| 摘要 |
PROBLEM TO BE SOLVED: To cancel astigmatic difference provided in a laser light source and to form a laser beam having a rotary symmetric sectional shape without astigmatism. SOLUTION: The astigmatic difference adjusting device 1 is provided with a first parallel planar plate 2 arranged in the optical path of the laser beam and turnably supported around a first rotary axis Ax2 vertical to the central axis Ax1 of the laser beam and a second parallel planar plate 3 arranged in the optical path of the laser beam at a prescribed interval for the first parallel planar plate 2 and turnably supported around a second rotary axis Ax3 parallel to the first rotary axis Ax2. The first, second parallel planar plates 2, 3 are the same in thickness and refractive index, and when one side is turned by an interlocking means, the other side is constituted so as to be turned by the same angle in the opposite rotational direction. The first, second parallel planar plates 2, 3 are set integrally and turnably around the central axis Ax1 of the laser beam.
|
