Display apparatus, brightness adjustment method, and electronic device

Abstract

A display apparatus, a brightness adjustment method, and an electronic device. The display apparatus comprises: a backlight unit comprising multiple backlight partitions; a backlight driver connected to the backlight unit, and configured to control the brightness of the multiple backlight partitions on the basis of respective backlight local area control signals of the multiple backlight partitions; and a controller connected to the backlight driver, and configured to: sequentially generate multiple sets of backlight data on the basis of an image frame to be displayed, wherein the multiple sets of backlight data are different, and each group of backlight data comprises the backlight local area control signals of some of the multiple backlight partitions; and sequentially provide the multiple sets of backlight data to the backlight driver within one frame duration. The display apparatus can reduce the delay of backlight refreshing and display picture refreshing.

Description

Display device, brightness adjustment method, and electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 202311865124.1 filed on December 29, 2023, and the contents of the above-mentioned Chinese patent application disclosure are hereby incorporated by reference in their entirety as a part of this application. Technical Field

[0002] Embodiments of the present disclosure relate to a display device, a brightness adjustment method, and an electronic device. Background Art

[0003] Local dimming is a display technology. The basic principle is to adjust the brightness of a specific area on the screen by controlling the brightness of the backlight behind the LCD backlight.

[0004] Local dimming technology divides the backlight into multiple zones, each of which can independently adjust brightness, allowing for brightness control in specific areas of the screen. For example, when a display needs to display deep blacks, local dimming technology can reduce or even turn off the backlight in that area, improving black performance and contrast. Summary of the Invention

[0005] At least one embodiment of the present disclosure provides a display device, comprising: a backlight unit, comprising a plurality of groups of backlight partitions; a backlight driver, connected to the backlight unit and configured to control the brightness of the plurality of groups of backlight partitions according to respective backlight local control signals of the plurality of groups of backlight partitions; and a controller, connected to the backlight driver and configured to: generate a plurality of groups of backlight data according to a frame of image to be displayed, the plurality of groups of backlight data being different, each group of backlight data including the backlight local control signals of some groups of backlight partitions among the plurality of groups of backlight partitions; and provide the plurality of groups of backlight data to the backlight driver in sequence within one frame time.

[0006] For example, in the display device provided by some embodiments of the present disclosure, the multiple groups of backlight data are different from each other, and the multiple groups of backlight data respectively include the backlight local control signals of different backlight partition groups among the multiple groups of backlight partitions.

[0007] For example, in the display device provided by some embodiments of the present disclosure, each group of backlight data includes a data signal, the data signal includes a header and the backlight local control signal, the header is used to indicate the target backlight partition group among the multiple groups of backlight partitions to which the backlight local control signal included in the data signal belongs, and the headers of the multiple groups of backlight data are different from each other.

[0008] For example, in the display device provided by some embodiments of the present disclosure, the data signal further includes a command for indicating whether the data signal includes the local backlight control signal.

[0009] For example, in the display device provided by some embodiments of the present disclosure, the controller is connected to the backlight driver in a peripheral interface manner, and the multiple groups of backlight data are transmitted through the peripheral interface.

[0010] For example, in the display device provided by some embodiments of the present disclosure, the display device further includes a display panel, and the time length between the moment when the display data received by the display panel is switched from the first frame to the second frame and the moment when the duty ratio of the cathode or anode of the backlight unit is switched from the first frame to the second frame is less than 1.23 times the time length of one frame.

[0011] For example, in the display device provided by some embodiments of the present disclosure, the time length between the moment when the display data received by the controller is switched from the first frame to the second frame and the moment when the duty ratio of the cathode or anode of the backlight unit is switched from the first frame to the second frame is less than or equal to 0.55 times the time length of one frame.

[0012] For example, in the display device provided by some embodiments of the present disclosure, the time length between the moment when the display data received by the controller is switched from the first frame to the second frame and the moment when the duty ratio of the cathode or anode of the backlight unit is switched from the first frame to the second frame is 0.35 to 0.55 times the time length of one frame.

[0013] For example, in the display device provided by some embodiments of the present disclosure, the backlight unit includes M groups of backlight partitions, and the controller is configured to: within one frame time, sequentially provide N groups of backlight data to the backlight driver, where M is a positive integer greater than or equal to 2, and 2 ≤ N ≤ M.

[0014] For example, in the display device provided by some embodiments of the present disclosure, M is a positive integer greater than or equal to 3, N < M, the data volume of the Nth group of backlight data is greater than the data volume of each of the other groups, and the Nth group of backlight data is the last group of backlight data within one frame time.

[0015] For example, in the display device provided by some embodiments of the present disclosure, N = M - 1.

[0016] For example, in the display device provided by some embodiments of the present disclosure, N = M - P, and the data volume of the Nth group of backlight data is (P + 1) times the data volume of each of the other groups.

[0017] For example, in the display device provided in some embodiments of the present disclosure, the starting point of one frame time is the starting point when the display panel receives one frame of display data, and the end point of one frame time is the starting point when the display panel receives the next frame of display data.

[0018] For example, in the display device provided in some embodiments of the present disclosure, the backlight unit includes M groups of backlight partitions, and the controller is configured to: from the moment when the backlight data of the K+1th group of backlight partitions in the M groups of backlight partitions is generated, provide the multiple groups of backlight data to the backlight driver in sequence within one frame time, wherein M is a positive integer greater than or equal to 2, and K is a positive integer greater than 0 and less than (M-1).

[0019] For example, in the display device provided in some embodiments of the present disclosure, the backlight data from the 1st group of backlight partitions to the MKth group of backlight partitions are respectively regarded as a group of backlight data; and the backlight data from the backlight partitions of the M-K+1th group to the backlight partitions of the Mth group are respectively merged into a group of backlight data.

[0020] For example, in the display device provided in some embodiments of the present disclosure, the controller is configured to provide the backlight data of the i-th group of backlight partitions to the backlight driver while obtaining the backlight local control signal of the i+K+1-th group of backlight partitions, so that the backlight driver drives the i-th group of backlight partitions, where i is a positive integer less than M-K+1.

[0021] For example, in the display device provided in some embodiments of the present disclosure, K=2.

[0022] For example, in the display device provided by some embodiments of the present disclosure, the controller is further configured to provide a synchronization signal to the backlight driver, wherein the synchronization signal is used to instruct the controller to start transmitting the backlight data, and wherein the synchronization signal includes M valid pulse widths in each frame.

[0023] For example, in the display device provided by some embodiments of the present disclosure, the controller provides the backlight data to the backlight driver at each valid edge of the synchronization signal.

[0024] For example, in the display device provided in some embodiments of the present disclosure, the backlight driver includes: a microcontroller unit and a storage unit, the storage unit being used to store the backlight driving signals of each of the multiple backlight partitions, the microcontroller unit being configured to: receive each group of backlight data provided by the controller; determine the target backlight partition to which the backlight local control signal in each group of backlight data belongs based on the header; obtain a global backlight driving signal; determine the target backlight driving signal of the target backlight partition based on the global backlight driving signal and the backlight local control signal; and update the target backlight driving signal to the data address corresponding to the target backlight partition in the storage unit.

[0025] For example, in the display device provided in some embodiments of the present disclosure, the backlight driver also includes a backlight driver chip, the backlight unit includes M groups of backlight partitions, and the microcontroller unit is further configured to receive a synchronization signal provided by the controller and directly provide the synchronization signal to the backlight driver chip, wherein the synchronization signal includes M valid pulse widths in each frame, and the valid pulse width of the synchronization signal indicates the backlight data transmission. The microcontroller unit is also configured to update to the data address in response to the target backlight drive signal, and provide the multiple backlight drive signals stored in the storage unit to the multiple backlight driver chips on the valid edge of the synchronization signal.

[0026] For example, in the display device provided in some embodiments of the present disclosure, the microcontroller unit is further configured to: in response to the global backlight drive signal changing to an updated value, determine whether the duration of the updated value is greater than or equal to a preset threshold; and in response to the duration of the updated value being greater than or equal to the preset threshold, re-determine the target backlight drive signal based on the updated value and the backlight local control signal.

[0027] For example, in the display device provided in some embodiments of the present disclosure, the micro control unit is configured to receive each set of backlight data through direct memory access.

[0028] For example, in the display device provided in some embodiments of the present disclosure, each group of backlight data also includes: a chip select signal transmitted by a chip select signal line, the backlight data is written into a receiving register, and at the rising edge of the chip select signal, the backlight data in the receiving register is written into a storage register and the receiving register is cleared.

[0029] For example, in the display device provided by some embodiments of the present disclosure, the global backlight driving signal is used to indicate the global duty cycle of multiple groups of backlight partitions.

[0030] For example, in the display device provided in some embodiments of the present disclosure, the backlight local control signal is used to indicate the local duty cycle of some backlight partitions in the multiple groups of backlight partitions.

[0031] For example, in the display device provided in some embodiments of the present disclosure, the backlight unit includes light emitting diodes arranged in an array, and each row of light emitting diodes serves as one of the multiple groups of backlight partitions.

