Light emitting diode display panel and its driving system, and display device

Abstract

The present application relates to a light-emitting diode display panel and its driving system and display device. The light-emitting diode display panel includes a plurality of light-emitting diode display modules that are driven independently of each other, and the signals between the light-emitting diode display modules are realized through the coupling of the second excitation coil and the third excitation coil between the modules, so as to adapt to the light-emitting diode display panel structure that is independently driven by a plurality of light-emitting diode display modules. The light-emitting diode display modules can be tightly fitted and seamlessly spliced, and when replacement is required due to a lamp bead failure, only the corresponding light-emitting diode display module needs to be replaced. In addition, the above scheme uses low-voltage differential signals for data transmission between boards, and achieves a larger bandwidth with fewer wiring harnesses on the substrate, solving the problem of high output transmission cost caused by large COB data load at a very low cost.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a light emitting diode display panel and a driving system and a display device thereof. Background Art

[0002] LED (Light-Emitting Diode) display is a device that encapsulates LED on a substrate and uses LED light to display text, images, videos and other information. LED display integrates microelectronics technology, computer technology, and information processing, and has the advantages of bright colors, wide dynamic range, high brightness, long life, stable and reliable operation, etc. LED display is widely used in commercial media, cultural performance market, sports stadiums, information dissemination, news release, securities trading, etc., and can meet the needs of different environments.

[0003] At present, there are two main technical forms of LED display screen packaging, one is SMD (Surface Mounted Devices) packaging, and the other is COB (Chips on Board) packaging. COB packaging is a semiconductor packaging process that adheres the chip to the interconnect substrate with conductive or non-conductive glue, and then performs wire bonding to achieve its electrical connection. In simple terms, it is to directly mount the light-emitting chip on the PCB (Printed Circuit Board) without the need for a bracket and solder pins. Compared with the SMD method, COB packaging omits the processes of making LED chips into lamp beads and reflow soldering. The light-emitting chip can be directly assembled on the PCB substrate, without the limitation of the size of the packaged device, and a smaller dot pitch arrangement can be achieved, thereby displaying high-definition content.

[0004] Compared with SMD packaging, COB packaging can accommodate denser and smaller lamp beads under the same substrate size. The pixel density of COB packaging type LED display can be much higher than that of SMD packaging type LED display, which means that the amount of data that can be carried in COB packaging technology can be dozens of times that of SMD packaging. Therefore, the data transmission line bandwidth used in COB packaging type LED display is wider, or there are more wiring harnesses, and the cost of data transmission and distribution solutions for the screen is higher. Summary of the invention

[0005] Based on this, it is necessary to provide a light emitting diode display panel and its driving system and display device to address the problem of high data transmission cost of traditional COB packaging type LED display screens.

[0006] A driving system for a light emitting diode display panel, the light emitting diode display panel comprises a plurality of independently driven light emitting diode display modules, the driving system comprises: a first driving device, the power supply end of the first driving device is connected to a current source, and the ground end of the first driving device is grounded; a first excitation coil, the first differential signal output end of the first driving device is connected to the first end of the first excitation coil, and the second differential signal output end of the first driving device is connected to the second end of the first excitation coil; a second excitation coil is arranged in the light emitting diode display module, and the second excitation coil in the first-stage light emitting diode display module is coupled to the first excitation coil, and the second excitation coil not in the first-stage light emitting diode display module is coupled to the upper-stage light emitting diode display module. The third excitation coil of the light emitting diode display module is coupled; a first receiving device is arranged in the light emitting diode display module, the first input end of the first receiving device is connected to the first end of the second excitation coil in the light emitting diode display module of the same level, the second input end of the first receiving device is connected to the second end of the second excitation coil in the light emitting diode display module of the same level, and the output end of the first receiving device is connected to the lamp bead array of the light emitting diode display module of the same level; a third excitation coil is arranged in the light emitting diode display module, the first end and the second end of the third excitation coil are respectively connected to the first end and the second end of the second excitation coil of the light emitting diode display module of the same level, and the third excitation coil is coupled with the second excitation coil of the light emitting diode display module of the next level.

[0007] In one embodiment, the driving system also includes a second receiving device and a second driving device, the input end of the second driving device is connected to the lamp bead array of the same-level LED display module, the first output end of the second driving device is connected to the first end of the second excitation coil in the same-level LED display module, the second output end of the second driving device is connected to the second end of the second excitation coil in the same-level LED display module, the first input end of the second receiving device is connected to the first end of the first excitation coil, the second input end of the second receiving device is connected to the second end of the first excitation coil, and the output end of the second receiving device is connected to an external controller.

[0008] In one embodiment, the first driving device includes a first switching device, a second switching device, a third switching device and a fourth switching device, the first end of the first switching device is connected to the first end of the third switching device and the common end is connected to a current source, the second end of the first switching device is connected to the first end of the second switching device and the common end is connected to the first end of the first excitation coil, the second end of the third switching device is connected to the first end of the fourth switching device and the common end is connected to the second end of the first excitation coil, the second end of the second switching device is connected to the second end of the fourth switching device and the common end is grounded, and the control ends of the first switching device, the second switching device, the third switching device and the fourth switching device are respectively connected to external controllers.

[0009] In one embodiment, the first receiving device includes a resistor and a receiver, the first input end of the receiver is connected to the first end of the resistor, and the common end is connected to the first end of the second excitation coil of the same-level LED display module, the second input end of the receiver is connected to the second end of the resistor, and the common end is connected to the second end of the second excitation coil of the same-level LED display module, and the output end of the receiver is connected to the lamp bead array of the same-level LED display module.

