Abstract: A projection type image display apparatus includes a lens group, being disposed adjacent to an image display element, which is configured to include a plural number of lenses, and a mirror, which is configured to reflect emission lights from the lens group, so as to project upon the screen obliquely. A ratio (Lo/Lp) between a distance (Lp) from a center of the mirror up to the screen and a diagonal size (Lo) of the screen is at least 2.

Abstract: A display apparatus comprises a lighting unit for emitting a light, and a first light modulation unit for forming an image through modulation of the light from a light source unit, wherein the lighting unit includes a light source for emitting the light, a second light modulation unit for modulating the light from the light source, being smaller than the first light modulation unit for modulating the light from the light source, and a projection unit for projecting the light modulated through the second light modulation unit, enlargely, upon the first light modulation unit for use of display.

Abstract: In a projection type display apparatus for enabling to display an image, by projecting an image on an image display element(s), enlargedly, upon a nearly horizontal surface, such as, a table, a reflection mirror for reflecting a light from a light source is so disposed that an optical axis of the light source is nearly perpendicular to an optical axis of a lens group having a plural number of lens elements, which are disposed symmetric with respect to the optical axis.

Abstract: In a projection type display apparatus for enabling to display an image, by projecting an image on an image display element(s), enlargedly, upon a nearly horizontal surface, such as, a table, a reflection mirror for reflecting a light from a light source is so disposed that an optical axis of the light source is nearly perpendicular to an optical axis of a lens group having a plural number of lens elements, which are disposed symmetric with respect to the optical axis.

Abstract: A projection optical unit for a projection display apparatus, which displays an image upon a projection surface, obliquely, includes a front lens group disposed in a direction from an image display element to a projection surface, a rear lens group, and a reflection mirror formed so that a curvature of a portion for reflecting a light beam incident upon a lower end portion of the projection surface is larger than a curvature of a portion for reflecting a light beam incident upon an upper end of the projection surface. An optical axis of the front lens group and the rear lens group is more inclined with respect to a direction of the portion of the reflection mirror for reflecting the light beam incident upon the lower end portion of the projection surface than a normal line direction of the image display element.

Abstract: A projection type image display apparatus includes an image display element, a first lens group disposed in a light direction with respect to the image display element and configured to include a plurality of lenses, a second lens group disposed in a light direction with respect to the first lens group and configured to include a plurality of lenses, a reflection mirror, configured to reflect lights emitted from the first and/or second lens groups so as to project upon the screen obliquely, a first mounting base on which the first lens group is mounted, a second mounting base on which the second lens group is mounted, and a chassis configured to store the first and second lens groups, the reflection mirror, and the first and second mounting bases. The first mounting base is fixed at a bottom of the chassis, while the second mounting base is moveable.

Abstract: A projection-type image display apparatus for projecting an image, enlargedly, onto a projection surface, comprises: an image display element; a lens group, being disposed behind the image display element, comprising therein, a front lens group made up with a plural number of lenses, including, at least, a refractive lens, and a rear lens group made up with a plural number of lenses, including, at least, a lens having a free curved surface configuration and being rotationally asymmetric, thereby emitting an image displayed on the image display element; a reflection mirror for reflecting the light from the lens group, thereby projection onto the projection surface, obliquely; and a movement member for moving the plural number of lenses of the rear lens group.

Abstract: A projection optical unit for a projection display apparatus, which displays an image upon a projection surface, obliquely, includes a front lens group disposed in a direction from an image display element to a projection surface, a rear lens group, and a reflection mirror formed so that a curvature of a portion for reflecting a light beam incident upon a lower end portion of the projection surface is larger than a curvature of a portion for reflecting a light beam incident upon an upper end of the projection surface. An optical axis of the front lens group and the rear lens group is more inclined with respect to a direction of the portion of the reflection mirror for reflecting the light beam incident upon the lower end portion of the projection surface than a normal line direction of the image display element.

Abstract: A projection type image display apparatus includes an image display element, a first lens group disposed in a light direction with respect to the image display element and configured to include a plurality of lenses, a second lens group disposed in a light direction with respect to the first lens group and configured to include a plurality of lenses, a reflection mirror, configured to reflect lights emitted from the first and/or second lens groups so as to project upon the screen obliquely, a first mounting base on which the first lens group is mounted, a second mounting base on which the second lens group is mounted, and a chassis configured to store the first and second lens groups, the reflection mirror, and the first and second mounting bases. The first mounting base is fixed at a bottom of the chassis, while the second mounting base is moveable.

Abstract: A projection type image display apparatus includes an image display element, and a projection optical unit, which is configured to project an image displayed on the image display element, enlargedly, upon a screen. The projection optical unit includes a lens group, which is configured to compensate an distortion on an image surface on the screen, a mirror for compensating a trapezoidal distortion on the screen. The mirror reflects lights emitted from the lens group, so as to project upon the screen obliquely.

