Driving circuit of display panel, driving method of display panel and display device

Abstract

The invention discloses a driving circuit of a display panel, a driving method of the display panel and a display device, and mainly relates to the technical field of display, the output end of a control panel is connected with the input end of a booster circuit module, and the output end of the booster circuit is connected with the input end of a source electrode driving circuit module; the input end and the output end of the selective step-down circuit module are respectively connected between the output end of the control board and the input end of the boost circuit module, or the input end and the output end of the selective step-down circuit module are respectively connected between the output end of the boost circuit module and the input end of the source electrode driving circuit module; the selection step-down circuit module is used for reducing the standard voltage signal higher than or equal to the threshold voltage and output by the control panel to be lower than the threshold voltage and then outputting the standard voltage signal, and meanwhile directly outputting the standard voltage signal lower than the threshold voltage and output by the control panel. Through the design, the source electrode driving circuit module is prevented from heating, the display fault problem is avoided, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a driving circuit of a display panel, a driving method of a display panel, and a display device. Background Art

[0002] Most of the display screens used in current display devices are liquid crystal display screens, which are composed of a liquid crystal panel and a backlight source. In order for the liquid crystal display screen to display normally, it is necessary to provide appropriate driving power to the liquid crystal panel and the backlight source respectively.

[0003] However, in the existing driving circuit of the display panel, there is a phenomenon that the source driving circuit module generates abnormal heat. Summary of the invention

[0004] The purpose of the present application is to provide a display panel driving circuit, a display panel driving method and a display device to prevent the source driving circuit module from heating up, avoid display failure problems and reduce costs.

[0005] The present application discloses a driving circuit of a display panel, the driving circuit of the display panel comprising a control board, a voltage-reduction circuit module, a voltage-boosting circuit module and a source driving circuit module;

[0006] The output end of the control board is connected to the input end of the boost circuit module, and the output end of the boost circuit is connected to the input end of the source drive circuit module;

[0007] The input end and the output end of the selective buck circuit module are respectively connected between the output end of the control board and the input end of the boost circuit module, or the input end and the output end of the selective buck circuit module are respectively connected between the output end of the boost circuit module and the input end of the source drive circuit module;

[0008] The selective step-down circuit module is used to reduce the standard voltage signal output by the control board that is greater than or equal to the threshold voltage to less than the threshold voltage before outputting it, and at the same time directly output the standard voltage signal output by the control board that is less than the threshold voltage.

[0009] Optionally, the input end of the selective buck circuit module is connected to the output end of the control board to receive the standard voltage signal output by the control board, and the output end of the selective buck circuit module is connected to the input end of the boost circuit module.

[0010] Optionally, the voltage reduction circuit module includes a selection control unit, a first control switch, a second control switch and a voltage reduction control unit;

[0011] The input end of the selection control unit is connected to the output end of the control board, and the output end of the selection control unit is connected to the control end of the first control switch and the control end of the second control unit;

[0012] The input end of the first control switch is connected to the output end of the control board, and the output end of the first control switch is connected to the input end of the boost circuit module;

[0013] The input end of the second control switch is connected to the output end of the control board, the output end of the second control switch is connected to the input end of the step-down control unit, and the output end of the step-down control unit is connected to the input end of the boost circuit module;

[0014] The selection control unit is used to select and control one of the first control switch and the second control switch to be turned on and the other to be turned off according to the relationship between the input standard voltage signal and the threshold voltage; the step-down control unit is used to reduce the voltage value of the input signal that is greater than or equal to the threshold voltage.

[0015] Optionally, the selection control unit includes a voltage stabilizing diode, a first resistor, a second resistor, a first N-type transistor, and a second N-type transistor;

[0016] The cathode of the voltage zener diode is connected to the output end of the control board, the anode of the voltage zener diode is connected to the control end of the first N-type transistor, one end of the first resistor is connected to the output end of the control board, and the other end is connected to the input end of the first N-type transistor, and the output end of the first N-type transistor is grounded;

[0017] The control end of the second N-type transistor is connected between the first resistor and the input end of the first N-type transistor, one end of the second resistor is connected to the output end of the control board, and the other end is connected to the input end of the second N-type transistor, and the output end of the second N-type transistor is grounded;

[0018] The first control switch comprises a first P-type transistor;

[0019] The control end of the first P-type transistor is connected between the second resistor and the input end of the second N-type transistor, the input end of the first P-type transistor is connected to the output end of the control board, and the output end of the first P-type transistor is connected to the input end of the boost circuit module;

[0020] The second control switch includes a second P-type transistor;

[0021] The control end of the second P-type transistor is connected to the first resistor and the input end of the first N-type transistor, and the input end of the second P-type transistor is connected to the output end of the control board;

[0022] The voltage reduction control unit includes a voltage dividing resistor;

[0023] Two ends of the voltage-dividing resistor are respectively connected to the output end of the second P-type transistor and the input end of the boost circuit module.

[0024] Optionally, the selection control unit includes a voltage stabilizing diode, a first resistor, a second resistor, a first N-type transistor, and a second N-type transistor;

[0025] The cathode of the voltage zener diode is connected to the output end of the control board, the anode of the voltage zener diode is connected to the control end of the first N-type transistor, one end of the first resistor is connected to the output end of the control board, and the other end is connected to the input end of the first N-type transistor, and the output end of the first N-type transistor is grounded;

[0026] The control end of the second N-type transistor is connected between the first resistor and the input end of the first N-type transistor, one end of the second resistor is connected to the output end of the control board, and the other end is connected to the input end of the second N-type transistor, and the output end of the second N-type transistor is grounded;

[0027] The first control switch comprises a first P-type transistor;

[0028] The control end of the first P-type transistor is connected between the second resistor and the input end of the second N-type transistor, the input end of the first P-type transistor is connected to the output end of the control board, and the output end of the first P-type transistor is connected to the input end of the boost circuit module;

[0029] The second control switch includes a second P-type transistor;

[0030] The control end of the second P-type transistor is connected to the first resistor and the input end of the first N-type transistor, and the input end of the second P-type transistor is connected to the output end of the control board;

[0031] The step-down control unit includes a first transistor;

[0032] The input end of the first transistor is connected to the output end of the second P-type transistor, and the output end of the first transistor is connected to the output end of the control board;

[0033] The control terminal of the first transistor is used to receive a control signal to adjust the on-resistance of the first transistor.

