Optical system, image display device, and imaging device

摘要

This optical system (100) comprises a prism (12) and a diffractive optical element (13). The prism (12) has a non-rotationally-symmetric aspheric surface for correcting eccentric aberration, and the diffractive optical element (13) includes a diffractive optical surface (DM) having a lattice structure that is as about an optical axis (Ax) of the optical system (100). The following condition is satisfied where ΔNe represents the refractive index difference of the diffractive optical surface (DM) in relation to the e-line (546.074 nm).
0.53>ΔNe>0.005  (1)

主权项

1. An optical system comprising an eccentric prism and a diffractive optical element; wherein
the eccentric prism has a non-rotationally-symmetric aspheric surface for correcting eccentric aberration; the diffractive optical element is of a multilayer type having a first diffraction grating and a second diffraction grating with intimate contact with each other, and a diffractive optical surface formed by the first diffraction grating and the second diffraction grating has a lattice structure that is asymmetric about an optical axis of the optical system; and the following condition (1) is satisfied where ΔNe represents the refractive index difference of the diffractive optical surface in relation to the e-line (546.074 nm),
0.53>ΔNe>0.005  (1) and further, the following condition (3) is satisfied, where: Φs represents the refractive power, in relation to the e-line, of a cross-section of the asymmetric lattice structure along which the paraxial power is the strongest; and Φm represents the refractive power, in relation to the e-line, of the asymmetric lattice structure along which the paraxial power is the weakest
5.0>Φs/Φm>1.02  (3).