LCD bias voltage adjustment circuit and apparatus
By independently adjusting the AVDD, VGH, VGL, and VCOM voltages through the LCD bias voltage adjustment circuit, the problems of inaccurate voltage adjustment and poor compatibility in the TFT color screen driving circuit are solved, achieving efficient and flexible voltage adjustment and improved hardware compatibility.
Patent Information
- Application Number
- CN202522399957.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-11-12
AI Technical Summary
In existing TFT color screen driving circuits, the voltages AVDD, VGH, VGL, and VCOM cannot be precisely adjusted, resulting in large voltage deviations, high correlation between the voltages, and the inability to control them individually. This leads to poor compatibility and requires modifications to the hardware circuit or PCB to adapt to different color screens, resulting in long development cycles, high costs, and low efficiency.
An LCD bias voltage adjustment circuit is adopted, which independently adjusts the AVDD, VGH, VGL and VCOM voltages through a controllable resistor module and a control module. The microcontroller controls the digital potentiometer to change the resistance value, so as to achieve precise control and independent adjustment and support the voltage requirements of different TFT color screens.
It enables independent control of AVDD, VGH, VGL and VCOM voltages, with a wide adjustment range, high precision, good compatibility, flexible and reliable adjustment, simplified hardware adjustment, and reduced development costs and cycle.
Smart Images
Figure CN224682601U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of LCD bias voltage, and in particular to an LCD bias voltage adjustment circuit and device. Background Technology
[0002] Currently, TFT-LCD technology manufacturing processes are extremely mature. With continuous improvements in automation levels and production yields, manufacturing costs have dropped significantly. For the vast majority of everyday applications, the performance of TFT color screens is more than sufficient. The decrease in cost and the reliability of performance have spurred a massive number of new application demands.
[0003] With its advantages in cost, lifespan, and reliability, TFT color screens have become a versatile component that can be easily embedded in various products after meeting the basic display performance (color, resolution, and brightness) requirements of most application scenarios. This makes it an undisputed "all-rounder" and mainstay in the current display technology field.
[0004] However, different TFT color screens have different LCD bias voltage parameters. Replacing a TFT color screen with a different brand requires adjusting the LCD bias voltage by modifying the hardware circuit to achieve the best display effect, resulting in poor compatibility.
[0005] In traditional TFT color screen driving circuits, bias voltages such as AVDD, VGH, VGL, and VCOM are basically adjusted through hardware circuits. However, these bias voltages are different for different TFT color screens. Therefore, it is usually necessary to modify the hardware circuit to adjust the different voltage requirements to meet the different color screens and achieve the best display effect. In some cases, it is even necessary to modify the PCB design to meet the requirements. This results in problems such as longer product development cycles, poor hardware compatibility, increased costs, and low efficiency.
[0006] In summary, current TFT color screen driving circuits have the following problems: 1. The voltages of AVDD, VGH, VGL and VCOM are all adjusted by hardware circuitry. The voltages of VGH and VGL cannot be adjusted precisely, and the voltage deviation is relatively large.
[0007] 2. The bias voltage cannot be controlled independently. Adjusting one voltage will affect the others. The correlation between the voltages is high, and they cannot be adjusted individually.
[0008] 3. Replacing the screen with a different color screen requires changes to the hardware circuitry or PCB, resulting in poor compatibility.
[0009] 4. Existing TFT color screen driving circuits cannot accurately control the power-on and power-off sequence of the liquid crystal, which can easily lead to display abnormalities, liquid crystal polarization, and other phenomena. Utility Model Content
[0010] To address the problems existing in the current LCD bias voltage adjustment process, this application provides an LCD bias voltage adjustment circuit and device.
[0011] In one aspect of this disclosure, an LCD bias voltage adjustment circuit is provided, comprising: The LCD bias voltage module is configured to output a bias voltage based on the input voltage; Multiple controllable resistor modules are independently connected to the LCD bias voltage module. The controllable resistor modules are configured to change the bias voltage output by the LCD bias voltage module by adjusting their own resistance. A control module is communicatively connected to multiple controllable resistor modules. The control module is configured to issue adjustment commands to the controllable resistor modules in response to adjustment requests, so as to adjust the resistance value of the controllable resistor modules.
