Sensing device

• US 8,803,813 B2
• Filed: 05/10/2006
• Issued: 08/12/2014
• Est. Priority Date: 05/10/2006
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: XiaoPing, Jiang, Hua, Liu
• Primary Examiner(s): PATEL, PREMAL R
• Application Number:
  US11/432,130
• Publication Number:
  US 20070262962A1
• Time in Patent Office: 3,016 Days
• Field of Search: 345173-178, 178 1801- 1809
• US Class Current: 345/173
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/03548 Sliders, in which the moving part moves in a plane
• 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 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

An apparatus and method for reducing charge time and power consumption of a sensor element of a sensing device. The apparatus may include a sensor element of a sensing device that has a surface area of conductive material and one or more gaps in the conductive material. The sensor element may include a plurality of evenly-spaced, parallel bars of conductive material and a plurality of interconnect lines coupled to the evenly-spaced, parallel bars to form the one or more gaps in the conductive material of the sensor element.

Claims

1. An apparatus, comprising:

a sensor element of a row or column of sensor elements of a sensor array of a sensing device, the sensor element having two or more gaps between electrically connected portions of the same sensor element, the two or more gaps extending in a conductive material of a surface area of the sensor element from the periphery of the sensor element toward the center;

wherein the sensor element is electrically connected to a single conductive trace that connects the row or column of sensor elements; and

an interconnect line, within the sensor element, that couples the electrically connected portions of the same sensor element to each other, wherein each of the electrically connected portions of the same sensor element branches from the interconnect line, and wherein each of the electrically connected portions of the same sensor element is wider than the interconnect line.

2. The apparatus of claim 1, wherein the sensor element is a substantially diamond shape.

3. The apparatus of claim 1, wherein each of the two or more gaps of the sensor element is a substantially rectangular shape.

4. The apparatus of claim 1, wherein the sensing device is at least one of a touch-sensor pad, a touch-sensor slider, or a touch-sensor button.

5. The apparatus of claim 1, further comprising a processing device coupled to the sensing device, wherein the processing device is operable to detect a presence of a conductive object on the sensing device.

6. The apparatus of claim 1, wherein the two or more gaps are substantially parallel to each other along substantially their entire lengths in the sensor element.

7. A method, comprising:

forming a sensor element of a row or column of sensor elements of a sensor array;

wherein the sensor element is electrically connected to a single conductive trace that connects the row or column of sensor elements;

generating two or more gaps between electrically connected portions of the sensor element, the two or more gaps extending in a conductive material of a surface area of the sensor element from the periphery of the sensor element toward the center; and

coupling, within the sensor element, an interconnect line to the electrically connected portions of the sensor element, wherein each of the electrically connected portions of the sensor element branches from the interconnect line, and wherein each of the electrically connected portions of the sensor element is wider than the interconnect line.

8. The method of claim 7, wherein generating the two or more gaps in the sensor element comprises using additive photolithography techniques.

9. The method of claim 8, wherein the additive photolithography techniques comprise:

depositing the conductive material on an insulation layer to form the sensor element;

depositing a photoresist layer on the conductive material;

exposing the photoresist layer to light through a photomask, having a predetermined pattern, wherein the pre-determined pattern is configured to form the two or more gaps in the conductive material of the sensor element, and wherein the photoresist layer deposited on the two or more gaps is not exposed to the light; and

etching the photoresist layer to remove the photoresist layer and the conductive material of the two or more gaps, wherein etching is configured to reduce a total surface area of the sensor element.

10. The method of claim 7, wherein generating the two or more gaps in the sensor element comprises using subtractive photolithography techniques.

11. The method of claim 10, wherein the subtractive photolithography techniques comprise:

depositing the conductive material on an insulation layer to form the sensor element;

depositing a photoresist layer on the conductive material;

exposing the photoresist layer to light through a photomask, having a predetermined pattern, wherein the pre-determined pattern is configured to form an inverse of the pre-determined pattern having two or more gaps in the conductive surface of the sensor element, and wherein the photoresist layer deposited on the two or more gaps is exposed to the light; and

etching the photoresist layer to remove the photoresist layer and the conductive material of the sensing area not exposed to the light, wherein etching is configured to reduce a total surface area of the sensor element.

12. The method of claim 11, wherein exposing the photoresist layer comprises at least one of directly imaging the pre-determined pattern of the photomask onto the photoresist layer, or projecting an image of the photomask onto the photoresist layer to produce the pre-determined pattern on the photoresist layer.

13. The method of claim 7, wherein forming the sensor element comprises using impurity doping techniques.

14. The method of claim 7, wherein generating the two or more gaps in the sensor element comprises filling the two or more gaps with at least one of coating material or dielectric material.

15. An apparatus, comprising:

a sensing device comprising a plurality of sensor elements of a plurality of row or a columns of sensor elements arranged in an array;

means for reducing charge time of each sensor element of the plurality of sensor elements, wherein the means for reducing charge comprises two or more gaps between electrically connected portions of the sensor element, wherein the two or more gaps extend in a conductive material of a surface area of the sensor element from the periphery of the sensor element toward the center, and wherein the sensor element is electrically connected to a single conductive trace that connects a row or column of sensor elements; and

means for connecting the electrically connected portions of the sensor element to each other, wherein each of the electrically connected portions of the sensor element branches from the means for connecting, and wherein each of the electrically connected portions of the sensor element is wider than the means for connecting.

16. The apparatus of claim 15, further comprising means for reducing power consumption of the sensing device.