20130175428 | Optical Touch Panel Device for Construction Machine - An optical touch panel device for a construction machine capable of preventing the occurrence of a detection defect of a tactile contact point caused by external light falling upon a light-receiving element is provided with a planar panel with which tactile contact is made by an operator, light-emitting elements which emit light rays along the surface of the panel, and light-receiving elements which are provided to be paired with the light-emitting elements respectively so as to receive the light rays. The light-emitting elements are arranged so that the three light rays can intersect at each of a plurality of predetermined points upon a plane which is parallel to the panel, so that simultaneous interruption of at least two of the intersecting three light rays can be detected as tactile contact at a point of the surface of the panel facing the predetermined point. | 07-11-2013 |