[0034] Optionally, the driving circuit of the display panel further includes a first voltage adjustment module, a second voltage adjustment module, a first buck conversion circuit, a second buck conversion circuit and a gate driving circuit module;

[0035] The input end of the first voltage adjustment module is connected to the input end of the control board, and the output end of the first voltage adjustment module is connected to the input end of the gate drive circuit module;

[0036] The input end of the second voltage adjustment module is connected to the input end of the control board, and the output end of the second voltage adjustment module is connected to the input end of the gate drive circuit module;

[0037] The input end of the first buck conversion circuit is connected to the input end of the control board, and the output end of the first buck conversion circuit is connected to the input end of the source drive circuit module;

[0038] The input end of the second buck conversion circuit is connected to the input end of the control board, and the output end of the second buck conversion circuit is connected to the input end of the source drive circuit module;

[0039] The selective buck circuit module is connected only between the control board and the boost circuit module, or the selective buck circuit module is connected only between the boost circuit module and the source driving circuit module;

[0040] The first voltage adjustment module is used to generate a VGH signal; the second voltage adjustment module is used to generate a VGL signal; the first step-down conversion circuit is used to generate a Vlogic signal; the second step-down conversion circuit is used to generate a Vcore signal; the selection step-down circuit module and the boost circuit module are used together to generate a VAA voltage.

[0041] Optionally, the output voltage of the control board is 12V, the breakdown voltage of the voltage regulator diode is 12V, and the resistance value of the step-down control unit is set to 5 ohms.

[0042] The present application also discloses a display panel driving method, the display panel driving method is used to drive a driving circuit of the display panel, and the display panel driving method comprises the steps of:

[0043] The control board outputs a standard voltage signal;

[0044] The step-down circuit module receives the standard voltage signal, and when the standard voltage signal is higher than or equal to a threshold voltage, controls the voltage value of the standard voltage signal to be reduced to less than the threshold voltage and then outputs it to the boost circuit module; when the standard voltage signal is less than the threshold voltage, directly outputs the standard voltage signal to the boost circuit module;

[0045] The boost circuit module receives the voltage signal output by the selected buck circuit module, and boosts the voltage signal output by the selected buck circuit module to a VAA voltage, and outputs the voltage to the source drive circuit module.

[0046] Optionally, the voltage reduction circuit module includes a selection control unit, a first control switch, a second control switch and a voltage reduction control unit;

[0047] The step of selecting the step-down circuit module to receive the standard voltage signal, and when the standard voltage signal is higher than or equal to a threshold voltage, controlling the voltage value of the standard voltage signal to be reduced to less than the threshold voltage and then outputting it to the boost circuit module; and when the standard voltage signal is less than the threshold voltage, directly outputting the standard voltage signal to the boost circuit module comprises:

[0048] The selection control unit receives the standard voltage signal;

[0049] When the standard voltage signal is lower than the threshold voltage, the first control switch is controlled to be turned on and the second control switch is controlled to be turned off, and the standard voltage signal is directly output to the boost circuit module through the first control switch;

[0050] When the standard voltage signal is higher than or equal to the threshold voltage, the first control switch is controlled to be closed and the second control switch is controlled to be opened, and the standard voltage signal is output to the step-down control unit through the second control switch. The step-down control unit reduces the standard voltage signal to a level less than or equal to the threshold signal and then outputs it to the boost circuit module.

[0051] The present application also discloses a display device, which includes a display panel and a driving circuit of the display panel. The driving circuit of the display panel is connected to the display panel to provide a driving signal for the display panel.

[0052] Compared with the existing display panel driving circuit solutions, the present application adds a step-down circuit module to step down the voltage entering the source driving circuit module, thereby ensuring that the difference between the voltage input to the source driving circuit module and the output voltage of the source driving circuit module is reduced, thereby avoiding the problem of heat loss in the transistor inside the source driving voltage, preventing the source driving circuit module from heating up and avoiding display failure problems; and since there is no need to attach a heat sink to the source driving circuit module, the method of the present application can also reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0054] Figure 1 is a schematic diagram of a display device according to an embodiment of the present application;

[0055] Figure 2 is a schematic diagram of a driving circuit of a display panel according to the first embodiment of the present application;

[0056] Figure 3 is a schematic diagram of a source driving circuit module of the first embodiment of the present application;

[0057] Figure 4 is a modular schematic diagram of a source driving circuit module of the first embodiment of the present application;

[0058] Figure 5 is a schematic diagram of a source driving circuit module of the first embodiment of the present application;

[0059] Fig. 6A is a schematic diagram of a simulation waveform diagram of the first embodiment of the present application;

[0060] Figure 6B is a schematic diagram of a simulation waveform diagram of the first embodiment of the present application;

[0061] Figure 6C is a schematic diagram of a simulation waveform diagram of the first embodiment of the present application;

[0062] Figure 7 is a schematic diagram of a driving circuit of a display panel according to a second embodiment of the present application;

[0063] Figure 8 is a modular schematic diagram of a source driving circuit module of the second embodiment of the present application;

[0064] Fig. 9 is a schematic diagram of a source driving circuit module of the second embodiment of the present application;

[0065] Fig.10 is a schematic diagram of a source driving circuit module of the third embodiment of the present application;

[0066] Fig.11 It is a schematic diagram of a method for driving a display panel according to an embodiment of the present application.

