| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a large screen and high resolution and to precisely input coordinates by allowing multiple photodetecting means to have their photodetection area overlapping with one another. SOLUTION: The output signals of four linear sensors 20Xa, 20Xb, 20Yc, and 20Yd are converted by an AD conversion part 31A provided on a sensor control part 31 into digital signals, which are sent to a coordinate arithmetic part 32 to calculate coordinate values. The linear sensors 20Xa and 20Xb are constituted as detection areas which are longitudinally halves of the screen and the detection areas overlap with each other nearby the center. The linear CCDs of the sensors 20Xa and 20Xb are both measurable areas and reference points are predefined. Namely, input to the overlap part on the screen is done and read in as coordinates. Those values are stored as reference point data in a nonvolatile memory and those values are read out in normal use to calculate coordinate values. Consequently, the linear CCDs can be handled as if they are one linear CCD.</p> |
