Method for achieving color backlight luminous balance and improving luminous intensity

Abstract

Disclosed in the present invention is a method for achieving color backlight luminous balance and improving luminous intensity. Firstly, on the basis of a red-green-blue light source, a red sub-light source is used for replacing a blue sub-light source to form a red-green-red light source. A same number of red-green-blue light sources and red-green-red light sources are alternately arranged to jointly form a backlight micro-unit, having a ratio of blue sub-light sources: green sub-light sources: red sub-light source of 1: 2: 3. All red, green and blue sub-light sources in each backlight micro-unit are connected in series and independently driven. Finally, a plurality of backlight micro-units is arranged to form a complete color backlight. In the process of achieving color backlight luminous balance, the present method improves the proportion of the drive current for the green and blue sub-light sources, and significantly improves the average drive current and the luminous intensity. By selecting the wavelength of the blue sub-light sources, low blue light of the hardware is achieved. By adjusting the current of the blue sub-light sources, the display color temperature is adjusted by hardware.

Description

A method for achieving color backlight luminescence balance and improving luminous intensity Technical Field

[0001] The present invention relates to the field of liquid crystal display technology, and in particular to a method for achieving color backlight luminescence balance and improving luminous intensity. Background Art

[0002] Conventional color backlighting involves packaging red, green, and blue (RGB) LED chips into full-color LED devices, which are then arranged into a full-array color backlight. These sub-light sources are then mixed in a 2:7:1 ratio of red:green:blue to create a standard white light with a color temperature of 6500K, achieving balanced color backlighting. To achieve this balanced color backlighting, the driving currents flowing through the corresponding red, green, and blue LED chips are typically in a 4:3:1 ratio of red:green:blue. Technical issues

[0003] Because the backlight driver has a fixed maximum drive current limit for each sub-light source channel, under this sub-light source channel maximum drive current limit, in order to achieve color backlight luminescence balance, when the drive current of the red LED chip reaches its maximum, the drive current of the green LED chip does not reach its maximum value, and the drive current of the blue LED chip is even only one-quarter of the maximum drive current limit. Because the drive current of the green LED chip and the blue LED chip does not reach the maximum drive current of the sub-light source, the backlight luminous intensity is lost.

[0004] Conventional white backlight has a continuous luminous spectrum and does not have a low blue light function. It can only use a software low blue light solution that adjusts the blue grayscale level of the image, thereby reducing the display brightness.

[0005] Conventional white backlight does not have the function of adjusting color temperature. The only way to adjust the display color temperature is to use software to adjust the blue grayscale level of the image, which reduces the display brightness. Technical Solutions

[0006] The present invention aims to provide a method for achieving balanced color backlighting and improving luminous intensity. This method changes the ratio of sub-light sources. Compared to conventional color backlights, this method increases the average drive current of the sub-light sources when achieving balanced color backlighting, targeting standard white light with a color temperature of 6500K, while maintaining the same maximum drive current limit for the sub-light sources. This achieves balanced luminous intensity and improves luminous intensity.

[0007] The technical solution adopted by the present invention is as follows: (1) On the basis of conventional red, green and blue light sources, a red sub-light source is used to replace a blue sub-light source to form a red, green and red light source. (2) The same number of conventional red, green and blue light sources and red, green and red light sources are alternately arranged to form a backlight micro-unit, wherein the ratio of blue sub-light source: green sub-light source: red sub-light source is 1:2:3. (3) By selecting the wavelength of the blue sub-light source, a hardware low blue light solution is realized. (4) All red sub-light sources in each backlight micro-unit are connected in series and driven separately, all green sub-light sources in the backlight micro-unit are connected in series and driven separately, and all blue sub-light sources in the backlight micro-unit are connected in series and driven separately. (5) Several backlight micro-units are arranged to form a complete color backlight. (6) In the process of achieving color backlight luminescence balance, when the target is a standard white light with a color temperature of 6500K, the driving current ratio of the green and blue sub-light sources is increased, and the average driving current and luminous intensity are significantly improved. (7) By simply increasing the current of the blue sub-light source, the luminous intensity of the blue sub-light source can be increased, and the display color temperature can be adjusted by hardware. Beneficial effects

