TWI430251B - Color correction system of a color sequential display and the method thereof - Google Patents

Description

Color correction system and method thereof

The present invention relates to a color correction method, and more particularly to a color correction method for use in a color sequential display.

In the past liquid crystal display, a color filter was arranged above the pixel to filter the light source to display the color to be displayed, and the human eye received the red, green and blue light displayed by the light source after passing through the color filter. Mix them to perceive the color of this pixel. However, the color filter affects the overall light transmittance of the liquid crystal display. In addition, the color filter also affects the dot size of the single pixel of the liquid crystal display, resulting in the color resolution of the liquid crystal display being affected by the color filter. The limitations of the film.

In order to improve the above-mentioned problems such as resolution and light transmittance, a color Sequential liquid crystal display has been developed today. The color sequential liquid crystal display can sequentially display the three primary color components of one pixel to present color. Each pixel of the color sequential liquid crystal display emits red, green and blue light as backlights by three illumination sources. In a frame time, the pixels can respectively turn on red, green, and blue light according to the display data. By using the visual persistence of the human eye, one can recognize the color of this pixel. Therefore, the color sequential liquid crystal display does not need to be provided with a color filter, and since each pixel of the color sequential liquid crystal display has a smaller size than each pixel of the liquid crystal display with a color filter, the color sequential liquid crystal display Reduce costs and increase resolution.

For the purpose of white balance compensation and color correction, a color correction system commonly used in a color sequential liquid crystal display is substantially as shown in FIG. 1 , and includes a timing controller 101 , a color controller 102 , and a light emitting diode driver 103 . The light emitting diode 104, the gate controller 105, the source controller 106, the liquid crystal panel 107, and the sensor 108. The sensor 108 is coupled to the timing controller 101, the color controller 102 is embedded in the timing controller 101, and can also be coupled to the timing controller 101. The LED driver 103 is coupled to the timing controller 101. The plurality of light emitting diodes 104 are coupled to the light emitting diode driver 103, and the gate controller 105 and the source controller 106 are coupled to the timing controller 101, respectively, to control the operation of the pixels in the liquid crystal panel 107. The arithmetic unit or the color controller 102 may also be disposed outside the timing controller 101 and coupled to the timing controller 101 without being limited to the timing controller 101. The driving mode of the pixel is outputted by the timing controller 101 to the gate controller 105 and the source controller 106, respectively, thereby controlling the pixel voltage in the liquid crystal panel 107, and the color controller 102 in the timing controller 101. The brightness value corrected by the LED driver 103 is provided according to a look up table, thereby driving the LED 204 to display an appropriate color and white balance, wherein the lookup table can be stored in the timing controller 101 or In the color controller 102. The sensor 108 can include a color detector, a temperature detector, and a photodetector. According to different types of sensors 108, the color correction system operates in the following three ways:

The first type uses a color sensor to detect the intensity of red, green, and blue light emitted by the RGB light-emitting diodes, and then transmits it to the color controller in the Timing Controller (TCON). The operation and compensation mechanism is controlled by the LED driver to control the load or current of the LED to display the desired brightness, thereby achieving the purpose of color correction.

The second method uses a temperature sensor to detect the temperature change of the light-emitting diode, and returns the detection result to the color controller according to the temperature and the red, green and blue light emitting diodes. The table adjusts the load or current of the above-mentioned light-emitting diode to achieve the purpose of color correction.

The third method uses a light sensor to obtain the luminance values of the red, green, and blue light emitting diodes in a time-sharing manner, and returns the detection result to the color controller. Whether the brightness of any of the above-mentioned light-emitting diodes is attenuated by the look-up table, if the brightness is found to be attenuated, the brightness of the light-emitting diode can be compensated for the desired white balance, thereby achieving the purpose of color correction. .