[0032] For example, in the display device provided in some embodiments of the present disclosure, the display panel is coupled to the backlight unit, and the backlight unit is configured to provide a planar light source for display of the display panel.

[0033] At least one embodiment of the present disclosure also provides a brightness adjustment method for a backlight unit, wherein the backlight unit includes multiple groups of backlight partitions, and the method includes: generating multiple groups of backlight data in sequence according to a frame of image to be displayed, the multiple groups of backlight data are different, and each group of backlight data includes backlight local control signals of some backlight partitions in the multiple groups of backlight partitions; and providing the multiple groups of backlight data to a backlight driver in sequence within one frame time, and the backlight driver controlling the brightness of the multiple groups of backlight partitions according to the respective backlight local control signals of the multiple groups of backlight data.

[0034] For example, in the adjustment method provided in some embodiments of the present disclosure, the multiple groups of backlight data are provided to the backlight driver in sequence within one frame time, including: starting from generating the backlight local control signal of the K+1th group of backlight partitions in the M groups of backlight partitions, and providing the multiple groups of backlight data to the backlight driver in sequence within one frame time, wherein M is a positive integer greater than or equal to 2, and K is a positive integer greater than 0 and less than (M-1).

[0035] For example, in the adjustment method provided in some embodiments of the present disclosure, starting from generating the backlight local control signal of the K+1th group of backlight partitions in the M groups of backlight partitions, the multiple groups of backlight data are provided to the backlight driver in sequence within one frame time, including: while obtaining the backlight local control signal of the i+Kth group of backlight partitions, providing the backlight data of the i-th group of backlight partitions to the backlight driver, where i is a positive integer less than M-K+1.

[0036] For example, in the adjustment method provided in some embodiments of the present disclosure, the multiple groups of backlight data respectively include the backlight local control signals of different backlight partition groups in the multiple groups of backlight partitions.

[0037] For example, in the adjustment method provided in some embodiments of the present disclosure, each group of backlight data includes a data signal, the data signal includes a header and the backlight local control signal, the header is used to indicate the target backlight partition group among the multiple groups of backlight partitions to which the backlight local control signal included in the data signal belongs, and the headers of the multiple groups of backlight data are different.

[0038] At least one embodiment of the present disclosure further provides an electronic device, including: the display device provided by any embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limiting the present disclosure.

[0040] FIG1A is a schematic diagram of a backlight unit;

[0041] FIG1B shows a schematic diagram of a display device provided by at least one embodiment of the present disclosure;

[0042] FIG1C is an exemplary system structure diagram of the display device shown in FIG1B according to at least one embodiment of the present disclosure;

[0043] FIG2 is a schematic diagram showing an SPI signal provided by a full-frame SPI according to at least one embodiment of the present disclosure;

[0044] 3A to 3G are schematic diagrams showing a plurality of data packets provided to a backlight driver according to at least one embodiment of the present disclosure;

[0045] FIG4 is a schematic diagram showing the delay time of backlight partitions provided by an embodiment of the present disclosure;

[0046] FIG5A shows a flow chart of a method for calculating brightness control signals for each backlight partition provided by at least one embodiment of the present disclosure;

[0047] FIG5B shows a flow chart of a method for updating a PWM value provided by at least one embodiment of the present disclosure;

[0048] FIG6A shows a signal timing diagram of a controller generating backlight data for all backlight partitions and then sending the backlight data;

[0049] FIG6B shows a timing diagram of signals generated and sent by a controller according to at least one embodiment of the present disclosure; and

[0050] FIG7 is a flow chart of a method for adjusting the brightness of a backlight unit provided in some embodiments of the present disclosure. DETAILED DESCRIPTION

[0051] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0052] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0053] The present disclosure is described below using several specific embodiments. To keep the following description of the embodiments of the present disclosure clear and concise, detailed descriptions of known functions and components may be omitted. When any component of an embodiment of the present disclosure appears in more than one drawing, the component is represented by the same or similar reference numeral in each drawing.

[0054] A liquid crystal panel typically includes an array substrate and an opposing substrate (e.g., a color filter substrate) disposed relative to each other to form a liquid crystal cell. A liquid crystal layer is filled between the array substrate and the opposing substrate in the liquid crystal cell. A first polarizer is disposed on the array substrate, and a second polarizer is disposed on the opposing substrate. The polarization directions of the first polarizer and the second polarizer are perpendicular to each other. A backlight unit is disposed on the non-display side of the liquid crystal panel to provide a planar light source for the display of the liquid crystal panel. Under the action of a driving electric field formed between a pixel electrode disposed on the array substrate and a common electrode disposed on the array substrate or a common electrode disposed on the opposing substrate, the liquid crystal molecules in the liquid crystal layer twist, thereby controlling the polarization direction of light passing through the liquid crystal layer. The light transmittance is controlled in conjunction with the first polarizer and the second polarizer, thereby achieving grayscale display.

[0055] The backlight unit can be a direct-lit backlight unit or an edge-lit backlight unit. A direct-lit backlight unit includes multiple point light sources (such as light-emitting diodes (LEDs)) arranged in parallel and a diffuser. The light emitted by these point light sources is uniformed by the diffuser before being incident on the liquid crystal panel for display.

[0056] For example, high-resolution LCD panels are increasingly being used in VR devices. During VR use, the human eye is closer to the display screen, making it easier to perceive the image. Consequently, the requirements for panel resolution and display quality are becoming increasingly higher.

[0057] For example, in LCD panels, local dimming (LD) technology can be used to control the direct-lit backlight unit, thereby improving the panel's display quality. This technology not only reduces panel power consumption but also enables dynamic dimming of the backlight area, significantly increasing the contrast of the displayed image and enhancing the panel's display quality.

[0058] Local dimming technology divides the entire backlight unit into multiple independently drivable backlight blocks, each containing one or more LEDs. Based on the grayscale required for different parts of the display image, the driving current of the LEDs in the corresponding backlight blocks is automatically adjusted, enabling independent brightness adjustment of each block in the backlight unit, thereby improving the contrast of the displayed image.

[0059] For example, in an exemplary direct-lit backlight unit, a schematic diagram of the LED light source's regional division within the entire backplane is shown in FIG1A . The small square in the figure represents an LED unit, and the multiple areas separated by dashed lines represent multiple backlight sub-zones. Each backlight sub-zone includes one or more LED units and can be controlled independently of other backlight sub-zones. For example, the multiple LEDs within each backlight sub-zone are interconnected, meaning that the current flowing through the multiple LEDs within the same backlight sub-zone is consistent, resulting in substantially uniform luminous brightness. Pulse Width Modulation (PWM) technology modulates the width of a series of pulses to equivalently obtain a desired waveform. PWM is a method for digitally encoding analog signal levels. By using a high-resolution counter, the duty cycle of a square wave is modulated to encode the level of a specific analog signal. For example, the brightness of an LED can be controlled by adjusting the duty cycle within a PWM cycle. By varying the proportion of high and low levels within a cycle, the brightness (intensity) of the LED can be controlled. For example, the greater the proportion of low levels within a cycle, the brighter the luminous intensity.

[0060] With the development of local dimming technology, the dimming algorithm processing time will become longer due to the increase in the number of backlight zones and the need for fine control, resulting in a longer delay between backlight refresh and display refresh, affecting the display effect and causing screen flickering and other phenomena.

[0061] At least one embodiment of the present disclosure provides a display device. The display device includes a backlight unit, a backlight driver, and a controller. The backlight unit includes multiple groups of backlight partitions. For example, the display device can be a liquid crystal display or a liquid crystal display module. For example, the basic structure of a liquid crystal display module includes four parts: a liquid crystal display screen and its driving circuit system, a backlight source (also called a "backlight unit") and its driving circuit. The display screen cut from the box process that has not yet been attached with polarizers and bound and connected with driving circuit components is called a bare liquid crystal box, and the display screen that has been attached with polarizers and bound and connected with driving circuit components is called an Open Cell (OC). The combination of OC, backlight source and its driving circuit is called a liquid crystal display module. The driving circuit of the backlight source includes, for example, the above-mentioned backlight driver and controller. Multiple groups of backlight partitions can be driven separately, and each group of backlight partitions includes one or more LEDs.

[0062] The backlight driver is connected to the backlight unit and configured to control the brightness of the multiple backlight sub-zones according to their respective local backlight control signals. The controller is connected to the backlight driver and configured to generate multiple sets of backlight data based on a frame of image to be displayed. The multiple sets of backlight data are different, and each set of backlight data includes the local backlight control signals for some of the multiple backlight sub-zones. The multiple sets of backlight data are sequentially provided to the backlight driver within a frame time.

[0063] In some embodiments of the present disclosure, for example, the backlight unit includes backlights arranged in an array (eg, 8 rows and 8 columns), and backlights in the same row are considered as a group of backlight partitions. FIG1B shows a schematic diagram of a display device provided by at least one embodiment of the present disclosure.

[0064] As shown in FIG. 1B , the display device 100 includes a backlight unit 101 , a backlight driver 102 , and a controller 103 .

