CN102074206A - Color correction method, color correction device and LED color correction system - Google Patents

Abstract

The invention discloses a color correction method, a color correction device and an LED color correction system. Wherein the color correction method includes: using three sets of preset drive signals to drive the three-primary-color LED array board to emit light; chromaticity value; use the collected three groups of chromaticity values to obtain three groups of theoretical brightness ratio values of the three primary color LEDs in the tri-primary color LED array board; use three groups of pre-set driving signals to obtain three groups of actual brightness ratio values of the three primary color LEDs; The color correction coefficient is obtained by three sets of theoretical brightness ratio values and three groups of actual brightness ratio values; the color correction coefficient is used to correct the brightness ratio value of the three-primary-color LED, thereby generating a standard driving signal to realize the color correction of the three-primary-color LED array board .

Description

Color correction method, color correction device and LED color correction system

Technical Field

The present invention relates to color correction technologies, and in particular, to a color correction method, a color correction device, and an LED color correction system.

Background

Currently, the Light sources of LED display screens and LED backlights are mainly provided by Light Emitting Diodes (LEDs).

The LED display screen is a display screen for displaying various information such as characters, graphics, images, animation, quotation, video, or video. The LED display screen is divided into a picture-text display screen and a video display screen which are both composed of LED matrix blocks.

The color reducibility of the LED backlight greatly exceeds that of a Cold Cathode Fluorescent Lamp (CCFL) backlight, so that the liquid crystal display television mainly adopts the LED backlight. In addition, the dynamic backlight technology of the LED backlight source not only greatly reduces the power consumption of the liquid crystal television adopting the LED backlight source, but also improves the contrast ratio, the color expression and the like of the liquid crystal television. Meanwhile, because the service life of the LED backlight source is very long, which can reach 10 ten thousand hours, the service life of the liquid crystal television adopting the LED backlight source is also very long, for example, if the LED backlight source is started for 5 hours every day, one liquid crystal television adopting the LED backlight source can be used for about 55 years. In addition, it contains no mercury and has good environmental protection performance.

Specifically, the LED backlight used in the lcd tv may be Red, Green and Blue (RGB), and the multi-color LED backlight may also be applied in high-end products to further improve the color expression, for example, a liquid crystal display using a six-primary-color LED backlight is released by mitsubishi motor on SID 2005.

In the prior art, in order to enable light emitted by LEDs to meet requirements of chromaticity and brightness, firstly, chromaticity values and brightness values of LEDs of different primary colors are collected when Pulse Width Modulation (PWM) of driving signals is 100%, and driving signals PWM of LEDs of different primary colors are obtained through a conversion formula according to the chromaticity values and the brightness values of the required colors. And then driving the corresponding three-primary-color LED to emit the required color by using the obtained driving signal PWM of each three-primary-color LED.

Take the example of requiring a three primary LED array board to output white light. Under the condition that the input drive signal PWM is 100%, respectively lighting each red LED, green LED and blue LED on the three-primary-color LED array plate, and collecting the colorimetric value and the brightness value of each red LED, the colorimetric value and the brightness value of each green LED and the colorimetric value and the brightness value of each blue LED, and adopting a formula according to the collected colorimetric values of the three-primary-color LEDs and the preset standard white light colorimetric value

$\left[\begin{array}{c}\mathrm{SPr}\\ \mathrm{SPg}\\ \mathrm{SPb}\end{array}\right]={\left[\begin{array}{ccc}\frac{\mathrm{xr}}{\mathrm{yr}}& \frac{\mathrm{xg}}{\mathrm{yg}}& \frac{\mathrm{xb}}{\mathrm{yb}}\\ 1& 1& 1\\ \frac{1-\mathrm{xr}-\mathrm{yr}}{\mathrm{yr}}& \frac{1-\mathrm{xg}-\mathrm{yg}}{\mathrm{yg}}& \frac{1-\mathrm{xb}-\mathrm{yb}}{\mathrm{yb}}\end{array}\right]}^{-1}\left[\begin{array}{c}\frac{\mathrm{xw}}{\mathrm{yw}}\\ 1\\ \frac{1-\mathrm{xw}-\mathrm{yw}}{\mathrm{yw}}\end{array}\right]---\left(1\right)$

And obtaining the brightness ratio of each tricolor LED, generating a corresponding driving signal PWM according to each brightness ratio, and inputting the driving signal PWM into the corresponding tricolor LED, so that the tricolor LED array plate outputs white light.