[0067] Among them, 10, display device; 20, display panel; 30, display panel drive circuit; 100, control board; 200, select step-down circuit module; 210, select control unit; 211, voltage regulator diode; 212, first resistor; 213, second resistor; 214, first N-type transistor; 215, second N-type transistor; 216, third resistor; 220, first control switch; 221, first P-type transistor; 230, second control switch; 231, second P-type transistor; 240, step-down control unit; 241, voltage dividing resistor; 242, first transistor; 243, control end 243 of first transistor; 250, boost voltage-converting circuit module; 261, a fourth resistor; 262, a fifth resistor; 271, selecting the input end of the voltage-converting circuit module; 272, selecting the output end of the voltage-converting circuit module; 300, a source driving circuit module; 310, a source driving output circuit; 311, a power supply input end; 312, a digital-to-analog voltage signal input end; 313, a first transistor; 314, a second transistor; 315, a data signal output end; 400, a first voltage adjustment module; 500, a second voltage adjustment module; 600, a first step-down conversion circuit; 700, a second step-down conversion circuit; 800, a gate driving circuit module; 900, a PWM control chip. DETAILED DESCRIPTION

[0068] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative, but the present application can be implemented in many alternative forms and should not be construed as being limited to only the embodiments described herein.

[0069] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; "plurality" means two or more. The term "including" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may exist or be added.

[0070] In addition, terms indicating orientation or positional relationships, such as “center,” “lateral,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inside,” and “outside,” are described based on the orientation or relative positional relationships shown in the accompanying drawings and are merely simplified descriptions for the convenience of describing the present application. They do not indicate that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limitations on the present application.

[0071] In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0072] The present application is described in detail below with reference to the accompanying drawings and optional embodiments.

[0073] Figure 1 is a schematic diagram of a display device according to an embodiment of the present application. Figure 1 As shown, the present application discloses a display device 10 , which includes a display panel 20 and a driving circuit 30 of the display panel. The driving circuit 30 of the display panel is connected to the display panel 20 to provide a driving signal for the display panel 20 .

[0074] The present application also discloses a display panel driving circuit 30, which can be used in the display device 10 described above. For the display panel driving circuit 30, the present application provides the following design, which is specifically introduced through several embodiments:

[0075] Embodiment 1:

[0076] Figure 2 is a schematic diagram of a driving circuit of a display panel according to the first embodiment of the present application, such as Figure 2 As shown, the present application discloses a driving circuit 30 for a display panel, and the driving circuit 30 for the display panel includes a control board 100 , a voltage-reduction circuit module 200 , a voltage-reduction circuit module 250 , and a source driving circuit module 300 .

[0077] The output end of the control board 100 is connected to the input end of the boost circuit module 250 , and the output end of the boost circuit is connected to the input end of the source driving circuit module 300 .

[0078] The input end 271 and the output end 272 of the selective buck circuit module are respectively connected between the output end of the control board 100 and the input end of the boost circuit module 250, or the input end 271 and the output end 272 of the selective buck circuit module are respectively connected between the output end of the boost circuit module 250 and the input end of the source drive circuit module 300.

[0079] This embodiment is explained by taking the example that the input end 271 and the output end 272 of the voltage-reducing circuit module are respectively connected between the output end of the control board 100 and the input end of the voltage-reducing circuit module 250 .

[0080] The selective step-down circuit module 200 is used to reduce the standard voltage signal output by the control board 100 that is greater than or equal to the threshold voltage to less than the threshold voltage before outputting it, and directly output the standard voltage signal output by the control board 100 that is less than the threshold voltage.

[0081] Among them, the existing general control board 100 is used to output a standard voltage signal, the boost circuit module 250 is a BOOST boost circuit, which is used to generate a VAA voltage (analog power supply voltage), and the source drive circuit module 300 generates a data signal according to the VAA voltage and outputs it to the display panel 20, and the data signal is used to control the deflection of the liquid crystal in the display panel 20.

[0082] Figure 3 is a schematic diagram of a source driving circuit module of the first embodiment of the present application, combined with Figure 2-Figure 3 As shown, the source driving circuit module 300 includes multiple source driving output circuits 310, and the source driving output circuit 310 includes a power supply input terminal 311, a digital-to-analog voltage signal input terminal 312, a first transistor 313, a second transistor 314 and a data signal output terminal 315.

[0083] The digital-to-analog voltage signal input terminal 312 is connected to the control terminal of the first transistor and also to the control terminal of the second transistor 314. The input terminal of the first transistor 313 is connected to the power supply input terminal 311. In this embodiment, the input terminal of the first transistor 313 is connected to the output terminal of the boost circuit module 250.

[0084] In another embodiment, when the selective buck circuit module 200 is disposed between the boost circuit module 250 and the source driving circuit module 300 , the input end of the first transistor 313 is connected to the output end 272 of the selective buck circuit module.

[0085] The output end of the first transistor 313 is connected to the data signal output end 315 , the input end of the second transistor 314 is grounded, and the output end of the second transistor 314 is connected to the output end of the first transistor 313 .

[0086] Exemplarily, the first transistor 313 may be an NPN transistor, and the second transistor 314 may be a PNP transistor.

[0087] The digital-to-analog voltage signal input terminal 312 inputs a digital-to-analog voltage signal, and the data signal output terminal 315 outputs a data voltage to the display panel 20 for charging the pixel electrode and controlling the liquid crystal deflection.

[0088] The voltage coming from the digital-to-analog voltage signal input terminal 312 controls the conduction degree of the first transistor 313 and the second transistor 314, so that the voltage of the data signal output from the data signal output terminal 315 is the same as the voltage of the digital-to-analog voltage signal input from the digital-to-analog voltage signal input terminal 312.

[0089] In simple terms, the first transistor 313 and the second transistor 314 can be considered as variable resistors that change with the voltage of the digital-to-analog voltage signal. Under the voltage division of the first transistor 313 and the second transistor 314, the voltage of the data signal required by the display panel 20 is obtained.

