Abstract: Provided is a head-mounted display optical system (LS) having: an optical deflection element (M1); a first lens group (G1); a second lens group (G2); and an optical reflection element (M2). The head-mounted display optical system is configured such that light from a light source, which is reflected on a reflection surface (M2r) of the optical reflection element (M2) and reaches a drawing surface (I) assumed to be located on a retina when a user wears the head-mounted display, moves on the drawing surface (I) according to the change of a travelling direction of the light caused by the optical deflection element (M1), and an image is drawn on the drawing surface (I). The first lens group (G1) includes a free-shaped surface lens having a free-shaped surface which is rotationally asymmetrical with respect to a reference axis, and the reflection surface (M2r) of the optical reflection element (M2) is formed to be rotationally asymmetrical with respect to a reference axis.

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 ?Ne represents the refractive index difference of the diffractive optical surface (DM) in relation to the e-line (546.074 nm). 0.53>?Ne>0.

Abstract: A diffraction optical system comprises a free curve surface prism (14), and a multilayer diffractive optical element in which a plurality of diffractive element members (121, 122) are laminated together and a diffractive optical surface (DM) having a grating structure is formed at the interface thereof. The diffraction optical system further satisfies the following conditional expression: 0.005<(?Ng+?Ns)/2<0.45, where ?Ng denotes a refractive index difference at g-line on the diffractive optical surface (DM), and ?Ns denotes a refractive index difference at s-line on the diffractive optical surface (DM).

Abstract: Provided is a zoom lens having, in order from an object: a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; and a third lens group (G3) having positive refractive power. The first lens group (G1) and the third lens group (G3) respectively move toward the object upon zooming from the wide-angle end state to the telephoto end state. The first lens group (G1) includes a diffraction optical element (DOE) in which two optical elements, constituted by optical materials of which refractive index difference at the d-line is 0.45 or less, are cemented and a diffraction optical surface (corresponding to the optical surface with the radius of curvature R8 in FIG. 1) on which diffraction grating grooves are formed, exists on the interface of the two optical elements. The zoom lens satisfies the following conditional expressions: 0.05<?1/ft<1.00, and 3.0<?d/y<10.

Abstract: Provided is a head-mounted display optical system (LS) having: an optical deflection element (M1); a first lens group (G1); a second lens group (G2); and an optical reflection element (M2). The head-mounted display optical system is configured such that light from a light source, which is reflected on a reflection surface (M2r) of the optical reflection element (M2) and reaches a drawing surface (I) assumed to be located on a retina when a user wears the head-mounted display, moves on the drawing surface (I) according to the Change of a travelling direction of the light caused by the optical deflection element (M1), and an image is drawn on the drawing surface (I). The first lens group (G1) includes a free-shaped surface lens having a free-shaped surface which is rotationally asymmetrical with respect to a reference axis, and the reflection surface (M2r) of the optical reflection element (M2) is formed to be rotationally asymmetrical with respect to a reference axis.

Abstract: Provided is a zoom lens having, in order from an object: a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; and a third lens group (G3) having positive refractive power. The first lens group (G1) and the third lens group (G3) respectively move toward the object upon zooming from the wide-angle end state to the telephoto end state. The first lens group (G1) includes a diffraction optical element (DOE) in which two optical elements, constituted by optical materials of which refractive index difference at the d-line is 0.45 or less, are cemented and a diffraction optical surface (corresponding to the optical surface with the radius of curvature R8 in FIG. 1) on which diffraction grating grooves are formed, exists on the interface of the two optical elements. The zoom lens satisfies the following conditional expressions: 0.05<?1/ft<1.00, and 3.0<?d/y<10.

Abstract: A diffraction optical system comprises a free curve surface prism (14), and a multilayer diffractive optical element in which a plurality of diffractive element members (121, 122) are laminated together and a diffractive optical surface (DM) having a grating structure is formed at the interface thereof. The diffraction optical system further satisfies the following conditional expression: 0.005<(?Ng+?Ns)/2<0.45, where ?Ng denotes a refractive index difference at g-line on the diffractive optical surface (DM), and ?Ns denotes a refractive index difference at s-line on the diffractive optical surface (DM).

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 azo having a lattice structure that is as about an optical axis (Ax) of the optical system (100). The following condition is satisfied where ?Ne represents the refractive index difference of the diffractive optical surface (DM) in relation to the e-line (546.074 nm). 0.53>?Ne>0.

Abstract: A small shooting lens has high optical performance and is suitable for mass production. To attain this, the shooting lens includes at least three lens groups disposed in order from an object side, wherein an adhesion multiple-layer diffractive optical element is formed on one of surfaces disposed between an object surface and an imaging plane, and a maximum image height Y and an entire length L satisfy 0.1<Y/L<3.0 . . . (1). Thus using the multiple-layer diffractive optical element in the shooting lens makes it possible to improve diffraction efficiency over a wide range and reduce flare. Particularly, the multiple-layer diffractive optical element has a merit that its production and assembling are easy. Further, according to the conditional expression (1), it is possible to realize the downsizing of the shooting lens while also maintaining its imaging quality.

