| 摘要 |
A coordinate input apparatus detects the accurate position of the diffuse light emitted by the light emitting unit (5) of a pointer (4). The diffuse light emitted from the pointer is collected by a condenser lens (85), the amount of the diffuse light is detected by a control-signal detecting sensor (6) with a high sensitivity, its output is detected by a frequency detecting unit, and a control-signal detecting unit detects a control signal. The diffuse light emitted from the pointer also passes through a visible-light-cut filter (100) to remove disturbance light, and is received by linear sensors (20X,20Y) for detecting the direction in which the light comes. The linear sensors are controlled by a sensor control unit. The output signals of the linear sensors are converted by an A-D conversion unit (31A) provided for the sensor control unit, sent to a coordinate calculation unit, and the output coordinates on the sensors are calculated. |
