Light emitting diode LED drive circuit, light emitting diode LED display system

Abstract

The present invention discloses a light emitting diode (LED) driving circuit and a light emitting diode (LED) display system. The driving circuit includes: a differential interface subcircuit for receiving a differential signal; a display logic control subcircuit connected to the differential interface subcircuit for extracting first logic control data for LED display from the differential signal, and sending the first logic control data to a first controller, so that the first controller controls the on / off state of a second controller based on the first logic control data; a display control switch subcircuit connected to the differential interface subcircuit for extracting second logic control data for LED display from the differential signal, and sending the second logic control data to a third controller, so that the third controller controls the on / off state of a fourth controller based on the second logic control data. The present invention solves the technical problem that the display module PCB design of the LED driver chip in the related art is relatively complex and costly.

Description

Technical Field

[0001] The present invention relates to the technical field of LED drive control, and in particular to a light emitting diode (LED) drive circuit and a light emitting diode (LED) display system. Background Art

[0002] At present, the communication control method of the existing light emitting diode (LED) driver chip is the serial peripheral interface (SPI). Figure 1 It is a schematic diagram of the SPI interface of the communication control method of the LED driver chip according to the prior art, specifically showing as follows Figure 1 As shown, the communication control mode of the existing LED driver chip, the communication control mode of the existing MOS integrated IC, and the communication control mode of the existing independent MOS are shown. The existing LED driver chip is a low-speed TTL communication control mode, including five signals: DCLK, GCLK, SDI, SDO, and LE; among them, DCLK is responsible for the transmission and synchronization of data SDI, and several LED driver chips can share it; SDI is a data signal, including the control command of the chip and the display control data of the chip driving the LED; SDO is the serial output data of the chip, which is responsible for transmitting the data to the next-level LED driver chip; GCLK is the on and off control signal of the LED control port of the chip to realize the control of the LED opening time; LE is the data latch signal of the chip, which controls the loading function during the data transmission process.

[0003] Combined with the above Figure 1 It can be seen that in the existing PCB layout, the circuits are relatively complex and occupy a relatively large PCB area.

[0004] With regard to the problem that the display module PCB design of the LED driver chip in the above-mentioned related technologies is relatively complex and costly, no effective solution has been proposed so far. Summary of the invention

[0005] The embodiments of the present invention provide a light emitting diode (LED) driving circuit and a light emitting diode (LED) display system to at least solve the technical problem that the display module PCB design of the LED driving chip in the related art is relatively complex and costly.

[0006] According to one aspect of an embodiment of the present invention, there is provided a light emitting diode (LED) driving circuit, which is integrated on an LED driving chip and includes: a differential interface subcircuit, which is used to receive a differential signal; a display logic control subcircuit, which is connected to the differential interface subcircuit and is used to extract first logic control data for LED display from the differential signal, and send the first logic control data to a first controller, so that the first controller controls the on / off state of a second controller based on the first logic control data; a display control switch subcircuit, which is connected to the differential interface subcircuit and is used to extract second logic control data for LED display from the differential signal, and send the second logic control data to a third controller, so that the third controller controls the on / off state of a fourth controller based on the second logic control data.

[0007] Optionally, the differential interface sub-circuit is further used to connect the LED driver chip to an LED driver chip adjacent to the LED driver chip in the LED array, so as to enable communication between the multiple driver chips in the LED array.

[0008] Optionally, the differential signal includes: a first differential signal, a second differential signal, and a third differential signal, wherein the first differential signal is a clock differential signal for controlling the display timing of the LED; the second differential signal is a signal corresponding to the first logic control data; and the third differential signal is a signal corresponding to the second logic control data.

[0009] Optionally, the first logic control data includes: three primary color light RGB logic control data for the LED display, and rhythm control data for the LED display.

[0010] Optionally, the display logic control subcircuit is further used to extract the RGB logic control data from the second differential signal based on the transmission relationship between the first differential signal and the second differential signal, and store the RGB logic control data in an RGB buffer.

[0011] Optionally, the display logic control subcircuit is also used to extract the beat control data from the second differential signal based on the transmission relationship between the first differential signal and the second differential signal, and transmit the beat control data to the first controller, wherein the first controller is a display control metronome.

[0012] Optionally, the display control metronome transmits the RGB logic control data stored in the RGB buffer to the constant current device according to the beat control data.

