Display screen power supply driving device and method

Abstract

The invention provides a display screen power supply driving device and method. The method comprises the following steps: step 1, receiving a startup command of a display module; step 2, a waveform control unit in the control module generates a voltage control waveform with an adjustable duty ratio according to the power-on time sequence of each target voltage and controls the duty ratio of the voltage control waveform to change according to a preset rule; step 3, a driving module receives the voltage control waveform, generates a driving control signal, controls the switch of a switch module according to the driving control signal, and generates a display module power supply voltage according with a preset rising rate; and 4, judging whether the display module is started or not, if so, maintaining the duty ratio of the driving control signal of each target voltage to be 100%, and if not, returning to the step 3. According to the invention, a series of abnormal display problems caused by the fact that the output power supply voltage of the charge pump is pulled down due to overlarge power-on transient current in the current scheme are effectively solved, and the reliability of the product is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display screen power driving device and method. Background Art

[0002] Among the various operating voltages of LCD screens, the following four voltages are more important: gate high voltage VGH, gate low voltage VGL, drive positive voltage VSP, and drive negative voltage VSN. Among them, 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. Generally speaking, VGH is the highest of the four voltage values.

[0003] As we all know, LCD screens follow a strict power-on sequence, and the current power-on sequence is achieved by controlling an electronic switch through the high and low levels of the processor's I / O port. Therefore, at the moment the LCD screen is powered on, the timing control switch is suddenly turned on, and the parallel capacitors on the above-mentioned power supply networks are quickly charged, resulting in a large load and large transient current, which can easily pull down these power supplies, resulting in abnormal power supply voltage of the display screen, causing a series of display abnormalities, such as flickering screen, black screen and other problems, reducing the reliability of the product. Summary of the invention

[0004] The present invention provides a display screen power driving device and method, aiming to solve the defects in the prior art, effectively solve a series of display abnormality problems caused by excessive power-on transient current causing the charge pump output power supply voltage to be pulled down in the current solution, and improve the reliability of the product.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

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

[0007] A power supply module, used for providing a target voltage of 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] A control module, used to provide a voltage control signal containing timing information, wherein the voltage control signal is a waveform with an adjustable duty cycle, so that the target voltage is switched according to the timing information, and 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 driving module, the second driving module and the third driving module are used to process the voltage control signal to generate a driving control signal, including a driving input terminal and a driving 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 driving control signal, and include a control terminal, a voltage input terminal and a voltage output terminal;

[0011] A display module, used to receive the target voltage and realize the display function, including a first voltage input port for receiving a gate high voltage VGH, a second voltage input port for receiving a gate low voltage VGL, a third voltage input port for driving a negative voltage VSN, and a fourth voltage input port for driving a 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 connected to the voltage input ends of the first switch module, the second switch module and the third switch module respectively, and the fourth voltage output port is connected to the fourth voltage input port of the display module;

[0013] The voltage output ends 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, and the control ends of the first switch module, the second switch module and the third switch module are respectively connected to the driving output ends of the first driving module, the second driving module and the third driving module;

[0014] The driving input ends of the first driving module, the second driving module and the third driving 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 switch module is a PMOS tube, and the second switch module and the third switch module are NMOS tubes.

[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, the first resistor, and one end of 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 resistor and the sixth resistor, 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, the third resistor, and one end of 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 resistor and the tenth resistor, 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, the seventh resistor, and one end of 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 display screen power driving method, comprising:

[0023] Step 1, receiving a power-on command from the display module;

[0024] Step 2: The waveform control unit in the control module generates a voltage control waveform with adjustable duty cycle according to the power-on timing 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 driving module receives the voltage control waveform, generates a driving control signal, and controls the switch of the switch module according to the driving control signal to generate a display module power supply voltage that meets a preset rising rate;

[0026] Step 4: determine whether the display module has completed startup, if yes, maintain the duty cycle of the drive control signal of 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 the present invention are as follows: the present invention can realize load starting current control, load capacitor slow charging, flexibly control the rise time of the voltage waveform, control the power-on transient current within the acceptable range of the charge pump output power supply, and ensure the stability of the output power supply voltage, thereby effectively solving a series of display abnormality problems caused by the charge pump output power supply voltage being pulled down due to excessive power-on transient current in the current solution, thereby improving the reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0031] Figure 2 The present invention is a circuit diagram of a display screen power drive device. DETAILED DESCRIPTION

[0032] The following specifically describes the embodiments of the present invention in conjunction with the accompanying drawings, which are only for reference and illustration and do not constitute a limitation on the scope of patent protection of the present invention.

