A power supply driving device and method for a display screen

Abstract

This invention provides a display screen power supply driving device and method. The method includes: Step 1, receiving a power-on command from the display module; Step 2, a waveform control unit in the control module generates a voltage control waveform with an adjustable duty cycle according to the power-on sequence of each target voltage and controls the duty cycle of the voltage control waveform to change according to a preset rule; Step 3, a drive module receives the voltage control waveform, generates a drive control signal, and controls the switching module according to the drive control signal to generate a display module power supply voltage that conforms to a preset rise rate; Step 4, determining whether the display module has completed startup. If so, the duty cycle of the drive control signal for each target voltage is maintained at 100%; otherwise, the process returns to Step 3. This invention effectively solves a series of display abnormality problems caused by excessive transient current during power-on, which leads to a drop in the output power supply voltage of the charge pump, thus improving product reliability.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a power supply driving device and method for a display screen. Background Technology

[0002] Among the various operating voltages of an LCD screen, the following four voltages are particularly important: gate high voltage VGH, gate low voltage VGL, positive drive voltage VSP, and negative drive voltage VSN. VGH and VSP are generally positive voltages, while VGL and VSN are generally negative voltages. The specific voltage values ​​vary depending on the type of LCD screen, but generally, VGH has the highest value among these four voltages.

[0003] As is well known, LCD screens follow a strict power-on sequence, which is currently achieved by controlling an electronic switch via high and low levels through the processor's I / O ports. Therefore, at the instant the LCD screen powers on, the sudden activation of the sequence control switch causes the parallel capacitors on the aforementioned power networks to charge rapidly, resulting in a large load and high transient current. This can easily pull these power supplies low, leading to abnormal power supply voltages for the display screen and causing a series of display malfunctions, such as screen flickering and black screens, thus reducing product reliability. Summary of the Invention

[0004] This invention provides a display screen power supply driving device and method, which aims to overcome the defects in the prior art and effectively solve a series of display abnormality problems caused by the excessive transient current during power-on, which leads to the low output power voltage of the charge pump, thereby improving the reliability of the product.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In one aspect, the present invention provides a display screen power driving device, comprising:

[0007] The power supply module is used to provide the target voltage for the display module, including a first voltage output port for generating a gate high voltage VGH, a second voltage output port for generating a gate low voltage VGL, a third voltage output port for driving a negative voltage VSN, and a fourth voltage output port for driving a positive voltage VSP.

[0008] The control module is used to provide a voltage control signal containing timing information. The voltage control signal is a waveform with an adjustable duty cycle, so that the target voltage switches according to the timing information. It includes a waveform control unit and a first control signal output port, a second control signal output port, and a third control signal output port.

[0009] The first drive module, the second drive module, and the third drive module are used to process the voltage control signal and generate a drive control signal, including a drive input terminal and a drive output terminal.

[0010] The first switch module, the second switch module, and the third switch module are used to control the output of the target voltage according to the drive control signal, and include a control terminal, a voltage input terminal, and a voltage output terminal.

[0011] The display module is used to receive the target voltage and realize the display function, including a first voltage input port for receiving the gate high voltage VGH, a second voltage input port for receiving the gate low voltage VGL, a third voltage input port for driving the negative voltage VSN, and a fourth voltage input port for driving the positive voltage VSP.

[0012] The first voltage output port, the second voltage output port, and the third voltage output port of the power module are respectively connected to the voltage input terminals of the first switch module, the second switch module, and the third switch module, and the fourth voltage output port is connected to the fourth voltage input port of the display module.

[0013] The voltage output terminals of the first switch module, the second switch module, and the third switch module are respectively connected to the first voltage input port, the second voltage input port, and the third voltage input port of the display module. The control terminals of the first switch module, the second switch module, and the third switch module are respectively connected to the drive output terminals of the first drive module, the second drive module, and the third drive module.

