CN110890057B - LED display screen color matching method based on chromaticity coordinate grading mixing - Google Patents

Abstract

The invention relates to a color matching method for an LED display screen based on graded mixing of chromaticity coordinates, which comprises the following steps: a display screen is formed by a plurality of types of tricolor light-emitting chips; drawing chromaticity coordinate points of all kinds of light-emitting chips in a CIE1931 chromaticity plane to form three coordinate stacks; drawing an inscribed triangle of the three coordinate stacks and taking the vertex coordinates of the inscribed triangle as a chromaticity coordinate target value of the three-primary-color matching; solving the tristimulus values of each primary color according to the brightness corrected by the three-primary-color light-emitting chip and calculating the target tristimulus values of the three primary colors according to the target value of the chromaticity coordinate; and obtaining a color matching coefficient matrix according to the target value of the chromaticity coordinates and the target tristimulus value, and multiplying the color matching coefficient matrix of each type by the correction coefficient of each light-emitting chip of the type, so that the color matching of the chromaticity coordinates graded light-emitting chips of different types of the display screen can be realized. The invention solves the technical problem of color deviation caused by mixed use of different types of light-emitting chips.

Description

LED display screen color matching method based on chromaticity coordinate grading mixing

Technical Field

The invention belongs to the technical field of LED display acquisition correction, and relates to a color matching method of an LED display screen.

Background

The LED chromaticity coordinate grading is a method for solving the problem of the dispersion of the self chromaticity of the LED. According to the method, the respective chromaticity coordinates of all the LED light-emitting chips are obtained according to the principle that each color corresponds to one chromaticity coordinate, and are classified, so that the LED light-emitting chips in the same class are ensured to have the same display color, and the problem of color deviation is avoided. Therefore, the LED light-emitting chips of the same type form a display screen, and the display screen has good color uniformity and good display quality.

However, in order to ensure that there is no chromaticity problem in the same category of light emitting chips, the classification range needs to be narrowed, the total number of classifications needs to be increased, and finally, there are dozens or even dozens of categories of light emitting chips of each color, which results in a relative reduction in the number of light emitting chips of each category. However, the number of light emitting pixels required by a high-density and large-size display screen is large, and the number of single light emitting chips cannot meet the number required by the display screen, so that two or more types of light emitting chips need to be mixed for application, so that chromaticity deviation is generated on the formed display screen, and the display effect is seriously influenced by the two or more types of different colors.

Disclosure of Invention

The invention aims to solve the technical problem of providing an LED display screen color matching method based on chromaticity coordinate grading mixing, which can solve the problem that the quantity of spliced display screens of chromaticity coordinate sorting light-emitting chips of the same category is not enough and solve the problem of color deviation of the display screens caused by mixed use of the light-emitting chips of different categories.

In order to solve the technical problem, the LED display screen color matching method based on the chromaticity coordinate graded mixing comprises the following steps:

step one, forming a display screen by using red, green and blue light-emitting chips subjected to chromaticity coordinate grading, and setting the type of the used red primary color light-emitting chip as k_r，k_r＝1,2,3...n_rThe green primary color light-emitting chip is k_g，k_g＝1,2,3...n_gThe kind of the blue primary color light emitting chip is k_b，k_b＝1,2,3...n_bWherein n is_r n_g，n_bThe total number of the categories of the three primary colors of red, green and blue respectively; let the chromaticity coordinate of each kind of red primary color light-emitting chip be (x)_ri，y_ri),i＝1,2,3...k_rThe chromaticity coordinate of each kind of the green primary color light emitting chip is (x)_gi，y_gi),i＝1,2,3...k_gThe chromaticity coordinate of each kind of the blue primary color light emitting chip is (x)_bi，y_bi),i＝1,2,3...k_b；

