Touch sensor with non-uniform resistive band

• US 7,265,686 B2
• Filed: 07/15/2003
• Issued: 09/04/2007
• Est. Priority Date: 07/15/2003
• Status: Expired due to Fees

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Kent, Joel C., Warmack, Robert J., Hurst, G. Samuel, Bouldin, Donald W., Ritchie, R. H.
• Primary Examiner(s): Zimmerman; Brian
• Assistant Examiner(s): Dang; Hung Q
• Application Number:
  US10/619,915
• Publication Number:
  US 20050012644A1
• Time in Patent Office: 1,512 Days
• Field of Search: 341/33, 341/34, 345/177, 345/173, 345/179, 178/18.04, 178/18.05, 178/19.04, 178/18.01
• US Class Current: 341/33
• CPC Class Codes: G06F 2203/04113 Peripheral electrode pattern in resistive digitisers, i.e. electrodes at the periphery of the resistive sheet are shaped in patterns enhancing linearity of induced field
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A touch sensors with improved topological equivalence between an equipotential space and a Cartesian space to which the equipotential space will be mapped. The touch sensor comprises a substrate with a touch region, and a set of electrodes that are electrically coupled to the touch region. The touch sensor further comprises a plurality of resistive band segments that frames the touch region. The electrodes are located between the resistive band segments. Each resistive band segment has a resistivity that is intermediate between the resistivity of the electrodes and the resistivity of the touch region, thereby providing a transition between the low resistivity electrodes and the high resistivity touch region, and improving the topological equivalence within the corners of the touch region. At least one of the band segments has a non-uniform linear resistance to provide further improvement to the topological equivalence.

Claims

1. A touch sensor, comprising:

a substrate having a resistive touch region;

a set of electrodes electrically coupled to the touch region; and

a plurality of band segments framing the touch region and having an intermediate resistivity between the resistivity of the electrodes and the resistivity of the touch region, wherein the electrodes are disposed between the band segments, and at least one of the band segments has a linear resistance that varies along its length and has a width that varies along its length, each band segment being continuous or quasi-continuous along at least a portion of its length.

2. A touch sensor, comprising:

a substrate having a resistive touch region;

a set of electrodes electrically coupled to the touch region; and

a plurality of band segments framing the touch region and having an intermediate resistivity between the resistivity of the electrodes and the resistivity of the touch region, wherein the electrodes are disposed between the band segments, and at least one of the band segments has a linear resistance that varies along its length and has a thickness that varies along its length, each band segment being continuous or quasi-continuous along at least a portion of its length.

3. The touch sensor, comprising:

a substrate having a resistive touch region;

a set of electrodes electrically coupled to the touch region; and

a plurality of band segments framing the touch region and having an intermediate resistivity between the resistivity of the electrodes and the resistivity of the touch region, wherein the electrodes are disposed between the band segments, and at least one of the band segments has a linear resistance that varies along its length and comprises an array of electrically conductive elements, the conductive elements having a spacing or size that varies along the length of the at least one band segment, each band segment being continuous or quasi-continuous along at least a portion of its length.

4. A dynamic touch sensor system, comprising:

a touch sensor that generates touch information in response to a touch and generates measurable information indicative of a given electrical characteristic in the touch sensor, the touch sensor comprising a substrate having a resistive touch region, a set of electrodes electrically coupled to the touch region, and a band framing the touch region and having a resistivity intermediate the resistivity of the electrodes and the resistivity of the touch region, wherein the band has a substantially non-uniform linear resistance, the band being continuous or quasi-continuous along at least a portion of its length, and having a width that varies along its length; and

control electronics coupled to the electrodes for receiving the touch information and measurable information from the touch sensor, wherein the control electronics uses an algorithm to determine the coordinates of the location of the touch in the touch region based on the touch information, and modifies the algorithm based on the measurable information.

5. A dynamic touch sensor system, comprising:

a touch sensor that generates touch information in response to a touch and generates measurable information indicative of a given electrical characteristic in the touch sensor, the touch sensor comprising a substrate having a resistive touch region, a set of electrodes electrically coupled to the touch region, and a band framing the touch region, and a band framing the touch region and having a resistivity intermediate and the resistivity of the electrodes and the resistivity of the touch region, wherein the band has a substantially non-uniform linear resistance, the band being continuous or quasi-continuous along at least a portion of its length and having a thickness that varies along its length; and

control electronics coupled to the electrodes for receiving the touch information and measurable information from the touch sensor, wherein the control electronics uses an algorithm to determine the coordinates of the location of the touch in the touch region based on the touch information, and modifies the algorithm based on the measurable information.

6. A dynamic touch sensor system, comprising:

a touch that generates touch information in response to a touch and generates measurable information indicative of a given electrical characteristic in the touch sensor, the touch sensor comprising a substrate having a resistive touch region, a set of electrodes electrically coupled to the touch region, and a band framing the touch region and having a resistivity intermediate the resistivity of the electrodes and the resistivity of the touch region, wherein the band has a substantially non-uniform linear resistance, the band being continuous or quasi-continuous along at least a portion of its length and comprising an array of electrically conductive elements disposed on the substrate, the conductive elements having a spacing or size that varies along the length of the band; and

control electronics coupled to the electrodes for receiving the touch information and measurable information from the touch sensor, wherein the control electronics uses an algorithm to determine the coordinates of the location of the touch in the touch region based on the touch information, and modifies the algorithm based on the measurable information.

7. A touch sensor, comprising:

a substrate having a resistive touch region;

a set of electrodes electrically coupled to the touch region; and

a plurality of band segments framing the touch region and having a resistivity intermediate between the resistivity of the electrodes and the resistivity of the touch region,

wherein the electrodes are disposed between the bad segments, and at least one band segment comprises a continuous resistive background material and an array of electrically conductive elements disposed substantially perpendicularly along at least a lengthwise band portion of the at least one band segment in contact with the background material, the electrically conductive elements having a resistivity that is lower than the resistivity of the background material, the lengthwise band portion being quasi-continuous along its length.

8. The touch sensor of claim 7, wherein the resistive touch region is formed from the background material.

9. The touch sensor of claim 7, wherein the background material has a resistivity different from the resistivity of the touch region.

10. The touch sensor of claim 7, wherein the electrically conductive elements extend perpendicularly relative to the lengthwise band portion.

11. The touch sensor of claim 7, wherein the electrically conductive elements are generally arranged parallel to each other.

12. The touch sensor of claim 7, wherein the electrically conductive elements are composed of linear lines.

13. The touch sensor of claim 7, wherein the background material comprises a series of resistive segments alternately disposed between the conductive elements.

14. The touch sensor of claim 13, wherein each electrically conductive element has a fractional width defined by the dimension of the electrically conductive element along the lengthwise band portion over the sum of the dimension of the corresponding resistive segment along the lengthwise band portion and the dimension of the electrically conductive element along the lengthwise band portion.

15. The touch sensor of claim 14, wherein the fractional width is less than 0.9.

16. The touch sensor of claim 14, wherein the fractional width is between 0.2 and 0.8.

17. The touch sensor of claim 14, wherein the fractional width amongst the electrically conductive elements varies.

18. The touch sensor of claim 14, wherein the fractional width amongst the electrically conductive elements is uniform.

19. The touch sensor of claim 13, wherein the dimension of each of the resistive segments along the lengthwise band portion is less than 1 percent of the length of the at least one band segment.

20. The touch sensor of claim 7, wherein the continuous resistive background material and the array of electrically conductive elements are disposed along the entire length of the at least one band segment.

21. The touch sensor of claim 7, wherein the at least one band segment comprises the plurality of band segments.