[0090] The applicant has found that when the display device 10 is working, a large amount of heat will be generated on the source driving circuit module 300, and the source driving circuit module 300 is generally located next to the plastic frame of the display panel 20. If effective heat dissipation is not performed, when the local temperature is too high, the display panel 20 may be damaged, and there may even be safety risks. Therefore, a heat dissipation paste is previously attached to the source driving circuit module 300, but the heat dissipation paste will increase the cost.

[0091] The applicant found that the main reason for the heat generation on the source driver circuit module 300 is that the VAA voltage output by the existing display panel driver circuit fluctuates, which will output a larger voltage, while the data signal required to drive the liquid crystal deflection in the display panel 20 is lower, as follows.

[0092] The standard voltage signal generated by the control board 100 is 12V, and the current boost circuit module 250 adopts a BOOST boost circuit, whose main principle is to control the boost of the standard voltage signal through the PWM signal generated by the PWM control chip 900. However, due to the limitation of the PWM control chip 900, the standard voltage signal generated by the control board 100 is 12V. The voltage obtained after the boost circuit module 250 is boosted can only be about 1.14 times the standard voltage signal 12V, that is, the ideal VAA voltage is 13.68V, and the standard voltage signal has a fluctuation of ±10%, so the actual standard voltage signal ranges from 10.8 to 13.2V, so the actual VAA voltage value range is 12.312 to 15.048V.

[0093] Nowadays, as low-voltage liquid crystals are used more and more widely, even if the voltage for liquid crystal deflection can be made lower and lower, the data signal of the commonly used low-voltage liquid crystals can be reduced to below 13V, and even 11V can achieve deflection. Therefore, the ideal VAA voltage output by the existing boost circuit module 250 has a voltage value range of 12.312 to 15.048V, which will cause the heat loss of the first transistor 313 and the second transistor 314 to increase, thereby causing the heating problem of the source drive circuit module 300.

[0094] The voltage range value of the threshold voltage of the present application is less than or equal to the ideal VAA voltage / 1.14.

[0095] The present application reduces the voltage entering the source driver circuit module 300 by adding a selective step-down circuit module 200, thereby ensuring that the difference between the voltage input to the source driver circuit module 300 and the output voltage of the source driver circuit module 300 is reduced, thereby avoiding heat loss in the transistor inside the source driver circuit module 300, thereby preventing the source driver circuit module 300 from heating up and avoiding display failure problems; and there is no need to attach a heat sink to the source driver circuit module 300, which can also reduce costs.

[0096] Furthermore, there is no need to improve the control panel 100 , and the solution of the present application has a wider scope of application.

[0097] The driving circuit 30 of the display panel of the present application further includes a first voltage adjustment module 400 , a second voltage adjustment module 500 , a first buck conversion circuit 600 , a second buck conversion circuit 700 and a gate driving circuit module 800 .

[0098] Exemplarily, the first voltage adjustment module 400 includes a BOOST circuit or a Charge Pump circuit; the second voltage adjustment module 500 includes a BUCK-BOOST circuit (buck-boost converter) or a Charge Pump circuit; the first buck-type change circuit includes a BUCK circuit; the second buck-type conversion circuit 700 includes a BUCK circuit; and the gate drive circuit module 800 is a GDL circuit (Gate Driver less).

[0099] An input end of the first voltage adjustment module 400 is connected to an input end of the control board 100 , and an output end of the first voltage adjustment module 400 is connected to an input end of the gate driving circuit module 800 .

[0100] An input end of the second voltage adjustment module 500 is connected to an input end of the control board 100 , and an output end of the second voltage adjustment module 500 is connected to an input end of the gate driving circuit module 800 .

[0101] The input end of the first buck conversion circuit 600 is connected to the input end of the control board 100 , and the output end of the first buck conversion circuit 600 is connected to the input end of the source driving circuit module 300 .

[0102] The input end of the second buck conversion circuit 700 is connected to the input end of the control board 100 , and the output end of the second buck conversion circuit 700 is connected to the input end of the source driving circuit module 300 .

[0103] The first voltage adjustment module 400 is used to generate a VGH signal; the VGH signal is used to control the brightness and grayscale of the display panel 20; the VGH signal is usually a positive voltage. The second voltage adjustment module 500 is used to generate a VGL signal; the VG1 signal is used to control the refresh and switching of the liquid crystal display; the VGL signal is usually a negative voltage.

[0104] The first step-down conversion circuit 600 is used to generate a Vlogic signal (logic voltage signal), and the Vlogic signal is used to control the logic on and off of the internal digital circuit of the source driver circuit module 300 and the high and low levels of the external interface; the second step-down conversion circuit is used to generate a Vcore signal (core voltage signal), and the Vcore signal is also used to control the logic on and off of the internal digital circuit of the source driver circuit module 300; the selection step-down circuit module 200 and the boost circuit module 250 are jointly used to generate the VAA voltage.

[0105] The present application connects the selective buck circuit module 200 only between the control board 100 and the boost circuit module 250, or connects the selective buck circuit module 200 only between the boost circuit module 250 and the source driver circuit module 300; that is, the present application only steps down the VAA voltage that needs to be transmitted into the display panel 20, thereby ensuring that the added selective buck circuit module 200 will not affect the voltages of other circuit modules, thereby avoiding display abnormalities.

[0106] The input end 271 of the selective buck circuit module is connected to the output end of the control board 100 for receiving the standard voltage signal output by the control board 100 , and the output end 272 of the selective buck circuit module is connected to the input end of the boost circuit module 250 .

[0107] Compared with the solution of setting the selective buck circuit module 200 between the boost circuit board and the source driver circuit module 300, the VAA voltage output by the boost circuit module 250 is more stable and has less fluctuation than the VAA voltage output by the selective buck circuit module 200.

[0108] Figure 4 is a modular schematic diagram of a source driving circuit module of the first embodiment of the present application, such as Figure 4 As shown, the selective buck circuit module 200 includes a selective control unit 210, a first control switch 220, a second control switch 230 and a buck control unit 240, the input end of the selective control unit 210 is connected to the output end of the control board 100, and the output end of the selective control unit 210 is connected to the control end of the first control switch 220 and the control end of the second control unit.

