Central shutter for cameras, especially professional cameras

US4470679A · kind A · utility

Inventor

• Franz Starp · Greding, DE

Key dates

• Filing date: Feb 3, 1983
• Grant date: Sep 11, 1984
• Expiry date: Feb 3, 2003

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B9/06
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

On professional camera shutters, with an objective comprising a lens system defining an objective light passage, and a polygonal diaphragm, the leaves of which can be actuated by means of a diaphragm actuator control curve cam and in turn be pivoted out of the shutter light passage by means of a steeply ascending cam curve portion, precautions have already been taken to allow adaptation to the given conditions of different shutter objective combinations. These include equipping the diaphragm actuator with an adjusting slide serving to limit the setting range and provided with a scale pointer, and equipping the shutter with a diaphragm scale which is adapted both to the shutter passage size and to the f-number of the objective and which can be attached only when a decision has been made on the combination of the shutter and objective. Since the effect of the steep curve of the diaphragm actuator cam can occur only when the shutter light passage size and the objective light passage correspond to one another, there is assigned to the diaphragm actuator according to the improvement herein a separate curved cam piece which is equipped with an appropriate modifying control curve and whic…