[0012] By adopting the above technical solution, the control module adjusts the resistance value of the controllable resistor module, thereby adjusting the LCD bias voltage. The control module independently adjusts the resistance value of each controllable resistor module, thereby achieving independent adjustment of AVDD, VGH, VGL and VCOM. The adjustment range is wide, the adjustment accuracy is high, and it can meet the voltage requirements of different LCD color screens. The adjustment is flexible, reliable, convenient and quick, and has good compatibility.
[0013] Preferably, the bias voltage includes AVDD, VGL, VGH, and VCOM; The controllable resistor module has four components, which can change AVDD, VGL, VGH and VCOM by adjusting their own resistance values respectively.
[0014] By adopting the above technical solution, AVDD, VGL, VGH and VCOM can be adjusted through a controllable resistor module.
[0015] Preferably, the LCD bias voltage module includes a power management chip, which has an output pin, a feedback pin, and a power input pin. The output pin is connected to GND via a Schottky diode and / or capacitor. The feedback pin is connected to multiple controllable resistor modules; The power input pin is connected to GND via an NPN transistor and / or a capacitor.
[0016] By adopting the above technical solution, it is possible to adjust AVDD, VGL, VGH and VCOM under the control of the control module and multiple controllable resistor modules.
[0017] Preferably, the controllable resistor module includes a digital potentiometer.
[0018] By adopting the above technical solution, the control module can control the digital potentiometer to change its resistance value.
[0019] Preferably, the control module includes a microcontroller.
[0020] By adopting the above technical solution, it is easy to modify the program that controls and adjusts the LCD bias voltage.
[0021] Preferably, the microcontroller is a USB microcontroller; The LCD bias voltage adjustment circuit further includes: The TYPE-C interface module is configured to communicate with the device that initiated the adjustment request. USB to serial port module, for communication connection with USB microcontroller; The USB multiplexing module is communicatively connected to the TYPE-C interface module, the USB to serial port module, and the USB microcontroller. The USB multiplexing module is also communicatively connected to the USB selection interface module to enable communication between the adjustment request initiating device and the USB microcontroller.
[0022] By adopting the above technical solution, the device initiating the adjustment request can communicate and interact with the USB microcontroller through its own USB interface.
[0023] Preferably, the LCD bias voltage adjustment circuit further includes an LCD bias voltage output module, which is connected to the LCD bias voltage module.
[0024] Preferably, the control module is communicatively connected to a display module for real-time display of the current bias voltage set value and the actual output value.
[0025] By adopting the above technical solution, the display module can display the current bias voltage setting value and actual output value in real time, which is intuitive and convenient.
[0026] Preferably, the LCD bias voltage adjustment circuit further includes a power supply regulator module, which is connected to the controllable resistor module and the control module, and is used to supply power to the controllable resistor module and the control module.
[0027] By adopting the above technical solution, a stable power supply is provided to the controllable resistor module and the control module, ensuring their continuous normal operation.
[0028] In another aspect of this disclosure, an apparatus is provided, including the aforementioned LCD bias voltage adjustment circuit.
[0029] In summary, this application includes at least one of the following beneficial technical effects: The beneficial effects of the technical solution of this utility model are as follows: 1. The LCD bias voltage adjustment circuit of this application adjusts the resistance value of the controllable resistor module through a microcontroller, thereby adjusting the LCD bias voltage. The microcontroller independently adjusts the resistance value of each controllable resistor module, thereby achieving independent adjustment of AVDD, VGH, VGL and VCOM. It has a wide adjustment range and high adjustment accuracy, which can meet the voltage requirements of different LCD color screens. The adjustment is flexible and reliable, convenient and quick, and has good compatibility. Moreover, the built-in OLED display can display the currently set voltage value and the actual voltage value in real time, which is intuitive and convenient to use.
[0030] 2. The voltages AVDD, VGH, VGL and VCOM can be controlled independently and are not related to each other. The outputs can be turned off independently, thereby precisely controlling the power-on and power-off sequence. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of the LCD bias voltage adjustment circuit of this application.
[0032] Figure 2 This is a schematic diagram of the LCD bias voltage module of this application.
[0033] Figure 3 This is a schematic diagram of the LCD bias voltage output module of this application.
[0034] Figure 4 This is a schematic diagram of the four controllable resistor modules that adjust AVDD, VGL, VGH and VCOM according to this application.
[0035] Figure 5 This is a schematic diagram of the control module of this application.
[0036] Figure 6 This is a schematic diagram of the TYPE-C interface module of this application.
