Olympus Optical Company, Ltd.

Olympus Corporation

Olympus Imaging Corporation

Hiroshi Takase

Toru Fujii

Masaki Imaizumi

Hisashi Goto

Toshio Takahashi

Toshihiro Imai

Masaru Morooka

Tamotsu Koiwai

Yuko Kobayashi

Akiteru Kimura

Juro Kikuchi

Yukihiko Sugita

Keigo Matsuo

Takashi Inoue

Shinichi Dosaka

Tatsuru Kanamori

Ryuhi Okubo

Hidenori Sakurai

Daichi Murakami

Hiroyuki Kurita

Kenichi Harada

Yoshikazu Ichikawa

Hikaru Hayashi

An image pickup apparatus includes: an image pickup device that includes a pixel used for focus detection, a plurality of the pixels being arranged in a matrix; a correction memory that stores correction information used for correcting a difference in amounts of received light that depend on pixel positions of the pixels used for focus detection; a correcting section that reads the correction information to correct a pixel value of the pixel used for focus detection; and a focus detecting section that detects a focal point by using the pixel value corrected by the correcting section. Focus accuracy is increased by correcting the pixel value for an AF pixel depending on the pixel position.

Image pickup apparatus and image pickup device for performing auto-focusing

A finder optical system including an objective system, an image erecting system for erecting an object image formed by the objective system, and an eyepiece system for observing the object image. These systems are constructed of low-hygroscopic organic materials. Thus, the finder optical system can prevent transient variations of optical properties caused by hygroscopicity.

Finder optical system with low-hygroscopic organic material

A camera comprises: a photographing lens; a viewfinder lens lying behind the photographing lens so that an object to be photographed can be viewed; a first reflector mirror capable of being displaced between a first position, at which the first reflector mirror intervenes between the photographing lens and viewfinder lens so that light emanating from the photographing lens is reflected horizontally substantially at 90.degree., and a second position at which the first reflector mirror has retracted from between the photographing lens and viewfinder lens; a second reflector mirror lying by the side of the first reflector mirror so that the light emanated from the photographing lens and reflected from the first reflector mirror is reflected vertically substantially at 90.degree.; an image forming plane lying below the second reflector mirror so that the light emanated from the photographing lens and reflected from the second reflector mirror forms an image thereon; and an aperture for determining a picture size that defines a zone to be exposed of film lying on the image forming plane.

Camera

A real image mode variable magnification finder optical system comprising an objective lens system including a rotatable prism, an image erecting optical system for erecting an image formed by the objective lens system and an eyepiece lens system having a positive refractive power. The prism is rotated 180.degree. for changing the finder optical system between a wide angle condition and a telephoto condition. This variable magnification finder optical system permits minimizing a space required for operating an optical member for changing a magnification thereof and composing the objective lens system compactly of a small number of component parts.

Real image mode variable magnification finder optical system

A switching variable magnification finder includes an objective lens system having a positive refracting power, an image erecting optical system for erecting an image formed by the objective lens system, and an eyepiece system having a positive refracting power, in which an auxiliary lens system is removably disposed behind the objective lens system so that magnification is varied according to the insertion or removal of the auxiliary lens system. Thus, the switching variable magnification finder allows magnification to be changed without increasing the overall of the finder optical system and moving the objective lens system and its switching mechanism to be simplified.

Switching variable magnification finder

The reflecting mirror for leading the image forming light bundle emitted from an image pickup optical system to an image forming surface has an area for reflecting the effective image forming light bundle, and another marginal area which is located outside said area, and has a reflecting characteristic different from that of said area and varying gradually outward. Accordingly, the reflecting mirror is capable of blurring the boundary of the veiling glare and reducing appearance of detrimental images. The variation of the reflecting characteristic on said outside marginal area can be realized by varying reflectance or light diffusing characteristic of the outside marginal area.

Image pickup optical system

A vari-focal lens system with switchable auxiliary lens units comprising a master lens system, an auxiliary lens unit removably arranged after the master lens system and another auxiliary lens unit removably arranged after said auxiliary lens unit, said vari-focal lens system being so adapted as to permit photographing at multiple different focal lengths by speedy switching operation with a simple mechanism.

Vari-focal lens system with switchable auxiliary lens units

A rear conversion lens system to be used for varying the focal length being inserted to the space between an objective for a single-lens reflex camera and film surface, the rear conversion lens system comprising a first lens component arranged as a positive lens, a second lens component arranged as a negative lens, a third lens component arranged as a positive meniscus lens, a fourth lens component arranged as a biconcave lens, and a fifth lens component arranged as a positive cemented doublet, the rear conversion lens system being arranged that the magnification is higher than 1.6 and aberrations are corrected favorably.

Rear conversion lens system

A vari-focal photographic lens system of rear lens group exchange type comprising a front lens group and a rear lens group and arranged to vary the focal length of the lens system as a whole by exchanging the rear lens group for another rear lens group having a different lens configuration, the vari-focal photographic lens system being arranged so compactly and arranged that the variation of aberrations is small.

Vari-focal photographic lens system of rear lens group exchange type

A varifocal lens system equipped with an auxiliary lens group comprising a master lens system consisting of a front lens group having positive refractive power and a rear lens group having negative refractive power, and an auxiliary lens group arranged in such a manner that it can be freely inserted and removed, for varying focal length, between said front and rear lens groups. Said varifocal lens system is equipped with a simple mechanism capable of varying focal length of said lens system in a very short time.

Varifocal lens system

A vari-focal photographic lens system of lens group exchange type comprising, in the order from the object side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, and a third lens unit having negative refractive power, the vari-focal photographic lens system being arranged to vary the focal length thereof by exchanging the second lens unit for another second lens unit having different lens configuration.

Vari-focal photographic lens system of lens group exchange type

A compact vari-focal photographic lens system comprising a master lens system and an auxiliary lens group wherein the master lens system comprises a front lens unit having positive refractive power and a rear lens unit having negative refractive power, the compact vari-focal photographic lens system being arranged to vary the focal length of the lens system as a whole by inserting and removing the auxiliary lens group to and from the image side of the master lens system and arranged that the overall length of the lens system is short, it is possible to vary the focal length without moving the stop mechanism, and aberrations are corrected satisfactorily favorably, the compact vari-focal photographic lens system being suitable for the use with popular cameras.

Compact vari-focal photographic lens system

Indicating device for indicating data within the visual field of

A wide-angle zoom lens system comprising a front lens group consisting of a first negative meniscus lens component, a second negative lens component and a third positive lens component, and a rear lens group consisting of a fourth positive lens component, a fifth positive meniscus lens component, a sixth negative lens component and a seventh positive lens component. Said zoom lens system is so adapted as to perform the zooming operation by varying the airspace reserved between said front and rear lens groups.

Wide angle zoom lens system

A photographic lens system is constituted of four lens components and four lens elements, comprising a first lens component of a meniscus positive lens with its convex surface on the object side, a second lens component of a biconcave lens, a third lens component of a biconvex lens and a fourth lens component of a meniscus negative lens with its convex on the image side. It is so arranged that the shortening of the focal length in such a manner that the image quality is kept good over a wide angle of field of view and the reducing of the telephoto ratio are well balanced so as to enable provision of a very compact photographic lens system having superior characteristics.

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Hachioji, Japan

Hiroshi Takase