[0065] The backlight unit 101 includes multiple groups of backlight partitions. The backlight driver 102 is connected to the backlight unit 101 and is configured to control the brightness of the multiple groups of backlight partitions based on the backlight local control signals of each of the multiple groups of backlight partitions. The controller 103 is connected to the backlight driver 102 and is configured to sequentially generate multiple sets of backlight data based on a frame of image to be displayed, wherein the multiple sets of backlight data are different, and each set of backlight data includes the backlight local control signals of some of the multiple groups of backlight partitions, and sequentially provide the multiple sets of backlight data to the backlight driver within a frame time. The backlight unit 101, backlight driver 102, and controller 103 are described below in conjunction with Figure 1C.

[0066] Figure 1C is an exemplary system structure diagram of the display device 100 shown in Figure 1B provided by at least one embodiment of the present disclosure. For example, the display device 100 is implemented in this example by means of a hardware circuit. As shown in Figure 1C, the system structure includes, for example, a DC power supply 10, a first control device 11, a second control device 12, and an LED driver circuit board 13 for driving the LED to emit light. The first control device 11 can be, for example, a timing controller (Timer Control Register, TCON) and / or a system on chip (System on Chip, SOC). For example, in the example of Figure 1B, a system on chip is used as the first control device 11. The second control device 12 can, for example, include at least one of a field programmable gate array (Field-Programmable Gate Array, FPGA), an SOC, and a TCON. The LED driver circuit board 13 is an example of the above-mentioned backlight driver 102.

[0067] As shown in FIG. 1C , the LED driving circuit board 13 is connected to the backlight unit, which includes LEDs for each backlight partition.

[0068] In some examples of the present disclosure, the LED driver circuit board 13 may include a micro-control unit (MCU) 131, an LED integrated circuit driver chip 132, a DC / DC circuit 133, and a current sampling circuit 134. For example, the LED driver circuit board 13 is configured to process each frame of image signals to obtain backlight brightness data after processing for each backlight partition, and generate driving currents for different backlight partitions based on the backlight brightness data, and output these driving currents to the corresponding backlight partitions to control the LEDs in these backlight partitions to emit light through the current, that is, to control the brightness of M groups of backlight partitions through the current.

[0069] In some embodiments of the present disclosure, for example, the second control device 12 in FIG. 1C serves as the controller 103 , and the controller 103 is electrically connected to the LED driver circuit board 13 .

[0070] The MCU 131 receives the backlight local control signal (Local Dimming SPI (Serial Peripheral Interface)) from the second control device 12, and performs an "AND" operation with the brightness modulation signal (PMW) from the first control device 11 (the enable signal (BL_EN) controls whether the "AND" operation is performed), to obtain the brightness control signal of each backlight partition. The MCU 131 then outputs these brightness control signals to the LED integrated circuit driver chip 132 to achieve current control of the LEDs in each backlight partition, thereby controlling the luminous brightness of each backlight partition. For example, the second control device 12 and the first control device 11 can be implemented using a TCON. For example, the backlight local control signal and the brightness modulation signal can both be implemented by the TCON, and the embodiments of the present disclosure are not limited to this.

[0071] In some embodiments of the present disclosure, the backlight driver 102 and the controller 103 may be integrated, that is, the backlight driver 102 and the controller 103 may be different modules of the same integrated circuit, and the backlight driver 102 and the controller 103 are communicatively connected.

[0072] In some embodiments of the present disclosure, the local backlight control signal is used to indicate the local duty cycle of some backlight partitions in the multiple groups of backlight partitions. The brightness modulation signal serves as a global backlight drive signal, and the global backlight drive signal is used to indicate the global duty cycle of the multiple groups of backlight partitions, such as a PWM signal provided by a system on chip (SOC).

[0073] In some embodiments of the present disclosure, for example, the backlight unit includes M groups of backlight partitions, and the controller, such as the second control device 12, is configured to sequentially generate multiple groups of backlight data based on a frame of image to be displayed, each group of backlight data including backlight local control signals for some groups of backlight partitions, and start generating backlight local control signals for the K+1th group of backlight partitions in the M groups of backlight partitions. Within one frame time, multiple groups of backlight data are sequentially provided to the backlight driver, where M is a positive integer greater than or equal to 2, and K is a positive integer greater than or equal to 0 and less than (M-1). In this embodiment, backlight data is provided to the backlight driver starting from the K+1th group, and there is no need to obtain backlight local control signals for all backlight partitions, thereby reducing the delay between backlight refresh and display screen refresh.

[0074] For example, starting from generating the backlight local control signal of the third group of backlight partitions, the controller sequentially provides multiple groups of backlight data to the LED driving circuit board 13 .

[0075] For example, first, based on the image data of the first and second groups of partitions, the backlight local control signals of the first and second groups of partitions are calculated through spatial and temporal filtering. After the calculation of the first two groups of data is completed, the first group of backlight data is sent through SPI starting from the third group. While sending the first group of backlight data, the third group of backlight data and spatial and temporal filtering are calculated. After the calculation is completed, the second group of data is sent through SPI starting from the fourth group, and so on.

[0076] It should be noted that, although in the above embodiment the controller calculates and sends from the third group, this does not limit the present disclosure. For example, the controller may also calculate and send from the second group. That is, first, based on the image data of the first group of partitions, the backlight local control signal of the first group is calculated. After the calculation of the first group of data is completed, the first group of backlight data is sent via SPI starting from the second group. While sending the first group of backlight data, the second group of backlight data and spatial-temporal filtering are calculated. After the calculation is completed, the third group starts to send the second group of data via SPI, and so on. Those skilled in the art may also set the controller to calculate and send from the fourth group. The present disclosure does not limit which group the controller starts to calculate and send.

[0077] After the controller obtains at least the backlight local control signals of the first and second groups of partitions, it sends the first group of backlight data, so that the backlight local control signals of the first and second groups of partitions can be comprehensively considered, reducing the impact of the backlight local control signals of the second group on the backlight local control signals of the first group.

[0078] For example, the local dimming driving system is powered by an external DC power supply 10, and the supply voltage Vin is generally 24 volts (V). For example, the DC / DC circuit 133 can use a voltage conversion circuit (such as a Boost circuit) to boost the supply voltage Vin to the driving voltage required to illuminate the LEDs in each backlight partition.

[0079] Because even small fluctuations in the operating voltage of an LED can cause significant changes in the current flowing through it, the LEDs in this system can be dimmed using constant current control. To achieve constant current control, the cathodes (LED-) of the multiple LEDs connected in series in the backlight subarea are connected to a current sampling circuit 134 to monitor the current stability of the driven LEDs in real time. This current sampling circuit 134 converts the current flowing through the LEDs into a voltage signal and feeds it back to the LED integrated circuit driver chip 132. This signal is then fed back to the DC / DC circuit 133. After receiving the control signal, the DC / DC circuit 133 adjusts the output voltage input to the LED anodes (LED+), achieving current stabilization for the LEDs. For example, the converted voltage signal is sampled and compared with a preset reference voltage. If the sampled voltage is higher than the reference voltage, the current sampling circuit 134 outputs a control signal, causing the DC / DC circuit 133 to reduce the output voltage, thereby reducing the current flowing through the LEDs. Conversely, the current sampling circuit 134 outputs another control signal, causing the DC / DC circuit 133 to increase the output voltage, thereby increasing the current flowing through the LEDs. That is, the current sampling circuit 134 can be used as a negative feedback circuit to implement constant current control of the LED, so that the LED can work stably.

[0080] It should be noted that in some embodiments of the present disclosure, the number of the multiple sets of backlight data and the number of the multiple sets of backlight partitions may be the same or different. For example, the backlight data of two sets of backlight partitions may be combined into one set of backlight data.

[0081] In some embodiments of the present disclosure, multiple groups of backlight data are different from each other, and the multiple groups of backlight data respectively include backlight local control signals of different backlight partition groups in the multiple groups of backlight partitions. For example, the multiple groups of backlight data correspond to the backlight local control signals of the multiple groups of backlight partitions one by one. For example, the first group of backlight data corresponds to the backlight local control signal of the first group in the multiple groups of backlight partitions, the second backlight data corresponds to the backlight local control signal of the second group in the multiple groups of backlight partitions, and so on. For another example, at least part of the backlight data in the multiple groups of backlight data includes the backlight local control signals of at least two groups of backlight partitions. For example, the first group of backlight data includes the backlight local control signal of the first group in the multiple groups of backlight partitions, and the seventh group of backlight data includes the backlight local control signals of the seventh and eighth groups of backlight partitions in the multiple groups of backlight partitions.

[0082] In some embodiments of the present disclosure, the controller is configured to provide the backlight data of the i-th row backlight partition to the backlight driver while obtaining the backlight local control signal of the i+K-th row backlight partition, so that the backlight driver drives the i-th row backlight partition, where i is a positive integer less than M-K+1.

[0083] In some embodiments of the present disclosure, the backlight unit includes a plurality of light emitting diodes (LEDs), and each row of LEDs serves as a group of a plurality of backlight zones. Hereinafter, taking each row of LEDs as a group of backlight zones as an example, the above embodiments will be described.