Drawing chromaticity coordinate points (x) of all kinds of red, green and blue three-primary-color light-emitting chips in a CIE1931 chromaticity plane_ri，y_ri),(x_gi，y_gi),(x_bi，y_bi) (ii) a Chromaticity coordinates (x) of all red primary colors_ri，y_ri) Form a red color coordinate stack, green primary color chromaticity coordinates (x)_gi，y_gi) Form a green color coordinate stack, and blue primary color chromaticity coordinates (x)_bi，y_bi) Forming a blue coordinate stack; finding and drawing an inscribed triangle of the three coordinate piles and determining three vertexes (x) of the triangle_rtarget，y_rtarget)，(x_gtarget，y_gtarget)，(x_btarget，y_btarget) (ii) a Wherein (x)_rtarget，y_rtarget) As a chromaticity coordinate target value for red base color matching, (x)_gtarget，y_gtarget) As a chromaticity coordinate target value for the color matching of the green primary color, (x)_btarget，y_btarget) As the target value of the chromaticity coordinate of the blue base color matching;

step three, performing brightness uniformity correction on all red, green and blue tricolor light-emitting chips on the display screen and recording the corrected red primary color brightness Y_rLuminance Y of the green primary color_gLuminance Y of blue primary color_b(ii) a Substituting all kinds of chromaticity coordinates of each primary color light-emitting chip into a formula (1) to obtain a tristimulus value of each kind of each primary color;

wherein X_ri，Y_ri，Z_riTristimulus value, X, of each kind of red primary color light-emitting chip_gi，Y_gi，Z_giTristimulus value, X, for each kind of green primary color red primary color light emitting chip_bi，Y_bi，Z_biThe tristimulus values of each kind of the blue primary color and the red primary color luminescent chip;

then the target value (x) of the chromaticity coordinate of the color matching of the three primary colors is calculated_rtarget，y_rtarget)、(x_gtarget，y_gtarget)、(x_btarget，y_btarget) Substituting into formula (2) to obtain respective target tristimulus values X of red, green and blue_rtarget，Y_rtarget，Z_rtarget，X_gtarget，Y_gtarget，Z_gtarget，X_btarget，Y_btarget，Z_btarget。

Y_rtarget＝Y_r

Y_gtarget＝Y_r

Y_btarget＝Y_r

Step four, mixing (X)_ri，Y_ri，Z_ri) As the first column, (X)_gi，Y_gi，Z_gi) As the second column, (X)_bi，Y_bi，Z_bi) Forming the original matrix H as a third column_oriWill be (X)_rtarget，Y_rtarget，Z_rtarget) As the first column, (X)_gtarget，Y_gtarget，Z_gtarget) As the second column, (X)_btarget，Y_btarget，Z_btarget) Forming an object matrix H as a third column_target：

Will be the original matrix H_oriAnd an object matrix H_targetSubstituting into formula (3), the color matching coefficient matrix A of each kind is obtained_i；

Step five, matching color coefficient matrix A of each kind_iAnd multiplying the correction coefficient of each luminous chip of the type to realize color matching of different types of chromaticity coordinate grading luminous chips of the display screen.

Because the target matrix is the same matrix, the color matching can ensure that the light-emitting chips with the same base color and the same type have no chromaticity problem and have no chromaticity problem among different types, thereby realizing the mixed use of the light-emitting chips with different types and different chromaticity coordinate grades and solving the problem of color deviation.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of the distribution of chromaticity coordinates of three primary colors on the CIE1931 chromaticity plane.

Fig. 2 is a schematic diagram of an inscribed triangle of a three-primary chromaticity coordinate stack.

FIG. 3 is a flow chart of the present invention.

Detailed Description

As shown in fig. 3, the color matching method for the LED display screen based on the graded mixing of chromaticity coordinates of the invention comprises the following steps:

step one, forming a display screen by using red, green and blue luminescent chips subjected to chromaticity coordinate grading, and recording the type k of the red primary color luminescent chip used for forming the display screen_r，k_r＝1,2,3...n_rThe type of the green primary color light-emitting chip is k_g，k_g＝1,2,3...n_gThe kind of the blue primary color light emitting chip is k_b，k_b＝1,2,3...n_b. Look over and record the chromaticity coordinate (x) of each kind of red primary color light-emitting chip_ri，y_ri)，i＝1,2,3...k_rChromaticity coordinate (x) of each kind of green primary color light emitting chip_gi，y_gi)，i＝1,2,3...k_gChromaticity coordinate (x) of each kind of blue primary light emitting chip_bi，y_bi)，i＝1,2,3...k_b。

