| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a focal position variable space modulation device good in the image-formation performance. SOLUTION: The device is equipped with a refractive index variable material 30 disposed in the luminous flux, which deflects the incident light, a plurality of electrode pairs 11-16 and 21-26 disposed in the shape of a concentric circle, in the shape of concentric ellipse, or in the shape of a partial power concentric ellipse, whose both sides are faced almost mutually on both sides of the refractive index variable material 30, and the voltage impressing means which applies the voltage between electrode pair 11-16 and 21-26. The plurality of electrode pair 11-16, and 21-26 are disposed at the different spacings a, b, c, d and e in the device center and the circumscription part.</p> |