Abstract: A projection type image display apparatus includes a lens group, being disposed adjacent to an image display element, which is configured to include a plural number of lenses, and a mirror, which is configured to reflect emission lights from the lens group, so as to project upon the screen obliquely. A ratio (Lo/Lp) between a distance (Lp) from a center of the mirror up to the screen and a diagonal size (Lo) of the screen is at least 2.

Abstract: A projection optical unit for obliquely projecting an image displayed on an image display element upon a projection surface, enlargedly, comprises: a lens group, being disposed neighboring to the image display element, and including a plural number of projection lenses therein; and a reflection mirror for reflecting lights emitting from the lens group, to be projected onto the projection surface, obliquely, wherein assuming that a light beam, emitting from a center of the display screen of the image display element, passing through a center of an entrance pupil of the lens group, and entering into a screen center on the projection surface, is a screen center light beam, then the screen center light beam is incident upon the projection surface, obliquely, with respect to a normal line thereon, the lens group comprises a front lens group including a plural number of refraction lenses, being disposed thereafter directing from the image display element to the projection surface and having rotationally symmetric s

Abstract: A projection-type image display apparatus for projecting an image, enlargedly, onto a projection surface, comprises: an image display element; a lens group, being disposed behind the image display element, comprising therein, a front lens group made up with a plural number of lenses, including, at least, a refractive lens, having a positive power and being rotationally symmetric in a surface configuration thereof, and a rear lens group made up with a plural number of lenses, including, at least, a lens having a free curved surface configuration and being rotationally asymmetric, thereby emitting the image displayed on the image display element; a reflection mirror for reflecting the light from the lens group, thereby projection onto the projection surface, obliquely; and a movement member for moving the plural number of lenses of the rear lens group.

Abstract: A projection-type image display apparatus for projecting an image, enlargedly, onto a projection surface, comprises: an image display element; a lens group, being disposed behind the image display element, comprising therein, a front lens group made up with a plural number of lenses, including, at least, a refractive lens, having a positive power and being rotationally symmetric in a surface configuration thereof, and a rear lens group made up with a plural number of lenses, including, at least, a lens having a free curved surface configuration and being rotationally asymmetric, thereby emitting the image displayed on the image display element; a reflection mirror for reflecting the light from the lens group, thereby projection onto the projection surface, obliquely; a first mounting base, on which the rear lens group is mounted; and a rod member, which is provided on the mounting base for moving the mounting base.

Abstract: A projection-type display apparatus, comprises a front lens group having a plural number of lenses, each having rotationally symmetric surface configuration, a rear lens group, being disposed in rear of the front lens group, including a refractive lens for diverting a light and having a rotationally symmetric surface configuration, and a plural number of free curved surface lenses, each having a rotationally asymmetric free curved surface configuration, and a reflection mirror, being disposed in rear of the rear lens group, having a convex configuration into a direction of reflection of light and a rotationally asymmetric free curved surface configuration, at least in a part thereof.

Abstract: A Fresnel lens sheet used for an image display device is disclosed. The Fresnel lens sheet is provided with a first prism group in an area of a light entrance plane of the Fresnel lens sheet where the incident angle of light is equal to or more than a predetermined incident angle and a second prism group in an area of a light entrance plane of the Fresnel lens sheet where the incident angle of light is less than the predetermined value.

Abstract: A projection display is capable of suppressing both the trapezoidal distortion of an enlarged image projected on a screen by oblique projection and aberrations resulting from oblique projection and includes a projection optical system provided with lenses that can be easily manufactured and assembled. The projection optical system for obliquely projecting an image formed by a display device on the screen includes a free curved lens having a rotationally asymmetric free curved surface. The free curved lens has fringing parts having outlines of a shape coinciding with an arc of a circle having the center on the optical axis of the free curved lens.

Abstract: A projection image display device is disclosed in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lens 2 as a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.

Abstract: In a projection type image display apparatus, for enlarging an image on a image display apparatus 1 by means of a projection lens 2, thereby projecting the enlarged image onto a screen 6, obliquely, being inclined thereto, between the projection lens 2 and a rear-surface mirror 5, there are disposed free shaped surface mirrors 3 and 4, each having a free shaped surface for compensating a trapezoidal distortion due to oblique projection of the enlarged image. The surface configuration of the free shaped surface mirror is so shaped as to satisfy a following equation: |L1?L2|>1.4·Dv if assuming that a distance for a light beam of an upper end of the enlarged image to reach the screen after being reflected upon a free shaped surface is “L1”, a distance for a light beam of a lower end of the enlarged image to reach the screen after being reflected upon the free shaped surface is “L2”, and a distance from an upper end of an image on the screen to a lower end thereof is “Dv”.

Abstract: Both ends of a transparent cover which is formed of a curved member are fitted to a lens guard and a mirror guard, and a free-shaped surface mirror and a free-shaped surface lens are housed in a sealed space defined within a projection type image display device.