Full-color LED display screen driving circuit

Abstract

Disclosed in the present invention is a full-color LED display screen driving circuit, comprising a display controller, a row control module and at least two display driving units; the display controller is connected to the display driving units by means of the row control module, red-light driving ends of red-light display branches of each display driving unit being respectively connected to different red-light constant-current ports of a constant-current driving chip of the display driving unit, green-light driving ends of green-light display branches of each display driving unit being respectively connected to different green-light constant-current ports of the constant-current driving chip of the display driving unit, and blue-light driving ends of blue-light display branches of each display driving unit being respectively connected to different blue-light constant-current ports of the constant-current driving chip of the display driving unit. The present invention can effectively avoid the problem of display non-uniformity of full-color LED display screens due to local overheating.

Description

A full-color LED display driving circuit Technical Field

[0001] This invention relates to the field of LED displays, and in particular to a driving circuit for a full-color LED display. Background Technology

[0002] In existing full-color LED displays, the red, green, and blue LEDs are driven by different constant current driver chips. Under the same operating conditions, the forward voltage drops of the red, green, and blue LEDs are different, with the red LEDs having the smallest forward voltage drop. Furthermore, the conduction current of red LEDs is typically higher than that of blue and green LEDs. This results in the constant current driver chip driving the red LEDs bearing a greater additional voltage drop, making it prone to overheating during operation. This can lead to localized overheating issues in the full-color LED display, causing uneven color display and reducing the overall display quality.

[0003] In view of the above problems, it is necessary to study a full-color LED display driving circuit to overcome the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of this invention is to provide a full-color LED display driving circuit to overcome the shortcomings of the prior art.

[0005] To achieve the above objectives, the solution of the present invention is:

[0006] A full-color LED display driving circuit includes a display controller, a horizontal control module, and at least two display driving units. The horizontal control module includes multiple switching transistors, with the input of each transistor connected to a driving power supply and the control terminal of each transistor connected to the display controller. Each display driving unit includes at least one red light display branch, at least one green light display branch, at least one blue light display branch, and a constant current driving chip. Each red light display branch includes multiple red LEDs, with the anode of each red LED connected to the output of each switching transistor in the horizontal control module, and the cathode of each red LED connected to the red driving terminal of that branch. Each green light display branch includes multiple green LEDs, with the anode of each green LED connected to the output of each switching transistor in the horizontal control module, and the control terminal of each green LED connected to the control chip. The cathode is connected to the green light driving terminal of the green light display branch; each blue light display branch includes multiple blue LED beads, the anode of each blue LED bead in each blue light display branch is connected to the output terminal of each switching transistor of the horizontal control module, and the cathode of each blue LED bead in each blue light display branch is connected to the blue light driving terminal of the blue light display branch; the constant current driving chip is connected to the display controller, and the constant current driving chip has at least one red light constant current port, at least one green light constant current port, and at least one blue light constant current port; the red light driving terminal of each red light display branch of each display driving unit is connected to a different red light constant current port of the constant current driving chip of the display driving unit, the green light driving terminal of each green light display branch of each display driving unit is connected to a different green light constant current port of the constant current driving chip of the display driving unit, and the blue light driving terminal of each blue light display branch of each display driving unit is connected to a different blue light constant current port of the constant current driving chip of the display driving unit.

[0007] The constant current driver chip has a built-in main control module, a communication module, a display processing module, a video memory module, a first constant current control module, a second constant current control module, and a third constant current control module. The main control module is connected to the communication module, the display processing module, and the video memory module respectively. The communication module is used to communicate with the display controller. The first, second, and third constant current control modules are connected to the display processing module. The first constant current control module is connected to a first current setting resistor and leads out each red light constant current port of the constant current driver chip. The second constant current control module is connected to a second current setting resistor and leads out each green light constant current port of the constant current driver chip. The third constant current control module is connected to a third current setting resistor and leads out each blue light constant current port of the constant current driver chip.

[0008] The first constant current control module of the constant current driver chip leads out each red light constant current port of the constant current driver chip through the first blanking module; the second constant current control module of the constant current driver chip leads out each green light constant current port of the constant current driver chip through the second blanking module; and the third constant current control module of the constant current driver chip leads out each blue light constant current port of the constant current driver chip through the third blanking module. The main control module is connected to the first blanking module, the second blanking module, and the third blanking module through the blanking control module.