[0033] In the process described in the specification, claims or drawings of the present invention, the serial numbers of each step (such as step 10, 20, etc.) are included. The serial numbers are only used to distinguish the steps, and the serial numbers themselves do not represent any execution order. It should be noted that the descriptions such as "first" and "second" in this article are only used to distinguish the description objects, etc., and do not represent the order of precedence, nor do they mean 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] A power supply module, used for providing a target voltage of 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] A control module, used to provide a voltage control signal containing timing information, wherein the voltage control signal is a waveform with an adjustable duty cycle, so that the target voltage is switched according to the timing information, and 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 driving module, the second driving module and the third driving module are used to process the voltage control signal to generate a driving control signal, including a driving input terminal and a driving 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 driving control signal, and include a control terminal, a voltage input terminal and a voltage output terminal;

[0040] A display module, used to receive the target voltage and realize the display function, including a first voltage input port for receiving a gate high voltage VGH, a second voltage input port for receiving a gate low voltage VGL, a third voltage input port for driving a negative voltage VSN, and a fourth voltage input port for driving a 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 connected to the voltage input ends of the first switch module, the second switch module and the third switch module respectively, and the fourth voltage output port is connected to the fourth voltage input port of the display module;

[0042] The voltage output ends 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, and the control ends of the first switch module, the second switch module and the third switch module are respectively connected to the driving output ends of the first driving module, the second driving module and the third driving module;

[0043] The driving input ends of the first driving module, the second driving module and the third driving 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 screen power driving device described in Example 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, 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 switch module is a PMOS tube, and the second switch module and the third switch module are NMOS tubes.

[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, the first resistor R101, and one end of the first capacitor C101. The other ends of the first resistor R101 and the first capacitor C101 are 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, the third resistor R201, and one end of 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 Q201 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, the seventh resistor R301, and one end of 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] The display module receives the power-on command, the system starts to power on, and the power module simultaneously outputs four voltages, namely VSP (6.7V), VSN (-6.7V), VGL (-10.5V), and VGH (12V). According to the power-on timing of the display module, the power-on sequence of the above voltages is VSP→VSN→VGL→VGH:

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

[0057] B) Then, 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 the third field effect transistor M301 is driven to be turned on, and the VSN power 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 adjustable duty cycle (e.g., PWM wave), wherein the duty cycle increases from an initial value (e.g., 1%) to 100% at a preset step size (e.g., 5%) within a preset time (e.g., within 200 ms), thereby driving the first transistor Q101 to quickly turn off / on. During this period, the first field effect transistor M101 operates in a variable resistance range, so that the VGH power supply current output to the display module is stable and controllable, thereby avoiding problems such as black screen flashing caused by transient large current of the switch.

[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 the second field effect transistor M201 is driven to be turned on, and the VGL power supply is supplied to the display module.

[0060] E) The display module power supply input is completed and works 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 of the display module.

[0064] Step 2: The waveform control unit in the control module generates a voltage control waveform with adjustable duty cycle according to the power-on timing 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 driving module receives the voltage control waveform, generates a driving control signal, and controls the switch of the switching module according to the driving control signal to generate a display module power supply voltage that meets a preset rising rate.

[0066] Step 4: determine whether the display module has completed startup, if yes, maintain the duty cycle of the drive control signal of 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 disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of protection of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A display screen power driving device, characterized in that: include: A power supply module, used for providing a 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; A control module, used to provide a voltage control signal containing timing information, wherein the voltage control signal is a waveform with an adjustable duty cycle, so that the target voltage is switched according to the timing information, and 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 driving module, the second driving module and the third driving module are used to process the voltage control signal to generate a driving control signal, including a driving input terminal and a driving 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 driving control signal, and include a control terminal, a voltage input terminal and a voltage output terminal; A display module, used to receive the target voltage and realize the display function, including a first voltage input port for receiving a gate high voltage VGH, a second voltage input port for receiving a gate low voltage VGL, a third voltage input port for driving a negative voltage VSN, and a fourth voltage input port for driving a positive voltage VSP; The first voltage output port, the second voltage output port and the third voltage output port of the power module are connected to the voltage input ends of the first switch module, the second switch module and the third switch module respectively, and the fourth voltage output port is connected to the fourth voltage input port of the display module; The voltage output ends 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, and the control ends of the first switch module, the second switch module and the third switch module are respectively connected to the driving output ends of the first driving module, the second driving module and the third driving module; The driving input ends of the first driving module, the second driving module and the third driving 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.

2. The display screen power driving device according to claim 1, characterized in that: The first switch module is a PMOS tube, and the second switch module and the third switch module are NMOS tubes.

3. The display screen power driving device according to claim 2, characterized in that: 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, the first resistor, and one end of 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.

4. The display screen power driving device according to claim 2, characterized in that: 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 resistor and the sixth resistor, 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, the third resistor, and one end of 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.

5. The display screen power driving device according to claim 2, characterized in that: The third driving module includes: a third triode, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and a third capacitor. The third triode is a PNP triode. The base of the third triode is grounded, the emitter is connected to one end of the ninth resistor and the tenth resistor, 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 tube, the seventh resistor, and one end of 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 tube.

6. The display screen power driving device according to any one of claims 1 to 5, characterized in that: The control module is a microprocessor.

7. The display screen power driving device according to claim 6, 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.

8. A display screen power driving method, characterized in that: include: Step 1, receiving a power-on command from the display module; Step 2: The waveform control unit in the control module generates a voltage control waveform with adjustable duty cycle according to the power-on timing of each target voltage and controls the duty cycle of the voltage control waveform to change according to a preset rule; Step 3: The driving module receives the voltage control waveform, generates a driving control signal, and controls the switch of the switch module according to the driving control signal to generate a display module power supply voltage that meets a preset rising rate; Step 4: determine whether the display module has completed startup, if yes, maintain the duty cycle of the drive control signal of each target voltage at 100%, otherwise return to step 3.

9. The display screen power driving method according to claim 1, characterized in that: The voltage control waveform is a PWM waveform.

10. The display screen power driving method according to claim 9, characterized in that: The preset rule is to increase linearly with a preset slope.

Images