LED backlight driving system and echo information transmission method

Abstract

The application discloses an LED backlight driving system, which comprises a backlight timing controller and at least one LED driving link; a plurality of LED driving chips are arranged in the LED driving link; the plurality of LED driving chips are connected in series and form a serial communication link with the backlight timing controller; a plurality of LED driving channel pins are arranged on each of the LED driving chips, and the LED driving channel pins are used for connecting LED light emitting elements to control the LED light emitting elements to emit light; a data frame sent by the backlight timing controller to the LED driving link comprises an echo data bit; when the LED driving chip receives the echo data bit, the LED driving chip decides whether to write echo information into the echo data bit according to a driving state of the LED driving chip.

Description

Technical Field

[0001] This invention relates to the field of image display technology, and in particular to an LED backlight driving system and a method for transmitting backlight information. Background Technology

[0002] Currently, the LED driving technology used in Mini-LED backlight panels typically employs a single LED driver chip to control and drive multiple channels of LED strings, with these multiple LED driver chips connected in a single-wire chain series connection, such as... Figure 1 As shown, this method uses only a single signal line in the communication link, minimizing communication wiring and simplifying wiring in integrated circuit design. It is used in some Mini-LED backlight modules, integrated circuits, and other systems to achieve efficient and stable communication between a master and multiple slave devices. The automatic address encoding method for slave devices can quickly and accurately encode the addresses of slave devices in a chain-like communication link; the use of specific encoding methods (Manchester encoding or pulse width encoding) ensures the anti-interference and stability of data transmission.

[0003] In existing technologies, current backlight LED driver chips typically use a dedicated pin for reporting error information, with the system monitoring the pin's status in real time. When the system receives a change in the pin's status, it can immediately take appropriate measures, such as stopping output or issuing an alarm. However, sometimes, considering cost and application scenarios, the number of chip pins is limited, leaving insufficient pins for error reporting. In such cases, the driver chip will still record the error status, waiting for the host computer to read it. The drawback of this method is that the host computer needs to read it periodically, which can affect the transmission of brightness information to some extent. Another approach is to use a communication interface, such as I2C, SPI, or UART, between the chip and the system. In this case, the chip can also send error information to the host computer via the communication interface. This method also occupies the host computer's data transmission bus, affecting the transmission of brightness information. In summary, error reporting by the driver chip is a crucial mechanism for ensuring the stable operation of the LED backlight driver system. Timely error detection and reporting allow the system to take appropriate measures to prevent device damage and ensure product safety. This is especially important in Mini-LED backlight panels, where the number of LED driver chips is large, making the pin-based reporting mechanism complex and costly.

[0004] Therefore, for the existing Mini-LED backlight driving system, a new method for reporting feedback information (error information) is needed. This method can save chip pins and reduce system wiring, and avoid occupying the bandwidth of normal backlight data transmission of the LED driving system. Summary of the Invention

[0005] The technical objective of this invention is to provide an LED backlight driving system and method. The LED backlight driving system and method based on this invention can solve the problem of transmitting feedback information in existing LED driving systems. This invention not only saves chip pins and reduces system wiring, but also avoids occupying the bandwidth required for normal backlight data transmission in the LED driving system.

[0006] Based on the above technical objectives, the present invention provides an LED backlight driving system, the LED backlight driving system comprising:

[0007] Backlight timing controller and at least one LED driver link;

[0008] The LED driving link includes multiple LED driving chips; the multiple LED driving chips are connected in series and form a serial communication link with the backlight timing controller.

[0009] Each of the LED driver chips has multiple LED driver channel pins, which are used to connect to LED light-emitting elements to control the LED light-emitting elements to emit light.

[0010] The data frames sent from the backlight timing controller to the LED driver link include echo data bits;

[0011] When the LED driver chip receives the echo data bit, the LED driver chip decides whether to write echo information to the echo data bit based on its own driving state.

[0012] In one embodiment, the echo information includes, but is not limited to, LED driving voltage undervoltage information, chip operating temperature information, or driving status error information.

[0013] In one embodiment, the LED driving voltage undervoltage information is the physical sequence position of the current LED driver chip in its LED driving link.