[0008] The technical effect of the present invention is that by changing the ratio of the number of sub-light sources, the average drive current and luminous intensity can be significantly increased under the same sub-light source maximum drive current limit. By selecting the wavelength of the blue sub-light source, a hardware low-blue light solution can be implemented, which can increase the display brightness compared to a software low-blue light solution that adjusts the blue grayscale level of the image. By simply adjusting the current of the blue sub-light source, the luminous intensity of the blue sub-light source can be increased, and the display color temperature can be adjusted by hardware, which can increase the display brightness compared to a software low-blue light solution that adjusts the blue grayscale level of the image. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying figure is a schematic diagram of a backlight micro unit composed of 2 red, green and blue light sources and 2 red, green and red light sources, wherein the number ratio of blue sub-light source: green sub-light source: red sub-light source is 1:2:3.

[0010] Figure 1: R+: positive pole of the power supply connected in series by 6 red sub-light sources; G+: positive pole of the power supply connected in series by 4 green sub-light sources; B+: positive pole of the power supply connected in series by 2 blue sub-light sources; R-: negative pole of the power supply connected in series by 6 red sub-light sources; G-: negative pole of the power supply connected in series by 4 green sub-light sources; B-: negative pole of the power supply connected in series by 2 blue sub-light sources; 1: conventional red, green and blue light source; 2: red, green and red light source. Best Mode for Carrying Out the Invention

[0011] Example 1:

[0012] Embodiment 1 of the present invention provides a liquid crystal display method based on the principles of optical isolation and partitioning and temporal color mixing, which is described by taking a specific implementation as an example.

[0013] (1) When selecting a 1600*1200 resolution, high refresh rate, color filter-free LCD panel, a reflective cup array plate with 25 horizontal and 19 vertical reflective cups is molded out of an iron-nickel-cobalt Kovar alloy sheet with a thermal expansion coefficient close to that of the LCD panel. The reflective cup array plate is mounted on a color LED backlight array plate. Each individual rectangular reflective cup in the reflective cup array plate covers a display area of ​​64*64 pixels. The color LED backlight array plate is configured using a method for achieving color backlight luminescence balance and improving luminous intensity, which is implemented as step A.

[0014] (2) Optical films such as diffusion films, BEF prism films, and DBEF birefringent films with light-homogenizing and brightness-enhancing effects are installed on the molded reflective cup array board. Finally, a high-refresh rate, color-filter-free liquid crystal panel is installed on the optical film. The reflective cup array board can be used to partition the liquid crystal display area, and any partition is optically isolated from the other partitions. By using the optical isolation partitioning method, the color and brightness of the color light source in the partition can be independently adjusted without affecting other adjacent partitions.

[0015] (3) By collecting the VSYNC frame synchronization signal or the DE display data enable signal generated by the display video signal, the backlight control counter is triggered to record the video signal CLK clock cycle, which continues until the first row scan line of the next frame starts to update the display. The delay time is calculated based on the total number of video signal CLK clocks recorded during this period, the row scan line position is determined, and the color and brightness of the color light source in the corresponding optical isolation partition are updated.

[0016] (4) For the color backlight source and the high refresh rate color filter-free liquid crystal panel in the optical isolation partition, an energy-saving display method based on the synchronous adjustment of the color backlight and grayscale pattern of the optical isolation partition is used to perform energy-saving optimization, which is implemented as step B.

