The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 29, 1985
Filed:
Jul. 21, 1982
Knut Heitmann, Wetzlar, DE;
Klaus-Dieter Schaefer, Braunfels, DE;
Ernst Leitz Wetzlar GmbH, Wetzlar, DE;
Abstract
The exposure meter is used in mirror reflex cameras wherein an image of an object projected by a picture taking lens onto an image plane is observed by means of a pentaprism through an ocular. For the purpose of the selective integral or spot exposure metering, a pentaprism (6) is provided at the lower edge of its exit surface with a partly transmitting concave mirror (16). The angles of the pentaprism (6) are selected so that a portion of the light flux leaving the exit pupil (EP) of the picture-taking lens (2) is incident on this concave mirror (16). A first photoelectric detector system is associated with the concave mirror (16) and a second detector system is associated with the prism surface (6c) following the concave mirror in the direction of the beam path, and the output signals from these detectors control a display and/or an exposure control. An additional optical component (13,14a,15b,15) is provided to implement a desired beam path in the pentaprism (6).