Shift register, gate integrated driving circuit and display screen

• US 9,766,741 B2
• Filed: 11/10/2014
• Issued: 09/19/2017
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Original Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Inventors: Zhao, Weijie, Dong, Xue, Wang, Haisheng, Yang, Shengji, Liu, Yingming
• Primary Examiner(s): Johnson, Gerald
• Application Number:
  US14/443,589
• Publication Number:
  US 20160266699A1
• Time in Patent Office: 1,044 Days
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G11C 19/287 Organisation of a multiplicity of shift registers

Abstract

There is disclosed a shift register, a gate integrated driving circuit and a display screen. In the shift register, a connection point between the source of the first thin film transistor (T1) and the drain of the second thin film transistor (T2) is set as the first pulling-up node (PU1), a connection point between the capacitor (C1) and the gate of the third thin film transistor (T3) is set as the second pulling-up node (PU2), and the leakage-proof module is added between the first pulling-up node (PU1) and the second pulling-up node (PU2). The leakage-proof module is configured to, under the control of the display control signal terminal (CTI): conduct the path between the first pulling-up node (PU1) and the second pulling-up node (PU2) during the display period in a frame, so that the shift register can output a normal gate-on signal; and disconnect the path between the first pulling-up node (PU1) and the second pulling-up node (PU2) during the touch period in the frame, which is equivalent to connecting a resistor having a large resistance in a discharging path of the capacitor (C1) in series, so that the discharging of the capacitor (C1) can be slowed greatly, and a leakage speed of the capacitor (C1) is decreased effectively, which avoids a problem of abnormal displaying occurs possibly in an application of a touch screen with a high reporting rate.

Claims

1. A shift register, comprising:

a first thin film transistor having a gate connected with a signal input terminal, a drain connected with a first reference signal terminal, and a source connected with a first pulling-up node;

a second thin film transistor having a gate connected with a reset signal terminal, a drain connected with the first pulling-up node, and a source connected with a second reference signal terminal;

a third thin film transistor having a gate connected with the second pulling-up node, a drain connected with a clock signal terminal, and a source connected with a signal output terminal;

a fourth thin film transistor having a gate connected with a touch control signal terminal, a drain connected with the signal output terminal, a source connected with a low voltage signal terminal, wherein the touch control signal terminal is configured to turn on the fourth thin film transistor during a touch period and turn off the fourth thin film transistor during a display period;

a capacitor, provided between the second pulling-up node and the signal output terminal; and

a leakage-proof module, provided among a display control signal terminal, the first pulling-up node and the second pulling-up node, wherein the leakage-proof module is configured to, under a control of the display control signal terminal, conduct a path between the first pulling-up node and the second pulling-up node during the display period and disconnect the path between the first pulling-up node and the second pulling-up node during the touch period.

3. The shift register of claim 1, wherein all of the thin film transistors included in the shift register are N-type thin film transistors;

the display control signal terminal supplies a high level signal while the touch control signal terminal supplies a low level signal, during the display period; and

the display control signal terminal supplies a low level signal while the touch control signal terminal supplies a high level signal, during the touch period.

4. The shift register of claim 3, wherein in a case in which a forward scan is activated, the first reference signal terminal supplies a high level signal while the second reference signal terminal supplies a low level signal, during the display period;

and

the first reference signal terminal and the second reference signal terminal supply high level signals at the same time, during the touch period.

5. The shift register of claim 3, wherein in a case in which a reverse scan is activated, the first reference signal terminal supplies a low level signal while the second reference signal terminal supplies a high level signal, during the display period;

and

the first reference signal terminal and the second reference signal terminal supply high level signals at the same time during the touch period.

6. The shift register of claim 1, further comprising a pulling-down module, provided among the display control signal terminal, the first pulling-up node, the second pulling-up node, the signal output terminal and the low voltage signal terminal, configured to maintain the first pulling-up node, the second pulling-up node and the signal output terminal at a low level during a non-operational period of the shift register.

7. The shift register of claim 6, wherein the pulling-down module comprises:

a sixth thin film transistor having a drain connected with the display control signal terminal, and a source connected with a pulling-down node;

a seventh thin film transistor having a drain connected with the pulling-down node, the gate connected with the second pulling-up node, and a source connected with the low voltage signal terminal;

an eighth thin film transistor having a gate and a drain connected with the display control signal terminal, and a source connected with a gate of the sixth thin film transistor;

a ninth thin film transistor having a drain connected with the source of the eighth thin film transistor, a gate connected with the second pulling-up node, and a source connected with the low voltage signal terminal;

a tenth thin film transistor having a drain connected with the first pulling-up node, a gate connected with the pulling-down node, and a source connected with the low voltage signal terminal; and

an eleventh thin film transistor having a drain connected with the signal output terminal, a gate connected with the pulling-down node; and

a source connected with the low voltage signal terminal.

