| 摘要 |
<p>A coordinate detecting system comprising: a plurality of sensors (LS1, LS2: photosensor or the like) arranged in predetermined positions in areas for coordinate detection on an image display plane (4) for displaying an image with scanning lines; a counter (2a) for counting the number of input clock pulses in the horizontal direction of the image display plane and the number of scans in the vertical direction on the basis of the scanning timing of the scanning lines detected by the sensors; and a coordinate determining circuit (2a) for outputting the counted values, as relative coordinate values in the image display plane, at the instant when an external trigger signal (LP3) is inputted. The coordinates of an arbitrary position can be accurately obtained even when the display is of a special television type such as HDTV and no matter what the scanning method might be. It is also possible to detect the coordinate on a sub-frame.</p> |