[0084] For example, K = 2, M = 8. For example, first, according to the image data of the first group of backlight zones (i.e., the first row of LEDs) and the second group of backlight zones (i.e., the second row of LEDs), the local backlight control signals of the first group of backlight zones and the second group of backlight zones are calculated through spatial and temporal filtering. After the data calculation of the first 2 groups of backlight zones is completed, starting from the third group of backlight zones (i.e., the third LED), the backlight data of the first group is sent through SPI. While sending the backlight data of the first group of backlight zones, the backlight data and spatial-temporal filtering of the third group of backlight zones are calculated. After the calculation is completed, while sending the backlight data of the second group of backlight zones, the backlight data and spatial-temporal filtering of the fourth group of backlight zones are calculated. After the calculation is completed, while sending the backlight data of the third group of backlight zones, the backlight data and spatial-temporal filtering of the fifth group of backlight zones are calculated. After the calculation is completed, while sending the backlight data of the fourth group of backlight zones, the backlight data and spatial-temporal filtering of the sixth group of backlight zones are calculated. After the calculation is completed, while sending the backlight data of the fifth group of backlight zones, the backlight data and spatial-temporal filtering of the seventh group of backlight zones are calculated. After the calculation is completed, while sending the backlight data of the sixth group of backlight zones, the backlight data and spatial-temporal filtering of the eighth group of backlight zones are calculated.

[0085] For example, the backlight unit includes M groups of backlight zones, and the controller is configured to: within one frame time, sequentially provide N groups of backlight data to the backlight driver, where M is a positive integer greater than or equal to 2, and 2 ≤ N ≤ M. For example, or M = 8, N = 6, etc.

[0086] In some embodiments of the present disclosure, M is a positive integer greater than or equal to 3, N < M, the data volume of the Nth group of backlight data is greater than the data volume of each of the other groups, and the Nth group of backlight data is the last group of backlight data within one frame time.

[0087] For example, for an 8-group backlight zone, the 8-group backlight zone is divided into 7 groups of backlight data, and the seventh group of backlight data is the last group of backlight data. In this example, N = M - 1. It should be noted that the embodiments of the present disclosure do not limit M = 8, N = 7, and the above example is only one implementation manner and has no limiting effect on the present disclosure.

[0088] For example, the backlight data from the first group of backlight zones to the (M - K)th group of backlight zones are respectively used as a group of backlight data; and the backlight data of each of the backlight zones from the (M - K + 1)th group of backlight zones to the Mth group of backlight zones are combined into a group of backlight data.

[0089] For example, in the above example of K=2, M=8, the backlight data from the 1st to the 6th backlight partition groups are respectively regarded as one group of backlight data, and the backlight data from the 7th and 8th backlight partition groups are combined into one group of backlight data.

[0090] For example, while sending the backlight data of the 6th group of backlight partitions, the backlight data and spatial-temporal filtering of the 8th group of backlight partitions are calculated. After the calculation is completed, the backlight data of the 7th group of backlight partitions and the 8th group of backlight partitions are packaged into a group of backlight data and provided to the LED driver circuit board 13. Packing the backlight data of the 7th group of backlight partitions and the 8th group of backlight partitions into a group of backlight data can reduce the number of transmissions.

[0091] In other embodiments of the present disclosure, the backlight data of the 7th group of backlight partitions and the backlight data of the 8th group of backlight partitions can also be sent independently, that is, the backlight data of the 7th group of backlight partitions are sent as one data packet, and the backlight data of the 8th group of backlight partitions are sent as another data packet, which can reduce the time for DMA to transmit data.

[0092] In some embodiments of the present disclosure, N=MP, and the data size of the Nth group of backlight data is (P+1) times the backlight data size of each of the other groups. For example, the backlight data of each of the first MP-1 backlight partitions is used as a group of backlight data, and the backlight data of each of the last P+1 backlight partitions is used as the last group of backlight data. The backlight data size of this last group of backlight data is P+1 times that of each of the other groups. Packing the backlight data of the last P+1 backlight partitions into one group of backlight data can reduce latency while reducing the number of times backlight data is sent.

[0093] In some embodiments of the present disclosure, the starting point of a frame time is the starting point when the display panel receives a frame of display data, and the end point of a frame time is the starting point when the display panel receives the next frame of display data.

[0094] In some embodiments of the present disclosure, the controller and the backlight driver are connected via a peripheral interface. For example, in the structure of FIG1C , the second control device 12 is connected to the MCU via a peripheral interface, such as the aforementioned SPI interface. The SPI interface includes three logic lines: a data signal line for transmitting data signals, a clock signal line for transmitting clock signals, and a chip select signal line.

[0095] For example, each backlight data set includes a data signal, a clock signal, and a chip select signal. The data signal includes a header and a backlight local control signal. The header is used to indicate the target backlight partition group among the multiple groups of backlight partitions to which the backlight local control signal included in the data signal belongs. The headers of the multiple groups of backlight data are different.

[0096] For example, the header is used to indicate which backlight partition among multiple groups of backlight partitions the backlight local control signal included in the data signal belongs to. For example, a header value of 0x0FF8 indicates the first group of partitions; a header value of 0x1FF8 indicates the second group of partitions; a header value of 0x2FF8 indicates the third group of partitions; a header value of 0x3FF8 indicates the fourth group of partitions; a header value of 0x4FF8 indicates the fifth group of partitions; a header value of 0x5FF8 indicates the sixth group of partitions; a header value of 0x6FF8 indicates the seventh group of partitions; and a header value of 0x8FF8 indicates the eighth group of partitions. The header can be used to determine which backlight partition the backlight local control signal in the backlight data belongs to.

[0097] In some embodiments of the present disclosure, the data signal includes not only the header and the backlight local control signal but also a command, where the command is used to indicate whether the data signal includes the backlight local control signal.

[0098] For example, if the value of Command is 0xFFFC, it means that the backlight data includes a backlight local control signal.

[0099] For example, some embodiments of the present disclosure provide a data signal protocol in the format of a header (Indicator) + a command (Command) + a backlight local control signal. The header determines which backlight partition the backlight local control signal in the data signal is used to control the brightness of, and the command determines whether the data signal is a correct data signal carrying the backlight local control signal. The backlight local control signal is used to indicate the local duty cycle of the backlight partition.

[0100] In some embodiments of the present disclosure, the controller is connected to the backlight driver via a peripheral interface (eg, SPI).

[0101] FIG2 is a schematic diagram showing an SPI signal provided by a full-frame SPI according to at least one embodiment of the present disclosure.

[0102] As shown in FIG2 , the SPI signal includes a data signal D, a chip select signal CS, and a clock signal CK.

[0103] The clock signal CK is used to synchronize the transmitting end (ie, the controller) and the receiving end (ie, the LED driving circuit board 13).

[0104] The controller starts sending the data signal D at the falling edge of the chip select signal CS, and provides the data signal D during the inactive level (e.g., low level) of the chip select signal CS. In some embodiments of the present disclosure, the LED driver circuit board 13 initializes the SPI signal at the rising edge of the chip select signal CS.

[0105] Data signal D includes each group's header, command, and backlight local control signal. As shown in Figure 2, if K = 2, the controller provides the first group of backlight data to the LED driver circuit board 13 after calculating the backlight data for the second row. After calculating the backlight data for one frame, it provides the last two groups of backlight data to the LED driver circuit board 13.

[0106] It should be noted that the present disclosure does not limit the specific numerical values ​​of the prefixes and commands and the meanings corresponding to the numerical values. Those skilled in the art can design the specific numerical values ​​and meanings of the prefixes and commands on their own.

[0107] 3A to 3G are schematic diagrams illustrating a plurality of data packets provided to a backlight driver according to at least one embodiment of the present disclosure.

[0108] 3A to 3G , the controller and the backlight driver communicate via SPI. As shown in FIG3A to 3G , the SPI communication includes three logic lines, namely a data signal line DT, a chip select signal line CS', and a clock signal line CLK.

[0109] In the low level phase of the chip select signal CS', the data signal line DT transmits the backlight data according to the clock signal. Each clock cycle is used to transmit one bit of the backlight data. As described above, some embodiments of the present disclosure define a data protocol including a header, a command, and a backlight local control signal. For example, if the header and the command are both 16 bits, then the transmission of the header and the command requires 16 clock cycles. In some examples of the present disclosure, for example, the backlight unit is an 8×8 LED array, and each row of LEDs serves as a group of backlight partitions, that is, each group of backlight partitions includes 8 LEDs. If the backlight local control signal of each LED is 16 bits, then the backlight local control signal of each LED requires 16 clock cycles to be transmitted.

[0110] As shown in Figure 3A, the value of the second 16 clock cycles is 0XFFFC, which means that the data packet is correct backlight data, and the value of the first 16 clock cycles in the data packet is 0X0FF8, which means that the backlight data includes the backlight local control signal of the first group of backlight partitions. The data includes 0X0001, 0X0002, 0X0003, 0X0004, 0X0005, 0X0006, 0X0007, and 0X0008, which are the backlight local control signals for each of the multiple LEDs in the first row. It should be noted that 0X0001, 0X0002, 0X0003, 0X0004, 0X0005, 0X0006, 0X0007, and 0X0008 are only examples and do not limit the present disclosure. In actual use, these backlight local signals are determined according to the brightness required for each frame. Figures 3B to 3G are similar to Figure 3A.

