Hitachi, Ltd.

Nec Corporation

Terminus Technology Limited

Hitachi Consumer Electronics Co., Ltd.

Other

Hitachi Maxell, Limited

Sega Enterprises, Ltd.

Naoyuki Ogura

Koji Hirata

Masahiko Yatsu

Shigeru Mori

Kazunari Nakagawa

Hidehiro Ikeda

Hiroki Yoshikawa

Yasuo Otsuka

Takahiro Yoshida

Takanori Hisada

Tetsu Ohishi

Shuji Kato

Masayuki Fukui

Mikio Shiraishi

Tutomu Murase

Toru Numata

Atsuo Osawa

Shigeru Inaoka

Masanori Tsumura

Nobuo Masuoka

Daisuke Imafuku

Tomoharu Nakiri

Chihiro Egawa

Megumi Kurachi

Chohei Ono

Masayoshi Kobayashi

Atsushi Kuriyama

Masayuki Muranaka

Isao Yoshizaki

Kiyoshi Wada

Hideo Tanide

Yuriko Inadachi

A projection type display apparatus including an oblique projection optical system having a plurality of lenses is disclosed. A lens nearest to a projection screen has a vertical effective image area through which a light flux passes. The lens is arranged at a position not including an optical axis shared by the largest number of lenses among the plurality of lenses. A flat mirror for returning the optical path is arranged between the particular lens and the projection screen at a predetermined angle to the optical axis. An enlarged image obtained by the light flux returned by the flat mirror is formed toward a display screen.

Oblique projection optical system and projection type display apparatus using the same

There is provided a projection image display apparatus which is excellent in quality of a display screen image even if a projection lens using a plastic lens having an asymmetrical shape with respect to an optical axis is used. The apparatus includes a projection lens which obliquely projects video light on a screen, an integrator which aligns a polarization direction of light from a light source, and an image display element (P, PL) which modulates light having the aligned polarization direction by an image signal. The projection lens includes multiple plastic lenses, and each of the multiple plastic lenses is arrayed, respectively, by shifting a gate direction to each other by 180 degrees. When the projection lens includes n sheets (n is a natural number) of plastic lenses, each of the multiple plastic lenses may be arrayed, respectively, by shifting a gate direction to each other by (360/n) degrees.

Projection image display apparatus having a first lens and a second lens adjacent to the screen

An object of the invention is to reduce the size and weight of a video projector by shortening the length of the arm of a mirror rotator and reducing the size of a mirror. A video projector comprises a plurality of projection lenses through which image light rays from a liquid crystal panel are extracted in a magnified manner; a reflective mirror for reflecting the extracted image light rays onto a screen; and a mirror rotator for rotating the reflective mirror so that the extracted image light rays can be reflected in particular directions. Among the projection lenses, some of the projection lenses located farther away from the liquid crystal penal are partially cut such that areas through which the image light rays do not pass are cut off to create a lens cut-off space. The mirror rotator is placed in the lens cut-off space.

Video projector which obliquely projects images onto screen

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 lensas 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.

Projecting optical unit and projecting type image display apparatus therewith

An associative memoryfor primary searching operation of an associative memorysupplies a valid state to a primary match linecorresponding to storage data coincident with search datataking mask information into account, and supplies a value obtained from a result of a logical sum operation (an OR operation), with a valid state for the storage data as true, of all said coincident storage data to a counting meansas intermediate data. The counting meanssupplies a result of an operation to the intermediate datafor counting the number of bits in an invalid state for the storage data to an associative memoryfor secondary searching operations as secondary search data. Among secondary storage data obtained by carrying out said operation to said storage data, the associative memoryfor secondary searching operation supplies a result of carrying out the searching operation of the secondary search datato a secondary match line. The invalidation meanschanges a secondary match linecorresponding to a primary match linein an invalid state into an invalid state to supply to an external source as a match line

Associative memory having a mask function for use in a network device

Lens for projector

Mirror for projector

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.

Projection display, projection optical system and transmission lens or free curved lens

An image that has been displayed on the display screen of an image generator is first passed through a projection lens section consisting of a front group and a rear group. Next after being reflected on the reflecting surface of a free-form surface mirror, the image is further reflected by a planar reflecting mirror and then obliquely projected from the lower section of a projection screen onto the screen. The front group of the projection lens section is provided for enlarging the image. In order to correct aberration due to oblique projection onto the projection screen, the rear group uses a free-form surface lens that forms a concave shape with respect to the exit side of light from the lens. The free-form surface mirror corrects trapezoidal distortion due to oblique projection onto the projection screen. The free-form surface lens in the rear group of the projection lens section can accommodate changes in environmental conditions by using one edge as a reference edge and rendering the other edge expandable. The free-form surface mirror can likewise use one edge as a reference edge and render the other edge expandable. For adjustment, the free-form surface mirror can also be pivoted about the reference edge.

Projection type image display

Growing community of inventors

Machida, Japan

Naoyuki Ogura