| 摘要 |
<p>PURPOSE:To attain an optical scan at a high speed by selecting (n) pieces of elements which are not affected by the dispersion of light and actuating the paired light emitting elements and photoreceptors every (n) paired elements. CONSTITUTION:The infrared ray emitting element trains 3 and 5 and photoreceptor trains 2 and 4 are provided vertically and horizontally respectively at a display part 1. Then an input position indicated by a finger, etc. is detected with cut-off of light on a screen of the part 1. A sequence generating circuit 6 produces a sequence to drive X and Y light emitting elements in a fixed sequence. The control signal of this sequence is sent to a driving circuit 7 for light emitting element. The circuit 7 drives the designated X and Y light emitting elements. A reception data discriminating circuit 8 decides whether or not the light is cut off by a finger, etc. with the output of the photoreceptor in terms of X and Y directions. The drive of the element pairs for optical scan is carried out every (n) element pairs. This omits the malfunction preventing time due to the dispersion of light of the adjacent element pair and therefore attains an optical scan at a high speed. Thus a touched position can be detected in a short time with no malfunction.</p> |