Since the color sequential liquid crystal display sequentially projects sub-pictures of three consecutive color fields into the human eye to synthesize color images in the brain, if there is a relative speed between the human eye and the image (for example, when the display is stationary) When the human eye is moving, or when the display moves, the human eye is still.) The three sub-pictures projected will not overlap completely on the retina, but will be misplaced at the edge of the image. The accumulation will make the human eye unable to view clear images, which will seriously affect the image quality of the display. This phenomenon is also called color breakup phenomenon.

With the continuous breakthrough and advancement of technology, many methods for solving this problem have been proposed in recent years. The most common method is to insert sub-color fields of other colors in each color field of the color sequential liquid crystal display, and use the superposition principle of colors to make The difference in color of the staggered edges is reduced, thereby suppressing the perception of color separation by the human eye. For example: RGBW color sequential method, RGBCY color sequential method, WmaxRGB, RwGwBw color sequential method, RwGwBwGw color sequential method, and the like.

However, although the above method can effectively suppress the generation of the color separation phenomenon, since each color field is inserted into the sub-color field of other colors instead of a single color, only the color mixture can be obtained when the photo sensor is used for detection. The brightness of light, not the brightness of monochromatic light, makes color correction and compensation impossible.

Therefore, in the technique related to the color sequential display, if the color separation phenomenon is suppressed at the same time and the normal color correction and compensation are maintained, there are still some technical difficulties to be overcome.

In order to overcome the above difficulties and disadvantages, the present invention provides a color correction method, particularly a color correction method and system for a color sequential display that suppresses color separation.

One of the objectives of the present invention is to convert the brightness of the mixed color light detected by the light sensor into the brightness of the solid color of red, green and blue, and to correct and compensate for the color.

Another object of the present invention is to provide a color sequential display that can simultaneously suppress color separation and maintain normal color correction and compensation functions. It should be noted that the above color sequential method may include, but is not limited to, RGBW color sequential method, RGBCY color sequential method, WmaxRGB, RwGwBw color sequential method, and RwGwBwGw color sequential method.

In order to achieve the above object, the present invention provides a color correction method for a color sequential display, the method comprising: detecting, by a light sensor, brightness values of a first color field, a second color field, and a third color field (R) _W , G _W , B _W ); using an arithmetic unit to perform an operation on the detection result of the photosensor to obtain a solid color luminance value (R, G, B) of red, green, and blue; The color controller corrects the brightness values of the red, green, and blue solid colors; and transmits the red, green, and blue solid color brightness values corrected by the color controller to a light emitting diode driver; wherein The luminance value of the first color field is defined as R _W = R + xG + iB, the luminance value of the second color field is defined as G _W = mR + G + jB, and the luminance value of the third color field is defined as B _W =nR+yG+B, where 0 x, y, i, j, m, n < 1, and the above arithmetic unit operates in the following matrix:

In another aspect, the present invention further provides a color correction system for a color sequential display, comprising: a light sensor for detecting brightness values of the first color field, the second color field, and the third color field (R) _W , G _W , B _W ); a timing controller electrically coupled to the photo sensor; an arithmetic unit located in the timing controller for performing an operation on the detection result of the photo sensor Obtaining a solid color brightness value (R, G, B) of red, green, and blue; a color controller electrically coupled to the timing controller and the arithmetic unit for the solid color light of the red, green, and blue colors The brightness value is corrected; and a light emitting diode driver is electrically coupled to the timing controller for receiving the corrected brightness values of the red, green, and blue colors; wherein, the brightness of the first color field The value is defined as R _W =R+xG+iB, the brightness value of the second color field is defined as G _W =mR+G+jB, and the brightness value of the third color field is defined as B _W =nR+yG+B, Among them, 0 x, y, i, j, m, n < 1, and the above arithmetic unit operates in the following matrix:

By the above technical means, the brightness value of the mixed color light detected by the light sensor can be converted into the true solid color light brightness value emitted by the red, green and blue light emitting diodes, thereby effectively performing subsequent color correction and Compensate to show the proper color and white balance.

The above is used to clarify the object of the present invention, the technical means for achieving the object, the advantages thereof, and the like. The invention will be apparent to those skilled in the art from the description of the appended claims.

