Patent ID: 8759743

Claim:
An input device, comprising: a retainer plate in the form of a frame; an optical waveguide in the form of a frame, the optical waveguide being provided on a front surface of the retainer plate such that the frame of the optical waveguide is aligned with the frame of the retainer plate, the optical waveguide having first and second sections opposed to each other in the form of the frame, the first section including light-emitting cores disposed in a predetermined pattern, the second section including light-receiving cores disposed in a predetermined pattern, the light-emitting cores and the light-receiving cores having respective front end surfaces positioned on inner edges of the frame, the front end surfaces of the light-emitting cores and the front end surfaces of the light-receiving cores being opposed to each other, the optical waveguide further including an over cladding layer having an edge portion covering the front end surfaces of the light-emitting and light-receiving cores, the edge portion of the over cladding layer being in the form of a lens portion; a light-emitting element connected to rear ends of the light-emitting cores of the optical waveguide; and a light-receiving element connected to rear ends of the light-receiving cores of the optical waveguide, the light-receiving element including a light-receiving section disposed in an upper part thereof, the light-receiving element having a lower end portion positioned closer to the retainer plate, wherein the optical waveguide has a light-receiving optical waveguide section in which the light-receiving cores are formed, the light-receiving optical waveguide section and the light-receiving element being placed upside down so that the light-receiving section is positioned in a lower part of the light-receiving element and so that the lower end portion of the light-receiving element is positioned above the light-receiving optical waveguide section, whereby light beams emitted from the light-emitting element, passing through the light-emitting cores, exiting the lens portion of the over cladding layer covering the front end surfaces of the light-emitting cores, and traveling within the frame of the optical waveguide are designed so that the vertical position of the light beams is low with respect to the back surface of the retainer plate.