| 摘要 |
<p>The present invention selectively corrects astigmatism and is simple and inexpensive to implement. A spherical mirror (20), housed in an enclosure (18), is bent to simultaneously increase the radius of curvature in one plane and decrease the radius of curvature in the plane at right angles thereto. In one implementation the mirror is disposed in a mounting that includes a plurality of abutment surfaces against which a front surface of the spherical mirror abuts to effect bending of the mirror when it is appropriately disposed in the mounting. The plurality of abutment surfaces includes at least two bending surfaces and at least two support surfaces (62).</p> |
