Asahi Kogaku Kogyo Kabushiki Kaisha

Pentax Corporation

Hoya Corporation

Asahi Kogaku Kabushiki Kaisha

Takaaki Yano

Tatsuya Yoshida

Tomoyuki Nishikawa

Tetsuya Abe

Kiyoshi Negishi

Masahiro Kita

Ryoji Honda

Shoji Kamasako

Tsutomu Sato

Sachio Hasushita

Kenichiro Otsuka

Masami Shirai

Masatoshi Takano

Mikio Horie

Kazuhiro Ichinokawa

Masakazu Hirano

Satoshi Hokamura

Eiichi Ito

Motohiro Maseki

Takayuki Ito

Ikuo Negoro

Hidefumi Kaneko

Masahide Inoue

Tsutomi Sato

A relay finder optical system, of a single-lens reflex camera, includes a condenser lens group, a prism, and a relay lens group, in this order from a primary imaging plane. An image, which is formed on the primary imaging plane, and is upside down and inverted from left to right, is re-formed on a secondary imaging plane for viewing by a photographer. The relay lens group includes a positive front lens group, a negative intermediate lens group, and a positive rear lens group, in this order from the object. The most photographers-eye side lens element of the positive rear lens group comprises a positive lens element having a convex surface facing toward the image, and satisfies the following conditions:1&#x3c;SF&#x2003;&#x2003;(1)&#x2212;6&#x3c;&#x3c;&#x2212;3&#x2003;&#x2003;(2)SF: the shaping factor of the most photographers-eye side positive lens element (SF=(rr)/(rr)); r: the radius of curvature of the object-side surface of the most photographers-eye side positive lens element; r: the radius of curvature of the photographers eye-side surface of the most photographers-eye side positive lens element; f: the focal length of the relay finder optical system; and fM: the focallength of the negative intermediate lens group.

Relay finder optical system of an single-lens reflex camera

A light-emitting unit for superimposement is provided. The light-emitting unit is applied to one of a pentagonal roof-mirror or a pentagonal Dach-prism of a viewfinder optical system of a camera. The unit comprises a light source, a light-emitting lens, and a second mirror. The light source emits superimposing light. The second mirror reflects light emitted from the light source and passed through the light-emitting lens toward a third reflection face of one of a pentagonal roof-mirror or a pentagonal Dach-prism. The light source, the light-emitting lens, and the second mirror are integrally assembled as a unit.

Light-emitting unit and superimposing device

Image-blur correcting viewing-optical system

Super wide angle zoom strobe apparatus and zoom compact camera having zoom strobe device

A flash device includes a flash tube; a reflector having a first reflector portion and a second reflector portion which are arranged symmetrically with respect to a plane including an axis of the flash tube, a space between the first reflector portion and the second reflector portion increasing in a direction toward a front end aperture of the reflector; and a lens positioned so as to be opposed to the front end aperture of the reflector. At least a part of the first reflector portion on a side of said front end aperture and at least a part of the second reflector portion on a side of said front end aperture are interlocked with each other to be movable in opposite directions along a direction perpendicular to the plane.

Flash device

A zoom strobe device is provided with a light emitting unit, which includes a light source and a reflector and a light collecting lens that collects the light emitted by the light emitting unit. The light emitting unit and the light collecting lens are movable relative to each other in a direction of an optical axis of the light collecting lens. The light collecting lens is configured such that a light emitting unit side surface has a positive power, and a surface opposite to the light emitting unit side surface (i.e., the object side surface) has a negative power. The light collecting lens has a positive power as a whole.

Zoom strobe device

A viewing optical instrument includes an objective optical system and an eyepiece optical system such that an object image formed through the objective optical system is magnified and observed through the eyepiece optical system. The viewing optical instrument includes an eyepiece adjusting device which allows the eyepiece optical system to rotate relative to the objective optical system about a rotational axis at which an optical axis of the objective optical system intersects a focal plane formed by the objective optical system. A detector detects an inclination of a surface of a sighting object relative to a plane which is normal to the optical axis of the objective optical system, and a controller control the eyepiece optical system to rotate about the rotational axis in accordance with the inclination detected by the detector.

