Detection method of touch-panel device

• US 20060114242A1
• Filed: 11/17/2005
• Published: 06/01/2006
• Est. Priority Date: 11/29/2004
• Status: Abandoned Application

• Current Assignee: Holtek Semiconductor Incorporated
• Original Assignee: Holtek Semiconductor Incorporated
• Inventors: Lin, Yi-Chan
• Application Number:
  US11/281,850
• Publication Number:
  US 20060114242A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A detection method for a touch-panel device having a touch pad electrically connected to at least m×n equivalent capacitors is provided, wherein m is a number of the equivalent capacitors on a specific one of rows and n is a number of the equivalent capacitors on a specific one of columns. The method includes steps of: (a) charging the m equivalent capacitors on the specific row to obtain m digital signals; (b) comparing potentials of the m digital signals and obtaining a relatively smallest potential as a standard value; (c) repeating the steps (a)˜(b) to obtain n the standard values for the m×n equivalent capacitors; (d) touching the touch pad; (e) scanning the touch pad to obtain at least a potential variation value relative to the standard value for the m equivalent capacitors on the specific row; and (f) comparing the standard value with the variation value to identify a touched point on the touch pad.

Claims

1. A detection method for a touch-panel device having a touch pad electrically connected to at least m×

n equivalent capacitors, wherein m is a number of said equivalent capacitors on a specific one of rows and n is a number of said equivalent capacitors on a specific one of columns, comprising steps of;

(a) charging said m equivalent capacitors on said specific row to obtain m digital signals;

(b) comparing potentials of said m digital signals and obtaining a relatively smallest potential as a standard value;

(c) repeating said steps (a)˜

(b) to obtain n said standard values for said m ×

n equivalent capacitors;

(d) touching said touch pad;

(e) scanning said touch pad to obtain at least a potential variation value relative to said standard value for said m equivalent capacitors on said specific row; and

(f) comparing said standard value with said variation value to identify a touched point on said touch pad.

2. The detection method according to claim 1, wherein said touch-panel device further comprises an integrator and a memory, and said step (a) further comprises steps of:

providing said m equivalent capacitors with a first pulse as a first energy;

saving said first energy in said integrator;

amplifying and converting a first output waveform of said integrator to a first digital signal; and

storing said first digital signal in said memory.

3. The detection method according to claim 2, wherein said step (b) further comprises a step of:

removing said first energy from said integrator.

4. The detection method according to claim 2, between said step (d) and said step (e) further comprising steps of:

Providing m said equivalent capacitors with a second pulse as a second energy;

saving said second energy in said integrator; and

amplifying and converting a second output waveform from said integrator to a second digital signal as said variation value.

5. The detection method according to claim 2, wherein said memory and said integrator are integrated in a micro controller unit (MCU).

6. The detection method according to claim 2, wherein said memory is a random access memory (RAM).

7. The detection method according to claim 2, wherein said step (b) further comprises steps of:

multiplying said relatively smallest first digital signal by a factor to obtain said standard value; and

storing said standard value in said memory.

8. The detection method according to claim 7, wherein said factor is determined by a user for adjusting a sensitivity of said touch pad.

9. The detection method according to claim 1, wherein said touch-panel device further comprises a micro controller unit (MCU) for controlling said steps.

10. A detection method for a touch-panel device having a touch pad electrically connected to a plurality of equivalent capacitors, comprising steps of:

(a) charging said equivalent capacitors to obtain digital signals;

(b) comparing potentials of said digital signals and obtaining a relatively smallest potential as a standard value;

(c) touching said touch pad;

(d) scanning said touch pad to obtain at least a variation value relative to said standard value for each of said equivalent capacitors; and

(e) comparing said standard value with said variation value to identify a touched point on said touch pad.

11. The detection method according to claim 10, wherein said touch-panel device further comprises an integrator and a memory, and said step (a) further comprises steps of:

providing a first pulse to each of said equivalent capacitors as a first energy;

saving said first energy in said integrator;

amplifying and converting a first output waveform from said integrator to a first digital signal; and

storing said first digital signal in said memory.

12. The detection method according to claim 11, wherein said step (b) further comprises steps of:

multiplying said relatively smallest first digital signal by a factor to obtain said standard value; and

storing said standard value in said memory.

13. The detection method according to claim 11, wherein said step (b) further comprises a step of:

removing said first energy from said integrator.

14. The detection method according to claim 11, between said step (c) and said step (d) further comprising steps of:

providing a second pulse to each of said equivalent capacitors as a second energy;

saving said second energy in said integrator; and

amplifying and converting a second output waveform from said integrator to a second digital signal as said variation value.

15. The detection method according to claim 11, wherein said memory and said integrator are integrated in a micro controller unit (MCU).

16. The detection method according to claim 11, wherein said memory is a random access memory (RAM).

17. The detection method according to claim 12, wherein said factor is determined by a user for adjusting a sensitivity of said touch pad.

18. The detection method according to claim 10, wherein said touch-panel device further comprises a micro controller unit (MCU) for controlling said steps.

19. A detection method for a touch-panel device having m×

pads respectively electrically connected to capacitors, wherein m is a number of said pads on a specific one of rows and n is a number of said pads on a specific one of columns, comprising steps of;

(a) charging said m capacitors on said specific row to obtain m digital signals;

(b) comparing potentials of said m digital signals and obtaining a relatively smallest potential as a standard value;

(c) repeating said steps (a)˜

(b) to obtain n said standard values for said m×

n said capacitors;

(d) touching said touch-panel device;

(e) scanning said touch-panel device to obtain at least a variation value relative to said standard value for said m capacitors on said specific row; and

(f) comparing said standard value with said variation value to identify a touched pad on said touch-panel device.

20. A detection method for a touch-panel device having at least one pad electrically connected to a capacitor, comprising steps of:

charging said capacitor to obtain a digital signal;

detecting a potential of said digital signal and obtaining a potential as a standard value;

touching said touch-panel device;

scanning said touch-panel device to obtain at least a variation value relative to said standard value for said capacitor; and

comparing said standard value with said variation value to identify a touched pad on said touch-panel device.