[0037] Figure 7 This is a schematic diagram of the USB to serial port module of this application.
[0038] Figure 8 This is a schematic diagram of the power supply regulator module of this application.
[0039] Figure 9 This is a schematic diagram of the display module of this application.
[0040] Figure 10 This is a schematic diagram of the USB multiplexing module of this application.
[0041] Figure 11 This is a schematic diagram of the USB selection interface module of this application. Detailed Implementation
[0042] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.
[0043] The following is in conjunction with the appendix Figure 1-11 This application will be described in further detail.
[0044] In one aspect of this disclosure, an LCD bias voltage adjustment circuit is provided, such as... Figure 1 As shown, the LCD bias voltage adjustment circuit includes at least: an LCD bias voltage module, multiple controllable resistor modules, and a control module.
[0045] The LCD bias voltage module is configured to output a bias voltage based on the input voltage; typically, the bias voltage includes AVDD, VGL, VGH, and VCOM.
[0046] Multiple controllable resistor modules are independently connected to the LCD bias voltage module. The controllable resistor modules are configured to change the bias voltage output by the LCD bias voltage module by adjusting their own resistance.
[0047] Specifically, each controllable resistor module is responsible for adjusting a bias voltage. Therefore, when the bias voltage includes AVDD, VGL, VGH and VCOM, there are four controllable resistor modules, which change AVDD, VGL, VGH and VCOM respectively by adjusting their own resistance values.
[0048] The control module is communicatively connected to multiple controllable resistor modules. The control module is configured to issue adjustment commands to one or more controllable resistor modules in response to adjustment requests, so as to adjust the resistance value of the corresponding controllable resistor module and then adjust the corresponding bias voltage. Each controllable resistor module is independent of each other and does not affect each other. Therefore, AVDD, VGL, VGH and VCOM can be adjusted independently, thereby accurately controlling the power-on and power-off sequence.
[0049] The adjustment request can be triggered by the control module itself or by an external input command. Accordingly, the external source should be able to establish communication with the control module to transmit the adjustment command sent to the control module from the external source.
[0050] This embodiment employs the above-described technical solution, utilizing a control module to adjust the resistance value of the controllable resistor module, thereby adjusting the LCD bias voltage. The control module independently adjusts the resistance value of each controllable resistor module, thereby achieving independent adjustment of AVDD, VGH, VGL, and VCOM. This provides a wide adjustment range, high adjustment precision, and can meet the voltage requirements of different LCD color screens. The adjustment is flexible, reliable, convenient, quick, and has good compatibility.
[0051] Specifically, the LCD bias voltage module includes a power management chip, which has output pins, feedback pins, and power input pins, each with a different function.
[0052] Specifically, the output pin is connected to GND via a Schottky diode and / or capacitor. The feedback pin is connected to multiple controllable resistor modules. The power input pin is connected to GND via an NPN transistor and / or capacitor. This allows the LCD bias voltage module to independently adjust AVDD, VGL, VGH, and VCOM under the control of the control module and multiple controllable resistor modules.
[0053] In specific implementation, such as Figure 2 As shown, the power management chip is a 24-pin TPS65105 management chip U1. Its output pins 5 and 6 are connected in parallel and then connected to GND through Schottky diode D1 and capacitor C3. An AVDD output node is established between Schottky diode D1 and capacitor C3.
[0054] like Figure 2 As shown, the output pin 13 of the TPS65105 management chip U1 is connected to GND through capacitor C10, and a VGH output node is established between the output pin 13 and capacitor C10.
[0055] like Figure 2 As shown, the output pin 10 of the TPS65105 management chip U1 is connected to GND through capacitor C13, and a VCOM output node is established between the output pin 10 and capacitor C13.
[0056] like Figure 2 As shown, the output pin 2 of the TPS65105 management chip U1 is connected to GND through capacitor C17, and a VDD output node is established between the output pin 2 and capacitor C17.
[0057] like Figure 2 As shown, the output pin 18 of the TPS65105 management chip U1 is connected to GND via capacitor C9, Schottky diode D2, and capacitor C12 in sequence. A VGL output node is established between Schottky diode D2 and capacitor C12. In addition, capacitor C9 is also connected to Schottky diode D3, which is connected in parallel with Schottky diode D2 and capacitor C12.