[0009] The communication module of the constant current driver chip leads out the data input port, data output port, latch port, clock port, and enable port of the constant current driver chip; the latch port, clock port, and enable port of the constant current driver chip of each display driver unit are respectively connected to the display controller; the data input port of the constant current driver chip of the first display driver unit is connected to the display controller; the data output port of the constant current driver chip of the first display driver unit is connected to the data input port of the constant current driver chip of the second display driver unit, and so on, until the data output port of the constant current driver chip of the second-to-last display driver unit is connected to the data input port of the constant current driver chip of the last display driver unit.

[0010] The switching transistor is a MOSFET.

[0011] After adopting the above solution, each red light display branch, each blue light display branch, and each green light display branch of each display driving unit of the present invention is supplied with current through a constant current driving chip of the display driving unit. In this way, the power consumption of the constant current driving chips of each display driving unit is similar, and the heat generation of the constant current driving chips of each display driving unit is the same. This avoids the phenomenon that some constant current driving chips in existing full-color displays are prone to overheating during operation, and solves the problem of uneven display color caused by local overheating in existing full-color LED displays. Attached Figure Description

[0012] Figure 1 is a circuit schematic diagram of the present invention.

[0013] Figure 2 is a schematic block diagram of the constant current drive chip of the present invention.

[0014] Label Explanation:

[0015] Display controller 1,

[0016] Line control module 2, switch K,

[0017] Display driver unit 3

[0018] Red light display branch 31, red LED lamp bead DR.

[0019] Green light display branch 32, green LED beads DG,

[0020] Blue light display branch 33, blue LED lamp beads DB,

[0021] Constant current driver chip 34,

[0022] Main control module 341,

[0023] Communication module 342,

[0024] Display processing module 343,

[0025] Memory module 344,

[0026] First constant current control module 345, first blanking module 3451, first current setting resistor 3452.

[0027] Second constant current control module 346, second blanking module 3461, second current setting resistor 3462

[0028] The third constant current control module 347, the third blanking module 3471, and the third current setting resistor 3472 are all included.

[0029] Blanking control module 348,

[0030] Red light constant current port Rout, green light constant current port Gout, blue light constant current port Bout.

[0031] Data input port SDI, data output port SDO, latch port LATCH, clock port SCLK, enable port OE.

[0032] Drive power supply 4. Embodiments of the present invention

[0033] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0034] As shown in Figures 1 and 2, this invention discloses a full-color LED display screen driving circuit, which includes a display controller 1, a row control module 2, and at least two display driving units 3; the row control module 2 includes multiple switching transistors K, the input of each switching transistor K is connected to a driving power supply 4, and the control terminal of each switching transistor K is connected to the display controller 1; the display driving unit 3 includes at least one red light display branch 31, at least one green light display branch 32, at least one blue light display branch 33, and a constant current driving chip 34; each red light display branch 31 includes multiple red... Each red light display branch 31 includes multiple green LEDs 321. The anodes of each red LED DR in each red light display branch 31 are connected to the output terminals of each switching transistor K in the horizontal control module 2, and the cathodes of each red LED DR in each red light display branch 31 are connected to the red light driving terminal of that red light display branch 31. The cathode of each blue light display branch 32 is connected to the green light driving terminal of the green light display branch 32; each blue light display branch 33 includes multiple blue LED beads DB, the anode of each blue LED bead DB in each blue light display branch 33 is connected to the output terminal of each switching transistor K in the horizontal control module 2, and the cathode of each blue LED bead DB in each blue light display branch 33 is connected to the blue light driving terminal of the blue light display branch 33; the constant current driving chip 34 is connected to the display controller 1, and the constant current driving chip 34 has at least one red light constant current port Rout, at least one green light constant current port Gout, and at least A blue light constant current port Bout; the red light driving terminals of each red light display branch 31 of each display driving unit 3 are respectively connected to different red light constant current ports Rout of the constant current driving chip 34 of the display driving unit 3; the green light driving terminals of each green light display branch 32 of each display driving unit 3 are respectively connected to different green light constant current ports Gout of the constant current driving chip 34 of the display driving unit 3; and the blue light driving terminals of each blue light display branch 33 of each display driving unit 3 are respectively connected to different blue light constant current ports Bout of the constant current driving chip 34 of the display driving unit 3.

