| 摘要 |
An optical coordinate input device comprises a plurality of light emitting elements arranged so that their optical axes intersect mutually, a plurality of light receiving elements arranged so as to receive the light signals of the light emitting elements, a drive circuit for turning on/off the light emitting elements on the basis of a drive signal to cause them to provide the light signals, a first switching circuit for switching the output given from the drive circuit to among the light emitting elements, a second switching circuit for switching the signals given from the light receiving elements in correspondence with the light emitting element lighting, and a waveform shaping circuit for regulating the signal given from the second switching circuit to a certain voltage level on the basis of the drive signal. Since the waveform shaping circuit exerts its regulation action on the basis of the drive signal, the present optical coordinate input device can provide reliably the coordinate signal even if operated at a high speed without depending upon the precision of optical elements and without being influenced by disturbance light, switching noises, and the like.
|
