Optical Measurement Method for Thickness or Mass of Each Monochromatic Material in a Scattering Color-Mixing Material with High Surface Reflectance

Abstract

The present invention discloses an optical measurement method for the thickness or mass of each monochromatic material in a scattering color mixing material with high surface reflectance, including Step 1 of obtaining the relationship between the light transmittance intensity and the light flux of each monochromatic material before color mixing, Step 2 of constructing a color mixing equation set for the relationship between the thickness or mass of each monochromatic material in the color mixing material and the total light flux of the color mixing material, and Step 3 of calculating the thickness or mass of each monochromatic material in the color mixing material at different concentrations. The involved optical model can regard the reflection of the material as internal scattering, reducing the effect of the material surface reflection on the color separation model, and realizing the calculation of the thickness or mass of each monochromatic material in a strongly scattering color mixing material at different concentrations when the surface reflection has a greater influence.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring methods for the thickness or mass of each monochromatic medium in a mixed-color medium, and particularly to the technical field of optical measuring methods for the thickness or mass of each monochromatic material in a strongly scattering mixed-color material with high surface reflectivity.

Background Art

[0002] The thickness and proportion at any position in a mixed-color material are related to the thickness and proportion of each monochromatic material at that position. People often use the transmission light measurement method to detect the thickness and proportion of each monochromatic material in a mixed-color material. This is because the composition of each monochromatic material in the mixed-color material is different, and certain changes occur after mixing, which will cause corresponding changes in optical properties.

[0003] In recent years, scientific researchers have applied color transmissive image information technology to the study of the internal structure and characteristics of materials. They mainly use the transmissive images obtained after transmission light passes through the object interior to reflect the internal characteristics of the object, and are involved in the detection in fields such as plant diseases and insect pests, and agricultural product quality. More specifically, for example, Zhang Wei et al. used hyperspectral transmission image technology to take the transmission images of eggs three days before hatching, and used the LVQ neural network model to construct a discrimination model for detecting the embryonic development of breeding eggs; Liu Yan et al. used a cold light source to irradiate eggs to obtain transmissive images, extracted the L component in the Lab space and the G component in the RGB space of the transmissive images, obtained three characteristics related to the freshness of eggs, namely the air chamber size, yolk size and ellipticity, and used the gradient descent method to train a freshness model of eggs with the three characteristic factors, which can be used for real-time freshness detection of eggs; Li Xiaoyu et al. proposed to use transmission machine vision imaging technology for rapid detection of internal defects of potatoes. By extracting the R component in the RGB space of the transmission image, the defect feature image was obtained through sample segmentation, and the PLS-SVM mode was used for recognition, and its inspection accuracy was high; Deng Limiao et al. studied the varieties of appearance traits of waxy corn during the growth period. Appearance characteristics related to the shape, texture, color, etc. of corn leaves were extracted from the transmission images and reflection images of corn leaves, and a BP neural network was established to analyze the recognition effects of various characteristics and the recognition effects of various color components. It was analyzed that the transmission image has a higher sample recognition rate than the reflection image.

[0004] However, the above research mainly uses the fact that when transmission light penetrates an object, changes in the internal or apparent characteristics of the object will be reflected in the transmission image, and then cooperates with the use of image segmentation methods to segment the region of interest, so as to identify the quality of the object as good or bad, and does not propose how to solve the problem of calculating the mass proportion or thickness of each component in the object.

[0005] To solve the problem of the thickness and proportion of each color material at any point in the mixed-color material, the applicant and the team have applied for the invention patent "Test Method for the Cumulative Thickness and Mass Proportion of Each Color Material at Any Point in the Mixed-Color Material" with the authorization announcement number CN107796315B. This method collects the transmission images of the mixed-color and single-color materials, applies the Lambert's law theory in the R, G, B three-dimensional color space, establishes a calculation method based on the transmission images, and verifies the applicability of this algorithm to polymer materials. However, when the thickness of the mixed-color material is relatively thick or the light scattering property of the material is relatively strong, the effect of this test method is not ideal.

