Abstract: An image projection apparatus includes light sources 111 to 113 emitting at least two colored lights whose wavelengths are different from each other, a polarization conversion element 2 controlling a polarization direction of the colored light, at least two light modulation elements 41 and 42 modulating incident light, a light guide optical system 31 guiding the at least two colored lights from the polarization conversion element to the at least two light modulation elements in accordance with the polarization direction, and a projection optical system 5. One of the at least two colored light and the other are emitted as lights whose polarization directions are different from each other from the polarization conversion element. A drive unit 6 turns on the light sources so that the one of the colored lights and at least one of the other enter the at least two light modulation elements at the same time.

Abstract: A color separation/combination prism is disclosed which has an optical film arrangement capable of performing color separation, light analysis and color combination. The prism includes four prism members and at least five optical surfaces as outer surfaces thereof. Each of the prism members has at least three optical surfaces including two optical surfaces which intersect orthogonally with each other at a first side thereof. The four prism members are joined together such that the first sides of the prism members are adjacent to or contact each other. Joining portions of the four prism members are provided with wavelength-selective polarizing films.

Abstract: An optical system includes an optical element formed of resin. On at least one of optical surfaces on the light incidence side of the optical element formed of resin, a plurality of depressions or protrusions of a size not larger than the wavelengths of visible light is formed without a periodic structure or in a random arrangement.

Abstract: A color separation/combination prism is disclosed which has an optical film arrangement capable of performing color separation, light analysis and color combination. The prism includes four prism members and at least five optical surfaces as outer surfaces thereof. Each of the prism members has at least three optical surfaces including two optical surfaces which intersect orthogonally with each other at a first side thereof. The four prism members are joined together such that the first sides of the prism members are adjacent to or contact each other. Joining portions of the four prism members are provided with wavelength-selective polarizing films.

Abstract: A polarizing beam splitter includes a polarization splitting layer which includes stacked one-dimensional grating layers. The grating layers can include alternating layers of at least one H layer having an effective refractive index nH for p-polarized light and at least one L layer having an effective refractive index nL for p-polarized light.

Abstract: The polarization beam splitter of the present invention includes a polarized beam splitting layer having a structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, light having a chiefly polarized component parallel to the first direction is transmitted therethrough, and light having a chiefly polarized component parallel to the second direction is reflected.

Abstract: A color separation/combination prism is disclosed which has an optical film arrangement capable of performing color separation, light analysis and color combination. The prism includes four prism members and at least five optical surfaces as outer surfaces thereof. Each of the prism members has at least three optical surfaces including two optical surfaces which intersect orthogonally with each other at a first side thereof. The four prism members are joined together such that the first sides of the prism members are adjacent to or contact each other. Joining portions of the four prism members are provided with wavelength-selective polarizing films.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure.

Abstract: In the conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. In a conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure. The first periodic structure and the second periodic structure transmit light having first polarization direction and reflect light having second polarization direction orthogonal to the first direction.

Abstract: In a conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure.

Abstract: A polarizing beam splitter includes a polarization splitting layer which includes stacked one-dimensional grating layers. The grating layers can include alternating layers of at least one H layer having an effective refractive index nH for p-polarized light and at least one L layer having an effective refractive index nL for p-polarized light.

Abstract: A high performance polarization splitting element and an optical device using the polarization splitting element are provided. According to an embodiment of the present invention, the optical device includes a first periodic structure having a period shorter than a wavelength of used light, a second periodic structure which has a period shorter than the wavelength of the used light and in which a direction of the period is orthogonal to or substantially orthogonal to that of the first periodic structure, and a pair of optical elements disposed so as to sandwich the first periodic structure and the second periodic structure. The second periodic structure is adjacent to the first periodic structure.

Abstract: An observation optical system including an objective optical part which forms an image of an object, an image inverting part which converts an image formed by said objective optical part into an erect image, and an eyepiece optical part which guides the erect image converted by said image inverting part to an observer. The objective optical part has a first lens unit with a negative power and a second lens unit with a positive power arranged from an object side in the order named, and said second lens unit is movable in a direction including a component perpendicular to an optical axis to stabilize an image.

Abstract: In the conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.

Abstract: A zoom lens is disclosed comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power, a fourth lens unit of negative refractive power, a fifth lens unit of positive refractive power and a sixth lens unit of negative refractive power, wherein, during zooming from the wide-angle end to the telephoto end, the air separations between the i-th and (i+1)st lens units are made to vary properly and the ratio of the focal length of the fourth lens unit to the longest focal length of the entire system is made to have a proper value. In particular, a zoom lens is disclosed wherein the second lens unit is made to decenter to stabilize the image.

Abstract: A zoom lens is disclosed comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power, a fourth lens unit of negative refractive power, a fifth lens unit of positive refractive power and a sixth lens unit of negative refractive power, wherein, during zooming from the wide-angle end to the telephoto end, the air separations between the i-th and (i+1)st lens units are made to vary properly and the ratio of the focal length of the fourth lens unit to the longest focal length of the entire system is made to have a proper value. In particular, a zoom lens is disclosed wherein the second lens unit is made to decenter to stabilize the image.

Abstract: An observation optical system including an objective optical part which forms an image of an object, an image inverting part which converts an image formed by said objective optical part into an erect image, and an eyepiece optical part which guides the erect image converted by said image inverting part to an observer. The objective optical part has a first lens unit with a negative power and a second lens unit with a positive power arranged from an object side in the order named, and said second lens unit is movable in a direction including a component perpendicular to an optical axis to stabilize an image.

Abstract: A zoom lens is disclosed comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power, a fourth lens unit of negative refractive power, a fifth lens unit of positive refractive power and a sixth lens unit of negative refractive power, wherein, during zooming from the wide-angle end to the telephoto end, the air separations between the i-th and (i+1)st lens units are made to vary properly and the ratio of the focal length of the fourth lens unit to the longest focal length of the entire system is made to have a proper value. In particular, a zoom lens is disclosed wherein the second lens unit is made to decenter to stabilize the image.