[0010] In one embodiment, the first driving device includes a driver and a first micro control unit, the power supply terminal of the driver is connected to a current source, the ground terminal of the driver is grounded, the first output terminal of the driver is connected to the first micro control unit and the common terminal is connected to the first end of the first excitation coil, and the second output terminal of the driver is connected to the first micro control unit and the common terminal is connected to the second end of the first excitation coil.

[0011] In one embodiment, the first receiving device includes a second micro control unit, a resistor and a receiver, wherein the first input end of the receiver is connected to the first end of the resistor, and the common end is connected to the second micro control unit and the first end of the second excitation coil of the same-level light-emitting diode display module; the second input end of the receiver is connected to the second end of the resistor, and the common end is connected to the second micro control unit and the second end of the second excitation coil of the same-level light-emitting diode display module, and the output end of the receiver is connected to the lamp bead array of the same-level light-emitting diode display module.

[0012] In one embodiment, the first switch device, the second switch device, the third switch device and the fourth switch device are all transistors, field effect transistors or insulated gate bipolar transistors.

[0013] In one embodiment, the number of the first driving devices is more than two.

[0014] A light emitting diode display panel comprises the above-mentioned driving system.

[0015] A display device comprises the above-mentioned light emitting diode display panel.

[0016] The above-mentioned light-emitting diode display panel and its driving system and display device, the light-emitting diode display panel includes a plurality of light-emitting diode display modules that are driven independently of each other, and the signals between each light-emitting diode display module are realized through the coupling of the second excitation coil and the third excitation coil between the modules, so as to adapt to the light-emitting diode display panel structure that is independently driven by a plurality of light-emitting diode display modules. The light-emitting diode display modules can be tightly fitted and seamlessly spliced, and when replacement is required due to a lamp bead failure, only the corresponding light-emitting diode display module needs to be replaced. In addition, the above-mentioned scheme uses low-voltage differential signals for data transmission between boards, and realizes a larger bandwidth with fewer wiring harnesses on the substrate, solving the problem of high output transmission cost caused by large COB data load at a very low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a schematic structural diagram of a driving system of a light emitting diode display panel in one embodiment;

[0019] Figure 2 This is a schematic diagram of the data transmission process of a drive system in one embodiment;

[0020] Figure 3 This is a schematic diagram of an exploded structure of a double-layer light emitting diode display module in one embodiment;

[0021] Figure 4 This is a schematic diagram of the first surface structure of a single-layer light emitting diode display module in one embodiment;

[0022] Figure 5 This is a schematic diagram of the second surface structure of a single-layer light-emitting diode display module in one embodiment;

[0023] Figure 6 It is a structural schematic diagram of a driving system in another embodiment;

[0024] Figure 7 It is a structural schematic diagram of a driving system in another embodiment;

[0025] Figure 8 A schematic diagram of the structure of a driving system in yet another embodiment;

[0026] Fig. 9 Schematic diagram of the structure of a drive system in another embodiment. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0028] See also Figure 1 , a driving system of a light emitting diode display panel, the light emitting diode display panel includes a plurality of independently driven light emitting diode display modules, the driving system includes: a first driving device 10, the power supply end of the first driving device 10 is connected to a current source, and the ground end of the first driving device 10 is grounded; a first excitation coil 20, the first differential signal output end of the first driving device 10 is connected to the first end of the first excitation coil 20, and the second differential signal output end of the first driving device 10 is connected to the second end of the first excitation coil 20; a second excitation coil 30, which is arranged in the light emitting diode display module, and the second excitation coil 30 in the first-level light emitting diode display module is coupled to the first excitation coil 20, and the second excitation coil 30 not in the first-level light emitting diode display module is coupled to the upper-level light emitting diode The first receiving device 50 is arranged in the light-emitting diode display module, the first input end of the first receiving device 50 is connected to the first end of the second excitation coil 30 in the light-emitting diode display module at the same level, the second input end of the first receiving device 50 is connected to the second end of the second excitation coil 30 in the light-emitting diode display module at the same level, and the output end of the first receiving device 50 is connected to the lamp bead array of the light-emitting diode display module at the same level; the third excitation coil 40 is arranged in the light-emitting diode display module, the first end and the second end of the third excitation coil 40 are respectively connected to the first end and the second end of the second excitation coil 30 of the light-emitting diode display module at the same level, and the third excitation coil 40 is coupled with the second excitation coil 30 of the light-emitting diode display module at the next level.

[0029] Specifically, the output end of the first driving device 10 includes a first differential signal output end and a second differential signal output end. The first driving device 10 uses two wires (i.e., differential signal wires) to transmit a signal and is driven by a current source. The light-emitting diode display panel of this embodiment is assembled using a plurality of independently driven light-emitting diode display modules, that is, each light-emitting diode display module includes a driving chip and a lamp bead array matching the load capacity of the driving chip. The display driving operation of the lamp bead array in the corresponding light-emitting diode display module can be realized through the driving chip.