[0006] To study strongly scattering materials, the applicant and the team have derived an algorithm for calculating the light scattering degree of strongly scattering materials based on the W-W model, and have also applied for the invention patent "Measurement Method for the Thickness or Mass of Monochromatic Materials at Any Point in a Mixed-Color Layered Material" with the application number 2021113346101. This measurement method can be applied to non-strong / strongly scattering materials and materials with relatively thick thickness, and the color separation effect is better than the color separation algorithm based on the original Lambert-Beer optical absorbance. It can be used for calculating the relative thickness or mass of each color-separated material in non-strong / strongly scattering materials such as single-mixed spinning ratio films and fiber materials of the same concentration. However, when using this measurement method to perform color separation calculations on different concentration materials with large surface reflection differences (such as 1-2, 1-1-2, and 1-2-1 in the following text), relatively large deviations will occur, which urgently need to be improved.

Summary of the Invention

[0007] The purpose of the present invention is to solve the problems in the prior art, and propose a measurement method for the thickness or mass of each monochromatic material in a differential mixed-color material. The optical model involved can regard the reflection of the material as internal scattering, reducing the effect of the material surface reflection on the color separation model, and realizing the calculation of the thickness or mass of each monochromatic material in strongly scattering mixed-color materials with different concentrations when the surface reflection has a greater impact.

[0008] To achieve the above object, the present invention proposes an optical measurement method for the thickness or mass of each monochromatic material in a scattering mixed-color material with high surface reflection, including the following steps:

[0009] Step 1: Obtain the relationship between the light transmission intensity and the light flux of each monochromatic material before mixing:

[0010] ① Test the light transmission intensity T iR 、T iG and T iB of the i-th monochromatic material (i = 1, 2, 3......) under the irradiation of red, green, and blue (R, G, B) monochromatic lights respectively;

[0011] ② Calculate the light flux I of the i-th monochromatic material (i = 1, 2, 3......) under the irradiation of red, green, and blue (R, G, B) monochromatic lights respectivelyiR 、I iG and I iB , where the luminous flux I iR 、I iG and I iB The calculation formulas are as follows respectively:

[0012] Under the irradiation of red monochromatic light,

[0013] Under the irradiation of green monochromatic light,

[0014] Under the irradiation of blue monochromatic light,

[0015] In formulas (1) to (3), r ∞,R 、r ∞,G and r ∞,B are respectively the reflectivities of the i-th material stacked to an infinite thickness under the irradiation of red, green, and blue (R, G, B) monochromatic lights, with the unit of %; R0, G0, and B0 are respectively the total luminous intensities of red, green, and blue (R, G, B) monochromatic lights;

[0016] Step 2: Construct a color mixing equation set that relates the thickness or mass of each monochromatic material in the color mixing material to the total luminous flux of the color mixing material:

[0017] ① According to the luminous fluxes I iR 、I iG and I iB obtained in Step 1, find the linear intervals (linear relationship ranges) between the thickness or mass of each monochromatic material and the luminous fluxes I iR 、I iG and I iB , and use the linear fitting method to find the linear equations between the thickness or mass of the i-th monochromatic material and the luminous fluxes I iR 、I iG and I iB : I i,m =S i,m x i +D i,R , which represents the luminous flux acting on the i-th material under the m-th monochromatic light (m = R, G, B), where represents taking the reflected light r ∞,i of the i-th material as the internal scattered light, and letting the following formula can be obtained:

[0018] I 1,R =D 1,R +S 1,R x1, I2,R = D 2,R + S 2,R x2,..., I i,R = D i,R + S i,R x i (4);

[0019] I 1,G = D 1,G + S 1,G x1, I 2,G = D 2,G + S 2,G x2,..., I i,G = D i,G + S i,G x i (5);

[0020] I 1,B = D 1,B + S 1,B x1, I 2,B = D 2,B + S 2,B x2,..., I i,B = D i,B + S i,B x i (6);

[0021] In formulas (4) to (6), x i is the thickness or mass of the i-th monochromatic material (i = 1, 2, 3......), with the unit of mm or mg, S i,m and D i,m are both constants of the linear fitting equation, s i is related to the astigmatic performance of the material itself, and D i,m is related to the noise;

[0022] ② Use I mix,m to represent the total luminous flux of the mixed-color material under the irradiation of the m-th monochromatic light (m = R, G, B). Construct the relationship equation between the total luminous flux of the mixed-color material and the thickness or mass of each monochromatic material therein by the following method, ensure that the thickness or mass of each monochromatic material is linearly related to the optical parameters of the corresponding channel, then convert it into matrix form, and use the least squares method to solve the thickness or mass of each monochromatic material:

[0023] A) When two materials are mixed, there is:

[0024] I mix,m = I 1,m + I 2,m (7);