Step two, all kinds of chromaticity coordinates (x) of the red primary color light-emitting chip_ri，y_ri) Chromaticity coordinates (x) of all kinds of green primary color light emitting chips_gi，y_gi) And chromaticity coordinates (x) of all kinds of blue primary color light emitting chips_bi，y_bi) And drawing the color coordinate of each primary color light-emitting chip of all kinds as a stack to form a color coordinate stack. Then, an inscribed triangle common to the three coordinate stacks is solved in the CIE color space, and three vertexes of the triangle are obtained. Recording three vertex chromaticity coordinates (x)_rtarget，y_rtarget)、(x_gtarget，y_gtarget)、(x_btarget，y_btarget) And is used as a chromaticity coordinate target value of the respective color matching of the three primary colors of red, green and blue.

And step three, lightening the display screen and correcting the brightness uniformity of the display screen. Then, brightness measurement is respectively carried out on the red primary color light-emitting chips of various types by utilizing a brightness meter to obtain brightness Y_rMeasuring the brightness of each green primary color light-emitting chip to obtain the brightness Y_gMeasuring the brightness of each blue primary color light-emitting chip to obtain the brightness Y_b. Respectively converting the chromaticity coordinate (x) of each kind of red primary color light-emitting chip_ri，y_ri) And a luminance Y_rChromaticity coordinate (x) of each kind of green primary color light emitting chip_gi，y_gi) And a luminance Y_gChromaticity coordinate (x) of each kind of blue primary color light emitting chip_bi，y_bi) And a luminance Y_bSubstituting into formula (1) to obtain tristimulus values of each kind of tricolor light-emitting chip.

X_ri，Y_ri，Z_riTristimulus value, X, for each kind of red primary color light emitting chip_gi，Y_gi，Z_giTristimulus value, X, for each kind of green primary light emitting chip_bi，Y_bi，Z_biRecording X for tristimulus value of each kind of blue primary color light-emitting chip_ri，Y_ri，Z_ri，X_gi，Y_gi，Z_gi，X_bi，Y_bi，Z_bi. Then the target value (x) of the chromaticity coordinate of the color matching of each of the three primary colors is calculated_rtarget，y_rtarget)、(x_gtarget，y_gtarget)、(x_btarget，y_btarget) Substituting into formula (2) to obtain respective target tristimulus values X of red, green and blue_rtarget，Y_rtarget，Z_rtarget，X_gtarget，Y_gtarget，Z_gtarget，X_btarget，Y_btarget，Z_btarget。

Y_rtarget＝Y_r

Y_gtarget＝Y_r

Y_btarget＝Y_r

Step four, the tristimulus value (X) of each kind of the red primary color light-emitting chip_ri，Y_ri，Z_ri) As a first column, the tristimulus value (X) of each kind of green primary light emitting chip_gi，Y_gi，Z_gi) As a second column, the tristimulus value (X) of each kind of blue primary light emitting chip_bi，Y_bi，Z_bi) As a third column, an original matrix H is constructed_oriTarget tristimulus values (X) of red and primary colors_rtarget，Y_rtarget，Z_rtarget) As a first column, the target tristimulus value (X) of the green primary color_gtarget，Y_gtarget，Z_gtarget) As a second column, the target tristimulus value (X) of the primary color blue_btarget，Y_btarget，Z_btarget) As a third column, an object matrix H is formed_targetAs shown in equation (3):

will be the original matrix H_oriAnd an object matrix H_targetSubstituting into the formula (4), the color matching coefficient matrix A of each kind is obtained_i。

Step five, matching color coefficient matrix A of each kind_iAnd multiplying the correction coefficient of each luminous chip of the type to realize color matching of different types of chromaticity coordinate grading luminous chips of the display screen.

The color matching method of the invention enables different types of luminous chips which are graded by chromaticity coordinates to be mixed together without color deviation, thereby not only ensuring that no chromaticity problem exists in single type graded by chromaticity coordinates, but also ensuring that different types of luminous chips are mixed, and enabling the chromaticity coordinate grading method to be applied to an oversized display screen.

