| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a coordinate input device, a control method therefor and a program that can calculate accurate coordinates independently of ambient environmental changes with use. <P>SOLUTION: Reference data representing a light quantity distribution acquired from a light reception part at a power input or system reset, which is not a coordinate input sampling state, under light projection by a light projection means is stored in a storage medium. Sampling data representing a light quantity distribution acquired from the light reception part in a coordinate input sampling state is acquired. Whether there is any change in ambient light on the coordinate input device is determined according to the acquired sampling data and the reference data stored in the storage medium. If any change in ambient light on the coordinate input device is detected, the reference data stored in the storage medium is updated or replaced with the sampling data. Coordinate values of a position pointed by a coordinate input are calculated from the sampling data and the reference data stored in the storage medium. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