[0017] (5) A display method of pre-fill light subtraction image synthesis based on the principle of time color mixing is used as step C to complete the final color picture display. Modes for Carrying Out the Invention

[0018] Example 2:

[0019] A second embodiment of the present invention provides a method for achieving balanced color backlighting and increasing luminous intensity. This method can be applied to the liquid crystal display method based on optical isolation, zoning, and temporal color mixing principles provided in the first embodiment, as a specific implementation of step A. Furthermore, this method for achieving balanced color backlighting and increasing luminous intensity can also be performed independently to increase the driving current share of the green and blue sub-light sources, significantly improving the average driving current and luminous intensity of the sub-light sources. This embodiment uses the independent implementation as an example for illustration.

[0020] (1) Select a 3030 packaged RGB-LED lamp as the red, green, and blue light source, and replace the blue LED chip with a red LED chip as the red, green, and red light source. The maximum current limit for each chip is 20mA. When the red chip is supplied with 18mA, the green chip with 13.5mA, and the blue chip with 4.5mA, the RGB-LED lamp emits white light with a color temperature of 6500K. The average current per chip is 12mA, and the average luminous intensity of each LED lamp is 2.85cd.

[0021] (2) The backlight micro unit is composed of two red, green and blue light sources and two red, green and red light sources arranged alternately, where the ratio of blue: green: red LED chips is 1:2:3.

[0022] (3) Hardware low blue light is achieved by using blue LED chips with a main wavelength of 460nm.

[0023] (4) All red sub-light sources in the backlight micro-unit are connected in series and driven individually, all green sub-light sources in the backlight micro-unit are connected in series and driven individually, and all blue sub-light sources in the backlight micro-unit are connected in series and driven individually.

[0024] (5) Use several backlight micro units to arrange into a complete color backlight.

[0025] (6) In the process of achieving color backlight luminescence balance, when the target is standard white light with a color temperature of 6500K, according to the method of using all red, green and blue light sources, the solution of 4 RGB-LED lights in a single backlight micro-unit has an average current of 12mA per chip and a luminous intensity of 11.4cd per backlight micro-unit; using the solution of 2 red, green and blue light sources and 2 red, green and red light sources in a single backlight micro-unit, the red chip has an 18mA current, the green chip has a 20mA current, and the blue chip has a 13.5mA current, with an average current of 18mA per chip and a luminous intensity of 17.1cd per backlight micro-unit; experiments have shown that using this method to achieve color backlight luminescence balance and improve luminous intensity can increase the average current of the sub-light source by 50% under the same maximum driving current limit of the sub-light source, thereby increasing the luminous intensity by 50%. Example

[0026] A third embodiment of the present invention provides an energy-saving display method for synchronously adjusting a color-separated backlight and a grayscale pattern based on optically isolated zoning. This method can be applied to the liquid crystal display method based on optically isolated zoning and temporal color mixing principles provided in the first embodiment, as a specific implementation of step B. Furthermore, this energy-saving display method for synchronously adjusting a color-separated backlight and a grayscale pattern based on optically isolated zoning can also be performed independently. By synchronously adjusting the color-separated backlight and the grayscale pattern, energy savings can be achieved while maintaining the same display. This embodiment uses the independent method as an example for illustration.

[0027] (1) When selecting a 1600*1200 resolution LCD panel, a reflective cup array plate with 25 horizontal and 19 vertical reflective cups is molded out of an iron-nickel-cobalt Kovar alloy sheet with a thermal expansion coefficient close to that of the LCD panel. The reflective cup array plate is then mounted on a color LED backlight array panel. Each individual rectangular reflective cup in the reflective cup array plate covers a display area of ​​64*64 pixels. Then, optical films such as a diffusion film, a BEF prism sheet, and a DBEF birefringent sheet with light-homogenizing and brightening effects are mounted on the molded reflective cup array plate. Finally, the LCD panel is mounted on the optical film. The reflective cup array plate can be used to partition the LCD display area, and any partition is optically isolated from the other partitions. By using the optical isolation partitioning method, the color and brightness of the color light source in the partition can be independently adjusted without affecting other adjacent partitions.