[0111] Similarly, the header of FIG3B is 0X1FF8 and the command is 0XFFFC, and the data packet shown in FIG3B is the backlight local control signal of the second group of backlight partitions, that is, the data signal after the command 0XFFFC is the backlight local control signal of the second group of backlight partitions.

[0112] The header of FIG3C is 0X2FF8 and the command is 0XFFFC. The data packet shown in FIG3C includes the backlight local control signal of the third group of backlight partitions. That is, the data signal after the command 0XFFFC is the backlight local control signal of the third group of backlight partitions.

[0113] The header of FIG3D is 0X3FF8 and the command is 0XFFFC. The data packet shown in FIG3D includes the backlight local control signal of the 4th group of backlight partitions, that is, the data signal after the command 0XFFFC is the backlight local control signal of the 4th group of backlight partitions.

[0114] The header of FIG3E is 0X4FF8 and the command is 0XFFFC. The data packet shown in FIG3E includes the backlight local control signal of the 5th backlight partition group, that is, the data signal after the command 0XFFFC is the backlight local control signal of the 5th backlight partition group.

[0115] The header of FIG3F is 0X5FF8 and the command is 0XFFFC. The data packet shown in FIG3F includes the backlight local control signal of the 6th backlight partition group, that is, the data signal after the command 0XFFFC is the backlight local control signal of the 6th backlight partition group.

[0116] Figure 3G is a data packet of backlight data of the 7th row backlight partition and the 8th row backlight partition. As shown in Figure 3G, the data packet includes the header 0X6FF8, indicating that the backlight local control signal after the header 0X6FF8 is the backlight data of the seventh group of backlight partitions, and the data packet includes the header 0X7FF8, indicating that the backlight local control signal after the header 0X7FF8 is the backlight local control signal of the eighth group of backlight partitions.

[0117] In some embodiments of the present disclosure, the controller is further configured to provide a synchronization signal to the backlight driver, where the synchronization signal is used to instruct the start of transmitting the backlight data.

[0118] Regarding synchronization signals, in some examples, a synchronization signal Vsync is sent once per frame (i.e., an effective pulse width of one synchronization signal per frame), and the backlight driver outputs it at an 8x frequency. Specifically, the Vsync frequency is captured once during each power-up and compared with a default frequency. If it matches the default frequency, the default frequency is directly output (e.g., 60 Hz 8x, 480 Hz). If it does not match the default frequency, a new 8x frequency is obtained through a table lookup and output. The effective pulse width is, for example, the high level period of the synchronization signal.

[0119] In some embodiments of the present disclosure, the synchronization signal includes M effective pulse widths per frame. That is, the number of effective pulse widths of the synchronization signal is the same as the number of backlight partitions. For example, the controller sends the synchronization signal Vsync 8 times, and the backlight driver can directly output the synchronization signal Vsync after receiving it to provide a synchronization signal to the backlight driver chip (for example, the LED integrated circuit driver chip 132 in Figure 1C). This can improve data synchronization accuracy and reduce the execution time of the backlight driver.

[0120] In this embodiment, the backlight data is refreshed 8 times within one frame time, and a group of the latest backlight data is added each time. The backlight response time delay can be controlled within the range of 0.35 frames to 0.55 frames. Compared with the above example of sending the synchronization signal Vsync once per frame, after the backlight driver receives a frame of data, it outputs the frame of backlight data at a speed of 8 times the frequency. Although it is also refreshed 8 times per frame, the same data is repeated 8 times, and the backlight response time delay is about 1.25 frames. Therefore, this solution effectively improves the backlight response speed.

[0121] For example, the data provided by the controller to the backlight driver is obtained by detecting the pins of the SPI interface connecting the controller and the backlight driver, and the display data received by the controller is obtained by detecting the input pins of the controller.

[0122] In some embodiments of the present disclosure, the display device further comprises a display panel. The display panel is coupled to the backlight unit, wherein the backlight unit is configured to provide a planar light source for the display of the display panel. The length of time between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the duty cycle of the cathode or anode of the backlight unit switches from the first frame to the second frame is less than 1.23 times the length of one frame time. In this example, the length of time between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the duty cycle of the cathode or anode of the backlight unit switches from the first frame to the second frame is the backlight response time delay. The moment when the duty cycle switches from the first frame to the second frame refers to the moment when the duty cycle corresponding to the first frame switches to the duty cycle corresponding to the second frame.

[0123] In some embodiments of the present disclosure, if the LEDs of the backlight unit are connected in such a manner that the LED anodes serve as a common terminal, the anode signal of the anode of the backlight unit is detected. The time length from the moment when the display data switches from the first frame to the second frame to the moment when the duty cycle of the anode signal switches from the first frame to the second frame is less than 1.23 times the length of one frame time. If the LEDs of the backlight unit are connected in such a manner that the LED cathodes serve as a common terminal, the cathode signal of the anode of the backlight unit is detected. The time length from the moment when the display data switches from the first frame to the second frame to the moment when the duty cycle of the anode signal switches from the first frame to the second frame is less than 1.23 times the length of one frame time.

[0124] For example, if the pixel value of the first frame is 0 and the pixel value of the second frame is 255, then the first frame is 100% and the second frame is 0%.

[0125] Similarly, in some embodiments of the present disclosure, the time length between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the duty cycle of the cathode or anode of the backlight unit switches from the first frame to the second frame is less than or equal to 0.55 times the length of one frame time.

[0126] In some embodiments of the present disclosure, the time length between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the duty cycle of the cathode or anode of the backlight unit switches from the first frame to the second frame is 0.35 to 0.55 times the length of one frame time.

[0127] The display data of the first frame corresponds to the duty cycle of the cathode or anode of the backlight unit in the first frame, and the display data of the second frame corresponds to the duty cycle of the cathode or anode of the backlight unit in the second frame.

[0128] The above-mentioned embodiments of the present disclosure shorten the delay problem between backlight refresh and display screen refresh.

[0129] FIG4 is a schematic diagram showing the delay time of the backlight partitions provided by an embodiment of the present disclosure.

[0130] As shown in FIG4 , if the image switches from a black screen to a white screen at time T1, a synchronization signal Vsync is sent once in each frame, and the backlight data of multiple groups of backlight partitions are obtained before being provided to the backlight driver, and the backlight driver performs an 8-fold frequency output, in this example, the signal output by the backlight partition (for example, the signal output by the anode of the LED) is curve a. In curve a, the duty cycle of the PWM signal of the backlight partition is reduced at time T2, for example, the duty cycle of the PWM signal is reduced from 100% to 0%, so the backlight response time delay is approximately 1.25 frames.

[0131] As shown in Figure 4, if the image switches from black to white at time T1, in the embodiment of the present disclosure, the signal output by the backlight partition (e.g., the signal output by the anode of the LED) is curve b. In curve b, the duty cycle of the PWM signal of the backlight partition decreases at time T3, so the backlight response time delay can be controlled within the range of 0.35 to 0.55 frames. For example, if a frame is 16.7ms, then in the embodiment of the present disclosure, the backlight response time delay can be within the range of 6ms to 8ms.

[0132] As shown in FIG1C , in some embodiments of the present disclosure, the backlight driver includes a microcontroller unit 131 and a storage unit. The storage unit is used to store backlight drive signals for each of the plurality of backlight partitions. The microcontroller unit 131 is configured to: receive each set of backlight data provided by the controller; determine the target backlight partition to which the backlight local control signal in each set of backlight data belongs based on the header; obtain a global backlight drive signal; determine a target backlight drive signal for the target backlight partition based on the global backlight drive signal and the backlight local control signal; and update the target backlight drive signal to the data address corresponding to the target backlight partition in the storage unit.

[0133] For example, the MCU 131 receives each set of backlight data provided by the second control device 12 and determines the target backlight subarea to which the local backlight control signal in each set of backlight data belongs based on the value of the prefix. For example, if the prefix value is 0x0FF8, the target backlight subarea to which the local backlight control signal in this set of backlight data belongs is the first group of subareas. The global backlight drive signal is, for example, a brightness modulation signal obtained from the TCON 11. An AND operation is performed on the brightness modulation signal and the local backlight control signal to obtain the brightness control signal for each backlight subarea.

[0134] For example, each backlight partition corresponds to a data address, and the target backlight driving signal of the target backlight partition is written into the data address location corresponding to the target backlight partition for storage.

[0135] In some embodiments of the present disclosure, the microcontroller unit is configured to receive each set of backlight data via direct memory access (DMA). DMA allows certain hardware subsystems to access memory independently of the processing unit. For example, after receiving the SPI data, the MCU's DMA can store the backlight data using a storage register.