[0030] Among them, the first-level LED display module is the LED display module into which the differential signal output by the first driving device 10 first enters. Each LED display module is correspondingly provided with a second excitation coil 30 and a third excitation coil 40, wherein the second excitation coil 30 of the first-level LED display module is coupled with the first excitation coil 20, receives the signal output by the first driving device 10 for the lamp bead array display drive related signal, and then transmits it to the first receiving device 50 connected thereto for receiving, and finally sends it to the lamp bead array through the first receiving device 50 to realize the display drive of the lamp bead. At the same time, the signal received by the second coupling coil is also synchronously transmitted to the third excitation coil 40 in the same-level LED display module, and finally transmits it to the next-level LED display module through the coupling between the third excitation coil 40 and the second excitation coil 30 of the next-level LED display module, so as to realize the cross-board transmission of the signal.

[0031] It should be pointed out that each light-emitting diode display module includes a driver chip and a lamp bead array that matches the load capacity of the driver chip. Specifically, the load capacity of a driver chip can be matched with a lamp bead array. At this time, the same number of driver chips and lamp bead arrays can be set simultaneously in the light-emitting diode display module. Each driver chip drives a corresponding lamp bead array to achieve a match between the number of lamp beads in the bead array in the entire light-emitting diode display module and the load capacity of the driver chip.

[0032] In another embodiment, the load capacity of m driver chips can be matched with n lamp bead arrays, wherein m and n are both positive integers greater than 1, and m and n are not equal. That is, in this embodiment, in the same independently driven light emitting diode display module, m driver chips and n lamp bead arrays can be set, and the n lamp bead arrays can be driven by the m driver chips at the same time, so that the number of lamp beads in the bead array in the entire light emitting diode display module matches the load capacity of the driver chip.

[0033] In a more detailed embodiment, please refer to Figure 2, the signal transmission of the first-level light-emitting diode display module is used as an example for explanation. The data related to the display drive is generated from the data output front stage, and is converted from the TTL level signal to the LVDS (low voltage differential) signal in the first driving device 10, and is transmitted from the two differential signal output ends of the first driving device 10, and is induced by the first excitation coil 20, and the high-frequency data signal is transmitted to the first light-emitting diode display module. The first receiving device 50 of the first-level light-emitting diode display module determines whether to receive the data. If it is received, the circuit is turned on, and the high-frequency signal will be output through the output end on the first receiving device 50, and then the LVDS signal is converted into a TTL signal and sent to the lamp bead array of the display module to complete the transmission of the entire data. If the MCU determines that the data is not received, the receiving circuit will not be turned on, and the high-frequency data will continue to be transmitted to the next-level light-emitting diode display module in the form of LVDS through the coupling induction of the second excitation coil 30 and the third excitation coil 40 between the two display modules.

[0034] It should be noted that Figure 2 The embodiment shown only uses the conduction position of the first-level light-emitting diode display module. In actual applications, once the data is turned on at the previous receiving end, it will naturally be transmitted to the next receiving end. The second excitation coil 30 and the third excitation right are connected in series through the splicing cascade of the display module, step by step, to create a high-speed LVDS data transmission channel. On this channel, the data from the first driving device 10 will be quickly transmitted to the second excitation coil 30 and its first receiving device 50 on each display module. The first receiving device 50 only needs to analyze and judge whether it needs to receive the data.

[0035] Specifically, assuming that the data is divided into display module 1, display module 2, and display module 3, when transmitting the data of display module 1, the second excitation coil 30 on display module 2 and display module 3 will also receive the same data as display module 1, but whether to further transmit to the corresponding lamp bead array can be controlled by the first receiving device 50. Similarly, when transmitting the data of display module 2 or display module 3, the data will also pass through display module 1, and display module 1 can also choose to receive or not receive.

[0036] The excitation coil transmits signals in a high-frequency wireless manner at a short distance, which is designed based on the module splicing characteristics of the LED display screen. The display module will be accurately positioned at the splicing position, and the two display modules will fit tightly. When the module splicing is completed, the corresponding positioning of the coil is accurate and the distance is close, which can transmit data with extremely high energy efficiency. This embodiment uses low-voltage differential signals for data transmission. Compared with the existing LED module data transmission solution, it has stronger data carrying capacity and strong anti-interference ability.

[0037] In the data distribution scheme of the embodiment, the LVDS data signal is transmitted to the next-level display module between the boards by induction of the excitation coil. This is an adaptation design based on the splicing characteristics of the light-emitting diode display module. Specifically, the light-emitting diode display module is tightly fitted at the splicing seam position, and the flatness of the splicing is required to be extremely high. This means that the distance between the two boards is extremely small and the positioning accuracy is high. This feature creates good conditions for the coupling of the excitation coil. Furthermore, if the excitation coil induced current is not used between the boards for data transmission, it is necessary to directly connect several signal lines between the boards. When disassembling and assembling the modules, these cross-board signal lines will involve the display module, affecting the disassembly and assembly, and also affecting the quality of the module installation and the quality of data transmission.

[0038] By utilizing this feature, the cross-board data communication of the COB packaged LED display screen in this embodiment mainly transmits display data by induction of a high-frequency excitation coil. Data is wirelessly transmitted between boards at high speed in the form of LVDS. For the entire display screen, it is divided into several driving ends (that is, it has multiple first driving devices 10), and the driving end can carry one or more receiving ends (that is, it can carry at least one first receiving device 50). The receiving end is installed on the display module, which means that one driving end can carry one or more display modules.

[0039] It should be noted that the specific structure of the independently driven LED display module is not unique. In one embodiment, it can be a double-layer structure type LED display module. In another embodiment, it can be a single-layer structure type LED display module.