[0014] In one embodiment, the chip operating temperature information refers to the current LED driver chip's own chip temperature information and the physical sequence position of the current LED driver chip in its LED driving link.

[0015] In one embodiment, the drive status error information is used to describe the short-circuit status information, open-circuit status information, or over-temperature protection (OT) status information of the LED drive channel pin of the LED driver chip.

[0016] In one embodiment, each LED driver chip is provided with a first data transmission port and a second data transmission port; the serial communication link refers to the first data transmission port of each LED driver chip being connected to the second data transmission port of the LED driver chip in the preceding stage adjacent to the LED driver chip, and the second data transmission port of each LED driver chip being connected to the first data transmission port of the LED driver chip in the following stage adjacent to the LED driver chip, and the first LED driver chip in the LED driving link being connected to the transmission port of the backlight timing controller Bcon.

[0017] In one embodiment, when the serial communication link is set to unidirectional transmission, the second data transmission port of the last LED driver chip in the LED driving link is connected to the input port of the backlight timing controller.

[0018] In one embodiment, when the serial communication link is set to bidirectional transmission, the second data transmission port of the last LED driver chip in the LED driving link is left floating or multiplexed as a status output port.

[0019] In one embodiment, the data frame sent by the backlight timing controller to the LED driver link includes a frame header bit, which is used to identify the physical sequence position of the driver chip that currently receives the data frame on the serial communication link.

[0020] Compared with the prior art, one or more embodiments of the present invention may have the following advantages:

[0021] In this invention, by setting the echo data bit in the driving data frame, the echo information on the driving link can be obtained for each transmission of backlight data. Therefore, there is no need to add additional chip pins, which would increase wiring, nor does it occupy the bandwidth of backlight data transmission.

[0022] Other features and advantages of the invention will be set forth in the following description, 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 and the drawings. Attached Figure Description

[0023] 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:

[0024] Figure 1 This is a schematic diagram of a single-wire serial communication link structure for an LED driver chip, as provided in existing technology.

[0025] Figure 2This is a schematic diagram of the data frame structure of the LED backlight driving system of the present invention. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Example 1

[0031] The LED backlight driving system of this embodiment includes a backlight timing controller Bcon and at least one LED driving link.

[0032] The LED driving link includes multiple LED driver chips. Each LED driver chip is provided with a first data transmission port D1 and a second data transmission port D2. The multiple LED driver chips are serially connected and form a serial communication link with the backlight timing controller Bcon.

[0033] The serial communication link refers to the connection between the first data transmission port D1 of each LED driver chip and the second data transmission port D2 of the adjacent preceding LED driver chip, and the connection between the second data transmission port D2 of each LED driver chip and the first data transmission port D1 of the adjacent following LED driver chip. The first LED driver chip in the LED driver link is connected to the transmission port of the backlight timing controller Bcon. When the serial communication link is set to unidirectional transmission, the second data transmission port of the last LED driver chip in the LED driver link is connected to the input port of the backlight timing controller Bcon. When the serial communication link is set to bidirectional transmission, the second data transmission port of the last LED driver chip in the LED driver link is left floating or multiplexed as a status output port.

[0034] Each of the LED driver chips has multiple LED driver channel pins, which are used to connect to LED light-emitting elements to control the LED light-emitting elements to emit light.

[0035] like Figure 2 As shown, in the LED driving system of the present invention, the data frame structure sent by the backlight timing controller Bcon to the LED driving link includes:

[0036] The frame header bits (Start_Bits), control command bits (Command), backlight brightness data bits (DATA), register address bits (Reg_Addr), echo data bits (Echo), data packet length bits (Data_Len), and end bits (End).

[0037] The data frame header (Start_Bits) is used to identify the physical sequence position of the driver chip that currently receives the data frame on the serial communication link. The initial data frame header (Start_Bits) sent by the backlight timing controller Bcon has a data format of "Bit S + Bit 1". When the first LED driver chip in the LED driving link receives this data frame header, it automatically adds a data bit to the header, making the header "Bit S + Bit 0 + Bit 1". The "Bit 0" represents that the first LED driver chip is the first in the physical sequence position on the serial communication link. Correspondingly, after the first LED driver chip identifies its own sequence position through the header, it collects the corresponding brightness data packet in the subsequent backlight brightness data bits as the backlight brightness data that it needs to drive for display.

