Gate driving circuit

• US 10,460,689 B2
• Filed: 12/20/2016
• Issued: 10/29/2019
• Est. Priority Date: 08/31/2016
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Original Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Inventors: Shi, Longqiang
• Primary Examiner(s): Shen, Yuzhen
• Application Number:
  US15/327,315
• Publication Number:
  US 20190156775A1
• Time in Patent Office: 1,043 Days
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/0264 Details of driving circuits
• CPC Class Codes: G09G 2310/0286 Details of a shift registers 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 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 3/3677 suitable for active matrices only

Abstract

Disclosed is a gate driving circuit, which includes multi-stages of gate driving units. Each stage of gate driving unit includes an input control module, an output control module, a pull-down module, a pull-down maintenance module, and a compensation module. Since the compensation module is provided, a threshold voltage of a transistor will not influence an electric potential of a first node. Hence, a stability of the gate driving circuit can be greatly improved, and a display effect of a liquid crystal display panel can be improved.

Claims

1. A gate driving circuit, comprising multi-stages of gate driving units in series connection with one another,

wherein each stage of gate driving unit is configured to output a scanning signal through an output end thereof according to a scanning signal output by a previous stage of gate driving unit, a scanning signal output by a next stage of gate driving unit, and a clock signal;

and

wherein each stage of gate driving unit comprises;

an input control module, configured to be controlled by the scanning signal output by the previous stage of gate driving unit so as to control an electric potential of a first node;

an output control module, connected to the first node, and configured to control an electric potential of an output end of a present stage of gate driving unit according to the electric potential of the first node;

a pull-down module, connected to the output control module, and configured to pull down the electric potential of the output end of the present stage of gate driving unit according to an electric potential of a second node;

a pull-down maintenance module, connected to the pull-down module, and configured to maintain the electric potential of the second node during a non-scanning period so that the electric potential of the output end of the present stage of gate driving unit is maintained in a negative electric potential; and

a compensation module, connected to the pull-down maintenance module and the first node, and configured to maintain the electric potential of the first node in a negative electric potential during the non-scanning period.

2. The gate driving circuit according to claim 1, wherein the input control module comprises an eleventh transistor;

and

wherein a gate of the eleventh transistor is connected to a constant high voltage output end, a drain thereof is connected to the output end of the previous stage of gate driving unit, and a source thereof is connected to the first node.

3. The gate driving circuit according to claim 2, wherein the output control module comprises:

a twenty-first transistor, with a gate thereof being connected to the first node, a drain thereof being connected to an output end of the clock signal, and a source thereof being connected to the output end of the present stage of gate driving unit;

a twenty-second transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the output end of the clock signal, and a source thereof being connected to a driving output end of the present stage of gate driving unit; and

a bootstrap capacitor, wherein the first node is connected to the output end of the present stage of gate driving unit through the bootstrap capacitor.

4. The gate driving circuit according to claim 3, wherein the pull-down module comprises a fortieth transistor and a forty-first transistor,

wherein a gate and a drain of the fortieth transistor are both connected to the first node, and a source thereof is connected to a drain of the forty-first transistor;

and

wherein a gate of the forty-first transistor is connected to an output end of the next stage of gate driving unit, and a source thereof is connected to the output end of the present stage of gate driving unit.

5. The gate driving circuit according to claim 1, wherein the pull-down maintenance module comprises:

a fifty-first transistor, with a gate and a drain thereof both being connected to a constant high voltage output end, and a source thereof being connected to a fourth node;

a fifty-second transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the fourth node, and a source thereof being connected to a first negative electric potential output end;

a fifty-third transistor, with a gate thereof being connected to the fourth node, a drain thereof being connected to the constant high voltage output end, and a source thereof being connected to the second node;

a fifty-fourth transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the second node, and a source thereof being connected to a third node;

a seventy-third transistor, with a gate thereof being connected to the fourth node, a drain thereof being connected to the constant high voltage output end, and a source thereof being connected to the third node;

a seventy-fourth transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the third node, and a source thereof being connected to a constant low voltage output end;

an eighty-first transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the constant high voltage output end, and a source thereof being connected to a fifth node;

an eighty-second transistor, with a gate thereof being connected to the second node, a drain thereof being connected to the constant low voltage output end, and a source thereof being connected to the fifth node;

a forty-second transistor, with a gate thereof being connected to the compensation module, a drain thereof being connected to the first node, and a source thereof being connected to the fifth node; and

a thirty-second transistor, with a gate thereof being connected to the second node, a drain thereof being connected to the output end of the present stage of gate driving unit, and a source thereof being connected to the first negative electric potential output end,

wherein an electric potential of the constant low voltage output end is lower than an electric potential of the first negative electric potential output end.

6. The gate driving circuit according to claim 5, wherein the input control module comprises an eleventh transistor;

and

wherein a gate of the eleventh transistor is connected to the constant high voltage output end, a drain thereof is connected to the output end of the previous stage of gate driving unit, and a source thereof is connected to the first node.

7. The gate driving circuit according to claim 6, wherein the output control module comprises:

a twenty-first transistor, with a gate thereof being connected to the first node, a drain thereof being connected to an output end of the clock signal, and a source thereof being connected to the output end of the present stage of gate driving unit;

a twenty-second transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the output end of the clock signal, and a source thereof being connected to a driving output end of the present stage of gate driving unit; and

a bootstrap capacitor, wherein the first node is connected to the output end of the present stage of gate driving unit through the bootstrap capacitor.

