US 6,473,217 B2 · Diaphragm device

Abstract

The space required in the vicinity of a shutter aperture can be reduced to achieve an overall reduction in size of a device by providing a diaphragm mechanism for covering the shutter aperture formed of a plurality of members cooperating with each other to cover the shutter aperture. By cooperation of a small-diaphragm plate having a diaphragm aperture formed therethrough smaller in diameter than the shutter aperture and an auxiliary plate, for example, a space reduction is facilitated. The small-diaphragm plate is pivotably mounted adjacent one side of the shutter aperture. The auxiliary plate has a shape that cooperates with the convex-arcuate portion to cover the shutter aperture. When the small-diaphragm plate and the auxiliary plate are driven by the diaphragm actuating member and moved to a first position covering the shutter aperture, the two plate cooperate to fully cover the shutter aperture. In a second position retracted from the shutter aperture, the space around the shutter aperture is reduced because the small-diaphragm plate is small in size.

Claims16

Dependent claims

A diaphragm device comprising:

a shutter having a shutter aperture;
a small-diaphragm plate having a diaphragm aperture smaller in diameter than the shutter aperture and movable between a first position at which the diaphragm aperture is positioned within the shutter aperture and a second position at which the diaphragm aperture is not within the shutter aperture;
an auxiliary plate cooperating with the small-diaphragm plate to cover the shutter aperture and being movable between a first position at which the auxiliary plate is positioned within the shutter aperture and a second position at which the auxiliary plate is not within the shutter aperture;
and a diaphragm actuating member for actuating at least one of the small-diaphragm plate and the auxiliary plate;
wherein actuation of the diaphragm actuating member in a first direction causes the small-diaphragm plate and the auxiliary plate to be moved to the first positions to cover the shutter aperture, and actuation of the diaphragm actuating member in a second direction opposite the first direction causes the small-diaphragm plate and the auxiliary plate to be moved to the second positions retracted from the shutter aperture.

2 more elements

Dependencies are inferred from the claim text.

Diaphragm device

Life of this patent

Diaphragm device

Life of this patent

Abstract

Claims16