[0028] (2) The main controller inside the display decodes the video signal sent by the host computer to the display and separates the 64*64 pixel color display image corresponding to each reflector cup in the next frame. It then searches for the maximum grayscale level of the sub-pixel corresponding to the sub-light source within the optical isolation partition. The maximum grayscale level of the sub-pixel corresponding to the red sub-light source is 127; the maximum grayscale level of the sub-pixel corresponding to the green sub-light source is 63; and the maximum grayscale level of the sub-pixel corresponding to the blue sub-light source is 192.

[0029] (3) Because the grayscale range displayed by the LCD panel is 0-255, the upper limit of the grayscale range of the LCD panel is divided by the maximum value of the grayscale levels of the three sub-pixels, and the magnification corresponding to red is 2 times, the magnification corresponding to green is 4 times, and the magnification corresponding to blue is 1.33 times.

[0030] (4) The grayscale levels of all sub-pixels corresponding to the red sub-light source in the optical isolation partition are increased to 2 times, and the luminous intensity of the red sub-light source is reduced to 1 / 2. The 64*64 grayscale pattern with a grayscale level of 0-127 is illuminated by a 100% brightness backlight. The display effect is the same as that of the 64*64 grayscale pattern with a grayscale level of 0-255 using a 50% brightness backlight. Therefore, by synchronously adjusting the color separation backlight and the grayscale pattern, a 50% energy saving effect can be achieved without changing the display.

[0031] (5) Similarly, the grayscale levels of all sub-pixels corresponding to the green sub-light source in the optical isolation partition are increased to 4 times, and the luminous intensity of the green sub-light source is reduced to 1 / 4. A 100% brightness backlight is used to illuminate a 64*64 grayscale pattern with a grayscale level of 0-63. The display effect is the same as that of a 25% brightness backlight to illuminate a 64*64 grayscale pattern with a grayscale level of 0-255. By synchronously adjusting the color separation backlight and the grayscale pattern, a 75% energy saving effect can be achieved without changing the display.

[0032] (6) Similarly, the grayscale levels of all sub-pixels corresponding to the blue sub-light source in the optical isolation partition are increased to 1.33 times, and the luminous intensity of the blue sub-light source is reduced to 75%. The 64*64 grayscale pattern with a grayscale level of 0-192 is illuminated by a 100% brightness backlight. The display effect is the same as that of the 64*64 grayscale pattern with a grayscale level of 0-255 using a 75% brightness backlight. By synchronously adjusting the color separation backlight and the grayscale pattern, a 25% energy saving effect is achieved without changing the display.

[0033] Taking various situations into consideration, the use of this energy-saving display method based on optical isolation partitioning, color backlight and grayscale pattern synchronous adjustment can save an average of about 50% energy while keeping the display unchanged. Example

[0034] A fourth embodiment of the present invention provides a display method for pre-fill light subtraction frame image synthesis based on the principle of temporal color mixing. This method can be applied to the liquid crystal display method based on optical isolation and zoning and temporal color mixing provided in the first embodiment, as a specific implementation of step C. Furthermore, this display method for pre-fill light subtraction frame image synthesis based on the principle of temporal color mixing can also be performed independently, reducing the original color image reproduction method using the principle of temporal color mixing, which requires a fixed, continuous display of three subframes in a cycle, to only one or two frames. This embodiment uses the independent method as an example for illustration.

[0035] (1) The main controller inside the display decodes the video signal sent by the host computer to the display and separates the next frame of 64*64 pixel color display image. The image content is the image of a golden sun with purple eyes.

[0036] (2) Decompose a single color image into three monochrome images of red, green and blue. The three monochrome images are rearranged in a fixed order of green-red-blue according to their influence on the color image.

[0037] (3) The three monochrome images are further decomposed into a grayscale pattern in the shape of a sun illuminated by green light, a grayscale pattern in the shape of a sun with eyes illuminated by red light, and a grayscale pattern in the shape of an eye illuminated by blue light.