[0109] The input end of the first control switch 220 is connected to the output end of the control board 100 , and the output end of the first control switch 220 is connected to the input end of the boost circuit module 250 .

[0110] The input end of the second control switch 230 is connected to the output end of the control board 100 , the output end of the second control switch is connected to the input end of the buck control unit 240 , and the output end of the buck control unit 240 is connected to the input end of the boost circuit module 250 .

[0111] The selection control unit 210 is used to select and control one of the first control switch 220 and the second control switch 230 to be turned on and the other to be turned off according to the relationship between the input standard voltage signal and the threshold voltage; the voltage reduction control unit 240 is used to reduce the voltage value of the input signal that is greater than or equal to the threshold voltage.

[0112] When the selection control unit 210 detects that the input standard voltage signal is greater than or equal to the threshold voltage, the first control switch 220 is controlled to be closed and the second control switch 230 is controlled to be opened. The input standard voltage signal will be output to the source driver circuit module 300 along the second control switch 230 and through the step-down control unit 240. After the voltage division effect of the step-down control unit 240, the output standard voltage signal can be reduced to less than the threshold voltage.

[0113] When the selection control unit 210 detects that the input standard voltage signal is less than the threshold voltage, the first control switch 220 is controlled to be turned on and the second control switch 230 is controlled to be turned off, and the input standard voltage signal is directly output to the source driving circuit module 300 along the first control switch 220 .

[0114] Figure 5is a schematic diagram of a source driving circuit module of the first embodiment of the present application, such as Figure 5 As shown, specifically, the selection control unit 210 includes a voltage stabilizing diode 211 , a first resistor 212 , a second resistor 213 , a first N-type transistor 214 , and a second N-type transistor 215 .

[0115] The cathode of the voltage-stabilizing diode 211 is connected to the output end of the control board 100, the anode of the voltage-stabilizing diode 211 is connected to the control end of the first N-type transistor 214, one end of the first resistor 212 is connected to the output end of the control board 100, and the other end is connected to the input end of the first N-type transistor 214, and the output end of the first N-type transistor 214 is grounded; the first N-type transistor 214 is an NMOS transistor, which is disconnected when the level is low and turned on when the level is high.

[0116] The control end of the second N-type transistor 215 is connected between the first resistor 212 and the input end of the first N-type transistor 214, one end of the second resistor 213 is connected to the output end of the control board 100, and the other end is connected to the input end of the second N-type transistor 215, and the output end of the second N-type transistor 215 is grounded; the second N-type transistor 215 is an NMOS transistor, and the second N-type transistor 215 is disconnected when the level is low, and the second N-type transistor 215 is turned on when the level is high.

[0117] The first control switch 220 includes a first P-type transistor 221 ; the first P-type transistor 221 is a PMOS transistor. When the voltage level is low, the first P-type transistor 221 is turned on, and when the voltage level is high, the first P-type transistor 221 is turned off.

[0118] The control end of the first P-type transistor 221 is connected between the second resistor 213 and the input end of the second N-type transistor 215, the input end of the first P-type transistor 221 is connected to the output end of the control board 100, and the output end of the first P-type transistor 221 is connected to the input end of the boost circuit module 250.

[0119] The second control switch 230 includes a second P-type transistor 231 ; the second P-type transistor 231 is a PMOS transistor. When the voltage level is low, the second P-type transistor 231 is turned on, and when the voltage level is high, the second P-type transistor 231 is turned off.

[0120] The control end of the second P-type transistor 231 is connected to the first resistor 212 and the input end of the first N-type transistor 214 , and the input end of the second P-type transistor 231 is connected to the output end of the control board 100 .

[0121] The voltage-reducing control unit 240 includes a voltage-dividing resistor 241 ; the voltage-dividing resistor 241 performs voltage-dividing processing on the standard voltage signal; and two ends of the voltage-dividing resistor 241 are respectively connected to the output end of the second P-type transistor 231 and the input end of the boost circuit module 250 .

[0122] The function of the Zener diode 211 is to prevent a current greater than or equal to a threshold voltage from being directly output from the first P-type transistor 221 . Exemplarily, the breakdown voltage of the Zener diode 211 is equal to the threshold voltage.

[0123] Furthermore, the selection control unit 210 may also include a third resistor 216, and the selection buck circuit module 200 may also include a fourth resistor 261 and a fifth resistor 262, one end of the third resistor 216 is connected to the positive electrode of the voltage-regulating diode 211, and the other end is grounded, and the control end of the first N-type transistor 214 is connected between the third resistor 216 and the positive electrode of the voltage-regulating diode 211; the two ends of the fourth resistor 261 are respectively connected between the input end and the control end of the first control switch 220; and the two ends of the fifth resistor 262 are respectively connected between the input end and the control end of the second control switch 230.

[0124] The third resistor 216 is used for generating a voltage at Va when the voltage stabilizing diode 211 is reversely broken down and turned on, and the current flows through the third resistor 216. When the voltage at Va is greater than the turn-on voltage of the first N-type transistor 214, the first N-type transistor 214 is turned on. The fourth resistor 261 is used to prevent the first P-type transistor 221 from being mis-turned on; the fifth resistor 262 is used to prevent the second P-type transistor 231 from being mis-turned on.

[0125] A voltage zener diode 211 with a breakdown voltage less than or equal to the ideal VAA voltage / 1.14 is selected as the voltage zener diode of the present application.

[0126] When the voltage entering from the input terminal 271 of the selected buck circuit module is greater than or equal to the breakdown voltage of the Zener diode 211, the Zener diode 211 is broken down, the Va voltage is pulled up, the first N-type transistor 214 is turned on, the Vb voltage is equal to 0V, and the second N-type transistor 215 is turned off; the voltage at Vc is pulled up, the first P-type transistor 221 is turned off, and the second P-type transistor 231 is turned on, then the voltage entering from the input terminal 271 of the selected buck circuit module is output through the voltage divider resistor 241.