Abstract: An eye piece (EL1) is formed having a first lens (L1) having a positive refractive power and a second lens (L2) having a positive refractive power, which are disposed in order from an object (O), and a contact multi-layer diffractive optical element (DOE), which has a first optical element (51) formed with a relief pattern and a second optical element (52) which is in contact with the surface of the first optical element (51) where the relief pattern is formed, is disposed on an optical surface of the first lens (L1) or the second lens (L2).

Abstract: A diffractive optical system including a diffractive optical element is provided with a first lens component having a first positive lens, and a second lens component having a second positive lens and a negative lens. The diffractive optical element has a first diffractive optical member having a first diffractive optical surface, and a second diffractive optical member having a second diffractive optical surface. The first diffractive optical member and the second diffractive optical member are arranged so that the first diffractive optical surface and the second diffractive optical surface are in contact with each other. A refractive index of the first diffractive optical member and a refractive index of the second diffractive optical member at the d line are different from each other.

Abstract: A diffractive optical system including a diffractive optical element has a concave lens component having a first diffractive optical surface, and an optical member having a second diffractive optical surface, the concave lens component and the optical member being arranged so that the first diffractive optical surface and the second diffractive optical surface face each other, and the conditional expression 0.003<t/f<0.3 being satisfied, where t is the thickness of the concave lens component on the optical axis, and f is the focal length of the diffractive optical system.

Abstract: A spectacle lens includes a multi-contact diffractive optical element formed on at least one surface of a overall lens system that is arranged from an object to a pupil, in which an apparent Abbe number Vd when the overall lens system including the multi-contact diffractive optical element is regarded as a single lens satisfies Vd>60 . . . (1).

Abstract: A diffractive optical element 10 is constituted by sandwiching and closely bonding first and second optical element components 13, 14 which have different refractive indices and are adhered via a relief pattern 20, between third and fourth optical element components 11, 12.

Abstract: A diffractive optical system including a diffractive optical element has a concave lens component having a first diffractive optical surface, and an optical member having a second diffractive optical surface, the concave lens component and the optical member being arranged so that the first diffractive optical surface and the second diffractive optical surface face each other, and the conditional expression 0.003<t/f<0.3 being satisfied, where t is the thickness of the concave lens component on the optical axis, and f is the focal length of the diffractive optical system.

Abstract: A diffractive optical system including a diffractive optical element is provided with a first lens component having a first positive lens, and a second lens component having a second positive lens and a negative lens. The diffractive optical element has a first diffractive optical member having a first diffractive optical surface, and a second diffractive optical member having a second diffractive optical surface. The first diffractive optical member and the second diffractive optical member are arranged so that the first diffractive optical surface and the second diffractive optical surface are in contact with each other. A refractive index of the first diffractive optical member and a refractive index of the second diffractive optical member at the d line are different from each other.

Abstract: A spectacle lens includes a multi-contact diffractive optical element formed on at least one surface of a overall lens system that is arranged from an object to a pupil, in which an apparent Abbe number Vd when the overall lens system including the multi-contact diffractive optical element is regarded as a single lens satisfies Vd>60 . . . (1).

Abstract: A small shooting lens has high optical performance and is suitable for mass production. To attain this, the shooting lens includes at least three lens groups disposed in order from an object side, wherein an adhesion multiple-layer diffractive optical element is formed on one of surfaces disposed between an object surface and an imaging plane, and a maximum image height Y and an entire length L satisfy 0.1<Y/L<3.0 . . . (1). Thus using the multiple-layer diffractive optical element in the shooting lens makes it possible to improve diffraction efficiency over a wide range and reduce flare. Particularly, the multiple-layer diffractive optical element has a merit that its production and assembling are easy. Further, according to the conditional expression (1), it is possible to realize the downsizing of the shooting lens while also maintaining its imaging quality.

Abstract: An eye piece (EL1) is formed having a first lens (L1) having a positive refractive power and a second lens (L2) having a positive refractive power, which are disposed in order from an object (O), and a contact multi-layer diffractive optical element (DOE), which has a first optical element (51) formed with a relief pattern and a second optical element (52) which is in contact with the surface of the first optical element (51) where the relief pattern is formed, is disposed on an optical surface of the first lens (L1) or the second lens (L2).

Abstract: The present invention is a diffractive optical element 1 in which mutually different materials make contact with one another via the same diffraction grating groove 30. One of the mutually different materials is a first ultraviolet curing resin 10 and the other of the mutually different materials is a second ultraviolet curing resin 20 that is different from the first ultraviolet curing resin 10.