[0136] In some embodiments of the present disclosure, after DMA completes receiving SPI data, it enters a DMA interrupt, first performs a header determination to identify which row the data belongs to, and if it is the first row, writes the data address of the first row in the corresponding array; at the same time, it captures the brightness modulation signal to perform duty cycle calculation to determine whether the duty cycle value of the brightness modulation signal has changed, and whether the duration of the duty cycle value after the change exceeds the period of two brightness modulation signals; if so, the brightness control signal of the backlight partition is output to the LED driver chip, and the LED driver chip refreshes the backlight brightness after receiving the data. The processing flow is shown in Figure 5A.

[0137] In some embodiments of the present disclosure, the microcontroller unit is further configured to: in response to the global backlight drive signal changing to an updated value, determine whether the duration of the updated value is greater than or equal to a preset threshold; and in response to the duration of the updated value being greater than or equal to the preset threshold, re-determine the target backlight drive signal based on the updated value and the backlight local control signal.

[0138] FIG5A shows a flow chart of a method for calculating brightness control signals for each backlight partition provided by at least one embodiment of the present disclosure.

[0139] As shown in FIG5A , the method includes steps S501 to S506 .

[0140] Step S501: After DMA completes receiving SPI data, it enters DMA interruption.

[0141] Step S502: character header recognition, identifying which row the backlight data belongs to.

[0142] Step S503: Write the target backlight driving signal into the corresponding data address of the backlight local control signal array Duty1. For example, if it is the first row, write the target backlight driving signal into the first row data address of the backlight local control signal array Duty1.

[0143] Step S504: Capture the brightness modulation signal and calculate the duty cycle. For example, perform an AND operation on each element in the array Duty1 of the backlight local control signal and the brightness modulation signal to obtain an array Duty2 including the brightness control signals of each backlight subarea.

[0144] Step S505: Send the array Duty2 including the brightness control signals of each backlight partition to the LED integrated circuit driver chip 132. Output the backlight Duty2 value to the LED integrated circuit driver chip 132. After receiving the data, the LED integrated circuit driver chip 132 refreshes the backlight brightness.

[0145] Step S506: Enter the next DMA cycle.

[0146] During the execution of the thread of the method in FIG5A , another thread for updating the brightness modulation signal is also executed synchronously. FIG5B shows a flow chart of a method for updating a brightness modulation signal provided by at least one embodiment of the present disclosure. For example, the thread in FIG5B is executed by the main program and enters the subroutine shown in FIG5A after a DMA interrupt occurs.

[0147] As shown in FIG5B , the method includes steps S510 to S530 .

[0148] Step S510: Capture a brightness modulation signal.

[0149] Step S520 : Determine whether the duty cycle value of the brightness modulation signal has changed, and whether the duration of the changed duty cycle value (ie, the updated value) exceeds two periods of the brightness modulation signal.

[0150] Step S530: If the duration of the duty cycle value of the brightness modulation signal after the change exceeds two periods of the brightness modulation signal, the brightness modulation signal is updated to the duty cycle value.

[0151] If the duration of the changed PWM duty cycle value does not exceed two brightness modulation signal cycles, the process returns to step S510 .

[0152] In this embodiment, after the duty cycle of the brightness modulation signal is changed, it is further determined whether the duration of the changed duty cycle value exceeds two brightness modulation signal cycles. The brightness modulation signal is updated only when it exceeds two brightness modulation signal cycles. This can solve the backlight flicker problem caused by the brightness modulation signal capture error.

[0153] In some embodiments of the present disclosure, as shown in FIG1C , the backlight driver further includes a backlight driver chip (e.g., an LED integrated circuit driver chip 132), the backlight unit includes M groups of backlight partitions, and the microcontroller unit is further configured to receive a synchronization signal provided by the controller and directly provide the synchronization signal to the backlight driver chip, wherein the synchronization signal includes M valid pulse widths per frame, and the valid pulse width of the synchronization signal indicates backlight data transmission. The microcontroller unit is further configured to update the target backlight drive signal to the data address and provide the multiple backlight drive signals stored in the storage unit to the multiple backlight driver chips on the valid edge of the synchronization signal.

[0154] In some embodiments of the present disclosure, each set of backlight data as described above also includes: a chip select signal transmitted by a chip select signal line, the backlight driver also includes a receiving register and a storage register, the backlight data is written to the receiving register, and at the rising edge of the chip select signal, the backlight data in the receiving register is written to the storage register and the receiving register is cleared.

[0155] The SPI initialization time moves from the falling edge of CS to the rising edge of CS, that is, after the TCON data is sent. In this way, the SPI data is stored in the storage register after reception, and then the receiving register is initialized to prepare for the next data reception. Even if it is interrupted by a DMA interrupt, it will not affect the current data reception and the next data reception. If the TCON data is sent incorrectly or data is missed, the DMA interrupt cannot be completed. The erroneous data will be cleared during MCU initialization to ensure correct data reception next time.

[0156] Figure 6A shows a signal timing diagram of a controller generating backlight data for all backlight partitions and then sending the backlight data; Figure 6B shows a signal timing diagram of a controller generating and sending the backlight data provided by at least one embodiment of the present disclosure. As shown in Figure 6A, at time t1, the controller TCON sends a synchronization signal Vsync, and the synchronization signal Vsync of each frame includes a rising edge. On the rising edge of the synchronization signal Vsync, the controller TCON sends an SPI signal. After receiving the SPI signal from the controller TCON, the microcontroller unit (MCU) in the backlight driver provides a brightness control signal to the LED integrated circuit driver chip in the backlight driver on the falling edge of the synchronization signal Vsync. The controller TCON provides the SPI signal on the rising edge of the synchronization signal Vsync.

[0157] If at time t1, the display signal of the display panel (i.e., OC signal) switches to the display signal of the Nth image frame (referred to as "Nth frame"), but because the controller TCON needs to parse the display signal provided by the front end, such as the SOC, calculate the initial value of the backlight of each partition, and then perform spatial and temporal filtering to obtain the backlight local control signal, when the controller TCON completes the calculation to obtain the backlight local control signal, the rising edge of the synchronization signal Vsync has passed, and it can only wait for the next rising edge of the synchronization signal Vsync. Therefore, for a period of time after time t1, the signal provided by the controller TCON to the MCU via SPI is still the SPI signal of the N-1th frame (i.e., backlight data). That is, at the rising edge of the synchronization signal Vsync at time t1, the controller TCON provides the backlight data of the N-1th frame to the MCU via SPI.

[0158] As shown in FIG6A , in this example, the MCU outputs the synchronization signal Vsync at an 8-fold frequency, and provides an SPI signal to the LED integrated circuit driver chip at the falling edge of the 8-fold frequency synchronization signal Vsync.

[0159] As shown in Figure 6A , at time t2, the second after controller TCON provides the SPI signal for the Nth frame to the MCU in the backlight driver, the duty cycle of the brightness control signal output by the LED integrated circuit driver chip in the backlight driver changes. The time between time t2 and time t1 is approximately 1.25 frames. For example, after MCU 131 in Figure 1C performs an AND operation on the backlight local control signal and the brightness modulation signal (global PMW signal) to obtain the brightness control signals for each backlight sub-zone, the brightness control signal output by LED integrated circuit driver chip 132 changes at time t2. This means that the brightness control signal has a delay of 1.25 frames.

[0160] As shown in Figure 6A, SPI signal 601 sent by the MCU is the brightness control signal for frame N. The eight SPI signals preceding SPI signal 601 are identical and are the brightness control signals required for each LED in frame N-1. SPI signal 601 and the seven SPI signals following it are the brightness control signals required for each LED in frame N.

[0161] The LED integrated circuit driver chip outputs an LED driving signal for driving the LED according to the brightness control signal. The LED integrated circuit driver chip provides the LED driving signal with a changed duty cycle to the LED at the rising edge of the MCU synchronization signal Vsync, thereby changing the brightness of the LED.

[0162] In some embodiments of the present disclosure, the controller provides backlight data to the backlight driver on the active edge of each synchronization signal. As shown in FIG6B , the active edge of the synchronization signal is, for example, the falling edge of the synchronization signal Vsync. The controller TCON provides an SPI signal to the MCU in the backlight driver on the falling edge of each synchronization signal Vsync. The MCU in the backlight driver then provides backlight data to the LED integrated circuit driver chip in the backlight driver. As shown in FIG6B , the display signal (i.e., OC signal) of the display panel switches to the display signal of the N+1th frame at time t3. At time t3, the controller TCON issues the synchronization signal Vsync. Each frame of the synchronization signal Vsync issued by the controller TCON includes M rising edges. If the display device has eight backlight partitions, M is equal to 8. On the rising edge of the synchronization signal Vsync issued by the controller TCON, the controller TCON issues an SPI signal. The MCU in the backlight driver directly outputs the synchronization signal Vsync without the need for octave multiplication. After receiving the SPI signal from the controller TCON, the MCU in the backlight driver provides a brightness control signal to the backlight driver LED integrated circuit driver chip 132 on the falling edge of the synchronization signal Vsync.