[0025] Substitute formulas (4), (5) and (6) into equation (7) respectively, and then combine the three equations to form equation system (8);

[0026]

[0027] Convert formula (8) into matrix form AX=B, and then use the least squares method to solve X=(A T A) -1 A T B, thereby calculating the thickness or mass of each single color material in the mixed color material;

[0028] in, A is a 3×2 matrix, X is a 2×1 matrix, and B is a 3×1 matrix;

[0029] B) When multiple materials are mixed, there are:

[0030] I mix,m =I 1,m +I 2,m +…+I n,m (9);

[0031] Substitute formulas (4), (5) and (6) into equation (9), and then combine the three equations to form equation system (10);

[0032]

[0033] Convert formula (10) into matrix form AX=B, and then use the least squares method to solve X=(A T A) -1 A T B, thereby calculating the thickness or mass of each single color material in the mixed color material;

[0034] in, A is a 3×n matrix, X is an n×1 matrix, and B is a 3×1 matrix;

[0035] Step 3: Calculate the thickness or mass of each single color material in the mixed color material at different concentrations:

[0036] The light transmittance of the mixed color material under the irradiation of red, green and blue (R, G, B) monochromatic light is tested respectively, and the transmittance is substituted into formulas (1) to (3) in turn to obtain the optical calculated thickness of the mixed color material under the irradiation of each monochromatic light (R, G, B), and then substituted into formula (7) or (9) to solve the thickness or mass of each monochromatic material in the mixed color material.

[0037] Preferably, in step 1, the reflectivity r of the infinitely thick material is ∞ That is, the reflectivity of materials with a thickness of 0.5 to 3 cm.

[0038] Preferably, in the step 1, a layered sample formed by stacking fibers or polymer objects is irradiated with three uniform monochromatic lights of red, green, and blue (R, G, B), and at the same time, a digital color image of the transmitted light of the sample is obtained by using digital imaging technology.

[0039] Preferably, the three monochromatic lights of red, green, and blue (R, G, B) can also be replaced by monochromatic wave channels with different wavelengths.

[0040] Advantages of the present invention:

[0041] The present invention discloses a method for calculating the thickness or mass of each monochromatic material in a strongly scattering mixed material at different concentrations based on multi-channel spectral transmitted light flux. This invention is an improvement on the invention patent "Method for Measuring the Thickness or Mass of Monochromatic Materials at Any Point in a Mixed Layered Material" with the application number 2021113346101 in the process of acceptance by the applicant.

[0042] The present invention can be used to calculate the thickness or mass of each color-separated material in non-strong / strongly scattering materials at different concentrations, solving the problem in the previous invention that calculations can only be carried out at the same concentration: The present invention regards the reflection of the material as internal scattering, and based on the law of conservation of energy, it is derived from the sum of the reflected lights of each material being equal to the sum of the reflectivities of each color separation. This model reduces the effect of surface reflection of the material on the color separation model, and realizes the calculation of the thickness or mass of each monochromatic material in a strongly scattering mixed material at different concentrations when the surface reflection has a greater impact; however, the thickness range interval of the mixed material becomes smaller during measurement, and it is impossible to measure thicker materials; only by collecting the light transmission image information of the material, the thickness or mass of each monochromatic material in the mixed material can be accurately calculated; it provides a simple and rapid method for detecting the internal structure, performance, etc. of the mixed material.

[0043] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the drawings.

Description of the Drawings

[0044] Figures 1(a), 1(b), and 1(c) are respectively the relationships between the number of PET monochromatic film layers and the transmitted light intensity under the irradiation of three monochromatic lights of red, green, and blue (R, G, B).

[0045] Figures 2(a), 2(b), and 2(c) are respectively the relationships between the number of PET monochromatic film layers and the light flux I under the irradiation of three monochromatic lights of red, green, and blue (R, G, B).

[0046] Figures 3(a), 3(b), and 3(c) are respectively the relationships between the number of PET monochromatic film layers and the W-W model under the irradiation of three monochromatic lights of red, green, and blue (R, G, B).

[0047] Figures 4(a) and 4(b) show the comparison of the optically calculated thickness and the actual thickness of the yellow and blue mixed materials based on the present model and the W-W model, respectively;

[0048] Figures 5(a) and 5(b) show the comparison of the optically calculated thickness and the actual thickness of the blue and pink mixed materials based on the present model and the W-W model, respectively;

[0049] Figures 6(a) and 6(b) show the comparison of the optically calculated thickness and the actual thickness of the pink and cyan mixed materials based on the present model and the W-W model, respectively;

[0050] Figures 7(a) and 7(b) show the comparison of the optically calculated thickness and the actual thickness of the yellow, blue, and pink mixed materials based on the present model and the W-W model.

