DIGITAL CAPACITIVE TOUCH SCREEN

• US 20110210944A1
• Filed: 05/12/2011
• Published: 09/01/2011
• Est. Priority Date: 05/11/2009
• Status: Abandoned Application

• Current Assignee: Inferpoint Systems Limited
• Original Assignee: Inferpoint Systems Limited
• Inventors: LIU, Haiping, CHEN, Meiying, CHEN, Qiliang
• Application Number:
  US13/105,906
• Publication Number:
  US 20110210944A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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

Abstract

In the field of touch screens and more particularly capacitive touch screens, a digital capacitive touch screen is provided, which includes a touch substrate and a touch system circuit. The touch system circuit has a touch excitation source and a touch signal detection unit. At least two staggered electrode groups are disposed on the touch substrate, and multiple electrode lines of the electrode groups are connected to the touch excitation source. In a working period of the touch system circuit, for at least one moment, the touch excitation source applies touch signals to more than two electrode lines at the same time, and the touch signal detection unit detects the change of the touch signal on at least one of the electrode lines. Thereby, a high-definition and large-sized digital capacitive touch screen is obtained. The digital capacitive touch screen has a simple structure, low cost, and high reliability.

Claims

1. A digital capacitive touch screen, comprising a touch substrate and a touch system circuit, the touch system circuit having a touch excitation source and a touch signal detection unit, wherein

at least two staggered electrode groups are disposed on the touch substrate, and multiple electrode lines of the electrode groups are connected to the touch system circuit;

in a working period of the touch system circuit, for at least one moment, the touch excitation source applies touch signals to more than two electrode lines at the same time, and the touch signal detection unit selects at least one shielded electrode line as a detecting line;

the detecting line detects the change of the touch signal flowing through the electrode when the touch signal is applied to the electrode; and

the shielded electrode is the electrode where adjacent or non-adjacent electrode lines on two sides of the electrode line are applied with the touch signals, or the electrode where the electrode lines staggered with the electrode line are applied with the touch signals.

2. The digital capacitive touch screen according to claim 1, wherein

a part of the electrode lines are selected as the detecting lines at each moment, the non-detecting lines are also applied with the touch signals when the detecting lines are applied with the touch signals and the changes of the touch signals on the detecting lines are detected;

and the non-detecting lines applied with the touch signals are all of or a part of the non-detecting lines among the electrode lines connected to the touch system circuit except for the detecting lines.

3. The digital capacitive touch screen according to claim 1, wherein

when the detecting lines are applied with the touch signals and the changes of the touch signals flowing through the detecting lines are detected, the other electrodes staggered with the detecting lines are also applied with the touch signals;

and the other electrodes staggered with the detecting lines are all of or a part of the electrodes staggered with the detecting lines.

4. The digital capacitive touch screen according to claim 1, wherein

when the detecting lines are applied with the touch signals and the changes of the touch signals flowing through the detecting lines are detected, the other electrodes not staggered with the detecting lines are also applied with the touch signals;

and the other electrodes not staggered with the detecting lines are all of or a part of the electrodes not staggered with the detecting lines.

5. The digital capacitive touch screen according to claim 1, wherein

when the detecting lines are applied with the touch signals and the changes of the touch signals flowing through the detecting lines are detected, the other electrodes staggered or not staggered with the detecting lines are also applied with the touch signals;

and the other electrodes staggered or not staggered with the detecting lines are all of or a part of the electrodes staggered or not staggered with the detecting lines.

6. The digital capacitive touch screen according to claim 1, wherein

the touch signals output by the touch system circuit to the electrode lines are alternating current (AC) signals having frequencies not smaller than 50 KHz, including AC signals with zero amplitude.

7. The digital capacitive touch screen according to claim 2, wherein

the touch signals output by the touch system circuit to the electrode lines are alternating current (AC) signals having frequencies not smaller than 50 KHz, including AC signals with zero amplitude.

