CN115731846A

CN115731846A - Light emitting diode display panel, driving system thereof and display device

Info

Publication number: CN115731846A
Application number: CN202111025687.0A
Authority: CN
Inventors: 王朝; 朱卫强
Original assignee: Shenzhen Zhouming Technology Co Ltd
Current assignee: Shenzhen Zhouming Technology Co Ltd
Priority date: 2021-09-02
Filing date: 2021-09-02
Publication date: 2023-03-03
Also published as: WO2023029639A1

Abstract

The application relates to a light emitting diode display panel and a driving system and a display device thereof, wherein the light emitting diode display panel comprises a plurality of light emitting diode display modules which are mutually independent to drive, and signals between the light emitting diode display modules are realized through the coupling of a second excitation coil and a third excitation coil between the modules, so that the light emitting diode display panel structure which is matched with the plurality of light emitting diode display modules and is independently driven is realized. The LED display module can be closely attached and seamlessly spliced, and when the lamp bead is needed to be replaced due to failure of the lamp bead, the corresponding LED display module is only needed to be replaced. According to the scheme, data transmission is carried out between the boards in a low-voltage differential signal mode, larger bandwidth is achieved under fewer wiring harnesses on the substrate, and the problem of high output transmission cost caused by large COB data carrying capacity is solved with extremely low cost.

Description

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

Technical Field

The present disclosure relates to display technologies, and particularly to a light emitting diode display panel, a driving system thereof, and a display device.

Background

An LED (Light-Emitting Diode) display screen is a device that encapsulates an LED on a substrate and displays various information such as text, images, and video by using Light emitted from the LED. The LED display screen integrates the microelectronic technology, the computer technology and the information processing, and has the advantages of bright color, wide dynamic range, high brightness, long service life, stable and reliable work and the like. The LED display screen is widely applied to commercial media, cultural performance markets, stadiums, information dissemination, news distribution, security trading and the like, and can meet the requirements of different environments.

At present, there are two main technical forms for packaging LED display screens, one of which is SMD (Surface Mounted Devices) packaging, and the other is COB (chip on Board) packaging. COB packaging is a semiconductor packaging process in which a chip is attached to an interconnection substrate with a conductive or non-conductive adhesive and then wire-bonded to achieve electrical connection thereof. In short, the light emitting chip is directly mounted on a PCB (Printed Circuit Board), and a support and a solder fillet are not required. Compared with the SMD method, the COB packaging omits the processes of manufacturing LED chips into lamp beads, reflow soldering and the like. The light-emitting chip can be directly assembled on the PCB substrate without the limitation of the size of a packaging device, and can realize smaller dot pitch arrangement, thereby displaying high-definition content.

Compared with SMD packaging, COB packaging can put more dense and smaller lamp beads under the same substrate size, and the pixel density of COB packaging type LED display screens can be far higher than that of surface-mounted SMD packaging type LED display screens, which means that the data volume which can be carried in COB packaging technology can be tens of times of that of SMD packaging. Therefore, the bandwidth of the data transmission line applied to the COB packaging type LED display screen is wider, or the wire harness is more, and the cost of the data transmission and distribution scheme for the screen is higher.

Disclosure of Invention

Therefore, it is necessary to provide a light emitting diode display panel, a driving system thereof, and a display device, in order to solve the problem of high data transmission cost of the conventional COB package type LED display panel.

A driving system of an LED display panel, the LED display panel comprising a plurality of independently driven LED display modules, the driving system comprising: the power supply end of the first driving device is connected with the current source, and the grounding end of the first driving device is grounded; a first differential signal output end of the first driving device is connected with a first end of the first excitation coil, and a second differential signal output end of the first driving device is connected with a second end of the first excitation coil; the second excitation coil is arranged on the light-emitting diode display module, the second excitation coil positioned on the first-stage light-emitting diode display module is coupled with the first excitation coil, and the second excitation coil not positioned on the first-stage light-emitting diode display module is coupled with the third excitation coil of the previous-stage light-emitting diode display module; the first receiving device is arranged on the LED display module, a first input end of the first receiving device is connected with a first end of a second excitation coil in the same-level LED display module, a second input end of the first receiving device is connected with a second end of the second excitation coil in the same-level LED display module, and an output end of the first receiving device is connected with a lamp bead array of the same-level LED display module; and the first end and the second end of the third excitation coil are respectively connected with the first end and the second end of the second excitation coil of the same-stage light-emitting diode display module, and the third excitation coil is coupled with the second excitation coil of the next-stage light-emitting diode display module.

In one embodiment, the driving system further includes a second receiving device and a second driving device, an input end of the second driving device is connected to the bead array of the same-stage led display module, a first output end of the second driving device is connected to a first end of a second excitation coil in the same-stage led display module, a second output end of the second driving device is connected to a second end of a second excitation coil in the same-stage led display module, a first input end of the second receiving device is connected to a first end of the first excitation coil, a second input end of the second receiving device is connected to a second end of the first excitation coil, and an output end of the second receiving device is connected to an external controller.

