Measuring apparatus and measuring method for measuring axis tilt of shaft of motor for polygon mirror

摘要

A measuring apparatus includes a light source emitting a measuring light, a first photo-detection element directly receiving a part of a reflected light of the measuring light reflected from a shaft to be measured to detect a first light receiving position, and a second photo-detection element directly receiving another part of the reflected light to detect a second light receiving position. An axis tilt angle of the shaft is measured on the basis of a signal output from the first photo-detection element and a signal output from the second photo-detection element.