The present invention will be described in terms of the preferred embodiments and aspects of the invention, which are intended to be illustrative and not to limit the scope of the invention. Therefore, the present invention may be widely practiced in other embodiments in addition to the preferred embodiments described in the specification.

The invention utilizes an arithmetic unit to convert the brightness of the mixed color light detected by the light sensor into the brightness of the solid color of red, green and blue according to the proportional relationship between the brightness and the current of the light emitting diode and through the matrix operation. In order to facilitate the checklist for color correction and compensation.

The color correction system disclosed in the present invention is first introduced. Referring to FIG. 2, the figure depicts a preferred embodiment of a color sequential display using the color correction system of the present invention, comprising: a timing controller 101, a The color controller 102, a light emitting diode driver 103, a plurality of light emitting diodes 104, a gate controller 105, a source controller 106, a liquid crystal panel 107, an arithmetic unit 201, and a light sensor 202 . The arithmetic unit 201 can be embedded in the color controller 102, and the color controller 102 is coupled to the timing controller 101. In some embodiments, the operation unit 201 and the color controller 102 may also be disposed outside the timing controller 101, and the three are electrically coupled to each other. The photo sensor 202 and the LED driver 103 are respectively coupled to the timing controller 101, and the gate controller 105 and the source controller 106 are also coupled to the timing controller 101, respectively, to control the pixels in the liquid crystal panel 107. Actuate. The plurality of light emitting diodes 104 are coupled to the light emitting diode driver 103 to provide the desired color. The photo sensor 202 is coupled to the timing controller 101, which can detect the brightness values of the plurality of color fields by means of time-sharing detection, and only needs three color fields to calculate the brightness value of the solid color light. After obtaining the brightness values of the at least three color fields, the photo sensor 202 can transmit the detected mixed color light brightness value to the color controller 102, and the operation unit 201 can obtain the detection by the color controller 102. The result is calculated and the brightness value of the solid color light is obtained. The color controller 102 can receive the brightness value of the solid color light calculated by the operation unit 201, and check whether the brightness value of the solid color light is normal or attenuated according to the lookup table, and then compensate the brightness value by the result, wherein the lookup table can be stored in the In the color controller 102 or the timing controller 101. In addition, the driving mode of the liquid crystal pixels is outputted by the timing controller 101 to the gate controller 105 and the source controller 106, respectively, thereby controlling the pixel voltage in the liquid crystal panel 107, which is known to those skilled in the art. Know, so I won't go into details.

The color sequential method applied by the present invention may include RGBW color sequential method, RGBCY color sequential method, WmaxRGB, RwGwBw color sequential method, RwGwBwGw color sequential method, etc., but each color field method of the above color sequential method is not a separate solid color light. And the mixed color of the other color is doped, that is, if the first color field detected by the photo sensor 202 is mainly red light, the detected brightness is R _W =R+G _r +B _r , where R is the desired red solid color brightness, and G _r and B _r are the brightness of the green light emitting diode and the blue light emitting diode respectively in this color place; if the second color field is mainly For green light, the brightness is G _W =R _g +G+B _g , where G is the desired green solid color brightness, and R _g and B _g are the red light emitting diode and the blue light emitting diode, respectively. The brightness displayed in the color field; if the third color field is mainly blue light, the brightness is B _W = R _b + G _b + B, where B is the desired blue solid color brightness, and R _b and G _b is the brightness of the red light-emitting diode and the green light-emitting diode in this color place. It should be noted that the order of the first color field, the second color field, and the third color field is only an embodiment for the purpose of illustration and not limitation.

