Exposure control device for photographic cameras

US4054887A · kind A · utility

Assignee

• Ernest Leitz GmbH

Inventors

• Werner Holle · Wetzlar, DE
• Walter Bletz · Solms, DE
• Rolf Magel · Reiskirchen, DE

Key dates

• Filing date: Jul 1, 1976
• Grant date: Oct 18, 1977
• Expiry date: Jul 1, 1996

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B7/085
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Exposure control device for a photographic camera wherein, in a part of the exposure control device, electronic means are provided in order to form, from the luminous density of an object, the film sensitivity, and the preselected time, a voltage analogous to a diaphragm setting, and wherein a storage means is provided for storing this value, the improvement comprising the combination of the following features: A. when the camera release is actuated, the diaphragm begins to operate from an initial position corresponding to the maximum diaphragm opening, a diaphragm path meter coupled therewith operating simultaneously with this diaphragm and yielding a value corresponding to the change in aperture; B. means are provided which compare the value produced by the diaphragm path meter with the stored value and, in case of identical values, or compensation of the values, stop the operation of the diaphragm by a stop member; C. furthermore, means are provided which add the remaining difference value between the formed value and the value formed by the diaphragm path meter to the value corresponding to the preselected time; and D. the open time of the shutter is formed by conventional elec…