[0038] Similarly, the frame header received by the first input terminal of the second LED driver chip is "Bit S + Bit 0 + Bit 1". The second LED driver chip adds a data bit to this, changing the frame header to "Bit S + Bit 0 + Bit 0 + Bit 1". The two "Bit 0"s represent the second LED driver chip's physical position in the serial communication link as the second chip. Accordingly, after the second LED driver chip identifies its own position through the frame header, it collects the corresponding brightness data packet from the subsequent backlight brightness data bits as the backlight brightness data it needs to drive for display. This process continues until all n driver chips have obtained the corresponding brightness data packet from the backlight brightness data bits as the backlight brightness data they need to drive for display.

[0039] It is important to emphasize that this invention employs a serial communication method. Therefore, each LED driver chip does not wait for the entire data frame to be received before passing it to the next-level LED driver chip. Instead, it transmits one data bit to the next-level LED driver chip after receiving each data bit and performing a read / write operation. For example, when the first LED driver chip receives Bit S in the frame header, it immediately passes Bit S to the second LED driver chip. Similarly, the second LED driver chip also immediately passes Bit S to the next-level driver chip. Therefore, the LED driver chips on the serial communication link receive Bit S almost simultaneously.

[0040] Furthermore, when the first LED driver chip receives Bit 1 of the frame header, it determines that the frame header reception is complete. Therefore, it does not immediately forward Bit 1, but instead sends Bit 0 to the next level and sends Bit 1 in the next data transmission cycle. In this way, the first LED driver chip completes the modification of the frame header data.

[0041] The different bit signals “Bit S”, “Bit 1”, and “Bit 2” of this invention can be implemented by PWM signals with different duty cycles. For example, “Bit S” is a PWM signal with a duty cycle of 50%, “Bit 0” is a PWM signal with a duty cycle of 25%, and “Bit 1” is a PWM signal with a duty cycle of 75%.

[0042] Similarly, except for the frame header data which uses the above data transmission method, the rest, such as the control command bit (Command), backlight brightness data bit (DATA), register address bit (Reg_Addr), echo data bit (Echo), and data packet length bit (Data_Len), all use this data transmission method.

[0043] The core of this invention lies in the fact that when the LED driver chip receives the echo data bit, the LED driver chip determines whether to write echo information to the echo data bit based on its own driving state. The echo information includes, but is not limited to, LED driving voltage undervoltage information, chip operating temperature information, or driving state error information.

[0044] If the current LED driver chip experiences insufficient LED driving voltage, it writes LED driving voltage undervoltage information to the echo data bit and transmits the written information to the next-level LED driver chip. If there is no insufficient LED driving voltage, the original echo data bit is not modified, and the original LED driving voltage undervoltage information is directly transmitted to the next-level LED driver chip. Furthermore, when the subsequent driver chip writes LED driving voltage undervoltage information to the echo data bit, it overwrites the LED driving voltage undervoltage information written by the previous chip. That is, the LED driving voltage undervoltage information received by the backlight timing controller Bcon is the LED driver chip in the serial communication link closest to the backlight timing controller Bcon that exhibits an LED driving voltage undervoltage state.

[0045] The LED driving voltage undervoltage information represents the physical position of the current LED driver chip in its LED driving link. Specifically, it represents the number of "Bit 0" entries in the frame header transmitted from the current LED driver chip to the next-level LED driver chip. In other words, the information in the echo data bits of this invention expresses the location information of the driver chip experiencing an LED driving voltage undervoltage state.

[0046] Furthermore, the chip operating temperature information refers to the current LED driver chip's own chip temperature information and its physical position within the LED driving link. When the LED driver chip writes temperature information to the echo data bit, it compares it with the original chip temperature value in the echo data bit. Only if the current LED driver chip's temperature value is greater than the original chip temperature value in the echo data bit will the current LED driver chip's temperature and physical position be written to the echo data bit. Therefore, the chip operating temperature information received by the backlight timing controller Bcon is the chip temperature and physical position of the LED driver chip with the highest temperature in the serial communication link.

