Patent ID: 7567077

Claim:
A non-contact position sensor comprising: a slider having a magnet having a front face along a longitudinal direction of the magnet that has one polarity and a back face along the longitudinal direction of the magnet that has an opposite polarity; a main stator consisting of a magnetic body having a first pair of opposed walls forming an area in which the slider enters while keeping a predetermined clearance, the first pair of opposed walls corresponding to the front and back faces of the magnet, and a first gap continuing into the opposed walls; a magnetically-sensitive sensor arranged in the first gap to detect a position of the slider corresponding to a percentage of the magnet entering the area; and an assist stator for preventing magnetic flux, which is generated in a part of the magnet that does not enter the area, from leaking out to the main stator, wherein the assist stator has a second pair of opposed walls corresponding to front and back faces of the part of the magnet that does not enter the area and transverse walls extending from the second pair of opposed walls which are separated from each other through a second gap formed between the transverse walls, wherein the first and second gaps are formed uniformly along a moving direction of the slider, respectively.