Detailed implementation manners

[0051] A uniform, transparent, and smooth-surface PET color film is used to verify the correctness of the present invention. The material information is shown in Table 1 below:

[0052] Table 1 PET color film information

[0053]

[0054] First, the light transmission intensities of each single-color film under the irradiation of three single-color lights of red, green, and blue (R, G, B) are tested and analyzed, and then the relationships between the light flux I, the W-W model, and the actual thickness (number of layers) are calculated according to formulas (1), (2), (3) and the W-W model. Among them, the W-W model formula is as follows:

[0055] Under the irradiation of red single-color light, Under the irradiation of green single-color light, Under the irradiation of blue single-color light,

[0056] In formulas (11) to (13), r ∞,R , r ∞,G and r ∞,B are the reflectivities of the i-th material stacked to an infinite thickness under the irradiation of three single-color lights of red, green, and blue (R, G, B), respectively, with the unit of %; R0, G0, and B0 are the total light intensities of the three single-color lights of red, green, and blue (R, G, B), respectively.

[0057] The results are shown in Figures 1(a), 1(b), 1(c), 2(a), 2(b), 2(c), 3(a), 3(b), and 3(c).

[0058] Example 1: Measurement and calculation of the thickness of each single-color material in the yellow and blue two-color PET mixed material:

[0059] In the linear intervals shown in Figures 2(a), 2(b), 2(c), 3(a), 3(b) and 3(c), the first 5 points are linearly fitted to obtain the linear fitting equations of the true thicknesses x1 and x2 of the two single-color films and the light fluxes I and W-W models under the irradiation of three single-color lights of red, green and blue (R, G, B). The results are shown in Table 2 below:

[0060] Table 2 Linear fitting equations between the single-color light fluxes I, W-W models and the true thicknesses of Materials 1# and 2#

[0061]

[0062] According to formula (7) and the relationship in the W-W model that the mixed light flux is equal to the sum of the single-color light fluxes, the total mixed light fluxes I mix and W-W model W mix under each single-color channel proposed in this patent are respectively constructed, and the relationship equations with the actual thicknesses of Materials 1# and 2# single-color materials are shown in formulas (14) and (15):

[0063] Light flux I:

[0064] W-W model:

[0065] Next, Materials 1# and 2# are stacked in three main forms: AB, BA and ABA, and the superimposed optical signals are all within the linear range. The specific stacking methods are 1-2, 1-1-2, 1-2-2, 1-1-2-2, 1-2-2-2, 1-1-1-2-2, 1-1-2-2-2; 2-1, 2-1-1, 2-2-1, 2-2-1-1, 2-2-2-1, 2-2-1-1-1, 2-2-2-1-1; 1-2-1, 2-1-2, 1-2-2-1, 2-1-1-2, 1-2-2-2-1, 2-1-1-1-2, 1-2-1-2-1, 2-1-2-1-2.

[0066] After measuring the corresponding light transmittance intensity and reflectance at infinite thickness of the sample respectively, substituting them into formulas (1), (2), (3), (11), (12) and (13), the optical calculated thicknesses I mix,R 、I mix,G 、I mix,B 、W mix,R 、W mix,G and W mix,B of the mixed-color film at different concentrations are calculated, and then substituting them into equations (14) and (15) respectively, and using the least squares method X=(A T A) -1 A TB. Calculate the optical calculated thickness of each monochromatic material in the color mixing material and compare it with the actual thickness. The results are shown in Figures 4(a) and 4(b).

[0067] As can be seen from Figures 4(a) and 4(b), the results of the optical calculated thickness of each monochromatic light calculated by the newly introduced luminous flux formula are close to the actual thickness. The maximum deviation rate is 10.5%, and the average deviation rate is 4.15% (the difference rate formula = (actual thickness - optical calculated thickness) / actual thickness); the results calculated by the W-W model deviate greatly from the actual results. The results prove the accuracy of the luminous flux calculation formula used in the present invention for calculating the thickness of each monochromatic material at any point in the color mixing material at different concentrations. Some measurement deviations are caused by the non-uniformity of the material thickness or quality.

