Hitachi, Ltd.

Kaoru Yanagawa

Toshio Miyazawa

Kentaro Hanma

Katsuhide Aoto

The optical system comprises three reflection liquid crystal panels, polarization spliters PBS-R, PBS-G PBS-B which polarize components of an incident light to be reflected by the respective reflection liquid crystal panels, color separation and composition elements. The polarization splitters further separate the polarization converted output light in either an outputting direction or a non-outputting direction corresponding to the polarization, and the color separation and composition elements are arranged as separate elements in terms of optical path and in such a manner that these elements are disposed adjacent to each other in terms of space.

System for a compact projection display using reflection type liquid crystal panels

A color liquid crystal projector has an optical system for color splitting. The optical system includes a mirror for reflecting a first primary-color light and transmitting second and third primary-color lights in light from a light source; a first phase plate for transmitting the second primary-color light from the mirror with its polarization degree rotated through 90&deg;, and for transmitting the third primary-color light; a first prism for transmitting the second primary-color light from the first phase plate into a second liquid crystal display panel, and reflecting the third primary-color light from the first phase plate into a third liquid crystal display panel; a second prism for entering the first primary-color light from the mirror into a first liquid crystal display panel; and a dichroic prism for combining the first, second and third primary-color lights reflected from the liquid crystal display panels.

Color liquid crystal projector having an improved optical system

This invention relates to automatic focusing systems for video cameras and, more particularly, to an automatic focusing system, which is adopted to effect a focusing operation such as to render maximum the output of a detector detecting a high frequency component of a video signal.

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Ichinomiya, Japan

Kaoru Yanagawa