Method and Device for Position Detection

• US 20120007612A1
• Filed: 09/21/2011
• Published: 01/12/2012
• 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, Chen, Jia-Ming, Ho, Shun-Lung
• Granted Patent: US 8,633,719 B2
• Time in Patent Office: Days
• US Class Current: 324/649
• 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 device comprises a plurality of strips intersecting each other to form a plurality of intersecting regions. A pair of strips intersecting on an intersecting region contact to each other on a contact point to form a depressed intersecting region. The erroneously determined intersecting regions can be detected by comparing the contact points with the corresponding intersecting regions so as to provide the only correct contact points.

Claims

1. A method for position detection, comprising:

providing a plurality of intersecting regions constituted by a plurality of intersecting conductive stripes;

determining whether each intersecting region is a depressed intersecting region by determining whether there is a conduction path between a pair of conductive stripes intersected in the intersecting region;

determining the position of a contact point corresponding to each depressed intersecting region;

performing a filter procedure to provide a position of the contact point falling within a predetermine range corresponding to the intersecting region; and

determining the position of at least one depression based on the provided position of the contact point.

2. The method for position detection of claim 1, further comprising the step of determining a depression corresponding to each depressed intersecting region, wherein the depressed intersecting regions corresponding to the same depression are neighboring intersecting regions.

3. The method for position detection of claim 2, wherein only a position of the depression that all contact points fall within corresponding intersecting region is provided when the position of at least one contact of at least one depression falls outside the corresponding intersecting region.

4. The method for position detection of claim 3, wherein the position of the depression is determined based on the positions of all contact points corresponding to the same depression.

5. The method for position detection of claim 3, further comprising:

determining a contact impedance of each depressed intersecting region; and

determining a total contact impedance for each depression, wherein the total contact impedance is the parallel impedance of contact impedances of all intersecting regions corresponding to the same depression.

6. The method for position detection of claim 5, wherein the position of the depression is not determined when the total contact impedance of the depression is smaller than a threshold value.

7. The method for position detection of claim 5, wherein the contact impedance is determined by the potentials of one and the other of the pair of conductive stripes at the contact point and the position of the contact point, and the determination of the contact impedance comprises:

determining a first dimensional location and a second dimensional location of the contact point, and determining a first dimensional impedance and a second dimensional impedance based on the first dimensional location and the second dimensional location;

detecting a first contact potential and a second contact potential of one and the other of a pair of conductive stripes when a high potential and a low potential are provided to one and the other of a pair of conductive stripes, respectively; and

determining the contact impedance, wherein the contact impedance is (R1+R2)/(((VH−

VL)/(P1−

P2))−

1), wherein R1, R2, VH, VL, P1, and P2 are the first dimensional impedance, the second dimensional impedance, the high potential, the low potential, the first contact potential, and the second contact potential, respectively.

8. The method for position detection of claim 5, wherein the contact impedance is determined by the potentials of one and the other of the pair of conductive stripes at the contact point and the position of the depressed intersecting region, and the determination of the contact impedance comprises:

determining a first dimensional impedance and a second dimensional impedance based on the position of the depressed intersecting region;

detecting a first contact potential and a second contact potential of one and the other of a pair of conductive stripes when a high potential and a low potential are provided to one and the other of a pair of conductive stripes, respectively; and

determining the contact impedance, wherein the contact impedance is (R1+R2)/(((VH−

VL)/(P1−

P2))−

1), wherein R1, R2, VH, VL, P1, and P2 are the first dimensional impedance, the second dimensional impedance, the high potential, the low potential, the first contact potential, and the second contact potential, respectively.

9. The method for position detection of claim 1, wherein the determination of the contact point of the intersecting region comprises:

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

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

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

10. The method for position detection of claim 1, wherein the determination of the contact point of the intersecting region comprises:

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

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

electrically coupling an extension resistor and the driven conductive stripe to form an extension conductive stripe;

providing high and low potentials to the extension conductive stripe to detect the potential between the extension resistor and the driven conductive stripe as a non-depressed potential when the extension conductive stripe is not depressed;

providing high and low potentials to the extension conductive stripe to detect the potential between the extension resistor and the driven conductive stripe as a depressed potential when the extension conductive stripe is depressed; and

determining the position of a contact point on the driven conductive stripe based on the positional potential, the non-depressed and depressed potentials of the driven conductive stripe.

