Photographic diaphragm with two independent sets of leaves

US4199247A · kind A · utility

Assignee

• Carl Zeiss Stiftung · DE

Inventor

• Gerhard Schwarz · Altentreptow, DE

Key dates

• Filing date: Jun 12, 1978
• Grant date: Apr 22, 1980
• Expiry date: Jun 12, 1998

Classification

• Technology area (CPC G): Physics
• CPC primary: G03B9/07
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A photographic diaphragm of the iris type, having two sets or series of diaphragm leaves instead of the usual single set. Each leaf is relatively narrow in a direction radially with respect to the optical axis, thereby reducing the radial dimensions of the annual space necessary to receive the leaves when the diaphragm is fully open. During a closing down movement to a smaller aperture, both sets or series of diaphragm leaves swing inwardly simultaneously during the first part of a closing movement; then one set of leaves remains stationary while the other set continues to swing inwardly to close the aperture down to as small a size as desired. The two series of leaves are in separate planes slightly spaced from each other in the direction of the optical axis. The diaphragm is preferably of the spring back type, which will spring back automatically to a predetermined aperture after it has been opened wide for focusing purposes.