| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a coordinate input device easily detecting whether a pen is lifted up or put down. <P>SOLUTION: When a pointer interrupts a light beam emitted in substantially parallel to a coordinate input face, this optical coordinate input device detects the position of the pointer. The pointer has a light emission means starting light emission when the pen is put down. When the pen is lifted up, no light is emitted from the pointer, and a signal outputted from a CCD is generated by retroreflection light of the light beam. When the pen is put down, a signal, in which the light from the pointer is superimposed onto the retroreflection light, is detected. In this way, it is determined whether the pen is lifted up or put down when it is determined whether the light is superimposed or not in the signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