[0068] Example 2. Measurement and calculation of the thickness of each monochromatic material in the blue and pink PET color mixing material:

[0069] In the linear intervals shown in Figures 2(a), 2(b), 2(c), 3(a), 3(b) and 3(c), perform linear fitting on the first 5 points to obtain the actual thicknesses x2 and x3 of the two monochromatic films and the linear fitting equations of the luminous flux I and the W-W model under the irradiation of three monochromatic lights of red, green and blue (R, G, B). The results are shown in Table 3 below:

[0070] Table 3 Linear fitting equations between the monochromatic luminous flux I, the W-W model and the actual thickness of materials 2# and 3#

[0071]

[0072] According to formula (7) and the relationship that the mixed luminous flux in the W-W model is equal to the sum of the monochromatic luminous fluxes, respectively construct the equations of the total mixed luminous flux I mix , the W-W model W mix and the actual thickness of materials 2# and 3# under each monochromatic channel proposed in this patent. See formulas (16) and (17):

[0073] Luminous flux I:

[0074] W-W model:

[0075] Superimpose materials 2# and 3# in three main forms: AB, BA, and ABA, and the superimposed optical signals are all within the linear range. The specific superimposing methods are 2-3, 2-2-3, 2-2-3-3, 2-2-2-3; 3-2, 3-2-2, 3-2-2-2, 3-3-2-2; 2-3-2, 3-2-3, 2-3-3-2, 3-2-2-3.

[0076] After respectively measuring the light transmittance intensity corresponding to the sample and the reflectance at infinite thickness, substituting them into formulas (1), (2), (3), (11), (12) and (13), the optical calculation thickness I of the color mixing film at different concentrations is calculated. mix,R 、I mix,G 、I mix,B 、W mix,R 、W mix,G and W mix,B values, then respectively substituting them into equations (16) and (17), and using the least squares method X = (A T A) -1 A T B, the optical calculation thickness of each single-color material in the color mixing material is calculated and compared with the true thickness. The results are shown in Figure 5(a) and Figure 5(b).

[0077] As can be seen from Figure 5(a) and Figure 5(b), the results of the optical calculation thickness of each monochromatic light calculated by the newly derived luminous flux formula are close to the true thickness. The maximum deviation rate is 15.63%, and the average deviation rate is 5.34% (the difference rate formula = (true thickness - optical calculation thickness) / true thickness)); the results calculated by the W-W model deviate greatly from the true results and are very discrete. The results prove the accuracy of the luminous flux calculation formula used in the present invention for calculating the thickness of each single-color material at any point of the color mixing material at different concentrations. Some measurement deviations are caused by the non-uniformity of the material thickness or quality.

[0078] Example 3: Measurement and calculation of the thickness of each single-color material in the strong diffused light PET color mixing material of pink and cyan:

[0079] Within the linear ranges shown in Figure 2(a), Figure 2(b), Figure 2(c), Figure 3(a), Figure 3(b) and Figure 3(c), the first 5 points are linearly fitted to obtain the true thicknesses x3 and x4 of the two single-color films and the linear fitting equations of the luminous flux I and the W-W model under the irradiation of three monochromatic lights of red, green and blue (R, G, B); as can be seen from Figure 2(c) and Figure 3(c), for the cyan film under the irradiation of blue-channel light, the first 5 points do not have a linear relationship with the actual values. In order to ensure that the selected intervals are all within the linear range, the first 3 points are selected for linear fitting. The results are shown in Table 4 below:

[0080] Table 4 Linear fitting equations between the luminous flux I, absorbance A of each monochromatic light and the true thickness of materials 3# and 4#

[0081]

[0082]

[0083] According to Equation (7) and the relationship in the W-W model that the mixed-color luminous flux is equal to the sum of the monochromatic luminous fluxes, the total mixed-color luminous flux I under each monochromatic channel proposed in this patent is constructed respectively. mix and the relationship equations of the W-W model W mix with the actual thicknesses of the No. 3 and No. 4 monochromatic materials are shown in Equations (18) and (19):

[0084] Luminous flux I:

[0085] W-W model:

[0086] Next, the No. 3 and No. 4 materials are stacked in three main forms: AB, BA, and ABA, and the superimposed optical signals are all within the linear range. The specific stacking methods are 3-4, 3-3-4, 3-4-4, 3-3-3-4, 3-3-4-4, 3-4-4-4; 4-3, 4-3-3, 4-4-3, 4-4-4-3, 4-4-3-3, 4-3-3-3; 3-4-3, 4-3-4, 3-4-4-3, 4-3-3-4, 4-3-3-3.

