Patent ID: 7859952
Filing Date: 2010-12-28
Classification: G04C

Abstract:
1. A hand position detecting device comprising: a seconds wheel having an aperture provided at a predetermined position therein; a center wheel disposed on the same axis as the seconds wheel and having a circular aperture provided at a predetermined position thereon; an hour wheel disposed on the same axis as the seconds and center wheels and having eleven circular apertures provided thereon at angular intervals of degrees starting at a predetermined position provided thereon along the periphery thereof; an intermediate wheel having an aperture which can align with the aperture in the center wheel; aperture detecting means including a light emission element and a photodetection element provided in a spaced relationship at a predetermined detection position for detecting whether light emitted by the light emission element has passed through the apertures in the seconds, center, hour and intermediate wheels, thereby determining the respective rotational positions of the seconds, center and hour wheels; and center hand position detecting means for rotating the center wheel one step at a time in a predetermined direction to a position where the aperture in the center wheel aligns with the aperture in the intermediate wheel, thereby causing the aperture detecting means to detect light passing through the aligning apertures in the center and intermediate wheels, for returning the center wheel a predetermined number of steps or more, for further rotating the center wheel one step at a time in the predetermined direction to the position where the aperture detecting means detected the light, thereby causing the aperture detecting means to try to detect light again at the position, and for determining, when the aperture detecting means detects light again, the position of the aperture in the center wheel through which the aperture detecting means detected the light last, as the predetermined position in the center wheel.