8. A gate integrated driving circuit comprising a plurality of stages of the shift register of claim 1 connected in cascade;

wherein

except for a first stage of shift register and a last stage of shift register, each stage of shift register is configured to output a trigger signal to a signal input terminal of a next stage of shift register adjacent thereto, and to output a reset signal to a reset signal terminal of a previous stage of shift register adjacent thereto;

the first stage of shift register is configured to output a trigger signal to the signal input terminal of a second stage of shift register; and

the last stage of shift register is configured to output the reset signal to its own reset signal terminal and the reset signal terminal of its previous stage of shift register.

9. A display screen comprising the gate integrated driving circuit of claim 8.

10. The gate integrated driving circuit of claim 8, wherein the leakage-proof module comprises a fifth thin film transistor having a gate connected with the display control signal terminal, a drain connected with the first pulling-up node and a source connected with the second pulling-up node.

11. The gate integrated driving circuit of claim 8, wherein all of the thin film transistors included in the shift register are N-type thin film transistors;

the display control signal terminal supplies a high level signal while the touch control signal terminal supplies a low level signal, during the display period; and

the display control signal terminal supplies a low level signal while the touch control signal terminal supplies a high level signal, during the touch period.

12. The gate integrated driving circuit of claim 11, wherein in a case in which a forward scan is activated, the first reference signal terminal supplies a high level signal while the second reference signal terminal supplies a low level signal, during the display period;

and

the first reference signal terminal and the second reference signal terminal supply high level signals at the same time, during the touch period.

13. The gate integrated driving circuit of claim 11, wherein in a case in which a reverse scan is activated, the first reference signal terminal supplies a low level signal while the second reference signal terminal supplies a high level signal, during the display period;

and

the first reference signal terminal and the second reference signal terminal supply high level signals at the same time during the touch period.

14. The gate integrated driving circuit of claim 8, wherein each stage of shift register further comprises a pulling-down module, provided among the display control signal terminal, the first pulling-up node, the second pulling-up node, the signal output terminal and the low voltage signal terminal, configured to maintain the first pulling-up node, the second pulling-up node and the signal output terminal at a low level during a non-operational period of the stage of shift register.

15. The gate integrated driving circuit of claim 14, wherein the pulling-down module comprises:

a sixth thin film transistor having a drain connected with the display control signal terminal, and a source connected with a pulling-down node;

a seventh thin film transistor having a drain connected with the pulling-down node, the gate connected with the second pulling-up node, and a source connected with the low voltage signal terminal;

an eighth thin film transistor having a gate and a drain connected with the display control signal terminal, and a source connected with a gate of the sixth thin film transistor;

a ninth thin film transistor having a drain connected with the source of the eighth thin film transistor, a gate connected with the second pulling-up node, and a source connected with the low voltage signal terminal;

a tenth thin film transistor having a drain connected with the first pulling-up node, a gate connected with the pulling-down node, and a source connected with the low voltage signal terminal; and

an eleventh thin film transistor having a drain connected with the signal output terminal, a gate connected with the pulling-down node; and

a source connected with the low voltage signal terminal.

16. The display screen of claim 9, wherein the leakage-proof module comprises a fifth thin film transistor having a gate connected with the display control signal terminal, a drain connected with the first pulling-up node and a source connected with the second pulling-up node.

17. The display screen of claim 9, wherein each stage of shift register further comprises a pulling-down module, provided among the display control signal terminal, the first pulling-up node, the second pulling-up node, the signal output terminal and the low voltage signal terminal, configured to maintain the first pulling-up node, the second pulling-up node and the signal output terminal at a low level during a non-operational period of the stage of shift register.

18. The display screen of claim 17, wherein the pulling-down module comprises:

a sixth thin film transistor having a drain connected with the display control signal terminal, and a source connected with a pulling-down node;

a seventh thin film transistor having a drain connected with the pulling-down node, the gate connected with the second pulling-up node, and a source connected with the low voltage signal terminal;

an eighth thin film transistor having a gate and a drain connected with the display control signal terminal, and a source connected with a gate of the sixth thin film transistor;

a ninth thin film transistor having a drain connected with the source of the eighth thin film transistor, a gate connected with the second pulling-up node, and a source connected with the low voltage signal terminal;

a tenth thin film transistor having a drain connected with the first pulling-up node, a gate connected with the pulling-down node, and a source connected with the low voltage signal terminal; and

an eleventh thin film transistor having a drain connected with the signal output terminal, a gate connected with the pulling-down node; and

a source connected with the low voltage signal terminal.

2. The shift register of claim wherein the leakage-proof module comprises a fifth thin film transistor having a gate connected with the display control signal terminal, a drain connected with the first pulling-up node and a source connected with the second pulling-up node.