Coordinate detecting method and system for touch panel

• US 20050001811A1
• Filed: 03/15/2004
• Published: 01/06/2005
• Est. Priority Date: 03/14/2003
• Status: Active Grant

• Current Assignee: Honour International Co., Ltd.
• Original Assignee: Honour International Co., Ltd.
• Inventors: Lee, Pei Cheng, Kuo, Chen Kun, Chang, Ching-Haur, Chiang, Wu-Chung
• Granted Patent: US 7,170,017 B2
• Time in Patent Office: Days
• US Class Current: 345/107
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/046 by electromagnetic means
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

The invention relates to a coordinate detecting method for a touch panel. Firstly, a plurality of X-axis and Y-axis I/O ports are converted to a plurality of X-axis and Y-axis scanning wires respectively by orthogonal method. Polling signals are transmitted to X-axis I/O ports, and are transmitted to the X-axis scanning wires; According to the polling signals, a plurality of X-axis detection signals are stored. A largest X-axis detection signal and a second largest X-axis detection signal are determined by compared method so as to calculate a X coordinate position of the sensor pen touching the touch panel. The steps are repeated to calculate the Y coordinate position of the sensor pen touching on the touch panel. According to the coordinate detecting method of the invention, the number of the I/O ports can be reduced, and the resolution of the touch panel can be improved. For the calculation method, the invention utilizes simple compared method to obtain the largest detection signal and the second largest detection signal so as to calculate the coordinate position of the sensor pen touching on the touch panel. Therefore, the coordinate detecting method of the invention is very simple and rapid.

Claims

1. A coordinate detecting method for a touch panel, comprising the steps of:

(a) converting a plurality of X-axis I/O ports and a plurality of Y-axis I/O ports respectively to form a plurality of X-axis scanning wires and a plurality of Y axis canning wires of the touch panel by an orthogonal method;

(b) transmitting polling signals to the X-axis I/O ports in sequence, which are then transmitted to the X-axis scanning wires;

(c) storing a plurality of X-axis detection signals from a sensor touching the touch panel according to the polling signals;

(d) determining a largest X-axis detection signal and a second largest X-axis detection signal, then determining an X coordinate position of the sensor on the touch panel;

(e) transmitting polling signals to the Y-axis I/O ports in sequence, which are then transmitted to the Y-axis scanning wires;

(f) storing a plurality of Y-axis detection signals from the sensor touching the touch panel according to the polling signals; and

(g) determining a largest Y-axis detection signal and a second largest Y-axis detection signal, then determining a Y coordinate position of the sensor on the touch panel.

2. The coordinate detecting method according to claim 1, wherein the number of X-axis I/O ports or the number of Y-axis I/O ports is an odd number N, and the maximum number of the X-axis scanning wires or the maximum number of the Y-axis scanning wires is C(N,2)+1.

3. The coordinate detecting method according to claim 1, wherein the number of X-axis I/O ports or the number of Y-axis I/O ports is an even number N, and the maximum number of the X-axis scanning wires or the maximum number of the Y-axis scanning wires is C(N,2)-N/2+2.

4. A coordinate detecting system for a touch panel comprising:

a converting means for converting a plurality of X axis I/O ports and a plurality of Y-axis I/O ports respectively to form a plurality of X-axis scanning wires and a plurality of Y-axis canning wires of the touch panel by orthogonal method;

a control means for transmitting polling signals to the X-axis I/O ports and the +Y-axis I/O ports in order, the X-axis scanning wires and the Y-axis scanning wires having the responding polling signals;

a sensor for detecting a plurality of X-axis detection signals and a plurality of Y-axis detection signals according to, the polling signals;

a database for storing the X-axis detection signals and the Y-axis detection signals from the sensor; and

an arithmetic means for determining a largest X-axis detection signal, a second largest X-axis detection signal, and determining a largest Y-axis detection signal and a second largest value Y-axis detection signal, then determining an X coordinate position and a Y coordinate position of the sensor on the touch panel.

5. The coordinate detecting system according to claim 4, wherein the number of X-axis I/O ports or the number of Y-axis I/O ports is an odd number N, and the maximum number of the X-axis scanning wires or the maximum number of the Y-axis scanning wires is C(N,2)+1.

6. The coordinate detecting system according to claim 4, wherein the number of X-axis I/O ports or the number of Y-axis 10 ports is an even number N, and the maximum number of the X-axis scanning wires or the maximum number of the Y axis scanning wires is C(N,2)-N/2+2.

7. The coordinate detecting system according to Claim 4, wherein the sensor comprises an antenna and a demodulation circuit, the antenna being used to detect the X-axis detection signals and the Y-axis detection signals, and the demodulation circuit being used to demodulate the X-axis detection signals and the Y-axis detection signals, and to transmit the X-axis detection signals and the Y-axis detection signals to the database.

8. The coordinate detecting system according to claim 7, wherein the sensor further comprises a shielding housing for covering the demodulation circuit to isolate the external noise.