In one embodiment, the first driving apparatus includes a first switching device, a second switching device, a third switching device and a fourth switching device, a first terminal of the first switching device is connected to a first terminal of the third switching device and a common terminal is connected to a current source, a second terminal of the first switching device is connected to a first terminal of the second switching device and a common terminal is connected to a first terminal of the first excitation coil, a second terminal of the third switching device is connected to a first terminal of the fourth switching device and a common terminal is connected to a second terminal of the first excitation coil, a second terminal of the second switching device is connected to a second terminal of the fourth switching device and a common terminal is grounded, and control terminals of the first switching device, the second switching device, the third switching device and the fourth switching device are respectively connected to an external controller.

In one embodiment, the first receiving device includes a resistor and a receiver, a first input end of the receiver is connected to a first end of the resistor, and a common end of the receiver is connected to a first end of a second excitation coil of the same-stage led display module, a second input end of the receiver is connected to a second end of the resistor, and the common end of the receiver is connected to a second end of a second excitation coil of the same-stage led display module, and an output end of the receiver is connected to a bead array of the same-stage led display module.

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

In one embodiment, the first receiving device comprises a second micro control unit, a resistor and a receiver, wherein a first input end of the receiver is connected with a first end of the resistor, and a common end of the receiver is connected with the second micro control unit and a first end of a second excitation coil of a same-level light-emitting diode display module; the second input end of the receiver is connected with the second end of the resistor, the public end of the receiver is connected with the second ends of the second excitation coils of the second micro control unit and the same-level light-emitting diode display module, and the output end of the receiver is connected with the lamp bead array of the same-level light-emitting diode display module.

In one embodiment, the first switching device, the second switching device, the third switching device, and the fourth switching device are all a transistor, a field effect transistor, or an insulated gate bipolar transistor.

In one embodiment, the number of the first driving devices is two or more.

A light emitting diode display panel comprises the driving system.

A display device comprises the light emitting diode display panel.

According to the light emitting diode display panel, the driving system and the display device, the light emitting diode display panel comprises the plurality of light emitting diode display modules which are driven independently, and 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 that the light emitting diode display panel is matched with the light emitting diode display panel structure which is driven independently by the plurality of light emitting diode display modules. The LED display module can be closely attached and seamlessly spliced, and when the lamp bead is needed to be replaced due to failure of the lamp bead, the corresponding LED display module is only needed to be replaced. According to the scheme, data transmission is carried out between the boards in a low-voltage differential signal mode, larger bandwidth is achieved under fewer wiring harnesses on the substrate, and the problem of high output transmission cost caused by large COB data carrying capacity is solved with extremely low cost.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a driving system of an LED display panel according to an embodiment;

FIG. 2 is a schematic diagram of a data transmission process of the driving system according to an embodiment;

FIG. 3 is an exploded view of an embodiment of a dual-layer LED display module;

FIG. 4 is a schematic diagram of a first surface structure of a single-layer LED display module according to an embodiment;

FIG. 5 is a schematic diagram of a second surface structure of a single-layer LED display module according to an embodiment;

FIG. 6 is a schematic view of a drive system according to another embodiment;

FIG. 7 is a schematic structural diagram of a drive system in yet another embodiment;

FIG. 8 is a schematic structural diagram of a driving system in a further embodiment;

fig. 9 is a schematic structural diagram of a driving system in yet another embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Referring to fig. 1, a driving system of an led display panel includes a plurality of independently driven led display modules, the driving system includes: a first driving device 10, wherein a power supply end of the first driving device 10 is connected with a current source, and a grounding end of the first driving device 10 is grounded; a first excitation coil 20, a first differential signal output terminal of the first driving device 10 is connected to a first end of the first excitation coil 20, and a second differential signal output terminal of the first driving device 10 is connected to a second end of the first excitation coil 20; the second excitation coil 30 is arranged on the led display module, the second excitation coil 30 in the first stage of the led display module is coupled with the first excitation coil 20, and the second excitation coil 30 not in the first stage of the led display module is coupled with the third excitation coil 40 in the previous stage of the led display module; the first receiving device 50 is arranged on the LED display module, a first input end of the first receiving device 50 is connected with a first end of a second excitation coil 30 in the same-stage LED display module, a second input end of the first receiving device 50 is connected with a second end of the second excitation coil 30 in the same-stage LED display module, and an output end of the first receiving device 50 is connected with a lamp bead array of the same-stage LED display module; and a third excitation coil 40 disposed on the led display module, wherein a first end and a second end of the third excitation coil 40 are respectively connected to a first end and a second end of the second excitation coil 30 of the same stage of the led display module, and the third excitation coil 40 is coupled to the second excitation coil 30 of the next stage of the led display module.

Specifically, the output terminal of the first driving device 10 includes a first differential signal output terminal and a second differential signal output terminal, and the first driving device 10 transmits one signal using two lines (i.e., differential signal lines) and drives using a current source. The light emitting diode display panel of the embodiment is assembled by adopting a plurality of independently driven light emitting diode display modules, namely, each light emitting diode display module comprises a driving chip and a lamp bead array matched with the driving chip in loading capacity, and the display driving operation of the lamp bead arrays in the corresponding light emitting diode display modules can be realized through the driving chip.

