LED backlight driving system and echo information transmission method

Abstract

The invention discloses an LED backlight driving system. The LED backlight driving system comprises a backlight time sequence controller and at least one LED driving link, the LED driving link comprises a plurality of LED driving chips; the plurality of LED driving chips are connected in series and form a serial communication link with the backlight time schedule controller; each LED driving chip is provided with a plurality of LED driving channel pins, and the LED driving channel pins are used for being connected with LED light-emitting elements so as to control the LED light-emitting elements to emit light; the data frame sent by the backlight time schedule controller to the LED driving link comprises echo data bits; and when the LED driving chip receives the echoing data bit, the LED driving chip determines whether to write echoing information into the echoing data bit or not according to the driving state of the LED driving chip.

Description

Technical Field

[0001] The present invention relates to the field of image display technology, and in particular to an LED backlight driving system and an echo information transmission method. Background Art

[0002] At present, the LED driving technology used in Mini-LED backlight panels generally uses one LED driver chip to control and drive multiple channels of LED light strings, and multiple LED driver chips are connected in series using a single-line chain, such as Figure 1 As shown. Only a single signal line is used in the communication link, which minimizes the communication wiring and facilitates simplified 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 the host and multiple slaves. The automatic address encoding method for the slave can quickly and accurately encode the address of the slave in the chain communication link; the use of a specific encoding method (Manchester encoding or pulse width encoding) ensures the anti-interference and stability of data transmission.

[0003] In the prior art, the existing backlight LED driver chip is generally used to report the echo information (error information) by setting a special pin, and the system detects the status of this pin in real time. When the system receives a change in the pin status, it can immediately take corresponding measures, such as stopping output, issuing an alarm, etc. However, sometimes considering the cost and application scenarios, the number of chip pins is small, and there are no extra pins for error reporting. The driver chip will also record the error status and wait for the host computer to read. However, the disadvantage of this method is that the host computer needs to read it regularly, which will affect the transmission of brightness information to a certain extent. There is another way. If the chip and the system are connected through a communication interface, such as I2C, SPI, UART, etc., the chip can also send error information to the host computer through the communication interface. This method will also occupy the bus for the host computer to send data, affecting the transmission of brightness information. In short, the error reporting of the driver chip is an important mechanism to ensure the stable operation of the LED backlight drive system. With timely error detection and reporting, the system can take corresponding measures to prevent device damage and ensure the safety of the product. Especially in Mini-LED backlight panels, the number of LED driver chips is large, the pin reporting mechanism is complex, and the cost is higher.

[0004] It can be seen that for the Mini-LED backlight driving system in the prior art, it is necessary to provide a new echo information (error information) reporting method, which can not only save chip pins and thus reduce system wiring, but also avoid occupying the bandwidth of the normal backlight data transmission of the LED driving system. Summary of the invention

[0005] The technical purpose to be achieved by the present invention is to provide an LED backlight driving system and driving method. The LED backlight driving system and driving method based on the present invention can solve the transmission problem of echo information in the LED driving system in the prior art. The LED backlight driving system and driving method of the present invention can not only save chip pins and thus reduce system wiring, but also avoid occupying the bandwidth of the normal backlight data transmission of 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] A backlight timing controller and at least one LED driver link;

[0008] The LED driving link includes a plurality of LED driving chips; the plurality of 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 a plurality of LED driver channel pins, and the LED driver channel pins are used to connect LED light-emitting elements to control the LED light-emitting elements to emit light;

[0010] The data frame sent by the backlight timing controller to the LED driver link includes an echo data bit;

[0011] When the LED driver chip receives the echo data bit, the LED driver chip determines whether to write the echo information into the echo data bit according to its own driving state.

[0012] In one embodiment, the echoed 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 driving chip on the 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 on the LED driver link.

[0015] In one embodiment, the driving state error information is used to express short circuit state information, open circuit state information or over-temperature protection (OT) state information of an LED driving channel pin of an LED driving chip.

