Olympus Optical Company, Ltd.

Akira Yokota

Kimihiko Nishioka

Susumu Takahashi

Tsutomu Yamamoto

Minoru Okabe

Akira Hasegawa

Takeaki Nakamura

Akira Suzuki

Hiroyuki Fukuda

Hiroki Hibino

Shinichiro Hattori

Takashi Tsukaya

Takao Mori

Koichi Matsui

Nobuo Yamashita

Tatsuya Yamaguchi

Masanao Murata

Iwao Kanamori

Kazunari Kobayashi

Kenji Hirooka

Yoshihito Shimizu

Kenichi Kikuchi

Yoshikazu Tojo

Tomoaki Sato

Katsuyuki Kanehira

Koji Kanbara

Masao Kuga

Masayoshi Naito

Syuichiro Ogasawara

Kikumi Tojo

An objective optical system for endoscopes consisting, in order from the object side, of a front lens unit having a negative refractive power, and a rear lens unit which is composed of a single lens component and has a positive refractive power. This objective optical system comprises a small number of lens components, has favorably corrected aberrations and satisfies the following condition:

Objective optical system for endoscopes

An imaging optical system which is designed so as to be connecatable and disconnectable to and from an image guide, and arranged in a camera control unit. This imaging optical system is arranged between an image guide attached to the camera control unit and an image pickup device accommodated in the camera control unit in a condition integrated with said members, equipped with no eyepiece lens, used exclusively with a monitor TV and designed as a zoom lens system.

Optical device for photographing images formed from optical fiber bundles

An image forming optical system provided with an image forming lens forming an object, as an image, having large spectrum components in a specific spatial frequency on an image receiving device performing discretely spatial sampling and an optical low-pass filter that a response is reduced to zero in the specific spatial frequency or in a frequency in the vicinity thereof, in order to reduce large spatial frequency spectrum components in the image of the object which cause a false signal and moire and to thereby make it possible to photograph and observe a clear object image.

Imaging device and endoscope system provided with the same

An image pickup system using an objective lens system for endoscopes consisting of an objective lens system comprising a front lens unit having negative refractive power and a rear lens unit having positive refractive power, and an optical system comprising an image sensor, and so adapted as to permit disposing the image sensor obliquely or parallel relatively to the optical axis by prolonging back focal length of said objective lens system and arranging an optical path deflecting system between said objective lens system and said image sensor.

Objective lens system for endoscopes and image pickup system equipped

An image pickup system for endoscopes includes an image guide fiber bundle, a light guide fiber bundle, an imaging lens unit having optical low-pass filters, and a solid-state image pickup device. Further, a first optical low-pass filter having a spatial frequency response depending on an array of fibers of the image guide fiber bundle and a second low-pass filter having a spatial frequency response depending on a sampling frequency of the solid-state image pickup device can also be provided between the image guide fiber bundle and the solid-state image pickup device. Thus, even in the image guide fiber bundle which is different in effective diameter and core diameter and has a disorderly array of fibers, the generation of moire can be prevented without reducing resolution.

Image pickup system for an endoscope using a first filter matched to a

An illumination optical system for endoscopes wherein, in order to make it possible to make an illumination of a uniform and sufficient brightness over a wide range of the surface of an object to be observed, a cover lens arranged in front of the exit end face of a light guide is so formed that its surface on the object side may be a convex aspherical surface or may be a convex spherical surface or may have a concave center part and larger in the refractive index in the peripheral part than in the center part. The light guide may be a light emitting device.

Illumination optical system for endoscopes

An endoscope apparatus for inspecting an object including an insertion section insertable into the object and having a distal end and a proximal end, an image guide arranged within the insertion section and having entrance and exit ends arranged at the distal and proximal ends of insertion section, respectively, an objective lens system arranged at the distal end of insertion section for forming an optical image of the object onto the entrance end of image guide, an eyepiece lens system arranged at the proximal end of insertion section for projecting the optical image transmitted through the image guide onto an observating position, a first piezo-electric bimorph arranged at the distal end of insertion section for vibrating the entrance end of image guide in a direction perpendicular to a longitudinal axis of the insertion section over a given distance, a second piezo-electric element arranged at the proximal end of insertion section for vibrating the exit end of image guide in the same direction and over the same distance as those of the entrance end of image guide, so that annoying black mesh and Moire fringe are removed.

