Illumination device with metalized light-turning features

• US 9,817,534 B2
• Filed: 10/22/2015
• Issued: 11/14/2017
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Inventors: Bita, Ion, Dhanens, Stephen P., Gousev, Evgeni P., Narayanan, Kollengode S.
• Primary Examiner(s): Bolotin, Dmitriy
• Application Number:
  US14/920,242
• Publication Number:
  US 20160041656A1
• Time in Patent Office: 754 Days
• Field of Search: 345173-179, 178 1801- 1811, 359290, 349 61- 71, 362615-629
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 6/0045 by shaping at least a portion of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G02F 1/225 in an optical waveguide structure
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

In one aspect, an illumination device with integrated touch sensor capability includes a light guide having a metalized light-turning feature and an electrode system for sensing changes to the capacitance between electrodes in the electrode system induced by the proximity of an electrically conductive body, such as a human finger. The metalized light-turning features may be electrically connected to and/or part of the electrode system.

Claims

1. An illumination device with integrated touch-sensing capability, comprising:

a light guide having a plurality of light-turning features defined by recesses in a surface of the light guide;

a plurality of spaced-apart conductors including a reflective metallic layer, each of the plurality of spaced-apart conductors extending in a corresponding one of the recesses; and

touch-sensing electronics capable of sensing a change to an electric field of a conductor of the plurality of conductors.

2. The illumination device of claim 1, wherein each of the plurality of spaced-apart conductors resides on a same level as others of the plurality of spaced-apart conductors.

3. The illumination device of claim 1, wherein the recesses extend partially through the light guide.

4. The illumination device of claim 1, wherein surfaces of the recesses include facets, wherein the conductors reside on the facets.

5. The illumination device of claim 1, wherein each of the conductors is coated with a reflection reducing structure to reduce reflections of ambient light from the corresponding conductor.

6. The illumination device of claim 5, wherein the reflection reducing structure is an interferometric structure, wherein the interferometric structure includes a corresponding one of the plurality of conductors, a spacer layer, and an absorber layer.

7. The illumination device of claim 6, wherein the interferometric structure is configured to be more reflective of light striking the corresponding conductor than light striking the absorber layer.

8. The illumination device of claim 1, wherein:

the light guide includes a light-turning layer on a substrate; and

the plurality of light-turning features extend in the light-turning layer.

9. The illumination device of claim 1, wherein the touch-sensing electronics is capable of determining a location in an x-y plane of the change to the electric field of each one of the plurality of conductors.

10. The illumination device of claim 1, wherein the touch-sensing electronics is capable of sensing a change to a mutual capacitance.

11. The illumination device of claim 1, wherein the touch-sensing electronics is capable of sensing a change to a self capacitance.

12. The illumination device of claim 1, wherein the change to the electric field is induced by the proximity of an electrically conductive body.

13. The illumination device of claim 1, wherein the light guide is over a reflective display.

14. The illumination device of claim 13, wherein the reflective display includes display elements including interferometric modulators.

15. The illumination device of claim 1, further comprising:

a display which can be illuminated by the light guide;

a processor configured to communicate with the display, the processor being configured to process image data; and

a memory device configured to communicate with the processor.

16. The illumination device of claim 15, wherein the display is rearward of the light guide.

17. The illumination device of claim 15, further comprising:

a driver circuit configured to send at least one signal to the display; and

a controller configured to send at least a portion of the image data to the driver circuit.

18. The illumination device of claim 15, further comprising:

an image source module configured to send the image data to the processor, wherein the image source module includes at least one of a receiver, transceiver, and transmitter.

19. The illumination device of claim 15, further comprising:

an input device configured to receive input data and to communicate the input data to the processor.

20. A method of manufacturing an illumination device with integrated touch-sensing capability, comprising:

providing a light guide having a plurality of light-turning features defined by recesses in a surface of the light guide;

depositing a plurality of spaced-apart conductors, each including a reflective metallic layer on surfaces of a corresponding light-turning feature in the light guide; and

electrically connecting the conductors to touch-sensing electronics capable of sensing a change to an electric field of a conductor of the plurality of conductors.

21. The method of claim 20, wherein depositing a plurality of spaced-apart conductors includes depositing each of the plurality of spaced-apart conductors on a same level.

22. The method of claim 20, wherein the recesses extend partially through the light guide.

23. The method of claim 20, wherein providing the light guide includes taper etching each of the light-turning features on the light guide to form facets.

24. The method of claim 20, wherein providing the light guide includes depositing an index-matched turning layer on a substrate and taper etching the light-turning features in the turning layer.

25. The method of claim 20, further comprising providing a display adjacent the light guide such that the light guide is configured to illuminate the display.

26. The method of claim 25, wherein the plurality of light-turning features are forward of the display and configured to direct light rearwards toward the display.