Sending card of LED display screen and control system of LED display screen

Abstract

The invention relates to a sending card of an LED display screen and a control system of the LED display screen, and relates to the technical field of LED display, the sending card comprises a main control module, and a first communication module and a crystal oscillator which are connected with the main control module; the first communication module of the sending card is connected with a cascaded sending card at the upper level through an Ethernet transmission link; the crystal oscillator is used for providing a first clock signal for the main control module; the communication module is used for recovering a third clock signal from Ethernet data received by a cascaded upper-level sending card and sending the recovered third clock signal to the main control module; and the main control module is used for taming the first clock signal based on the third clock signal and driving LED signal display based on the tamed first clock signal. According to the embodiment of the invention, the display smoothness of the LED display screen can be improved.

Description

Technical Field

[0001] The present application relates to the field of LED display technology, and in particular to a sending card for an LED display screen and a control system for the LED display screen. Background Art

[0002] With the development of LED display technology, the application of LED display is becoming more and more extensive. The normal display of each LED display is inseparable from the control of its corresponding control system. The control system is responsible for the drive display and signal access of the entire LED display. The control system includes a sending card and a receiving card. Among them, the sending card (also called a sending box) is responsible for signal access, and the receiving card is responsible for the driving of the LED light board. The load area of ​​each sending card is limited. When the resolution of the LED display exceeds the load area of ​​a single sending card, multiple sending card devices need to be cascaded to achieve the load of a large-resolution LED display. When multiple sending cards are cascaded, it is necessary to ensure that the sending cards can display synchronously, that is, they need to display the same frame of the picture at the same time to avoid the problem of screen tearing when the entire LED display is displayed.

[0003] The current method of achieving display synchronization between sending cards is prone to poor contact when the synchronization signal link ages, resulting in abnormal display on the display card. Summary of the invention

[0004] Based on this, it is necessary to provide a sending card for an LED display screen and a control system for an LED display screen that are helpful in improving the display smoothness of the LED display screen in order to solve the above technical problems.

[0005] In a first aspect, the present application provides a sending card for an LED display screen, wherein the sending card comprises: a main control module, a first communication module connected to the main control module, and a crystal oscillator; the first communication module of the sending card is connected to a cascaded upper-level sending card through an Ethernet transmission link;

[0006] The crystal oscillator is used to provide a first clock signal to the main control module;

[0007] The communication module is used to recover the third clock signal from the Ethernet data received by the upper-level sending card of the cascade, and send the recovered third clock signal to the main control module;

[0008] The main control module is used to tame the first clock signal based on the third clock signal, and drive the LED signal display based on the tamed first clock signal.

[0009] Based on the sending card of the present embodiment, after receiving the third clock signal sent by the cascaded upper-level sending card, the first clock signal of the local sending card is tamed based on the third clock signal. Since the first clock signal generated locally by the sending card is tamed by the third clock signal of the cascaded upper-level sending card, the clock signal generated locally by the sending card can be synchronized with the clock signal of the upper-level sending card, and the LED signal display is driven based on the tamed first clock signal. Therefore, even if the sending card is disconnected from the upper-level sending card due to some abnormality, the synchronization between the sending card and the upper-level sending card will not disappear instantly. After the link between the sending card and the upper-level sending card is restored, the synchronization will also be restored based on the received clock signal of the upper-level sending card. Therefore, in the process of the link between the sending card and the upper-level sending card being terminated due to an abnormality and being restored, the display synchronization will not be affected, so that the display smoothness of the LED display screen can be improved.

[0010] In some embodiments, the first communication module includes a synchronous Ethernet module.

[0011] Based on this embodiment, the sending card is connected to the upper level sending card via synchronous Ethernet, and a clock signal can be received from the upper level sending card via synchronous Ethernet. The method of transmitting the clock signal is simple and convenient.

[0012] In some embodiments, the first communication module is further used to parse out control instructions from Ethernet data received from the upper-level sending card of the cascade.

[0013] Based on this embodiment, the transmission and reception of clock signals and control instructions can be realized simultaneously through the first communication module, and there is no need to separately set up the transmission line of the control instruction and the transmission line of the clock signal, which saves line resources, simplifies the wiring cost between the sending cards, and reduces the wiring complexity. Taking the first communication module as a synchronous Ethernet module as an example, the synchronization of the clock signal can be realized through the synchronous Ethernet, and the transmission of the control command can be realized through the synchronous Ethernet, that is, the transmission of the clock signal and the control command can be realized simultaneously through a synchronous Ethernet connection line, which simplifies the wiring cost between the sending cards and reduces the wiring complexity.

