Hitachi, Ltd.

Nippon Hoso' Kyokai

Shigehiko Takayama

Masakazu Fukushima

Masanori Maruyama

Mitsuhiro Kurashige

Hitomi Suzuki

A screen for a liquid crystal projector is provided on which an image formed by the output light from a liquid crystal projector can be recognized even in the presence of extraneous light. The screen is used for a color liquid crystal projector for projecting an image formed on a liquid crystal onto the screen by causing the light from a light source to be transmitted through or reflected from the liquid crystal. Lippman-type holograms (BS, GS, RS) having great reflectances with respect to only the wavelength band of output light of the liquid crystal projector are formed on the screen. As the screen reflects substantially only the output light of the liquid crystal projector and absorbs light having other wavelengths, the reflection of extraneous light is suppressed as much as possible. Therefore, the image projected by the liquid crystal projector is recognizable even in the presence of extraneous light.

Screen for liquid crystal projector

A one-gun three-beam electron gun comprises a triode part controlling an electron source generating a plurality of electron beams and emission of the electron beams generated by the electron source; a main electron lens of bi-potential focusing type consisting of not less than two cylindrical electrodes focusing the plurality of electron beams emitted by the triode part; electrostatic deflection plates disposed on the screen side of the main electron lens; and electrostatic deflection plates disposed on the electron source side of the main electron lens.

Electron gun with bi-potential focusing lens and electrostatic

A magnetic-focus electrostatic-deflection image pickup tube utilizes a magnetic field for electron beam focusing and an electrostatic field for electron beam deflection. The magnetic field generated by a magnetic focus coil is distributed on the tube axis to have the peak of intensity which is offset toward the electron gun. The electron beam can be deflected and focused to provide a minimized beam spot with less distortion.

Image pickup tube

An electron beam focusing lens comprises at least two cylindrical electrodes one of which is to be applied with a high potential and the other of which is to be applied with a low potential. A plate electrode having an aperture at a central portion thereof is provided at an end face of the high-potential cylindrical electrode opposite to the low-potential cylindrical electrode. The plate electrode may be of a circularly curved shape which is projected toward the low-potential cylindrical electrode between the outer and inner circumference of the plate electrode.

Growing community of inventors

Mitaka, Japan

Shigehiko Takayama