Coordinate input apparatus

摘要

A coordinate input apparatus includes a light projecting unit configured to project light parallelly to an effective coordinate input region, a reflection unit configured to retroreflect the light projected by the light projecting unit, and a light receiving unit configured to receive light from the light projecting unit or the reflection unit. The coordinate input apparatus includes a moving unit configured to move a set of the light projecting unit, light receiving unit, and reflection unit in a direction perpendicular to the effective coordinate input region in order to ensure a light amount with which a pointed position in the effective coordinate input region can be calculated based on variations of a light amount distribution obtained from the light receiving unit.

主权项

1. A coordinate input apparatus which detects a pointed position to an effective coordinate input region, comprising:
a light projecting unit constructed to project light to the effective coordinate input region; a reflection unit constructed to retroreflect the light projected by said light projecting unit; a light receiving unit constructed to receive light from one of said light projecting unit and said reflection unit; a moving unit constructed to move a set of said light projecting unit, said light receiving unit, and said reflection unit in order to change a light amount received by said light receiving unit; a determination unit constructed to determine whether the light amount received by said light receiving unit is appropriate for calculating the pointed position in the effective coordinate input region; and a notification unit constructed to notify a determination result of said determination unit.