[0163] If the image changes at time t3, the brightness control signal for the first set of backlight sub-zones output by the LED integrated circuit driver chip 132 in the backlight driver at time t4 changes. Subsequently, the brightness control signal for the second set of backlight sub-zones also changes accordingly. In other words, the delay of the brightness control signal can be controlled within the range of 0.35 to 0.55 frames.

[0164] The SPI signal 602 provided by the MCU in the backlight driver to the LED integrated circuit driver chip is the first SPI signal of the Nth frame. The SPI signal includes the brightness control signal of the first group of backlight partitions after being updated by the MCU according to the global backlight drive signal and the backlight local control signal (that is, the brightness control signal of the first group of backlight partitions is the N+1th frame image) and the brightness control signal of the second group of backlight partitions to the brightness control signal of the eighth group of backlight partitions. The brightness control signal of the second group of backlight partitions to the brightness control signal of the eighth group of backlight partitions are still the Nth frame image.

[0165] After the MCU in the backlight driver provides the SPI signal 602 to the LED integrated circuit driver chip in the backlight driver, at the rising edge of the synchronization signal Vsync provided by the MCU in the next backlight driver, the duty cycle of the LED drive signal output by the LED integrated circuit driver chip in the backlight driver has changed according to the updated brightness control signal of the first group of backlight partitions.

[0166] The SPI signal 603 provided by the MCU in the backlight driver to the LED integrated circuit driver chip is the second SPI signal of the N+1th frame. The SPI signal includes the brightness control signal of the first group of backlight partitions of the N+1th frame, the brightness control signal of the second group of backlight partitions of the N+1th frame, and the brightness control signals of the third group of backlight partitions to the eighth group of backlight partitions. The brightness control signals of the third group of backlight partitions to the eighth group of backlight partitions are still the brightness control signals of the Nth frame image.

[0167] After the MCU in the backlight driver provides the SPI signal 603 to the LED integrated circuit driver chip, at the next rising edge of the synchronization signal Vsync provided by the MCU in the backlight driver, the duty cycle of the LED drive signal output by the LED integrated circuit driver chip in the backlight driver has changed based on the updated brightness control signal of the second group of backlight sub-zones. The other groups of backlight sub-zones are similar to the first and second groups of backlight sub-zones described above and are not further described.

[0168] The LED drive signal refers to the duty cycle signal of the LED cathode / anode. When the LED drive signal of the first backlight sub-zone changes, the LED drive signal of the second backlight sub-zone has not yet been updated, so there will be a difference (for example, when the screen switches from black to white, the duty cycle of the first sub-zone increases to display the white screen, while the duty cycle of the second sub-zone has not changed at this moment and still maintains the duty cycle corresponding to the black screen).

[0169] It should be noted that the square wave signal of the LED driving signal is only a schematic representation, and in actual application, the frequency of the square wave signal may be greater than the frequency shown in FIG6B .

[0170] In some embodiments of the present disclosure, the display device further includes a display panel coupled to a backlight unit, the backlight unit being configured to provide a planar light source for displaying the display panel. For example, as described above, the display panel may be a liquid crystal display panel, and the backlight unit is disposed on a non-display side of the liquid crystal panel to provide a planar light source for displaying the liquid crystal panel.

[0171] Another aspect of the present disclosure provides a brightness adjustment method for a backlight unit, where the backlight unit includes a plurality of backlight partitions.

[0172] FIG7 shows a brightness adjustment method provided by at least one embodiment of the present disclosure. The brightness adjustment method can be applied to the display device provided by any embodiment of the present disclosure.

[0173] As shown in FIG. 7 , the brightness adjustment method includes steps S701 and S702 .

[0174] Step S701: generating multiple sets of backlight data in sequence according to a frame of image to be displayed. The multiple sets of backlight data are different, and each set of backlight data includes backlight local control signals of some backlight partitions among the multiple sets of backlight partitions.

[0175] Step S702: providing a plurality of sets of backlight data to the backlight driver in sequence within one frame time, and the backlight driver controls the brightness of the plurality of backlight subareas according to the respective backlight local control signals of the plurality of sets of backlight data.

[0176] This brightness adjustment method can reduce the delay between backlight refresh and display screen refresh.

[0177] For step S701, the multiple sets of backlight data and the backlight local control signal can be referred to the above description. Step S701 can be executed by the controller described above. For step S702, please refer to the above description. The controller can be executed by the controller.

[0178] In some embodiments of the present disclosure, multiple sets of backlight data are sequentially provided to the backlight driver within one frame time, including: starting from generating a backlight local control signal for the K+1th group of backlight partitions among M groups of backlight partitions, and sequentially providing multiple sets of backlight data to the backlight driver within one frame time, where M is a positive integer greater than or equal to 2, and K is a positive integer greater than or equal to 0 and less than (M-1).

[0179] In some embodiments of the present disclosure, starting from generating a backlight local control signal for the K+1th group of backlight partitions among the M groups of backlight partitions, multiple groups of backlight data are sequentially provided to the backlight driver within one frame time, including: while obtaining the backlight local control signal for the i+Kth group of backlight partitions, providing the backlight data of the i-th group of backlight partitions to the backlight driver, where i is a positive integer less than M-K+1.

[0180] In some embodiments of the present disclosure, the plurality of groups of backlight data respectively include backlight local control signals of different backlight zone groups among the plurality of groups of backlight zones.

[0181] In some embodiments of the present disclosure, each group of backlight data includes a data signal, the data signal includes a header and a backlight local control signal, the header is used to indicate the target backlight partition group among the multiple groups of backlight partitions to which the backlight local control signal included in the data signal belongs, and the headers of the multiple groups of backlight data are different.

[0182] In some embodiments of the present disclosure, the data signal further includes a command, and the command is used to indicate whether the data signal includes the backlight local control signal.

[0183] In some embodiments of the present disclosure, the time length between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the data transmitted by the peripheral interface switches from the first frame to the second frame is less than 1.23 times the length of one frame time; or the time length between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the duty cycle of the cathode or anode of the backlight unit switches from the first frame to the second frame is less than 1.23 times the length of one frame time.

[0184] In some embodiments of the present disclosure, the time length between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the data transmitted by the peripheral interface switches from the first frame to the second frame is 0.35 to 0.55 times the length of one frame time; or the time length between the moment when the display data received by the display panel switches from the first frame to the second frame and the moment when the duty cycle of the cathode or anode of the backlight unit switches from the first frame to the second frame is 0.35 to 0.55 times the length of one frame time.

[0185] In some embodiments of the present disclosure, a backlight driver includes a microcontroller unit that performs the following operations: receiving each set of backlight data provided by the controller; determining, based on the header, a target backlight partition to which a backlight local control signal in each set of backlight data belongs; obtaining global backlight driving parameters; determining target backlight driving parameters for the target backlight partition based on the global backlight driving parameters and the backlight local control signal; and writing the target backlight driving parameters for the target backlight partition into a data address corresponding to the target backlight partition in the backlight driver.

[0186] In some embodiments of the present disclosure, the backlight driver also includes a backlight driver chip, the backlight unit includes M groups of backlight partitions, and the microcontroller unit is further configured to receive a synchronization signal provided by the controller and directly provide the synchronization signal to the backlight driver chip, the synchronization signal includes M valid pulse widths in each frame, and the valid pulse width of the synchronization signal indicates the start of transmitting the backlight data.

[0187] In some embodiments of the present disclosure, the microcontroller unit further performs: in response to the global backlight driving parameter changing to an updated value, determining whether the duration of the updated value is greater than or equal to a preset threshold; and in response to the duration of the updated value being greater than or equal to the preset threshold, redetermining the target backlight driving parameter based on the updated value and the backlight local control signal.

[0188] In some embodiments of the present disclosure, the micro control unit is configured to receive each set of backlight data via direct memory access.

[0189] In some embodiments of the present disclosure, each set of backlight data also includes: a chip select signal transmitted by a chip select signal line, the backlight data is written into a receiving register, and at the rising edge of the chip select signal, the backlight data in the receiving register is written into a storage register and the receiving register is cleared.

[0190] It should be noted that in the embodiments of the present disclosure, the various units or components of the display device described above correspond to the various steps of the brightness adjustment method. For the description of the brightness adjustment method, reference can be made to the description of the display device, and no further details will be given here. The components and structures of the display device described above are merely exemplary and non-limiting. The display device described above may further include other components and structures as needed.

[0191] The technical effects of the storage medium provided by the embodiments of the present disclosure can be referred to the corresponding description of the image display processing method in the above embodiments, which will not be repeated here.

[0192] There are a few points to note:

[0193] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure. Other structures may refer to conventional designs.

[0194] (2) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to form new embodiments.

[0195] The foregoing description is merely an exemplary embodiment of the present disclosure and is not intended to limit the scope of protection of the present disclosure. The scope of protection of the present disclosure is determined by the appended claims.

