Patent ID: 8049891

Claim:
An adjustment method for a position detection apparatus which comprises an optical system including a first optical member and a second optical member whose positions can be changed, and is configured to detect a position of a detection object, comprising the steps of: setting a plurality of different positions to position the first optical member in a direction perpendicular to an optical axis of the optical system; detecting light from the detection object via the optical system, while relatively moving the detection object in a direction of the optical axis of the optical system, for each of the plurality of positions set in the step of setting; calculating an evaluation value related to an asymmetry of a detection signal of the light, which is detected in the step of detecting, for each of the plurality of positions; specifying a position of the detection object in the direction of the optical axis of the optical system, at which the evaluation value calculated in the step of calculating is insensitive, for each of the plurality of positions; and adjusting a position of the second optical member, in a state where the detection object is positioned at the position specified in the step of specifying, by driving the second optical member in the direction perpendicular to the optical axis of the optical system so that a detection signal of the light from the detection object becomes symmetrical.