[0013] Optionally, the constant current device is used to generate an LED display logic current based on the RGB logic control data, wherein the LED display logic current is used to control the on / off state of the second controller, and the second controller is an RGB switch controller.

[0014] Optionally, the second logic control data includes: switch logic control data for the LED display, and switch rhythm data for the LED display.

[0015] Optionally, the display control switch sub-circuit is further used to extract the switch logic control data from the third differential signal based on the transmission relationship between the first differential signal and the third differential signal, and store it in a switch state buffer.

[0016] Optionally, the display logic control subcircuit is also used to extract the switch beat data from the third differential signal based on the transmission relationship between the first differential signal and the third differential signal, and transmit the switch beat data to the third controller, wherein the third controller is a display switch metronome.

[0017] Optionally, the display switch metronome transmits the switch logic control data to the fourth controller according to the switch beat data to control the on / off state of the MOS tube in the LED, wherein the fourth controller is a switch state controller.

[0018] According to another aspect of the embodiments of the present invention, a light emitting diode (LED) display system is provided, comprising: an LED array; and any one of the light emitting diode (LED) driving circuits described above, used to drive the LED array.

[0019] In the embodiment of the present invention, a differential interface subcircuit is used to receive a differential signal; a display logic control subcircuit is connected to the differential interface subcircuit, and is used to extract first logic control data for LED display from the differential signal, and send the first logic control data to the first controller, so that the first controller controls the on / off state of the second controller based on the first logic control data; a display control switch subcircuit is connected to the differential interface subcircuit, and is used to extract second logic control data for LED display from the differential signal, and send the second logic control data to the third controller, so that the third controller controls the on / off state of the fourth controller based on the second logic control data. The light emitting diode LED driving circuit provided by the embodiment of the present invention realizes the application of the differential communication method to the LED driving chip to drive the display of the LED. By integrating the differential communication method with the display control logic circuit and the display control switch circuit, the design of the LED display module PCB is simplified, and the PCB cost is also reduced, achieving the technical effect of reducing the complexity of the display module PCB design of the LED driving chip, thereby solving the technical problem that the display module PCB design of the LED driving chip in the related art is relatively complex and costly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 It is a schematic diagram of the SPI interface of the communication control method of the LED driver chip according to the prior art;

[0022] Figure 2 is a schematic diagram of a light emitting diode LED driving circuit according to an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of the interface differential signal data relationship of the differential interface sub-circuit according to an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of a display logic control subcircuit according to an embodiment of the present invention;

[0025] Figure 5 is a data structure diagram of a display control metronome and an RGB buffer according to an embodiment of the present invention;

[0026] Figure 6 is a schematic diagram of a display control switch subcircuit according to an embodiment of the present invention;

[0027] Figure 7is a data structure diagram showing a switch metronome and a switch status buffer according to an embodiment of the present invention;

[0028] Figure 8 Schematic diagram of an optional light emitting diode LED driving circuit according to the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] To facilitate understanding, some nouns or terms that appear in the embodiments of the present invention are explained below.

[0032] Differential Signal (DS for short): It uses numerical values ​​to represent the difference between two physical quantities.

[0033] Low voltage differential signal (LVDS) is a low-swing differential signal technology that enables signals to be transmitted at a rate of several hundred Mbps on differential PCB line pairs or balanced cables. Its low voltage amplitude and low current drive output achieve low noise and low power consumption.

[0034] According to one aspect of an embodiment of the present invention, a light emitting diode (LED) driving circuit is provided, which is integrated on an LED driving chip. Figure 2 is a schematic diagram of a light emitting diode LED driving circuit according to an embodiment of the present invention, such as Figure 2As shown, the light emitting diode LED driving circuit includes: a differential interface subcircuit 21, a display logic control subcircuit 23, and a display control switch subcircuit 25. The light emitting diode LED driving circuit is described below.

[0035] The differential interface subcircuit 21 is used to receive differential signals.

[0036] The display logic control subcircuit 23 is connected to the differential interface subcircuit 21, and is used to extract the first logic control data for LED display from the differential signal, and send the first logic control data to the first controller, so that the first controller controls the opening and closing state of the second controller based on the first logic control data.

[0037] The display control switch subcircuit 25 is connected to the differential interface subcircuit 21, and is used to extract the second logic control data for LED display from the differential signal, and send the second logic control data to the third controller, so that the third controller controls the opening and closing state of the fourth controller based on the second logic control data.

