| 摘要 |
PROBLEM TO BE SOLVED: To provide a focusing device, quickly switching a liquid crystal lens between a state without a lens effect and a state having a lens effect. SOLUTION: This focusing device includes a liquid crystal lens holding a liquid crystal layer between a pattern electrode group and a common electrode, and a controller for switching voltage applied to the pattern electrode group to form a refractive index distribution in the liquid crystal layer. The focusing device forms a voltage distribution 92 of the same voltage in the pattern electrode group so that the liquid crystal lens is put in the state without a lens effect. Further, in order to put the liquid crystal lens in a convex lens state, a voltage distribution 91 including lower voltage and higher voltage than the voltage forming the voltage distribution 92 is formed in the pattern electrode group. Thus, a change in voltage applied to the liquid crystal layer in switching the liquid crystal lens between the state without a lens effect and the convex lens state is decreased to shorten transient response time of the liquid crystal layer, thereby quickly performing switching of the liquid crystal lens. COPYRIGHT: (C)2009,JPO&INPIT |