[0058] Furthermore, to facilitate connection to the TFT color screen, the LCD bias voltage adjustment circuit also includes an LCD bias voltage output module, which is connected to the LCD bias voltage module and is used to output the bias voltage.
[0059] In specific implementation, such as Figure 3 As shown, the LCD bias voltage output module includes a 6-pin bias voltage output interface LCD-Bias-OUT. Pins 1-5 of the bias voltage output interface LCD-Bias-OUT are connected to the AVDD, VDD, VGH, VGL and VCOM output nodes of the LCD bias voltage module, respectively. Pin 6 of the bias voltage output interface LCD-Bias-OUT is connected to GND.
[0060] When a TFT color screen needs to be connected, simply connect the bias voltage output interface LCD-Bias-OUT to the TFT color screen to provide bias voltage, which is very convenient.
[0061] like Figure 2 As shown, the power input pin 3 of the TPS65105 management chip U1 is connected to GND via NPN transistor Q1 and capacitor C15. The base of NPN transistor Q1 is connected to pin 3, the collector of NPN transistor Q1 is connected to capacitor C15, and the emitter of NPN transistor Q1 is connected to the VDD output node. A 5V input voltage is established between the collector of NPN transistor Q1 and capacitor C15.
[0062] like Figure 2 As shown, the feedback pin 1 of the TPS65105 management chip U1 is connected to the AVDD output node through capacitor C2, and the FB1 input node is established between pin 1 and capacitor C2.
[0063] like Figure 2 As shown, the feedback pin 11 of the TPS65105 management chip U1 is connected to GND through capacitor C7, and a VCOMIN input node is established between the feedback pin 11 and capacitor C7.
[0064] like Figure 2 As shown, the feedback pin 20 of the TPS65105 management chip U1 is connected to GND through capacitor C14, and a REF input node is established between pin 20 and capacitor C14.
[0065] like Figure 2 As shown, the feedback pins 12 and 21 of the TPS65105 management chip U1 are directly connected to the controllable resistor module.
[0066] In addition, such as Figure 2As shown, pin 4 of the TPS65105 management chip U1 is connected to output pins 5 and 6 through inductor L1. Pin 4 is also connected to GND through capacitor C1, and a 5V input voltage is established between pin 4 and capacitor C1.
[0067] like Figure 2 As shown, pins 24 and 23 of the TPS65105 management chip U1 are connected in parallel and then connected to pin 4 through resistor R1.
[0068] like Figure 2 As shown, pin 22 of the TPS65105 management chip U1 is connected to GND via capacitor C5 and resistor R2.
[0069] like Figure 2 As shown, pin 16 of the TPS65105 management chip U1 is connected to pin 17 through capacitor C8.
[0070] like Figure 2 As shown, pins 7, 8, and 19 of the TPS65105 management chip U1 are connected to GND.
[0071] like Figure 2 As shown, pin 14 of the TPS65105 management chip U1 is connected to pin 15 through capacitor C6.
[0072] like Figure 2 As shown, pin 9 of the TPS65105 management chip U1 is connected to the AVDD output node.
[0073] In the embodiments disclosed herein, such as Figure 4 As shown, when the bias voltage includes AVDD, VGL, VGH and VCOM, the four controllable resistor modules each include 16-pin digital potentiometers U2, U3, U4 and U5. The digital potentiometers U2, U3, U4 and U5 are all dual-channel, 256-digit digitally controlled variable resistors that can realize I2C communication. Each digital potentiometer is independently controlled by the control module and does not interfere with each other. The output can be turned off independently, thereby accurately controlling the power-on and power-off sequence.
[0074] Specifically, such as Figure 4 As shown, pins 15 and 3 of digital potentiometer U2 are connected to the FB1 input node of the LCD bias voltage module; pin 2 is connected to the AVDD output node of the LCD bias voltage module; pin 5 is connected to GND through capacitor C4, and a 3.3V input voltage node is established between pin 5 and capacitor C4; pins 6, 7, and 8 are connected to the control module; pins 1, 4, 13, and 14 are left floating; pins 9-12 and 16 are connected to GND.
[0075] Specifically, such as Figure 4As shown, pins 15 and 3 of the digital potentiometer U3 are connected to the feedback pin 21 of the TPS65105 management chip U1; pin 2 is connected to the VGL output node of the LCD bias voltage module; pin 5 is connected to GND through capacitor C11, and a 3.3V input voltage node is established between pin 5 and capacitor C11. The 3.3V input voltage node is connected to pin 9; pins 6, 7, and 8 are connected to the control module; pin 16 is connected to the REF input node of the LCD bias voltage module; pins 1, 4, 13, and 14 are left floating; pins 10-12 are connected to GND.