The first stage of led display module is an 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 stage led display module is coupled with the first excitation coil 20 to receive the signal output by the first driving device 10 and used for the display driving of the lamp bead array, and then the signal is transmitted to the first receiving device 50 connected with the first receiving device to be received, and finally the signal is transmitted to the lamp bead array through the first receiving device 50 to realize the display driving of the lamp bead. Meanwhile, the signal received by the second coupling coil is also synchronously transmitted to the third excitation coil 40 in the same-stage light emitting diode display module, and finally transmitted to the next-stage light emitting diode display module through the coupling between the third excitation coil 40 and the second excitation coil 30 of the next-stage light emitting diode display module, so that the cross-plate transmission of the signal is realized.

It should be pointed out that each emitting diode display module assembly all includes driver chip and with this driver chip area carrying capacity assorted lamp pearl array, specifically can be a driver chip area carrying capacity and a lamp pearl array phase-match, in the emitting diode display module assembly this moment, can set up the same driver chip of quantity and lamp pearl array simultaneously, each driver chip corresponds a lamp pearl array of drive to realize that the lamp pearl quantity of the whole emitting diode display module assembly bead array matches with driver chip's area carrying capacity.

In another embodiment, the loading capacity of the m driving chips can be matched with the n bead arrays, wherein m and n are positive integers greater than 1, and m and n are not equal. Also in this embodiment, in the same independently driven emitting diode display module assembly, can set up m driver chip and n lamp pearl array, utilize m driver chip to drive n lamp pearl array simultaneously to make the lamp pearl quantity of pearl array and driver chip's the ability phase-match of carrying in whole emitting diode display module assembly.

In a more detailed embodiment, please refer to fig. 2, which illustrates an example of the first-level led display module performing signal transmission. The data related to display driving is generated from the data output preceding stage, the TTL level signal is converted into an LVDS (low voltage differential signaling) signal in the first driving device 10, the LVDS signal is transmitted from two differential signal output ends of the first driving device 10, the LVDS signal is induced by the first excitation coil 20 and is transmitted to the first led display module, the first receiving device 50 of the first led display module judges whether to receive the data, if the data is received, the circuit is switched on, the high frequency signal is output through an output end of the first receiving device 50, the LVDS signal is converted into the TTL signal, and the TTL signal is transmitted to the lamp bead array of the display module, so that the transmission of the whole data is completed. If the MCU determines not to receive data, the receiving circuit is not turned on, and the high frequency data is transmitted to the next stage of led display module by the second exciting coil 30 and the third exciting coil 40 coupled between the two display modules in LVDS mode.

It should be noted that the embodiment shown in fig. 2 only uses the conducting bit string of the first-level led display module, and in practical applications, once the data is conducted at the last receiving end, the data will be naturally transmitted to the next receiving end. The second excitation coil 30 and the third excitation row right are cascaded step by step through the splicing of the display modules, and a high-speed LVDS data transmission channel is created. In this channel, the data from the first driving device 10 is rapidly transmitted to the second exciting coil 30 and the first receiving device 50 thereof on each display module, and the first receiving device 50 only needs to analyze and determine whether to receive the data.

Specifically, assuming that the data is divided according to the display module 1, the display module 2, and the display module 3, when the data of the display module 1 is transmitted, the second excitation coil 30 on the display module 2 and the display module 3 will also receive the same data as the display module 1, but the first receiving device 50 can control whether to further transmit the data to the corresponding lamp bead array. Similarly, when transmitting the data of the display module 2 or the display module 3, the data will also pass through the display module 1, and at this time, the display module 1 may also select to receive or not receive the data.

The excitation coil carries out signal transmission in a high-frequency wireless mode in a short distance, and is designed based on the module splicing characteristics of the LED display screen. The display module assembly can have accurate location in concatenation position department, and two display module assemblies closely laminate, and after the module concatenation was accomplished, the corresponding location of coil was accurate, and the distance is inseparable, can be with high efficiency transmission data. In the embodiment, the low-voltage differential signals are adopted for data transmission, and compared with the existing LED module data transmission scheme, the data carrying capacity is higher, and the anti-interference capacity is strong.

In the data distribution scheme of the embodiment, the LVDS data signals are sensed by the exciting coil between the plates to transmit data to the next-stage display module, and the adaptive design is made on the basis of the splicing characteristics of the LED display modules. Specifically, the LED display module is tightly attached to the position of a splicing seam, and the requirement on the flatness of splicing is extremely high. This means that the distance between the two plates is extremely small, and the positioning precision is high, which creates good conditions for the excitation coil coupling. Further say, if do not adopt excitation coil induced current to carry out data transmission between the board, just need directly to connect several signal lines between the board, when the dismouting module, these cross board signal lines can involve the display module assembly, influence the dismouting, also influence the quality of module installation and data transmission's quality simultaneously.