[0014] In some embodiments, the main control module is used to generate a field synchronization signal based on the third clock signal, and use the first clock signal and the field synchronization signal to perform phase detection processing to obtain phase error data, and tame the first clock signal based on the phase error data.

[0015] Based on this embodiment, the main control module generates a field synchronization signal based on the third clock signal received from the previous-level sending card, uses the first clock signal and the field synchronization signal to perform phase detection processing to obtain phase error data, and then tames the first clock signal based on the phase error data, so that the first clock signal can be tamed based on the difference between the first clock signal of the sending card and the third clock signal of the previous-level sending card.

[0016] In some embodiments, the main control module is used to adjust the reference voltage of the crystal oscillator based on the phase error data so that the first clock signal output by the crystal oscillator is phase-locked with the third clock signal to tame the first clock signal.

[0017] Based on this embodiment, after obtaining the phase error data, the main control adjusts the reference voltage of the crystal oscillator according to the phase error data. By adjusting the reference voltage of the crystal oscillator, the first clock signal output by the crystal oscillator is phase-locked with the third clock signal of the previous level card delivery, thereby achieving the taming of the first clock signal.

[0018] In some embodiments, the sending card further includes a digital-to-analog converter connected to the main control module and the crystal oscillator;

[0019] The main control module adjusts the digital-to-analog converter based on the phase error data to adjust the reference voltage of the crystal oscillator.

[0020] Based on this embodiment, the sending card is provided with a digital-to-analog converter connected between the main control module and the crystal oscillator, and the digital-to-analog converter is adjusted based on the obtained phase error data to adjust the reference voltage of the crystal oscillator, thereby making the first clock signal output by the crystal oscillator phase-locked with the third clock signal of the previous-level sending card, thereby achieving the taming of the first clock signal, thereby enabling the precise adjustment of the first clock signal of the sending card.

[0021] In some embodiments, the sending card further comprises: a second communication module connected to the main control module; the second communication module of the sending card is connected to the next level sending card of the cascade via an Ethernet transmission link;

[0022] The main control module is further configured to send a second clock signal to the second communication module based on the first clock signal;

[0023] The second communication module is used to send the second clock signal to the next-level sending card in the cascade through Ethernet data. The second clock signal is used by the next-level sending card in the cascade to tame the local clock signal of the next-level sending card, and drive the LED signal display based on the tamed local clock signal.

[0024] Based on this embodiment, after the main control module of the sending card sends the second clock signal to the second communication module based on the received first clock signal, the second communication module sends the second clock signal to the next-level sending card in the cascade, so that the local clock signal of the next-level sending card in the cascade can be tamed by the second clock signal, so that the next-level sending card can drive the LED signal display based on the tamed local clock signal, so that even if the sending card is disconnected from the next-level sending card due to some abnormalities, the synchronization between the sending card and the next-level sending card will not disappear instantly, and after the link between the sending card and the next-level sending card is restored, the synchronization will also be restored based on the clock signal sent to the next-level sending card, so that in the process of the link between the sending card and the next-level sending card being terminated due to an abnormality and then being restored, the display synchronization will not be affected, so that the display smoothness of the LED display can be improved.

[0025] In some embodiments, the main control module is connected to the main control module of the upper-level sending card of the cascade via a data link.

[0026] Based on this embodiment, the main control module is also connected to the main control module of the upper-level sending card through a data link, so that the transmission of related data can be achieved through the data link. By adopting a special data link, the efficiency of data transmission can be improved.

[0027] In some embodiments, the main control module is connected to the main control module of the next-stage sending card in the cascade via a data link.

[0028] Based on this embodiment, the main control module is also connected to the main control module of the next-level sending card in cascade via a data link, so that the transmission of related data can be achieved through the data link. By adopting a dedicated data link, the efficiency of data transmission can be improved.

[0029] In some embodiments, the data link comprises an optical fiber or a cable.

[0030] In a second aspect, the present application further provides a sending card for an LED display screen, wherein the sending card comprises: a main control module, a second communication module connected to the main control module, and a crystal oscillator; the second communication module of the sending card is connected to the next-level sending card of the cascade through an Ethernet transmission link;

[0031] The crystal oscillator is used to provide a first clock signal to the main control module;

[0032] The main control module is further configured to send a second clock signal to the second communication module based on the first clock signal;

[0033] The second communication module is used to send the second clock signal to the next-level sending card in the cascade through Ethernet data. The second clock signal is used by the next-level sending card in the cascade to tame the local clock signal of the next-level sending card, and drive the LED signal display based on the tamed local clock signal.