However, the obtained driving signal PWM has an error with an actual standard driving signal PWM, so that there are problems such as color spots and bright spots on the entire screen. Taking the three-primary-color LED array board outputting white light as an example, manufacturers need that the three-primary-color LED array board outputting standard white light is (0.31 ), when inputting driving signals PWM to the three-primary-color LED array board, collecting and obtaining red LED chromaticity values, green LED chromaticity values and blue LED chromaticity values of one of the three primary-color LEDs, which are respectively (0.6939, 0.3060) (0.175, 0.7081) (0.1493, 0.0316), and calculating the obtained brightness ratio according to the above formula to be (0.31 ), where

However, the actual standard brightness ratio of the three primary color LED should be

Therefore, the ratio of the brightness obtained by calculationThe generated driving signal PWM cannot make the three primary color LED output a practically standard white light. Therefore, for each three-primary color LED on the three-primary color LED array plate, the driving signal PWM of each three-primary color LED obtained by calculation and the standard of each three-primary color LED actuallyThe driving signal has errors, so that color spots and bright spots appear on the screen.

Disclosure of Invention

The invention aims to provide a color correction method, a color correction device and an LED color correction system, which are used for correcting non-uniformity such as color spots and bright spots caused by display differences of three-primary-color LEDs, so that three-primary-color LED display screens or backlight sources with different brightness and chromaticity can generate uniform white pictures, and the color spots and the bright spots can be effectively eliminated.

To achieve the above object, the present invention provides a color correction method, comprising:

driving a three-primary-color LED array plate to emit light by using three groups of preset driving signals;

collecting three groups of colorimetric values of light emitted by the three-primary-color LED array plate under the driving of the three groups of preset driving signals respectively;

obtaining three groups of theoretical brightness ratio values of the three primary color LEDs in the three primary color LED array plate by utilizing the collected three groups of colorimetric values;

obtaining three groups of actual brightness ratio values of the three primary color LEDs by using the three groups of preset driving signals;

obtaining color correction coefficients through the three groups of theoretical brightness matching values and the three groups of actual brightness matching values;

and correcting the brightness ratio of the three-primary-color LED by using the color correction coefficient so as to generate a standard driving signal to realize color correction of the three-primary-color LED array plate.

To achieve the above object, the present invention also provides a color correction apparatus, comprising:

the driving signal presetting module is used for driving the three-primary-color LED array plate to emit light by using three groups of preset driving signals;

the chromatic value acquisition module is used for acquiring three groups of chromatic values of light emitted by the three-primary-color LED array plate under the drive of the three groups of preset drive signals respectively;

the theoretical brightness ratio generation module is used for obtaining three groups of theoretical brightness ratios of the three primary colors of LEDs in the three primary colors of LED array plates by utilizing the collected three groups of colorimetric values;

the actual brightness ratio value generation module is used for obtaining three groups of actual brightness ratio values of the three primary-color LEDs by utilizing the three groups of preset driving signals;

the color correction coefficient generating module is used for obtaining color correction coefficients through the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values;

and the standard driving signal generation module is used for correcting the brightness ratio of the three-primary-color LED by using the color correction coefficient so as to generate a standard driving signal to realize color correction of the three-primary-color LED array plate.

In order to achieve the above object, the present invention further provides an LED color correction system comprising a color correction device, further comprising the three primary color LED array board, a collection device and an LED control circuit, wherein,

the three-primary-color LED array plate is used for receiving the three groups of preset driving signals or the standard driving signals sent by the color correction device through the LED control circuit;

the collecting device is used for collecting the three groups of colorimetric values of the three groups of preset driving signals for driving the three-primary-color LED array plate to emit light.

According to the technical scheme, the color correction coefficient is generated through the three groups of actual brightness ratio values and the three groups of theoretical brightness ratio values, so that the initial brightness ratio value generated by the initial chromatic value of the three-primary-color LED is corrected, the color correction of the three-primary-color LED array plate is realized by generating the standard driving signal, a three-primary-color LED display screen or a backlight source composed of LEDs with different brightness and chromaticity generates a uniform white picture, and the cost of the three-primary-color LED display screen and the three-primary-color LED backlight source is saved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 is a schematic flow chart illustrating a color correction method according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a color correction apparatus according to a second embodiment of the present invention;

fig. 3 is a schematic structural diagram of an LED color correction system according to a third embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

Fig. 1 is a schematic flow chart of a color correction method according to an embodiment of the present invention, which includes the following specific steps:

step 11, driving a three-primary-color LED array plate to emit light by using three groups of preset driving signals;

step 12, collecting three groups of colorimetric values of light emitted by the three-primary-color LED array plate under the driving of three groups of preset driving signals respectively;

step 13, obtaining three groups of theoretical brightness ratios of the three primary color LEDs in the three primary color LED array plate by utilizing the collected three groups of colorimetric values;

step 14, obtaining three groups of actual brightness ratio values of the three primary color LEDs by using three groups of preset driving signals;

step 15, obtaining color correction coefficients through the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values;

and step 16, correcting the brightness ratio of the tricolor LEDs by using the color correction coefficient so as to generate a standard driving signal to realize color correction of the tricolor LED array plate.

