Patent ID: 8564756
Filing Date: 2013-10-22
Classification: G02F

Abstract:
1. An optical system comprising: at least one lens; a liquid crystal optical element comprising a first diffractive liquid crystal lens and a second diffractive liquid crystal lens that are arranged to oppose each other with orientation directions thereof being perpendicular to each other in a plane perpendicular to an optical axis and a control portion that adjusts a voltage applied to the liquid crystal optical element for compensating for a shift of a focal position relative to incident light from a different object point; wherein the optical system is configured so that a far object point is in focus in a state where the liquid crystal optical element is made to fail to have a ray deflecting action by the control portion and so that a near object point is in focus in a state where the liquid crystal optical element is made to have the ray deflecting action by the control portion, and wherein the optical system satisfies the following condition: where y is a height of a most off-axis chief ray in the liquid crystal optical element and sd is an effective radius of the liquid crystal optical element.