Optical system, image display device, and imaging device
First Claim
Patent Images
1. An optical system comprising an eccentric prism and a diffractive optical element;
- whereinthe 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 Δ
Ne represents the refractive index difference of the diffractive optical surface in relation to the e-line (546.074 nm),
0.53>
Δ
Ne>
0.005
(1)and further, the following condition (3) is satisfied, where;
Φ
s 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
Φ
m 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>
Φ
s/Φ
m>
1.02
(3).
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Abstract
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)
20 Citations
19 Claims
-
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 Δ
Ne represents the refractive index difference of the diffractive optical surface in relation to the e-line (546.074 nm),
0.53>
Δ
Ne>
0.005
(1)and further, the following condition (3) is satisfied, where;
Φ
s 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
Φ
m 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>
Φ
s/Φ
m>
1.02
(3). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- wherein
-
14. An optical system comprising an eccentric prism consisting of only a single piece of material and a diffractive optical element;
- wherein
the eccentric prism has a first surface through which light enters into the eccentric prism, a second surface by which the light entered into the eccentric prism is internally reflected, and a third surface through which the internally reflected light is emitted, at least one of the first, the second and the third surfaces is a non-rotationally-symmetric aspheric surface for correcting eccentric aberration; the diffractive optical element is inside the eccentric prism and 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 Δ
Ne represents the refractive index difference of the diffractive optical surface in relation to the e-line (546.074 nm),
0.53>
Δ
Ne>
0.005
(1). - View Dependent Claims (15, 16, 17, 18, 19)
- wherein
Specification