Identification method for touch control device

• US 20060114241A1
• Filed: 06/08/2005
• 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:
  US11/148,577
• Publication Number:
  US 20060114241A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/94031 Calibration involving digital processing
• CPC Class Codes: H03K 2217/960725 Charge-transfer

Abstract

An identification method for a touch control device having a memory and a pad electrically connected to an equivalent capacitance is provided. The provided identification method for a touch control device includes steps of: (a) charging the equivalent capacitance for obtaining a first voltage value; (b) storing the first voltage value in the memory; (c) touching the pad; (d) scanning the pad for obtaining a second voltage value of the equivalent capacitance; and (e) comparing the first voltage value with the second voltage of the equivalent capacitance for identifying a touched position on the pad.

Claims

1. An identification method for a touch control device having a memory and a pad electrically connected to an equivalent capacitance, comprising:

(a) charging said equivalent capacitance for obtaining a first voltage value;

(b) storing said first voltage value in said memory;

(c) touching said pad;

(d) scanning said pad for obtaining a second voltage value of said equivalent capacitance; and

(e) comparing said first voltage value with said second voltage value of said equivalent capacitance for identifying a touched position on said pad.

2. The identification method as claimed in claim 1;

wherein said touch control device further comprises an integrator and said step (a) further comprises;

(a1) providing a first pulse as a first energy to said equivalent capacitance;

(a2) storing said first energy in said integrator;

(a3) amplifying and converting a first output of said integrator to a first digital signal; and

(a4) multiplying said first digital signal by a numeral for obtaining said first voltage value.

3. The identification method as claimed in claim 2, wherein said step (b) further comprises:

(b1) eliminating said first energy stored in said integrator.

4. The identification method as claimed in claim 2, wherein said number is set by a user for flexibly changing an identification sensitivity of said touch control device.

5. The identification method as claimed in claim 2, wherein said memory and said integrator are incorporated in a micro controlled unit (MCU).

6. The identification method as claimed in claim 1, wherein said step (c) further comprises steps of:

(c1) providing a second pulse as a second energy to said equivalent capacitance;

(c2) storing said second energy in said integrator; and

(c3) amplifying and converting a second output of said integrator to a second digital signal for obtaining said second voltage value.

7. The identification method as claimed in claim 1, wherein said touch control device further comprises a micro controlled unit (MCU) for controlling each of said steps.

8. The identification method as claimed in claim 1, wherein said memory is a random access memory (RAM).

9. An identification method for a touch control device having a memory and plural keys and each said key is electrically connected to a capacitor, comprising:

(a) charging each said capacitor for obtaining a respective first voltage value;

(b) storing said respective first voltage value in said memory;

(c) touching at least one of said keys;

(d) scanning each said key for obtaining a respective second voltage value of said capacitor; and

(e) comparing said first voltage value with said second voltage valve of each said capacitor for identifying whether each said key is touched.

10. The identification method as claimed in claim 9, wherein said touch control device further comprises an integrator and said step (a) further comprises:

(a1) providing a first pulse as a first energy to each said capacitor;

(a2) storing each said first energy in said integrator;

(a3) amplifying and converting a first output of said integrator to a first digital signal; and

(a4) multiplying said first digital signal by a numeral for obtaining said respective first voltage level.

11. The identification method as claimed in claim 10, wherein said step (b) further comprises:

(b1) eliminating said first energy stored in said integrator.

12. The identification method as claimed in claim 10, wherein said numeral is set by a user for flexibly changing an identification sensitivity of said touch control device.

13. The identification method as claimed in claim 10, wherein said memory and said integrator are incorporated in a micro controlled unit (MCU).

14. The identification method as claimed in claim 9, wherein said step (c) further comprises steps of:

(c1) providing a second pulse as a second energy to each said capacitor;

(c2) storing said second energy in said integrator; and

(c3) amplifying and converting a second output of said integrator to a second digital signal for gaining said second voltage value.

15. The identification method as claimed in claim 9, wherein said touch control device further comprises a micro controlled unit (MCU) for controlling each of said steps.

16. The identification method as claimed in claim 9, wherein said memory is a random access memory (RAM).