[0127] When the voltage entering from the input terminal 271 of the selected buck circuit module is less than the breakdown voltage of the Zener diode 211, the Zener diode 211 is not broken down, the voltage at Va is equal to 0V, the first N-type transistor 214 is turned off, the voltage at Vb is pulled up, the second N-type transistor 215 is turned on, the voltage at Vc is equal to 0V, the first P-type transistor 221 is turned on, and the second P-type transistor 231 is turned off, then the voltage entering from the input terminal 271 of the selected buck circuit module is directly output from the first P-type transistor 221.

[0128] Fig. 6A is a schematic diagram of a simulation waveform diagram of the first embodiment of the present application, Figure 6B is a schematic diagram of a simulation waveform diagram of the first embodiment of the present application, Figure 6C is a schematic diagram of a simulation waveform diagram of the first embodiment of the present application, such as Figure 6A-6C As shown, Fig. 6A The horizontal axis represents time, and the vertical axis represents voltage. Fig. 6A The solid line M1 in the figure represents the relationship between the voltage signal entering the input end of the step-down circuit module 200 and time, and the solid line M2 represents the relationship between the voltage signal output from the output end of the step-down circuit module 200 and time; Figure 6B is the relationship between the conduction current of the first control switch 220 and time, the abscissa represents time, and the ordinate represents current; Figure 6C : is the relationship between the conduction current of the second control switch 230 and time, the abscissa represents time, and the ordinate represents current.

[0129] Exemplarily, the output voltage of the control board 100 is 12V, the breakdown voltage of the voltage regulator diode 211 is 12V, and the resistance value of the step-down control unit 240 is set to 5 ohms.

[0130] This circuit is simulated, and the standard voltage signal is controlled to gradually increase from 10V to 15V, the breakdown voltage of the voltage regulator diode 211 is 12V, and the resistance value of the voltage reduction control unit 240 is set to 5 ohms. When the standard voltage signal increases to 12V, the voltage regulator diode 211 is broken down, and at the same time, the first control switch 220 is closed, and the second control switch 230 is opened, and the voltage signal entering from the input end of the voltage reduction circuit module 200 is reduced and only output from the output end of the voltage reduction circuit module 200.

[0131] Second embodiment:

[0132] Figure 7 is a schematic diagram of a driving circuit of a display panel according to a second embodiment of the present application, Figure 8 is a modular schematic diagram of a source driving circuit module of the second embodiment of the present application, Fig. 9is a schematic diagram of a source driving circuit module of the second embodiment of the present application, such as Figure 7-Figure 9 As shown, the difference from the first embodiment is that the step-down control unit 240 of this embodiment includes a controllable resistor. Specifically, the selection control unit 210 includes a voltage regulator diode 211, a first resistor 212, a second resistor 213, a first N-type transistor 214 and a second N-type transistor 215.

[0133] The cathode of the Zener diode 211 is connected to the output end of the control board 100, the anode of the Zener diode 211 is connected to the control end of the first N-type transistor 214, one end of the first resistor 212 is connected to the output end of the control board 100, and the other end is connected to the input end of the first N-type transistor 214, and the output end of the first N-type transistor 214 is grounded.

[0134] The control end of the second N-type transistor 215 is connected between the first resistor 212 and the input end of the first N-type transistor 214, one end of the second resistor 213 is connected to the output end of the control board 100, and the other end is connected to the input end of the second N-type transistor 215, and the output end of the second N-type transistor 215 is grounded.

[0135] The first control switch 220 includes a first P-type transistor 221; the control end of the first P-type transistor 221 is connected between the second resistor 213 and the input end of the second N-type transistor 215, the input end of the first P-type transistor 221 is connected to the output end of the control board 100, and the output end of the first P-type transistor 221 is connected to the input end of the boost circuit module 250.

[0136] The second control switch 230 includes a second P-type transistor 231 ; the control end of the second P-type transistor 231 is connected to the first resistor 212 and the input end of the first N-type transistor 214 , and the input end of the second P-type transistor 231 is connected to the output end of the control board 100 .

[0137] The step-down control unit 240 includes a first transistor 242 ; an input end of the first transistor 242 is connected to an output end of the second P-type transistor 231 , and an output end of the first transistor 242 is connected to an output end of the control board 100 .

[0138] The control terminal 243 of the first transistor is used to receive a control signal to adjust the on-resistance of the first transistor 242 .

[0139] The first transistor 242 includes an NMOS transistor or a PMOS transistor. The control terminal 243 of the first transistor can receive a signal generated by the PWM control chip 900 to change the on-resistance of the first transistor 242, so that the on-resistance of the first transistor 242 can be controlled by a program. That is, the drive circuit 30 of the display panel also includes a PWM control chip 900, and the PWM control chip 900 is connected to the control terminal 243 of the first transistor.

[0140] Compared with the design scheme of the step-down control unit 240 directly adopting the voltage divider resistor 241 in the first embodiment, the scheme of this embodiment can change the on-resistance of the first transistor 242 through the PWM control chip 900, so that the program control can be more flexible, and there is no need to replace the voltage divider resistor 241 when the output VAA voltage needs to be adjusted.

[0141] Embodiment 3:

[0142] Fig.10 is a schematic diagram of a source driving circuit module of the third embodiment of the present application, such as Fig.10 As shown, different from the first embodiment, the input terminal 271 and the output terminal 272 of the selective buck circuit module of this embodiment are respectively connected between the output terminal of the boost circuit module 250 and the input terminal of the source driving circuit module 300 .

[0143] Specifically, the input end 271 of the selected buck circuit module is connected to the output end of the boost circuit, and is used to receive the standard voltage signal output by the control board 100 and boosted by the boost circuit. The output end 272 of the selected buck circuit module is connected to the input end of the source driver circuit module 300, thereby transmitting the VAA voltage to the source driver circuit module 300.

