JPS5948526U

JPS5948526U - TTL file finder

Info

Publication number: JPS5948526U
Application number: JP14530182U
Authority: JP
Inventors: 石山　唱蔵
Original assignee: コニカ株式会社
Priority date: 1982-09-25
Filing date: 1982-09-25
Publication date: 1984-03-31

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図はズームレンズを用いた従来カメラ゛のファイン
ダ光学系、第２図は従来のシャッタカメラに用いられる
逆ガリレオフアインダ光学系、第３図は本発明の実施例
を示す光学系で第３図ａ及び第３図すは同一実施例につ
き互に直角方向の断面図を示す。３０１．３０２，３０３，３０４・・・・・・部分まで
のレンズ系、３０５・・・・・・光束分割器■、３０８
・・・・・・光束分割器■、３０９・・・・・・凹レン
ズ、３１０・・・・・・凸レンズ、３１１・・・・・・
ミラー、′３１２・・・・・・瞳位置。Fig. 1 shows a finder optical system of a conventional camera using a zoom lens, Fig. 2 shows a reverse Galilean off-finder optical system used in a conventional shutter camera, and Fig. 3 shows an optical system showing an embodiment of the present invention. Figures 3a and 3a show mutually orthogonal cross-sectional views of the same embodiment. 301. 302, 303, 304...Lens system up to part, 305... Luminous flux splitter ■, 308
......Light flux splitter ■, 309...Concave lens, 310...Convex lens, 311...
Mirror, '312...pupil position.

Claims

[Scope of utility model registration request]

In an optical device that uses a zoom lens as a photographing optical system, which has a portion where a light beam from an axial direction becomes almost afocal, a light beam from an axial object is directed to the afocal portion along the optical axis up to the afocal portion of the zoom lens. A light beam splitter 1 that splits the light beam in the vertical direction is provided, a part of the incident light beam is bent by the light beam splitter 1, and a lens system after the afocal portion of the zoom lens is provided in the light beam to form a photographing system, A concave lens is provided in the light beam passing through the light beam splitter 1 in the same direction as the optical axis up to the afocal part of the zoom lens, and a lens system up to the afocal part of the zoom lens and the concave lens are provided. A composite lens system with the above is used as an objective lens, at least one convex lens is provided behind the concave lens, and the convex lens is used as an eyepiece, and up to the afocal part of the zoom lens, a light beam with an F number brighter than the F number required for photography is produced. The diameter of the lens is made large so that the light beam with an F number brighter than the F number required for photography passes through the outside of the semi-transparent part of the light beam splitter 1, and the light beam with the F number brighter than the F number required for photography is made to pass through the outside of the semi-transparent part of the light beam splitter 1. A mirror is provided between the light flux splitter 1, the concave lens, and the mirror, which bends the light flux passing outside the semi-transparent part so as to be perpendicular to the optical axis up to the afocal part of the zoom lens. A beam splitter 2 is provided that bends a part of the beam from the mirror in the same direction as the optical axis up to the afocal portion of the zoom lens, and an image of the beam passing through the semi-transparent portion of the beam splitter 1 and the semi-transparent portion are provided. The lens is characterized in that one surface of the concave lens is made into a half mirror or a part thereof is a mirror, and one surface of the convex lens is formed with a frame. A reverse Galileo-Albada type TTL finder that allows for precise focusing.