[0076] Specifically, such as Figure 4 As shown, pins 15 and 3 of the digital potentiometer U4 are connected to the feedback pin 12 of the TPS65105 management chip U1; pin 2 is connected to the VGH output node of the LCD bias voltage module; pin 5 is connected to GND through capacitor C16, and a 3.3V input voltage node is established between pin 5 and capacitor C16. The 3.3V input voltage node is connected to pin 10; pins 6, 7, and 8 are connected to the control module; pins 1, 4, 13, and 14 are left floating; pins 9, 11, 12, and 16 are connected to GND.
[0077] Specifically, such as Figure 4 As shown, pins 15 and 3 of the digital potentiometer U5 are connected to the VCOMIN input node of the LCD bias voltage module; pin 2 is connected to the AVDD output node of the LCD bias voltage module; pin 5 is connected to GND through capacitor C18, and a 3.3V input voltage node is established between pin 5 and capacitor C18. The 3.3V input voltage node is connected to pins 9 and 10; pins 6, 7, and 8 are connected to the control module; pins 1, 4, 13, and 14 are left floating; pins 11, 12, and 16 are connected to GND.
[0078] As can be seen, the LCD bias voltage module inputs a 5V voltage, and by adjusting the resistance values of digital potentiometers U2, U3, U4 and U5, it can output AVDD, VGL, VGH and VCOM voltages respectively.
[0079] In the embodiments disclosed herein, such as Figure 4 and Figure 5 As shown, the control module includes a 16-pin microcontroller U6. When the bias voltage includes AVDD, VGL, VGH, and VCOM, and there are four digital potentiometers U2, U3, U4, and U5, pin 1 of the microcontroller U6 is connected to pin 7 of the four digital potentiometers U2, U3, U4, and U5, thereby establishing the SCL signal line. Pin 2 of the microcontroller U6 is connected to pin 8 of the four digital potentiometers U2, U3, U4, and U5, thereby establishing the SDA signal line. In this way, the microcontroller U6 and the four digital potentiometers U2, U3, U4, and U5 achieve I2C communication through SDA and SCL.
[0080] like Figure 4 and Figure 5 As shown, pin 5 of microcontroller U6 is connected to pin 6 of digital potentiometer U5 as the control signal for VCOM_EN; pin 9 of microcontroller U6 is connected to pin 6 of digital potentiometer U3 as the control signal for VGL_EN; pin 10 of microcontroller U6 is connected to pin 6 of digital potentiometer U4 as the control signal for VGH_EN; and pin 11 of microcontroller U6 is connected to pin 6 of digital potentiometer U2 as the control signal for AVDD_EN. With this design, microcontroller U6 controls the enable pins of the four digital potentiometers U2, U3, U4, and U5 through AVDD_EN, VGH_EN, VGL_EN, and VCOM_EN, thereby individually controlling the output of the bias voltage.
[0081] In addition, such as Figure 5 As shown, pin 1 of microcontroller U6 is connected to the 3.3V input voltage node through resistor R6, and pin 2 of microcontroller U6 is connected to the 3.3V input voltage node through resistor R5.
[0082] like Figure 5 As shown, pin 6 of microcontroller U6 is left floating. Pins 15 and 16 of microcontroller U6 are connected in parallel and then connected to GND through capacitor C19. At the same time, a 3.3V input voltage node is established between the parallel connection point of pins 15 and 16 and capacitor C19. Capacitor C20 is connected in parallel with capacitor C19. Pin 14 of microcontroller U6 is connected to GND.
[0083] In specific implementation, if the adjustment request is generated by an external input instruction to the control module, the specific method for establishing communication between the external party and the control module can be USB communication, in which case the microcontroller U6 is a USB microcontroller.
