Method and Device for Correcting Position Error

• US 20120007611A1
• Filed: 09/20/2011
• 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: Chen, Jia-Ming, Ho, Shun-Lung, Yeh, Shang-Tai
• Granted Patent: US 8,536,884 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 method and the device for position detection are disclosed. The device comprises a plurality of strips intersecting each other to form a plurality of intersecting regions. A pair of depressed strips intersecting on an intersecting region contact to each other on a contact point to form a depressed intersecting region. According to the voltages of each strip before and after the strip is depressed, an error ratio can be determined. Based on the error ration, the position error caused by the contact impedance crossover strips can be corrected.

Claims

1. A device for correcting position error, comprising:

a sensor including a plurality of conductive stripes constituting a plurality of intersecting regions, wherein a pair of depressed 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;

detectring a non-depressed potential at one end of each conductive stripe;

detectring a depressed potential at the end of each conductive stripe; and

determining a proportion of error at the contact point on each depressed conductive stripe based on the non-depressed potential and the depressed potential.

2. The device for correcting position error of claim 1, wherein the detection of the non-depressed potential and the depressed potential comprises:

sequentially selecting one of the conductive stripes as a 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 the non-depressed potential when the extension conductive stripe is not depressed; and

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

3. The device for correcting position error of claim 2, wherein the proportion of error is

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

detecting the position of each contact point, wherein when a contact impedance across conductive stripes on the same layer is detected at the depressed conductive stripes, the position is the non-corrected position including an error due to the contact impedance across conductive stripes on the same layer; and

correcting the error according to the non-corrected position and the proportion of error.

5. The device for correcting position error of claim 4, wherein the detection of position of the contact point 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 detected potential when providing high and low potentials to both ends of the driven conductive stripe; and

determining the position based on the detected potentials of the pair of depressed conductive stripes.

6. The device for correcting position error of claim 5, wherein the detection of position of the contact point comprises:

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

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

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

7. The device for correcting position error of claim 6, wherein when the contact point on one of the pair of conductive stripes is located between the contact impedance across conductive stripes on the same layer and the end being provided the high potential, the detected potential at the position on one of the pair of conductive stripes is

8. The device for correcting position error of claim 6, wherein when the contact point on one of the pair of conductive stripes is located between the contact impedance across conductive stripe on the same layer and the end being provided the low potential, the detected potential at the position on one of the pair of conductive stripes is

9. The device for correcting position error of claim 1, wherein the controller further controls the driver, the detector and the selector to perform the following operation of determining the pair of the depressed conductive stripes by determining whether there is a conducting path between the conductive stripes in each intersecting region, wherein the detection of the non-depressed potential is performed before the determination of the depressed conductive stripe.

10. The device for correcting position error of claim 1, wherein the controller further controls the driver, the detector and the selector to perform the following operation of determining the depressed conductive stripes by determining whether there is a conducting path between each conductive stripe and any intersecting conductive stripe, wherein the conductive stripes are respectively located at a first and a second conductive stripe layers being intersected, and a plurality of insulating spacers are dispersed between the first and the second conductive stripe layers.

11. A method for correcting position error, comprising:

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

detectring a non-depressed potential at one end of each conductive stripe when the conductive stripe is not depressed;

detectring a depressed potential at the end of each depressed conductive stripe; and

determining a proportion of error at the contact point on each depressed conductive stripe based on the non-depressed potential and the depressed potential.

12. The method for correcting position error of claim 11, wherein the detection of the non-depressed potential and the depressed potential comprises:

sequentially selecting one of the conductive stripes as a 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 the non-depressed potential when the extension conductive stripe is not depressed; and

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

13. The method for correcting position error of claim 12, wherein the proportion of error is

14. The method for correcting position error of claim 12, further comprising:

detecting the position of each contact point, wherein when a contact impedance across conductive stripes on the same layer is detected at the depressed conductive stripes, the position is the non-corrected position including an error due to the contact impedance across conductive stripes on the same layer; and

correcting the error according to the non-corrected position and the proportion of error.

15. The method for correcting position error of claim 14, wherein the detection of position of the contact point 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 detected potential when providing high and low potentials to both ends of the driven conductive stripe; and

determining the position based on the detected potentials of the pair of depressed conductive stripes.

16. The method for correcting position error of claim 15, wherein the detection of position of the contact point comprises:

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

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

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

17. The method for correcting position error of claim 16, further comprising:

when the contact point on one of the pair of conductive stripes is located between the contact impedance across conductive stripes on the same layer and the end being provided the high potential, the detected potential at the position on one of the pair of conductive stripes is

18. The method for correcting position error of claim 16, wherein when the contact point on one of the pair of conductive stripes is located between the contact impedance across conductive stripe on the same layer and the end being provided the low potential, the detected potential at the position on one of the pair of conductive stripes is

19. The method for correcting position error of claim 11, further comprising the following operation of determining the pair of the depressed conductive stripes by determining whether there is a conducting path between the conductive stripes in each intersecting region, wherein the detection of the non-depressed potential is performed before the determination of the depressed conductive stripe.

20. The method for correcting position error of claim 11, further comprising the following operation of determining the pair of the depressed conductive stripes by determining whether there is a conducting path between the conductive stripes in each intersecting region, wherein the detection of the non-depressed potential is performed before the determination of the depressed conductive stripe.

21. A method for correcting position error during handwriting, comprising:

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

determining a depression of a pen and a depression of a palm across conductive stripes on the intersecting regions;

determining the position of the depression of the pen, wherein on the conductive stripe which is depressed simultaneously by the pen and the palm, an error in the position of the depression of the pen is caused by the depression of the palm across conductive stripes; and

correcting the error when the pen depresses the conductive stripe depressed by the palm.

22. The method for correcting position error during handwriting of claim 21, wherein a pair of depressed conductive stripes intersected in an intersecting region form a contact point due to electrical contact so as to define a depressed intersecting region, and the position of the depression of the pen is determined based on the position of at least one contact point, wherein the determination of the position of the contact point comprises:

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

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

determining the position of the contact point based on the detected potentials of the pair of depressed conductive stripes.

23. The method for correcting position error during handwriting of claim 22, wherein the correction of the error comprises:

detecting a non-depressed potential at one end of the conductive stripe before the palm depresses the conductive stripe;

detecting a depressed potential at the end of the conductive stripe after the palm depresses the conductive stripe; and

correcting the error based on the non-depressed potential, depressed potential and the position of the contact point detected on the conductive stripe depressed by the palm.

24. The method for correcting position error during handwriting of claim 21, wherein the error is corrected based on a proportion of error, and the determination of the proportion of error comprises:

detecting a non-depressed potential at one end of each conductive stripe;

detecting a depressed potential at the end of each depressed conductive stripe; and

determining the proportion of error on each depressed conductive stripe based on the non-depressed potential and depressed potential.