| 摘要 |
PROBLEM TO BE SOLVED: To provide a focusing device capable of switching quickly a lens state of a liquid crystal lens. SOLUTION: The focusing device includes the liquid crystal lens for holding a liquid crystal layer by a pattern electrode group and a common electrode, and a controller for switching a voltage applied to the pattern electrode group to form a refractive index distribution in the liquid crystal layer. A voltage distribution 91 applied to each electrode when bringing the liquid crystal lens into a convex lens state is brought into a crossed state with a voltage distribution 92 applied to each electrode when bringing the liquid crystal lens into a concave lens state, the maximum voltage of the voltage distribution 91 is higher than the maximum voltage of the voltage distribution 92, and the minimum voltage of the voltage distribution 91 is lower than the minimum voltage of the voltage distribution 92. The liquid crystal lens is thereby switched quickly by reducing a change in the voltage applied to the liquid crystal layer, when switching the lens state, to shorten a transient response time of the liquid crystal layer. COPYRIGHT: (C)2009,JPO&INPIT |
