Method and device for position detection

• US 8,536,882 B2
• Filed: 04/16/2010
• Issued: 09/17/2013
• Est. Priority Date: 04/17/2009
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Yeh, Shang-Tai, Ho, Shun-Lung, Chen, Jia-Ming
• Primary Examiner(s): PATEL, PARESH H
• Application Number:
  US12/761,930
• Publication Number:
  US 20100264938A1
• Time in Patent Office: 1,250 Days
• Field of Search: None
• US Class Current: 324/691
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A method and the device for position detection are disclosed. The device comprises a plurality of conductive strips intersecting each other to form a plurality of intersecting regions. A pair of depressed strips intersecting on any intersecting region contact each other to form a depressed intersecting region. When a high voltage and a low voltage are separately provided to the first ends of each pair of overlapping strips, the voltages at the second ends of each pair of overlapping strips are detected so as to determine each depressed intersecting regions.

Claims

1. A device for position detection, comprising:

a sensor including a plurality of conductive stripes constituting a plurality of intersecting regions, wherein a pair of depressed conductive stripes intersected in a intersecting region form a contact point and a depressed intersecting region due to electrical contact;

a driver for providing a high potential and a low potential;

a detector for detecting a signal of at least one conductive stripe;

a selector for operatively coupling the conductive stripes with the driver and the detector; and

a controller for controlling the driver, the detector and the selector to perform at least the following operations;

sequentially selecting one of the conductive stripes as a selected conductive stripe;

providing one of the high potential and the low potential to a first end of the selected conductive stripe, and providing the other one of the high potential and the low potential to a first end of a conductive stripe that intersects with the selected conductive stripe;

detecting the potential at a second end of at least one conductive stripe in the conductive stripes provided with the high and low potentials; and

determining one or both of the depressed conductive stripes and the depressed intersecting region by determining whether one or more conducting paths due to the electrical contact between the pair of depressed conductive stripes are formed based on the potential at the second end of the at least one conductive stripe.

2. The device for position detection of claim 1, wherein when providing the other one of the high potential and the low potential to a plurality of conductive stripes, the depressed conductive stripes are determined.

3. The device for position detection of claim 1, wherein when providing the other one of the high potential and the low potential to a single conductive stripe, the depressed conductive stripes are determined.

4. The device for position detection of claim 1, wherein the determination of depressed conductive stripes is performed before the determination of depressed intersecting region.

5. The device for position detection of claim 4, wherein the depressed conductive stripes indicate a plurality of potentially depressed intersecting regions, and when determining a depressed intersecting region, the selected conductive stripe intersects one of conductive stripes in each potentially depressed intersecting region.

6. The device for position detection of claim 1, wherein when the difference of the potentials at the first and second ends of the same conductive stripe exceeds a predetermined threshold value, this conductive stripe is the depressed conductive stripe or in the depressed intersecting region.

7. The device for position detection of claim 1, wherein the controller further controls the driver, the detector and the selector to perform at least the following operations:

determining contact impedance of each depressed intersecting region, wherein when the high and low potentials are respectively provided to the first ends of one and the other of the pair of depressed conductive stripes, the determination of the contact impedance is based on the potentials at the second ends of one and the other of the pair of depressed conductive stripes and the position of the contact point or the depressed intersecting region.

8. The device for position detection of claim 7, wherein the potentials at the second ends are used to determine the contact impedance and the depressed intersecting region.

9. The device for position detection of claim 7, wherein the controller further controls the driver, the detector and the selector to perform at least the following operations:

sequentially selecting one and the other of each pair of the conductive stripes as a driven conductive stripe and a detected conductive stripe, respectively;

providing the high and low potentials to both ends of the driven conductive stripe;

detecting the potential of the detected conductive stripe as a positional potential when providing the high and low potentials to both ends of the driven conductive stripe; and

determining the position of the contact point based on the positional potentials.

10. The device for position detection of claim 9, wherein the determination of the contact impedance is performed before the determination of the contact point.

11. A method for position detection, comprising:

providing a plurality of intersecting regions constituted by a plurality of intersecting conductive stripes, wherein a pair of depressed conductive stripes intersected in a intersecting region form a contact point and a depressed intersecting region due to electrical contact;

sequentially selecting one of the conductive stripes as a selected conductive stripe;

providing one of a high potential and a low potential to a first end of the selected conductive stripe, and providing the other one of the high potential and the low potential to a first end of a conductive stripe that intersects with the selected conductive stripe;

detecting the potential at a second end of at least one conductive stripe in the conductive stripes provided with the high and low potentials; and

determining one or both of the depressed conductive stripes and the depressed intersecting region by determining whether one or more conducting paths due to the electrical contact between the pair of depressed conductive stripes are formed based on the potential at the second end of the at least one conductive stripe.

12. The method for position detection of claim 11, wherein when providing the other one of the high potential and the low potential to a plurality of conductive stripes, the depressed conductive stripes are determined.

13. The method for position detection of claim 11, wherein when providing the other one of the high potential and the low potential to a single conductive stripe, the depressed conductive stripes are determined.

14. The method for position detection of claim 11, wherein the determination of depressed conductive stripes is performed before the determination of depressed intersecting region.

15. The method for position detection of claim 14, wherein the depressed conductive stripes indicate a plurality of potentially depressed intersecting regions, and when determining a depressed intersecting region, the selected conductive stripe intersects one of conductive stripes in each potentially depressed intersecting region.

16. The method for position detection of claim 11, wherein when the difference of the potentials at the first and second ends of the same conductive stripe exceeds a predetermined threshold value, this conductive stripe is the depressed conductive stripe or in the depressed intersecting region.

17. The method for position detection of claim 11, further comprising:

determining contact impedance of each depressed intersecting region, wherein when the high and low potentials are respectively provided to the first ends of one and the other of the pair of depressed conductive stripes, the determination of the contact impedance is based on the potentials at the second ends of one and the other of the pair of depressed conductive stripes and the position of the contact point or the depressed intersecting region.

18. The method for position detection of claim 17, wherein the potentials at the second ends are used to determine the contact impedance and the depressed intersecting region.

19. The method for position detection of claim 17, further comprising:

sequentially selecting one and the other of each pair of the conductive stripes as a driven conductive stripe and a detected conductive stripe, respectively;

providing the high and low potentials to both ends of the driven conductive stripe;

detecting the potential of the detected conductive stripe as a positional potential when providing the high and low potentials to both ends of the driven conductive stripe; and

determining the position of the contact point based on the positional potentials.

20. The method for position detection of claim 19, wherein the determination of the contact impedance is performed before the determination of the contact point.