[0144] Fig.11 is a schematic diagram of a method for driving a display panel according to an embodiment of the present application, such as Fig.11 As shown, the present application also discloses a driving method of a display panel 20, the driving method of the display panel 20 is used to drive a driving circuit 30 of the display panel, and the driving method of the display panel 20 comprises the steps of:

[0145] S1: The control board outputs a standard voltage signal;

[0146] S2: the step-down circuit module is selected to receive the standard voltage signal, and when the standard voltage signal is higher than or equal to a threshold voltage, the voltage value of the standard voltage signal is controlled to be lowered to less than the threshold voltage and then output to the boost circuit module; when the standard voltage signal is less than the threshold voltage, the standard voltage signal is directly output to the boost circuit module;

[0147] S3: the boost circuit module receives the voltage signal output by the selected buck circuit module, and boosts the voltage signal output by the selected buck circuit module to a VAA voltage, and outputs the VAA voltage to the source drive circuit module.

[0148] The present application reduces the voltage entering the source driver circuit module 300 by adding a selective step-down circuit module 200, thereby ensuring that the difference between the voltage input to the source driver circuit module 300 and the output voltage of the source driver circuit module 300 is reduced, thereby avoiding heat loss in the transistor inside the source driver circuit module 300, thereby preventing the source driver circuit module 300 from heating up and avoiding display failure problems; and there is no need to attach a heat sink to the source driver circuit module 300, which can also reduce costs.

[0149] Furthermore, the selective buck circuit module 200 includes a selective control unit 210 , a first control switch 220 , a second control switch 230 and a buck control unit 240 .

[0150] S2: The step of selecting the step-down circuit module to receive the standard voltage signal, and when the standard voltage signal is higher than or equal to a threshold voltage, controlling the voltage value of the standard voltage signal to be reduced to less than the threshold voltage and then outputting it to the boost circuit module; when the standard voltage signal is less than the threshold voltage, directly outputting the standard voltage signal to the boost circuit module includes:

[0151] S21: the selection control unit receives the standard voltage signal;

[0152] S22: when the standard voltage signal is lower than the threshold voltage, controlling the first control switch to be turned on and controlling the second control switch to be turned off, the standard voltage signal is directly output to the boost circuit module through the first control switch;

[0153] S23: When the standard voltage signal is higher than or equal to the threshold voltage, the first control switch is controlled to be closed and the second control switch is controlled to be opened, and the standard voltage signal is output to the step-down control unit through the second control switch. The step-down control unit reduces the standard voltage signal to a level less than or equal to the threshold signal and then outputs it to the boost circuit module.

[0154] Thus, the standard voltage signal output by the control board 100 which is higher than or equal to the threshold voltage is stepped down and then processed by the boost circuit module 250 to output a VAA voltage that meets the requirements.

[0155] The technical solution of the present application can be widely used in various display panels, such as TN (Twisted Nematic) display panel, IPS (In-Plane Switching) display panel, VA (Vertical Alignment) display panel, MVA (Multi-Domain Vertical Alignment) display panel, all of which are applicable to the above solution.

[0156] It should be noted that the limitations on the various steps involved in this solution, without affecting the implementation of the specific solution, are not deemed to limit the order of the steps. The steps written in front can be executed first, or later, or even simultaneously. As long as this solution can be implemented, it should be deemed to fall within the scope of protection of this application.

[0157] It should be noted that the inventive concept of the present application can form a large number of embodiments, but the length of the application document is limited and it is impossible to list them one by one. Therefore, under the premise of no conflict, the embodiments or technical features described above can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effects will be enhanced.

[0158] The above content is a further detailed description of the present application in combination with specific optional implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be deemed to fall within the scope of protection of the present application.

Claims

1. A driving circuit for a display panel, characterized in that: The driving circuit of the display panel includes a control board, a voltage-reducing circuit module, a voltage-boosting circuit module and a source driving circuit module; The output end of the control board is connected to the input end of the boost circuit module, and the output end of the boost circuit is connected to the input end of the source drive circuit module; The input end and the output end of the selective buck circuit module are respectively connected between the output end of the control board and the input end of the boost circuit module, or the input end and the output end of the selective buck circuit module are respectively connected between the output end of the boost circuit module and the input end of the source drive circuit module; The selective step-down circuit module is used to reduce the standard voltage signal output by the control board that is greater than or equal to the threshold voltage to less than the threshold voltage before outputting it, and at the same time directly output the standard voltage signal output by the control board that is less than the threshold voltage.

2. The driving circuit of the display panel according to claim 1, characterized in that: The input end of the voltage-reducing circuit module is connected to the output end of the control board for receiving the standard voltage signal output by the control board, and the output end of the voltage-reducing circuit module is connected to the input end of the voltage-boosting circuit module.

3. The driving circuit of the display panel according to claim 2, characterized in that: The selective buck circuit module includes a selective control unit, a first control switch, a second control switch and a buck control unit; The input end of the selection control unit is connected to the output end of the control board, and the output end of the selection control unit is connected to the control end of the first control switch and the control end of the second control unit; The input end of the first control switch is connected to the output end of the control board, and the output end of the first control switch is connected to the input end of the boost circuit module; The input end of the second control switch is connected to the output end of the control board, the output end of the second control switch is connected to the input end of the step-down control unit, and the output end of the step-down control unit is connected to the input end of the boost circuit module; The selection control unit is used to select and control one of the first control switch and the second control switch to be turned on and the other to be turned off according to the relationship between the input standard voltage signal and the threshold voltage; the step-down control unit is used to reduce the voltage value of the input signal that is greater than or equal to the threshold voltage.