In order to obtain the brightness of the pure color light (R, G, B in the above mathematical formula), the present invention can be operated by the operation unit 201 according to the relationship between the brightness and the current of the light-emitting diode, which can be referred to FIG. The relationship between the brightness and current of the light-emitting diode is obvious from the figure. The brightness and current curves of the light-emitting diode can be roughly divided into a linear region and a saturated region. In order to facilitate the control, it is usually operated in a linear region, in other words, The brightness of the display is linearly proportional to the applied current. Therefore, R, R _g and R _b are linear, so they can be defined as R _g =mR, R _b =nR, since R _g and R _b are only doped in the second color field and part of the third color field. The brightness value is therefore less than R, so m, n should be less than 1. Similarly, G, G _r and G _b are linear, which can be defined as G _r =xG, G _b =yG, and due to G _r And G _b is only a part of the green light intensity value doped in the first color field and the third color field, so it must be smaller than G, so x, y should be less than 1; similarly, B _r and B _g can be defined as B _r = iB, B _g = jB, since B _r and B _g are only the partial blue light luminance values doped in the first color field and the second color field, and must be smaller than B, so i, j should be less than 1. After the above algebraic conversion, the first color field brightness value can be defined as R _W =R+xG+iB, the second color field brightness value is G _W =mR+G+jB, and the third color field brightness value is B. _W = nR + yG + B. According to the above mathematical formula, the operation unit 201 can perform operations based on the following matrix:

Among them, m, n, x, y, i, j are set by the user to eliminate the color separation phenomenon, so these values are known numbers. The R _W , G _W and B _W are detected by the photo sensor 202 in a time-sharing manner, and are also known numbers. Therefore, the R, G, and B values can be obtained by using these known numbers. The above mathematical formula is calculated to obtain the luminance values of the solid colors of red, green and blue to facilitate subsequent color correction and compensation. It should be noted that if there is no absolute linear relationship between the brightness and current of the LED, the relationship between the two can still be obtained according to the specification of the LED (spec), in order to obtain the brightness value of the solid color. .

Referring to FIG. 4, this figure discloses an embodiment of the first, second, and third color fields of the present invention. It can be observed that the brightness R of the red light-emitting diode in the first color field 301 is the highest. The display brightness of the two-color field 302 is 0.3R, the display brightness of the third color field 303 is 0.2R, that is, m=0.3, n=0.2; the display brightness G of the green light-emitting diode in the second color field 302 is The highest brightness in the first color field 301 is 0.1G, and the brightness in the third color field 303 is also 0.1G, that is, x=0.1, y=0.1; the blue light emitting diode is in the third color field 303. The brightness B is the highest, the display brightness in the first color field 301 is 0.2B, and the display brightness in the second color field 302 is 0.1B, that is, i=0.2, j=0.1. Assuming that the brightness R is 80 nits, the brightness G is 200 nits, and the brightness B is 20 nits, it can be estimated that the first color field brightness detected by the photo sensor should be R _W =80+0.1 G+0.2B=80+20+4=104, the second color field brightness should be G _W =0.3R+200+0.1B=226, and the third color field brightness should be B _W =0.2R+0.1B+20 =56, the above values are brought into the aforementioned matrix and the operation is as follows:

The results obtained from the above matrix are R = 80, G = 200, and B = 20, which are exactly equal to the originally assumed values, and further prove that the present invention can obtain the correct pure color luminance value.

Referring to FIG. 5, this figure illustrates an implementation flow of the present invention. The steps are as follows: First, at step 401, the display is activated by the user, and then, at step 402, determined by the timing controller or the color controller. Whether the backlight module is turned on, if it is determined to be turned on, the process proceeds to step 403, and the color field sensor is used to detect the mixed color light brightness values of the first color field, the second color field, and the third color field by means of time-sharing detection. (R _W , G _W , B _W ), then in step 404, it is confirmed by the timing controller or the color controller whether the detection is completed. If not, the process returns to step 403 to continue the detection, and if it is completed, the process proceeds to the step. 405, using an arithmetic unit to convert the mixed color light luminance value into red, green, and blue solid color light luminance values (R, G, B) according to the matrix, and then proceeding to step 406, by using a color controller for the above The solid color brightness value is corrected. Specifically, the color controller can determine whether the solid color light brightness value is attenuated or abnormal according to the lookup table, and compensate for the attenuation or abnormal brightness value. Finally, in step 407, the corrected solid color light brightness value is transmitted to the light emitting diode driver by the timing controller to drive the plurality of light emitting diodes to display the corrected color, thereby achieving white balance compensation and color correction. purpose.

