TOUCH PANEL DEVICE AND METHOD OF DETECTING CONTACT POSITION THEREOF

• US 20100277433A1
• Filed: 04/30/2008
• Published: 11/04/2010
• Est. Priority Date: 11/07/2007
• Status: Abandoned Application

• Current Assignee: ATLab, Inc.
• Original Assignee: ATLab, Inc.
• Inventors: Joung, Chul-Yong, Lee, Bang-Won, Lee, Sang-Jin
• Application Number:
  US12/740,470
• Publication Number:
  US 20100277433A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

Provided are a touch pad device and a method of detecting a contact position thereof. The touch panel device includes: a touch panel having a surface on which at least one pair of touch patterns formed of a conductive material are formed; and a touch sensor for generating a contact signal corresponding to a contact position of a contact object using impedances of a pair of touch patterns when the pair of touch patterns are contacted by the contact object. The touch panel device includes a plurality of pairs of touch patterns formed of a conductive material. A first axis position of a contact object is determined depending on whether or not the touch patterns are contacted by the contact object, and a second axis position of the contact object is determined by detecting variations in capacitance of the touch patterns or delay times by which a reference signal applied to the touch patterns is delayed. Thus, a contact position of the contact object can be detected using the first and second axis positions. Since the touch panel uses a one-layer ITO film, manufacturing the touch panel device with improved transparency can be easy and economical.

Claims

1. A touch panel device comprising:

a touch panel having a surface on which at least one pair of touch patterns formed of a conductive material are formed; and

a touch sensor for generating a contact signal corresponding to a contact position of a contact object using impedances of a pair of touch patterns when the pair of touch patterns are contacted by the contact object.

2. The device according to claim 1, wherein the pair of touch patterns are patterned such that a region formed of a conductive material is varied according to a coordinate axis position so that when the pair of touch patterns are contacted by the contact object, capacitances of the pair of touch patterns are varied according to the contact position of the contact object.

3. The device according to claim 2, wherein when the pair of touch patterns are contacted by the contact object, the touch sensor determines a first position value corresponding to a first coordinate value using the capacitances of the touch patterns, sets a position of the pair of touch patterns contacted by the contact object among the pairs of touch patterns to a second position value corresponding to a second coordinate value, and generates the contact signal corresponding to the first and second position values.

4. The device according to claim 3, wherein even if a contact area is varied or the first position value is affected by external noise, the touch sensor compensates for a variation in the first position value due to the contact area or the external noise and determines the first position value corresponding to an actual position value of the contact object.

5. The device according to claim 4, wherein the touch sensor compensates for the variation in the first position value using an average of values corresponding to the capacitances of the pair of touch patterns.

6. The device according to claim 3, wherein the touch sensor comprises:

a reference signal generator for generating a clock signal;

a delay signal generator for receiving the clock signal to generate at least two delay signals having delay times corresponding to the capacitances of the pair of touch patterns; and

a contact position signal generator for setting a coordinate value corresponding to a difference and/or a summation of the delay signals to the first position value and setting the position of the pair of touch patterns from which the delay times are detected to the second position value to output the contact signal.

7. The device according to claim 6, wherein the delay signal generator comprises:

a first signal generator connected to a first touch pattern of each of the pairs of touch patterns, the first signal generator for receiving the clock signal to generate a first delay signal delayed according to the capacitance of the first touch pattern; and

a second signal generator connected to a second touch pattern of each of the pairs of touch patterns, the second signal generator for receiving the clock signal to generate a second delay signal delayed according to the capacitance of the second touch pattern.

8. The device according to claim 3, wherein the touch sensor comprises:

a reference signal generator for generating a clock signal;

a delay signal generator for receiving the clock signal to generate at least two delay signals having delay times corresponding to the capacitances of the pair of touch patterns and a comparison signal to be compared with the delay signals; and

a contact position signal generator for comparing each of the two delay signals with the comparison signal, setting the average of contact position values corresponding to the delay times to the first position value, and setting the position of the pair of touch patterns from which the delay times are detected to the second position value to output the contact signal.

9. The device according to claim 8, wherein the delay signal generator comprises:

a first signal generator connected to a first touch pattern of each of the pair of touch patterns, the first signal generator for receiving the clock signal to generate a first delay signal delayed according to the capacitance of the first touch pattern;

a second signal generator connected to a second touch pattern of each of the pairs of touch patterns, the second signal generator for receiving the clock signal to generate a second delay signal delayed according to the capacitance of the second touch pattern; and

a comparison signal generator for receiving the clock signal to generate the comparison signal having a predetermined delay time.