[0014] The drive input terminals of the first drive module, the second drive module, and the third drive module are respectively connected to the first control signal output port, the second control signal output port, and the third control signal output port of the control module;

[0015] The first control signal output port, the second control signal output port, and the third control signal output port are connected to the waveform control unit.

[0016] Specifically, the control module is a microprocessor.

[0017] Specifically, the first control signal output port, the second control signal output port, and the third control signal output port are GPIO ports.

[0018] Specifically, the first switching module is a PMOS transistor, and the second and third switching modules are NMOS transistors.

[0019] Specifically, the first driving module includes: a first transistor, a first resistor, a second resistor, and a first capacitor. The first transistor is an NPN transistor. The base of the first transistor is connected to the first control signal output port, the emitter is grounded, the collector is connected to one end of the second resistor, the other end of the second resistor is connected to the gate of the first field-effect transistor, one end of the first resistor and the first capacitor, and the other end of the first resistor and the first capacitor is connected to the source of the first field-effect transistor.

[0020] Specifically, the second driving module includes: a second transistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a second capacitor. The second transistor is a PNP transistor. The base of the second transistor is grounded, the emitter is connected to one end of the fifth and sixth resistors, the collector is connected to one end of the fourth resistor, the other end of the fifth resistor is connected to the second control signal output port, the other end of the sixth resistor is grounded, the other end of the fourth resistor is connected to the gate of the second field-effect transistor, one end of the third resistor and the second capacitor, and the other end of the third resistor and the second capacitor is connected to the source of the second field-effect transistor.

[0021] Specifically, the third driving module includes: a third transistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and a third capacitor. The third transistor is a PNP transistor. The base of the third transistor is grounded, the emitter is connected to one end of the ninth and tenth resistors, the collector is connected to one end of the eighth resistor, the other end of the ninth resistor is connected to the third control signal output port, the other end of the tenth resistor is grounded, the other end of the eighth resistor is connected to the gate of the third field-effect transistor, one end of the seventh resistor and the third capacitor, and the other end of the seventh resistor and the third capacitor is connected to the source of the third field-effect transistor.

[0022] Another aspect of the present invention provides a power supply driving method for a display screen, comprising:

[0023] Step 1: Receive the power-on command from the display module;

[0024] Step 2: The waveform control unit in the control module generates a voltage control waveform with an adjustable duty cycle according to the power-on sequence of each target voltage and controls the duty cycle of the voltage control waveform to change according to a preset rule.

[0025] Step 3: The drive module receives the voltage control waveform, generates a drive control signal, and controls the switch module to switch according to the drive control signal to generate a display module power supply voltage that conforms to the preset rise rate.

[0026] Step 4: Determine whether the display module has been started. If so, maintain the duty cycle of the drive control signals for each target voltage at 100%. Otherwise, return to step 3.

[0027] Specifically, the voltage control waveform is a PWM waveform.

[0028] Specifically, the preset rule is to increase linearly with a preset slope.

[0029] The beneficial effects of this invention are as follows: This invention can realize load start-up current control, load capacitor slow charging, and flexible control of voltage waveform rise time. It controls the power-on transient current within the acceptable range of the charge pump output power supply, ensuring stable output power supply voltage. This effectively solves a series of display abnormality problems caused by excessive power-on transient current pulling down the charge pump output power supply voltage in the current solution, and improves product reliability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the display screen power drive device of the present invention;

[0031] Figure 2 This is a circuit diagram of the display screen power drive device of the present invention. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The drawings are for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention.

[0033] In the process described in the specification, claims, or drawings of this invention, each step is numbered (e.g., step 10, 20, etc.). These numbers are used only to distinguish the steps and do not represent any execution order. It should be noted that the terms "first," "second," etc., used herein are only for distinguishing the objects being described and do not represent a chronological order, nor do they indicate that "first," "second," etc., are different types.