By utilizing the characteristic, the cross-board data communication of the COB-packaged LED display screen in the embodiment is mainly realized by the induction transmission of the display data by the high-frequency excitation coil. Data is wirelessly transmitted between boards in LVDS mode at high speed. For the whole display screen, the whole display screen is divided into a plurality of driving ends (i.e. a plurality of first driving devices 10 are provided), the driving ends can carry one or more receiving ends (i.e. at least one first receiving device 50) and the receiving ends are installed on the display modules, which means that one driving end can carry one or more display modules.

It should be noted that the specific structure of the independently driven led display module is not exclusive, and in one embodiment, the independently driven led display module may be a double-layer structure type led display module, and in another embodiment, the independently driven led display module may also be a single-layer structure type led display module.

For example, referring to fig. 3, the led display module includes a lamp bead substrate 91, a driving substrate 92, a lamp bead array 93, and a driving chip 94, wherein the lamp bead array 93 is disposed on the lamp bead substrate 91, the driving chip 94 is disposed on a first surface of the driving substrate 92, a second surface of the driving substrate 92 opposite to the first surface is provided with a solder joint, row driving pins and column driving pins of the driving chip 94 are respectively connected to the lamp bead array 93, and the number of lamp beads of the lamp bead array 93 matches with the carrying capacity of the driving chip 94.

The driving chip 94 and the driving substrate 92 form a driving layer, the bead array 93 and the bead substrate 91 form a display bead layer, and the led display module adopts a double-layer structure design. The light emitting diode display module is obtained by arranging the light bead array 93 and the driving chip 94 on different substrates, namely a light bead substrate 91 and a driving substrate 92, and then connecting the driving chip 94 and the light bead array 93 in a cross-layer manner. The second surface of the driving substrate 92 is provided with solder pads, so that the entire led display module can be directly soldered to the substrate of the led display panel through the solder pads, thereby forming an led display panel. The driving substrate 92 is divided into a front surface and a back surface, and the front surface (i.e., the first surface) is mainly a constant current output driving chip 94, and in another embodiment, may further include a constant current adjusting resistor. The driver chip 94 is capable of outputting all of the display signals required by the lamp beads. The opposite (i.e., second surface) is a plurality of solder connection nodes, which in a more detailed embodiment may be BGA ball pads. Therefore, the LED display module can be directly packaged on the substrate by heating and welding like the current chip packaging.

Further, in an embodiment, the led display module may further include a connection layer 95, the connection layer 95 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. Further, in an embodiment, the led display module further includes a surface sealing layer 96, and the surface sealing layer 96 is disposed on the bead array 93 in a covering manner.

Or in another embodiment, please refer to fig. 4-5 in combination, the led display module includes an integrated substrate 97, a bead array 93, and a driving chip 94, the bead array 93 is disposed on a first surface of the integrated substrate 97, the driving chip 94 is disposed on a second surface of the integrated substrate 97, the first surface and the second surface are disposed opposite to each other, the integrated substrate 97 is provided with a wire passing hole, row driving pins and column driving pins of the driving chip 94 are respectively connected to the bead array 93 through the wire passing hole, and the number of beads of the bead array 93 matches with the carrying 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 led display module uses only a single PCB (i.e., a substrate), the front surface (i.e., the first surface) as a package layer of the display beads, and the back surface (i.e., the second surface) as a package layer of the driver chip 94, and also as a mounting position of the connection pins. Compared with the double-layer structure, the hierarchical relation is reduced, and the lamp bead array 93 is directly connected with the driving chip 94 from the wire passing hole to the back of the PCB.

Referring to fig. 6, in an embodiment, the driving system further includes a second receiving device 70 and a second driving device 60, an input end of the second driving device 60 is connected to the bead array 93 of the same-level led display module, a first output end of the second driving device 60 is connected to a first end of a second excitation coil 30 in the same-level led display module, a second output end of the second driving device 60 is connected to a second end of the second excitation coil 30 in the same-level led display module, a first input end of the second receiving device 70 is connected to a first end of a first excitation coil 20, a second input end of the second receiving device 70 is connected to a second end of the first excitation coil 20, and an output end of the second receiving device 70 is connected to an external controller.

Specifically, in the LED display screen, the excitation coil has two corresponding relations, 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 stage of LED display module, where 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. Second, in the two tiled display modules, that is, the third excitation coil 40 and the second excitation coil 30 in the next led display module, the LVDS signals introduced into the modules are continuously transmitted along the excitation coils step by step on the modules.

However, on this transmission path, data is transmitted unidirectionally without feedback. In some application scenarios, the display module based on LVDS communication needs to implement bidirectional data communication, and in combination with the structural features of the led display module, the data rate of the return data, including data content, can be smaller or slower than that of the direct data transmission.

