Hitachi, Ltd.

Sega Enterprises, Ltd.

Kiyoshi Wada

Hiroki Yoshikawa

Takahiko Yoshida

Koji Hirata

Masayuki Muranaka

Isao Yoshizaki

Shigeru Mori

Shigeru Inaoka

Tooru Numata

Naoyuki Ogura

Tetsu Ohishi

Koji Suso

Toshimitsu Watanabe

Kazunari Nakagawa

Atsuo Osawa

Akira Takahashi

Yoshimasa Yokoyama

Hideo Tanide

Maki Furui

Satoshi Ishizuka

Atsuo Ohsawa

Tohru Mori

Tutomu Simada

Naoko Kubo

Kohsuke Ozeki

Yoshinori Matsumura

Yasuhiko Komatsu

A rear projection type image display apparatus having an arrangement that a projection distance of a projection lens thereof is shortened and a density of mounting of parts relating to an optical system and an electric system is made higher. Furthermore, a width of a rear portion of a housing of the rear projection type image display apparatus is reduced rearwards at any position from the upper portion to the lower portion thereof, and the lower portion of a back cover is depressed inwards. Thus, a space required to install the rear projection type image display apparatus can be reduced, the rear surface of the apparatus can be disposed on a wall without any gap when the apparatus is installed along the wall, and the overall body of the apparatus can be received deep into a corner of walls when the apparatus is installed at the corner.

Rear projection type image display apparatus

A transmission screen for a rear projection type image display apparatus having at least one image generation source for displaying images, at least one projection lens for enlarging and projecting images displayed on the at least one image generation source onto a rear portion of the transmission screen for display. The transmission screen of the image display apparatus enables display of the images projected onto the transmission screen with a contrast of at least 70. Further, the transmission screen enables display with a field angle within a range of at least 72.degree. to less than 100.degree.. The transmission screen also includes a glossy light absorbing layer and a substantially smooth mirror surface at a light exit surface thereof.

Rear projection type image display apparatus and transmission type

An ultra-wide angle liquid crystal projector system comprising a light source, a liquid crystal panel, a curved screen, and a projection lens for projecting in accordance with light emitted by the light source an image formed on the liquid crystal panel onto the curved screen. The projection lens has a curvature of field substantially conforming to the shape of the curved screen and an angle of projection of at least 120 degrees. The projection lens is disposed with respect to the curved screen so that a distance from an exit surface of the projection lens to the curved screen is less than 3 meters.

Ultra-wide angle liquid crystal projector system

In a projection lens device having at least two plastic lenses for magnification-projecting an original image displayed on a display screen onto a screen, one of the two plastic lens is convex at a center thereof toward the screen and concave at a periphery thereof, and the other lens has a weak positive refractive power toward the screen at a center thereof and a stronger positive refractive power at a periphery thereof. A variation of a lens power due to a change of a surrounding environment is cancelled out by the concave shape at the periphery of the one lens and the positive refractive power at the periphery of the other lens.

Temperature compensating lens system for projection television

Disclosed is a projection lens system for use in an optical system for magnifying and projecting original images displayed on plural image display devices onto a screen through projection lenses provided in corresponding relation to the image display devices, which projection lens system comprises plural lens elements and in which according to colors or degrees of fineness of original images, the number of constituent lenses, or the shape of lens surface, or an effective aperture of at least one constituent lens element surface, or the number of constituent lenses and the shape of lens surface, or the number of constituent lenses and an effective aperture of at least one constituent lens element surface, or the shape of lens surface and an effective aperture of at least one constituent lens element surface, or the number of constituent lenses, the shape of lens surface and an effective aperture of at least one constituent lens element surface, are changed at a time.

Video projector with optical color balance

Growing community of inventors

Yokohama, Japan

Kiyoshi Wada