[0038] As can be seen from the above, in the embodiment of the present invention, by integrating the light emitting diode LED driving circuit on the LED driving chip, the differential signal is received by using the differential interface sub-circuit; and the first logic control data for LED display is extracted from the differential signal by using the display logic control sub-circuit connected to the differential interface sub-circuit, and the first logic control data is sent to the first controller, so that the first controller controls the on and off state of the second controller based on the first logic control data; and the second logic control data for LED display is extracted from the differential signal by using the display control switch sub-circuit connected to the differential interface sub-circuit, and the second logic control data is sent to the third controller, so that the third controller controls the on and off state of the fourth controller based on the second logic control data, thereby realizing the application of the differential communication method to the LED driving chip to drive the display of the LED. By integrating the differential communication method with the display control logic circuit and the display control switch circuit, the design of the LED display module PCB is simplified, and the PCB cost is also reduced, thereby achieving the technical effect of reducing the complexity of the display module PCB design of the LED driving chip.

[0039] Therefore, the light emitting diode (LED) driving circuit provided by the embodiment of the present invention solves the technical problem of the complicated and high-cost design of the display module PCB of the LED driving chip in the related art.

[0040] In an optional embodiment, the differential interface subcircuit is further used to connect the LED driver chip to an LED driver chip adjacent to the LED driver chip in the LED array, so as to enable communication between the multiple driver chips in the LED array.

[0041] In this embodiment, the differential interface subcircuit can be used to cascade multiple LED driver chips in the LED array to achieve display control of the LED array.

[0042] Among them, the above-mentioned differential signal includes: a first differential signal, a second differential signal, and a third differential signal, wherein the first differential signal is a clock differential signal, which is used to control the display timing of the LED; the second differential signal is a signal corresponding to the first logic control data; and the third differential signal is a signal corresponding to the second logic control data.

[0043] Figure 3 is a schematic diagram of the interface differential signal data relationship of the differential interface sub-circuit according to an embodiment of the present invention, such as Figure 3 As shown, the differential interface subcircuit can be mainly responsible for connecting different driver chips (i.e., LED driver chips) in series to realize the communication interconnection of several driver chips; wherein, DS1 is a clock differential signal (i.e., a first differential signal), DS2 is a data 1 differential signal (i.e., a second differential signal), where data 1 can be the display content of the LED, DS3 is a data 2 differential signal (i.e., a third differential signal), where data 2 is the RGB display switch control data; CLK is a clock signal (i.e., a first differential signal). In the figure, DS1 / DSL1 / CLK are differential clock signals at different positions, where DS1 represents an interface outside the LED driver chip, and DSL1 represents an interface inside the LED driver chip; DS2 / DSL2 / DATA1 are differential data signals at different positions, where DS2 is at the chip external interface, and DSL2 is inside the chip; DS3 / DSL3 / DATA2 are also differential data signals at different positions, where DS3 is at the chip external interface, and DSL3 is inside the chip. Command_a represents a control signal for RGB display content for LED display transmitted in data1 (ie, data 1) signal; Command_b represents a control signal for LED switch transmitted in data2 (ie, data 2) signal.

[0044] exist Figure 3 DS1 and DS2 can be regarded as a group of processing signals, and DS1 and DS3 can also be regarded as a group of processing signals. RGB corresponds to 8 bits 0-7 respectively, where each bit can be represented by a state flag 0 or 1, 1 means on, and 0 means off. Here, scan_a, scan_b, and scan_c represent three groups of switch signals for LED switches transmitted in the data2 signal.

[0045] It should be noted that the differential signal in the embodiment of the present invention is preferably a low voltage differential signal LVDS.

[0046] In the embodiment of the present invention, the first logic control data includes: three primary color light RGB logic control data for LED display, and rhythm control data for LED display.

[0047] In addition, the first logic control data also includes: display content of LED, that is, RGB display content control data.

[0048] In one aspect, the display logic control subcircuit is also used to extract RGB logic control data from the second differential signal based on the transmission relationship between the first differential signal and the second differential signal, and store the RGB logic control data in the RGB buffer.

[0049] On the other hand, the display logic control subcircuit is also used to extract the beat control data from the second differential signal based on the transmission relationship between the first differential signal and the second differential signal, and transmit the beat control data to the first controller, wherein the first controller is a display control metronome.

