| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a position detector capable of stably and surely executing the pen-down and pen-up of a position detector on the surface of a position detection area, reduced at its price and having durability. SOLUTION: The position detector is composed of the position indicator having a light reflection means for reflecting light, a light projection means for radiating light to the reflection means, a light receiving means for receiving light from the light reflection means of the position detector, and a coordinate calculation means for calculating the positional coordinates of the position detector, the position detector having a pen-like shape is provided with a movable pen core to be displaced by depression to the surface of a board, an optical modulation means for changing the characteristics of reflected light and a transmission means for transmitting the displacement of the pen core and the light receiving means has an up/down state detection means for obtaining the pen-up and pen-down information of the position detector by detecting the characteristic of light changed by the optical modulation means.</p> |