[0047] Furthermore, the drive status error information is used to describe the short-circuit status, open-circuit status, or over-temperature protection (OT) status information of the LED drive channel pins of the LED driver chip. The short-circuit status information refers to the number of LED drive channel pins of the LED driver chip that are short-circuited, and the open-circuit status information refers to the number of LED drive channel pins of the LED driver chip that are open-circuited. Similarly, the current LED driver chip will only write the corresponding status information to the echo data bit when a short circuit, open circuit, or OT occurs in the LED drive channel pin; otherwise, the current LED driver chip will not modify the original echo data bit information. Moreover, when the current LED driver chip writes information to the echo data bit, it will overwrite the drive status error information written by the previous stage driver chip. That is, the drive status error information received by the backlight timing controller Bcon refers to the LED driver chip in the serial communication link closest to the backlight timing controller Bcon that is in a short-circuit, open-circuit, or OT state. In this invention, the drive status error information can include not only the short-circuit, open-circuit, or OT states but also the physical sequence position of the chip.

[0048] 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.

[0049] A computer-readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. The computer-readable storage medium can 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., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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 of the functions / actions specified in one or more blocks. 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 blocks.

[0054] 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 apparatuses for producing computer-implemented processes, such that the instructions executed on the computer, other programmable devices or other apparatuses perform the functions / actions specified in the flowchart and / or block diagram boxes.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 Figure 1 The steps of the function specified in one or more boxes.

Claims

1. An LED backlight driving system, characterized by, The LED backlight driving system includes: Backlight timing controller and at least one LED driver link; The LED driving link includes multiple LED driving chips; the multiple LED driving chips are connected in series and form a serial communication link with the backlight timing controller. Each of the LED driver chips has multiple LED driver channel pins, which are used to connect to LED light-emitting elements to control the LED light-emitting elements to emit light. The data frames sent from the backlight timing controller to the LED driver link include echo data bits; The displayed information includes the physical sequence position of the LED driver chip in the LED driver chain; The data frame includes a frame header, which is used to identify the physical sequence position of the driver chip that currently receives the data frame on the serial communication link; after receiving a data bit, the LED driver chip transmits a data bit to the next level LED driver chip through a read / write operation. When the LED driver chip receives the echo data bit, the LED driver chip decides whether to write echo information to the echo data bit according to its own driving state. When the subsequent LED driver chip writes echo information to the echo data bits, it overwrites the echo information written by the previous LED driver chip to the echo data bits.

2. The LED backlight driving system of claim 1, wherein, The displayed information includes, but is not limited to, LED driver voltage undervoltage information, chip operating temperature information, or driver status error information.

3. The LED backlight driving system of claim 2, wherein, The LED driving voltage undervoltage information indicates the physical position of the current LED driver chip in its LED driving link.

4. The LED backlight driving system of claim 2, wherein, The chip operating temperature information refers to the current LED driver chip's own chip temperature information and the physical sequence position of the current LED driver chip in its LED driving link.

5. The LED backlight driving system of claim 2, wherein, The drive status error information is used to describe the short circuit status, open circuit status, or over-temperature protection status of the LED drive channel pins of the LED driver chip.

6. The LED backlight driving system of claim 1, wherein, Each LED driver chip is provided with a first data transmission port and a second data transmission port; the serial communication link refers to the first data transmission port of each LED driver chip being connected to the second data transmission port of the LED driver chip in the preceding stage adjacent to the LED driver chip, and the second data transmission port of each LED driver chip being connected to the first data transmission port of the LED driver chip in the following stage adjacent to the LED driver chip; the first LED driver chip in the LED driving link is connected to the transmission port of the backlight timing controller Bcon.

7. The LED backlight driving system of claim 1, wherein, When the serial communication link is set to unidirectional transmission, the second data transmission port of the last LED driver chip in the LED driving link is connected to the input port of the backlight timing controller.

8. The LED backlight driving system of claim 1, wherein, When the serial communication link is set to bidirectional transmission, the second data transmission port of the last LED driver chip in the LED driving link is left floating or multiplexed as a status output port.

9. An LED backlight panel comprising a plurality of LED driving units and a plurality of LED lamp groups, the LED driving units being configured with the LED backlight driving system as claimed in any one of claims 1-8.

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