Backlight control method and apparatus

Abstract

The application provides a backlight control method and device, and belongs to the technical field of display. The backlight control method is applied to a backlight source, the backlight source comprises a plurality of backlight sub-zones, the plurality of backlight sub-zones are arranged in an array, and the backlight control method comprises the following steps: calculating the maximum backlight sum of all the backlight sub-zones; determining a proportion parameter according to the maximum backlight sum and the proportion of a current frame display window in the whole display area; determining a weight coefficient according to the maximum backlight sum and the proportion parameter; adjusting the initial backlight value of each backlight sub-zone according to the weight coefficient to obtain the backlight value of each backlight sub-zone, and driving each backlight sub-zone to emit light according to the backlight value. The technical scheme of the application can improve the local area brightness of a display picture and improve the contrast of the display picture.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a backlight control method and apparatus. Background Technology

[0002] Currently, backlighting is the biggest power consumer in LCD displays, leading to the development of Mini LED (direct-lit) products. Several Mini LEDs are arranged on a backlight panel, and through a specific circuit design, independent backlight zone control can be achieved. The brightness of different areas can be dynamically adjusted according to the content of the upper LCD screen. With the enhancement of controller computing power and technological advancements, local dimming has been proposed. By dimming the backlight in the darker areas of the displayed image and compensating accordingly in the display control, the same display effect as full-brightness backlighting can be achieved, reducing backlight power consumption and improving image contrast. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a backlight control method and device that can improve the brightness of local areas of the display screen and enhance the contrast of the display screen.

[0004] To address the aforementioned technical problems, embodiments of the present invention provide the following technical solutions:

[0005] A backlight control method is applied to a backlight source, the backlight source comprising multiple backlight zones arranged in an array, the backlight control method comprising:

[0006] Calculate the maximum backlight sum for all said backlight zones;

[0007] The proportional parameters are determined based on the maximum backlight and the proportion of the current frame display window to the total display area.

[0008] The weighting coefficients are determined based on the maximum backlight and the proportional parameters.

[0009] The initial backlight value of each backlight zone is adjusted according to the weighting coefficient to obtain the backlight value of each backlight zone, and each backlight zone is driven to emit light according to the backlight value.

[0010] In some embodiments, the maximum backlight is determined by the number of backlight zones and the maximum backlight value of the backlight zones.

[0011] In some embodiments, the weighting coefficient PK_W is calculated using the following formula:

[0012] PK_W = 2 53 / (Sum Total -TH) 2

[0013] Among them, Sum Total TH represents the maximum backlight intensity, and TH represents the scaling parameter.

[0014] In some embodiments, the method further includes:

[0015] Calculate the backlight sum of all backlight zones in the current frame;

[0016] The step of adjusting the initial backlight value of each backlight zone according to the weighting coefficient includes:

[0017] When the weighting coefficient is not 0 and the backlight sum is greater than the ratio parameter, the initial backlight value of each backlight zone is adjusted according to the weighting coefficient, the maximum backlight sum, and the backlight sum.

[0018] In some embodiments, the method further includes:

[0019] When the weighting coefficient is 0 or the backlight sum is less than the proportional parameter, the initial backlight value of the backlight zone is adjusted using the following formula:

[0020] BL Peak (i,j)=BL in (i,j)×2 N ;

[0021] Among them, BL Peak (i,j) represents the backlight value of the backlight zone in the i-th row and j-th column, BL in (i,j) represents the initial backlight value of the backlight partition in the i-th row and j-th column, N = AB, where A is the number of bits of the driving data that drives the backlight partition to emit light, and B is the number of bits of the initial backlight value.

[0022] In some embodiments, adjusting the initial backlight value of each backlight zone according to the weighting coefficient, the maximum backlight sum, and the backlight sum includes:

[0023] The initial backlight value of the backlight zone is adjusted using the following formula:

[0024]

[0025] Among them, BL Peak (i,j) represents the backlight value of the backlight zone in the i-th row and j-th column, BL in (i,j) represents the initial backlight value of the backlight zone in the i-th row and j-th column, Sum Total For the maximum backlight and Sum BL For the backlight and, PK W The weighting coefficient is denoted as .

[0026] In some embodiments, driving each of the backlight zones to emit light according to the backlight value includes:

[0027] The backlight zones are driven to emit light in the next frame based on the backlight value.

[0028] An embodiment of the present invention also provides a backlight control device applied to a backlight source, the backlight source including multiple backlight zones, the multiple backlight zones being arranged in an array, the backlight control device including:

[0029] The first calculation module is used to calculate the maximum backlight sum of all said backlight zones;

[0030] The second calculation module is used to determine the ratio parameter based on the maximum backlight and the ratio of the current frame display window to the total display area.