The above description is a preferred embodiment of the invention. Those skilled in the art should be able to understand the invention and not to limit the scope of the patent claims claimed herein. The scope of patent protection is subject to the scope of the patent application and its equivalent fields. Any modification or refinement made by those skilled in the art without departing from the spirit or scope of the present invention is equivalent to the equivalent change or design made in the spirit of the present disclosure, and should be included in the following patent application scope. Inside.

101. . . Timing controller

102. . . Color controller

103. . . LED driver

104. . . Light-emitting diode

105. . . Gate controller

106. . . Source controller

107. . . LCD panel

108. . . Sensor

201. . . Arithmetic unit

202. . . Light sensor

301. . . First color field

302. . . Second color field

303. . . Third color field

401-407. . . step

Figure 1 depicts a conventional color correction system.

Figure 2 depicts an embodiment of a color correction system of the present invention.

Figure 3 depicts the luminance versus current relationship of a light emitting diode.

Figure 4 depicts an embodiment of the first, second, and third color fields of the present invention.

Figure 5 depicts a flow chart of the invention.

401-407. . . step

Claims (7)

A color correction method for a color sequential display, the method comprising: detecting, by a light sensor, time-sharing values of a first color field, a second color field, and a third color field (R _W , G _W , B _W ); using an arithmetic unit to perform an operation on the detection result of the photo sensor to obtain luminance values (R, G, B) of red, green, and blue; by a color controller Correcting the brightness values of the red, green, and blue solid colors; and transmitting the red, green, and blue solid color brightness values corrected by the color controller to a light emitting diode driver; wherein, the The luminance value of a color field is defined as R _W = R + XG + iB, and the luminance value of the second color field is defined as G _W = mR + G + jB, and the luminance value of the third color field is defined as B _W = nR +yG+B, where, 0 x, y, i, j, m, n < 1, x, y are not 0 at the same time, and i, j are not 0 at the same time, and m and n are not 0 at the same time, and the operation unit is operated by the following matrix : . The color correction method of the color sequential display according to claim 1, further comprising receiving the detection result of the photo sensor by a timing controller, and transmitting the result to the operation unit for calculation. The color correction method of the color sequential display according to claim 1, further comprising driving the plurality of light emitting diodes according to the corrected luminance values of the red, green, and blue solid colors by the LED driver. The color correction method of the color sequential display according to claim 1, wherein the color controller determines whether the luminance values of the red, green, and blue solid colors are attenuated according to a look up table, and The decayed solid color brightness value is compensated. A color correction system for a color sequential display comprises: a light sensor for detecting the brightness values of a first color field, a second color field and a third color field in time (R _W , G _W , B _W); a timing controller, electrically coupled to the light sensor; a computing unit, located in the timing controller, for performing calculation on the detection result of the light sensor, to give red, Green, and blue solid color brightness values (R, G, B); a color controller electrically coupled to the computing unit for correcting the red, green, and blue solid color brightness values; and a light The diode driver is electrically coupled to the timing controller for receiving the corrected luminance values of the red, green, and blue solid colors; wherein the luminance value of the first color field is defined as R _W =R+ xG+iB, the brightness value of the second color field is defined as G _W =mR+G+jB, and the brightness value of the third color field is defined as B _W =nR+yG+B, where 0 x, y, i, j, m, n< 1, x, y are not 0 at the same time, and i and j are not 0 at the same time, and m and n are not 0 at the same time, and the operation unit is operated by the following matrix : . The color correction system of the color sequential display according to claim 5, further comprising a plurality of light emitting diodes coupled to the light emitting diode driver for displaying the corrected red, green, and blue solid color light Brightness value. The color correction system of the color sequential display according to claim 5, wherein the color controller determines whether the luminance values of the red, green, and blue solid colors are attenuated according to a look up table, and The decayed solid color brightness value is compensated.