TOUCH SENSING CIRCUIT AND CONTROL METHOD THEREOF

• US 20170052629A1
• Filed: 06/08/2016
• Published: 02/23/2017
• Est. Priority Date: 08/17/2015
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: LIN, Wu-Wei, Lo, Jui-Chi
• Granted Patent: US 10,198,114 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

A touch sensing circuit and its control method is disclosed herein. The touch sensing circuit includes a plurality of detecting units. The detecting units are arranged in an array, in which each detecting unit includes a sensing pad, a first switch and a second switch. The first switch is configured to selectively conduct the sensing pad and one of a plurality of signal lines. The second switch is configured to selectively conduct two adjacent sensing pads. When the first switches in a first row in the array are on, the sensing pads in the first row are configured to output detecting signals to the signal lines according to a driving signal, and the second switches in a second row adjacent to the first row are on to conduct the sensing pads in the second row to receive and transmit the driving signal together.

Claims

1. A touch sensing circuit, comprising:

a plurality of detecting units arranged in an array, wherein each detecting unit includes;

a sensing pad,

a first switch configured to selectively conduct the sensing pad and one of a plurality of signal lines; and

a second switch configured to selectively conduct two adjacent sensing pads;

wherein when the first switches in a first row in the array are turned on, the sensing pads in the first row are configured to output a plurality of detecting signals to the signal lines according to a driving signal, and the second switches in a second row adjacent to the first row are turned on to conduct the sensing pads in the second row to receive the driving signal together.

2. The touch sensing circuit of claim 1, wherein when the first switches in the first row are turned on, the second switches in the second row are configured to conduct the sensing pads, and the sensing pads in a third row adjacent to the second row are configured to receive a shielding signal having a fixed voltage level.

3. The touch sensing circuit of claim 2, further comprising:

a driving selecting circuit configured to output the driving signal to the sensing pads in the second row and output the shielding signal to the sensing pads in the third row.

4. The touch sensing circuit of claim 3, wherein the driving selecting circuit is configured to receive a scanning signal, and output the driving signal and the shielding signal according to the scanning signal and a plurality of trigger signals corresponding to the rows in the array.

5. The touch sensing circuit of claim 1, wherein the second switch of the detecting unit is configured to be off when the first switch of the detecting unit is on;

and

the second switch of the detecting unit is configured to be on when the first switch of the detecting unit is off.

6. The touch sensing circuit of claim 1, further comprising:

a control circuit configured to output a plurality of control signals to control the first switches and the second switches of the array to be on or off.

7. The touch sensing circuit of claim 6, wherein any one of the first switches of the detecting unit comprises:

a first terminal electrically coupled to the corresponding sensing pad;

a second terminal electrically coupled to the corresponding signal line; and

a control terminal electrically coupled to the control circuit and configured to receive the corresponding control signal.

8. The touch sensing circuit of claim 1, wherein the sensing pads in a fourth row in the array are configured to receive the driving signal when the sensing pads in the second row receive the driving signal.

9. A touch sensing circuit, comprising:

a plurality of first sensing pads; and

a plurality of second sensing pads;

wherein in a first operating stage, the first sensing pads are conducted to a plurality of signal lines correspondingly, and the second sensing pads are conducted to each other and configured to receive a driving signal such that the first sensing pads are configured to output a plurality of detecting signals to corresponding signal lines according to the driving signal.

10. The touch sensing circuit of claim 9, further comprising:

a plurality of third sensing pads;

wherein in a second operating stage, the second sensing pads are conducted to the signal lines correspondingly, and the third sensing pads are conducted to each other and configured to receive the driving signal such that the second sensing pads are configured to output the detecting signals to corresponding signal lines according to the driving signal.

11. The touch sensing circuit of claim 10, wherein in the first operating stage, the third sensing pads are conducted to each other and configured to receive a shielding signal to reduce the interference between the driving signal and the detecting signals.

12. The touch sensing circuit of claim 10, further comprising:

a control circuit configured to output a plurality of control signals to control the touch sensing circuit operates in the first operating stage or the second operating stage.

13. The touch sensing circuit of claim 9, further comprising:

a plurality of first switches electrically coupled between the corresponding first sensing pad and the corresponding signal line; and

a plurality of second switches configured to conduct the adjacent second sensing pads.

14. The touch sensing circuit of claim 13, further comprising:

a control circuit configured to output a plurality of control signals;

wherein any one of the first switches comprises;

a first terminal electrically coupled to the corresponding first sensing pad;

a second terminal electrically coupled to the corresponding signal line; and

a control terminal electrically coupled to the control circuit and configured to receive the corresponding control signal.

15. The touch sensing circuit of claim 14, wherein any one of the second switches comprises:

a first terminal electrically coupled to the corresponding first sensing pad;

a second terminal electrically coupled to the corresponding second sensing pad; and

a control terminal electrically coupled to the control circuit and configured to receive the corresponding control signal.

16. The touch sensing circuit of claim 9, wherein a plurality of fourth sensing pads are configured to receive and transmit the driving signal together when the second sensing pads receive and transmit the driving signal together, wherein the fourth sensing pads and the second sensing pads are arranged in different rows.

17. A control method of a touch sensing circuit, wherein the touch sensing circuit comprises a plurality of signal lines, a plurality of first sensing pads, and a plurality of second sensing pads, and the control method comprises:

in a first operating stage, conducting the first sensing pads to the corresponding signal lines;

conducting the second sensing pads to each other;

providing a driving signal to the second sensing pads; and

reading, from the signal lines, a plurality of detecting signals outputted by the first sensing pads according to the driving signal.

18. The control method of claim 17, wherein the touch sensing circuit further comprises a plurality of third sensing pads, and the control method further comprises:

in a second operating stage, conducting the second sensing pads to the corresponding signal lines;

conducting the third sensing pads to each other;

providing the driving signal to the third sensing pads; and

reading, from the signal lines, the detecting signals outputted by the second sensing pads according to the driving signal.

19. The control method of claim 18, further comprising:

in the first operating stage, conducting the third sensing pads to each other; and

providing a shielding signal to the third sensing pads to reduce the interference between the driving signal and the detecting signals.

20. The control method of claim 17, wherein the touch sensing circuit further comprises a plurality of fourth sensing pads, and the control method further comprises:

in the first operating stage, conducting the fourth sensing pads to each other; and

providing the driving signal to the fourth sensing pads, wherein the fourth sensing pads and the second sensing pads are arranged in different rows.