[0031] The third calculation module is used to determine the weighting coefficients based on the maximum backlight and the proportional parameters.

[0032] The processing module is used to adjust the initial backlight value of each backlight zone according to the weighting coefficient to obtain the backlight value of each backlight zone, and drive each backlight zone to emit light according to the backlight value.

[0033] An embodiment of the present invention also provides a backlight control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the program, it implements the backlight control method as described above.

[0034] Embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the backlight control method as described above.

[0035] The embodiments of the present invention have the following beneficial effects:

[0036] In the above scheme, a proportional parameter is obtained based on the maximum backlight and the proportion of the current frame display window to the total display area. A weighting coefficient is determined based on the maximum backlight and the proportional parameter. The initial backlight value of the backlight partition is adjusted according to the weighting coefficient to obtain the backlight value of each backlight partition. This embodiment can adjust the backlight brightness according to the proportion of the current frame display window to the total display area, which can improve the brightness of local areas of the display screen, expand the brightness range of the display product, increase the peak brightness of the display product, and thus improve the screen contrast. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of local dynamic dimming;

[0038] Figure 2 This is a diagram illustrating users' brightness requirements for display products.

[0039] Figure 3 This is a diagram showing the comparison of display brightness when the white window occupies different proportions of the total display area.

[0040] Figure 4 This is a schematic diagram showing the brightness of each grayscale level after adjusting the initial backlight value using weighting coefficients.

[0041] Figure 5 This is a schematic flowchart of the backlight control method according to an embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the backlight control device according to an embodiment of the present invention. Detailed Implementation

[0043] To make the technical problems, technical solutions and advantages of the embodiments of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0044] A schematic diagram of local dynamic dimming is shown below. Figure 1 As shown, the local dynamic dimming algorithm can change the backlight brightness and the opening and closing degree of the liquid crystal in real time according to the content of the displayed image. The brightness of the backlight affects the effect of the liquid crystal display.

[0045] This invention provides a backlight control method and apparatus that can improve the brightness of local areas of the displayed image and enhance the contrast of the displayed image.

[0046] In display product design and display industry standards, there is a desire for display products to achieve higher contrast ratios. For example, relevant technical specifications stipulate that... Figure 2 As shown, the brightness of a full-screen white image is 900 nits, and the brightness of a 10% white window is 1400 nits. This means that the proportion of the white window to the total display area affects the brightness of the white window. Furthermore, for most monitors, brightness is positively correlated with the current input to the backlight LEDs, and the current input to the backlight LEDs is positively correlated with the monitor's power consumption. Therefore, backlight brightness and monitor power consumption are positively correlated. For solid color images, displaying a full-screen white image corresponds to the monitor's maximum power consumption. To balance high contrast and low power consumption, the backlight brightness can be adjusted according to the proportion of the white window to the total display area, such as... Figure 3As shown, S1 represents the normal backlight brightness, and S2 represents the adjusted backlight brightness. The horizontal axis represents the proportion of the white window to the entire display area, and the vertical axis represents the display brightness in nits. It can be seen that the proportion of the white window to the entire display area affects the display brightness of the white window. When the proportion of the white window to the entire display area is less than 10%, the display brightness of the white window is 2000 nits; when the proportion of the white window to the entire display area is 100%, the display brightness of the white window is 1000 nits; when the proportion of the white window to the entire display area is between 10% and 100%, the display brightness of the white window is between 1000 and 2000 nits. Moreover, as the proportion of the white window to the entire display area increases, the display brightness of the white window decreases. This can be seen as adjusting the initial backlight value by multiplying the backlight value of each backlight zone by a weighting coefficient, with the weighting coefficient ranging from 1 to 0.5.

[0047] After adjusting the initial backlight value using weighting coefficients, the brightness diagrams for each grayscale level are as follows: Figure 4 As shown, S3 represents the initial display brightness of the display product, and S4 represents the adjusted display brightness of the display product. The horizontal axis represents the grayscale value, and the vertical axis represents the brightness value, with the unit being nits.

[0048] This invention provides a backlight control method applied to a backlight source, wherein the backlight source includes multiple backlight zones, and the multiple backlight zones are arranged in an array, such as... Figure 5 As shown, the backlight control method includes:

[0049] Step 101: Calculate the maximum backlight sum for all said backlight zones;

[0050] In this embodiment, the maximum backlight is determined by the number of backlight zones and the maximum backlight value of the backlight zones.

