SCALE FOR ADJUSTING ROTATION DIRECTION OF OPTICAL ELEMENT AND ADJUSTING METHOD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a scale for adjusting rotation direction to highly precisely and easily detect the rotation angle of the beam spot row of a plurality of beams emitted by optical element, when adjusting the rotation angle of an optical element with respect to a reference part or a reference line of an optical device, in the assembly into the optical device of the optical element emitting a plurality of beams, and an adjusting method of rotation direction using the same. SOLUTION: By using the scale 1 having an optical pattern 2 that is made right-angled to the moving direction of an optical element 4 emitting a plurality of beams and that is worked with fixed intervals L in the moving direction, the phase difference of the periodic electric signals between each beam is detected with periodic electric signals from the photodetector of the optical element 4 corresponding to each of a plurality of beams obtained by moving the optical element 4 perpendicularly to the optical pattern 2 of the scale 1, and the rotation angle of the beam spot row of a plurality of beams emitted by the optical element is calculated and detected on the basis of the phase difference.