[0034] Based on this embodiment, after the main control module of the sending card sends the second clock signal to the second communication module based on the received first clock signal, the second communication module sends the second clock signal to the next-level sending card in the cascade, so that the local clock signal of the next-level sending card in the cascade can be tamed by the second clock signal, so that the next-level sending card can drive the LED signal display based on the tamed local clock signal, so that even if the sending card is disconnected from the next-level sending card due to some abnormalities, the synchronization between the sending card and the next-level sending card will not disappear instantly, and after the link between the sending card and the next-level sending card is restored, the synchronization will also be restored based on the clock signal sent to the next-level sending card, so that in the process of the link between the sending card and the next-level sending card being terminated due to an abnormality and then being restored, the display synchronization will not be affected, so that the display smoothness of the LED display can be improved.

[0035] In some embodiments, the main control module is connected to the main control module of the next-stage sending card in the cascade via a data link.

[0036] Based on this embodiment, the main control module is also connected to the main control module of the next-level sending card in cascade via a data link, so that the transmission of related data can be achieved through the data link. By adopting a dedicated data link, the efficiency of data transmission can be improved.

[0037] In some embodiments, the data link comprises an optical fiber or a cable.

[0038] In a third aspect, the present application further provides a control system for an LED display screen, wherein the control system comprises a master sending card and a plurality of slave sending cards in any of the above embodiments cascade-connected to the master sending card, wherein any two adjacent sending cards are connected via an Ethernet transmission link;

[0039] The master sending card is used to send the first clock signal generated locally by the master sending card to the next-stage sending card in the cascade through the Ethernet transmission link;

[0040] The slave sending card is used to recover the third clock signal from the Ethernet data received by the upper-level sending card in the cascade, and to tame the clock signal locally generated by the slave sending card based on the third clock signal, and to drive the LED signal display based on the tamed local clock signal, and in the case of the existence of the lower-level slave sending card in the cascade, send the tamed local clock signal to the lower-level sending card in the cascade through the Ethernet transmission link.

[0041] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0043] Figure 1 A schematic diagram of the connection of synchronization signal lines between multiple existing sending card devices;

[0044] Figure 2 It is a structural block diagram of a sending card of an LED display screen in one embodiment;

[0045] Figure 3 It is a structural block diagram of a sending card of an LED display screen in another embodiment;

[0046] Figure 4 It is a structural block diagram of a sending card of an LED display screen in another embodiment;

[0047] Figure 5 It is a structural block diagram of a sending card of an LED display screen in another embodiment;

[0048] Figure 6 FIG. 1 is a schematic diagram of a cascade connection of two sending cards in an embodiment. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0050] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "connection" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0057] At present, the control system of LED display usually requires multiple sending cards to be cascaded, and each sending card corresponds to a receiving card, which is responsible for driving the LED light board. When multiple sending cards are cascaded, it is necessary to ensure that the sending cards can display synchronously, that is, they need to display the same frame at the same time to avoid the problem of screen tearing when the entire LED display is displayed.

[0058] refer to Figure 1 As shown, some existing methods for achieving synchronization between multiple sending card devices are to set a special synchronization signal line between two cascaded sending cards, and to achieve synchronization of the synchronization clocks between the cascaded multiple sending cards through the synchronization signal line. It sets one of the multiple cascaded sending card devices as a master device, and the remaining sending card devices are set as slave devices. The slave devices obtain the field synchronization signal from the master device, and use the field synchronization signal as a synchronized clock signal, and transmit the synchronized clock signal serially between the sending card devices, usually through a BNC interface to achieve the transmission of the synchronized clock signal. In addition, each sending card device is also connected through a network cable to achieve the transmission of control commands, so that the master control host can configure the system conveniently.

[0059] When performing LED display, the signal source is connected to the main sending card, and the main sending card loops out the signal source to the slave sending card at the same time. The main sending card and the slave sending card crop the image according to the display area they carry, crop the area they are responsible for displaying, and complete the processing of video data. Since the display screen is carried by multiple devices, it is necessary to ensure the display synchronization between devices. The main sending card transmits the field synchronization signal through the BNC interface, and the slave sending card drives the LED display based on the received field synchronization signal, thereby realizing the display synchronization of the content displayed between the two sending cards.

[0060] In this way, if the link of the synchronization signal ages and has poor contact, the slave device will have abnormal display such as black screen or flashing. On the other hand, it needs to use a separate physical transmission link to transmit the synchronization signal, which will increase the extra cost and complexity of wire wiring.

