Black bar insertion method of LED backlight panel in PWM dimming mode

Abstract

The invention discloses a black frame insertion method of an LED backlight panel in a PWM dimming mode. The LED backlight panel comprises an LED light-emitting element and an LED driving unit connected with the LED light-emitting element. The LED driving unit further comprises a PWM signal generation unit, the PWM signal generation unit generates a PWM modulation signal, and the PWM modulation signal is used for controlling the brightness of the LED light-emitting element; the black frame insertion method comprises the following steps: after a field synchronization signal of each frame of display image arrives and a PWM signal generation unit passes through a preset delay time length, converting a PWM modulation signal output by the PWM signal generation unit into a fixed low-level signal to be output, and delaying the fixed low-level signal for a preset black frame insertion time length; and after the black frame insertion duration, the PWM signal generation unit recovers to output the PWM modulation signal.

Description

Technical Field

[0001] This invention relates to the field of LED backlight driving technology, and in particular to a black insertion method for an LED backlight panel in PWM dimming mode. Background Technology

[0002] With the development of display technology, Mini-LED, OLED, and Micro-LED displays have gradually become the three main directions of display technology development, building upon traditional LCD displays. However, OLED display technology is limited by material characteristics, and the pixel ablation problem remains difficult to solve. Micro-LED technology still needs to improve the efficiency of mass transfer technology to make it more cost-effective for large-size displays. Therefore, currently, LCD displays using direct-lit Mini-LED backlight panels are the best display solution. A direct-lit Mini-LED backlight panel refers to a high-density LED array composed of even finer Mini LED chips (smaller than 100 micrometers in size), and the entire backlight panel can be divided into multiple backlight zones, with the number of each zone increasing from tens to hundreds or even thousands compared to traditional LEDs.

[0003] like Figure 1 As shown, in current mini-LED applications, the PWM signal frequency controlling LED brightness is typically much higher than the brightness refresh rate. The brightness refresh rate is usually between 50Hz and 240Hz (i.e., the VSYNC frequency), while the PWM signal frequency controlling the LED switch is often between 2kHz and 32kHz to achieve better display effects. However, for LED driver chips, the PWM signal is often out of sync with the VSYNC signal. When the screen aims for better motion picture display (eliminating motion blur), it often briefly turns off the backlight when the LCD screen flips (commonly known as "black smothering"). This is done by eliminating a fixed number of PWM signals. Because VSYNC and PWM are out of sync and have no fixed phase relationship, this results in an error of 0 to 1 PWM signal at both the start and end positions of the black smothering.

[0004] Therefore, it is evident that the existing technology requires a new method for black insertion of LED backlight panels in PWM dimming mode, so that the black insertion signal can be synchronized with the PWM signal. Summary of the Invention

[0005] The technical objective of this invention is to provide an LED backlight driving method that enables the black insertion signal and the PWM signal to be synchronized.

[0006] Based on the above technical objectives, the present invention provides a black insertion method for an LED backlight panel in PWM dimming mode. The LED backlight panel includes an LED light-emitting element and an LED driving unit connected to the LED light-emitting element. The LED driving unit receives a backlight brightness signal that controls the LED light-emitting element and drives the LED light-emitting element to emit light according to the backlight brightness signal. The LED driving unit also includes a PWM signal generation unit that generates a PWM modulation signal, which is used to control the brightness of the LED light-emitting element.

[0007] The black insertion method includes:

[0008] After the field synchronization signal of each frame of the displayed image arrives, the PWM signal generation unit, after a predetermined delay, converts the output PWM modulation signal into a fixed low-level signal and delays it for a predetermined black insertion time.

[0009] After the blackout period has elapsed, the PWM signal generation unit resumes outputting the PWM modulation signal.

[0010] In one embodiment, the PWM signal generation unit is a counter unit.

[0011] In one embodiment, after a predetermined delay, the counter unit is forced to output the maximum or minimum count value.

[0012] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0014] Figure 1 This is a schematic diagram of the signal waveform for black insertion in the PWM dimming mode of an existing LED backlight panel;

[0015] Figure 2 This is a schematic diagram of the signal waveform for black insertion in the LED backlight panel of the present invention under PWM dimming mode. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0017] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this invention, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And when a second element, component, area, layer, or portion is discussed, it does not imply that the first element, component, area, layer, or portion necessarily exists in this invention.

[0018] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0020] Example 1

[0021] The LED backlight panel of this embodiment includes an LED light-emitting element and an LED driving unit connected to the LED light-emitting element. The LED driving unit receives a backlight brightness signal that controls the LED light-emitting element and drives the LED light-emitting element to emit light according to the backlight brightness signal.

[0022] The LED driving unit further includes a PWM signal generation unit, which generates a PWM modulation signal, and the PWM modulation signal is used to control the brightness of the LED light-emitting element;

[0023] In this embodiment, the PWM signal generation unit is a counter unit. The period of the PWM modulation signal is defined by the starting count value and the maximum count value of the counter unit, and the duty cycle of the PWM modulation signal is defined by the duty cycle value of the counter unit.