[0040] For example, see Figure 3 The light emitting diode display module includes a lamp bead substrate 91, a driving substrate 92, a lamp bead array 93 and a driving chip 94. The lamp bead array 93 is arranged on the lamp bead substrate 91, and the driving chip 94 is arranged on the first surface of the driving substrate 92. A solder joint is arranged on the second surface of the driving substrate 92 opposite to the first surface. The row driving pins and the column driving pins of the driving chip 94 are respectively connected to the lamp bead array 93. The number of lamp beads in the lamp bead array 93 matches the load capacity of the driving chip 94.

[0041] The driving chip 94 and the driving substrate 92 constitute the driving layer, while the lamp bead array 93 and the lamp bead substrate 91 constitute the display lamp bead layer, and the light emitting diode display module adopts a double-layer structure design. The lamp bead array 93 and the driving chip 94 are set on different substrates, that is, the lamp bead substrate 91 and the driving substrate 92, and then the driving chip 94 and the lamp bead array 93 are cross-layer connected to obtain the light emitting diode display module. A solder joint is set on the second surface of the driving substrate 92, so that the entire light emitting diode display module can be directly welded to the substrate of the light emitting diode display panel through the solder joint to form a light emitting diode display panel. The driving substrate 92 is divided into two sides, the front side (that is, the first surface) is mainly a constant current output driving chip 94, and in another embodiment, it may also include a constant current regulating resistor. The driving chip 94 can output all the display signals required by the lamp bead. The back side (that is, the second surface) is a plurality of welding connection nodes, which can be BGA ball solder joints in a more detailed embodiment. In this way, the light emitting diode display module can be directly packaged on the substrate by heating and welding like the current chip packaging.

[0042] Furthermore, in one embodiment, the light emitting diode display module may further include a connection layer 95, which is disposed between the lamp bead substrate 91 and the driving substrate 92, and the row driving pins and the column driving pins of the driving chip 94 are respectively connected to the lamp bead array 93 through the connection layer 95. Furthermore, in one embodiment, the light emitting diode display module further includes a surface sealing layer 96, which is disposed on the lamp bead array 93.

[0043] Or in another embodiment, please refer to Figure 4-Figure 5 , the light emitting diode display module includes an integrated substrate 97, a lamp bead array 93 and a driving chip 94. The lamp bead array 93 is arranged on the first surface of the integrated substrate 97, and the driving chip 94 is arranged on the second surface of the integrated substrate 97. The first surface and the second surface are arranged opposite to each other. The integrated substrate 97 is provided with a through hole. The row driving pins and the column driving pins of the driving chip 94 are respectively connected to the lamp bead array 93 through the through hole. The number of lamp beads in the lamp bead array 93 matches the load capacity of the driving chip 94. The lamp bead array 93 and the driving chip 94 are arranged on two opposite surfaces of the same substrate to form a single-layer structure light emitting diode display module. The single-layer light emitting diode display module only uses a single PCB board (i.e., substrate). The front side (the first surface) is used as the packaging layer of the display lamp beads, and the back side (i.e., the second surface) is used as the packaging layer of the driving chip 94, and also as the installation position of the connecting pins. Compared with the above-mentioned double-layer structure, the hierarchical relationship is reduced. The lamp bead array 93 directly goes from the through hole to the back side of the PCB and connects to the driving chip 94.

[0044] See also Figure 6In one embodiment, the driving system further includes a second receiving device 70 and a second driving device 60, the input end of the second driving device 60 is connected to the lamp bead array 93 of the same-level LED display module, the first output end of the second driving device 60 is connected to the first end of the second excitation coil 30 in the same-level LED display module, the second output end of the second driving device 60 is connected to the second end of the second excitation coil 30 in the same-level LED display module, the first input end of the second receiving device 70 is connected to the first end of the first excitation coil 20, the second input end of the second receiving device 70 is connected to the second end of the first excitation coil 20, and the output end of the second receiving device 70 is connected to an external controller.

[0045] Specifically, in the LED display screen, there are two corresponding relationships between the excitation coils. The first is the correspondence between the driving end and the display module, that is, the first excitation coil 20 and the second excitation coil 30 in the first-level light-emitting diode display module. Here, the driving end transmits the converted high-frequency LVDS signal to the module through the excitation coil, which is the correspondence between the driving end coil and the module end coil. The second is the correspondence between the two spliced ​​display modules, that is, the third excitation coil 40 and the second excitation coil 30 in the next-level light-emitting diode display module. The LVDS signal introduced into the module will continue to be transmitted step by step along the excitation coil on the module.

[0046] However, on this transmission path, data is transmitted unidirectionally without feedback. In some application scenarios, based on the LVDS communication display module to achieve two-way data communication, combined with the structural characteristics of the light-emitting diode display module, the return data rate, including the data content, can be less than and slower than the direct data. This is because the various functions that need to be realized through the return transmission are actually very simple and do not need to be very fast. Compared with the LVDS data transmission mode, it can fully meet the requirements of data return.

[0047] In this embodiment, a half-duplex structure type driving system is adopted, a second driving device 60 is provided at the light-emitting diode display module, and a second receiving device 70 is connected at the first excitation coil 20. When the first driving device 10 and the first receiving device 50 perform data transmission and the display driving control of the light-emitting diode display panel is performed, the communication between the second driving device and the second receiving device 70 is cut off. When the second driving device 60 and the second receiving device 70 perform feedback data back transmission, the communication between the first driving device 10 and the first receiving device 50 is cut off. That is, the time-division multiplexing of the half-duplex structure driving system of this embodiment is used to realize the bidirectional transmission of data between the boards.