In step 12, three sets of preset driving signals are respectively input to each of the three primary color LEDs on the three primary color LED array board, and three sets of chromaticity values of light emitted by each of the three primary color LEDs when the three sets of preset driving signals are input are respectively collected. The three sets of white light chromaticity values can be represented as (xw1, yw1), (xw2, yw2), (xw3, yw 3).

In step 13, specifically, according to an initial red LED chromaticity value, an initial green LED chromaticity value, and an initial blue LED chromaticity value of the three-primary-color LED, a formula (1) is adopted, so that three sets of theoretical luminance distribution values of the three-primary-color LED in the three-primary-color LED array board can be obtained, taking the case that the three-primary-color LED array board outputs white light as an example, the red LED chromaticity value acquired under the condition that the driving signal PWM is 100% is represented by (xr, yr), the green LED chromaticity value is represented by (xg, yt), and the blue LED chromaticity value is represented by (xb, yb), then three sets of theoretical luminance distribution values can be obtained respectively by adopting the formula (1), which are respectively:

$\left[\begin{array}{c}{\mathrm{SPr}}_1\\ {\mathrm{SPg}}_1\\ {\mathrm{SPb}}_1\end{array}\right]={\left[\begin{array}{ccc}\frac{\mathrm{xr}}{\mathrm{yr}}& \frac{\mathrm{xg}}{\mathrm{yg}}& \frac{\mathrm{xb}}{\mathrm{yb}}\\ 1& 1& 1\\ \frac{1-\mathrm{xr}-\mathrm{yr}}{\mathrm{yr}}& \frac{1-\mathrm{xg}-\mathrm{yg}}{\mathrm{yg}}& \frac{1-\mathrm{xb}-\mathrm{yb}}{\mathrm{yb}}\end{array}\right]}^{-1}\left[\begin{array}{c}\frac{\mathrm{xw}1}{\mathrm{yw}1}\\ 1\\ \frac{1-\mathrm{xw}1-\mathrm{yw}1}{\mathrm{yw}1}\end{array}\right]---\left(2\right)$

$\left[\begin{array}{c}{\mathrm{SPr}}_2\\ {\mathrm{SPg}}_2\\ {\mathrm{SPb}}_2\end{array}\right]={\left[\begin{array}{ccc}\frac{\mathrm{xr}}{\mathrm{yr}}& \frac{\mathrm{xg}}{\mathrm{yg}}& \frac{\mathrm{xb}}{\mathrm{yb}}\\ 1& 1& 1\\ \frac{1-\mathrm{xr}-\mathrm{yr}}{\mathrm{yr}}& \frac{1-\mathrm{xg}-\mathrm{yg}}{\mathrm{yg}}& \frac{1-\mathrm{xb}-\mathrm{yb}}{\mathrm{yb}}\end{array}\right]}^{-1}\left[\begin{array}{c}\frac{\mathrm{xw}2}{\mathrm{yw}2}\\ 1\\ \frac{1-\mathrm{xw}2-\mathrm{yw}2}{\mathrm{yw}2}\end{array}\right]---\left(3\right)$

$\left[\begin{array}{c}{\mathrm{SPr}}_3\\ {\mathrm{SPg}}_3\\ {\mathrm{SPb}}_3\end{array}\right]={\left[\begin{array}{ccc}\frac{\mathrm{xr}}{\mathrm{yr}}& \frac{\mathrm{xg}}{\mathrm{yg}}& \frac{\mathrm{xb}}{\mathrm{yb}}\\ 1& 1& 1\\ \frac{1-\mathrm{xr}-\mathrm{yr}}{\mathrm{yr}}& \frac{1-\mathrm{xg}-\mathrm{yg}}{\mathrm{yg}}& \frac{1-\mathrm{xb}-\mathrm{yb}}{\mathrm{yb}}\end{array}\right]}^{-1}\left[\begin{array}{c}\frac{\mathrm{xw}3}{\mathrm{yw}3}\\ 1\\ \frac{1-\mathrm{xw}3-\mathrm{yw}3}{\mathrm{yw}3}\end{array}\right]---\left(4\right)$

wherein, SPr₁、SPg₁And SPb₁The ratio of the theoretical red LED brightness, the theoretical green LED brightness and the theoretical blue LED brightness of the first group is respectively;

