TWI475555B - Display system and method for controlling display unit - Google Patents

Description

Display system and display unit control method

The invention relates to a display system and a display unit control method, in particular to a display system and a display unit control method with a backlight.

As shown in FIG. 1a, each pixel in a conventional color liquid crystal display is composed of three sub-pixels of a red subpixel 11, a blue sub-pixel 12, and a green sub-pixel 13. composition. In this traditional way, white blocks are displayed, and the three-color sub-pixels in each pixel in the block are turned to the brightest. Otherwise, to display the black block, the three colors in each pixel in the block. Subpixels need to be closed. However, because the color light emitted by the three-color sub-pixel is produced by a color filter, the color filter filters the white light emitted by the back-plate light source to generate color light, which is seen by the viewer. It's only a small part of the light that is seen through, so it's not efficient.

Therefore, as shown in FIG. 1b, an RGBW color liquid crystal display composed of four sub-pixels of red sub-pixel 11, blue sub-pixel 12, green sub-pixel 13 and luminance sub-pixel 14 is developed. Out, and such displays can have good image quality in most of the display states, but can not express high-brightness solid colors. Therefore, how to extract the brightness component from the traditional three primary color image signals, so that the RGBW color liquid crystal display can have the image quality performance that meets most of the image display requirements, and has better power consumption performance, which is the main purpose of developing the case. one.

An object of the present invention is to provide a display system including a display unit and a control signal generator. The display unit has a plurality of display pixels, and any of the display pixels has a first color component. Up to M sub-pixels of a M color component and a mixed color sub-pixel, and the control signal generator includes a brightness extraction unit and a color value generating unit, and the brightness extraction unit includes the first color component value to the Nth color according to The set of color component values of the component values is used to perform a first operation, thereby obtaining a luminance component value representative of the luminance, where N is less than or equal to M. And the color value generating unit receives the color component values and performs the second operation on the brightness component values to respectively generate the first group of color values and the second group of color values, and according to the first group of color values or the second group of colors The control signal is generated by the value, and the control signal is output to the display unit to respectively control the display pixels for display. In this way, the brightness component can be extracted from the traditional three primary color image signals, so that the display system with the mixed color sub-pixel can have the image quality performance meeting most of the image display requirements, and has better power consumption performance.

Another aspect of the present invention is a display unit control method, wherein the display unit has a plurality of display pixels, and any one of the display pixels has a first color component to an Mth color. M sub-pixels of the component and a mixed color sub-pixel, and the control method comprises the steps of: receiving a color component value set; and determining, according to the color component value set, a first color component value to an N-th color component value Performing a first operation to obtain a luminance component value representative of luminance, wherein N is less than or equal to M; receiving the color component values and performing a second operation on the luminance component values to respectively generate a first group of color values and a a second set of color values; and based on the first set of color values or The second set of color values generates the control signal, and the control signal is output to the display unit to respectively control the display pixels for display.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Please refer to FIG. 2 , which is a schematic diagram of the function of the display system developed in the present invention for improving the lack of conventional means, which mainly includes a display unit 2 having a plurality of display pixels (not shown in the figure). For example, a liquid crystal display panel having 1920 ^* 1080 display pixels. And any display pixel 20 of the display pixels has M sub-pixels displaying the first color component to the Mth color component and a mixed color sub-pixel, and the common configuration of M=3 is taken as an example to display The pixel 20 has a first sub-pixel 201, a second sub-pixel 202, a third sub-pixel 203, and a fourth sub-pixel 204 different from the above three colors but mixed with the three colors, respectively. Common examples are red sub-pixels, green sub-pixels, blue sub-pixels, and luminance sub-pixels to enhance or compensate for brightness, such as white sub-pixels or other high-intensity mixed-color sub-pixels. For convenience of explanation, the following description will be made by taking the red sub-pixel, the green sub-pixel, the blue sub-pixel, and the luminance sub-pixel as an example.