Endoscope apparatus

An objective lens system for an endoscope comprising a front lens unit, a stop, and a rear lens unit wherein the front lens unit comprises a lens component arranged that the surface on the object side thereof is formed as an aspherical surface having portions whose curvature is made gradually stronger as they are farther from the optical axis or a lens component arranged that the surface on the image side thereof is formed as an aspherical surface having portions whose curvature is made gradually weaker as they are farther from the optical axis, and the rear lens unit comprises a lens component arranged that the surface on the image side thereof is formed as an aspherical surface having portions whose curvature is made gradually stronger as they are farther from the optical axis or a lens component arranged that the surface on the object side thereof is formed as an aspherical surface having portions whose curvature is made gradually weaker as they are farther from the optical axis, the objective lens system for an endoscope being arranged that distortion and curvature of field are corrected favorably.

Objective lens system for an endoscope

An objective for an endoscope comprising, in the order from the object side, a first lens unit I having negative refractive power, a second lens unit II having positive refractive power, a third lens unit III having positive refractive power, an aperture stop S arranged between the front end of the second lens unit and rear end of the third lens unit and a fourth lens group IV comprising a lens component which has a concave surface on the object side, the four unit objective for an endoscope being arranged so that the overall length is short, outer diameter of the objective is small, angle of view is wide, intensity of light in the marginal portion is high, and distortion is corrected favourably.

Objective for an endoscope

In order to make it possible to observe the image of an object as an erect (correct) image and also to construct the entire device in a compact size, the optical system for altering the direction of the visual field for use in endoscopes comprises visual field direction altering means composed of the combination of a first prism having a light-incidence surface normal to the optical axis of the incident light and a second prism having a light-emitting surface normal to the optical axis of the optical system located rearwardly of the first prism, and arranged so that the vertical angle between the light-incidence surface and the light-emitting surface of the first prism and the vertical angle between the light-incidence surface and the reflection surface of the second prism are structured, respectively, to satisfy certain specific conditions. This visual field direction altering optical system can be constructed as an adapter removably mounted to the foremost end portion of the endoscope.

Optical system for altering the direction of the visual field in

A retrofocus-type objective for an endoscope which comprises a first lens component comprising a negative lens, a stop, a second lens component comprising a positive meniscus lens, a third lens component comprising a positive lens, a fourth lens component comprising a cemented doublet which consists of a positive lens and a negative lens, and a fifth lens component comprising positive lens, the retrofocus-type objective for an endoscope being arranged to be focused by advancing the third and fourth lens components.

Retrofocus-type objective for an endoscope

An optical system is disclosed for an endoscope having a generally tubular distal end in which an objective lens assembly and an image sensor in the form of a solid-state video camera are internally housed so that an image formed by the lens assembly is focussed upon the input or pickup surface of the video camera. The video camera is disposed along or in proximity to the center axis of the distal end of the endoscope and in some instances is oblique with respect to the center axis. The video camera may be positioned in this way due to the provision of a reflecting surface which is angularly disposed in opposing relationship with an input surface of the video camera, and deflection means disposed in front of the lens assembly and within the objective lens assembly, or between the lens assembly and the reflecting surface so that an image formed by the lens assembly can be focussed on the input surface of the video camera.

Optical system for endoscope

An objective lens system for an endoscope comprising a first lens component arranged as a positive meniscus lens, a second lens component arranged as a biconvex lens, a third lens component arranged as a positive cemented doublet, a fourth lens component arranged as a positive cemented doublet, a fifth lens component arranged as a negative cemented doublet, and a sixth lens component arranged as a negative cemented doublet, the objective lens system for an endoscope being arranged that the magnification is high, i.e., 30X to 40X, and aberrations are corrected favorably.

An optical system is disclosed for an endoscope having a generally tubular distal end in which an objective lens assembly and a solid-state video camera are internally housed so that an image formed by the lens assembly is focussed upon the video camera. The video camera is disposed along or in proximity to the center axis of the distal end of the endoscope. The video camera may be positioned in this way due to the provision of a reflecting surface which is angularly disposed in opposing relationship with an input surface of the video camera, and deflection means disposed in front of the lens assembly and within the objective lens assembly, or between the lens assembly and the reflecting surface, so that an image formed by the lens assembly can be focussed on the input surface of the video camera.

An objective lens system for an endoscope comprises a first lens component having a negative refracting power, a second lens component having a positive refracting power, a third lens component having a positive refracting power and a fourth lens component involving a meniscus lens having its concave surface facing the object side, with the lens system being such that the total length is short, the outside diameter is small, the angle of view is wide, and the illuminance in the peripheral portion of the image field is high.

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Sagamihara, Japan

Akira Yokota