CIRCUIT AND METHOD FOR COMMON VOLTAGE FEEDBACK COMPENSATION AND LIQUID CRYSTAL DISPLAY DEVICE

• US 20210118383A1
• Filed: 09/29/2018
• Published: 04/22/2021
• Est. Priority Date: 07/17/2018
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
• Original Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
• Inventors: Zhang, Xianming
• Granted Patent: US 11,062,665 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2310/0291 Details of output amplifiers or buffers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0214 with crosstalk due to leakage current of pixel switch in active matrix panels
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/025 Reduction of instantaneous peaks of current
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

The invention provides a circuit and method for common voltage feedback compensation and LCD. The circuit comprises: a timing controller and a power management circuit, the timing controller and the power management circuit being electrically connected; the timing controller providing a corresponding preset feedback compensation value to the power management circuit under different images; the power management circuit comprising a common voltage compensation circuit and an adder, and the adder integrating the feedback compensation value and a feedback common voltage returned from a feedback point in a display panel through addition obtain an integration result, the common voltage compensation circuit obtaining a common voltage compensation signal based on the integration result and providing the common voltage compensation signal to the display panel. The invention generates the feedback compensation value required for the common voltage feedback and provides to the power management circuit under different images through the timing controller.

Claims

1. A circuit for common voltage feedback compensation, comprising:

a timing controller and a power management circuit, the timing controller and the power management circuit being electrically connected;

the timing controller providing a corresponding preset feedback compensation value to the power management circuit under different images;

the power management circuit comprising a common voltage compensation circuit and an adder, and the adder integrating the feedback compensation value and a feedback common voltage returned from a feedback point in a display panel through addition obtain an integration result, the common voltage compensation circuit obtaining a common voltage compensation signal based on the integration result and providing the common voltage compensation signal to the display panel.

2. The circuit for common voltage feedback compensation as claimed in claim 1, wherein the feedback compensation value is pre-stored in a flash memory.

3. The circuit for common voltage feedback compensation as claimed in claim 1, wherein the timing controller provides, only under a crosstalk image, the corresponding feedback compensation value to the power management circuit for the crosstalk image.

4. The circuit for common voltage feedback compensation as claimed in claim 3, wherein the timing controller provides a GND signal as the feedback compensation value to the power management circuit under non-crosstalk images.

5. The circuit for common voltage feedback compensation as claimed in claim 1, wherein the adder comprises a first input end, a second input end, and an output end, the first input end inputs the feedback compensation value, the second input end inputs the feedback common voltage, and the output end outputs the addition integration result of the feedback compensation value and the feedback common voltage.

6. The circuit for common voltage feedback compensation as claimed in claim 1, wherein the common voltage compensation circuit comprises:

a capacitor having one end connected to the output end of the adder and the other end connected to one end of a first resistor;

the first resistor having the other end connected to an inverting input terminal of an operational amplifier;

a second resistor having one end connected to the inverting input terminal of the operational amplifier and the other end connected to an output terminal of the operational amplifier;

the operational amplifier having a non-inverting input terminal inputting a reference common voltage, and the output terminal outputting a common voltage compensation signal.

7. A liquid crystal display (LCD) device, comprising a circuit for common voltage feedback compensation, the circuit for common voltage feedback compensation comprising:

a timing controller and a power management circuit, the timing controller and the power management circuit being electrically connected;

the timing controller providing a corresponding preset feedback compensation value to the power management circuit under different images;

the power management circuit comprising a common voltage compensation circuit and an adder, and the adder integrating the feedback compensation value and a feedback common voltage returned from a feedback point in a display panel through addition obtain an integration result, the common voltage compensation circuit obtaining a common voltage compensation signal based on the integration result and providing the common voltage compensation signal to the display panel.

8. The LCD device as claimed in claim 7, wherein the feedback compensation value is pre-stored in a flash memory.

9. The LCD device as claimed in claim 7, wherein the timing controller provides, only under a crosstalk image, the corresponding feedback compensation value to the power management circuit for the crosstalk image.

10. The LCD device as claimed in claim 9, wherein the timing controller provides a GND signal as the feedback compensation value to the power management circuit under non-crosstalk images.

11. The LCD device as claimed in claim 7, wherein the adder comprises a first input end, a second input end, and an output end, the first input end inputs the feedback compensation value, the second input end inputs the feedback common voltage, and the output end outputs the addition integration result of the feedback compensation value and the feedback common voltage.

12. The LCD device as claimed in claim 7, wherein the common voltage compensation circuit comprises:

a capacitor having one end connected to the output end of the adder and the other end connected to one end of a first resistor;

the first resistor having the other end connected to an inverting input terminal of an operational amplifier;

a second resistor having one end connected to the inverting input terminal of the operational amplifier and the other end connected to an output terminal of the operational amplifier;

the operational amplifier having a non-inverting input terminal inputting a reference common voltage, and the output terminal outputting a common voltage compensation signal.

13. A method for common voltage feedback compensation, comprising:

a timing controller providing a corresponding preset feedback compensation value to a power management circuit under different images;

the power management circuit comprising a common voltage compensation circuit and an adder, and the adder integrating the feedback compensation value and a feedback common voltage returned from a feedback point in a display panel through addition obtain an integration result, the common voltage compensation circuit obtaining a common voltage compensation signal based on the integration result and providing the common voltage compensation signal to the display panel.

14. The method for common voltage feedback compensation as claimed in claim 13, wherein the timing controller provides, only under a crosstalk image, the corresponding feedback compensation value to the power management circuit for the crosstalk image.

15. The method for common voltage feedback compensation as claimed in claim 14, wherein the timing controller provides a GND signal as the feedback compensation value to the power management circuit under non-crosstalk images.