[0087] After measuring the corresponding light transmittance intensity of the sample and the reflectivity at infinite thickness respectively, substituting them into Equations (1), (2), (3), (11), (12), and (13), the optical calculation thicknesses I mix,R 、I mix,G 、I mix,B 、W mix,R 、W mix,G and W mix,B of the mixed-color film at different concentrations are calculated. Then, substituting them into the system of equations (18) and (19) respectively, and using the least squares method X = (A T A) -1 A T B, the optical calculation thicknesses of each monochromatic material in the mixed-color material are calculated and compared with the true thickness. The results are shown in Figures 6(a) and 6(b).

[0088] As can be seen from Figures 6(a) and 6(b), the results of the optical calculation thicknesses of each monochromatic light calculated by the newly proposed luminous flux formula are close to the true thickness, with a maximum deviation rate of 14.73% and an average deviation rate of 7.21% (the difference rate formula = (true thickness - optical calculation thickness) / true thickness)); the results calculated by the W-W model deviate greatly from the true results and are very discrete. The results prove the accuracy of the luminous flux calculation formula used in this invention for calculating the thicknesses of each monochromatic material at any point in the mixed-color material at different concentrations. Some measurement deviations are caused by the non-uniformity of the material thickness or quality.

[0089] Example 4: Measurement and calculation of the thickness of each single-color material in the yellow, blue, and pink PET mixed-color materials:

[0090] In the linear intervals shown in Figures 2(a), 2(b), 2(c), 3(a), 3(b), and 3(c), the first 5 points are linearly fitted to obtain the linear fitting equations of the true thicknesses x1, x2, and x3 of the two single-color films and the light fluxes I and the W-W model under the irradiation of three single-color lights of red, green, and blue (R, G, B). The results are shown in Tables 2 and 3 above:

[0091] According to formula (9) and the relationship that the mixed-color light flux in the W-W model is equal to the sum of the single-color light fluxes, the total mixed-color light fluxes I mix and the W-W model W mix in each single-color channel proposed in this patent are respectively constructed, and the relationship equation sets with the actual thicknesses of the 1#, 2#, and 3# single-color materials are shown in formulas (20) and (21): Light flux I: W-W model:

[0092] Next, the three materials of 1#, 2#, and 3# are stacked in the forms of 1-2-3, 1-3-2, 2-3-1, 1-2-1-3, and 2-3-1-3.

[0093] After respectively measuring the light transmittance intensity of the sample and the reflectance at infinite thickness and substituting them into formulas (1), (2), (3), (11), (12), and (13), the optical calculation thicknesses I mix,R 、I mix,G 、I mix,B 、W mix,R 、W mix,G and W mix,B of the mixed-color films at different concentrations are calculated. Then, they are respectively substituted into the equation sets (20) and (21), and the least squares method X = (A T A) -1 A T B is used to calculate the optical calculation thicknesses of each single-color material in the mixed-color material and compare them with the true thicknesses. The results are shown in Figures 7(a) and 7(b).

[0094] As can be seen from FIGS. 7(a) and 7(b), the results of the optical calculation thickness of each monochromatic light calculated by the newly introduced luminous flux formula are close to the true thickness, with a maximum deviation rate of 11.7% and an average deviation rate of 5.51% (the difference rate formula = (true thickness - optical calculation thickness) / true thickness)); the results calculated by the W-W model have a large deviation from the true results and are very discrete. The results prove the accuracy of the luminous flux calculation formula used in the present invention for calculating the thickness of each monochromatic material at any point of the color mixing material at different concentrations. Some measurement deviations are caused by the non-uniformity of the material thickness or quality.

