US 11,740,741 B2
Optical coupling in touch-sensing systems
Håkan Bergström, Torna Hällestad (SE); and Aleksander Kocovski, Malmö (SE)
Assigned to FlatFrog Laboratories AB, Lund (SE)
Filed by FlatFrog Laboratories AB, Lund (SE)
Filed on Sep. 19, 2022, as Appl. No. 17/947,919.
Application 17/947,919 is a continuation of application No. 17/216,219, filed on Mar. 29, 2021, granted, now 11,474,644.
Application 17/216,219 is a continuation of application No. 16/313,820, granted, now 10,963,104, issued on Mar. 30, 2021, previously published as PCT/EP2018/052757, filed on Feb. 5, 2018.
Claims priority of application No. 17154898 (EP), filed on Feb. 6, 2017.
Prior Publication US 2023/0080260 A1, Mar. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 3/00 (2006.01); G06F 3/042 (2006.01)
CPC G06F 3/0428 (2013.01) [G06F 3/0421 (2013.01); G06F 2203/04107 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A touch sensing apparatus, comprising:
a light transmissive panel that defines a touch surface, an opposite rear surface, and panel sides extending between the touch surface and rear surface, the panel sides defining a perimeter of the light transmissive panel;
a plurality of light emitters and detectors arranged along the perimeter and adjacent the panel sides; and
a light guide arranged along the perimeter and comprising a light guide element;
wherein the light emitters are arranged to emit a respective beam of light onto the light guide so as to generate propagating light that propagates above the touch surface,
wherein the light detectors are arranged to receive detection light generated as said propagating light impinges on the light guide,
wherein said propagating light is specularly reflected by the light guide, and
wherein the light guide element comprises a recess or protrusion for interlocking with a correspondingly mating locking surface of a frame element of the touch sensing apparatus.