[0035] In this invention, each of the red light display branches 31, blue light display branches 33, and green light display branches 32 of each display driving unit 3 is supplied with current through a constant current driving chip 34 of the display driving unit 3. In this way, the power consumption of the constant current driving chips 34 of each display driving unit 3 is similar, and the heat generation of the constant current driving chips 34 of each display driving unit 3 is the same. This avoids the phenomenon that some constant current driving chips 34 in existing full-color displays are prone to overheating during operation, and solves the problem of uneven display color caused by local overheating in existing full-color LED displays.

[0036] In an embodiment of the present invention, the constant current driving chip 34 integrates a main control module 341, a communication module 342, a display processing module 343, a video memory module 344, a first constant current control module 345, a second constant current control module 346, and a third constant current control module 347. The main control module 341 is connected to the communication module 342, the display processing module 343, and the video memory module 344 respectively. The communication module 342 is used to communicate with the display controller 1. The first constant current control module 345, the second constant current control module 346, and the third constant current control module 347 are connected to the display controller 1 respectively. The processing module 343 is connected to the first constant current control module 345, which is connected to the first current setting resistor 3452. The first constant current control module 345 leads out each red light constant current port Rout of the constant current drive chip 34. The second constant current control module 346 is connected to the second current setting resistor 3462, which leads out each green light constant current port Gout of the constant current drive chip 34. The third constant current control module 347 is connected to the third current setting resistor 3472, which leads out each blue light constant current port Bout of the constant current drive chip 34. The first current setting resistor 3452 is used to set the output current of each red light constant current port Rout, the second current setting resistor 3462 is used to set the output current of each green light constant current port Gout, and the third current setting resistor 3472 is used to set the output current of each blue light constant current port Bout. The first current setting resistor 3452, the second current setting resistor 3462 and the third current setting resistor 3472 can be built into the constant current driver chip 34 or set outside the constant current driver chip 34. Furthermore, in this invention, each red light constant current port Rout of the constant current driver chip 34 is led out by the first constant current control module 345, each green light constant current port Gout of the constant current driver chip 34 is led out by the second constant current control module 346, and each blue light constant current port Bout of the constant current driver chip 34 is led out by the third constant current control module 347. The first constant current control module 345, the second constant current control module 346, and the third constant current control module 347 are independent of each other, which can avoid the problem of mutual interference between the red light constant current port Rout, the green light constant current port Gout, and the blue light constant current port Bout.

[0037] In an embodiment of the present invention, the first constant current control module 345 leads out each red light constant current port Rout of the constant current driver chip 34 through the first blanking module 3451; the second constant current control module 346 leads out each green light constant current port Gout of the constant current driver chip 34 through the second blanking module 3461; and the third constant current control module 347 leads out each blue light constant current port Bout of the constant current driver chip 34 through the third blanking module 3471. The main control module 341 is connected through the blanking control module 8. The first blanking module 3451, the second blanking module 3461, and the third blanking module 3471 control the first blanking module 3451, the second blanking module 3461, and the third blanking module 3471 to prevent the "ghosting" problem from appearing on the full-color LED display. The first blanking module 3451, the second blanking module 3461, the third blanking module 3471, and the blanking control module 8 are common circuits.

[0038] In an embodiment of the present invention, the constant current driver chip 34 communication module 342 communicates with the display controller 1 via the SDI protocol. The constant current driver chip 34 communication module 342 leads out the constant current driver chip 34's data input port SDI, data output port SDO, latch port LATCH, clock port SCLK, and enable port OE. The latch port LATCH, clock port SCLK, and enable port OE of the constant current driver chip 34 of each display driver unit 3 are respectively connected to the display controller 1. The data input port SDI of the constant current driver chip 34 of the first display driver unit 3 is connected to the display controller 1. The data output port SDO of the constant current driver chip 34 of the first display driver unit 3 is connected to the data input port SDI of the constant current driver chip 34 of the second display driver unit 3, and so on, until the data output port SDO of the constant current driver chip 34 of the penultimate display driver unit 3 is connected to the data input port SDI of the constant current driver chip 34 of the penultimate display driver unit 3.