[0016] In one embodiment, each of the LED driver chips is provided with a first data transmission port and a second data transmission port; the serial communication link means that the first data transmission port of each LED driver chip is connected to the second data transmission port of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port of each LED driver chip is connected to the first data transmission port of the LED driver chip of the next level adjacent to the LED driver chip, and the first LED driver chip in the LED driver link is 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 driver 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 driver 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 driving link includes a frame header bit, and the frame header bit is used to identify the physical sequence position of the driving 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 the present invention, by setting the echo data bit in the driving data frame, each transmission of backlight data can obtain the echo information on the driving link, so there is no need to increase chip pins to increase wiring, and the bandwidth of backlight data transmission is not occupied.

[0022] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a schematic diagram of the single-line serial communication link structure of the LED driver chip given in the prior art;

[0025] Figure 2It is a schematic diagram of the data frame structure of the LED backlight driving system of the present invention. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is 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 can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present invention necessarily has the first element, component, region, layer or part.

[0028] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an 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, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0029] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant 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 a plurality of LED driving chips. Each of the LED driving chips is provided with a first data transmission port D1 and a second data transmission port D2. The plurality of LED driving chips are connected in series and form a serial communication link with the backlight timing controller Bcon.

[0033] The serial communication link means that the first data transmission port D1 of each LED driver chip is connected to the second data transmission port D2 of the LED driver chip of the previous level adjacent to the LED driver chip, the second data transmission port D2 of each LED driver chip is connected to the first data transmission port D1 of the LED driver chip of the next level adjacent to the LED driver chip, and the first LED driver chip in the LED driver link is connected to the transmission port of the backlight timing controller Bcon. And 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 driving chips has a plurality of LED driving channel pins, and the LED driving channel pins are used to connect 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] Frame header bit (Start_Bits), control command bit (Command), backlight brightness data bit (DATA), register address bit (Reg_Addr), echo data bit (Echo), data packet length bit (Data_Len) and end bit (End).

[0037] The data frame header bit (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 data format of the initial data frame header bit (Start_Bits) sent by the backlight timing controller Bcon is in the form of "Bit S+Bit 1". When the first LED driver chip in the LED driver link receives the data frame header bit, it will automatically add a data bit to the header bit, and the header bit will become "Bit S+Bit 0+Bit 1". The "Bit 0" represents that the physical sequence position of the first LED driver chip on the serial communication link is the first. Correspondingly, when the first LED driver chip recognizes its own sequence position through the header bit, it collects the brightness data packet of the corresponding position in the subsequent backlight brightness data bit as the backlight brightness data that needs to be driven and displayed by itself.

[0038] Similarly, the frame header bit received by the first input end of the second LED driver chip is "Bit S+Bit 0+Bit1", and the second LED driver chip adds a data bit to it, changing the frame header bit to "Bit S+Bit 0+Bit 0+Bit1". The two "Bit 0"s represent that the second LED driver chip is the second in the physical sequence position on the serial communication link. Correspondingly, when the second LED driver chip identifies its own sequence position through the frame header bit, it collects the corresponding brightness data packet in the subsequent backlight brightness data bit as the backlight brightness data that it needs to drive and display. And so on until all n driver chips correspondingly obtain the brightness data packet in the backlight brightness data bit as the backlight brightness data that it needs to drive and display.

[0039] It should be emphasized here that the present invention adopts a serial communication method, so each LED driver chip does not wait for the data frame to be completely received before passing the complete data frame to the next-level LED driver chip, but transmits a data bit to the next-level LED driver chip after each data bit is received through a read and write operation. For example, when the first LED driver chip receives Bit S of the frame header, it will immediately pass Bit S to the second LED driver chip. Similarly, the second LED driver chip will also immediately pass Bit S to the next-level driver chip. Therefore, the LED driver chips on the serial communication link receive Bit S at almost the same time.

[0040] Furthermore, when the first LED driver chip receives Bit 1 of the frame header, it determines that the frame header has been received, so it does not forward Bit 1 immediately, but sends Bit 0 to the next level, and sends Bit 1 in the next data transmission cycle. Thus, the first LED driver chip completes the modification of the frame header data.

