Thin couplers and reflectors for sensing waveguides
An optical touch-sensitive device is able to determine the locations of multiple simultaneous touch events. The optical touch-sensitive device can include an optical waveguide, an emitter, and an emitter coupler. The emitter produces optical beams, and the emitter coupler is on a surface of the waveguide and is configured to direct at least some of the optical beams to propagate via total internal reflection (TIR) through the waveguide as coupled optical beams. Touches on the top surface of the waveguide disturb the coupled optical beams, and the touch-sensitive device determines touch events based on the disturbances.
1. An optical touch-sensitive device comprising:
an optical waveguide extending over a surface of the touch-sensitive device, the waveguide having a top surface and a bottom surface;
an emitter coupled to the waveguide and configured to produce optical beams, wherein the emitter coupler is attached to the top surface of the waveguide; and
an emitter coupler, coupled to the waveguide, including optical structures configured to direct at least some of the optical beams to propagate via total internal reflection (TIR) through the waveguide according to a predetermined pattern as coupled optical beams, wherein touches on the top surface of the waveguide disturb at least some of the coupled optical beams, the touch-sensitive device determining touch events based on the disturbances, wherein the emitter coupler is a portion of a thin film coupled to the waveguide, the thin film having a thickness less than or equal to 500 micrometers, wherein the thin film comprises a protective topcoat, a decorative layer, a metallization layer, and a cured embossed polymer, the cured embossed polymer attached to the top surface of the waveguide,
wherein the predetermined pattern includes optical beams that propagate at a first elevation angle relative to the top surface of the waveguide and optical beams that propagate at a second elevation angle relative to the top surface of the waveguide.
2. The optical touch-sensitive device of claim 1 , further comprising:
a detector coupled to the waveguide; and
a detector coupler on a surface of the waveguide and configured to redirect at least some of the coupled optical beams out of the waveguide and towards the detector.
3. The optical touch-sensitive device of claim 2 , wherein the emitter is an array of optical sources and the detector is an array of sensor elements.
4. The optical touch-sensitive device of claim 2 , wherein an optical beam directed by an optical structure of the emitter coupler to propagate at the first elevation angle is received by the detector coupler at a modified elevation angle relative to the top surface of the waveguide, wherein the modified elevation angle is different than the first elevation angle.
5. The optical touch-sensitive device of claim 1 , further comprising:
a reflector on a surface of the waveguide configured to redirect at least some of the coupled optical beams.
6. The optical touch-sensitive device of claim 5 , wherein the reflector is on the top surface of the waveguide.
7. The optical touch-sensitive device of claim 5 , wherein the reflector is on the bottom surface of the waveguide.
8. The optical touch-sensitive device of claim 5 , wherein the reflector is on or adjacent to a side surface of the waveguide.
9. The optical touch-sensitive device of claim 5 , wherein the reflector increases or decreases the elevation angle of an optical beam directed by an optical structure of the emitter coupler to propagate at the first elevation angle.
10. The optical touch-sensitive device of claim 1 , wherein the waveguide comprises a polymer film attached to a top surface of a glass or polymer layer by an adhesive layer.
11. The optical touch-sensitive device of claim 10 , wherein the coupled optical beams only propagate through the polymer film.
12. The optical touch-sensitive device of claim 1 , wherein the emitter coupler is attached to the bottom surface of the waveguide.
13. The optical touch-sensitive device of claim 1 , wherein the emitter coupler is further configured to redirect a first subset of the coupled optical beams with a first footprint and a second subset of the coupled optical beams with a second footprint.
14. The optical touch-sensitive device of claim 1 , wherein the emitter is tilted at an angle relative to a normal of the top surface or the bottom surface of the waveguide.
15. An optical touch-sensitive device comprising:
an optical waveguide extending over a surface of the touch-sensitive device, the waveguide having a top surface and a bottom surface;
an emitter coupled to the waveguide and configured to produce optical beams, wherein the emitter coupler is attached to the top surface of the waveguide; and
an emitter coupler, coupled to the waveguide, including optical structures configured to direct at least some of the optical beams to propagate via total internal reflection (TIR) through the waveguide according to a predetermined pattern as coupled optical beams, wherein touches on the top surface of the waveguide disturb at least some of the coupled optical beams, the touch-sensitive device determining touch events based on the disturbances, wherein the emitter coupler is a portion of a thin film coupled to the waveguide, the thin film having a thickness less than or equal to 500 micrometers, wherein the thin film comprises a protective topcoat, a decorative layer, an air gap layer, and a cured embossed polymer, the cured embossed polymer attached to the top surface of the waveguide,
wherein the predetermined pattern includes optical beams that propagate at a first elevation angle relative to the top surface of the waveguide and optical beams that propagate at a second elevation angle relative to the top surface of the waveguide.
16. The optical touch-sensitive device of claim 15 , further comprising:
a detector coupled to the waveguide; and
a detector coupler on a surface of the waveguide and configured to redirect at least some of the coupled optical beams out of the waveguide and towards the detector.
17. The optical touch-sensitive device of claim 16 , wherein an optical beam directed by an optical structure of the emitter coupler to propagate at the first elevation angle is received by the detector coupler at a modified elevation angle relative to the top surface of the waveguide, wherein the modified elevation angle is different than the first elevation angle.
18. The optical touch-sensitive device of claim 15 , further comprising:
a reflector on a surface of the waveguide configured to redirect at least some of the coupled optical beams.
19. The optical touch-sensitive device of claim 18 , wherein the reflector increases or decreases the elevation angle of an optical beam directed by an optical structure of the emitter coupler to propagate at the first elevation angle.