[0051] Specifically, the following parameters can be used to calculate the maximum backlight and Sum for all backlight zones. Total :

[0052] Sum Total =BL max *Block V *Block H

[0053] BL max This represents the maximum backlight value for a specific number of bits, for example, when the backlight value is 8 bits of data. max When the backlight value is 255 and the data is 10-bit, the BL value is 255. max When the backlight value is 1023, and the data is 13-bit, the BL value is 1023. max 8191; BlockV Indicates the number of backlight partitions in the column direction, Block H This indicates the number of backlight zones in the horizontal direction. The maximum backlight and Sum calculated in this embodiment... Total It can be applied to display products of different specifications, including display products with different backlight bit values ​​and display products with different backlight zones.

[0054] Step 102: Determine the proportion parameter based on the maximum backlight and the proportion of the current frame display window to the total display area;

[0055] Specifically, the proportional parameter TH can be calculated using the following formula:

[0056] TH = Sum Total *C%

[0057] C% represents the proportion of the current frame's display window to the total display area. The value of C can be 10, 20, etc. This embodiment can calculate the corresponding proportion parameter when the proportion of the display window to the total display area varies.

[0058] Step 103: Determine the weighting coefficients based on the maximum backlight and the scaling parameters;

[0059] Specifically, the weighting coefficient PK_W can be calculated using the following formula:

[0060] PK_W = 2 53 / (Sum Total -TH) 2

[0061] Among them, Sum Total Here, TH represents the maximum backlight value, and TH represents the proportional parameter. The weighting coefficients calculated in this embodiment can be applied to display products of different specifications, including display products with different backlight bit values ​​and display products with different backlight partition numbers.

[0062] Step 104: Adjust the initial backlight value of each backlight zone according to the weighting coefficient to obtain the backlight value of each backlight zone, and drive each backlight zone to emit light according to the backlight value.

[0063] Specifically, the backlight sum of all backlight partitions in the current frame can be calculated. When the weight coefficient is not 0 and the backlight sum is greater than the ratio parameter, the initial backlight value of each backlight partition is adjusted according to the weight coefficient, the maximum backlight sum, and the backlight sum.

[0064] The backlight and Sum of all backlight zones in the current frame can be calculated using the following formula. BL :

[0065]

[0066] Among them, BL in (i,j) represents the initial backlight value of the backlight partition in the i-th row and j-th column.

[0067] When the weighting coefficient is not 0 and the backlight sum is greater than the proportional parameter, the initial backlight value of the backlight zone can be adjusted using the following formula:

[0068]

[0069] Among them, BL Peak (i,j) represents the adjusted backlight value of the backlight zone in the i-th row and j-th column. The backlight value adjustment scheme in this embodiment can be applied to display products of different specifications, including display products with different numbers of bits for backlight value and display products with different numbers of backlight zones.

[0070] Additionally, when the weighting coefficient is 0 or the backlight sum is less than the proportional parameter, the initial backlight value of the backlight zone can be adjusted using the following formula:

[0071] BL Peak (i,j)=BL in (i,j)×2 N ;

[0072] Among them, BL Peak (i,j) represents the backlight value of the backlight zone in the i-th row and j-th column, BL in (i,j) represents the initial backlight value of the backlight partition in the i-th row and j-th column, N = AB, where A is the number of bits of the driving data that drives the backlight partition to emit light, and B is the number of bits of the initial backlight value.

[0073] In this embodiment, when the weighting coefficient is 0 or the backlight sum is less than the proportional parameter, the initial backlight value is not adjusted using the weighting coefficient, and the BL... in (i,j) multiplied by 2 N To match the specifications of display products, backlight values ​​are padded with zeros at low bits, such as BL. in (i,j) is 10-bit data, while driving the backlight requires 13-bit data, so N=3; for example, BL in (i,j) is 8 bits of data, while driving the backlight requires 13 bits of data, so N=5.

[0074] In this embodiment, a proportional parameter is obtained based on the maximum backlight and the proportion of the current frame's display window to the total display area. A weighting coefficient is then determined based on the maximum backlight and the proportional parameter. The initial backlight value of each backlight partition is adjusted according to this weighting coefficient, resulting in the backlight value for each partition. This embodiment can adjust the backlight brightness based on the proportion of the current frame's display window to the total display area, thereby increasing the brightness of local areas of the displayed image, expanding the brightness range of the display product, and improving the peak brightness of the display product, thus enhancing the image contrast. For example, before adjustment, if the brightness of the display product when displaying a completely white image is 900 nits, this embodiment can adjust the brightness of the display product when displaying a completely white image to 900–1400 nits.

