Device and method for preventing the influence of conducting material from point detection of projected capacitive touch panel

• US 8,546,705 B2
• Filed: 03/19/2009
• Issued: 10/01/2013
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu, Lee, Cheng-Han, Lin, Yu-Han
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): Li, Lin
• Application Number:
  US12/407,100
• Publication Number:
  US 20090255737A1
• Time in Patent Office: 1,657 Days
• Field of Search: 345173-174, 178/18.06, 204/416, 250/208.2, 348/308, 341/26
• US Class Current: 178/18.06
• 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

This invention provides a device for preventing the influence of conducting material from point detection of projected capacitive touch panel. The device includes a first sensing layer having a plurality of first axial conductive lines isolated from each other and electrically connected to a plurality of first outside-connection conducting wires correspondingly, a second sensing layer having a plurality of second axial conductive lines isolated from each other and electrically connected to a plurality of second outside-connection conducting wires correspondingly, a signal driving line electrically connecting to the first and the second outside-connection conducting wires to provide a first sensing signal, and a sensing unit electrically connecting the first and the second outside-connection conducting wires to sense the sensing signal on the first and the second axial conductive lines. Wherein, the second sensing layer is on a dielectric layer, the first sensing layer, and a substrate in sequence.

Claims

1. A device for preventing the influence of conducting material from point detection of projected capacitive touch panel, said device comprises:

a first sensing layer, having a plurality of first axial conductive lines isolated from each other and correspondingly electrically connected to a plurality of first outside-connection conducting wires, wherein the plurality of the first axial conductive lines comprise all the conductive lines on the first sensing layer;

a second sensing layer, having a plurality of second axial conductive lines isolated from each other and correspondingly electrically connected to a plurality of second outside-connection conducting wires, wherein said second sensing layer is on a dielectric layer, said first sensing layer, and a substrate in sequence, wherein the plurality of the second axial conductive lines comprise all the conductive lines on the second sensing layer;

a signal driving line, electrically connecting to said plurality of second outside-connection conducting wires to provide a first sensing signal concurrently; and

a sensing unit, electrically connecting said plurality of first and second outside-connection conducting wires to sense the sensing signals on said plurality of first axial conductive lines and second axial conductive lines;

wherein said sensing signals of said plurality of first axial conductive lines on said first sensing layer, and said sensing signals of said plurality of second axial conductive lines on said second sensing layer, are provided concurrently;

wherein said signal driving line further electrically connects to said plurality of first outside-connection conducting wires.

2. The device according to claim 1, wherein said first sensing layer, said plurality of first axial conductive lines, said second sensing layer, said plurality of second axial conductive lines, said dielectric layer and said substrate are transparent material.

3. The device according to claim 1, wherein said first sensing layer further comprises a plurality of first patterned transparent electrodes serially connected to said plurality of first axial conductive lines in cycle, said second sensing layer further comprises a plurality of second patterned transparent electrodes serially connected to said plurality of second axial conductive lines in cycle.

4. The device according to claim 1, wherein said signal driving line electrically connects to a control switch to receive and transmit said first sensing signal.

5. The device according to claim 4, wherein said control switch comprises one of follows:

an electronic switch and electromechanical switch.

6. The device according to claim 1, wherein said sensing unit electrically connects to said plurality of first and second outside-connection conducting wires by at least one multiplexer.

7. The device according to claim 1, wherein said sensing unit comprises at least one of follows:

a current detector and a charge detector.

8. The device according to claim 1, wherein each of said second axial conductive lines electrically connects to said signal driving line.

