| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a variable optical attenuator with which density can be switched rapidly and a ranging apparatus using the variable optical attenuator. <P>SOLUTION: In the variable optical attenuator 200, a beam reflected on an optical member 205 of which the two reflection faces are vertically arranged is condensed on a flat mirror 220 via a condenser lens 202, and the beam reflected on the flat mirror 220 and substantially collimated with the condenser lens 202 is emitted via a density filter. The density of the density filter 204 varies in the direction perpendicular to the parallel motion of the beam, the flat mirror 220 is disposed tiltably with respect to the perpendicular direction, and the beam-transmitting position of the density filter 204 is changed by tilting the flat mirror 220. <P>COPYRIGHT: (C)2008,JPO&INPIT |
