| 摘要 |
PROBLEM TO BE SOLVED: To easily control the flux diameter of a light beam and to simplify the constitution by deforming the part of a reflecting surface according to the application state of an electric field to separate and cut off part of the light beam. SOLUTION: When a selection switch SW is turned on, an electric field is produced between a 1st electrode pattern 82 and a 2nd electrode pattern 84 with the voltage from a voltage source Vdd. With this electric field, the annular inside part of the 2nd electrode pattern 84 which faces a common part 92 curves arcuately downward with the 1st reflecting substance layer pattern 94. Consequently, the marginal part of a light beam which is made incident at 45 deg. is reflected at an angle larger or smaller than 45 deg. and the remaining center part is reflected at 45 deg.. Consequently, the marginal part of the light beam traveling to a target is separated and cut off by the 1st reflecting substance layer pattern 94. |