[0041] The different bit signals "Bit S", "Bit 1", and "Bit 1" of the present 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 bit data which adopts 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 adopt this data transmission method.

[0043] The core of the present invention is that when the LED driver chip receives the echo data bit, the LED driver chip decides whether to write the echo information to the echo data bit according to 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 has insufficient LED driving voltage, the LED driving voltage undervoltage information is written to the echo data bit, and the written LED driving voltage undervoltage information is transmitted to the next-level LED driver chip; if the LED driving voltage is not insufficient, the data of the original echo data bit is not modified, and the LED driving voltage undervoltage information of the original echo data bit is directly transmitted to the next-level LED driver chip. And when the subsequent driver chip writes the LED driving voltage undervoltage information to the echo data bit, the LED driving voltage undervoltage information written by the previous chip is overwritten, 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 that is closest to the backlight timing controller Bcon and has an LED driving voltage undervoltage state.

[0045] The LED driving voltage undervoltage information is the physical sequence position of the current LED driving chip in the LED driving link. That is, the number of "Bit0" in the frame header transmitted by the current LED driving chip to the next level LED driving chip. In other words, the information in the echo data bit of the present invention expresses the position information of the driving chip where the LED driving voltage undervoltage state occurs.

[0046] Furthermore, 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 on the LED driver link. When the LED driver chip writes temperature information to the echo data bit, it will be compared with the original chip temperature value in the echo data bit. Only when the temperature value of the current LED driver chip is greater than the chip temperature value in the original echo data bit, the temperature and physical sequence position of the current LED driver chip will be written into the echo data bit. Therefore, the chip operating temperature information received by the backlight timing controller Bcon is the chip temperature and physical sequence position of the LED driver chip with the highest temperature in the serial communication link.

[0047] Further, the driving state error information is used to express the short circuit state information, open circuit state information or over-temperature protection (OT) state information of the LED driving channel pin of the LED driver chip. The short circuit state information refers to the number of LED driving channel pins in which the LED driver chip is short-circuited, and the open circuit state information refers to the number of LED driving channel pins in which the LED driver chip is open-circuited. Similarly, only when the LED driving channel pin of the current LED driver chip is short-circuited, open-circuited or OT, the current LED driver chip will write the corresponding state information to the echo data bit, otherwise the current LED driver chip will not modify the original echo data bit information. And when the current LED driver chip writes information to the echo data bit, it will overwrite the driving state error information written by the previous driver chip. That is, the driving state error information received by the backlight timing controller Bcon is the LED driver chip in the serial communication link that is closest to the backlight timing controller Bcon and is in the short circuit, open circuit or OT state. In the present invention, the driving state error information includes the short circuit, open circuit or OT state, and the physical sequence position of the chip can also be written into the driving state error information at the same time.

[0048] The present invention may be a system, method and / or computer program product at any possible level of integrated technical detail. The computer program product may include a computer-readable storage medium (or multiple media) having computer-readable program instructions thereon for causing a processor to perform various aspects of the present invention.

[0049] A computer readable storage medium may be a tangible device that can retain and store instructions used by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, 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, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device such as a punch card or a raised structure in a groove on which instructions are recorded, and any suitable combination of the above. A computer readable storage medium, as used herein, should not be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted by a wire.

[0050] The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium within the corresponding computing / processing device.

[0051] The computer-readable program instructions for performing the operation of the present 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 any combination of one or more programming languages ​​and process programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as an independent 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 by 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., by using the Internet of an Internet service provider). In certain embodiments, the electronic circuit including, for example, a programmable logic circuit, a field programmable gate array (FPGA) or a programmable logic array (PLA) may execute the computer-readable program instructions by utilizing the state information of the computer-readable program instructions to personalize the electronic circuit, thereby performing aspects of the present invention.