[0061] After research, it was found that the clock signal of the slave sending card can be tamed by the clock signal of the master sending card, and the display of the LED display can be driven based on the clock signal of the slave sending card, thereby reducing abnormal situations such as black screen and flicker. In addition, the control instructions and the synchronized clock signal can be transmitted on the same transmission line to reduce the line cost and the complexity of wire wiring.

[0062] refer to Figure 2Some embodiments of the present application provide a sending card for an LED display screen, comprising: a main control module 201, a first communication module 202 and a crystal oscillator 203 connected to the main control module 201; the first communication module 202 of the sending card is connected to the upper-level sending card (cascaded) via an Ethernet transmission link Figure 2 ) connection.

[0063] The crystal oscillator 203 is used to provide a first clock signal CLK1 to the main control module;

[0064] The first communication module 202 is used to recover the third clock signal CLK3 from the Ethernet data received by the upper-level sending card of the cascade connection, and send the recovered third clock signal to the main control module 201;

[0065] The main control module 201 is used to tame the first clock signal based on the third clock signal, and drive the LED signal display based on the tamed first clock signal.

[0066] A crystal oscillator, also known as a crystal oscillator, is an electronic oscillator that uses a crystal as a frequency selection element to obtain the inverse piezoelectric effect. It is generally made of a quartz crystal with very low electrical loss that is precisely cut and ground, plated with electrodes, and welded with leads. Their oscillation frequency is closely related to their shape, material, cutting direction, etc. Since the chemical properties of quartz crystals are very stable, the thermal expansion coefficient is very small, and their oscillation frequency is also very stable. Therefore, a crystal oscillator can usually be used to generate a clock signal to achieve the generation of a relatively stable clock signal.

[0067] The first communication module, in the embodiment of the present application, is a communication module used by the sending card to communicate with the cascaded upper-level sending card. The cascaded upper-level sending card refers to the upper-level sending card directly connected to the current sending card among the multiple cascaded sending cards. Taking the cascaded sending cards as A, B, C, D... as an example, the cascaded upper-level sending card of sending card B is sending card A, the cascaded upper-level sending card of sending card C is sending card B, and the rest are similar.

[0068] In the embodiment of the present application, the clock signal generated by the local crystal oscillator of the sending card is named as the first clock signal, and the first clock signal can be used to control the operation of the main control module. The clock signal recovered by the first communication module of the sending card from the Ethernet data received by the cascaded upper-level sending card is called the third clock signal, and the way in which the first communication module recovers the third clock signal CLK3 from the Ethernet data received by the cascaded upper-level sending card is not limited.

[0069] The specific implementation method of the main control module is not limited, such as FPGA (Field-Programmable Gate Array, field programmable gate array), etc., but not limited to this.

[0070] Based on the sending card of the present embodiment, after receiving the third clock signal sent by the cascaded upper-level sending card, the first clock signal of the local sending card is tamed based on the third clock signal. Since the first clock signal generated locally by the sending card is tamed by the third clock signal of the cascaded upper-level sending card, the clock signal generated locally by the sending card can be synchronized with the clock signal of the upper-level sending card, and the LED signal display is driven based on the tamed first clock signal. Therefore, even if the sending card is disconnected from the upper-level sending card due to some abnormality, the synchronization between the sending card and the upper-level sending card will not disappear instantly. After the link between the sending card and the upper-level sending card is restored, the synchronization will also be restored based on the received clock signal of the upper-level sending card. Therefore, in the process of the link between the sending card and the upper-level sending card being terminated due to an abnormality and being restored, the display synchronization will not be affected, so that the display smoothness of the LED display screen can be improved.

[0071] The implementation of the first communication module is not limited. In some embodiments, the first communication module includes a synchronous Ethernet module.

[0072] Synchronous Ethernet is a synchronization technology based on the physical layer code stream carrying and recovering frequency information. It can not only realize traditional digital communication, but also realize the clock transmission between the communicating parties, so that the clock signal between the sending cards can be transmitted through synchronous Ethernet.

[0073] Based on this embodiment, the sending card is connected to the upper level sending card via synchronous Ethernet, and a clock signal can be received from the upper level sending card via synchronous Ethernet. The method of transmitting the clock signal is simple and convenient.

[0074] In some embodiments, the first communication module is further used to parse out control instructions from Ethernet data received from the upper-level sending card of the cascade.

