Patent ID: 6909686
Filing Date: 2005-06-21
Classification: G02B,G02F,G11B

Abstract:
1. An aberration correcting optical unit disposed in an optical path between a light source and an optical element for irradiating an information recording medium with a light beam emitted from said light source, in alignment with an optical axis, for correcting aberration of light caused by said information recording medium, comprising: a liquid crystal element exhibiting a predetermined alignment state by applying a predetermined voltage; and mutually opposing electrodes for applying voltages to said liquid crystal element, said mutually opposing electrodes sandwiching said liquid wystal element, wherein at least one of said mutually opposing electrodes has a plurality of electrode layers, said plurality of electrode layers being stacked in the direction of said optical axis and each of said plurality of electrode layers having at least one segment electrode, and the segment electrodes of said plurality of electrode layers are arranged so as to correct said aberration of light when voltages are applied to the segment electrodes.