[0084] Correspondingly, such as Figure 1 As shown, the LCD bias voltage adjustment circuit further includes: a TYPE-C interface module, a USB-to-serial module, and a USB multiplexing module. The TYPE-C interface module is configured to communicate with the adjustment request initiating device, which can be a mobile terminal (such as a mobile phone or other handheld terminal) or a PC. The USB-to-serial module communicates with a USB microcontroller. The USB multiplexing module communicates with the TYPE-C interface module, the USB-to-serial module, and the USB microcontroller to update / download the control program of the USB microcontroller or to enable communication between the adjustment request initiating device and the USB microcontroller. The USB multiplexing module is also communicatively connected to a USB selection interface module to select whether to update / download the control program of the USB microcontroller or to enable communication between the adjustment request initiating device and the USB microcontroller.
[0085] By adopting the above technical solution, the device initiating the adjustment request can communicate and interact with the USB microcontroller through its own USB interface.
[0086] Specifically, such as Figure 6 As shown, the TYPE-C interface module includes a 12-pin TYPE-C interface. Pins 1 and 12 of the TYPE-C interface are connected to GND, pins 2 and 11 are VBUS pins, and a fuse is connected between the VBUS pin and the 5V voltage input node. Pins 3 and 9 are left floating, pin 4 is connected to GND through resistor R7, pin 10 is connected to GND through resistor R9, and pins 5-8 are used to connect to the USB multiplexing module.
[0087] As can be seen, pins 1-6 and pins 7-12 of the TYPE-C interface are symmetrically arranged, thereby enabling reversible insertion and facilitating quick connection and communication between the TYPE-C interface and the USB interface of the device initiating the adjustment request.
[0088] Specifically, such as Figure 7 As shown, the USB-to-serial module includes a 10-pin USB-to-serial chip U8. Pins 8 and 9 of the USB-to-serial chip U8 are connected to pins 8 and 7 of the microcontroller U6. Pins 1 and 2 of the USB-to-serial chip U8 are connected to pins 12 and 13 of the microcontroller U6. Pins 7 and 10 of the USB-to-serial chip U8 are connected in parallel and then connected to GND through capacitor C27. A 3.3V input voltage node is established between the parallel connection point of pins 7 and 10 and capacitor C27. Pin 3 of the USB-to-serial chip U8 is connected to GND, and pins 4, 5, and 6 of the USB-to-serial chip U8 are left floating. This design successfully implements the USB-to-serial function, ensuring that the device initiating the adjustment request communicates with the USB microcontroller through its own USB interface. The device initiating the adjustment request (e.g., a PC) inputs the voltage parameters to be adjusted to the microcontroller U6, thereby controlling the output of the bias voltage.
[0089] Specifically, such as Figure 10 As shown, the USB multiplexing module includes a 10-pin USB multiplexer U9, such as... Figure 11 As shown, the USB selection interface module includes a 3-pin USB selection interface CON1. Pin 2 of the USB selection interface CON1 is connected to pin 2 of the USB multiplexer U9. Pins 3 and 4 of the USB multiplexer U9 are connected to either pins 6 and 5 or pins 8 and 7 of the TYPE-C interface. Pins 8 and 9 of the USB multiplexer U9 are connected to pins 2 and 1 of the USB to serial port chip U8. Pins 6 and 7 of the USB multiplexer U9 are connected to pins 13 and 12 of the microcontroller U6.
[0090] In addition, such as Figure 10 and Figure 11As shown, pin 1 of the USB multiplexer U9 is connected to GND through capacitor C26, and a 5V input voltage node is established between pin 1 and capacitor C26. Pins 5 and 10 of the USB multiplexer U9 are connected to GND, pin 3 of the USB selection interface CON1 is connected to GND, and pin 1 of the USB selection interface CON1 is connected to a 3.3V input voltage node through resistor R10.
[0091] If pins 1 and 2 of the USB selection interface CON1 are connected, the USB signal of the TYPE-C interface is connected to the microcontroller U6 through the USB multiplexer U9. At this time, the device download or update of the control program of the microcontroller U6 can be initiated by adjusting the request. If pins 2 and 3 of the USB selection interface CON1 are connected, the USB signal of the TYPE-C interface is connected to the USB to serial port chip U8 through the USB multiplexer U9. At this time, communication between the adjustment request initiating device and the microcontroller U6 can be realized.
[0092] Furthermore, such as Figure 1 As shown, the control module is communicatively connected to a display module, which is used to display the current bias voltage set value and actual output value in real time, making it intuitive and convenient.