[0034] Example 1

[0035] like Figure 1 As shown, this embodiment provides a display screen power driving device, including:

[0036] The power supply module is used to provide the target voltage for the display module, including a first voltage output port for generating a gate high voltage VGH, a second voltage output port for generating a gate low voltage VGL, a third voltage output port for driving a negative voltage VSN, and a fourth voltage output port for driving a positive voltage VSP.

[0037] The control module is used to provide a voltage control signal containing timing information. The voltage control signal is a waveform with an adjustable duty cycle, so that the target voltage switches according to the timing information. It includes a waveform control unit and a first control signal output port, a second control signal output port, and a third control signal output port.

[0038] The first drive module, the second drive module, and the third drive module are used to process the voltage control signal and generate a drive control signal, including a drive input terminal and a drive output terminal.

[0039] The first switch module, the second switch module, and the third switch module are used to control the output of the target voltage according to the drive control signal, and include a control terminal, a voltage input terminal, and a voltage output terminal.

[0040] The display module is used to receive the target voltage and realize the display function, including a first voltage input port for receiving the gate high voltage VGH, a second voltage input port for receiving the gate low voltage VGL, a third voltage input port for driving the negative voltage VSN, and a fourth voltage input port for driving the positive voltage VSP.

[0041] The first voltage output port, the second voltage output port, and the third voltage output port of the power module are respectively connected to the voltage input terminals of the first switch module, the second switch module, and the third switch module, and the fourth voltage output port is connected to the fourth voltage input port of the display module.

[0042] The voltage output terminals of the first switch module, the second switch module, and the third switch module are respectively connected to the first voltage input port, the second voltage input port, and the third voltage input port of the display module. The control terminals of the first switch module, the second switch module, and the third switch module are respectively connected to the drive output terminals of the first drive module, the second drive module, and the third drive module.

[0043] The drive input terminals of the first drive module, the second drive module, and the third drive module are respectively connected to the first control signal output port, the second control signal output port, and the third control signal output port of the control module;

[0044] The first control signal output port, the second control signal output port, and the third control signal output port are connected to the waveform control unit.

[0045] Example 2

[0046] like Figure 2 As shown, this embodiment provides a specific implementation of the display power drive device described in Embodiment 1.

[0047] In this embodiment, the control module is a microprocessor (MCU).

[0048] In this embodiment, the first control signal output port, the second control signal output port, and the third control signal output port are GPIO ports.

[0049] For example, such as Figure 2 As shown, the first control signal output port is GPIO1, the second control signal output port is GPIO2, and the third control signal output port is GPIO3.

[0050] In this embodiment, the first switching module is a PMOS transistor, and the second and third switching modules are NMOS transistors.

[0051] In this embodiment, the first driving module includes: a first transistor Q101, a first resistor R101, a second resistor R102, and a first capacitor C101. The first transistor Q101 is an NPN transistor. The base of the first transistor Q101 is connected to the first control signal output port, the emitter is grounded, and the collector is connected to one end of the second resistor R102. The other end of the second resistor R102 is connected to the gate of the first field-effect transistor M101, one end of the first resistor R101 and the first capacitor C101, and the other end of the first resistor R101 and the first capacitor C101 is connected to the source of the first field-effect transistor M101.

[0052] In this embodiment, the second driving module includes: a second transistor Q201, a third resistor R201, a fourth resistor R202, a fifth resistor R203, a sixth resistor R204, and a second capacitor C201. The second transistor Q201 is a PNP transistor. The base of the second transistor Q201 is grounded, the emitter is connected to one end of the fifth resistor R203 and the sixth resistor R204, the collector is connected to one end of the fourth resistor R202, the other end of the fifth resistor R203 is connected to the second control signal output port, the other end of the sixth resistor R204 is grounded, the other end of the fourth resistor R202 is connected to the gate of the second field-effect transistor M201, one end of the third resistor R201 and the second capacitor C201, and the other end of the third resistor R201 and the second capacitor C201 is connected to the source of the second field-effect transistor M201.