In this embodiment, a driving system of a half-duplex structure type is adopted, a second driving device 60 is simultaneously provided at the led display module, a second receiving device 70 is simultaneously connected to the first exciting coil 20, the first driving device 10 and the first receiving device 50 perform data transmission, and when the display driving control is performed on the led display panel, the communication between the second driving device and the second receiving device 70 is turned off. When the feedback data is transmitted back between the second driving device 60 and the second receiving device 70, 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 driving system of the embodiment is utilized to realize the data bidirectional transmission between the boards.

It should be noted that the specific structure of the first driving apparatus 10 is not exclusive, and in one embodiment, referring to fig. 7 in combination, the first driving apparatus 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 terminal of the first switching device Q1 is connected to a first terminal of the third switching device Q3 and a common terminal is connected to a current source, a second terminal of the first switching device Q1 is connected to a first terminal of the second switching device Q2 and a common terminal is connected to a first terminal of the first field coil 20, a second terminal of the third switching device Q3 is connected to a first terminal of the fourth switching device Q4 and a common terminal is connected to a second terminal of the first field coil 20, a second terminal of the second switching device Q2 is connected to a second terminal of the fourth switching device Q4 and a common terminal is grounded, and control terminals 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 an external controller.

Specifically, when the second switching device Q2 and the third switching device Q3 are turned on and the first switching device Q1 and the fourth switching device Q4 are turned off by the external controller, the current of the current source flows to the first exciting coil 20 through the second terminal of the third switching device Q3, flows back to the second switching device Q2 through the first exciting coil 20, and is grounded through the second switching device Q2, forming a closed loop. When a current flows through the first exciting coil 20, an induced current is generated on the second exciting coil 30 of the first stage led display module, and the direction of the induced current is opposite to the direction of the current on the first exciting 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 second terminal voltage of the first receiving device 50 is higher than the first terminal voltage, and the output of the first receiving device 50 is at a high level.

When the second switching device Q2 and the third switching device Q3 are turned off and the first switching device Q1 and the fourth switching device Q4 are turned on by the external controller, the current of the current source flows to the first exciting coil 20 through the second terminal of the first switching device Q1, flows back to the fourth switching device Q4 through the first exciting coil 20, and is grounded through the fourth switching device Q4, thereby forming a closed loop. When a current flows through the first exciting coil 20, an induced current is generated on the second exciting coil 30 of the first stage led display module, and the direction of the induced current is opposite to the direction of the current on the first exciting 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 first terminal voltage of the first receiving device 50 is higher than the second terminal voltage, and the output of the first receiving device 50 is at a low level. Therefore, required data transmission function is accomplished through low pressure differential signal, and each excitation coil can realize split or laminating through specific winding mode, and this characteristic is used on the concatenation module, just can make the module not receive the pencil restraint to the wireless form realizes striding board data transmission.

Accordingly, in an embodiment, referring to fig. 7 in combination, the first receiving device 50 includes a resistor 51 and a receiver 52, a first input terminal of the receiver 52 is connected to a first terminal of the resistor 51, a common terminal of the receiver is connected to a first terminal of the second excitation coil 30 of the same stage of led display module, a second input terminal of the receiver 52 is connected to a second terminal of the resistor 51, the common terminal of the receiver is connected to a second terminal of the second excitation coil 30 of the same stage of led display module, and an output terminal of the receiver 52 is connected to the bead array 93 of the same stage of led display module.

Specifically, in the embodiment, the first receiving device 50 includes a resistor 51 and a receiver 52, and when a current flows through the first exciting coil 20, an induced current is generated on the second exciting coil 30 of the first-stage led display module, and when the induced current acts on the resistor 51 of the first receiving device 50, a certain voltage drop is generated. Depending on the flow direction of the induced current, the first terminal voltage of the receiver 52 is greater than the second terminal voltage, and the second terminal voltage is greater than the first terminal voltage, and then a high level and a low level are output.

It is understood that the specific structure of the first driving device 10 and the first receiving device 50 can be applied to the driving system of the led display panel with unidirectional data transmission in the above embodiment, or the driving system of the half-duplex led display panel. Further, in an 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 are not repeated herein.

Further, referring to fig. 8, in an embodiment, the first driving apparatus 10 includes a driver 11 and a first mcu 12, a power source terminal of the driver 11 is connected to a current source, a ground terminal of the driver 11 is grounded, a first output terminal of the driver 11 is connected to the first mcu 12 and a common terminal of the driver 11 is connected to a first terminal of the first excitation coil 20, a second output terminal of the driver 11 is connected to the first mcu 12 and a common terminal of the driver is connected to a second terminal of the first excitation coil 20.

Specifically, the specific structure of the driver 11 is not exclusive, and 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, a first terminal of the first switching device is connected to a first terminal of the third switching device, and a common terminal is connected to the current source, a second terminal of the first switching device is connected to a first terminal of the second switching device and the common terminal is connected to the first micro control unit 12 and the first terminal of the first exciting coil 20, a second terminal of the third switching device is connected to a first terminal of the fourth switching device, and the common terminal is connected to the first micro control unit 12 and the second terminal of the first exciting coil 20, a second terminal of the second switching device is connected to a second terminal of the fourth switching device and the common terminal is grounded, and control terminals of the first switching device, the second switching device, the third switching device and the fourth switching device are respectively connected to the external controller.