[0039] In an embodiment of the present invention, the switching transistor K is a MOS transistor, which has the advantage of fast response speed.

[0040] The above embodiments and figures are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A driving circuit for a full-color LED display screen, characterized in that: It includes a display controller, a row control module, and at least two display driver units; The row control module includes multiple switching transistors, the input of each switching transistor is connected to the drive power supply, and the control terminal of each switching transistor is connected to the display controller. The display driving unit includes at least one red light display branch, at least one green light display branch, at least one blue light display branch, and a constant current driving chip; Each red light display branch includes multiple red light LED beads. The anode of each red light LED bead in each red light display branch is connected to the output terminal of each switching transistor of the horizontal control module, and the cathode of each red light LED bead in each red light display branch is connected to the red light driving terminal of that red light display branch. Each green light display branch includes multiple green LED beads. The anode of each green LED bead in each green light display branch is connected to the output terminal of each switching transistor of the horizontal control module, and the cathode of each green LED bead in each green light display branch is connected to the green light driving terminal of that green light display branch. Each blue light display branch includes multiple blue LED beads. The anode of each blue LED bead in each blue light display branch is connected to the output terminal of each switching transistor of the horizontal control module, and the cathode of each blue LED bead in each blue light display branch is connected to the blue light driving terminal of that blue light display branch. The constant current driver chip is connected to the display controller, and the constant current driver chip has at least one red light constant current port, at least one green light constant current port and at least one blue light constant current port; The red light driving terminals of each red light display branch of each display driving unit are respectively connected to different red light constant current ports of the constant current driving chip of the display driving unit. The green light driving terminals of each green light display branch of each display driving unit are respectively connected to different green light constant current ports of the constant current driving chip of the display driving unit. The blue light driving terminals of each blue light display branch of each display driving unit are respectively connected to different blue light constant current ports of the constant current driving chip of the display driving unit.

2. The full-color LED display screen driving circuit as described in claim 1, characterized in that: The constant current driver chip has a built-in main control module, communication module, display processing module, video memory module, first constant current control module, second constant current control module and third constant current control module; The main control module is connected to the communication module, display processing module, and video memory module respectively. The communication module is used to communicate with the display controller. The first constant current control module, the second constant current control module, and the third constant current control module are respectively connected to the display processing module. The first constant current control module is connected to a first current setting resistor and leads out each red light constant current port of the constant current driver chip. The second constant current control module is connected to a second current setting resistor and leads out each green light constant current port of the constant current driver chip. The third constant current control module is connected to a third current setting resistor and leads out each blue light constant current port of the constant current driver chip.

3. The full-color LED display driving circuit as described in claim 2, characterized in that: The first constant current control module of the constant current driver chip leads out each red light constant current port of the constant current driver chip through the first blanking module; the second constant current control module of the constant current driver chip leads out each green light constant current port of the constant current driver chip through the second blanking module; and the third constant current control module of the constant current driver chip leads out each blue light constant current port of the constant current driver chip through the third blanking module. The main control module is connected to the first blanking module, the second blanking module, and the third blanking module through the blanking control module.

4. The full-color LED display driving circuit as described in claim 2, characterized in that: The communication module of the constant current driver chip provides access to the data input port, data output port, latch port, clock port, and enable port of the constant current driver chip. The latch port, clock port, and enable port of the constant current driver chip in each display driver unit are connected to the display controller; the data input port of the constant current driver chip in the first display driver unit is connected to the display controller. The data output port of the constant current driver chip of the first display driver unit in each display driver unit is connected to the data input port of the constant current driver chip of the second display driver unit, and so on, until the data output port of the constant current driver chip of the second to last display driver unit is connected to the data input port of the constant current driver chip of the last display driver unit.

5. The full-color LED display driving circuit as described in claim 1, characterized in that: The switching transistor is a MOSFET.

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