SPr₂、SPg₂and SPb₂The ratio of the theoretical red LED brightness, the theoretical green LED brightness and the theoretical blue LED brightness of the second group is respectively;

Spr₃、SPg₃and SPb₃And the ratio of the theoretical red LED brightness, the theoretical green LED brightness and the theoretical blue LED brightness of the third group are respectively.

In this embodiment, the color correction coefficient is generated by three sets of actual luminance ratio values and three sets of theoretical luminance ratio values, so that the initial luminance ratio value generated by the initial chromaticity value of the three-primary-color LED is corrected to generate a standard driving signal to realize color correction of the three-primary-color LED array board, so that a uniform white picture is generated on a three-primary-color LED display screen or a backlight source composed of LEDs with different luminances and chromaticities, and further, the costs of the three-primary-color LED display screen and the three-primary-color LED backlight source are saved.

Based on the above embodiment, taking the three primary color LED array board to output white light as an example, step 14 specifically includes:

three groups of preset driving signals are utilized, and a formula is adopted according to the initial red LED brightness value, the initial green LED brightness value and the initial blue LED brightness value of the three primary colors of LEDs

$\left[\begin{array}{c}{\mathrm{Lr}}_n\\ {\mathrm{Lg}}_n\\ {\mathrm{Lb}}_n\end{array}\right]=\left[\begin{array}{c}{\mathrm{PWMr}}_n*\mathrm{Lr}\\ {\mathrm{PWMg}}_n*\mathrm{Lb}\\ {\mathrm{PWMb}}_n*\mathrm{Lg}\end{array}\right]---\left(5\right)$

Generating three groups of actual brightness matching values, wherein Lr_n、Lg_nAnd Lb_nRepresenting an nth set of actual red LED luminance values, actual green LED luminance values, and actual blue LED luminance values;

PWMr_n、PWMg_nand PWMb_nDrive signals representing a 2 nd set of preset red, green and blue LEDs;

lr, Lb, and Lg represent initial red LED luminance values, initial green LED luminance values, and initial blue LED luminance values.

Specifically, three groups of actual luminance distribution ratios can be obtained through the formula (5) respectively as follows:

$\left[\begin{array}{c}\mathrm{Lr}1\\ \mathrm{Lg}1\\ \mathrm{Lb}1\end{array}\right]=\left[\begin{array}{c}\mathrm{PWMr}1*\mathrm{Lr}\\ \mathrm{PWMg}1*\mathrm{Lb}\\ \mathrm{PWMb}1*\mathrm{Lg}\end{array}\right]---\left(6\right)$

$\left[\begin{array}{c}\mathrm{Lr}2\\ \mathrm{Lg}2\\ \mathrm{Lb}2\end{array}\right]=\left[\begin{array}{c}\mathrm{PWMr}2*\mathrm{Lr}\\ \mathrm{PWMg}2*\mathrm{Lb}\\ \mathrm{PWMb}2*\mathrm{Lg}\end{array}\right]---\left(7\right)$

$\left[\begin{array}{c}\mathrm{Lr}3\\ \mathrm{Lg}3\\ \mathrm{Lb}3\end{array}\right]=\left[\begin{array}{c}\mathrm{PWMr}3*\mathrm{Lr}\\ \mathrm{PWMg}3*\mathrm{Lb}\\ \mathrm{PWMb}3*\mathrm{Lg}\end{array}\right]---\left(8\right)$

on the basis of the above embodiment, taking the three primary color LED array board to output white light as an example, step 15 specifically includes:

and substituting the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values into the following formula:

$\left[\begin{array}{c}{\mathrm{Lr}}_n\\ {\mathrm{Lg}}_n\\ {\mathrm{Lb}}_n\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{c}{\mathrm{SPr}}_n\\ {\mathrm{SPg}}_n\\ {\mathrm{SPb}}_n\end{array}\right]---\left(9\right)$

for the sake of simple calculation, the three groups of theoretical luminance ratio values and the three groups of actual luminance ratio values may be normalized, in this embodiment, the third term of the three groups of theoretical luminance ratio values and the three groups of actual luminance ratio values is normalized, for example, the third term of the three groups of theoretical luminance ratio values and the three groups of actual luminance ratio values are normalized

