摘要 |
<p>In an apex-angle variable prism comprising a combination of a planoconcave lens (3) and a planoconvex lens (4), at least one lens is simply and stably rotated along the spherical surfaces of these lens by using a compact actuator. In order to rotate the planoconvex lens along the spherical surface of the planoconcave lens, the one end of the planoconvex lens is supported by a pivot bearing (33) disposed on the rotational center line X2 which passes through the center O2 of the radius of curvature of the sphere of the planoconvex lens, and the other end of the planoconvex lens is rotated along the rotational reference plane Z perpendicular to the rotational center line X2 by using a compact DC motor (42).</p> |