[0075] Based on this embodiment, the transmission and reception of clock signals and control instructions can be realized simultaneously through the first communication module, and there is no need to separately set up the transmission line of the control instruction and the transmission line of the clock signal, which saves line resources, simplifies the wiring cost between the sending cards, and reduces the wiring complexity. Taking the first communication module as a synchronous Ethernet module as an example, the synchronization of the clock signal can be realized through the synchronous Ethernet, and the transmission of the control command can be realized through the synchronous Ethernet, that is, the transmission of the clock signal and the control command can be realized simultaneously through a synchronous Ethernet connection line, which simplifies the wiring cost between the sending cards and reduces the wiring complexity.

[0076] There is no limitation on the manner in which the main control module 201 tames the first clock signal based on the third clock signal. In some embodiments, the main control module 201 is used to generate a field synchronization signal based on the third clock signal, and use the first clock signal and the field synchronization signal to perform phase detection processing to obtain phase error data, and tame the first clock signal based on the phase error data.

[0077] The field synchronization signal (Vsync) is a signal that needs to be output to the display after a frame is displayed. It is used to notify the display that a frame has ended, clear the screen and start displaying a new frame. The display of the display can be driven by the field synchronization signal.

[0078] In the case where the sending card is synchronized with the clock of the upper-level sending card in the cascade, the first clock signal and the third clock signal should be the same. Therefore, the field synchronization signal generated based on the third clock signal should be of the same frequency as the first clock signal or have a small deviation. Therefore, the first clock signal and the field synchronization signal can be phase-detected to obtain phase error data to evaluate the degree of deviation between the first clock signal and the third clock signal, and then taming processing can be performed on this basis.

[0079] Phase detection refers to identifying the phase difference between two input signals, and phase error data can be obtained through the phase difference obtained by phase detection.

[0080] Based on this embodiment, the main control module generates a field synchronization signal based on the third clock signal received from the previous-level sending card, uses the first clock signal and the field synchronization signal to perform phase detection processing to obtain phase error data, and then tames the first clock signal based on the phase error data, so that the first clock signal can be tamed based on the difference between the first clock signal of the sending card and the third clock signal of the previous-level sending card.

[0081] The type of the crystal oscillator 203 is not limited, for example, it can be a common crystal oscillator, a temperature-compensated crystal oscillator, a constant temperature crystal oscillator, a voltage-controlled crystal oscillator, etc.

[0082] Taking the crystal oscillator 203 as a voltage-controlled crystal oscillator as an example, in some embodiments, the main control module 201 is used to adjust the reference voltage of the crystal oscillator 203 based on the phase error data so that the first clock signal output by the crystal oscillator 203 is phase-locked with the third clock signal to tame the first clock signal.

[0083] A voltage-controlled crystal oscillator (VCXO) is a crystal oscillator that can change the output frequency of the crystal oscillator by adjusting the external voltage. Therefore, when the first clock signal is tamed, after obtaining the phase error data, the main control adjusts the reference voltage of the crystal oscillator through the phase error data. By adjusting the reference voltage of the crystal oscillator, the first clock signal output by the crystal oscillator is phase-locked with the third clock signal of the previous card, thereby achieving the taming of the first clock signal.

[0084] In some embodiments, reference Figure 3 As shown, the sending card further includes a digital-to-analog converter 204 connected to the main control module 210 and the crystal oscillator 203;

[0085] The main control module 201 adjusts the digital-to-analog converter 204 based on the phase error data to adjust the reference voltage of the crystal oscillator.

[0086] The digital-to-analog converter, also known as the D / A converter, or DAC for short, is a device that converts digital quantities into analog quantities. Through the digital converter, the digital quantity can be converted into a DC voltage. Therefore, the DC voltage can be output through the digital-to-analog converter 204 based on the phase error data to adjust the reference voltage of the crystal oscillator and realize automatic adjustment of the voltage of the crystal oscillator.

[0087] Based on this embodiment, the sending card is provided with a digital-to-analog converter connected between the main control module and the crystal oscillator, and the digital-to-analog converter is adjusted based on the obtained phase error data to adjust the reference voltage of the crystal oscillator, thereby making the first clock signal output by the crystal oscillator phase-locked with the third clock signal of the previous-level sending card, thereby achieving the taming of the first clock signal, thereby enabling the precise adjustment of the first clock signal of the sending card.