20. The device for position detection of claim 1, wherein the determination of the contact point of the intersecting region comprises:

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

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

electrically coupling an extension resistor and the driven conductive stripe to form an extension conductive stripe;

providing high and low potentials to the extension conductive stripe to detect the potential between the extension resistor and the driven conductive stripe as a non-depressed potential when the extension conductive stripe is not depressed;

providing high and low potentials to the extension conductive stripe to detect the potential between the extension resistor and the driven conductive stripe as a depressed potential when the extension conductive stripe is depressed; and

determining the position of a contact point on the driven conductive stripe based on the positional potential, the non-depressed and depressed potentials of the driven conductive stripe.

11. A device for position detection, comprising:

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

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;

determining the position of a contact point corresponding to each depressed intersecting region;

performing a filter procedure to provide a position of the contact point falling within a predetermine range corresponding to the intersecting region; and

determining the position of at least one depression based on the provided position of the contact point.

12. The device for position detection of claim 11, wherein the controller further controls the driver, the detector and the selector to perform the following operation of determining a depression corresponding to each depressed intersecting region, wherein the depressed intersecting regions corresponding to the same depression are neighboring intersecting regions.

13. The device for position detection of claim 12, wherein only a position of the depression that all contact points fall within corresponding intersecting region is provided when the position of at least one contact of at least one depression falls outside the corresponding intersecting region.

14. The device for position detection of claim 13, wherein the position of the depression is determined based on the positions of all contact points corresponding to the same depression.

15. The device for position detection of claim 13, wherein the controller further controls the driver, the detector and the selector to perform the following operations:

determining a contact impedance of each depressed intersecting region; and

determining a total contact impedance for each depression, wherein the total contact impedance is the parallel impedance of contact impedances of all intersecting regions corresponding to the same depression.

16. The device for position detection of claim 15, wherein the position of the depression is not determined when the total contact impedance of the depression is smaller than a threshold value.

17. The device for position detection of claim 15, wherein the contact impedance is determined by the potentials of one and the other of the pair of conductive stripes at the contact point and the position of the contact point, and the determination of the contact impedance comprises:

determining a first dimensional location and a second dimensional location of the contact point, and determining a first dimensional impedance and a second dimensional impedance based on the first dimensional location and the second dimensional location;

detecting a first contact potential and a second contact potential of one and the other of a pair of conductive stripes when high and low potentials are provided to one and the other of a pair of conductive stripes, respectively; and

determining the contact impedance, wherein the contact impedance is (R1+R2)/(((VH−

VL)/(P1−

P2))−

1), wherein R1, R2, VH, VL, P1, and P2 are the first dimensional impedance, the second dimensional impedance, the high potential, the low potential, the first contact potential, and the second contact potential, respectively.

18. The device for position detection of claim 15, wherein the contact impedance is determined by the potentials of one and the other of the pair of conductive stripes at the contact point and the position of the depressed intersecting region, and the determination of the contact impedance comprises:

determining a first dimensional impedance and a second dimensional impedance based on the position of the depressed intersecting region;

detecting a first contact potential and a second contact potential of one and the other of a pair of conductive stripes when high and low potentials are provided to one and the other of a pair of conductive stripes, respectively; and

determining the contact impedance, wherein the contact impedance is (R1+R2)/(((VH−

VL)/(P1−

P2))−

1), wherein R1, R2, VH, VL, P1, and P2 are the first dimensional impedance, the second dimensional impedance, the high potential, the low potential, the first contact potential, and the second contact potential, respectively.

19. The device for position detection of claim 17, wherein the determination of the contact point of the intersecting region comprises:

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

detecting the potential of the detected conductive stripe as a positional potential when providing 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.