Patent ID: 7796490
Filing Date: 2010-09-14
Classification: G11B

Abstract:
1. A wavelength selectable deflecting element for deflecting light having wavelengths λ1, λ2, and λ3, said wavelengths λ1, λ2, and λ3 respectively corresponding to optical recording mediums having substrate thicknesses t1, t2, and t3, wherein t1<t2<t3 and λ1<λ2<λ3, said wavelength selectable deflecting element emitting a zero-order deflected light beam when light having the wavelength λ1 is incident, and said wavelength selectable deflecting element emitting a 1st-order deflected light beam when light having the wavelength λ2 or λ3 is incident, wherein said wavelength selectable deflecting element emits a 1st-order deflected light beam that is scattered to avoid overlapping a focused light spot when light having one of the wavelengths λ2 or λ3 is incident.