4. The driving circuit of the display panel according to claim 3, characterized in that: The selection control unit includes a voltage stabilizing diode, a first resistor, a second resistor, a first N-type transistor and a second N-type transistor; The cathode of the voltage zener diode is connected to the output end of the control board, the anode of the voltage zener diode is connected to the control end of the first N-type transistor, one end of the first resistor is connected to the output end of the control board, and the other end is connected to the input end of the first N-type transistor, and the output end of the first N-type transistor is grounded; The control end of the second N-type transistor is connected between the first resistor and the input end of the first N-type transistor, one end of the second resistor is connected to the output end of the control board, and the other end is connected to the input end of the second N-type transistor, and the output end of the second N-type transistor is grounded; The first control switch comprises a first P-type transistor; The control end of the first P-type transistor is connected between the second resistor and the input end of the second N-type transistor, the input end of the first P-type transistor is connected to the output end of the control board, and the output end of the first P-type transistor is connected to the input end of the boost circuit module; The second control switch includes a second P-type transistor; The control end of the second P-type transistor is connected to the first resistor and the input end of the first N-type transistor, and the input end of the second P-type transistor is connected to the output end of the control board; The voltage reduction control unit includes a voltage dividing resistor; Two ends of the voltage-dividing resistor are respectively connected to the output end of the second P-type transistor and the input end of the boost circuit module.

5. The driving circuit of the display panel according to claim 3, characterized in that: The selection control unit includes a voltage stabilizing diode, a first resistor, a second resistor, a first N-type transistor and a second N-type transistor; The cathode of the voltage zener diode is connected to the output end of the control board, the anode of the voltage zener diode is connected to the control end of the first N-type transistor, one end of the first resistor is connected to the output end of the control board, and the other end is connected to the input end of the first N-type transistor, and the output end of the first N-type transistor is grounded; The control end of the second N-type transistor is connected between the first resistor and the input end of the first N-type transistor, one end of the second resistor is connected to the output end of the control board, and the other end is connected to the input end of the second N-type transistor, and the output end of the second N-type transistor is grounded; The first control switch comprises a first P-type transistor; The control end of the first P-type transistor is connected between the second resistor and the input end of the second N-type transistor, the input end of the first P-type transistor is connected to the output end of the control board, and the output end of the first P-type transistor is connected to the input end of the boost circuit module; The second control switch includes a second P-type transistor; The control end of the second P-type transistor is connected to the first resistor and the input end of the first N-type transistor, and the input end of the second P-type transistor is connected to the output end of the control board; The step-down control unit includes a first transistor; The input end of the first transistor is connected to the output end of the second P-type transistor, and the output end of the first transistor is connected to the output end of the control board; The control terminal of the first transistor is used to receive a control signal to adjust the on-resistance of the first transistor.

6. The driving circuit of the display panel according to claim 1, characterized in that: The driving circuit of the display panel further includes a first voltage adjustment module, a second voltage adjustment module, a first buck conversion circuit, a second buck conversion circuit and a gate driving circuit module; The input end of the first voltage adjustment module is connected to the input end of the control board, and the output end of the first voltage adjustment module is connected to the input end of the gate drive circuit module; The input end of the second voltage adjustment module is connected to the input end of the control board, and the output end of the second voltage adjustment module is connected to the input end of the gate drive circuit module; The input end of the first buck conversion circuit is connected to the input end of the control board, and the output end of the first buck conversion circuit is connected to the input end of the source drive circuit module; The input end of the second buck conversion circuit is connected to the input end of the control board, and the output end of the second buck conversion circuit is connected to the input end of the source drive circuit module; The selective buck circuit module is connected only between the control board and the boost circuit module, or the selective buck circuit module is connected only between the boost circuit module and the source driving circuit module; The first voltage adjustment module is used to generate a VGH signal; the second voltage adjustment module is used to generate a VGL signal; the first step-down conversion circuit is used to generate a Vlogic signal; the second step-down conversion circuit is used to generate a Vcore signal; the selection step-down circuit module and the boost circuit module are used together to generate a VAA voltage.

7. The driving circuit of the display panel according to claim 4 or 5, characterized in that: The output voltage of the control board is 12V, the breakdown voltage of the voltage regulator diode is 12V, and the resistance value of the step-down control unit is set to 5 ohms.

8. A method for driving a display panel, characterized in that: The display panel driving method is used to drive the display panel driving circuit according to any one of claims 1 to 7, and the display panel driving method comprises the steps of: The control board outputs a standard voltage signal; The step-down circuit module receives the standard voltage signal, and when the standard voltage signal is higher than or equal to a threshold voltage, controls the voltage value of the standard voltage signal to be reduced to less than the threshold voltage and then outputs it to the boost circuit module; when the standard voltage signal is less than the threshold voltage, directly outputs the standard voltage signal to the boost circuit module; The boost circuit module receives the voltage signal output by the selected buck circuit module, and boosts the voltage signal output by the selected buck circuit module to a VAA voltage, and outputs the voltage to the source drive circuit module.

9. The method for driving a display panel according to claim 8, wherein: The selective buck circuit module includes a selective control unit, a first control switch, a second control switch and a buck control unit; The voltage-reducing circuit module is configured to receive the standard voltage signal, and when the standard voltage signal is higher than or equal to a threshold voltage, the voltage value of the standard voltage signal is controlled to be lower than the threshold voltage and then output to the voltage-reducing circuit module; When the standard voltage signal is less than the threshold voltage, the step of directly outputting the standard voltage signal to the boost circuit module includes: The selection control unit receives the standard voltage signal; When the standard voltage signal is lower than the threshold voltage, the first control switch is controlled to be turned on and the second control switch is controlled to be turned off, and the standard voltage signal is directly output to the boost circuit module through the first control switch; When the standard voltage signal is higher than or equal to the threshold voltage, the first control switch is controlled to be closed and the second control switch is controlled to be opened, and the standard voltage signal is output to the step-down control unit through the second control switch. The step-down control unit reduces the standard voltage signal to a level less than or equal to the threshold signal and then outputs it to the boost circuit module.

10. A display device, characterized in that: The display device comprises a display panel and a driving circuit for the display panel as claimed in any one of claims 1 to 6, wherein the driving circuit for the display panel is connected to the display panel to provide a driving signal for the display panel.

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