Claims

1. A display device, comprising: A backlight unit, including multiple groups of backlight partitions; A backlight driver, connected to the backlight unit and configured to control the brightness of the multiple groups of backlight partitions according to the local backlight control signals of the respective multiple groups of backlight partitions; And A controller, connected to the backlight driver and configured to: Generate multiple groups of backlight data according to a frame of image to be displayed, at least one group of the multiple groups of backlight data being different from other groups of backlight data, and each group of backlight data including the local backlight control signals of some groups of backlight partitions among the multiple groups of backlight partitions; And Within a frame time, sequentially provide the multiple groups of backlight data to the backlight driver.

2. The display device according to claim 1, wherein, The multiple groups of backlight data are different from each other; The multiple groups of backlight data respectively include the local backlight control signals of different groups of backlight partitions among the multiple groups of backlight partitions.

3. The display device according to claim 2, wherein, Each group of backlight data includes a data signal, the data signal including a header and the local backlight control signal, the header being used to indicate the target group of backlight partitions among the multiple groups of backlight partitions to which the local backlight control signal included in the data signal belongs, and the headers of the multiple groups of backlight data being different from each other.

4. The display device according to claim 3, wherein, The data signal further includes a command, the command being used to indicate whether the data signal includes the local backlight control signal.

5. The display device according to any one of claims 1 to 4, wherein, The controller is connected to the backlight driver in a peripheral interface manner, and transmits the multiple groups of backlight data through the peripheral interface.

6. The display device according to any one of claims 1 to 5, wherein, The display device further includes a display panel, and the time length between the moment when the display data received by the display panel is switched from the first frame to the second frame and the moment when the duty ratio of the cathode or anode of the backlight unit is switched from the first frame to the second frame is less than 1.23 times the frame time length.

7. The display device according to claim 6, wherein, The time length between the moment when the display data received by the display panel is switched from the first frame to the second frame and the moment when the duty ratio of the cathode or anode of the backlight unit is switched from the first frame to the second frame is less than or equal to 0.55 times the frame time length.

8. The display device according to claim 7, wherein, The time length between the moment when the display data received by the display panel is switched from the first frame to the second frame and the moment when the duty ratio of the cathode or anode of the backlight unit is switched from the first frame to the second frame is 0.35 to 0.55 times the frame time length.

9. The display device according to any one of claims 1 to 8, wherein, The backlight unit includes M groups of backlight partitions, and the controller is configured to: Within a frame time, sequentially provide N groups of backlight data to the backlight driver, where M is a positive integer greater than or equal to 2, and 2 ≤ N ≤ M.

10. The display device according to claim 9, wherein, M is a positive integer greater than or equal to 3, N < M, The data amount of the Nth group of backlight data is greater than the data amount of each of the other groups of backlight data, and the Nth group of backlight data is the last group of backlight data within the frame time.

11. The display device according to claim 10, wherein, N = M - 1.

12. The display device according to claim 10, wherein, N = M - P, and the data amount of the Nth group of backlight data is (P + 1) times the data amount of each of the other groups of backlight data.

13. The display device according to any one of claims 9 to 12, wherein, The starting point of the frame time is the starting point when the display panel receives a frame of display data, and the ending point of the frame time is the starting point when the display panel receives the next frame of display data.

14. The display device according to any one of claims 9 to 13, wherein, The backlight unit includes M groups of backlight partitions, and the controller is configured to: Starting from the moment when the backlight data of the (K + 1)-th group of backlight partitions in the M groups of backlight partitions is generated, within one frame time, sequentially provide the multiple groups of backlight data to the backlight driver. Where M is a positive integer greater than or equal to 2, and K is a positive integer greater than 0 and less than (M - 1).

15. The display device according to any one of claims 7 to 14, wherein The backlight data from the first group of backlight partitions to the (M - K)-th group of backlight partitions are respectively used as one group of backlight data; And The backlight data of each of the backlight partitions from the (M - K + 1)-th group of backlight partitions to the M-th group of backlight partitions are merged into one group of backlight data.

16. The display device according to claim 14 or 15, wherein, The controller is configured to, when generating the local backlight control signal of the (i + K + 1)-th group of backlight partitions, provide the backlight data of the i-th group of backlight partitions to the backlight driver, so that the backlight driver drives the i-th group of backlight partitions, where i is a positive integer less than M - K + 1.

17. The display device according to any one of claims 14-16, wherein, K＝2。 18. The display device according to any one of claims 9-16, wherein, The controller is further configured to provide a synchronization signal to the backlight driver, wherein the synchronization signal is used to indicate that the controller starts to transmit the backlight data, and the synchronization signal includes M effective pulse widths in each frame.

19. The display device according to claim 18, wherein, The controller provides the backlight data to the backlight driver at the effective edge of each synchronization signal.

20. The display device according to any one of claims 3 to 19, wherein, The backlight driver includes: a micro control unit and a storage unit, and the storage unit is used to store the backlight driving signals of the multiple backlight partitions respectively. Wherein, the micro control unit is configured to: Receive each group of backlight data provided by the controller; Judge the target backlight partition to which the local backlight control signal in each group of backlight data belongs according to the header; Obtain the global backlight driving signal; Based on the global backlight driving signal and the local backlight control signal, determine the target backlight driving signal of the target backlight partition; and Update the target backlight driving signal to the data address corresponding to the target backlight partition in the storage unit.

21. The display device according to claim 20, wherein, The backlight driver further includes a backlight driving chip, the backlight unit includes M groups of backlight partitions. The micro control unit is further configured to receive the synchronization signal provided by the controller and directly provide the synchronization signal to the backlight driving chip, wherein the synchronization signal includes M effective pulse widths in each frame, and the effective pulse width of the synchronization signal indicates the transmission of the backlight data. The micro control unit is further configured to, in response to the update of the target backlight driving signal to the data address, provide the multiple backlight driving signals stored in the storage unit to the multiple backlight driving chips at the effective edge of the synchronization signal.

22. The display device according to claim 20 or 21, wherein, The micro control unit is further configured to: In response to the global backlight driving signal changing to an updated value, judge whether the duration of the updated value is greater than or equal to a preset threshold; and In response to the duration of the updated value being greater than or equal to the preset threshold, re-determine the target backlight driving signal based on the updated value and the local backlight control signal.

23. The display device according to claim 22, wherein, The micro control unit is configured to: receive each group of backlight data by means of direct memory access.

24. The display device according to claim 23, wherein, Each set of backlight data further includes: a chip select signal transmitted by a chip select signal line, and the backlight driver further includes a receiving register and a storage register. Wherein, the backlight data is written into the receiving register, and at the rising edge of the chip select signal, the backlight data in the receiving register is written into the storage register and the receiving register is cleared.

25. The display device according to any one of claims 22 to 24, wherein, The global backlight driving signal is used to indicate the global duty ratio of multiple groups of backlight partitions.

26. The display device according to any one of claims 1 to 25, wherein, The backlight local control signal is used to indicate the local duty ratio of some of the multiple groups of backlight partitions.

27. The display device according to any one of claims 1 to 26, wherein, The backlight unit includes light-emitting diodes arranged in an array, and one or more rows of light-emitting diodes form one group of the multiple groups of backlight partitions.

28. The display device according to claim 6, wherein, The display panel is coupled to the backlight unit, wherein the backlight unit is configured to provide a planar light source for the display of the display panel.

29. A method for adjusting the brightness of a backlight unit, wherein, The backlight unit includes multiple groups of backlight partitions, and the method includes: Generating multiple sets of backlight data in sequence according to a frame of image to be displayed, the multiple sets of backlight data are different, and each set of backlight data includes a backlight local control signal of some of the multiple groups of backlight partitions; and During a frame time, sequentially providing the multiple sets of backlight data to the backlight driver, and the backlight driver controls the brightness of the multiple groups of backlight partitions according to the backlight local control signals of the multiple sets of backlight data respectively.

30. The adjustment method according to claim 29, wherein, During a frame time, sequentially providing the multiple sets of backlight data to the backlight driver includes: Starting from generating the backlight local control signal of the (K + 1)-th group of backlight partitions among the M groups of backlight partitions, during a frame time, sequentially providing the multiple sets of backlight data to the backlight driver. Wherein, M is a positive integer greater than or equal to 2, and K is a positive integer greater than 0 and less than (M - 1).

31. The adjustment method according to claim 30, wherein, Starting from generating the backlight local control signal of the (K + 1)-th group of backlight partitions among the M groups of backlight partitions, during a frame time, sequentially providing the multiple sets of backlight data to the backlight driver includes: While obtaining the backlight local control signal of the (i + K)-th group of backlight partitions, providing the backlight data of the i-th group of backlight partitions to the backlight driver, where i is a positive integer less than M - K + 1.

32. The adjustment method according to claim 31, wherein, The multiple sets of backlight data respectively include the backlight local control signals of different groups of backlight partitions among the multiple groups of backlight partitions.

33. The adjustment method according to claim 32, wherein, Each set of backlight data includes a data signal, the data signal includes a header and the backlight local control signal, the header is used to indicate the target group of backlight partitions among the multiple groups of backlight partitions to which the backlight local control signal included in the data signal belongs, and the headers of the multiple sets of backlight data are different from each other.

34. An electronic device, comprising: The display device according to any one of claims 1 to 28.

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