[0088] In some embodiments, reference Figure 4 As shown, the sending card further includes: a second communication module 205 connected to the main control module 201; the second communication module 205 of the sending card is connected to the next level sending card of the cascade through an Ethernet transmission link;

[0089] The main control module 201 is further configured to send a second clock signal to the second communication module 205 based on the first clock signal;

[0090] The second communication module 205 is used to send the second clock signal to the next-level sending card in the cascade through Ethernet data. The second clock signal is used by the next-level sending card in the cascade to tame the local clock signal of the next-level sending card and drive the LED signal display based on the tamed local clock signal.

[0091] The connection mode of the sending card with the sending card at the previous stage of the cascade connection is the same as the connection mode of the sending card at the next stage of the cascade connection.

[0092] Based on this embodiment, after the main control module of the sending card sends the second clock signal to the second communication module based on the received first clock signal, the second communication module sends the second clock signal to the next-level sending card in the cascade, so that the local clock signal of the next-level sending card in the cascade can be tamed by the second clock signal, so that the next-level sending card can drive the LED signal display based on the tamed local clock signal, so that even if the sending card is disconnected from the next-level sending card due to some abnormalities, the synchronization between the sending card and the next-level sending card will not disappear instantly, and after the link between the sending card and the next-level sending card is restored, the synchronization will also be restored based on the clock signal sent to the next-level sending card, so that in the process of the link between the sending card and the next-level sending card being terminated due to an abnormality and then being restored, the display synchronization will not be affected, so that the display smoothness of the LED display can be improved.

[0093] In some embodiments, the main control module is connected to the main control module of the upper-level sending card of the cascade via a data link.

[0094] In the embodiment of the present application, the data link is a link used to transmit data displayed on a display screen, such as video data.

[0095] Based on this embodiment, the main control module is also connected to the main control module of the upper-level sending card through a data link, so that the transmission of related data can be achieved through the data link. By adopting a special data link, the efficiency of data transmission can be improved.

[0096] In some embodiments, the main control module is connected to the main control module of the next-stage sending card in the cascade via a data link.

[0097] Based on this embodiment, the main control module is also connected to the main control module of the next-level sending card in cascade via a data link, so that the transmission of related data can be achieved through the data link. By adopting a dedicated data link, the efficiency of data transmission can be improved.

[0098] The specific real-time mode of the data link is not limited. In some embodiments, the data link includes an optical fiber or a cable.

[0099] Optical fiber, whose full name is optical fiber, is a bendable pure glass fiber made of glass or plastic. Data is transmitted through optical fiber with fast signal transmission speed and stable transmission quality, which can reduce the loss of transmitted data and help improve the accuracy of transmitted data.

[0100] Cables are usually more suitable for short-distance communication, and LED screens are set up adjacent to each other when displaying a picture together. Therefore, transmitting data via cables can also meet the needs of transmitting video and other data.

[0101] It is understandable that the data link may also be in other forms, which can be selected and set based on actual technical requirements.

[0102] In some embodiments, reference Figure 5 As shown, the present application also provides a sending card for an LED display screen, wherein the sending card comprises: a main control module 201, a second communication module 205 and a crystal oscillator 203 connected to the main control module 201; the second communication module 205 of the sending card is connected to the next level sending card of the cascade through an Ethernet transmission link;

[0103] The crystal oscillator 203 is used to provide a first clock signal to the main control module;

[0104] The main control module 201 is further configured to send a second clock signal to the second communication module 205 based on the first clock signal;

[0105] The second communication module 205 is used to send the second clock signal to the next-level sending card in the cascade through Ethernet data. The second clock signal is used by the next-level sending card in the cascade to tame the local clock signal of the next-level sending card and drive the LED signal display based on the tamed local clock signal.

[0106] In the embodiment of the present application, the clock signal sent by the main control module of the sending card to the second communication module is called the second clock signal, and the operation of the second communication module can be controlled by the second control signal.

[0107] Based on this embodiment, after the main control module of the sending card sends the second clock signal to the second communication module based on the received first clock signal, the second communication module sends the second clock signal to the next-level sending card in the cascade, so that the local clock signal of the next-level sending card in the cascade can be tamed by the second clock signal, so that the next-level sending card can drive the LED signal display based on the tamed local clock signal, so that even if the sending card is disconnected from the next-level sending card due to some abnormalities, the synchronization between the sending card and the next-level sending card will not disappear instantly, and after the link between the sending card and the next-level sending card is restored, the synchronization will also be restored based on the clock signal sent to the next-level sending card, so that in the process of the link between the sending card and the next-level sending card being terminated due to an abnormality and then being restored, the display synchronization will not be affected, so that the display smoothness of the LED display can be improved.

