Abstract: A projection lens of the following structure was invented for the purpose of providing a bright projection optical system with the F-number of approximately 2 or lower while maintaining good optical characteristics, in an image display apparatus. The projection lens is constructed of six lens units, a first lens unit L1 of a negative optical power, a second lens unit L2 of a positive optical power, a third lens unit L3 of a positive optical power, a fourth lens unit L4 of a negative optical power, a fifth lens unit L5, and a sixth lens unit L6 of a positive optical power, in the order named from the enlargement conjugate side, and four lens units (L2 to L5) out of the lens units move toward the enlargement conjugate side during zooming from the wideangle extreme to the telephoto extreme.

Abstract: An eyepiece lens is constructed with, in order from an entrance side for light to an exit side for light, first, second, third, fourth and fifth lens units of negative, positive, positive, positive and positive refractive powers, respectively. Each of the first, second, third, fourth and fifth lens units of the eyepiece lens is composed only of one lens or a cemented lens, and an intermediate image by an objective lens is formed between the second lens unit and the third lens unit. An objective lens is constructed with, in order from an object side to an image side, first and second lens units of positive and negative refractive powers, respectively. The first and second lens units of the objective lens are composed of one positive lens and of one positive lens and one negative lens, respectively, and the various conditions are appropriately set. An optical apparatus includes the eyepiece lens, the objective lens and an erecting prism.

Abstract: A projection-type image displaying device includes liquid crystal elements for modulating light rays having wavelength regions different from each other, a color combining optical element for combining the light rays modulated by the liquid crystal display elements, and a projection type optical system for projecting light rays combined by the color combining optical element to display an image. Polarizing elements are disposed on an incidence side and an exit side of the liquid crystal display elements. Optically anisotropic elements for correcting the optical anisotropy of each of the liquid crystal elements are disposed between the polarizing elements. An air-reduced distance Linp between an entrance pupil of the projection optical system and display surfaces of the liquid crystal display element and diagonal length Ldisp across corners of the display surface of the liquid crystal display elements meet the predetermined condition.

Abstract: The present invention has as its object to provide a projection type display apparatus which suffers little from the occurrence of the distortion of the surface of a dichroic mirror in a color combining optical system, and the occurrence of the deformation of a projected image by the angular deviation of the surface of the dichroic mirror and in which the correction of the chromatic aberration of magnification of a projection lens is stably possible during mass production. So, the color combining system of the present invention is provided with at least three prisms, two dichroic mirror layers for reflecting lights differing in wavelength area from each other, the two dichroic mirror layers being formed so as not to intersect with each other with one of the three prisms which is located most adjacent to the light exit side interposed therebetween, and at least one optical element having positive or negative refractive power.

Abstract: An observation optical system includes, in order from an object side, an objective lens having a first lens unit of positive refractive power, a second lens unit of negative refractive power and a third lens unit of positive refractive power, an erect optical system, and an eyepiece lens of positive refractive power for observing an object image formed through the objective lens, wherein an air separation between the first lens unit and the second lens unit and an air separation between the second lens unit and the third lens unit are made variable to effect variation of magnification.

Abstract: For providing the image projecting system capable of substantially superimposing images without image blur which are provided from a plurality of image projecting apparatus when the original images are superimposed using the plurality of image projecting apparatus, distortion value of distortion aberration of images from projecting optical system comprised in the image projecting system is made substantially coincided in a region of using image height.

Abstract: A lighting device is disclosed which comprises an illuminating light source for illuminating an object, a first optical unit disposed on the side of the object of the illuminating light source and having an optical action section for diverging light or an optical action section for converging light, and a second optical unit disposed on the side of the object of the optical action section of the first optical unit and having an optical action section for exhibiting a characteristic opposite to a characteristic of the optical action section, wherein the optical action section of the second optical unit overlies the optical action section of the first optical unit in varying areas to change light distribution characteristic on the side of the object.

Abstract: An eyepiece lens is constructed with, in order from an entrance side for light to an exit side for light, first, second, third, fourth and fifth lens units of negative, positive, positive, positive and positive refractive powers, respectively. Each of the first, second, third, fourth and fifth lens units of the eyepiece lens is composed only of one lens or a cemented lens, and an intermediate image by an objective lens is formed between the second lens unit and the third lens unit. An objective lens is constructed with, in order from an object side to an image side, first and second lens units of positive and negative refractive powers, respectively. The first and second lens units of the objective lens are composed of one positive lens and of one positive lens and one negative lens, respectively, and the various conditions are appropriately set. An optical apparatus includes the eyepiece lens, the objective lens and an erecting prism.

Abstract: For increasing the illumination efficiency to a liquid-crystal display element, an illuminating apparatus has a reflector for reflecting light from a light source, a negative meniscus lens, which is convex on the light source side, a first lens array unit of lens elements, a second lens array unit of lens elements, which is conjugate with the light source, and an optical polarization converting element in the stated order along a traveling direction of the light from the light source. The illuminating apparatus illuminates the liquid-crystal display element through the optical polarization converting element.

Abstract: A projection-type image displaying device includes liquid crystal display elements 13, 20 and 30 for modulating light rays having wavelength regions different from each other, a color combining optical element CSP1 for combining the light rays modulated by the liquid crystal display elements, and a projection optical system 36 for projecting light ray combined by the color combining optical element to display an image. Polarizing elements 11 and 15 are disposed on an incidence side and an exit side of the liquid crystal display element. Optically anisotropic element 12 and 14 for correcting the optical anisotropy of the liquid crystal element is disposed between the polarizing elements. An air-reduced distance Linp between an entrance pupil of the projection optical system and display surfaces of the liquid crystal display element and diagonal length Ldisp across corners of the display surface of the liquid crystal display elements meet the predetermined condition.