Andis normalized to obtain

And

the third terms of the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values are normalized and then are substituted into a formula (9) to respectively obtain:

$\left[\begin{array}{c}\frac{{\mathrm{Lr}}_1}{{\mathrm{Lb}}_1}\\ \frac{{\mathrm{Lg}}_1}{{\mathrm{Lb}}_1}\\ 1\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{c}\frac{{\mathrm{SPr}}_1}{{\mathrm{SPb}}_1}\\ \frac{{\mathrm{SPg}}_1}{{\mathrm{SPb}}_1}\\ 1\end{array}\right]---\left(10\right)$

$\left[\begin{array}{c}\frac{{\mathrm{Lr}}_2}{{\mathrm{Lb}}_2}\\ \frac{{\mathrm{Lg}}_2}{{\mathrm{Lb}}_2}\\ 1\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{c}\frac{{\mathrm{SPr}}_2}{{\mathrm{SPb}}_2}\\ \frac{{\mathrm{SPg}}_2}{{\mathrm{SPb}}_2}\\ 1\end{array}\right]---\left(11\right)$

$\left[\begin{array}{c}\frac{{\mathrm{Lr}}_3}{{\mathrm{Lb}}_3}\\ \frac{{\mathrm{Lg}}_3}{{\mathrm{Lb}}_3}\\ 1\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{c}\frac{{\mathrm{SPr}}_3}{{\mathrm{SPb}}_3}\\ \frac{{\mathrm{SPg}}_3}{{\mathrm{SPb}}_3}\\ 1\end{array}\right]---\left(12\right)$

the color correction coefficient is solved by the following equations (10), (11) and (12) $\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right].$

Wherein,

for the color correction coefficients, x1 to x3 are color correction coefficients of a red LED, y1 to y3 are color correction coefficients of a green LED, and z1 to z3 are color correction coefficients of a blue LED, respectively.

Based on the above embodiment, taking the three primary color LED array board to output white light as an example, step 16 specifically includes:

according to the color correction coefficient, the following formula is adopted:

$\left[\begin{array}{c}\mathrm{Pr}\\ \mathrm{Pg}\\ \mathrm{Pb}\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{c}\mathrm{SPr}\\ \mathrm{SPg}\\ \mathrm{SPb}\end{array}\right]---\left(13\right)$

and generating a standard brightness matching value. For simple calculation, the initial theoretical brightness ratio value may be normalized first, and in this embodiment, the third term of the initial theoretical brightness ratio value may be normalized, specifically, the third term of the initial theoretical brightness ratio value is normalizedNormalized to

And substituted into equation (13):

$\left[\begin{array}{c}\mathrm{Pr}\\ \mathrm{Pg}\\ \mathrm{Pb}\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{c}\frac{\mathrm{SPr}}{\mathrm{SPb}}\\ \frac{\mathrm{SPg}}{\mathrm{SPb}}\\ 1\end{array}\right]---\left(14\right)$

for simple calculation, the ratio of standard brightnessThe third term is normalized to obtain

Starting order

Then, according to the initial red LED brightness value, the initial green LED brightness value and the initial blue LED brightness value of the three primary color LEDs and the preset target brightness value, respectively substituting the following formulas:

$\mathrm{PWMr}=a*\frac{\mathrm{Lu}\min \mathrm{ancet}\arg \mathrm{et}}{(a+b+1)*\mathrm{Lr}}---\left(15\right)$

$\mathrm{PWMg}=b*\frac{\mathrm{Lu}\min \mathrm{ancet}\arg \mathrm{et}}{(a+b+1)*\mathrm{Lg}}---\left(16\right)$

$\mathrm{PWMb}=\frac{\mathrm{Lu}\min \mathrm{ancet}\arg \mathrm{et}}{(a+b+1)\mathrm{Lb}}---\left(17\right)$

obtaining standard driving signals of a red LED, a green LED and a blue LED of the corrected tricolor LED, thereby realizing color correction of the tricolor LED array plate;

wherein, the luminencetarget represents a preset target brightness value;

PWMr, PWMg, and PWMb represent standard driving signals after correction of red, green, and blue LEDs;

SPr, SPg, and SPb represent the ratio of the red LED luminance, the green LED luminance, and the blue LED luminance of the three primary color LEDs at a driving signal PWM of 100%;

pr, Pg, and Pb represent the ratio of the standard red LED luminance, the standard green LED luminance, and the standard blue LED luminance.