The display system of the present invention further includes a control signal generator 21 electrically connected to the display unit 2 for generating a control signal required for controlling the display unit 2. The control signal generator 21 mainly includes a brightness extraction unit 210 and a color value. The generating unit 211, the brightness extracting unit 210 may perform the first operation according to the color component value set S1 including the first color component value to the Nth color component value, thereby obtaining the brightness component value W representing the brightness, where N is less than or equal to M. For example, the red component value R and the green component received from the outside can be selected. The first operation is performed by any one of the value G, the blue component value B, or any two or three color component values, thereby obtaining a color mixture component value representative of the color mixing intensity, and the present example is performed by using the luminance component value W representing the luminance. Description. The color value generating unit 211 receives the color component values and performs the second operation on the luminance component values W to generate a first group of color values CV1 and a second group of color values CV2, respectively, and the control signal generator 21 can The control signal C is generated by selecting one of the first set of color values CV1 or the second set of color values CV2, and the control signal C is output to the display unit 2 for respectively controlling the display pixels for display.

The following implementations of the above-described control signal generator 21 are as follows. For convenience of description, the following embodiments control the first sub-pixel 201, the second sub-pixel 202, and the third sub-pixel 203. And the display of one of the fourth sub-pixels 204 is taken as an example, and the area ratio of the first sub-pixel 201, the second sub-pixel 202, the third sub-pixel 203, and the fourth sub-pixel 204 is 1:1:1:n, the most common is 1:1:1:1, for example, the area ratio of the area of the first subpixel, the second subpixel, and the third subpixel and the fourth subpixel It is 3:1. The combination of the common first subpixel 201, the second subpixel 202, the third subpixel 203, and the fourth subpixel 204 is a red subpixel, a green subpixel, a blue subpixel, and a white sub Pixels, but the actual application is not limited to this, and the area ratio can be any ratio.

Referring again to FIG. 3a, a functional block diagram of a first embodiment of the control signal generator 21 is proposed in the present invention, wherein a gamma correction look-up-table 2100 is used to receive the representative three primary colors. The digital color value data (dRi, dGi, dBi) is further converted into gamma-corrected digital color value data (Ri, Gi, Bi), and then gamma-corrected digital color value data (Ri, Gi) , Bi) takes one to three color components to form The color component value set S1 shown in FIG. The luminance extraction unit 210 performs the first operation using the color component value set S1 to obtain the luminance component value W. The first operation may include the following steps: determining an initial luminance value Wi according to the color component value set S1, and determining the condition that the range of the luminance initial value Wi needs to be limited to the maximum S1 in the color component value set. Between the value and the minimum value, that is, a value is selected from the range between the maximum value and the minimum value among the N color component values as the brightness initial value Wi, and then the brightness initial value Wi is multiplied by 1/(1). +n) to obtain the luminance component value W.

The color value generating unit 211 is configured to receive the color component values Ri, Gi, Bi and the brightness component value W to perform a second operation, and the second operation may use a multiplier or a subtractor implemented in a hardware or a firmware. And the adder performs a flow chart of the steps shown in FIG. 4: multiplying the color component values Ri, Gi, Bi by a coefficient, the coefficients are substantially the same as n, and then subtracting the luminance component value W A first set of adjusted color values is obtained (step 41), and the first set of adjusted color values and the luminance component values W are combined into the first set of color values CV1 (step 42). In addition, a minimum value selected from the first set of adjusted color values is added to the luminance component value W to obtain an adjusted luminance component value (step 43), and the first set of adjusted color values is further subtracted from the minimum. And obtaining a second set of adjusted color values (step 44), and combining the second set of adjusted color values and the adjusted brightness component values into the second set of color values CV2 (step 45), thereby generating a first a set of color values CV1 and a second set of color values CV2, and the control signal C can be generated from the first set of color values CV1 or the second set of color values CV2 (step 46), and finally the control The signal C is output to the display unit 2 to respectively control the display pixels for display (step 47).