[0048] It should be noted that the specific structure of the first driving device 10 is not unique. In one embodiment, please refer to Figure 7The first driving device 10 includes a first switching device Q1, a second switching device Q2, a third switching device Q3 and a fourth switching device Q4, a first end of the first switching device Q1 is connected to a first end of the third switching device Q3 and a common end is connected to a current source, a second end of the first switching device Q1 is connected to a first end of the second switching device Q2 and a common end is connected to a first end of the first excitation coil 20, a second end of the third switching device Q3 is connected to a first end of the fourth switching device Q4 and a common end is connected to a second end of the first excitation coil 20, a second end of the second switching device Q2 is connected to a second end of the fourth switching device Q4 and a common end is grounded, and control ends of the first switching device Q1, the second switching device Q2, the third switching device Q3 and the fourth switching device Q4 are respectively connected to external controllers.

[0049] Specifically, when the second switch device Q2 and the third switch device Q3 are turned on and the first switch device Q1 and the fourth switch device Q4 are turned off under the action of the external controller, the current of the current source flows to the first excitation coil 20 through the second end of the third switch device Q3, flows back to the second switch device Q2 through the first excitation coil 20, and is grounded through the second switch device Q2 to form a closed loop. When the current flows through the first excitation coil 20, an induced current will be generated on the second excitation coil 30 of the first-level light-emitting diode display module, and the flow direction of the induced current is opposite to the current direction on the first excitation coil 20. After the induced current flows into the first receiving device 50, a certain voltage drop will be generated on the first receiving device 50. At this time, the voltage at the second end of the first receiving device 50 is higher than the voltage at the first end, and the output of the first receiving device 50 is a high level.

[0050] When the second switch device Q2 and the third switch device Q3 are disconnected and the first switch device Q1 and the fourth switch device Q4 are turned on under the action of the external controller, the current of the current source flows to the first excitation coil 20 through the second end of the first switch device Q1, flows back to the fourth switch device Q4 through the first excitation coil 20, and is grounded through the fourth switch device Q4 to form a closed loop. When the current flows through the first excitation coil 20, an induced current will be generated on the second excitation coil 30 of the first-level light-emitting diode display module, and the flow direction of the induced current is opposite to the current direction on the first excitation coil 20. After the induced current flows into the first receiving device 50, a certain voltage drop will be generated in the first receiving device 50. At this time, the voltage at the first end of the first receiving device 50 is higher than the voltage at the second end, and the output of the first receiving device 50 is a low level. Therefore, the required data transmission function is completed through the low-voltage differential signal, and each excitation coil can be split or bonded through a specific winding method. This feature is applied to the splicing module, so that the module is not constrained by the wire harness and cross-board data transmission can be achieved in a wireless form.

[0051] Accordingly, in one embodiment, please refer to Figure 7 The first receiving device 50 includes a resistor 51 and a receiver 52, the first input end of the receiver 52 is connected to the first end of the resistor 51, and the common end is connected to the first end of the second excitation coil 30 of the same-level light-emitting diode display module, the second input end of the receiver 52 is connected to the second end of the resistor 51, and the common end is connected to the second end of the second excitation coil 30 of the same-level light-emitting diode display module, and the output end of the receiver 52 is connected to the lamp bead array 93 of the same-level light-emitting diode display module.

[0052] Specifically, in the solution of this embodiment, the first receiving device 50 includes a resistor 51 and a receiver 52. When the current flows through the first excitation coil 20, an induced current will be generated on the second excitation coil 30 of the first-level light-emitting diode display module. When the induced current acts on the resistor 51 of the first receiving device 50, a certain voltage drop will be generated. Depending on the flow direction of the induced current, the voltage at the first end of the receiver 52 will be greater than the voltage at the second end, and the voltage at the second end will be greater than the voltage at the first end. At this time, a high level and a low level will be output respectively.

[0053] It can be understood that the specific structures of the first driving device 10 and the first receiving device 50 can be applied to the driving system of the light emitting diode display panel with unidirectional data transmission in the above embodiment, or the driving system of the light emitting diode display panel of the half-duplex type. Further, in one embodiment, the specific structure of the second driving device 60 is similar to the specific structure of the first driving device 10, and the specific structure of the second receiving device 70 is similar to the specific structure of the first receiving device 50, which will not be repeated here.

[0054] For further information, see Figure 8 In one embodiment, the first driving device 10 includes a driver 11 and a first micro control unit 12, the power supply end of the driver 11 is connected to the current source, the ground end of the driver 11 is grounded, the first output end of the driver 11 is connected to the first micro control unit 12 and the common end is connected to the first end of the first excitation coil 20, and the second output end of the driver 11 is connected to the first micro control unit 12 and the common end is connected to the second end of the first excitation coil 20.

[0055] Specifically, the specific structure of the driver 11 is not unique. In one embodiment, the driver 11 may include a first switching device, a second switching device, a third switching device and a fourth switching device. The first end of the first switching device is connected to the first end of the third switching device, and the common end is connected to the current source, the second end of the first switching device is connected to the first end of the second switching device and the common end is connected to the first micro control unit 12 and the first end of the first excitation coil 20, the second end of the third switching device is connected to the first end of the fourth switching device, and the common end is connected to the first micro control unit 12 and the second end of the first excitation coil 20, the second end of the second switching device is connected to the second end of the fourth switching device and the common end is grounded, and the control ends of the first switching device, the second switching device, the third switching device and the fourth switching device are respectively connected to external controllers.

