Hitachi, Ltd.

Other

Hiatchi, Ltd.

Hitachi, Ltd., and Hitachi Video and Information Systems, Inc.

Tomohiro Miyoshi

Taro Imahase

Masahiko Yatsu

Yasuo Otsuka

Takesuke Maruyama

Satoshi Ohuchi

Satoshi Ouchi

Futoshi Yamasaki

Nobuyuki Kaku

Atsushi Ishibashi

Shigehisa Hagura

Takeshi Hoshino

Kenji Fuse

Naohiro Ozawa

Masaharu Deguchi

Takashi Kakuda

Yutaka Matsuda

Makoto Fukatsu

Seiichi Sekiguchi

Fukuyasu Abe

Takuya Shiaki

Mikiharu Kuwata

Nobuhiko Konuma

Hidetomo Yoshimura

Koichi Umezawa

Koji Hirata

Tetsu Ohishi

Tsutomu Nakashima

Hiroki Yoshikawa

An image display device includes a light source which outputs a first light including a first color light, a second color light and a third color light, a polarity converter which unifies polarities of the first light into a single polarity, a dichroic mirror which separates the first color light from the first light which is output by the polarity converter, and first to third reflective liquid crystal display elements, respectively, installed for the first to third color lights. First to third polarized beam splitters are provided together with first and second wavelength selective polarity rotator elements. A projection lens is provided so as to project a light combined by the third polarized beam splitter, and the first color light, which is reflected by the first reflective liquid crystal display element, permeates the first polarized beam splitter and the third polarized beam splitter.

Image display device

The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Optical unit and image display apparatus

A projection type image display apparatus includes a light source to emit light; a polarizing beam splitter to polarize the light received from the light source; a first lens array including a plurality of first lens cells having rectangular shapes to receive the light from the polarizing beam splitter, each first lens cell having a first side and a second side, the first side being longer than the second side, the first lens array having a rectangular shape, the first lens array having a third side and a fourth side, the third side being longer than the fourth side, the first sides of the first lens cells and the third side of the first lens array extending along a first direction; a second lens array including a plurality of second lens cells and being configured to receive the light from the first lens array, the second lens array having a rectangular shape and having a fifth side and a sixth side, the fifth and sixth sides of the second lens array having substantially the same dimensions as the third and fourth sides of the first lens array; a color separator configured to separate the light from the second lens array into a plurality of light rays of different colors; an image display device configured to form an optical image from the plurality of light rays; and a projector configured to project the plurality of light rays emitted from the image display device as a color image.

Projection type image display apparatus

A liquid crystal projector comprises an illuminating optical system including a light source, a color separating optical system for separating illuminating light rays emitted by the illuminating optical system into light rays of three colors, a projection lens unit comprising a projection lens, a cross dichroic prism disposed near a light receiving end of the projection lens, and a plurality of liquid crystal panels arranged around the cross dichroic prism, and a light source power supply for supplying power to the light source. The projection lens unit, the color separating optical system, the illuminating optical system and the light source power supply are arranged in that order. The liquid crystal projector has an outside size in a horizontal plane of 263 mm by 318 mm or below. The liquid crystal panels have a display screen size of 0.9 in. A cooling fan for cooling the plurality of liquid crystal panels is disposed beside the projection lens.

Liquid crystal projector, and projection lens unit, optical unit and cooling system for the same

Disclosed is a compact, light, inexpensive reflection type liquid crystal projector optical unit or reflection type liquid crystal projector which provides high brightness without contrast deterioration caused by light leakage associated with black image display. The unit or projector uses, as a polarizer/analyzer for a reflection liquid crystal panel, a reflection polarizing plate which functions as a polarizing plate by its grating function only in a specific direction. It also uses an auxiliary polarizer and an absorption auxiliary analyzer. Their reflection axis or absorption axis is adjusted according to the characteristic of the reflection liquid crystal panel so as to minimize light leakage associated with black image display.

An image display device has three reflective image display elements for red, green and blue to form an optical image according to a video signal from light output from a light source, and an optical system to supply light onto the display elements and to combine and output the light reflected from the display elements. The image display device includes a first polarity converting unit to convert luminous flux from the light source to S polarized light, a first polarized beam splitter, and second polarized beam splitter. The reflective image display element for green is provided in a vicinity of the first polarized beam splitter, and the light reflected by the first polarized beam splitter and input to the reflective image display element for green is S polarized light. The light output from the reflective image display element for green permeates the first and second polarized beam splitters.

An image display technique which projects R, G, and B light rays on a display device to form an image with an increased utilization ratio of light and an increased screen brightness. R, G, and B light rays as a result of color separation are reflected by plural reflective surfaces on the inner side, etc. of a rotary polyhedral reflector, so that, as the reflector rotates around a central axis and its reflection plane sequentially changes from one reflective surface to a next one, the reflected light rays are projected on a display device surface in different positions and scroll in a prescribed direction.

A projection-type display apparatus is improved in contrast by an overlap between a band of light to be cut off by a notch filter and a band of light wavelengths to which the polarization converting efficiencies of first and second specific-wavelength converter elements are 50%, respectively.

Projection-type video display

A projection type image display apparatus includes a light axis moving unit for moving a direction of a light from a light source substantially in parallel periodically at a predetermined rate, a light separating unit for separating the light from the light axis moving unit into a plurality of color light components of predetermined wavelength bands, and a radiation unit for radiating the color light components from the light separating unit on an image display device, projecting an optical image corresponding to the image signal in enlarge form.

Growing community of inventors

Fujisawa, Japan

Tomohiro Miyoshi