As can be seen from the above description, in this case, at least two sets of color values can be obtained, that is, the brightness component value W of the control brightness sub-pixel 204 can be various. When the mode is selected, and the group of color values of the larger value of the brightness component value W is selected from the plurality of sets of color values for display, lower power consumption can be obtained with respect to other group color values, and therefore, The consumption is premised, and the set of color values of the larger of the luminance component values can be selected for display. The above-mentioned coefficient n can be broadly defined as the ratio of the luminance component value W to the average value of the color component value set, but the common red sub-pixel, the green sub-pixel, the blue sub-pixel, and the luminance sub-pixel For example, the area ratio is 1:1:1:n, and the above coefficient is n/((1+1+1)/3)=n. Then, the multiplexer 212 can be used to receive the first set of color values CV1 and the second set of color values CV2 for selecting one set of color values, and electrically connected to the multiplexer 212 and the display unit. The two conversion circuits 213 are configured to convert the first group of color values CV1 or the second group of color values CV2 outputted by the multiplexer 212 into the control signal C to output to the display unit 2 to respectively control the displays. The pixels are displayed.

However, using a larger value of the luminance component W can result in lower power consumption, but it is possible to calculate other components in the color value to be negative and cannot be displayed on the display, so a negative number detection mechanism is required. It can also be done in a hard or tough manner. When the negative number detection mechanism finds that other components in the color value are negative (which can be determined by the minimum value of the first set of adjusted color values being less than a predetermined value "0"), the previously subtracted value is added back. And get a set of color values that are properly achievable. Taking the first group of color values CV1 and the second group of color values CV2 as an example, if any of the second group of color values CV2 is negative, the subtracted value (for example, the first group of adjusted color values mentioned above) The selected minimum value is added back, and in this case it is just restored to the first set of color values CV1. Therefore, the result of the negative number detection mechanism can be used to control the multiplexer 212, and the color value component here can use the two's complement number as a digital system to facilitate the expression of positive and negative numbers.

As for the backlight power controller 214, a backlight power control signal BLC may be generated according to the first color value CV1 output by the multiplexer 212 or the maximum of the plurality of color value components of the second color value CV. Output to the display unit 2. In this way, the display unit 2 can continue to operate at a minimum backlight brightness that can meet the display requirements, thereby achieving power saving.

In addition, since a complete picture of the display contains many pixels, all the pixels in the picture are included to select the maximum value, and the best contrast can be obtained under the consideration of power saving. However, it is also possible to determine the maximum value by simply setting a pixel of a certain effective pixel ratio (for example, 90%) by setting, and reducing the number of samples without affecting the picture quality (PQ).

In addition, the condition for determining the initial luminance value Wi according to the color component value set S1 in the first operation may be changed according to requirements, for example, if the maximum value in the luminance component value W is used for display, it is likely that A dot noise is generated on the display unit 2, so that the condition for determining the initial luminance value Wi can be set to an arbitrary value between the maximum value and the minimum value in the color component value set S1, thereby avoiding the display unit 2. Pixel noise is generated, and the preferred value of the brightness initial value Wi can be selected as the square of the minimum value to avoid dot noise.

In addition to being applicable to the above four seed pixel display unit 2, the present invention can also be applied to display units of only three sub-pixels of red sub-pixel, green sub-pixel, and blue sub-pixel, as long as N is set. It is 0 and the output of the luminance component value W is ignored, so that it can be directly transferred to the display unit having only three primary color sub-pixels. In addition, as shown in FIG. 3b, it is a functional block diagram of the second embodiment of the control signal generator 21, which mainly uses the backlight source in the display unit 3 from a common white light cold cathode tube (CCFL) and When the white light-emitting diode is changed into a three-primary light-emitting diode, the backlight power supply in this example The controller 314 is configured to generate corresponding RGB backlight power control signals BLCR and BLCG according to the first maximum color value CV1 output by the multiplexer 212 or the individual maximum values of the RGB three primary color components of the second color value CV. The BLCB is output to the display unit 3 for respectively controlling the brightness of the three primary color light-emitting diodes, thereby achieving the effect of the Dynamic Contrast Ratio (DCR). In this way, if the wavelength band of the RGB three primary color light-emitting diodes in the display unit 3 matches the frequency band of the color filter in the display unit 3, the embodiment can keep the RGB three primary color light-emitting diodes continuously operating in accordance with the display requirements. The minimum brightness of the light, in order to achieve power saving effect.