Viewing optical instrument

Disclosed is a dual image coincidence type finder system for a camera. Within a finder field, a dual image composed of superimposed two images is formed. A light deflecting system is provided to change degree of relative displacement between the superimposed two images. The light deflecting system is controlled to change the degree of relative displacement between the superimposed two images in accordance with an object distance.

Dual image coincidence type finder system

Image-blur correcting optical system for a viewing optical apparatus

An optical system for a binocular is provided with an objective optical system, an erecting system and an observing optical system. The objective optical system includes a first lens having positive refractive power, a second lens and a third lens arranged in the order from an object side. At least one lens surface of the first lens is an aspherical surface. One of the second and third lenses has positive refractive power, the other has negative refractive power. The first lens is capable of moving in a direction orthogonal to an optical axis to stabilize an image.

Optical system for observing device having image-vibration compensation system

A variable-power type eyepiece lens system, in a variable-power type observational optical system, comprises, a positive first lens group including a negative meniscus lens element and a bi-convex positive lens element which are cemented together; a second lens group including a single plastic-made bi-convex lens element having at least one aspherical surface; a third lens group including a single plastic-made bi-concave lens element having at least one aspherical surface; wherein an object image by the objective lens system is formed between the second and third lens groups, and when variable power is performed from the long focal length extremity towards the short focal length extremity, the second lens group is moved closer to the first lens group, and the third lens group is moved away from the first lens group, and the following conditions are satisfied: 1.5&lt;.DELTA.LD/M&lt;3.0 . . . (1) 1.8&lt;f2/fS&lt;2.6 . . . (2) wherein M: the magnification ratio of the eyepiece lens system; .DELTA.LD: the change of the overall length of the eyepiece lens system upon variable power being performed; f2: the focal length of the second lens group; and fS: the focal length of the overall system of the eyepiece lens system at the short focal length extremity.

Variable-power type observational optical system and a variable-power

A branch image pickup and view system includes an objective lens system, an image pickup surface which is adapted to pick up an image formed by the objective lens system, an eyepiece lens system through which an image formed by the objective lens system is viewed, an optical separation system provided behind the objective lens system to split light into a light bundle for the image pickup surface and a light bundle for the eyepiece lens system, a condenser lens provided in the optical path from said optical separation system to said optical eyepiece system to relay the image formed through the objective lens system to the eyepiece lens system, and an optical enlargement system which is provided between the optical separation system and the condenser lens.

Branch image pickup and view system

Disclosed is a real image type finder optical system which is provided with an objective optical system having a positive power, an erecting optical system for erecting a reversed real image formed by the objective optical system, an eyepiece optical system for observing the real image formed by the objective optical system and erected by the erecting optical system, an information display element provided in the objective optical system, the information display element displaying information to be observed in a field of view of the finder optical system, and a partial mirror surface provided on an object side with respect to the information display element, the partial mirror allowing a part of light from the object to pass therethrough and reflecting light from the information display element towards the eyepiece optical system.

Real image type finder optical system

An eyepiece optical system includes the first lens group constituted by a negative single meniscus lens element having a convex surface on the side of a user's eye, and the second lens group having positive power as a whole, in this order from the object, whereby an intermediate image formed by an objective optical system is positioned between the first lens group and the second lens group. The second lens group includes a positive single meniscus lens element having a convex surface on the side of a user's eye, and a cemented sub-lens group having positive power as a whole. The cemented sub-lens group includes a positive lens element and a negative lens element. Furthermore, the eyepiece optical system satisfies the following conditions:

Growing community of inventors

Hokkaido, Japan

Takaaki Yano