[0093] Specifically, such as Figure 9 As shown, the display module includes an 8-pin OLED display interface. Pins 1, 3, and 4 of the OLED display interface are connected to GND. Pin 2 is connected to GND through capacitor C28. A 3.3V input voltage node is established between pin 2 and capacitor C28. Pins 5 and 7 of the OLED display interface are connected to pins 4 and 3 of the microcontroller U6, respectively. Pin 6 of the OLED display interface is connected to the 3.3V input voltage node. Pin 8 is connected to GND through capacitor C29. Pin 8 is also connected to the 3.3V input voltage node through resistor R11.
[0094] Furthermore, such as Figure 1 As shown, the LCD bias voltage adjustment circuit also includes a power supply regulator module LDO. The power supply regulator module LDO is connected to components such as the controllable resistor module and the control module to provide stable power to the LCD bias voltage adjustment circuit and ensure its continuous normal operation.
[0095] Specifically, the LDO power regulator module includes a 5-pin power regulator U7. Pin 1 of the power regulator U7 is connected to GND through capacitor C21, establishing a 5V input voltage node between pin 1 and capacitor C21. Pin 1 of the power regulator U7 is connected to the first end of capacitor C22 through resistor R8, and the second end of capacitor C22 is connected to GND. Pin 3 of the power regulator U7 is connected to GND. Pin 4 of the power regulator U7 is connected to GND through capacitor C23. Pin 5 of the power regulator U7 is connected to GND through capacitor C25, establishing a 3.3V output voltage node between pin 5 and capacitor C25. In addition, capacitor C24 is connected in parallel with capacitor C25.
[0096] As can be seen, the LDO power supply module converts the 5V voltage input from the TYPE-C interface module to 3.3V, providing stable power to the LCD bias voltage adjustment circuit.
[0097] In another aspect of the present disclosure, an apparatus is provided, including the aforementioned LCD bias voltage adjustment circuit.
[0098] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0099] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. An LCD bias voltage adjustment circuit, characterized in that, include: The LCD bias voltage module is configured to output a bias voltage based on the input voltage; Multiple controllable resistor modules are independently connected to the LCD bias voltage module. The controllable resistor modules are configured to change the bias voltage output by the LCD bias voltage module by adjusting their own resistance. A control module is communicatively connected to multiple controllable resistor modules. The control module is configured to issue adjustment commands to the controllable resistor modules in response to adjustment requests, so as to adjust the resistance value of the controllable resistor modules.
2. The LCD bias voltage adjustment circuit according to claim 1, characterized in that: The bias voltages include AVDD, VGL, VGH, and VCOM; The controllable resistor module has four components, which can change AVDD, VGL, VGH and VCOM by adjusting their own resistance values respectively.
3. The LCD bias voltage adjustment circuit according to claim 2, characterized in that: The LCD bias voltage module includes a power management chip, which has output pins, feedback pins, and power input pins. The output pin is connected to GND via a Schottky diode and / or capacitor. The feedback pin is connected to multiple controllable resistor modules; The power input pin is connected to GND via an NPN transistor and / or a capacitor.
4. The LCD bias voltage adjustment circuit according to claim 1, characterized in that: The controllable resistor module includes a digital potentiometer.
5. The LCD bias voltage adjustment circuit according to claim 1, characterized in that: The control module includes a microcontroller.
6. The LCD bias voltage adjustment circuit according to claim 5, characterized in that: The microcontroller is a USB microcontroller; The LCD bias voltage adjustment circuit further includes: The TYPE-C interface module is configured to communicate with the device that initiated the adjustment request. USB to serial port module, for communication connection with USB microcontroller; The USB multiplexing module is communicatively connected to the TYPE-C interface module, the USB to serial port module, and the USB microcontroller. The USB multiplexing module is also communicatively connected to the USB selection interface module to enable communication between the adjustment request initiating device and the USB microcontroller.
7. The LCD bias voltage adjustment circuit according to claim 1, characterized in that: It also includes an LCD bias voltage output module, which is connected to the LCD bias voltage module.
8. The LCD bias voltage adjustment circuit according to claim 1, characterized in that: The control module is communicatively connected to a display module, which is used to display the current bias voltage set value and actual output value in real time.
9. The LCD bias voltage adjustment circuit according to claim 1, characterized in that: It also includes a power supply regulator module, which is connected to the controllable resistor module and the control module to supply power to the controllable resistor module and the control module.
10. An apparatus, characterized in that: The LCD bias voltage adjustment circuit includes any one of claims 1-9.