[0038] (4) Using the pre-fill light frame-reduction image synthesis method of the present invention, in the first subframe of the current display cycle, 100% green light is used to illuminate the sun-shaped grayscale pattern, and the entire green monochrome image is displayed. At the same time, 100% red light is used for pre-fill light, illuminating the sun-shaped grayscale pattern, and partially displaying the red monochrome image. At the same time, the calculation results show that the sun-shaped grayscale pattern has nothing to do with blue, and the blue light brightness is 0 and no pre-fill light is performed. Assuming that the image content is a golden sun image, to display the golden sun, it is only necessary to illuminate the sun-shaped grayscale pattern with (green light + red light), and the original golden sun image can be reproduced with only one subframe.

[0039] (5) Using the pre-fill light and frame-subtraction image synthesis method of the present invention, in the second subframe of the current display cycle, 100% red light is used to illuminate the eye-shaped grayscale pattern. Together with the sun-shaped grayscale pattern already displayed in the first subframe, the red monochrome image is fully displayed. At the same time, 100% blue light is used for pre-fill light to illuminate the eye-shaped grayscale pattern, displaying a blue monochrome image. The first subframe already displays a golden sun. To further display a golden sun with purple eyes, it is only necessary to use (red light + blue light) to illuminate the eye-shaped grayscale pattern in the second subframe. The original golden sun image with purple eyes can be reproduced using only two subframes. Industrial Applicability

[0040] By varying the ratio of sub-light sources of different colors, this invention significantly improves average drive current and luminous intensity, while maintaining the same maximum drive current limit. By selecting the wavelength of the blue sub-light source, a hardware-based low-blue-light solution is implemented, which increases display brightness compared to software-based low-blue-light solutions that adjust the image's blue grayscale. Simply adjusting the current of the blue sub-light source increases the luminous intensity of the blue sub-light source, enabling hardware-adjustable display color temperature, which increases display brightness compared to software-based solutions that adjust the image's blue grayscale. Sequence Listing Free Content

[0041] Unordered list.

Claims

1. A method for achieving color backlight luminescence balance and improving luminous intensity, characterized in that: The method comprises the following steps: First, on the basis of the conventional red, green and blue light source, the blue sub-light source is replaced by the red sub-light source to form a red, green and red light source. Then the same number of conventional red, green and blue light sources and red, green and red light sources are arranged alternately to form a backlight micro-unit, where the number ratio of blue sub-light source: green sub-light source: red sub-light source is 1:2:

3. Finally, several backlight micro-units are arranged into a complete color backlight. Compared with conventional color backlight, under the same maximum driving current limit of sub-light sources, by changing the number ratio of sub-light sources, the average driving current of sub-light sources is increased, and the light emission balance and light intensity are improved.

2. The method according to claim 1, characterized in that The red, green, blue light source and the red, green, red light source may be packaged into a device or not.

3. The method according to claim 1, characterized in that The red, green and blue light source and the red, green and red light source can use other color sub-light sources, such as orange sub-light source, to replace the red sub-light source.

4. The method according to claim 1, characterized in that: All red sub-light sources in the backlight micro-unit are connected in series and driven individually, all green sub-light sources in the backlight micro-unit are connected in series and driven individually, and all blue sub-light sources in the backlight micro-unit are connected in series and driven individually.

5. The method according to claim 1, characterized in that The ratio of sub-light sources in the backlight micro-unit may be 1:2:3 for blue sub-light source: green sub-light source: red sub-light source, or other ratios, such as 1:4:6 for blue sub-light source: green sub-light source: red sub-light source.

6. The method according to claim 1, characterized in that By selecting the wavelength of the blue sub-light source, a hardware low blue light solution is implemented. Compared with the software low blue light solution that adjusts the blue grayscale level of the image, the display brightness can be increased.

7. The method according to claim 1, characterized in that By simply adjusting the current of the blue sub-light source, the luminous intensity of the blue sub-light source can be increased, and the display color temperature can be adjusted by hardware. Compared with adjusting the display color temperature by software to adjust the blue grayscale level of the image, the display brightness can be increased.

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