[0108] In some embodiments, the main control module is connected to the main control module of the next-stage sending card in the cascade via a data link.

[0109] Based on this embodiment, the main control module is also connected to the main control module of the next-level sending card in cascade via a data link, so that the transmission of related data can be achieved through the data link. By adopting a dedicated data link, the efficiency of data transmission can be improved.

[0110] The specific real-time mode of the data link is not limited. In some embodiments, the data link includes an optical fiber or a cable.

[0111] Based on the sending card described above, the embodiment of the present application further provides a control system for an LED display screen, wherein the control system includes a master sending card and a plurality of slave sending cards cascade-connected to the master sending card, wherein any two adjacent sending cards are connected via an Ethernet transmission link. Figure 5 The structure of the sending card in the embodiment shown may also include Figure 4 The structure of the sending card in the embodiment shown in the figure is that the sending card may only have Figure 2 , 3 The structure of the sending card in the embodiment shown may also include Figure 4 The structure of the sending card of the embodiment shown.

[0112] In order to improve the connection convenience of the control system and the adaptability of the sending card, the master sending card and the slave sending card can have the same structure, for example, both can be as follows Figure 4 The structure of the sending card of the embodiment shown.

[0113] The master sending card is used to send the first clock signal generated locally by the master sending card to the next-stage sending card in the cascade through the Ethernet transmission link;

[0114] The slave sending card is used to recover the third clock signal from the Ethernet data received by the upper-level sending card in the cascade, and to tame the clock signal locally generated by the slave sending card based on the third clock signal, and to drive the LED signal display based on the tamed local clock signal, and in the case of the existence of the lower-level slave sending card in the cascade, send the tamed local clock signal to the lower-level sending card in the cascade through the Ethernet transmission link.

[0115] It can be understood that, in the case where the slave sending card is the optimal first-level sending card in the cascade, it can recover the third clock signal only from the Ethernet data received by the previous-level sending card in the cascade, and tame the clock signal locally generated by the slave sending card based on the third clock signal, and drive the LED signal display based on the tamed local clock signal.

[0116] Other technical features of each sending card in the control system are the same as those in the above-mentioned embodiment and will not be described in detail here.

[0117] Based on the above examples, some specific examples are described in detail below. Figure 6 In the figure, two adjacent sending cards A and B in the cascaded sending cards in the control system are taken as an example for explanation.

[0118] Combination Figure 6 In the example shown, the second communication module of the sending card A used to connect to the next-level sending card is connected to the first communication module of the sending card B used to connect to the previous-level sending card. It can be understood that in actual application, the first communication module and the second communication module can also be the same setting. For example, the sending card A can be connected to any one of the first communication module and the second communication module of the sending card B through any one of the first communication module and the second communication module, as long as the sending card A and the sending card B can know or analyze the first communication module and the second communication module, respectively connected to the cascaded previous-level sending card or the cascaded next-level sending card. In the embodiment of the present application, the communication module of the sending card connected to the next-level sending card is called the second communication module, and the communication module connected to the previous-level sending card is called the first communication module.

[0119] Combination Figure 6 As shown, if the sending card A is the master device, its first communication module is not connected to the upper-level sending card, and the third clock signal CLK3-A shown in the figure does not exist. If the sending card is not the master device, its first communication module is cascade-connected with the upper-level sending card, and the third clock signal CLK3-A sent by the upper-level sending card can be received and parsed through the first communication module, and the parsed third clock signal CLK3-A is sent to the main control module.

[0120] The crystal oscillator of the sending card A generates and outputs the first clock signal CLK1-A to the main control module. The main control module works based on the first clock signal CLK1-A, for example, driving the LED signal display, and provides the second clock signal CLK2-A to the second communication module. It can be understood that in the same industry, the first clock signal CLK1-A and the second clock signal CLK2-A are usually the same. Among them, if the sending card is not the main device, the crystal oscillator of the sending card A generates and outputs the first clock signal CLK1-A, which is a clock signal tamed by the third clock signal CLK3-A.

[0121] The second communication module transmits the second clock signal CLK2-A to the next level sending card through the communication link. Figure 6 Sending card B shown.

[0122] The first communication module of the sending card B receives the clock signal transmitted by the sending card A, analyzes it to obtain the third clock signal CLK3-B, and uses the third clock signal CLK3-B to tame the first clock signal CLK1-B generated by the local crystal oscillator of the sending card B. The crystal oscillator of the sending card B generates and outputs the first clock signal CLK1-B to the main control module, and the main control module works based on the first clock signal CLK1-B, for example, driving the LED signal display.

