Edge-coupled touch-sensitive apparatus

1. A touch-sensitive apparatus, comprising:

a light-transmissive panel having a front surface, an opposite rear surface, and a first side edge and a second side edge connecting the front surface and the rear surface;

a light emitter positioned on a first support structure, said light emitter configured to input light at a first side edge portion, wherein the first support structure is separate from the light-transmissive panel;

a detector positioned on a second support structure, said detector configured to receive light output through a second side edge portion;

a light-transmissive sheet laminated over the front surface of the light-transmissive panel, the light-transmissive sheet having a first portion extending beyond the first side edge of the light-transmissive panel, the first portion configured to cover the light emitter and a second portion extending beyond the second side edge of the light transmissive panel, the second portion configured to cover the detector;

a shielding element positioned between the first support structure and a lower surface of the light-transmissive sheet, the shielding element covering said light emitter, and the shielding element configured to block light having a wavelength range in which the light emitter outputs light;

wherein the lower surface of the light-transmissive sheet is in optical contact with the front surface of the light-transmissive panel, so as to allow input light to propagate between the light emitter and the detector through the light-transmissive panel and the light-transmissive sheet via total internal reflection between an upper surface of the light-transmissive sheet and the rear surface of the light-transmissive panel;

wherein at least a first reflection of the input light at the upper surface of the light-transmissive sheet and a second reflection at the rear surface of the light-transmissive panel are at critical angles resulting in total internal reflection of the input light between at least the first reflection and the second reflection; and

wherein the first reflection and the second reflection are consecutive reflections of the input light.

2. The touch-sensitive apparatus of claim 1 ,

wherein the first support structure is secured towards the lower surface of the light-transmissive sheet.

3. The touch-sensitive apparatus of claim 1 ,

wherein the first support structure is secured towards the rear surface of the light-transmissive panel.

4. The touch-sensitive apparatus of claim 2 , wherein said support structure is a printed circuit board.

5. The touch-sensitive apparatus of claim 2 , wherein said support structure is a flex film.

6. The touch-sensitive apparatus of claim 2 , wherein said support structure is an elongate strip along an extended portion of the side edge, and configured to support at least one of a plurality of emitters or a plurality of detectors.

7. The touch-sensitive apparatus of claim 1 , further comprising:

a side connecting element configured to secure at least one of said light emitter and said detector towards the side edge of the light-transmissive panel.

8. The touch-sensitive apparatus of claim 7 , wherein said side connecting element includes a transparent adhesive or silicon, and said side connecting element is configured to provide optical matching to the light-transmissive panel.

9. The touch-sensitive apparatus of claim 1 , wherein the shielding element is a rigid metal sheet member configured to reinforce the portion of the light-transmissive sheet extending beyond the side edge of the light-transmissive panel.

10. The touch-sensitive apparatus of claim 1 , wherein the shielding element covers an outer region of the front surface to suppress ambient light incident on the upper surface, within a wavelength range of use, from specularly reaching at least said detector.

11. The touch-sensitive apparatus of claim 1 , wherein the shielding element is non-transmissive to visible light.

12. The touch-sensitive apparatus of claim 1 , wherein a lower surface of the shielding element, which faces an outer region of the front surface of the light-transmissive panel, is specularly reflective within a wavelength range of use.

13. The touch-sensitive apparatus of claim 2 , wherein said support structure is attached to a lower surface of the shielding element.

14. The touch-sensitive apparatus of claim 1 , wherein the light-transmissive sheet includes a rigid layer.

15. The touch-sensitive apparatus of claim 14 , wherein the rigid layer is composed of the same material as the light-transmissive panel.

16. The touch-sensitive apparatus of claim 1 , further comprising:

a light coupling member arranged at the side edge, and configured to optically connect at least one of the light emitter and the detector to the light-transmissive panel.

17. The touch-sensitive apparatus of claim 16 , wherein the light coupling member includes at least one non-imaging, diffusively transmitting optical element arranged on the side edge of the light-transmissive panel;

the light emitter is configured to emit a beam of light onto the at least one non-imaging, diffusively transmitting optical element; and

the detector is configured to receive detection light generated by diffuse transmission as propagating light from within the light-transmissive panel impinges on the at least one non-imaging, diffusively transmitting optical element.

18. The touch-sensitive apparatus of claim 1 , wherein the light-transmissive panel is thicker than the light-transmissive sheet.

19. The touch-sensitive apparatus of claim 1 , wherein the light-transmissive panel overlays a display.