Nikon Corporation

Yoshiro Oikawa

Tetsuo Hattori

Masaaki Kusano

Motoi Ueda

Kiyoshi Numazaki

Hideaki Shimomura

Naotaka Shimamura

Masatoshi Sato

Takeshi Hasegawa

Mikio Okamoto

Kazufumi Ishibashi

Nobuyuki Kikuchi

The projection type display apparatus according to the present invention has a prism for separating incident light into a plurality of light components and combining the plurality of modulated color components. The prism is constituted by a plurality of prism assemblies, each including an optical member made of an optically transparent material having a photoelastic constant whose absolute value is not greater than &plus;1.5&times;10 cm /N with respect to the incident light. More preferably, these plurality of prism assemblies are arranged such that each of a plurality of the separated color components is totally reflected by any of the prism assemblies.

Projection type display apparatus

The present invention relates to a projection type display apparatus which utilizes a polarizing beam splitter and/or a color separating/combining optical system, each being constituted by an optically transparent material block having a specific characteristic, thereby being capable of securing optically stable performances against influences of various thermal and external stresses and suppressing image quality deterioration to a low level. In particular, in this projection type display apparatus, the polarizing beam splitter used for a polarized light separating optical system and analyzing optical system, and/or an optical member servicing as a color separating/combining optical system are constituted by an optically transparent material block in which a wavelength where the absolute value of a photoelastic constant becomes a minimum level exists in a wavelength range of a blue light component.

A projection type display apparatus includes a spatial light modulator, a polarizing beam splitter formed of members of a transparent material, and a projection optical system. The polarizing beam splitter includes a dielectric multilayer film, and a first transparent material member and a second transparent material member sandwiching the dielectric multilayer film. Each of the first and second transparent material members is made of a transparent material with a refractive index of at least 1.8 and with an absolute value of the photoelastic constant being no more than 1.5.times.10.sup.-8 cm.sup.2 /N for light of wavelengths 0.4 .mu.m to 0.7 .mu.m, incident to the polarizing beam splitter.

Methods and apparatus are disclose for obtaining a bright projected color image. In a representative apparatus, polarized beam splitters (one for each primary color of an image to be projected) separate p-polarized light and s-polarized light for each of the primary colors. Each separated s- and p-polarized light for each color enters a respective spatial light modulator. For each primary color, modulated light fluxes produced by the two spatial light modulators, which perform modulation of the same image, are analyzed and integrated by the polarized beam splitters. The analyzed and integrated light fluxes for each primary color are color integrated, either by projection using separate projection lenses for each color, or by a cross-dichroic prism followed by projection using a single lens.

Projection-display apparatus and method providing improved brightness of

A shutter has a cylindrical take-up member rotatable about the central shaft thereof, and a thin board having one end portion thereof fixed to the outer peripheral surface of the take-up member and deformable into a state rolled on the outer peripheral surface of the take-up member and having a spring force for returning to a flat state. The thin board is capable of operating between a liberating position in which in conformity with the rotated position of the take-up member, it is rolled onto the take-up member and retracts from a predetermined optical path to thereby permit the passage of light in the optical path and an intercepting position in which it is unrolled from the take-up member and assumes a flat shape and protrudes into the predetermined optical path to thereby intercept the light.

Shutter for display device of projection type

A camera according to the present invention is so arranged that a half mirror is disposed in an optical path between a taking lens and a photographic film strip to be exposed so as to reflect a part of subject image incident thereinto. The thus reflected subject image is received by CCD, which converts it into electric image data. The image data is converted into binary codes, and the codes are written by a magnetic head in a magnetic layer provided on the back face of the photographic film strip. On the other hand, the image data received by the CCD is displayed for a photographer in a finder through a liquid crystal display at all times.

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Tokyo, Japan

Yoshiro Oikawa