[0053] In this embodiment, the third driving module includes: a third transistor Q301, a seventh resistor R301, an eighth resistor R302, a ninth resistor R303, a tenth resistor R304, and a third capacitor C301. The third transistor Q301 is a PNP transistor. The base of the third transistor Q301 is grounded, the emitter is connected to one end of the ninth resistor R303 and the tenth resistor R304, the collector is connected to one end of the eighth resistor R302, the other end of the ninth resistor R303 is connected to the third control signal output port, the other end of the tenth resistor R304 is grounded, the other end of the eighth resistor R302 is connected to the gate of the third field-effect transistor M301, one end of the seventh resistor R301 and the third capacitor C301, and the other end of the seventh resistor R301 and the third capacitor C301 is connected to the source of the third field-effect transistor M301.

[0054] The circuit operation process in this embodiment is as follows:

[0055] Upon receiving the power-on command, the display module initiates system power-on. The power supply module simultaneously outputs four voltages: VSP (6.7V), VSN (-6.7V), VGL (-10.5V), and VGH (12V). According to the display module's power-on sequence, the power-on order of these voltages is VSP→VSN→VGL→VGH.

[0056] A) When the power module is enabled, the display module directly receives VSP power input;

[0057] B) Next, the waveform control unit controls the third control signal output port GPIO3 to output a high level, the third transistor Q301 is turned on, and at the same time, the third field-effect transistor M301 is turned on, and the VSN power supply is supplied to the display module.

[0058] C) Subsequently, the waveform control unit controls the first control signal output port GPIO1 to output a waveform with an adjustable duty cycle (e.g., a PWM wave). Its duty cycle increases from an initial value (e.g., 1%) to 100% in a preset step size (e.g., 5%) within a preset time (e.g., within 200ms), thereby driving the first transistor Q101 to quickly turn off / on. During this period, the first field-effect transistor M101 operates in the variable resistance range, realizing stable and controllable VGH power supply current output to the display module, thereby avoiding problems such as black screen and screen flickering caused by large transient current during switching.

[0059] D) Finally, the waveform control unit controls the second control signal output port GPIO2 to output a high level, the second transistor Q201 is turned on, and at the same time, the second field-effect transistor M201 is driven to turn on, and the VGL power supply is supplied to the display module.

[0060] E) The power supply input for the display module is complete and it is working normally.

[0061] Example 3

[0062] This embodiment provides a display screen power driving method based on the display screen driving device described in Embodiment 1, including:

[0063] Step 1: Receive the power-on command from the display module.

[0064] Step 2: The waveform control unit in the control module generates a voltage control waveform with an adjustable duty cycle according to the power-on sequence of each target voltage, and controls the duty cycle of the voltage control waveform to change according to a preset rule.

[0065] Step 3: The drive module receives the voltage control waveform, generates a drive control signal, and controls the switch module to switch according to the drive control signal to generate a display module power supply voltage that conforms to the preset rise rate.

[0066] Step 4: Determine whether the display module has been started. If so, maintain the duty cycle of the drive control signals for each target voltage at 100%. Otherwise, return to step 3.

[0067] In this embodiment, the voltage control waveform is a PWM waveform.

[0068] In this embodiment, the preset rule is to increase linearly with a preset slope.