[0095] The above embodiments are illustrative of the present invention and not restrictive thereof. Any simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. An optical measurement method for the thickness or mass of each monochromatic material in a scattering color mixing material with high surface reflectivity, characterized in that: The steps include: Step 1: Obtain the relationship between the light transmittance and luminous flux of each single-color material before color mixing: ①Test the light transmittance intensities $T_{ iR}$, $T_{ iG}$, and $T_{ iB}$ of the $i$-th monochromatic material under the illumination of red, green, and blue monochromatic lights respectively; iR 、$T_{ iR}$ iG and $T_{ iG}$ iB ; ② Calculate the luminous fluxes I iR , I iG , and I iB of the i-th monochromatic material under the illumination of red, green, and blue monochromatic transmitted lights respectively, where the calculation formulas for the luminous fluxes I iR , I iG , and I iB are as follows respectively: In formulas (1) to (3), r ∞,R , r ∞,G and r ∞,B are respectively the reflectance when the i-th material is stacked to an infinite thickness under the irradiation of red, green, and blue monochromatic lights, with the unit of %; R0, G0, and B0 are respectively the total light intensities of red, green, and blue monochromatic lights; Step 2: Construct a color mixing equation group of the relationship between the thickness or mass of each single color material in the color mixing material and the total reflected light flux of the color mixing material: ①According to the luminous flux I obtained in step 1 iR , I iG and I iB , find the linear intervals of the thickness or mass of each monochromatic material with respect to the luminous fluxes I iR , I iG and I iB respectively, and use the linear fitting method to obtain the linear equations of the thickness or mass of the i-th monochromatic material with respect to the luminous fluxes I iR , I iG and I iB respectively. At the same time, express it with the formula I i,m =S i,m x i +D i,R , which represents the luminous flux acting on the i-th material by the m-th monochromatic light, where represents regarding the reflected light r ∞,i of the i-th material as internal scattered light to reduce the effect of the reflected light on the dichroic model. Let , the following formula can be obtained: I 1,R = D 1,R + S 1,R x1, I 2,R = D 2,R + S 2,R x2,..., I i,R = D i,R + S i,R x i (4); I 1,G = D 1,G + S 1,G x1, I 2,G = D 2,G + S 2,G x2,..., I i,G = D i,G + S i,G x i (5); I 1,B = D 1,B + S 1,B x1, I 2,B = D 2,B + S 2,B x2,..., I i,B = D i,B + S i,B x i (6); In formulas (4) to (6), x i is the thickness or mass of the i-th monochromatic material, with the unit of mm or mg, S i,m and D i,m are both constants of the linear fitting equation, s i is related to the astigmatic performance of the material itself, and D i,m is related to noise; ②Let I mix,m represent the total luminous flux of the color mixing material under the irradiation of the m-th monochromatic light. The relationship equation between the total luminous flux of the color mixing material and the thickness or mass of each monochromatic material therein is constructed by the following method, and it is ensured that the thickness or mass of each monochromatic material has a linear relationship with the optical parameters of the corresponding channel. Then it is converted into matrix form, and the least square method is used to solve the thickness or mass of each monochromatic material: A) When two materials are mixed, there are: I mix,m = I 1,m + I 2,m (7); Substitute formulas (4), (5) and (6) into equation (7) respectively, and then combine the three equations to form equation system (8); Convert formula (8) into matrix form AX = B, and then use the least squares method to solve for X = (A T A) -1 A T B; where, B) When multiple materials are mixed, there are: I mix,m = I 1,m + I 2,m + … + I n,m (9); Substitute formulas (4), (5) and (6) into equation (9), and then combine the three equations to form equation system (10); Convert formula (10) into matrix form AX = B, and then use the least squares method to solve for X = (A T A) -1 A T B; where, Step 3: Calculate the thickness or mass of each single color material in the mixed color material at different concentrations: Test the transmittance of the mixed color material under red, green and blue monochromatic light, and substitute them into formulas (1) to (3) in turn, and then substitute them into formula (7) or (9) to solve for the thickness or mass of each monochromatic material in the mixed color material.

2. The optical measurement method for the thickness or mass of each monochromatic material in the scattering color mixing material with high surface reflectivity according to claim 1, characterized in that: In step 1, the reflectivity r of the material with infinite thickness ∞ That is, the reflectivity of the material with a thickness of 0.5 to 3 cm.

3. The optical measurement method for the thickness or mass of each monochromatic material in the scattering color mixing material with high surface reflectivity according to claim 1, characterized in that: In step 1, uniform red, green and blue monochromatic lights are used to illuminate the layered sample formed by stacking polymer objects, and digital imaging technology is used to obtain a digital color image of the transmitted light of the sample.

4. The optical measurement method for the thickness or mass of each monochromatic material in the scattering color mixing material with high surface reflectivity according to claim 1, characterized in that: The three monochromatic lights of red, green and blue can also be replaced by monochromatic wave channels of different wavelengths.

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