View finder for single-lens reflex camera

Abstract

Abstract PURPOSE:To shorten a focal distance of an eyepiece system, and also to prevent a drop of the scale factor of a magnifier, by placing composite positive lens component and negative lens component so as to leave a large air gap. CONSTITUTION:A light beam refracted and reflected by a photographing lens and a spring-up mirror which are not shown in the figure forms an image on a focal surface 1a of a focal plate 1, and after that, reaches an eyepiece 10 consisting of a positive lens 5 and a negative lens 6 through a condenser lens 2, a prism 3 and a pentagonal Dachprisma 4, and the image on the focal surface 1a is observed by a naked eye 7 placed on the eyepoint. The prism 4 serves as range finding or photometry, by a half mirror 3a, etc. provided on the inside thereof. The shaded portion of the figure shows an information processing member such as an optical system, an electric system, a hardware member, etc. for range finding or photometry. The positive lens component 5 constituting the eyepiece 10 is a compositive positive glued lens which has glued a biconvex positive lens and a negative lens, and the negative lens component 6 is a single negative lens.

Inventors

• 👤 Yutaka Iizuka

Bibliographic Details