[0075] In related technologies, display products with different specifications (such as different numbers of backlight zones) are not compatible with local dynamic dimming algorithms. Furthermore, when performing local dynamic dimming, the parameters used need to be looked up from a display lookup table (LUT), resulting in significant hardware space overhead. This embodiment uses a formula-based calculation method to obtain the weight coefficients, which can be calculated using only two functions, reducing computational complexity and avoiding the use of LUTs, thus reducing hardware space overhead.

[0076] In some embodiments, driving each of the backlight zones to emit light according to the backlight value includes:

[0077] The backlight zones are driven to emit light in the next frame based on the backlight value.

[0078] In this embodiment, the backlight value can be stored and output in the next frame of the display screen to drive the backlight zones to emit light. The data storage medium includes various forms of computer-readable memory, such as RAM, cache, ROM, etc. In order to balance the brightness information within the same frame, the backlight value of the same frame is multiplied by the same weighting coefficient, and the backlight value is output one frame later. That is, the backlight information calculated using the current frame is output when the screen enters the next frame. This does not affect the display effect and can save storage space for screen information, reducing hardware overhead.

[0079] Embodiments of the present invention also provide a backlight control device applied to a backlight source, the backlight source including multiple backlight zones, the multiple backlight zones being arranged in an array, such as... Figure 6 As shown, the backlight control device includes:

[0080] The first calculation module 21 is used to calculate the maximum backlight sum of all the backlight zones;

[0081] The second calculation module 22 is used to determine the ratio parameter based on the maximum backlight and the ratio of the current frame display window to the total display area;

[0082] The third calculation module 23 is used to determine the weighting coefficient based on the maximum backlight and the ratio parameter;

[0083] The processing module 24 is used to adjust the initial backlight value of each backlight zone according to the weighting coefficient to obtain the backlight value of each backlight zone, and drive each backlight zone to emit light according to the backlight value.

[0084] In this embodiment, a proportional parameter is obtained based on the maximum backlight and the proportion of the current frame display window to the total display area. A weighting coefficient is then determined based on the maximum backlight and the proportional parameter. The initial backlight value of each backlight partition is adjusted according to the weighting coefficient to obtain the backlight value of each backlight partition. This embodiment can adjust the backlight brightness according to the proportion of the current frame display window to the total display area, thereby increasing the brightness of local areas of the display screen, expanding the brightness range of the display product, increasing the peak brightness of the display product, and thus improving the screen contrast.

[0085] In some embodiments, the maximum backlight is determined by the number of backlight zones and the maximum backlight value of the backlight zones.

[0086] In some embodiments, the weighting coefficient PK_W is calculated using the following formula:

[0087] PK_W = 2 53 / (Sum Total -TH) 2

[0088] Among them, Sum Total TH represents the maximum backlight intensity, and TH represents the scaling parameter.

[0089] In some embodiments, the apparatus further includes:

[0090] The fourth calculation module is used to calculate the backlight sum of all the backlight partitions in the current frame;

[0091] The processing module 24 is specifically used to adjust the initial backlight value of each backlight zone according to the weight coefficient, the maximum backlight sum, and the backlight sum when the weight coefficient is not 0 and the backlight sum is greater than the ratio parameter.

[0092] In some embodiments, the processing module 24 is further configured to adjust the initial backlight value of the backlight zone using the following formula when the weighting coefficient is 0 or the backlight sum is less than the scaling parameter:

[0093] BL Peak (i,j)=BL in (i,j)×2 N ;

[0094] Among them, BL Peak (i,j) represents the backlight value of the backlight zone in the i-th row and j-th column, BL in (i,j) represents the initial backlight value of the backlight partition in the i-th row and j-th column, N = AB, where A is the number of bits of the driving data that drives the backlight partition to emit light, and B is the number of bits of the initial backlight value.

[0095] In some embodiments, the processing module 24 is specifically used to adjust the initial backlight value of the backlight zone using the following formula:

[0096]

[0097] Among them, BL Peak (i,j) represents the backlight value of the backlight zone in the i-th row and j-th column, BL in (i,j) represents the initial backlight value of the backlight zone in the i-th row and j-th column, Sum Total For the maximum backlight and Sum BL For the backlight and, PK W The weighting coefficient is denoted as .

[0098] In some embodiments, the processing module 24 is specifically configured to drive the backlight zone to emit light in the next frame according to the backlight value.

[0099] This invention also provides a display device, which includes the aforementioned backlight control device. The display device includes, but is not limited to, components such as: a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply. Those skilled in the art will understand that the structure of the display device described above does not constitute a limitation on the display device. The display device may include more or fewer of the aforementioned components, or a combination of certain components, or different arrangements of components. In this invention, the display device includes, but is not limited to, a monitor, a mobile phone, a tablet computer, a television set, a wearable electronic device, and a navigation display device.