[0050] The display control metronome transmits the RGB logic control data stored in the RGB buffer to the constant current device according to the beat control data.

[0051] It should be noted that the constant current is used to generate an LED display logic current based on the RGB logic control data, wherein the LED display logic current is used to control the on / off state of the second controller, and the second controller is an RGB switch controller.

[0052] Figure 4 is a schematic diagram of a display logic control subcircuit according to an embodiment of the present invention, such as Figure 4 As shown, the display logic control subcircuit may include: a display logic controller, which is connected to the R buffer, the G buffer and the B buffer respectively, wherein the R buffer, the G buffer and the B buffer are respectively connected to the corresponding constant current devices, and the constant current devices here are respectively connected to the corresponding LEDs to realize the control of the LED display content and the display rhythm.

[0053] In addition, in order to realize the control of LED display rhythm, the display logic control subcircuit also includes: a display control metronome, which is respectively connected to the display logic controller and the buffer, the constant current device and the switch controller to realize the above-mentioned control of the LED display content and display rhythm.

[0054] In this embodiment, the RGB control logic for LED display is extracted from DS2 by utilizing the transmission relationship between DS1 (CLK) and DS2 (DATA1), and is stored in the RGB buffer after extraction; and the control beat signal for LED display can be extracted from DS2 by utilizing the transmission relationship between DS1 (CLK) and DS2 (DATA1), and is transmitted to the display control metronome after extraction; the display control metronome transmits the control logic in the RGB display buffer to the constant current device according to the beat signal, controls the RGB constant current device to generate the LED display logic current; and at the same time controls the conduction and closing of the RGB switch controller.

[0055] Figure 5 is a data structure diagram of a display control metronome and an RGB buffer according to an embodiment of the present invention, such as Figure 5 As shown, command_a includes 8 bits of data, that is, 256 combinations, which will be transmitted to the display control metronome, RGB data for LED display, where R1 / B1 / G1 represents the first pixel, 0-7 represents the display content of each primary color, and a total of 256 display content levels.

[0056] In an optional embodiment, the second logic control data includes: switch logic control data for LED display, and switch rhythm data for LED display.

[0057] In one aspect, the display control switch subcircuit is further used to extract the switch logic control data from the third differential signal based on the transmission relationship between the first differential signal and the third differential signal, and store it in the switch state buffer.

[0058] On the other hand, the display control switch sub-circuit is also used to extract the switch beat data from the third differential signal based on the transmission relationship between the first differential signal and the third differential signal, and transmit the switch beat data to the third controller, wherein the third controller is a display switch metronome.

[0059] The display switch metronome transmits the switch logic control data to the fourth controller according to the switch beat data to control the on / off state of the MOS tube in the LED, wherein the fourth controller is a switch state controller.

[0060] Figure 6 is a schematic diagram of a display control switch subcircuit according to an embodiment of the present invention, such as Figure 6 As shown, the display control switch subcircuit may further include: a display switch logic connected to the switch state buffer; the switch state buffer may be connected to the switch state controller, so that the switch state controller controls the MOS tube (for example, Figure 6MOS1, MOS2, MOS3, MOS4, MOS5, MOS6, MOS7...MOSn).

[0061] Specifically, Figure 6 As shown, the display switch metronome is connected to the switch state controller, the switch state buffer and the display switch logic, so that the display switch logic can transmit the switch logic control data to the switch state controller according to the switch beat data to control the on and off state of the MOS tube in the LED.

[0062] In this embodiment, the switch control logic for LED display can be extracted from DS3 by utilizing the transmission relationship between DS1 (CLK) and DS3 (DATA2), and stored in the switch state buffer after extraction; the switch beat signal for LED display can be extracted from DS3 by utilizing the transmission relationship between DS1 (CLK) and DS3 (DATA2), and transmitted to the display switch metronome after extraction; the display switch metronome transmits the switch state in the switch state buffer to the switch state controller according to the beat signal, so as to control the on and off actions of the MOS.

[0063] Figure 7 It is a data structure diagram of the display switch metronome and the switch status buffer according to an embodiment of the present invention. Command_b contains 8 bits of data, that is, 256 combinations; these data will be transmitted to the display switch metronome; scan_a / b / c each contains 8 bits of data, and through the combination of a / b / c, 24 bits of switch data are realized, and these switch data will be transmitted to the switch status buffer.