Furthermore, if the color filter in the display unit 3 is removed, and the three primary color data in the control signal C and the BLCR, BLCG, and BLCB signals in the RGB backlight power control signal are changed to sequential output, the light extraction efficiency can be greatly increased. And it also helps to reduce power consumption.

Alternatively, the RGBW system can be changed to other color space systems. For example, when the blue signal is independent of the color mixing process, the RGBY (yellow, YELLOW) system can be realized, and when the red signal is independent of the color mixing process, the RGBC (green) is realized. , CYAN) system, and when the green signal is independent of the color mixing process, the RGBM (Magenta, MAGENTA) system can be realized. The structure of the case can also be directly transferred without major modification, so the structure of the case has considerable application flexibility. .

Referring to FIG. 3c, it is a functional block diagram of the third embodiment of the control signal generator 21, wherein the first determiner 41 and the second determiner 42 are respectively used to set the color component values S1. The maximum value MAX1 of (Ri, Gi, Bi) and the maximum value MAX2 of the color value component of the color value CV output from the multiplexer 212 are taken out, and then the coefficient generator 43 is used to divide the two to obtain a coefficient (MAX1/MAX2). And multiplying the color value CV output from the multiplexer 212 by the multiplier 44 by the coefficient (MAX1/MAX2) and then outputting it to the turn The circuit 213 is replaced with the backlight power controller 214, so that the algorithm for emphasizing contrast can be integrated into the architecture of the present invention. After multiplying the coefficient (MAX1/MAX2), the maximum value of each picture can be obtained. Dynamic Contrast Ratio (DCR). Moreover, in order to switch between different contrast preferred color gamuts, the formula may be changed as long as the condition of determining the initial brightness value Wi in the luminance extraction unit 210 is changed. In addition, if the multiplied coefficient is changed from (MAX1/MAX2) back to 1, the original color preference mode can be switched back. Furthermore, FIG. 3b and FIG. 3c can also be integrated to complete different color space systems that can balance the preferred color gamut.

In addition, the present invention can also display the unit control method in various display systems, mainly after receiving the color component value set, according to the first color component value to the Nth color component value in the color component value set. a first operation, thereby obtaining a luminance component value representative of the luminance, wherein N is less than or equal to M, and then receiving the color component values and performing the second operation on the luminance component values to respectively generate the first group of color values and the second group of color values, Finally, the control signal is generated according to the first set of color values or the second set of color values, and the control signal is output to the display unit to respectively control the display pixels for display.

In this way, the method and the device of the present invention can extract the brightness (W) or the chrominance (CMY) component from the traditional three primary color image signals, so that the RGRW color liquid crystal display device or other similar flat display, such as a plasma display, Organic light-emitting diode displays or electronic products equipped with various flat-panel displays can have the image quality performance that meets most of the image display requirements, and have better power consumption performance, thereby achieving the purpose of developing the case.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. Scope of protection The scope defined in the patent application is subject to change.