In the solution of this embodiment, a driver 11 is formed by combining bridge structures of a first switching device, a second switching device, a third switching device and a fourth switching device, and in the solution of this embodiment, the first driving apparatus 10 further includes a first micro control unit 12 besides the driver 11, where the first micro control unit 12 is disposed between the driver 11 and the first excitation coil 20, and is used for monitoring a data signal returned by the led display module and recording the data signal.

Further, referring to fig. 8, in an embodiment, the first receiving device 50 includes a second micro control unit 53, a resistor 51 and a receiver 52, a first input terminal of the receiver 52 is connected to a first terminal of the resistor 51, and a common terminal is connected to the second micro control unit 53 and a first terminal of the second excitation coil 30 of the same stage of the led display module; the second input end of the receiver 52 is connected to the second end of the resistor 51, 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 led display module, and the output end of the receiver 52 is connected to the lamp bead array 93 of the same-level led display module.

Specifically, in the scheme, a second micro control unit 53 is connected in parallel at the receiving end of each display module, which can be regarded as a load different from the resistor 51, and the voltage drop of the load is much smaller than that of the resistor 51, so that when the second micro control unit 53 is turned on, current can preferentially pass through the second micro control unit 53, and different voltage drops are generated. This voltage drop is much smaller than the voltage drop across resistor 51, so that for the first field coil, a significantly different current change occurs. Specifically, as the load decreases, the current decreases accordingly. The second mcu 53 can be understood as a circuit without a voltage drop, and the resistor 51 has a certain voltage drop across it. When the second micro control unit 53 is not conducting, the voltage drop across the resistor 51 becomes high. By switching the voltage drop, the circuit influence on the first exciting coil 20 is realized, and simple data content is fed back to the first coil.

The solution of this embodiment provides a bidirectional data transmission scheme different from the half-duplex structure, that is, a backhaul scheme during discharging. The display related data is transmitted from the first driving device 10, and is transmitted into the display module through the first exciting coil and the second exciting coil 30, the data can be transmitted on the whole channel instantly, and in combination with fig. 9, each module can receive the corresponding data to the display lamp bead array 93 only by combining the needs of the module, and then converts the data into the TTL format, thereby realizing the display driving. When data return is required, the second mcu 53 and the first mcu 12 need to be turned on for transmission. It should be noted that the second mcu 53 of any module of the connected modules can directly affect the first driving device 10 when it is turned on, so that the data can be transmitted back to the first driving device 10 from any module, instead of being transmitted back in stages. In one embodiment, the feedback signals of different modules can be distinguished by encoding in the header of the feedback data.

Through the scheme, at least the following three applications can be realized:

and (3) data correction: in the data transmission process, if it is determined whether the data reception on the single display module is complete without loss, the data needs to be corrected. The correction process is that a section of specific check bit is input at the end of each data transmission, and the control circuit on the module checks whether the received data is complete according to the check bit. If the data reception is correct and complete, the first driving device 10 is returned, and the current module has already received the data and is completed, and the display data required by the next module is now transmitted. If the data reception is incomplete, the first driving device 10 needs to be fed back that the data reception of the current module is incomplete and needs to be retransmitted. At this time, there is a need for returning data, which tells the first driving device 10 which led display module is currently receiving data, and how the integrity of the receiving is. Through a specific communication protocol, a data return method such as a semi-I type, a discharge type and the like can be utilized to return a specific code, so that the first driver can know the information of the current receiving module, and the function of self-correction of data transmission is completed.

Module automatic identification (automatic screen allocation): the light emitting diode display panel in this application is formed by jointly splicing a plurality of light emitting diode display modules, a plurality of first driving devices 10 are needed on a screen, the number of the display modules which can be carried by each first driving device 10 is limited, the number of the display modules formed on the whole display panel is uncertain, and under most conditions, the modules carried by different first driving devices 10 have irregular data transmission paths. Due to the random arrangement position of the modules, when data transmission is carried out, if the data are transmitted from the first-level display module to the last-level display module in sequence, the displayed pictures on the screen are disordered and are like a disordered jigsaw puzzle. To solve this problem, the conventional method needs manual debugging, that is, the data channel connection mode of each display panel is known, and the disordered pictures are arranged one by one, so that a complete display panel with correct sequence can be formed when data is directly transmitted. The debugging process is to clear the installation position relation of each module including the connection relation of channels and rearrange the sequence of sending data.

However, with the above-described configuration, if bidirectional data communication is enabled between the boards, the current positional relationship can be determined from each other, and the positional relationship is transmitted back to the first driving device 10, so that the data transmission data can be automatically adjusted, and the automatic identification of the module can be realized. When the screen is started and powered on, the current connection relation and the data sending sequence can be automatically confirmed, and the display pictures which are sorted out of sequence can be automatically arranged into complete display pictures.