8. The gate driving circuit according to claim 7, wherein the pull-down module comprises a fortieth transistor and a forty-first transistor,

wherein a gate and a drain of the fortieth transistor are both connected to the first node, and a source thereof is connected to a drain of the forty-first transistor;

and

wherein a gate of the forty-first transistor is connected to an output end of the next stage of gate driving unit, and a source thereof is connected to the output end of the present stage of gate driving unit.

9. The gate driving circuit according to claim 5, wherein an electric potential of the constant high voltage output end is in a range from 20 to 30V;

and

wherein the electric potential of the constant low voltage output end and the electric potential of the first negative electric potential output end are both in a range from −

5 to −

8V.

10. The gate driving circuit according to claim 9, wherein the input control module comprises an eleventh transistor;

and

wherein a gate of the eleventh transistor is connected to the constant high voltage output end, a drain thereof is connected to the output end of the previous stage of gate driving unit, and a source thereof is connected to the first node.

11. The gate driving circuit according to claim 10, wherein the output control module comprises:

a twenty-first transistor, with a gate thereof being connected to the first node, a drain thereof being connected to an output end of the clock signal, and a source thereof being connected to the output end of the present stage of gate driving unit;

a twenty-second transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the output end of the clock signal, and a source thereof being connected to a driving output end of the present stage of gate driving unit; and

a bootstrap capacitor, wherein the first node is connected to the output end of the present stage of gate driving unit through the bootstrap capacitor.

12. The gate driving circuit according to claim 11, wherein the pull-down module comprises a fortieth transistor and a forty-first transistor,

wherein a gate and a drain of the fortieth transistor are both connected to the first node, and a source thereof is connected to a drain of the forty-first transistor;

and

wherein a gate of the forty-first transistor is connected to an output end of the next stage of gate driving unit, and a source thereof is connected to the output end of the present stage of gate driving unit.

13. The gate driving circuit according to claim 5, wherein the compensation module comprises:

a first transistor, with a gate thereof being connected to the output end of the present stage of gate driving unit, a drain thereof being connected to an output end of a positive electric potential, and a source thereof being connected to the gate of the forty-second transistor;

a second transistor, with a gate thereof being connected to the second node, a drain thereof being connected to the gate of the forty-second transistor, and a source thereof being connected to the sixth node;

a third transistor, with a gate and a source thereof being connected to the output end of the present stage of gate driving unit, and a drain thereof being connected to the sixth node;

a storage capacitor; and

a fourth transistor, with a gate thereof being connected to the second node, a drain thereof being connected to the sixth node through the storage capacitor, and a source thereof being connected to a second negative electric potential output end,

wherein the electric potential of the constant low voltage output end, the electric potential of the first negative electric potential output end, and an electric potential of the second negative electric potential output end increase in sequence; and

wherein the electric potential of the constant high voltage output end is higher than an electric potential of the positive electric potential output end.

14. The gate driving circuit according to claim 13, wherein the input control module comprises an eleventh transistor;

and

wherein a gate of the eleventh transistor is connected to the constant high voltage output end, a drain thereof is connected to the output end of the previous stage of gate driving unit, and a source thereof is connected to the first node.

15. The gate driving circuit according to claim 14, wherein the output control module comprises:

a twenty-first transistor, with a gate thereof being connected to the first node, a drain thereof being connected to an output end of the clock signal, and a source thereof being connected to the output end of the present stage of gate driving unit;

a twenty-second transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the output end of the clock signal, and a source thereof being connected to a driving output end of the present stage of gate driving unit; and

a bootstrap capacitor, wherein the first node is connected to the output end of the present stage of gate driving unit through the bootstrap capacitor.

16. The gate driving circuit according to claim 15, wherein the pull-down module comprises a fortieth transistor and a forty-first transistor,

wherein a gate and a drain of the fortieth transistor are both connected to the first node, and a source thereof is connected to a drain of the forty-first transistor;

and

wherein a gate of the forty-first transistor is connected to an output end of the next stage of gate driving unit, and a source thereof is connected to the output end of the present stage of gate driving unit.

17. The gate driving circuit according to claim 13, wherein the electric potential of the positive electric potential output end is in a range from 2 to 5V.

18. The gate driving circuit according to claim 17, wherein the input control module comprises an eleventh transistor;

and

wherein a gate of the eleventh transistor is connected to the constant high voltage output end, a drain thereof is connected to the output end of the previous stage of gate driving unit, and a source thereof is connected to the first node.

19. The gate driving circuit according to claim 18, wherein the output control module comprises:

a twenty-first transistor, with a gate thereof being connected to the first node, a drain thereof being connected to an output end of the clock signal, and a source thereof being connected to the output end of the present stage of gate driving unit;

a twenty-second transistor, with a gate thereof being connected to the first node, a drain thereof being connected to the output end of the clock signal, and a source thereof being connected to a driving output end of the present stage of gate driving unit; and

a bootstrap capacitor, wherein the first node is connected to the output end of the present stage of gate driving unit through the bootstrap capacitor.

20. The gate driving circuit according to claim 19, wherein the pull-down module comprises a fortieth transistor and a forty-first transistor,

wherein a gate and a drain of the fortieth transistor are both connected to the first node, and a source thereof is connected to a drain of the forty-first transistor;

and

wherein a gate of the forty-first transistor is connected to an output end of the next stage of gate driving unit, and a source thereof is connected to the output end of the present stage of gate driving unit.