| 摘要 |
PROBLEM TO BE SOLVED: To provide a coordinate input device capable of using an existing white board or a wall surface of a conference room as a projection surface, and controlling a display screen by touching the projection surface.SOLUTION: A coordinate input device includes: a light-projection unit that projects light directed in parallel with a coordinate input effective area; a reflection unit that recursively reflects the light projected by the light-projection unit; and a light-receiving unit that receives the light from the light-projection unit or the reflection unit. The coordinate input device further includes a moving unit that moves the light-projection unit, the light-receiving unit, and the reflection unit as a set in a vertical direction relative to the coordinate input effective area, so as to ensure the quantity of light that allows calculation of an indication position of the coordinate input effective area on the basis of a variation in light quantity distribution obtained from the light-receiving unit. |