Impedance self-adaptive identification: the scheme of this embodiment adopts low voltage differential signal transmission data, has the step of excitation coil conversion again between the board simultaneously, and data must produce the current loss owing to line loss and electromagnetic induction in the transmission course for the electric current is finally stayed on every module, all can have slight difference. This difference can be obtained by detecting two data lines on the display module (i.e. the communication line between the second excitation coil 30 and the third excitation coil 40 in the same led display module).

It is to be understood that the type of switching device in the first driving apparatus 10 is not exclusive, and in one embodiment, the first switching device Q1, the second switching device Q2, the third switching device Q3, and the fourth switching device Q4 are all transistors, field effect transistors, or insulated gate bipolar transistors. In other embodiments, the switching device may be implemented by using other types of switching devices as long as a corresponding bridge arm switching circuit can be constructed to output a low-voltage differential signal for data transmission.

In one embodiment, the number of the first driving devices 10 is two or more.

Specifically, in an actual application scenario, hundreds of or thousands or even more led display modules are often required to be spliced in the led display panel, and the driving capability of one first driving device 10 is limited, so that the driving operation of all the led display modules cannot be realized by one first driving device 10. Therefore, in this embodiment, two or more first driving devices 10 are provided, and each first driving device 10 can provide display-related data for a plurality of led display modules, thereby completing the driving of the entire led display panel.

In the driving system of the led display panel, the led display panel includes a plurality of led display modules that are independently driven, and signals between the led display modules are coupled by 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 independently driven by the plurality of led display modules. The LED display module can be closely attached and seamlessly spliced, and when the lamp bead is needed to be replaced due to failure of the lamp bead, the corresponding LED display module is only needed to be replaced. According to the scheme, data transmission is carried out between the boards in a low-voltage differential signal mode, larger bandwidth is achieved under fewer wiring harnesses on the substrate, and the problem that COB data are high in output transmission cost due to large loading capacity is solved with extremely low cost.

A light emitting diode display panel comprises the driving system.

Specifically, as shown in the above embodiments and the accompanying drawings, the output terminal of the first driving device 10 includes a first differential signal output terminal and a second differential signal output terminal, and the first driving device 10 uses two lines (i.e., differential signal lines) to transmit one signal and uses a current source for driving. The led display panel of this embodiment is assembled by using a plurality of independently driven led display modules, that is, each led display module includes a driving chip 94 and a lamp bead array 93 having a loading capacity matched with that of the driving chip 94, and the display driving operation of the lamp bead array 93 in the corresponding led display module can be realized by the driving chip 94.

The first stage of led display module is an 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 stage led display module is coupled with the first excitation coil 20, receives a signal output by the first driving device 10 and used for displaying and driving the lamp bead array 93, and then transmits the signal to the first receiving device 50 connected with the first receiving device to receive the signal, and finally transmits the signal to the lamp bead array 93 through the first receiving device 50 to realize the displaying and driving of the lamp beads. Meanwhile, the signal received by the second coupling coil is also synchronously transmitted to the third excitation coil 40 in the same-stage light emitting diode display module, and finally transmitted to the next-stage light emitting diode display module through the coupling between the third excitation coil 40 and the second excitation coil 30 of the next-stage light emitting diode display module, so that the cross-plate transmission of the signal is realized.

In the above led display panel, the led display panel includes a plurality of led display modules that are driven independently from each other, and signals between the led display modules are coupled by 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 driven independently by the plurality of led display modules. The LED display modules can be closely attached and seamlessly spliced, and when the lamp beads are needed to be replaced due to failure, the corresponding LED display modules are only needed to be replaced. According to the scheme, data transmission is carried out between the boards in a low-voltage differential signal mode, larger bandwidth is achieved under fewer wiring harnesses on the substrate, and the problem that COB data are high in output transmission cost due to large loading capacity is solved with extremely low cost.

A display device comprises the light emitting diode display panel.

Specifically, as shown in the above embodiments and the accompanying drawings, the output terminal of the first driving device 10 includes a first differential signal output terminal and a second differential signal output terminal, and the first driving device 10 uses two lines (i.e., differential signal lines) to transmit one signal and uses a current source for driving. The light emitting diode display panel of this embodiment adopts a plurality of independent drive's light emitting diode display module assembly to assemble, also every light emitting diode display module assembly all includes driver chip 94 and with this driver chip 94 lamp pearl array 93 of carrying capacity assorted, through driver chip 94, can realize the display drive operation of lamp pearl array 93 among the corresponding light emitting diode display module assembly.

The first stage led display module is a 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 stage led display module is coupled with the first excitation coil 20, receives a signal output by the first driving device 10 and used for displaying and driving the lamp bead array 93, and then transmits the signal to the first receiving device 50 connected with the first receiving device to receive the signal, and finally transmits the signal to the lamp bead array 93 through the first receiving device 50 to realize the displaying and driving of the lamp beads. Meanwhile, the signal received by the second coupling coil is also synchronously transmitted to the third excitation coil 40 in the same-stage light emitting diode display module, and finally transmitted to the next-stage light emitting diode display module through the coupling between the third excitation coil 40 and the second excitation coil 30 of the next-stage light emitting diode display module, so that the cross-plate transmission of the signal is realized.