[0056] In the scheme of this embodiment, a driver 11 is formed by combining a bridge structure of a first switch device, a second switch device, a third switch device and a fourth switch device. In the scheme of this embodiment, in addition to the driver 11, the first driving device 10 also includes a first micro control unit 12. The first micro control unit 12 is arranged between the driver 11 and the first excitation coil 20, and is used to monitor the data signal returned by the light-emitting diode display module and record it.

[0057] For further information, please refer to Figure 8 In one embodiment, the first receiving device 50 includes a second micro control unit 53, a resistor 51 and a receiver 52, wherein the first input end of the receiver 52 is connected to the first end of the resistor 51, and the common end is connected to the second micro control unit 53 and the first end of the second excitation coil 30 of the same-level light-emitting diode display module; the second input end of the receiver 52 is connected to the second end of the resistor 51, and the common end is connected to the second micro control unit 53 and the second end of the second excitation coil 30 of the same-level light-emitting diode display module, and the output end of the receiver 52 is connected to the lamp bead array 93 of the same-level light-emitting diode display module.

[0058] Specifically, the scheme connects a second micro-control unit 53 in parallel at the receiving end of each display module, which can be regarded as a load different from the resistor 51, and its voltage drop is much smaller than the resistor 51. Then, when the second micro-control unit 53 is turned on, the current will preferentially pass through the second micro-control unit 53, resulting in a different voltage drop. This voltage drop is much smaller than the voltage drop of the resistor 51, so for the first excitation level coil, there will be a significantly different current change. Specifically, due to the reduction of the load, the current will also decrease accordingly. The second micro-control unit 53 part can be understood as a circuit without a voltage drop, while the two ends of the resistor 51 have a certain voltage drop. When the second micro-control unit 53 is not turned on, the voltage drop of the resistor 51 becomes higher. By switching the voltage drop, the circuit influence on the first excitation coil 20 is realized, and simple data content is fed back to the first coil.

[0059] The solution of this embodiment provides a bidirectional data transmission solution different from the above half-duplex structure, that is, a return solution during discharge. The display-related data is transmitted from the first driving device 10 and transmitted to the display module through the first excitation coil and the second excitation coil 30. The data can be transmitted instantaneously on the entire channel. Fig. 9 , each module only needs to combine its own needs to receive the corresponding data to the display bead array 93, and then convert it into TTL format to realize display driving. When data feedback is required, it is necessary to transmit it through the second micro control unit 53 and the first micro control unit 12. It should be noted that when the second micro control unit 53 of any module on the connected module is turned on, it can directly affect the first drive device 10, so that the data is not returned in a hierarchical manner, but directly returned from any module to the first drive device 10. In one embodiment, the feedback signals of different modules can be distinguished by encoding in the header of the feedback data.

[0060] Through the above solution, at least the following three applications can be realized:

[0061] Data correction: During the data transmission process, data correction is required to determine whether the data received on a single display module is complete and without loss. The correction process is to input a specific check bit at the end of each data transmission, and the control circuit on the module verifies whether the received data is complete based on the check bit. If the data is received correctly and completely, it will be returned to the first drive device 10, and the current module has completed receiving the data, and now transmits the display data required by the next module. If the data reception is incomplete, it is necessary to feedback to the first drive device 10 that the current module data reception is incomplete and needs to be resent. At this time, there is a need for return data, which is to tell the first drive device 10 which level of the light-emitting diode display module is currently receiving data and how complete the reception is. Through a specific communication protocol, data return methods such as half-duty and discharge can be used to return specific codes to let the first drive device know the information of the current receiving module, thereby completing the function of self-correction of data transmission.

[0062] Automatic module identification (automatic screen matching): The light-emitting diode display panel in this application is composed of several light-emitting diode display modules spliced ​​together. Several first drive devices 10 are required on the screen, and the number of display modules that each first drive device 10 can carry is limited, and the number of display modules composed of the entire display panel is uncertain. In most cases, the modules carried by different first drive devices 10 have irregular data transmission paths. Due to the random arrangement of the module positions, when data is transmitted, if it is transmitted in sequence from the first-level display module to the last-level display, the picture displayed on the screen is messy, like a shuffled puzzle. To address this problem, the conventional method requires manual debugging to solve it, that is, to understand the data channel connection method of each display panel, and arrange the messy pictures one by one, so that when the data is directly transmitted, it can form a complete display panel with the correct order. And this debugging process is nothing more than sorting out the installation position relationship of each module, including the wiring relationship of the channel, and then rearranging the order of sending data.

[0063] However, through the above solution, two-way data communication can be achieved between the boards, and the current position relationship can be determined from each other, and the position relationship can be transmitted back to the first driving device 10, so as to automatically adjust the data transmission data and realize automatic recognition of the module. When the screen is powered on, it can automatically confirm the current connection relationship and the order of data transmission, and automatically arrange the disordered display screen into a complete display screen.

[0064] Impedance adaptive identification: The scheme of this embodiment adopts low-voltage differential signal transmission data, and there is also an excitation coil conversion step between the boards. During the data transmission process, current loss will definitely be generated due to line loss and electromagnetic induction, so that the current will eventually remain in each module, and there will be slight differences. This difference can be obtained by detecting the two data lines on the display module (that is, the communication line between the second excitation coil 30 and the third excitation coil 40 in the same level LED display module).

