Touchpad having Single Layer Layout

• US 20080136787A1
• Filed: 09/14/2007
• Published: 06/12/2008
• Est. Priority Date: 12/11/2006
• Status: Abandoned Application

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Lee, Wen-Kai, YEH, I-HAU
• Application Number:
  US11/855,266
• Publication Number:
  US 20080136787A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A touchpad has a substrate; and a single trace layer formed on the substrate. The single trace layer has a single trace layer including rows of conductive traces. Each conductive trace has a gradual change resistance according to a distance far away from one end.

Claims

1. A touchpad comprising:

a substrate; and

a single trace layer formed on the substrate, which comprises a single trace layer comprising rows of conductive traces;

wherein each conductive trace has a resistance increasing or decreasing according to a distance far away from one end.

2. The touchpad as claimed in claim 1, wherein the conductive traces have geometric proportion increasing or decreasing resistances.

3. The touchpad as claimed in claim 1, wherein the conductive traces have inequality proportion increasing or decreasing resistances.

4. The touchpad as claimed in claim 1, further comprising a touchpad controller connected with the single trace layer.

5. The touchpad as claimed in claim 4, wherein the touchpad controller is connected to a beginning end or a tail end of each conductive trace.

6. The touchpad as claimed in claim 5, wherein each conductive trace is scanned by the touchpad controller from the beginning end or the tail end thereof.

7. The touchpad as claimed in claim 4, wherein the touchpad controller is connected to a beginning end and a tail end of each conductive trace.

8. The touchpad as claimed in claim 7, wherein each conductive trace is scanned by the touchpad controller from the beginning end and the tail end thereof, respectively.

9. The touchpad as claimed in claim 4, wherein two connecting ends of the touchpad controller with two adjacent conductive traces are respectively disposed at two opposite sides of the touchpad.

10. The touchpad as claimed in claim 1, wherein the conductive traces can be made from Indium-Tin Oxide (ITO), flexible printed circuit (FPC) or printed circuit board (PCB) or Membrane.

11. The touchpad as claimed in claim 1, wherein each conductive trace comprises number n cells serial connecting together.

12. The touchpad as claimed in claim 11, wherein the conductive traces having increasing resistance can be attained by controlling the width of each cell of the trace.

13. The touchpad as claimed in claim 11, wherein the conductive traces having increasing resistance can be attained by coating different resistance at each cell of the trace.

14. The touchpad as claimed in claim 1, further comprising a protective overlayer, a compliant material, and a conductive layer.

15. The touchpad as claimed in claim 4, wherein the touchpad controller detects the capacitance change measured by the single trace layer.

16. The touchpad as claimed in claim 4, wherein the touchpad controller detects the energy change or the time constant change produced by increasing or decreasing resistance of each conductive trace.

17. The touchpad as claimed in claim 4, wherein the touchpad controller detects the concrete contact position according to the capacitance change and the energy change, or the capacitance change and the time constant change.

19. The touchpad as claimed in claim 1, wherein the rows of conductive traces extend along a predetermined direction.

18. A touchpad comprising:

a substrate; and

a single trace layer formed on the substrate, which comprises a single trace layer comprising rows of conductive traces;

wherein each conductive trace has a gradual change resistance according to a distance far away from one end.