2‧‧‧Display unit

20‧‧‧ Displaying pixels

11‧‧‧Red sub-pixel

13‧‧‧Green sub-pixels

12‧‧‧Blue sub-pixel

14‧‧‧Brightness sub-pixels

201‧‧‧Red sub-pixel

202‧‧‧Green sub-pixels

203‧‧‧Blue sub-pixel

204‧‧‧Brightness subpixel

21‧‧‧Control signal generator

210‧‧‧Brightness extraction unit

211‧‧‧Color value generating unit

2100‧‧‧Gamma Correction Lookup Table

212‧‧‧Multiplexer

213‧‧‧Transition circuit

214‧‧‧Backlight power controller

3‧‧‧Display unit

314‧‧‧Backlight power controller

41‧‧‧First judge

42‧‧‧Second judger

43‧‧‧ coefficient generator

44‧‧‧Multiplier

W‧‧‧Brightness component values

S1‧‧‧ color component value set

C‧‧‧Control signal

CV1‧‧‧ first set of color values

BLC‧‧‧Backlight power control signal

CV2‧‧‧ second set of color values

(dRi, dGi, dBi) ‧ ‧ digital color value data

(Ri, Gi, Bi) ‧ ‧ gamma corrected digital color value data

BLCR, BLCG, BLCB‧‧‧RGB backlight power control signals

FIG. 1a is a schematic diagram of a pixel composed of a red sub-pixel, a blue sub-pixel, and a green sub-pixel in a conventional color liquid crystal display.

FIG. 1b is a schematic diagram of RGBW pixels composed of four sub-pixels of red sub-pixel, blue sub-pixel, green sub-pixel and luma sub-pixel.

Figure 2 is a block diagram showing the function of the display system proposed in the present case.

Figure 3a is a functional block diagram of a first embodiment of a control signal generator in this case.

Figure 3b is a functional block diagram of a second embodiment of the control signal generator.

Fig. 3c is a functional block diagram showing a third embodiment of the control signal generator in the present case.

Figure 4 is a flow chart showing the steps of the display unit control method in the present case.

2‧‧‧Display unit

20‧‧‧ Displaying pixels

201‧‧‧Red sub-pixel

202‧‧‧Green sub-pixels

203‧‧‧Blue sub-pixel

204‧‧‧Brightness subpixel

21‧‧‧Control signal generator

210‧‧‧Brightness extraction unit

211‧‧‧Color value generating unit

S1‧‧‧ color component value set

W‧‧‧Brightness component values

C‧‧‧Control signal

CV1‧‧‧ first set of color values

CV2‧‧‧ second set of color values

Claims (18)