[0123] If the sending card B is not the last sending card of the cascade, the main control module of the sending card B sends the second clock signal CLK2-B to the second communication module of the sending card B, so as to transmit it to the sending card of the next level, and so on. If the sending card B is the last sending card of the cascade, the main control module of the sending card B does not need to send the second clock signal CLK2-B to the second communication module of the sending card B.

[0124] In some embodiments, reference Figure 6 As shown, the sending card may further include a management unit connected to the main control module and the communication module (including the first communication module and the second communication module), and the management unit may be used to manage the sending card device, such as the management of the communication between the sending card devices, the management of the communication between the sending card and the generated application, etc., but is not limited thereto.

[0125] The specific implementation method of the management unit is not limited. In some embodiments, it can be implemented through an ARM controller, but it is not limited to this.

[0126] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above 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.

[0127] 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 understood as limiting the scope of the present 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 present application shall be subject to the attached claims.

Claims

1. A sending card for an LED display, characterized in that: The sending card comprises: a main control module, a first communication module connected to the main control module and a crystal oscillator; the first communication module of the sending card is connected to the upper-level sending card of the cascade through an Ethernet transmission link; The crystal oscillator is used to provide a first clock signal to the main control module; The first communication module is used to recover the third clock signal from the Ethernet data received by the upper-level sending card of the cascade, and send the recovered third clock signal to the main control module; The main control module is used to tame the first clock signal based on the third clock signal, and drive the LED signal display based on the tamed first clock signal.

2. The sending card according to claim 1, characterized in that: The first communication module includes a synchronous Ethernet module.

3. The sending card according to claim 2, characterized in that: The first communication module is also used to parse out control instructions from Ethernet data received by the upper-level sending card in the cascade.

4. The sending card according to claim 1, characterized in that: The main control module is used to generate a field synchronization signal based on the third clock signal, perform phase detection processing with the first clock signal and the field synchronization signal to obtain phase error data, and tame the first clock signal based on the phase error data.

5. The sending card according to claim 4, characterized in that: The main control module is used to adjust the reference voltage of the crystal oscillator based on the phase error data so that the first clock signal output by the crystal oscillator is phase-locked with the third clock signal to tame the first clock signal.

6. The sending card according to claim 5, characterized in that: The sending card also includes a digital-to-analog converter connected to the main control module and the crystal oscillator; The main control module adjusts the digital-to-analog converter based on the phase error data to adjust the reference voltage of the crystal oscillator.

7. The sending card according to any one of claims 1 to 5, characterized in that: The sending card further comprises: a second communication module connected to the main control module; the second communication module of the sending card is connected to the next level sending card of the cascade via an Ethernet transmission link; The main control module is further configured to send a second clock signal to the second communication module based on the first clock signal; The second communication module is used to send the second clock signal to the next-level sending card in the cascade through Ethernet data. The second clock signal is used by the next-level sending card in the cascade to tame the local clock signal of the next-level sending card, and drive the LED signal display based on the tamed local clock signal.

8. The sending card according to any one of claims 1 to 5, characterized in that: The main control module is connected to the main control module of the upper-level sending card of the cascade via a data link.

9. A sending card for an LED display screen, characterized in that: The sending card comprises: a main control module, a second communication module connected to the main control module and a crystal oscillator; the second communication module of the sending card is connected to the next level sending card of the cascade through an Ethernet transmission link; The crystal oscillator is used to provide a first clock signal to the main control module; The main control module is further configured to send a second clock signal to the second communication module based on the first clock signal; The second communication module is used to send the second clock signal to the next-level sending card in the cascade through Ethernet data. The second clock signal is used by the next-level sending card in the cascade to tame the local clock signal of the next-level sending card, and drive the LED signal display based on the tamed local clock signal.

10. A control system for an LED display screen, characterized in that: A method comprising: comprising a master sending card and a plurality of slave sending cards according to any one of claims 1 to 7 which are cascade-connected to the master sending card, wherein any two adjacent sending cards are connected via an Ethernet transmission link; The master sending card is used to send the first clock signal generated locally by the master sending card to the next-stage sending card in the cascade through the Ethernet transmission link; The slave sending card is used to recover the third clock signal from the Ethernet data received by the upper-level sending card in the cascade, and to tame the clock signal locally generated by the slave sending card based on the third clock signal, and to drive the LED signal display based on the tamed local clock signal, and in the case of the existence of the lower-level slave sending card in the cascade, send the tamed local clock signal to the lower-level sending card in the cascade through the Ethernet transmission link.

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