Method for detecting origin point of position sensor

Abstract

A method for detecting the point of origin of a position sensor such as an optical linear scale by first displacing an object member whose position is to be determined until it butts against a mechanical stopper, then determining the position of the object member at the mechanical stopper and using that position as a reference position for the point of origin, and thereafter detecting the position of the object member by means of the position sensor, thereby detecting the position of the object member relative to the point of origin. In another embodiment, a first point of origin signal is obtained from an optical linear scale used as a position sensor and stored in response to latching signal generated at an end point of travel of the object member. Subsequently, when a second point of origin signal from the optical linear scale is compared with the first point of origin signal, any deviation from the first point of origin signal may be corrected based on the result of the comparison.

Dependencies are inferred from the claim text.