Claims (1)

1. A color matching method for an LED display screen based on chromaticity coordinate grading mixing is characterized by comprising the following steps:

step one, forming a display screen by using red, green and blue light-emitting chips subjected to chromaticity coordinate grading, and setting the type of the used red primary color light-emitting chip as k_r，k_r＝1,2,3...n_rThe green primary color light-emitting chip is k_g，k_g＝1,2,3...n_gThe kind of the blue primary color light emitting chip is k_b，k_b＝1,2,3...n_bWherein n is_r n_g，n_bThe total number of the categories of the three primary colors of red, green and blue respectively; let the chromaticity coordinate of each kind of red primary color light-emitting chip be (x)_ri，y_ri),i＝1,2,3...k_rThe chromaticity coordinate of each kind of the green primary color light emitting chip is (x)_gi，y_gi),i＝1,2,3...k_gThe chromaticity coordinate of each kind of the blue primary color light emitting chip is (x)_bi，y_bi),i＝1,2,3...k_b；

Drawing chromaticity coordinate points (x) of all kinds of red, green and blue three-primary-color light-emitting chips in a CIE1931 chromaticity plane_ri，y_ri),(x_gi，y_gi),(x_bi，y_bi) (ii) a Chromaticity coordinates (x) of all red primary colors_ri，y_ri) Form a red color coordinate stack, green primary color chromaticity coordinates (x)_gi，y_gi) Form a green color coordinate stack, and blue primary color chromaticity coordinates (x)_bi，y_bi) Forming a blue coordinate stack; finding and drawing an inscribed triangle of the three coordinate piles and determining three vertexes (x) of the triangle_rtarget，y_rtarget)，(x_gtarget，y_gtarget)，(x_btarget，y_btarget) (ii) a Wherein (x)_rtarget，y_rtarget) As a chromaticity coordinate target value for red base color matching, (x)_gtarget，y_gtarget) As a chromaticity coordinate target value for the color matching of the green primary color, (x)_btarget，y_btarget) As the target value of the chromaticity coordinate of the blue base color matching;

step three, performing brightness uniformity correction on all red, green and blue tricolor light-emitting chips on the display screen and recording the corrected red primary color brightness Y_rLuminance Y of the green primary color_gLuminance Y of blue primary color_b(ii) a Substituting all kinds of chromaticity coordinates of each primary color light-emitting chip into a formula (1) to obtain a tristimulus value of each kind of each primary color;

wherein X_ri，Y_ri，Z_riTristimulus value, X, of each kind of red primary color light-emitting chip_gi，Y_gi，Z_giTristimulus value, X, for each kind of green primary color red primary color light emitting chip_bi，Y_bi，Z_biThe tristimulus values of each kind of the blue primary color and the red primary color luminescent chip;

then the target value (x) of the chromaticity coordinate of the color matching of the three primary colors is calculated_rtarget，y_rtarget)、(x_gtarget，y_gtarget)、(x_btarget，y_btarget) Substituting into formula (2) to obtain respective target tristimulus values X of red, green and blue_rtarget，Y_rtarget，Z_rtarget，X_gtarget，Y_gtarget，Z_gtarget，X_btarget，Y_btarget，Z_btarget；

Y_rtarget＝Y_r

Y_gtarget＝Y_r

Y_btarget＝Y_r

Step four, mixing (X)_ri，Y_ri，Z_ri) As the first column, (X)_gi，Y_gi，Z_gi) As the second column, (X)_bi，Y_bi，Z_bi) Forming the original matrix H as a third column_oriWill be (X)_rtarget，Y_rtarget，Z_rtarget) As the first column, (X)_gtarget，Y_gtarget，Z_gtarget) As the second column, (X)_btarget，Y_btarget，Z_btarget) Forming an object matrix H as a third column_target：

Will be the original matrix H_oriAnd an object matrix H_targetSubstituting into formula (3), the color matching coefficient matrix A of each kind is obtained_i；

Step five, matching color coefficient matrix A of each kind_iAnd multiplying the correction coefficient of each luminous chip of the type to realize color matching of different types of chromaticity coordinate grading luminous chips of the display screen.

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