| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the usability by making it possible to use a light reflection type indicator which is smaller and lighter than a light pen in a coordinate input system which provides a coordinate input function on a transmission type screen for image display of a back projection type display device, etc. SOLUTION: This system has an infrared light source 3 projecting infrared light on the back of the transmission type screen 2 for image display, a CCD camera 4 having its photography range on the back of the transmission type screen, and an image pickup information processing circuit 5 which generates coordinate information on the light reflection indicator 1 positioned on the front of the transmission type screen 2 from the image pickup information outputted by the CCD camera 4. This coordinate input system eliminates the need to incorporate a battery and electronic components into the position indicator and then becomes easy to use.</p> |
