Touch operation signal output device

摘要

A method and apparatus are provided for reliably detecting a touch operation in a touch sensitive control surface (3), despite the influence of light or the existence of an obstruction. In the touch tracer, LEDs (19) and phototransistors (20) for detecting a touch position on the input pad (3) are arranged to form parallel optical axes in the vertical direction and the horizontal direction. The optical axes of the LEDs (19) and the phototransistors (20) are alternately arranged in opposite directions to the adjacent optical axis. Moreover, the front surface of the phototransistor (20) is closed except for an aperture (27) that forms an optical axis only between opposing LEDs (19) and phototransistors (20). The apertures (27) are divided in half into top and bottom portions by a light-shielding film (24). Because of the light-shielding film (24), the phototransistor (20) does not receive any light interference from the adjacent LED (19) or incidental sunlight. <IMAGE>