It should be noted that, in the embodiment of the present invention, in order to provide the accuracy of color correction, the three-primary-color LED array board may be further driven to emit light by using 3 × n sets of preset driving signals, so as to obtain n color correction coefficients, so as to generate standard driving signals to implement the color correction of the three-primary-color LED array board.

For example, six sets of preset driving signals are used to drive the three-primary-color LED array plate to emit light, and two color correction coefficients, specifically two color correction coefficients, are generated according to the color correction methodTo knowFinally, the initial luminance ratio value generated by the initial chromaticity values of the three primary color LEDs is corrected according to formula (18):

$\left[\begin{array}{c}\mathrm{Pr}\\ \mathrm{Pg}\\ \mathrm{Pb}\end{array}\right]=\left[\begin{array}{ccc}x1& x2& x3\\ y1& y2& y3\\ z1& z2& z3\end{array}\right]\left[\begin{array}{ccc}m1& m2& m3\\ n1& n2& n3\\ v1& v2& v3\end{array}\right]\left[\begin{array}{c}\frac{\mathrm{SPr}}{\mathrm{SPb}}\\ \frac{\mathrm{SPg}}{\mathrm{SPb}}\\ 1\end{array}\right]---\left(17\right)$

thereby generating a standard brightness ratio value and further generating a standard driving signal to realize the color correction of the three-primary-color LED array plate.

Example two

Fig. 2 is a schematic structural diagram of a color correction apparatus according to a second embodiment of the present invention, and as shown in fig. 2, the color correction apparatus 20 includes a driving signal presetting module 21, a chrominance value obtaining module 22, a theoretical luminance ratio value generating module 23, an actual luminance ratio value generating module 24, a color correction coefficient generating module 25, and a standard driving signal generating module 26.

The driving signal presetting module 21 is used for driving the three-primary-color LED array plate to emit light by using three groups of preset driving signals; the colorimetric value acquisition module 22 is configured to acquire three sets of colorimetric values of light emitted by the three-primary-color LED array board under the driving of three sets of preset driving signals, respectively; the theoretical brightness ratio value generation module 23 is configured to obtain three groups of theoretical brightness ratio values of the three primary color LEDs in the three primary color LED array board by using the collected three groups of colorimetric values; an actual brightness ratio value generation module 24, configured to obtain three sets of actual brightness ratio values according to three sets of preset driving signals; a color correction coefficient generating module 25, configured to obtain color correction coefficients according to the three groups of theoretical luminance ratio values and the three groups of actual luminance ratio values; and the standard driving signal generating module 26 is configured to correct the initial luminance ratio value generated by the initial chromaticity values of the three primary color LEDs by using the color correction coefficient, so as to generate a standard driving signal to implement color correction of the three primary color LED array board.

Further, the standard driving signal generating module 26 specifically includes: a standard brightness ratio value generating module 261, a normalizing module 262, a red LED standard driving signal generating module 263, a green LED standard driving signal generating module 264 and a blue LED standard driving signal generating module 265.

Wherein, the standard brightness matching value generating module 261 is used for generating a formula according to the color correction coefficient

Obtaining a standard brightness ratio;

a normalization module 262 for ratioing the standard luminance

The third term is normalized to obtain

And order $\frac{\mathrm{Pr}}{\mathrm{Pb}}=a,$ $\frac{\mathrm{Pg}}{\mathrm{Pb}}=b;$

A red LED standard driving signal generating module 263, configured to generate a standard driving signal according to the red LED brightness values of the three primary LEDs, a preset target brightness value, and a formulaObtaining a standard driving signal of a red LED of the corrected tricolor LED;

a green LED standard driving signal generating module 264, configured to generate a formula according to the green LED brightness values of the three primary LEDs, a preset target brightness value, and a formulaObtaining a standard driving signal of a green LED of the corrected tricolor LED;

a blue LED standard driving signal generating module 265, configured to generate a target brightness according to the blue LED brightness values of the three primary color LEDs and a preset target brightnessValue of, and formula

And obtaining the standard driving signal of the blue LED of the corrected tricolor LED.