[0065] It can be understood that the type of switch device in the first driving device 10 is not unique. In one embodiment, the first switch device Q1, the second switch device Q2, the third switch device Q3 and the fourth switch device Q4 are all transistors, field effect transistors or insulated gate bipolar transistors. In other embodiments, other types of switch devices can be used as long as the corresponding bridge arm switch circuit can be constructed and the low voltage differential signal can be output for data transmission.

[0066] In one embodiment, the number of the first driving devices 10 is more than two.

[0067] Specifically, in actual application scenarios, hundreds, thousands or even more LED display modules are often required to be spliced ​​in an LED display panel, and the driving capability of one first driving device 10 is limited, and the driving operation of all LED display modules cannot be achieved through one first driving device 10. Therefore, in this embodiment, more than two first driving devices 10 are provided, and each first driving device 10 can provide display-related data for multiple LED display modules, thereby completing the driving of the entire LED display panel.

[0068] The driving system of the above-mentioned LED display panel, the LED display panel includes a plurality of LED display modules that are driven independently of each other, and the signals between the respective LED display modules are realized through the coupling of the second excitation coil 30 and the third excitation coil 40 between the modules, so as to adapt to the structure of the LED display panel that is independently driven by a plurality of LED display modules. The LED display modules can be tightly fitted and seamlessly spliced, and when replacement is required due to a lamp bead failure, only the corresponding LED display module needs to be replaced. In addition, the above-mentioned scheme uses low-voltage differential signals for data transmission between boards, and realizes a larger bandwidth with fewer wiring harnesses on the substrate, solving the problem of high output transmission cost caused by large COB data carrying capacity at a very low cost.

[0069] A light emitting diode display panel comprises the above-mentioned driving system.

[0070] Specifically, the driving system of the light-emitting diode display panel is as shown in the above-mentioned embodiments and the accompanying drawings. The output end of the first driving device 10 includes a first differential signal output end and a second differential signal output end. The first driving device 10 uses two wires (i.e., differential signal wires) to transmit a signal and is driven by a current source. The light-emitting diode display panel of this embodiment is assembled using a plurality of independently driven light-emitting diode display modules, that is, each light-emitting diode display module includes a driving chip 94 and a lamp bead array 93 matching the load capacity of the driving chip 94. The display driving operation of the lamp bead array 93 in the corresponding light-emitting diode display module can be realized through the driving chip 94.

[0071] Among them, the first-level LED display module is the LED display module into which the differential signal output by the first driving device 10 first enters. Each LED display module is correspondingly provided with a second excitation coil 30 and a third excitation coil 40, wherein the second excitation coil 30 of the first-level LED display module is coupled with the first excitation coil 20, receives the signal output by the first driving device 10 for display driving of the lamp bead array 93, and then transmits it to the first receiving device 50 connected thereto for receiving, and finally sends it to the lamp bead array 93 through the first receiving device 50 to realize the display driving of the lamp bead. At the same time, the signal received by the second coupling coil is also synchronously transmitted to the third excitation coil 40 in the same-level LED display module, and finally transmits it to the next-level LED display module through the coupling between the third excitation coil 40 and the second excitation coil 30 of the next-level LED display module, so as to realize the cross-board transmission of the signal.

[0072] The above-mentioned light-emitting diode display panel includes a plurality of light-emitting diode display modules that are driven independently of each other, and the signals between the light-emitting diode display modules are realized through the coupling of the second excitation coil 30 and the third excitation coil 40 between the modules, so as to adapt to the light-emitting diode display panel structure that is independently driven by a plurality of light-emitting diode display modules. This allows the light-emitting diode display modules to fit tightly and seamlessly, and when replacement is required due to a lamp bead failure, only the corresponding light-emitting diode display module needs to be replaced. In addition, the above-mentioned scheme uses low-voltage differential signals for data transmission between boards, achieving a larger bandwidth with fewer wiring harnesses on the substrate, and solving the problem of high output transmission cost caused by large COB data load at a very low cost.

[0073] A display device comprises the above-mentioned light emitting diode display panel.

[0074] Specifically, the driving system of the light-emitting diode display panel is as shown in the above-mentioned embodiments and the accompanying drawings. The output end of the first driving device 10 includes a first differential signal output end and a second differential signal output end. The first driving device 10 uses two wires (i.e., differential signal wires) to transmit a signal and is driven by a current source. The light-emitting diode display panel of this embodiment is assembled using a plurality of independently driven light-emitting diode display modules, that is, each light-emitting diode display module includes a driving chip 94 and a lamp bead array 93 matching the load capacity of the driving chip 94. The display driving operation of the lamp bead array 93 in the corresponding light-emitting diode display module can be realized through the driving chip 94.

[0075] Among them, the first-level LED display module is the LED display module into which the differential signal output by the first driving device 10 first enters. Each LED display module is correspondingly provided with a second excitation coil 30 and a third excitation coil 40, wherein the second excitation coil 30 of the first-level LED display module is coupled with the first excitation coil 20, receives the signal output by the first driving device 10 for display driving of the lamp bead array 93, and then transmits it to the first receiving device 50 connected thereto for receiving, and finally sends it to the lamp bead array 93 through the first receiving device 50 to realize the display driving of the lamp bead. At the same time, the signal received by the second coupling coil is also synchronously transmitted to the third excitation coil 40 in the same-level LED display module, and finally transmits it to the next-level LED display module through the coupling between the third excitation coil 40 and the second excitation coil 30 of the next-level LED display module, so as to realize the cross-board transmission of the signal.