A display system comprising: a display unit having a plurality of display pixels thereon, wherein any one of the display pixels has a display of a first color component to an Mth color component. a pixel and a mixed color sub-pixel; and a control signal generator electrically connected to the display unit for generating a control signal required to control the display unit, the control signal generator comprising: a mixed color extraction unit, Performing a first operation according to a set of color component values including a value of the first color component to a value of the Nth color component, thereby obtaining a mixed color component value representative of the color mixing intensity, wherein N is less than or equal to M; and a color value a generating unit, receiving the color component values and performing a second operation on the color component values to generate a first group of color values and a second group of color values, and according to the first group of color values or the second group of colors Generating the control signal, the control signal is output to the display unit to respectively control the display pixels for display; wherein the mixed color sub-pixel is a luminance sub-pixel, the color mixing unit is a brightness extraction unit, and the color component value is a brightness component value, and any one of the display pixels includes the first color component to the first M sub-pixels of the M color components and the luminance sub-pixel, and the luminance extraction unit performs the first operation according to the color component value set including the first color component value to the N-th color component value And the ratio of the brightness component value to the average value of the color component value set is n, wherein the ratio n is the area of the fourth sub-pixel and the first sub-pixel, the second sub-pixel, and the first The ratio of the average area of the three sub-pixels. The display system of claim 1, wherein the first operation performed by the brightness extraction unit comprises the step of: determining an initial brightness value according to the color component value set, wherein the brightness initial value ranges from the color Between the maximum value and the minimum value in the set of component values; and multiplying the initial value of the luminance by 1/(1+n) to generate the luminance component value. The display system of claim 1, wherein the second operation performed by the color value generating unit comprises the steps of: multiplying the color component values by a coefficient and subtracting the luminance component value to obtain a The first group adjusts the color value; combines the first set of adjusted color values with the brightness component value into the first set of color values; and selects a minimum value from the first set of adjusted color values to add the brightness component value Obtaining an adjusted brightness component value; and subtracting the first set of adjusted color values from the minimum value to obtain a second set of adjusted color values, and combining the second set of adjusted color values with the adjusted brightness component values The second set of color values. The display system of claim 3, wherein the coefficient is a ratio of the luminance component value to an average of the color component value sets. The display system of claim 3, wherein the coefficient is zero. The display system of claim 3, wherein the coefficient is 1. The display system of claim 3, wherein the control signal generator further comprises: a multiplexer receiving the first set of color values and the second set of color values, when the first set of adjusted color values Selecting and outputting the second set of color values when the minimum value selected is less than a predetermined value, and selecting to output the first set of color values when the selected value of the first set of adjusted color values is greater than or equal to the predetermined value And a conversion circuit electrically connecting the multiplexer and the display unit for converting the first set of color values or the second set of color values output by the multiplexer into the control signal output to the display The unit displays the display pixels separately. The display system of claim 7, wherein the control signal generator further comprises a backlight power controller for outputting the first set of color values or the second set of color values according to the multiplexer The maximum value is generated to generate a backlight power control signal output to the display unit. The display system of claim 8, wherein the backlight power controller selects a effective pixel ratio of the display pixels in the display unit, and the display pixels according to the effective pixel ratio Corresponding to the first set of color values or the maximum of the second set of color values to generate the backlight power control signal output to the display unit. A display unit control method, the display unit has a plurality of display pixels, and any one of the display pixels has M sub-pixels displaying a first color component to an M-th color component and Used to display different from the first a color component to one of the Mth color mixed color sub-pixels, and the control method comprises the steps of: receiving a color component value set; according to one of the color component value sets, the first color component value to an Nth color The component value is used to perform a first operation, thereby obtaining a mixed color component value representative of the color mixing intensity, wherein N is less than or equal to M; and performing a second operation according to the color component value and the mixed color component value to respectively generate a first color group And a second set of color values; and generating the control signal according to the first set of color values or the second set of color values, and outputting the control signal to the display unit to respectively control the display pixels for display Wherein the mixed color sub-pixel is a luminance sub-pixel, and the ratio of the luminance component value to the average value of the color component value set is n, wherein the ratio n is the area of the fourth sub-pixel and the first The ratio of the sub-pixel, the second sub-pixel, and the area average of the third sub-pixel. The display unit control method according to claim 10, wherein the first operation comprises the step of: determining an initial brightness value according to the color component value set, wherein the brightness initial value ranges from the color component value set Between the maximum value and the minimum value; and multiplying the initial value of the brightness by 1/(1+n) to generate the brightness component value. The display unit control method according to claim 10, wherein the second operation comprises the steps of: multiplying the color component values by a coefficient and subtracting the luminance component Numerically obtaining a first set of adjusted color values; combining the first set of adjusted color values and the brightness component values into the first set of color values; selecting a minimum value and the brightness from the first set of adjusted color values Adding component values to obtain an adjusted brightness component value; and subtracting the first set of adjusted color values from the minimum value to obtain a second set of adjusted color values, and then adjusting the second set of adjusted color values and the adjustment The post luminance component values are combined into the second set of color values. The display unit control method according to claim 12, wherein the coefficient is a ratio of the brightness component value to the average value of the color component value set. The display unit control method according to claim 12, wherein the coefficient is zero. The display unit control method according to claim 12, wherein the coefficient is 1. The display unit control method of claim 10, comprising the steps of: receiving the first set of color values and the second set of color values, and selecting the minimum value of the first set of adjusted color values is less than a predetermined value, converting the second set of color values into the control signal output to the display unit to respectively control the display pixels for display; and selecting the minimum value of the first set of adjusted color values to be greater than Equal to the pre When the value is fixed, the first set of color values is selected to be converted into the control signal and output to the display unit to respectively control the display pixels for display. The display unit control method of claim 10, further comprising the step of: generating a backlight power control signal output to the display unit according to the first color value or the second color value of the second color value . The display unit control method according to claim 17, further comprising the steps of: selecting a effective pixel ratio of the display pixels in the display unit, and displaying the display according to the effective pixel ratio The first set of color values or the maximum of the second set of color values corresponding to the color to generate the backlight power control signal output to the display unit.