[0064] Figure 8 is a schematic diagram of an optional light emitting diode LED driving circuit according to the present invention, such as Figure 8 As shown, it includes: differential interface subcircuit, display logic control subcircuit, display control switch subcircuit, and these subcircuits are integrated on the LED driver chip. The LED driver chip here can be used to drive the LED array, and its input is three sets of differential signals, such as DS1, DS2 and DS3 in the figure, and the input is used to cascade the next level LED driver chip. The above subcircuits are integrated in the same chip to realize the display driving function of the LED.

[0065] Through the light emitting diode LED driving circuit provided by the embodiment of the present invention, the differential communication method is applied to the LED driving chip; the differential communication method is integrated with the display control logic circuit and the display control switch circuit; wherein the differential communication method is preferably the LVDS communication method. The communication control method is simple; the LED display module PCB design is simple, and the required PCB cost is relatively low; the LED display module has relatively good EMI characteristics.

[0066] According to another aspect of the embodiments of the present invention, a light emitting diode (LED) display system is provided, comprising: an LED array; and any one of the light emitting diode (LED) driving circuits described above, for driving the LED array.

[0067] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0068] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0069] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0070] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0071] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0072] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc. Various media that can store program codes.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A light emitting diode (LED) driving circuit, characterized in that: Integrated on the LED driver chip, including: A differential interface subcircuit, for receiving a differential signal; A display logic control subcircuit, connected to the differential interface subcircuit, for extracting first logic control data for LED display from the differential signal, and sending the first logic control data to the first controller, so that the first controller controls the on / off state of the second controller based on the first logic control data; A display control switch subcircuit, connected to the differential interface subcircuit, for extracting second logic control data for the LED display from the differential signal, and sending the second logic control data to the third controller, so that the third controller controls the on / off state of the fourth controller based on the second logic control data; The differential signal includes: a first differential signal, a second differential signal, and a third differential signal, wherein the first differential signal is a clock differential signal for controlling the display timing of the LED; the second differential signal is a signal corresponding to the first logic control data; and the third differential signal is a signal corresponding to the second logic control data. The first logic control data includes: the three primary colors RGB logic control data for the LED display, the rhythm control data for the LED display, The second logic control data includes: switch logic control data for the LED display, switch rhythm data for the LED display, The first controller is a display control metronome, the second controller is an RGB switch controller, the third controller is a display switch metronome, and the fourth controller is a switch state controller.

2. The light emitting diode (LED) driving circuit according to claim 1, characterized in that: The differential interface subcircuit is further used to connect the LED driver chip to an LED driver chip adjacent to the LED driver chip in the LED array, so as to enable communication between the multiple driver chips in the LED array.

3. The light emitting diode (LED) driving circuit according to claim 1, characterized in that: The display logic control subcircuit is further used to extract the RGB logic control data from the second differential signal based on the transmission relationship between the first differential signal and the second differential signal, and store the RGB logic control data in the RGB buffer.

4. The light emitting diode (LED) driving circuit according to claim 3, characterized in that: The display logic control subcircuit is further used to extract the beat control data from the second differential signal based on the transmission relationship between the first differential signal and the second differential signal, and transmit the beat control data to the first controller.

5. The light emitting diode LED driving circuit according to claim 4, characterized in that: The display control metronome transmits the RGB logic control data stored in the RGB buffer to the constant current device according to the metronome control data.

6. The light emitting diode (LED) driving circuit according to claim 5, characterized in that: The constant current device is used to generate an LED display logic current based on the RGB logic control data, wherein the LED display logic current is used to control the on / off state of the second controller.

7. The light emitting diode (LED) driving circuit according to claim 1, characterized in that: The display control switch sub-circuit is further used to extract the switch logic control data from the third differential signal based on the transmission relationship between the first differential signal and the third differential signal, and store the data in a switch state buffer.

8. The light emitting diode (LED) driving circuit according to claim 7, characterized in that: The display logic control subcircuit is further used to extract the switching beat data from the third differential signal based on the transmission relationship between the first differential signal and the third differential signal, and transmit the switching beat data to the third controller.

9. The light emitting diode (LED) driving circuit according to claim 8, characterized in that: The display switch metronome transmits the switch logic control data to the fourth controller according to the switch beat data to control the on / off state of the MOS tube in the LED.

10. A light emitting diode (LED) display system, characterized in that: include: LED array; The light emitting diode (LED) driving circuit according to any one of claims 1 to 9, used to drive the LED array.

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