[0052] Various aspects of the present invention are described herein with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It is understood that each block of the flowchart illustration and / or block diagram, and the combination of blocks in the flowchart illustration and / or block diagram, can be implemented by computer-readable program instructions.

[0053] These computer-readable program instructions may be provided to a processor of a computer or other programmable data processing device to produce a machine so that the instructions executed by the processor of the computer or other programmable data processing device create instructions for implementing the flowcharts and / or block diagrams. Figure 1 These computer-readable program instructions may also be stored in a computer-readable storage medium capable of booting a computer, a programmable data processing device and / or other device that operates in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes a manufactured product that includes instructions that implement aspects of the functions / actions specified in the flowchart and / or block diagram blocks.

[0054] Computer readable program instructions may also be loaded into a computer, other programmable data processing device, or other device to cause a series of operating steps to be performed on the computer, other programmable devices or other devices for producing a computer-implemented process, so that the instructions executed on the computer, other programmable device or other device implement the functions / actions specified in the flowchart and / or block diagram blocks.

[0055] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the system, method and computer program product according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, segment or portion of an instruction, which includes one or more executable instructions for implementing a specified logical function. In some optional implementations, the functions indicated in the block may occur outside the order indicated in the figure. For example, in fact, two blocks shown in succession can be completed as a step, and depending on the functions involved, they can be executed concurrently, substantially concurrently, in a partially or fully time-overlapping manner, or sometimes these blocks can be executed in reverse order. It will also be noted that each block of the block diagram and / or flowchart illustration, as well as the combination of blocks in the block diagram and / or flowchart illustration, can be implemented by a dedicated hardware-based system that performs a specified function or action or performs a combination of dedicated hardware and computer instructions.

[0056] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, apparatuses (devices) and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0057] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0058] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

Claims

1. An LED backlight driving system, characterized in that: The LED driving system comprises: A backlight timing controller and at least one LED driver link; The LED driving link includes a plurality of LED driving chips; the plurality of 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 a plurality of LED driver channel pins, and the LED driver channel pins are used to connect LED light-emitting elements to control the LED light-emitting elements to emit light; The data frame sent by the backlight timing controller to the LED driver link includes an echo data bit; When the LED driver chip receives the echo data bit, the LED driver chip determines whether to write the echo information into the echo data bit according to its own driving state.

2. The LED backlight driving system according to claim 1, characterized in that: The echoed information includes but is not limited to LED drive voltage undervoltage information, chip operating temperature information or drive status error information.

3. The LED backlight driving system according to claim 2, characterized in that: The LED driving voltage undervoltage information is the physical sequence position of the current LED driving chip on the LED driving link.

4. The LED backlight driving system according to claim 2, characterized in that: 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 on the LED driver link.

5. The LED backlight driving system according to claim 2, characterized in that: The driving state error information is used to express the short circuit state information, open circuit state information or over-temperature protection state information of the LED driving channel pin of the LED driving chip.

6. The LED backlight driving system according to claim 1, characterized in that: Each of the LED driver chips is provided with a first data transmission port and a second data transmission port; the serial communication link means that the first data transmission port of each LED driver chip is connected to the second data transmission port of the LED driver chip of the previous level adjacent to the LED driver chip, and the second data transmission port of each LED driver chip is connected to the first data transmission port of the LED driver chip of the next level adjacent to the LED driver chip, and the first LED driver chip in the LED driver link is connected to the transmission port of the backlight timing controller Bcon.

7. The LED backlight driving system according to claim 1, characterized in that: 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.

8. The LED backlight driving system according to claim 1, characterized in that: 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 unconnected or multiplexed as a status output port.

9. The LED backlight driving system according to claim 1, characterized in that: The data frame sent by the backlight timing controller to the LED driving link includes a frame header bit, and the frame header bit is used to identify the physical sequence position of the driving chip that currently receives the data frame on the serial communication link.

10. An LED backlight panel, comprising a plurality of LED driving units and a plurality of LED light groups, wherein the LED driving unit is formed by the LED backlight driving system according to any one of claims 1 to 9.

Images