| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical system coordinate input device which can discriminate a position indicator and a finger without being affected by external light. SOLUTION: The optical system coordinate input device having a coordinate detection area is provided with a first position indicating body having a light radiating means, a light receiving means constituted of a lens system for detecting the incident angle of incident light and an array of a plurality of light receiving elements, a coordinate calculating means calculating the coordinate position of the first position indicating body by the principle of triangulation based on the detected incident angle, a discrimination means discriminating light radiated from the light radiating means and external light entering from outside and a polarization means having a first polarized surface and a second polarized surface, whose polarized axes for shielding external light differ. Light radiated from the light radiating means passes through only the first polarized surface or the second polarized surface and external light passes through the first polarized surface or the second polarized surface and is made incident on the other surface. Then, external light is shielded.</p> |