[0076] In the above-mentioned display device, the light-emitting diode display panel includes a plurality of light-emitting diode display modules that are driven independently of each other, and the signals between the light-emitting diode display modules are realized through the coupling of the second excitation coil 30 and the third excitation coil 40 between the modules, thereby adapting to the light-emitting diode display panel structure that is independently driven by a plurality of light-emitting diode display modules. This allows the light-emitting diode display modules to fit tightly and seamlessly, and when replacement is required due to a lamp bead failure, only the corresponding light-emitting diode display module needs to be replaced. In addition, in the above-mentioned scheme, data is transmitted between boards in the form of low-voltage differential signals, achieving a larger bandwidth with fewer wiring harnesses on the substrate, and solving the problem of high output transmission cost caused by large COB data load at a very low cost.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A driving system for a light emitting diode display panel, characterized in that: The light emitting diode display panel includes a plurality of independently driven light emitting diode display modules, and the driving system includes: A first driving device, wherein a power supply terminal of the first driving device is connected to a current source, and a ground terminal of the first driving device is grounded; a first excitation coil, wherein a first differential signal output terminal of the first driving device is connected to a first end of the first excitation coil, and a second differential signal output terminal of the first driving device is connected to a second end of the first excitation coil; A second excitation coil is provided in the light emitting diode display module, and the second excitation coil in the first-level light emitting diode display module is coupled with the first excitation coil, and the second excitation coil not in the first-level light emitting diode display module is coupled with the third excitation coil of the previous-level light emitting diode display module; A first receiving device is provided in the light-emitting diode display module, wherein a first input end of the first receiving device is connected to a first end of a second excitation coil in the same-level light-emitting diode display module, a second input end of the first receiving device is connected to a second end of the second excitation coil in the same-level light-emitting diode display module, and an output end of the first receiving device is connected to a lamp bead array of the same-level light-emitting diode display module; The third excitation coil is arranged in the light-emitting diode display module. The first end and the second end of the third excitation coil are respectively connected to the first end and the second end of the second excitation coil of the same-level light-emitting diode display module. The third excitation coil is coupled with the second excitation coil of the next-level light-emitting diode display module.

2. The drive system according to claim 1, characterized in that: The driving system also includes a second receiving device and a second driving device, the input end of the second driving device is connected to the lamp bead array of the same-level LED display module, the first output end of the second driving device is connected to the first end of the second excitation coil in the same-level LED display module, the second output end of the second driving device is connected to the second end of the second excitation coil in the same-level LED display module, the first input end of the second receiving device is connected to the first end of the first excitation coil, the second input end of the second receiving device is connected to the second end of the first excitation coil, and the output end of the second receiving device is connected to an external controller.

3. The drive system according to claim 1, characterized in that: The first driving device includes a first switching device, a second switching device, a third switching device and a fourth switching device, wherein the first end of the first switching device is connected to the first end of the third switching device and the common end is connected to a current source, the second end of the first switching device is connected to the first end of the second switching device and the common end is connected to the first end of the first excitation coil, the second end of the third switching device is connected to the first end of the fourth switching device and the common end is connected to the second end of the first excitation coil, the second end of the second switching device is connected to the second end of the fourth switching device and the common end is grounded, and the control ends of the first switching device, the second switching device, the third switching device and the fourth switching device are respectively connected to external controllers.

4. The drive system according to claim 3, characterized in that: The first receiving device includes a resistor and a receiver, the first input end of the receiver is connected to the first end of the resistor, and the common end is connected to the first end of the second excitation coil of the same-level light-emitting diode display module, the second input end of the receiver is connected to the second end of the resistor, and the common end is connected to the second end of the second excitation coil of the same-level light-emitting diode display module, and the output end of the receiver is connected to the lamp bead array of the same-level light-emitting diode display module.

5. The drive system according to claim 1, characterized in that: The first driving device includes a driver and a first micro control unit, the power supply end of the driver is connected to a current source, the ground end of the driver is grounded, the first output end of the driver is connected to the first micro control unit and the common end is connected to the first end of the first excitation coil, and the second output end of the driver is connected to the first micro control unit and the common end is connected to the second end of the first excitation coil.

6. The drive system according to claim 5, characterized in that: The first receiving device includes a second micro control unit, a resistor and a receiver, wherein the first input end of the receiver is connected to the first end of the resistor, and the common end is connected to the second micro control unit and the first end of the second excitation coil of the same-level light-emitting diode display module; the second input end of the receiver is connected to the second end of the resistor, and the common end is connected to the second micro control unit and the second end of the second excitation coil of the same-level light-emitting diode display module, and the output end of the receiver is connected to the lamp bead array of the same-level light-emitting diode display module.

7. The drive system according to claim 3, characterized in that: The first switch device, the second switch device, the third switch device and the fourth switch device are all transistors, field effect transistors or insulated gate bipolar transistors.

8. The drive system according to any one of claims 1 to 7, characterized in that: The number of the first driving devices is two or more.

9. A light emitting diode display panel, characterized in that: A drive system comprising any one of claims 1 to 8.

10. A display device, characterized in that: Comprising the light emitting diode display panel as claimed in claim 9.

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