Optical waveguide for touch panel
An optical waveguide for a touch panel which includes a planar base; light emitting cores and light incident cores provided on a surface of the base; and an over-cladding layer covering the cores. The light emitting core has a first lens portion provided at the end thereof for suppressing lateral divergence of the emitted light beam, the over-cladding layer has a second lens portion provided in an edge portion thereof covering the end of the light emitting core for suppressing vertical divergence of the emitted light beam, the over-cladding layer has a third lens portion provided in an edge portion thereof covering the end of the light incident core for vertically converging the incident light beam, and the light incident core has a fourth lens portion provided at the end thereof for further laterally converging the incident light beam.
1. A touch panel optical waveguide to be disposed along a periphery of a display screen of a display of a touch panel, the touch panel optical waveguide comprising:
a planar base;
cores of uniform thickness provided on a surface of the base; and
an over-cladding layer covering the cores;
the cores including a light emitting core of uniform thickness having an end positioned on one side of the display screen of the display for emitting a light beam, and a light incident core of uniform thickness having an end positioned on the other side of the display screen of the display for receiving a light beam incident thereon;
wherein the light emitting core has a first lens portion provided at the end thereof for suppressing lateral divergence of the emitted light beam;
wherein the over-cladding layer has a second lens portion provided in an edge portion thereof covering the end of the light emitting core for suppressing vertical divergence of the emitted light beam transmitted through the first lens portion;
wherein the over-cladding layer has a third lens portion provided in an edge portion thereof covering the end of the light incident core for vertically converging the incident light beam;
wherein the light incident core has a fourth lens portion provided at the end thereof for further laterally converging the incident light beam transmitted through the third lens portion.
2. The touch panel optical waveguide as set forth in claim 1 , wherein the planar base is a base plate formed with a thin metal film or an under-cladding layer.
3. A band-shaped touch panel optical waveguide to be disposed along a periphery of a display of a touch panel, the touch panel optical waveguide comprising:
a light-transmissive under-cladding layer;
cores of uniform thickness provided on a surface of the under-cladding layer; and
an over-cladding layer covering the cores;
the cores including a light emitting core of uniform thickness having an end positioned on one side of the display for emitting a light beam, and a light incident core of uniform thickness having an end positioned on the other side of the display for receiving a light beam incident thereon;
wherein the light emitting core has a lens portion A provided at the end thereof for suppressing lateral divergence of the emitted light beam;
wherein a first reflective layer which suppresses vertical divergence of the emitted light beam transmitted through the lens portion A is provided on a surface of an edge portion of the over-cladding layer covering the end of the light emitting core;
wherein a second reflective layer which vertically converges the incident light beam is provided on a surface of an edge portion of the over-cladding layer covering the end of the light incident core;
wherein the light incident core has a lens portion B provided at the end thereof for further laterally converging the incident light beam reflected at the second reflective layer.