Illumination device with metalized light-turning features

• US 8,810,528 B2
• Filed: 12/27/2010
• Issued: 08/19/2014
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Bita, Ion, Dhanens, Stephen P., Gousev, Evgeni P., Narayanan, Kollengode S.
• Primary Examiner(s): Bolotin, Dmitriy
• Application Number:
  US12/979,196
• Publication Number:
  US 20110157093A1
• Time in Patent Office: 1,331 Days
• Field of Search: 345173-179, 345/156, 345/102, 178/18.06, 359/290, 349 61- 71, 362615-629
• US Class Current: 345/173
• 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

This disclosure provides systems, methods and apparatus for a front illumination device with metalized light-turning features. 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 conductor formed on a light-turning feature, and extending into a recess of the light turning feature; and

a touch-sensing electrode system capable of sensing a change to an electric field of the conductor,

wherein the touch-sensing electrode s stem includes a first electrode extending in one direction and a second electrode extending in another, non-parallel direction,

wherein the first electrode has a gap with two sides formed to prevent the intersection of the first and the second electrodes, the gap breaking the first electrode into a first side and a second side, and

wherein the first and second electrodes are formed on a single surface.

2. The illumination device of claim 1, wherein the conductor is formed on a faceted feature on a surface of the light guide.

3. The illumination device of claim 1, wherein the conductor is masked in order to reduce reflections of ambient light from the conductor.

4. The illumination device of claim 3, wherein the conductor is masked with an interferometric structure.

5. The illumination device of claim 4, wherein the interferometric structure is configured to be more reflective of light striking a bottom surface of the interferometric structure than light striking a top surface of the interferometric structure.

6. The illumination device of claim 1, wherein the electrode system is capable of determining a location in an x-y plane of the change to the electric field of the conductor.

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

a display which can be illuminated by the light guide;

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

a memory device that is configured to communicate with the processor.

8. The illumination device of claim 7, further comprising a driver circuit configured to send at least one signal to the display.

9. The illumination device of claim 8, further comprising a controller configured to send at least a portion of the image data to the driver circuit.

10. The illumination device of claim 7, further comprising an image source module configured to send the image data to the processor.

11. The illumination device of claim 10, wherein the image source module includes at least one of a receiver, transceiver, or transmitter.

12. The illumination device of claim 7, further comprising:

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

13. The illumination device of claim 1, wherein

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

and

the light-turning feature is formed in the light-turning layer.

14. The illumination device of claim 1, wherein the first side of the first electrode is electrically connected to the second side of the first electrode across the gap through a conductive bridge and vias formed on both sides of the gap.

15. The illumination device of claim 14, wherein the first and second electrodes include transparent conductors.

16. The illumination device of claim 14, wherein the conductive bridge is formed on a level below the surface of the first and second electrodes.

17. The illumination device of claim 14, wherein the conductive bridge includes a reflective conductor.

18. The illumination device of claim 14, wherein the vias include a reflective conductor.

19. The illumination device of claim 18, wherein the vias are light-turning features configured to direct light downward out of the light guide.

20. The illumination device of claim 1, wherein the first and second electrodes are formed in two different layers.

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

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

23. The illumination device of claim 1, wherein the light guide has light-turning features that are not in electrical communication with the touch-sensing electrode system.

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

25. The illumination device of claim 24, wherein the reflective display includes display elements including interferometric modulators.

26. The illumination device of claim 1, wherein the change to the electric field is induced by the proximity of a body.

27. The illumination device of claim 26, wherein the body is electrically conductive.

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

patterning a first electrode extending in one direction and a second electrode extending in another, non-parallel direction on a substrate;

patterning a gap with two sides in the first electrode formed to prevent the intersection of the first and second electrodes, the gap breaking the first electrode into a first side and a second side;

depositing an index-matched turning layer on the substrate to form a light guide;

taper etching a light-turning feature in the turning layer to form a facet;

depositing a reflective conductor on surfaces of the facet, and extending into a recess of the facet;

etching the light-turning feature for electrically connecting to one of the first and second sides of the first electrode; and

electrically connecting the conductor to an electrode system capable of sensing a change to an electric field of the conductor, the electrode system including the first and second electrodes.

29. The method of manufacturing the illumination device with integrated touch-sensing capability of Claim 28, further comprising

depositing a conductive bridge in a layer over the turning layer, thereby electrically bridging the first side and the second side of the first electrode through the conductor formed on the light-turning feature and the conductive bridge.

30. The method of claim 28, wherein the change to the electric field is induced by the proximity of a body.

31. The method of claim 30, wherein the body is electrically conductive.

32. The method of claim 28, wherein sensing the change to the electric field includes sensing a change to a capacitance of the conductor.

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

depositing an index-matched turning layer on a substrate;

taper etching the light-turning feature in the turning layer to form a facet;

depositing a reflective conductor on surfaces of the facet, and extending into a recess of the facet;

patterning a first electrode extending in one direction and a second electrode extending in another, non-parallel direction on the turning layer;

patterning a gap with two sides in the first electrode formed to prevent the intersection of the first and the second electrodes, the gap breaking the first electrode into a first side and a second side;

etching the light-turning feature for electrically connecting to one of the first and second sides of the first electrode; and

electrically connecting the conductor to an electrode system capable of sensing a change to an electric field of the conductor, the electrode system including the first and second electrodes.

34. The method of manufacturing the illumination device with integrated touch-sensing capability of claim 33, further comprising

depositing a conductive bridge in a layer below the turning layer thereby electrically bridging the first side and the second side of the first electrode through the conductor formed on the light-turning feature and the conductive bridge.

35. An illumination device comprising:

a light guide having a conductor, formed on a light-turning facet, and extending into a recess of a light turning feature,

a first electrode extending in one direction and a second electrode extending in another, non-parallel direction,

wherein the first electrode has a gap with two sides formed to prevent the intersection of the first and second electrodes, the gap breaking the first electrode into a first side and a second side,

wherein the first and second electrodes are formed on a single surface, and

wherein the conductor formed on the light-turning facet is electrically connected to an electronic system.

36. The illumination device of claim 35, wherein the electronic system is capable of detecting the proximity of an electrically conductive body.

37. The illumination device of claim 36, wherein the conductor forms electrodes in a capacitive touch sensor system.

38. The illumination device of claim 35, wherein the conductor constitutes a layer in a stack of materials forming an interferometric structure for reducing reflections.

39. The illumination device of claim 35, wherein the conductor extends across an entire display surface.