Touchscreen using oriented microscopic linear conductive elements

• US 20090046078A1
• Filed: 08/14/2007
• Published: 02/19/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Kent, Joel C.
• Granted Patent: US 8,212,792 B2
• Time in Patent Office: Days
• US Class Current: 345/176
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• 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: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix

Abstract

A cover sheet assembly is provided for a touchscreen system. The cover sheet assembly includes an insulating layer having a surface configured to be disposed over an electrically conductive area of a substrate of the touchscreen system. An electrically conductive material is disposed on at least a portion of the insulating layer surface. The electrically conductive material includes a plurality of microscopic linear conductive elements arranged in a pattern that is oriented with respect to a first direction of a first polarization of light such that the electrically conductive material is more transparent to the first polarization of light than to a second polarization of light that is polarized in a second direction that is perpendicular to the first direction.

Claims

1. A cover sheet assembly for a touchscreen system, said cover sheet assembly comprising:

an insulating layer having a surface configured to be disposed over an electrically conductive area of a substrate of the touchscreen system; and

an electrically conductive material disposed on at least a portion of the insulating layer surface, the electrically conductive material comprising a plurality of microscopic linear conductive elements arranged in a pattern that is oriented with respect to a first direction of a first polarization of light such that the electrically conductive material is more transparent to the first polarization of light than to a second polarization of light that is polarized in a second direction that is perpendicular to the first direction.

2. The cover sheet assembly according to claim 1, wherein the pattern of the plurality of microscopic linear conductive elements is oriented in an alignment direction that is more aligned with the second direction of the second polarization of light than the first direction of the first polarization of light.

3. The cover sheet assembly according to claim 1, wherein the pattern of the plurality of microscopic linear conductive elements is oriented in an alignment direction that is approximately aligned with the second direction of the second polarization of light.

4. The cover sheet assembly according to claim 1, wherein the pattern of the plurality of microscopic linear conductive elements is oriented with respect to the first direction of the first polarization of light such that the electrically conductive material is at least 1% more transparent to the first polarization of light than to the second polarization of light.

5. The cover sheet assembly according to claim 1, wherein the microscopic linear conductive elements comprise at least one of an electrically conductive polymer, carbon nanoparticles, and metal nanoparticles.

6. A substrate assembly for a touchscreen system, said substrate assembly comprising:

a substrate; and

an electrically conductive material disposed on at least a portion of a surface of the substrate to provide an electrically conductive touch area on the substrate, the electrically conductive material comprising a plurality of microscopic linear conductive elements arranged in a pattern that is oriented with respect to a first direction of a first polarization of light such that the electrically conductive material is more transparent to the first polarization of light than to a second polarization of light that is polarized in a second direction that is perpendicular to the first direction.

7. The substrate assembly according to claim 6, wherein the pattern of the plurality of microscopic linear conductive elements is oriented in an alignment direction that is more aligned with the second direction of the second polarization of light than the first direction of the first polarization of light.

8. The substrate assembly according to claim 6, wherein the pattern of the plurality of microscopic linear conductive elements is oriented in an alignment direction that is approximately aligned with the second direction of the second polarization of light.

9. The substrate assembly according to claim 6, wherein the pattern of the plurality of microscopic linear conductive elements is oriented with respect to the first direction of the first polarization of light such that the electrically conductive material is at least 1% more transparent to the first polarization of light than to the second polarization of light.

10. The substrate assembly according to claim 6, wherein the microscopic linear conductive elements comprise at least one of an electrically conductive polymer, carbon nanoparticles, and metal nanoparticles.

11. The substrate assembly according to claim 6, further comprising an insulating layer positioned over the touch area on the substrate, a surface of the insulating layer facing the substrate being disposed directly on the electrically conductive material on the substrate surface.

12. The substrate assembly according to claim 6, further comprising a cover sheet positioned over the touch area on the substrate, the cover sheet comprising an insulating layer and a second electrically conductive material disposed on at least a portion of a surface of the insulating layer that generally faces the substrate.

13. The substrate assembly according to claim 12, wherein the plurality of microscopic linear conductive elements are a first plurality of microscopic linear conductive elements and the pattern is a first pattern, and the second electrically conductive material comprises a second plurality of microscopic linear conductive elements arranged in a second pattern that is oriented with respect to the first direction of the first polarization of light such that the second electrically conductive material is more transparent to the first polarization of light than to the second polarization of light.

14. The substrate assembly according to claim 13, wherein the first and second electrically conductive materials are substantially the same material.

15. A substrate assembly for a touchscreen system, said substrate assembly comprising:

a substrate having a first surface and a second surface opposite the first surface; and

a first electrically conductive material disposed on at least a portion of the first surface of the substrate to provide an electrically conductive touch area on the substrate;

a second electrically conductive material disposed on at least a portion of the second surface of the substrate, the second electrically conductive material comprising a plurality of microscopic linear conductive elements arranged in a pattern that is oriented with respect to a first direction of a first polarization of light such that the second electrically conductive material is more transparent to the first polarization of light than to a second polarization of light that is polarized in a second direction that is perpendicular to the first direction.

16. The substrate assembly according to claim 15, wherein the pattern of the plurality of microscopic linear conductive elements is oriented in an alignment direction that is more aligned with the second direction of the second polarization of light than the first direction of the first polarization of light.

17. The substrate assembly according to claim 15, wherein the pattern of the plurality of microscopic linear conductive elements is oriented in an alignment direction that is approximately aligned with the second direction of the second polarization of light.

18. The substrate assembly according to claim 15, wherein the pattern of the plurality of microscopic linear conductive elements is oriented with respect to the first direction of the first polarization of light such that the electrically conductive material is at least 1% more transparent to the first polarization of light than to the second polarization of light.

19. The substrate assembly according to claim 15, wherein the microscopic linear conductive elements comprise at least one of an electrically conductive polymer, carbon nanoparticles, and metal nanoparticles.

20. The substrate assembly according to claim 15, wherein the plurality of microscopic linear conductive elements are a second plurality of microscopic linear conductive elements and the pattern is a second pattern, and the first electrically conductive material comprises a first plurality of microscopic linear conductive elements arranged in a first pattern that is oriented with respect to the first direction of the first polarization of light such that the first electrically conductive material is more transparent to the first polarization of light than to the second polarization of light.