8. The digital capacitive touch screen according to claim 1, wherein

the touch signals applied on the electrodes have the same amplitude, phase, frequency, or serial number, or vary in at least one of the amplitude, phase, frequency, and serial number.

9. The digital capacitive touch screen according to claim 1, wherein

when selecting the detecting lines, the touch system circuit selects a part of the display screen electrode lines as a detecting line group at a moment, and detects the changes of the touch signals flowing through the detecting lines;

or selects two or more parts of the electrode lines as two or more detecting line groups at the same moment, and respectively detects the changes of the touch signals flowing through the detecting line groups.

10. The digital capacitive touch screen according to claim 1, wherein

each detecting line group is formed by one or more electrode lines.

11. The digital capacitive touch screen according to claim 8, wherein

each detecting line group is formed by one or more electrode lines.

12. The digital capacitive touch screen according to claim 1, wherein

the touch system circuit selects the detecting lines in a scanning manner, so as to select different parts of the electrode lines as the detecting lines at different moments.

13. The digital capacitive touch screen according to claim 8, wherein

the touch system circuit selects the detecting lines in a scanning manner, so as to select different parts of the electrode lines as the detecting lines at different moments.

14. The digital capacitive touch screen according to claim 1, wherein

the touch system circuit detects at least one of amplitude, time, phase, frequency signal, and pulse number in the detection of the touch signals on the electrode lines.

15. The digital capacitive touch screen according to claim 1, wherein

the touch system circuit determines the touched electrode lines by detecting the touch signals or detecting differences between variances of the touch signals or variation rates of the touch signals on the electrode lines.

16. The digital capacitive touch screen according to claim 1, wherein

the touch system circuit computes and determines the touched positions among the electrode lines by detecting the touch signals or detecting differences between variances of the touch signals or variation rates of the touch signals on the electrode lines.

17. The digital capacitive touch screen according to claim 12, wherein

the positions where the touch signals are detected or it is detected that the variances of the touch signals or the variation rates of the touch signals are maximum are determined as the touched positions, the positions where the touch signals are detected or it is detected that the variances of the touch signals or the variation rates of the touch signals exceed a preset threshold are determined as the touched positions, or the positions where the touch signals are detected or it is detected that the variances of the touch signals or the variation rates of the touch signals are maximum and exceed a preset threshold are determined as the touched positions.

18. The digital capacitive touch screen according to claim 13, wherein

the positions where the touch signals are detected or it is detected that the variances of the touch signals or the variation rates of the touch signals are maximum are determined as the touched positions, the positions where the touch signals are detected or it is detected that the variances of the touch signals or the variation rates of the touch signals exceed a preset threshold are determined as the touched positions, or the positions where the touch signals are detected or it is detected that the variances of the touch signals or the variation rates of the touch signals are maximum and exceed a preset threshold are determined as the touched positions.

19. The digital capacitive touch screen according to claim 1, wherein

each electrode line connected to the touch system circuit on the touch substrate has an edge in the shape of a fold line, and two adjacent linear segments of the fold line form an angle ranging from 20°

to 160°

.

20. The digital capacitive touch screen according to claim 1, wherein

the electrodes on the touch substrate comprise not only the electrode lines connected to the touch system circuit but also the electrode lines not connected to the touch system circuit.

21. The digital capacitive touch screen according to claim 1, wherein

the at least two staggered electrode groups on the touch substrate are disposed on different substrates, or disposed on different layers isolated by an insulation layer of the same substrate.

22. The digital capacitive touch screen according to claim 1, wherein

the touch substrate is disposed with a shielded electrode insulated from the staggered electrode groups.

23. The digital capacitive touch screen according to claim 1, wherein

the electrode lines connected to the touch system circuit on the touch substrate are disposed on a touch surface or a non-touch surface of the touch substrate.

24. The digital capacitive touch screen according to claim 1, wherein

the touch substrate is a flexible or rigid transparent substrate.