In this embodiment, the working procedure of the color correction apparatus 20 specifically includes: the driving signal presetting module 21 drives the three-primary-color LED array board to emit light by three sets of preset driving signals, then collects three sets of colorimetric values of light emitted by the three-primary-color LED array board under the driving of the three sets of preset driving signals respectively by the colorimetric value obtaining module 22, inputs the three sets of colorimetric values into the theoretical brightness ratio generating module 23 for generating three sets of theoretical brightness ratio values, inputs three sets of actual brightness ratio values obtained by the three sets of preset driving signals into the color correction coefficient generating module 25 by the three sets of theoretical brightness ratio values and actual brightness ratio value generating module 24 for generating color correction coefficients, then inputs the color correction coefficients into the standard brightness ratio value generating module 261 in the standard driving signal generating module 26 for generating standard brightness ratio values, and then normalizes the standard brightness ratio values by the normalizing module 262, the normalized value, and the initial red LED luminance value, the initial green LED luminance value, and the initial blue LED luminance value of the initial three-primary-color LED are respectively substituted into the red LED standard driving signal generating module 263, the green LED standard driving signal generating module 264, and the blue LED standard driving signal generating module 265, so as to obtain the standard driving signal of the corrected three-primary-color LED.

In this embodiment, the color correction device generates the color correction coefficient by using the three sets of actual luminance ratio values and the three sets of theoretical luminance ratio values, so as to correct the initial luminance ratio value generated by the initial chromaticity value of the three-primary-color LED, and generate the standard driving signal to realize the color correction of the three-primary-color LED array board, so that the three-primary-color LED display screen or the backlight source composed of LEDs with different luminances and chromaticities generates a uniform white picture, and further, the cost of the three-primary-color LED display screen and the three-primary-color LED backlight source is saved.

EXAMPLE III

Fig. 3 is a schematic structural diagram of an LED color correction system according to a third embodiment of the present invention, and the third embodiment of the present invention provides an LED color correction system including a color correction device 20, as shown in fig. 3, the LED color correction system further includes: the device comprises a three-primary-color LED array plate 31, a collecting device 32 and an LED control circuit 33, wherein the three-primary-color LED array plate 31 is used for receiving three groups of preset driving signals or standard driving signals sent by the color correction device 20 through the LED control circuit 33; and the collecting device 32 is used for collecting three groups of colorimetric values of the three groups of preset driving signals for driving the three-primary-color LED array plate 31 to emit light.

In particular, the collecting device 32 may be embodied as a set of CCD camera devices, and the collecting device 32 is connected to the color correction device 20.

By adopting the color correction system provided by the third embodiment of the invention, the color correction coefficient can be generated by the acquisition device according to the three groups of actual brightness ratio values and the three groups of theoretical brightness ratio values, so that the initial brightness ratio value generated by the initial chromatic value of the three-primary-color LED is corrected to generate the standard driving signal to realize the color correction of the three-primary-color LED array plate, and therefore, a three-primary-color LED display screen or a backlight source formed by LEDs with different brightness and chromaticity can generate uniform white pictures, and the cost of the three-primary-color LED display screen and the three-primary-color LED backlight source can be further saved.

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the invention without departing from the spirit and scope of the invention.

Claims (7)

1. A color correction method, characterized in that, comprising: Use three sets of pre-set driving signals to drive the tri-color LED array board to emit light; Collecting three sets of chromaticity values of the light emitted by the three-primary-color LED array board respectively driven by the three sets of preset driving signals; Using the collected three sets of chromaticity values to obtain three sets of theoretical brightness ratio values of the three primary colors LEDs in the three primary colors LED array board; Obtaining three sets of actual brightness ratio values of the three primary color LEDs by using the three sets of preset driving signals; Obtaining a color correction coefficient through the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values; The color correction coefficients are used to correct the brightness ratio values of the three-primary-color LEDs, so as to generate standard driving signals to realize the color correction of the three-primary-color LED array board. 2. The color correction method according to claim 1, wherein the three sets of actual brightness ratio values of the three primary color LEDs are obtained by using the three sets of preset driving signals, comprising: Using the three sets of preset drive signals, and the formula

Get three sets of actual brightness ratio values; Among them, Lr _n , Lg _n and Lb _n represent the actual red LED brightness value, the actual green LED brightness value and the actual blue LED brightness value of the nth group; PWMr _n , PWMg _n and PWM _b represent the driving signals of the nth group of preset red LEDs, green LEDs and blue LEDs; Lr, lb and Lg represent the red LED brightness value, the green LED brightness value and the blue LED brightness value of the three primary color LEDs when the driving signal PWM is 100%; n is 1, 2, 3. 3. The color correction method according to claim 1, wherein the color correction coefficients are obtained through the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values, comprising: Through the three groups of theoretical brightness ratio values and the three groups of actual brightness ratio values, and the formula