[0100] The display device can be any product or component with display function, such as an LCD TV, LCD monitor, digital photo frame, mobile phone, or tablet computer. The display device also includes a flexible circuit board, a printed circuit board, and a backplate.

[0101] Embodiments of the present invention also provide a backlight control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the program, it implements the backlight control method described above. This embodiment can be implemented not only on a computer but also on a hardware processor. The processor can be a central processing unit (CPU), a field-programmable gate array (FPGA), or other processing units with data processing capabilities and / or instruction execution capabilities; it can be a general-purpose processor or a dedicated processor.

[0102] Embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the backlight control method as described above.

[0103] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage, or any other non-transferable medium that can be used to store information accessible to the computer-readable terminal device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0104] In the various method embodiments of the present invention, the sequence numbers of each step are not intended to limit the order of the steps. For those skilled in the art, any changes in the order of the steps without creative effort are also within the scope of protection of the present invention.

[0105] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, since the embodiments are basically similar to the product embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the product embodiments.

[0106] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A backlight control method, characterized in that, Applied to a backlight source, the backlight source comprising multiple backlight zones, the multiple backlight zones being arranged in an array, the backlight control method comprising: Calculate the maximum backlight sum for all said backlight zones; The proportional parameters are determined based on the maximum backlight and the proportion of the current frame display window to the total display area. The weighting coefficients are determined based on the maximum backlight and the proportional parameters. The initial backlight value of each backlight zone is adjusted according to the weighting coefficient to obtain the backlight value of each backlight zone, and each backlight zone is driven to emit light according to the backlight value. The method further includes: Calculate the backlight sum of all backlight zones in the current frame; The step of adjusting the initial backlight value of each backlight zone according to the weighting coefficient includes: When the weighting coefficient is not 0 and the backlight sum is greater than the ratio parameter, the initial backlight value of each backlight zone is adjusted according to the weighting coefficient, the maximum backlight sum, and the backlight sum.

2. The backlight control method according to claim 1, characterized in that, The maximum backlight value is determined by the number of backlight zones and the maximum backlight value of each backlight zone.

3. The backlight control method according to claim 1, characterized in that, The weighting coefficient Calculate using the following formula: in, TH represents the maximum backlight intensity, and TH represents the scaling parameter.

4. The backlight control method according to claim 1, characterized in that, The method further includes: When the weighting coefficient is 0 or the backlight sum is less than the proportional parameter, the initial backlight value of the backlight zone is adjusted using the following formula: ； in, Let i be the backlight value of the i-th row and j-th column backlight zone. Let N be the initial backlight value of the backlight partition in the i-th row and j-th column, where N = AB, A is the number of bits of the driving data that drives the backlight partition to emit light, and B is the number of bits of the initial backlight value.

5. The backlight control method according to claim 1, characterized in that, The adjustment of the initial backlight value of each backlight zone based on the weighting coefficient, the maximum backlight sum, and the backlight sum includes: The initial backlight value of the backlight zone is adjusted using the following formula: in, Let i be the backlight value of the i-th row and j-th column backlight zone. Let be the initial backlight value for the backlight zone in the i-th row and j-th column. For the maximum backlight, For the backlight and, The weighting coefficient is denoted as .

6. The backlight control method according to claim 1, characterized in that, The step of driving each of the backlight zones to emit light according to the backlight value includes: The backlight zones are driven to emit light in the next frame based on the backlight value.

7. A backlight control device, characterized in that, Applied to a backlight source, the backlight source includes multiple backlight zones, and the multiple backlight zones are arranged in an array. The backlight control device includes: The first calculation module is used to calculate the maximum backlight sum of all said backlight zones; The second calculation module is used to determine the ratio parameter based on the maximum backlight and the ratio of the current frame display window to the total display area. The third calculation module is used to determine the weighting coefficients based on the maximum backlight and the proportional parameters. The processing module is used to adjust the initial backlight value of each backlight zone according to the weighting coefficient to obtain the backlight value of each backlight zone, and drive each backlight zone to emit light according to the backlight value. The device further includes: The fourth calculation module is used to calculate the backlight sum of all the backlight partitions in the current frame; The processing module is specifically used to adjust the initial backlight value of each backlight zone according to the weight coefficient, the maximum backlight sum, and the backlight sum when the weight coefficient is not 0 and the backlight sum is greater than the ratio parameter.

8. A backlight control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that, When the processor executes the program, it implements the backlight control method as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the backlight control method as described in any one of claims 1-6.

Images