10. The device according to claim 2, wherein each of the pairs of touch patterns is a cross-symmetric touch pattern.

11. The device according to claim 2, wherein each of the pairs of touch patterns is a right-triangular touch pattern.

12. The device according to claim 1, wherein the pair of touch patterns are patterned such that a region formed of the conductive material is constant, irrespective of a coordinate axis position, so that when the pair of touch patterns are contacted by the contact object, resistances of the pair of touch patterns are varied according to the contact position of the contact object.

13. The device according to claim 12, wherein when the pair of touch patterns are contacted by the contact object, the touch sensor determines a first position value corresponding to a first coordinate value using the resistances of the touch patterns, sets a position of the pair of touch patterns contacted by the contact object among the pairs of touch patterns to a second position value corresponding to a second coordinate value, and generates the contact signal corresponding to the first and second position values.

14. The device according to claim 13, wherein even if a contact area is varied or the first position value is affected by external noise, the touch sensor compensates for a variation in the first position value due to the contact area or the external noise and determines the first position value corresponding to an actual position value of the contact object.

15. The device according to claim 14, wherein the touch sensor compensates for the variation in the first position value using an average of values corresponding to the resistances of the pair of touch patterns.

16. The device according to claim 13, wherein the touch sensor comprises:

a reference signal generator for generating a clock signal;

a delay signal generator for receiving the clock signal to generate at least two delay signals having delay times corresponding to the resistances of the pair of touch patterns; and

a contact position signal generator for setting a coordinate value corresponding to a difference and/or a summation of sum of the delay signals to the first position value and setting the position of the pair of touch patterns from which the delay times are detected to the second position value to output the contact signal.

17. The device according to claim 16, wherein the delay signal generator comprises:

a first signal generator connected to a first touch pattern of each of the pairs of touch patterns, the first signal generator for receiving the clock signal to generate a first delay signal delayed according to the resistance of the first touch pattern; and

a second signal generator connected to a second touch pattern of each of the pairs of touch patterns, the second signal generator for receiving the clock signal to generate a second delay signal delayed according to the resistance of the second touch pattern.

18. The device according to claim 13, wherein the touch sensor comprises:

a reference signal generator for generating a clock signal;

a delay signal generator for receiving the clock signal to generate at least two delay signals having delay times corresponding to the resistances of the pair of touch patterns and a comparison signal to be compared with the delay signals; and

a contact position signal generator for comparing each of the two delay signals with the comparison signal, setting the average of contact position values corresponding to the delay times to the first position value, and setting the position of the pair of touch patterns from which the delay times are detected to the second position value to output the contact signal.

19. The device according to claim 18, wherein the delay signal generator comprises:

a first signal generator connected to a first touch pattern of each of the pair of touch patterns, the first signal generator for receiving the clock signal to generate a first delay signal delayed according to the resistance of the first touch pattern;

a second signal generator connected to a second touch pattern of each of the pairs of touch patterns, the second signal generator for receiving the clock signal to generate a second delay signal delayed according to the resistance of the second touch pattern; and

a comparison signal generator for receiving the clock signal to generate the comparison signal having a predetermined delay time.

20. The device according to claim 12, wherein each of the pairs of touch patterns is a symmetric touch pattern.

21. The device according to claim 12, wherein each of the pairs of touch patterns is a rectangular touch pattern.

22. The device according to claim 1, wherein the conductive material comprises substantially indium tin oxide (ITO).

23. A method of detecting a contact position using a touch panel device having a surface on which at least one pair of touch patterns formed of a conductive material are formed, comprising:

detecting varied impedances of a pair of touch patterns contacted by a contact object;

determining a first-axis coordinate value using the impedances of the pair of touch patterns;

setting a position of the pair of touch patterns contacted by the contact object among the pairs of touch patterns to a second-axis coordinate value; and

generating a contact signal corresponding to the first- and second-axis coordinate values.

24. The method according to claim 23, wherein determining the first-axis coordinate value includes:

generating a clock signal;

delaying the clock signal by delay times corresponding to the impedances of the pair of touch patterns to generate a first clock delay signal and a second clock delay signal; and

calculating the first-axis coordinate value corresponding to a difference and/or summation of the first clock delay signal and the second clock delay signal.

25. The method according to claim 23, wherein determining the first-axis coordinate value includes:

generating a clock signal;

generating a comparison signal by delaying the clock signal by a predetermined delay time;

delaying the clock signal by delay times corresponding to the impedances of the pair of touch patterns to generate a first clock delay signal and a second clock delay signal;

determining a first position value corresponding to the delay time by comparing the first clock delay signal with the comparison signal;

determining a second position value corresponding to the delay time by comparing the second clock delay signal with the comparison signal; and

calculating the first-axis coordinate value corresponding to an average value of the first position value and the second position value.

26. The method according to claim 23, wherein the impedance is a capacitance.

27. The method according to claim 23, wherein the impedance is a resistance.