Get the color correction coefficient; in,

is the color correction coefficient, x1~x3 are the color correction coefficients of the red LED, y1~y3 are the color correction coefficients of the green LED, z1~z3 are the color correction coefficients of the blue LED; SPr _n , SPg _n and SPb _n represent the ratio values of theoretical red LED brightness, theoretical green LED brightness and theoretical blue LED brightness of group n; n is 1, 2, 3. 4. The color correction method according to claim 1, wherein the color correction coefficient is used to correct the brightness ratio value of the three-primary-color LED, thereby generating a standard driving signal to realize the three-primary-color LED array board color correction, including: According to the color correction coefficients, and the formula

Obtain the standard brightness ratio value; Ratio value for standard brightness

The third term is normalized to get

and order

According to the initial red LED luminance value of the three primary color LEDs and the preset target luminance value, and the formula Obtain the standard driving signal of the red LED of the three primary color LEDs after correction; According to the initial green LED luminance value of the three primary color LEDs and the preset target luminance value, and the formula

Obtain the standard driving signal of the green LED of the three primary color LEDs after correction; According to the initial blue LED luminance value of the three primary color LEDs and the preset target luminance value, and the formula

Obtain the standard driving signal of the blue LED of the three primary color LEDs after correction; Among them, Luminancetarget represents a preset target luminance value; PWMr, PWMg and PWMb represent the corrected standard drive signals for red LED, green LED and blue LED; SPr, SPg and SPb represent the ratio values of the red LED brightness, green LED brightness and blue LED brightness of the three primary color LEDs when the driving signal PWM is 100%; Pr, Pg and Pb represent the ratio values of standard red LED brightness, standard green LED brightness and standard blue LED brightness. 5. A color correction device, characterized in that it comprises: The drive signal preset module is used to drive the tri-color LED array board to emit light with three sets of preset drive signals; A chromaticity value acquisition module, configured to collect three sets of chromaticity values of the light emitted by the three-primary-color LED array board driven by the three sets of preset driving signals; A theoretical brightness ratio generating module, configured to use the collected three groups of chromaticity values to obtain three groups of theoretical brightness ratio values of the three primary color LEDs in the tri-primary LED array board; An actual brightness ratio generating module, configured to use the three sets of preset driving signals to obtain three groups of actual brightness ratio values of the three primary color LEDs; A color correction coefficient generation module, configured to obtain a color correction coefficient through the three sets of theoretical brightness ratio values and the three groups of actual brightness ratio values; The standard driving signal generating module is configured to use the color correction coefficient to correct the brightness ratio value of the three-primary-color LED, so as to generate a standard driving signal to realize the color correction of the three-primary-color LED array board. 6. The color correction device according to claim 5, wherein the standard driving signal generating module specifically comprises: A standard brightness ratio value generation module, used to correct the coefficient according to the color and the formula

Obtain the standard brightness ratio value; Normalization module, used to match the standard brightness ratio value

The third term is normalized to get

and order

Red LED standard drive signal generating module, used for red LED luminance value and preset target luminance value according to the three primary color LEDs, and the formula

Obtain the standard driving signal of the red LED of the three primary color LEDs after correction; Green LED standard drive signal generation module, used for green LED luminance value and preset target luminance value according to the three primary color LEDs, and the formula

Obtain the standard driving signal of the green LED of the three primary color LEDs after correction; The blue LED standard driving signal generation module is used for rooting the blue LED luminance value and the preset target luminance value according to the three primary color LEDs, and the formula

Obtain the standard driving signal of the blue LED of the three primary color LEDs after correction; Among them, Luminancetarget represents a preset target luminance value; PWMr, PWMg and PWMb represent the corrected standard drive signals for red LED, green LED and blue LED; SPr, SPg and SPb represent the ratio values of the red LED brightness, green LED brightness and blue LED brightness of the three primary color LEDs when the driving signal PWM is 100%; Pr, Pg and Pb represent the ratio values of standard red LED brightness, standard green LED brightness and standard blue LED brightness. 7. An LED color correction system comprising the color correction device according to any one of claims 5 to 6, further comprising the three-primary-color LED array board, a collection device and an LED control circuit, wherein, The three-primary-color LED array board is used to receive the three sets of preset driving signals or the standard driving signals sent by the color correction device through the LED control circuit; The acquisition device is configured to acquire the three sets of chromaticity values for driving the three-primary-color LED array board to emit light by the three sets of preset driving signals.

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