| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a coordinate input device detecting the coordinate position of a light spot formed within a prescribed two-dimensional coordinate plane with high accuracy and high resolution by suppressing the influence of disturbance light. SOLUTION: When X and Y coordinate direction sensors 7 and 8 of ring CCD detect the spot position of light formed by a light emitting element 15 of a pointer 1, these sensors are functioned as an electronic shutter under the control of a control signal preparing circuit 21, this electronic shutter function is synchronized with the ON/OFF cycle of light emission from the pointer and when receiving the light of a low light receiving level, an electric charge corresponding to that received light is stored a lot of times on the circulation type transfer route of the relevant sensor and when receiving the light of a high light receiving level, the electric charge is stored a little times.</p> |
