1>K0, K3<K0; take 15 as the intermediate number of 25≥a / b≥5 for the first test;

[0071] Third step: according to the test data (Xi, Yi) of the first test, adjust the value of a / b according to the slope change of ΔK, give the ratio, and make the second test to confirm Ki=K0;

[0072] Fourth step: according to the adjusted slope ratio, test the value of Ri, when Ri<70, Ri=aK1+bK2+cK3+dK4, increase a and d in the same proportion; when Ri>80, increase b and c in the same proportion;

[0073] Combine the equations involved in the second step, the third step and the fourth step, and after debugging, finally get a=0.07, b=0.7, c=0.15, d=0.08;

[0074] According to the obtained ratio, the fluorescent material is adjusted, and after testing, the white light color temperature of the obtained mixed fluorescent material is 5700K, Ra is 70, there is no distortion and color difference, which meets the demand.

Claims

1. A method for color self-fitting of a semiconductor light emitter, characterized in that, It comprises the following steps: 1) scatter plot is drawn on the chromaticity diagram according to the emission energy spectrum of different fluorescent materials under excitation light irradiation; 2) the coordinates of the visible light of the semiconductor light emitting chip in the chromaticity diagram are determined, and the coordinates are taken as the starting point to connect the scatter plot, and the Ki and Bi values of the connecting line are calculated; 3) according to the execution standard ANSI C78.377-2015, the target point is selected near the blackbody locus Duv±0.015 in the chromaticity diagram; 4) according to the colorimetric system 1931CIE algorithm and the color rendering index algorithm, the ratio of the fluorescent material is determined; 5) the fluorescent material with the ratio is tested, and the algorithm is optimized according to the test result; The determination of the ratio of the fluorescent material comprises the following process: i) according to the color rendering index, the types of fluorescent materials are determined, including the following three types: When Ra=70, the fluorescent powder K1, K3 closest to the slope K0 of the target point (X0, Y0) is selected, wherein one of K1, K3 is greater than K0, and one is less than K0; When Ra=80, the fluorescent powder K1, K2, K3, K4 closest to the slope K0 of the target (X0, Y0) is selected, wherein at least one is greater than K0, and at least one is less than K0; When Ra=90, the fluorescent powder K1, K2, K3, K4 farthest from the slope K0 of the target (X0, Y0) is selected, wherein at least one is greater than K0, and at least one is less than K0; The slope K0 of the target point (X0, Y0) is the slope obtained by taking the coordinates of the visible light of the semiconductor light emitting chip in the chromaticity diagram as the origin; ii) The determined fluorescent materials are mixed in different proportions and their K value in the chromaticity diagram is determined x value; iii) K x The difference between K0 and Kx is denoted as ΔK, and the relationship between ΔK and the proportion of fluorescent material is determined according to the target point color rendering index. The K x The relationship between the fluorescent material ratio is: Kx=n[a*(K1, K2)+b*(K3, K4)], wherein, K1, K2>Kx, K3, K4<Kx; a and b are quality constants that cannot be taken 0, and 25>a / b>5; n is a powder glue ratio constant, which is adjusted according to uncontrollable factors of the support, 1.2>n>0.05; The relationship between the color rendering index and the fluorescent material is: R(x,y)=aK1+bK2+cK3+dK4; Wherein, R(x,y) is the color rendering index required by the target coordinate point, a, b, c and d are mass constants; The ΔK and the proportion relationship of the fluorescent material are as follows: ΔK=a / b ; wherein, ΔK is the slope change amount, and a / b is the mass ratio of the required fluorescent material.

2. The method of claim 1, wherein the method further comprises: determining a color of the light emitted by the semiconductor light emitting device; and adjusting the color of the light emitted by the semiconductor light emitting device. The excitation light is blue light and / or purple light; The wavelength range of the visible light of the semiconductor light emitting chip is 400~470nm.

3. The method of claim 1, wherein the method further comprises: determining a color of the light emitted by the semiconductor light emitting device; and adjusting the current supplied to the semiconductor light emitting device based on the determined color of the light emitted by the semiconductor light emitting device. The CCT range of the target point on the blackbody locus is 2000~8000K.

4. The method of claim 1, wherein the method further comprises: determining a color of the light emitted by the semiconductor light emitting device; and adjusting the current supplied to the semiconductor light emitting device based on the determined color of the light emitted by the semiconductor light emitting device. The algorithm optimization process is: the color rendering index of the fluorescent material with the ratio is tested, which is recorded as Rx, when Rx>R(x,y), b and c are increased in equal proportion; When Rx <R(x,y), a and b are increased in equal proportion, and the debugging is adjusted until Rx=R(x,y).

Images