Abstract: This specification discloses an illuminating device in which lights emitted from a plurality of light sources are made into substantially parallel lights and are made to enter a lens array system, and illumination is effected by the lights from the lens array system, characterized in that an optical system in which the action of compressing the incident light in the direction of arrangement of the plurality of light sources is greater than the action of compressing the incident light in a direction perpendicular thereto is provided between the light sources and the lens array system. The specification also discloses a projection type display apparatus including such illuminating device.

Abstract: An optical system is provided with a pair of forward optical components each having a shutter for controlling the amount of transmission of a light from an object, an optical member for laying the optical axes of the pair of forward optical components one upon the other, and a rearward optical component disposed so that the optical axis thereof may coincide with the optical axes laid one upon the other. The optical system alternately varies the amounts of transmission of the light transmitted through the shutters of the pair of forward optical components to thereby time-serially form a parallax image.

Abstract: In an illumination apparatus for illuminating a display device with a light beam from a light source through an illumination optical system, the illumination optical system includes a first lens array unit having a plurality of positive lens portions juxtaposed with each other, a second lens array unit having a plurality of negative lens portions juxtaposed with each other, and a third lens array unit having a plurality of positive lens portions juxtaposed with each other. The first to third lens array units are sequentially arranged from the light source side. The image-side focal point of the combined system of lens portions of the first and second lens array units is located at the third lens array unit. The object-side focal point of the combined system of lens portions of the second and third lens array units is located at the first lens array unit, thereby attaining a reduction in the size of the illumination apparatus.

Abstract: The present invention has as its object to provide a projection type display apparatus which suffers little from the occurrence of the distortion of the surface of a dichroic mirror in a color combining optical system, and the occurrence of the deformation of a projected image by the angular deviation of the surface of the dichroic mirror and in which the correction of the chromatic aberration of magnification of a projection lens is stably possible during mass production. So, the color combining system of the present invention is provided with at least three prisms, two dichroic mirror layers for reflecting lights differing in wavelength area from each other, the two dichroic mirror layers being formed so as not to intersect with each other with one of the three prisms which is located most adjacent to the light exit side interposed therebetween, and at least one optical element having positive or negative refractive power.

Abstract: A color combining optical system according to this invention aims at reducing the size of an optical system and suppressing the occurrence of color unevenness. According to this invention, there is provided a color combining optical system for combining color light reflected by a dichroic film and color light transmitted through the dichroic film. The optical thickness of the dichroic film increases or decreases from one end side to the other end side in the inclining direction of the dichroic film with respect to the incident optical axis of the color light reflected by the dichroic film.

Abstract: An optical system for shooting a three-dimensional image and a three-dimensional image shooting apparatus using the optical system produces an image with a smaller amount of light leaked from the side to be cut off over an entire image frame when parallax images are obtained by employing a shutter in which the extinction ratio varies depending on an incident angle. The optical system includes a pair of front optical components each having negative optical power, an optical member for superimposing optical axes of the pair of front optical components with each other, a rear optical component disposed to have an optical axis aligned with the superimposed optical axes, and a shutter capable of independently controlling amounts of transmitted light incident upon the pair of front optical components from an object. The shutter is disposed between the pair of front optical components and the rear optical component.

Abstract: An illumination apparatus has a light-collecting reflector, a light source placed at a position of a focal point of the reflector, a first lens array for condensing light reflected by the reflector, a second lens array disposed at or near a position of a rear focal point of the first lens array, and an optical system for illuminating a surface to be illuminated, with multiple beams from the second lens array. The illumination apparatus satisfies the following condition: 0.7<K1 <1.3 where K1 =(Larc×flyf1/2fm)/(Lfly2p/2) where Larc: a length of a light-emitting portion of the light source along a direction of the optical axis, flyf1: a focal length of the first lens array, fm: a focal length of the light-collecting reflector, and Lfly2p: a length along a longitudinal direction of each lens of the second lens array.

Abstract: Provided are a color combining optical element capable of forming a good projected image on a screen surface while permitting scaling-down of entire apparatus and a projection image display apparatus using it.

Abstract: A projection lens of the following structure was invented for the purpose of providing a bright projection optical system with the F-number of approximately 2 or lower while maintaining good optical characteristics, in an image display apparatus. The projection lens is constructed of six lens units, a first lens unit L1 of a negative optical power, a second lens unit L2 of a positive optical power, a third lens unit L3 of a positive optical power, a fourth lens unit L4 of a negative optical power, a fifth lens unit L5, and a sixth lens unit L6 of a positive optical power, in the order named from the enlargement conjugate side, and four lens units (L2 to L5) out of the lens units move toward the enlargement conjugate side during zooming from the wideangle extreme to the telephoto extreme.

Abstract: A zoom lens for projecting an original image onto a screen in an enlarged scale includes, in order from the screen side, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of negative refractive power, a fourth lens unit of positive refractive power and a fifth lens unit of positive refractive power, wherein, during zooming from a wide-angle end to a telephoto end, the second lens unit and the fourth lens unit move toward the screen side.