In the display device, the led display panel includes a plurality of led display modules driven independently, and signals between the led display modules are coupled by 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 independently driven by the plurality of led display modules. The LED display modules can be closely attached and seamlessly spliced, and when the lamp beads are needed to be replaced due to failure, the corresponding LED display modules are only needed to be replaced. According to the scheme, data transmission is carried out between the boards in a low-voltage differential signal mode, larger bandwidth is achieved under fewer wiring harnesses on the substrate, and the problem that COB data are high in output transmission cost due to large loading capacity is solved with extremely low cost.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A driving system of an LED display panel, wherein the LED display panel comprises a plurality of independently driven LED display modules, the driving system comprises:

the power supply end of the first driving device is connected with the current source, and the grounding end of the first driving device is grounded;

a first differential signal output end of the first driving device is connected with a first end of the first excitation coil, and a second differential signal output end of the first driving device is connected with a second end of the first excitation coil;

the second excitation coil is arranged on the light-emitting diode display module, the second excitation coil positioned on the first-stage light-emitting diode display module is coupled with the first excitation coil, and the second excitation coil not positioned on the first-stage light-emitting diode display module is coupled with the third excitation coil of the previous-stage light-emitting diode display module;

the first receiving device is arranged on the LED display module, a first input end of the first receiving device is connected with a first end of a second excitation coil in the same-stage LED display module, a second input end of the first receiving device is connected with a second end of the second excitation coil in the same-stage LED display module, and an output end of the first receiving device is connected with a lamp bead array of the same-stage LED display module;

and the first end and the second end of the third excitation coil are respectively connected with the first end and the second end of the second excitation coil of the same-stage light-emitting diode display module, and the third excitation coil is coupled with the second excitation coil of the next-stage light-emitting diode display module.

2. The driving system according to claim 1, further comprising a second receiving device and a second driving device, wherein an input terminal of the second driving device is connected to the bead array of the same stage of led display module, a first output terminal of the second driving device is connected to a first terminal of a second excitation coil in the same stage of led display module, a second output terminal of the second driving device is connected to a second terminal of the second excitation coil in the same stage of led display module, a first input terminal of the second receiving device is connected to a first terminal of the first excitation coil, a second input terminal of the second receiving device is connected to a second terminal of the first excitation coil, and an output terminal of the second receiving device is connected to an external controller.

3. The driving system according to claim 1, wherein the first driving apparatus includes a first switching device, a second switching device, a third switching device, and a fourth switching device, a first terminal of the first switching device is connected to a first terminal of the third switching device and a common terminal is connected to a current source, a second terminal of the first switching device is connected to a first terminal of the second switching device and a common terminal is connected to a first terminal of the first field coil, a second terminal of the third switching device is connected to a first terminal of the fourth switching device and a common terminal is connected to a second terminal of the first field coil, a second terminal of the second switching device is connected to a second terminal of the fourth switching device and a common terminal is grounded, and control terminals of the first switching device, the second switching device, the third switching device, and the fourth switching device are respectively connected to an external controller.

4. The driving system according to claim 3, wherein the first receiving device comprises a resistor and a receiver, a first input terminal of the receiver is connected to a first terminal of the resistor, and a common terminal of the receiver is connected to a first terminal of a second excitation coil of the same-stage LED display module, a second input terminal of the receiver is connected to a second terminal of the resistor, and the common terminal of the receiver is connected to a second terminal of the second excitation coil of the same-stage LED display module, and an output terminal of the receiver is connected to the bead array of the same-stage LED display module.

5. The driving system according to claim 1, wherein the first driving device comprises a driver and a first micro-control unit, a power supply terminal of the driver is connected with a current source, a ground terminal of the driver is grounded, a first output terminal of the driver is connected with the first micro-control unit and a common terminal is connected with a first terminal of the first excitation coil, and a second output terminal of the driver is connected with the first micro-control unit and a common terminal is connected with a second terminal of the first excitation coil.

6. The driving system according to claim 5, wherein the first receiving device comprises a second micro-control unit, a resistor and a receiver, a first input terminal of the receiver is connected to a first terminal of the resistor, and a common terminal is connected to the second micro-control unit and a first terminal of a second excitation coil of the same stage of light emitting diode display module; the second input end of the receiver is connected with the second end of the resistor, the public end of the receiver is connected with the second ends of the second excitation coils of the second micro control unit and the same-level light-emitting diode display module, and the output end of the receiver is connected with the lamp bead array of the same-level light-emitting diode display module.

7. The drive system of claim 3, wherein the first, second, third, and fourth switching devices are each a transistor, a field effect transistor, or an insulated gate bipolar transistor.

8. The drive system according to any one of claims 1 to 7, wherein the number of the first drive means is two or more.

9. A light emitting diode display panel comprising the driving system as claimed in any one of claims 1 to 8.

10. A display device comprising the light emitting diode display panel according to claim 9.