Nittoh Inc.

Nittoh Kogaku K.k.

Takahiko Matsuo

Takafumi Hanaoka

Takuya Fujimatsu

Masashi Yoshida

An image formation optical system includes a first optical system, in which a first refractive system is arranged toward the reduction side of an intermediate image and a second refractive system is arranged toward the magnification side of the intermediate image, and the first refractive system has a first stop, and the second refractive system has a second stop. Lens surfaces are arranged next to and both toward the reduction side and toward the magnification side of the first stop and the second stop, and the following condition is satisfied:1.5<1-1 (unit of mm), where

Image-forming optical system, projection device, and imaging device

An optical system includes a first optical subsystem disposed on an enlargement side and a second optical subsystem disposed on a reduction side with an intermediate image in between. The first optical subsystem includes: a first lens group that is disposed on the enlargement side of a first stop with a first distance, in which other lenses could be disposed but no other lenses are disposed, and is provided on the enlargement side with a first component with negative refractive power; and a second lens group that has positive refractive power, is disposed on the reduction side of the first stop with a second distance, in which other lenses could be disposed but no lenses are disposed, and forms the intermediate image so as to be adjacent on a reduction side of the second lens group and so as to be tilted toward the enlargement side.

Optical system having intermediate image formed therein

In a projection optical system for projecting an optical image from a first image plane on a reduction side onto a second image plane on a magnification side, the system includes an achromatic lens including a positive lens and a negative lens separately arranged in this order from the reduction side toward the magnification side, and the negative lens having a refractive index of 1.7 or higher and an Abbe's number of 55 or less satisfies the following expression:3.5&#x2264;|&#x2003;&#x2003;(1),where the radius of curvature of a light incident surface is R and the focal length of an entire projection optical system is f.

Projection optical system and projector apparatus

A projection optical projects from a first image plane on a reducing side onto a second image plane on a magnifying side includes: a first optical system with a plurality of lenses that forms a first intermediate image on a first side of an optical axis inside the first optical system by light that is incident from the reducing side, into a second intermediate image on a second side of the optical axis at a position closer to the magnifying side than the first optical system. A second optical system includes a first reflective surface with positive power that is positioned closer to the magnifying side than the second intermediate image. The first optical system includes an intermediate lens. The first intermediate image is formed to be inclined to be closer to the reducing side as a distance from the optical axis increases so as to straddle the intermediate lens.

Projection optical system and projector

A projection optical system () projects from a DMD () on a reducing side onto a screen () on an enlargement side, and includes: a first refractive optical system () that forms a first intermediate image () on the enlargement side using light incident from the reducing side; a second refractive optical system () that forms the first intermediate image () on the reducing side into a second intermediate image () on the enlargement side; and a first reflective optical system () including a first reflective surface () with positive refractive power that is positioned on the enlargement side of the second intermediate image (), wherein the second refractive optical system () includes a first focus lens group () that moves when focusing is carried out, and the first focus lens group () includes at least one lens (L) included in the second refractive optical system ().

In order to provide a projection lens barrel and a projection display device that are capable of correcting the optical characteristics of a plurality of lens groups, a projection lens barrel, comprising a lens optical system causing light from an image display element to be formed as a projected image on a screen, also comprises correction mechanisms that move each of at least two lens groups along an optical axis and correct the optical characteristics to be corrected, said lens groups each having different optical characteristics for correction in order to suppress reduction in image quality of a projected image caused by changes in optical characteristics caused by temperature changes in the projection lens barrel.

Projection lens barrel and projection display device

A projection optical system () that projects from a first image plane on a reducing side to a second image plane on an enlargement side, including a first refractive optical system () that includes eight lenses (L) to (L) and forms a first intermediate image () on the enlargement side using light that is incident from the reducing side, a second refractive optical system () that includes six lenses (L) to (L) and forms the first intermediate image () on the reducing side into a second intermediate image () on the enlargement side, and a first reflective optical system () that includes a first reflective surface () with positive refractive power that is positioned closer to the enlargement side than the second intermediate image ().

Projection optical assembly and projector device

A projection optical system () projects from a first image plane () on a reducing side to a second image plane () on an enlargement side. The projection optical system () includes a first optical system () that includes a plurality of lenses and forms a first intermediate image () formed inside the first optical system () by light incident from the reducing side into a second intermediate image () on the enlargement side of the first optical system; a second optical system () that includes a first reflective surface (M) with positive refractive power which is positioned further to the enlargement side than the second intermediate image (); and a glass block () that is disposed between the first optical system () and the first reflective surface (M), the glass block () passing light rays from the first optical system to the second intermediate image.

A projection optical system () projects from a first image plane () on a reducing side to a second image plane () on an enlargement side. The projection optical system () includes a first optical system () that includes a plurality of lenses and forms a first intermediate image () formed inside the first optical system () by light incident from the reducing side into a second intermediate image () on the enlargement side of the first optical system (); a second optical system () that includes a first reflective surface (M) with positive refractive power which is positioned further to the enlargement side than the second intermediate image (); and a glass block () that is disposed between the first optical system () and the first reflective surface (M), the glass block () passing light rays from the first optical system () to the second intermediate image ().

There is provided a projection optical system () that projects from a first image plane on a reducing side to a second image plane on an enlargement side, including a first refractive optical system () that includes eight lenses (L) to (L) and forms a first intermediate image () on the enlargement side using light that is incident from the reducing side, a second refractive optical system () that includes six lenses (L) to (L) and forms the first intermediate image () on the reducing side into a second intermediate image () on the enlargement side, and a first reflective optical system () that includes a first reflective surface () with positive refractive power that is positioned closer to the enlargement side than the second intermediate image ().

Projection optical assembly with multiple refractive optical systems and related projector device

A projection lens system has first, second and third lens groups. The first lens group with combined focal length fhas, in order from a screen side, a first negative meniscus lens, a second negative meniscus lens with focal length f, refractive index nand screen side surface radius of curvature R, and a negative biconcave lens with focal length f. A second lens group consists of a positive biconvex lens with a radius of curvature Rof a surface on a light modulator side of the positive biconvex lens. The system satisfies the following conditions: 1.0&#x3c;|f/f|&#x3c;4.0; 5.0&#x3c;|f/f|&#x3c;9.0; 1.75&#x3c;n&#x3c;2.0; and 0.1&#x3c;|R/R|&#x3c;0.8.

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Nagano, Japan

Takahiko Matsuo