[0069] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A power supply driving device for a display screen, characterized in that, include: The power supply module is used to provide the target voltage for the display module, including a first voltage output port for generating a gate high voltage VGH, a second voltage output port for generating a gate low voltage VGL, a third voltage output port for driving a negative voltage VSN, and a fourth voltage output port for driving a positive voltage VSP. The control module is used to provide a voltage control signal containing timing information. The voltage control signal is a waveform with an adjustable duty cycle, so that the target voltage switches according to the timing information. It includes a waveform control unit and a first control signal output port, a second control signal output port, and a third control signal output port. The first drive module, the second drive module, and the third drive module are used to process the voltage control signal and generate a drive control signal, including a drive input terminal and a drive output terminal. The first switch module, the second switch module, and the third switch module are used to control the output of the target voltage according to the drive control signal, and include a control terminal, a voltage input terminal, and a voltage output terminal. The display module is used to receive the target voltage and realize the display function, including a first voltage input port for receiving the gate high voltage VGH, a second voltage input port for receiving the gate low voltage VGL, a third voltage input port for driving the negative voltage VSN, and a fourth voltage input port for driving the positive voltage VSP. The first voltage output port, the second voltage output port, and the third voltage output port of the power module are respectively connected to the voltage input terminals of the first switch module, the second switch module, and the third switch module, and the fourth voltage output port is connected to the fourth voltage input port of the display module. The voltage output terminals of the first switch module, the second switch module, and the third switch module are respectively connected to the first voltage input port, the second voltage input port, and the third voltage input port of the display module. The control terminals of the first switch module, the second switch module, and the third switch module are respectively connected to the drive output terminals of the first drive module, the second drive module, and the third drive module. The drive input terminals of the first drive module, the second drive module, and the third drive module are respectively connected to the first control signal output port, the second control signal output port, and the third control signal output port of the control module; The first control signal output port, the second control signal output port, and the third control signal output port are connected to the waveform control unit. The first driving module includes: a first transistor, a first resistor, a second resistor, and a first capacitor. The first transistor is an NPN transistor. The base of the first transistor is connected to the first control signal output port, the emitter is grounded, the collector is connected to one end of the second resistor, the other end of the second resistor is connected to the gate of the first field-effect transistor, one end of the first resistor and the first capacitor, and the other end of the first resistor and the first capacitor is connected to the source of the first field-effect transistor. The second driving module includes: a second transistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a second capacitor. The second transistor is a PNP transistor. The base of the second transistor is grounded, the emitter is connected to one end of the fifth and sixth resistors, the collector is connected to one end of the fourth resistor, the other end of the fifth resistor is connected to the second control signal output port, the other end of the sixth resistor is grounded, the other end of the fourth resistor is connected to the gate of the second field-effect transistor, one end of the third resistor and the second capacitor, and the other end of the third resistor and the second capacitor is connected to the source of the second field-effect transistor. The third driving module includes: a third transistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and a third capacitor. The third transistor is a PNP transistor. The base of the third transistor is grounded, the emitter is connected to one end of the ninth and tenth resistors, the collector is connected to one end of the eighth resistor, the other end of the ninth resistor is connected to the third control signal output port, the other end of the tenth resistor is grounded, the other end of the eighth resistor is connected to the gate of the third field-effect transistor, one end of the seventh resistor and the third capacitor, and the other end of the seventh resistor and the third capacitor is connected to the source of the third field-effect transistor.

2. The display screen power supply driving device according to claim 1, characterized in that, The first switching module is a PMOS transistor, and the second and third switching modules are NMOS transistors.

3. The display screen power supply driving device according to any one of claims 1 to 2, characterized in that, The control module is a microprocessor.

4. The display screen power drive device according to claim 3, characterized in that, The first control signal output port, the second control signal output port, and the third control signal output port are GPIO ports.

5. A driving method for the display screen power driving device according to any one of claims 1 to 4, characterized in that, include: Step 1: Receive the power-on command from the display module; Step 2: The waveform control unit in the control module generates a voltage control waveform with an adjustable duty cycle according to the power-on sequence of each target voltage and controls the duty cycle of the voltage control waveform to change according to a preset rule. Step 3: The drive module receives the voltage control waveform, generates a drive control signal, and controls the switch module to switch according to the drive control signal to generate a display module power supply voltage that conforms to the preset rise rate. Step 4: Determine whether the display module has been started. If so, maintain the duty cycle of the drive control signals for each target voltage at 100%. Otherwise, return to step 3.

6. The driving method according to claim 5, characterized in that, The voltage control waveform is a PWM waveform.

7. The driving method according to claim 6, characterized in that, The preset rule is to increase linearly with a preset slope.

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