[0024] like Figure 2 As shown, the method for black insertion in PWM dimming mode according to the present invention includes:

[0025] After the field synchronization signal of each frame of the displayed image arrives, the PWM signal generation unit, after a predetermined delay, converts the PWM modulation signal output by the PWM signal generation unit into a fixed low-level signal output, and delays for a predetermined black insertion time.

[0026] In this embodiment, when the PWM signal generation unit is a counter unit, after a predetermined delay, the counter unit is forced to output the maximum count value (corresponding to an incrementing counter) or the minimum count value (corresponding to a decrementing counter).

[0027] After the blackout period has elapsed, the PWM signal generation unit resumes outputting the PWM modulation signal.

[0028] In this invention, black insertion of the LED backlight panel is achieved by truncating the PWM modulation signal, and the duration of black insertion can be strictly synchronized with the PWM modulation signal.

[0029] This invention can be any possible system, method, and / or computer program product at the level of integrated technical detail. The computer program product may include a computer-readable storage medium (or media) having computer-readable program instructions thereon for causing a processor to execute aspects of the invention. The computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: a portable computer floppy disk, a hard disk, random access memory (RAM), read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), a portable optical disc read-only memory (CD-ROM), a digital universal disc (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or raised structure in a groove on which instructions are recorded, and any suitable combination of the foregoing. A computer-readable storage medium, as used herein, should not be construed as a transient signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., optical pulses through fiber optic cables), or electrical signals transmitted through wires.

[0030] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a suitable computing / processing device, or via a network, such as the Internet, a local area network (LAN), a wide area network (WAN), and / or a wireless network, to an external computer or external storage device. This network may include copper transmission cables, optical fiber transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to a computer-readable storage medium within the suitable computing / processing device.

[0031] Computer-readable program instructions used to perform the operations of this invention may be assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, configuration data for integrated circuits, or source code or object code written in one or more programming languages ​​and any combination of procedural programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet through an Internet service provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs) may execute the computer-readable program instructions by utilizing state information from the computer-readable program instructions to personalize the electronic circuitry and thereby perform aspects of the invention.

[0032] This document describes aspects of the invention with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0033] These computer-readable program instructions can be provided to a computer's processor or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, create a mechanism for implementing flowcharts and / or blocks. Figure 1 Means for the functions / actions specified in one or more boxes. These computer-readable program instructions may also be stored in a computer-readable storage medium capable of guiding a computer, a programmable data processing apparatus and / or other apparatus operating in a particular manner, such that the computer-readable storage medium storing the instructions includes an article of manufacture comprising instructions for implementing aspects of the functions / actions specified in the flowchart and / or block diagram boxes.

[0034] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other apparatus to cause a series of operational steps to be performed on the computer, other programmable devices or other apparatus for producing computer-implemented processes, such that the instructions executed on the computer, other programmable devices or other apparatus perform the functions / actions specified in the flowchart and / or block diagram boxes.

[0035] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of instructions comprising one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions indicated in a block may occur outside the order indicated in the diagram. For example, two blocks shown consecutively may actually be completed as a single step, executed concurrently, substantially concurrently, in a manner that overlaps partially or entirely in time, depending on the functions involved, or sometimes these blocks may be executed in reverse order. It will also be noted that each block illustrated in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action or executes a combination of dedicated hardware and computer instructions.

[0036] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, apparatus (devices), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0037] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0038] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

Claims

1. A method for black frame insertion of an LED backlight panel in a PWM dimming mode, the method comprising: the LED backlight panel comprising LED light emitting elements and an LED driving unit connected to the LED light emitting elements, the LED driving unit receiving a backlight brightness signal for controlling the LED light emitting elements and driving the LED light emitting elements to emit light according to the backlight brightness signal, the LED driving unit further comprising a PWM signal generating unit, the PWM signal generating unit generating a PWM modulation signal for controlling the brightness of the LED light emitting elements; the method comprising: after a field synchronization signal of each frame of a display image arrives, the PWM signal generating unit changing the PWM modulation signal output by the PWM signal generating unit to a fixed low-level signal output after a predetermined delay time, and delaying for a predetermined black frame insertion time; after the black frame insertion time, the PWM signal generating unit resumes outputting the PWM modulation signal. The PWM signal generating unit is a counter unit. After the predetermined delay time, the counter unit is forced to output a maximum count value or a minimum count value. The memory is configured to store one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the steps of the method of any one of claims 1-3. The computer instructions, when executed by the processor, implement the steps of the method of any one of claims 1-3.

2. The black insertion method of claim 1, wherein, 6.A computer program product comprising computer programs / instructions, which, when executed by a processor, implement the steps of the method of any one of claims 1-3.

3. The black insertion method of claim 1, wherein, ​ 4. An electronic device comprising a memory and a processor; wherein, ​ 5. A computer readable storage medium having stored thereon computer instructions, wherein, ​ ​

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