9. A method for preventing the influence of conducting material from point detection of projected capacitive touch panel, said method comprising:

(a) providing a first sensing signal to a plurality of first axial conductive lines on a first sensing layer and a plurality of second axial conductive lines on a second sensing layer, concurrently, wherein the plurality of the first axial conductive lines comprise all the conductive lines on the first sensing layer, the plurality of the second axial conductive lines comprise all the conductive lines on the second sensing layer, and said plurality of first and second axial conductive lines are electrically isolated from, and perpendicular to, each other;

(b) sensing a plurality of second sensing signals and third sensing signals, wherein said plurality of second sensing signals are correspondingly generated by said plurality of first axial conductive lines receiving said first sensing signal, said plurality of third sensing signals are correspondingly generated by said plurality of second axial conductive lines receiving said first sensing signal, wherein the plurality of third sensing signals includes the stray capacitance between the first axial conductive lines and the second axial conductive lines; and

(c) utilizing at least one bigger change of said plurality of second and third sensing signals respectively to match a corresponding coordinate to get the position of at least one touch point on said corresponding coordinate.

10. The method according to claim 9, wherein a transparent dielectric layer is inserted between and used to isolate said plurality of first and second axial conductive lines.

11. The method according to claim 9, wherein step (b) comprises:

sensing said plurality of second and third sensing signals simultaneously.

12. The method according to claim 9, wherein step (b) comprises:

sensing said plurality of second and third sensing signals in sequence respectively.

13. The method according to claim 9, wherein step (b) comprises:

sensing said plurality of second and third sensing signals by selected respectively.

14. The method according to claim 9, wherein said first sensing signal is provided by at least one of follows:

a voltage-sensing source and a current-sensing source.

15. The method according to claim 9, wherein said plurality of second and third sensing signals are sensed by at least one of follows:

a current detector and a charge detector.

16. The method according to claim 9, wherein entire said first and entire said second axial conductive lines have the same voltage level when entire said first and entire said second axial conductive lines are provided said first sensing signal concurrently.

17. A method for preventing the influence of conducting material from point detection of projected capacitive touch panel, said method comprising:

(a) providing a first sensing signal to a plurality of first axial conductive lines concurrently, wherein said plurality of first axial conductive lines comprise all the conductive lines on a first sensing layer and are electrically isolated from each other;

(b) sensing a plurality of sensing signals of said plurality of first axial conductive lines and a plurality of sensing signals of a plurality of second axial conductive lines, wherein said plurality of second axial conductive lines comprise all the conductive lines on a second sensing layer and are electrically isolated from each other and are isolated from, and perpendicular to, said plurality of first axial conductive lines, said plurality of sensing signals of said plurality of first axial conductive lines are correspondingly generated by said plurality of first axial conductive lines receiving said first sensing signal, said plurality of sensing signals of said plurality of second axial conductive lines are correspondingly generated by said plurality of second axial conductive lines capacitively coupling said plurality of sensing signals of said plurality of first axial conductive lines; and

(c) utilizing at least one bigger change of said plurality of sensing signals of said plurality of first and second axial conductive lines respectively to match a corresponding coordinate to get the position of at least one touch point on said corresponding coordinate;

wherein said plurality of sensing signals of said plurality of first axial conductive lines on said first sensing layer, and said plurality of sensing signals of said plurality of second axial conductive lines on said second sensing layer, are provided concurrently;

wherein said plurality of sensing signals of said plurality of second axial conductive lines comprise the stray capacitance between said plurality of first axial conductive lines and second axial conductive lines.

18. The method according to claim 17, wherein a transparent dielectric layer is inserted between and used to isolate said plurality of first and second axial conductive lines.

19. The method according to claim 17, wherein step (b) comprises:

sensing said plurality of sensing signals of said plurality of first and second conductive lines simultaneously.

20. The method according to claim 17, wherein step (b) comprises:

sensing said plurality of sensing signals of said plurality of first and second axial conductive lines in sequence respectively.

21. The method according to claim 17, wherein step (b) comprises:

sensing said plurality of sensing signals of said plurality of first and second axial conductive lines by selected respectively.

22. The method according to claim 17, wherein said first sensing signal is provided by at least one of follows:

a voltage-sensing source and a current-sensing source.

23. The method according to claim 17, wherein said plurality of sensing signals of said plurality of first and second axial conductive lines are sensed by at least one of follows:

a current detector and a charge detector.

24. The method according to claim 17, wherein entire said first axial conductive lines have the same voltage level when entire said first axial conductive lines are provided said first sensing signal concurrently.