| 摘要 |
<p>PURPOSE:To miniaturize and integrate photodetectors without changing coordinate resolution to simplify the constitution of the title device by detecting the formed image of a cross-like beam on a display screen formed through a condenser lens by means of the photodetectors. CONSTITUTION:A projector 1 is used for projecting a cross-like beam to the display screen of a large display 2, the condenser lens 3 is used for contracting the large display 3 to form an image and plural photodetectors are arranged on the image forming position of the display 2. Beams A projected from the projector 1 to the display are turned to A'-D' by the elements 4, a photodetecting circuit control device 5 outputs a coordinate signal S3 for A'-D' and a coordinate arithmetic unit 6 calculates the coordinates of an intersecting point P'. A display control device 7 executes display screen control such as the switching of the display screen, expansion, and the display of a similar screen. Consequently, the photodetectors can be miniaturized and integrated and a coordinate input device with a simple constitution can be attained.</p> |
