Bezel-less acoustic touch apparatus
An acoustic touch apparatus is provided that includes a substrate capable of propagating surface acoustic waves, such as Rayleigh-type or Love-type waves. The substrate has a front surface, a back surface, and a curved connecting surface formed between the front surface and the back surface. The apparatus also includes at least one acoustic wave transducer and at least one reflective array, the acoustic wave transducer and the reflective array behind the back surface of the substrate. The acoustic wave transducer is capable of transmitting or receiving surface acoustic waves to or from the reflective array. The reflective array is capable of acoustically coupling the surface acoustic waves to propagate from the back surface and across the front surface via the curved connecting surface. Various types of acoustic touch apparatus with edge sensitive touch functions can be provided, according to specific embodiments.
1. A method, comprising:
propagating surface acoustic waves on a substrate, said substrate having a touch surface, a back surface, and a curved connecting surface formed between said touch surface and said back surface;
transmitting surface acoustic waves from at least one acoustic wave transducer via at least one beam splitter comprising a plurality of deflecting elements to at least one reflective array disposed on said back surface, or receiving surface acoustic waves at said at least one acoustic wave transducer from said at least one reflective array disposed on said back surface via said at least one beam splitter; and
scattering said surface acoustic waves at said at least one reflective array, such that said scattered surface acoustic waves are propagated between said back surface and said touch surface via said curved connecting surface.
2. The method according to claim 1 , wherein said touch surface includes a nominal touch region and a peripheral region external to said nominal touch region, said peripheral region not covered by a bezel.
3. The method according to claim 2 , wherein said substrate propagates perturbations of said surface acoustic waves, said perturbations capable of detection to determine a coordinate of a touch on said nominal touch region, on said peripheral region or on said curved connecting surface.
4. The method according to claim 3 , wherein said perturbations are further capable of detection to generate touch coordinate data for said peripheral region or said curved connecting surface and initiate an edge sensitive touch function.
5. The method according to claim 4 , further comprising providing a plurality of edge sensitive touch functions corresponding to different coordinates on said peripheral region or on said curved connecting surface.
6. The method according to claim 4 , further comprising providing an icon indicating said edge touch sensitive function.
7. The method according to claim 1 , wherein said at least one beam splitter is configured to deflect a portion of said surface acoustic waves between said at least one acoustic wave transducer and said at least one reflective array.
8. The method according to claim 7 , further comprising disposing said at least one beam splitter on said back surface.
9. The method according to claim 1 , wherein said substrate has a thickness T and said curved connecting surface joins said touch surface and said back surface via at least one curved section having a radius R ranging between about T/3 and about T/16.
10. The method according to claim 1 , further comprising coupling said at least one acoustic wave transducer and said at least one reflective array to said back surface via an acoustically benign layer on said back surface.
11. The method according to claim 10 , wherein said acoustically benign layer comprises an inorganic material.
12. The method according to claim 10 , wherein said acoustically benign layer is opaque or translucent.
13. The method according to claim 2 , further comprising:
providing at least one conductive electrode disposed near said peripheral region or said curved connecting surface.
14. The method according to claim 13 , further comprising disposing said at least one conductive electrode on said back surface.
15. The method according to claim 14 , wherein said at least one conductive electrode comprises reflective elements of said reflective array and a conductive lead coupling said reflective elements, wherein said at least one conductive electrode and said reflective elements are formed on said back surface via an acoustically benign layer.
16. The method according to claim 1 , further comprising providing a second reflective array, wherein said second reflective array and said at least one reflective array share a common reflector element.
17. The method according to claim 1 , further comprising providing an acoustically attenuating and optically transparent layer at said back surface.
18. The method according to claim 1 , wherein said at least one reflective array is disposed opposite said touch surface on said back surface.
19. The method according to claim 2 , wherein said at least one reflective array is disposed on said peripheral region of said back surface.
20. The method according to claim 1 , wherein said at least one reflective array and said at least one acoustic wave transducer are both disposed on said back surface.