US 4,394,081 A · Magnetically controlled shutter

Abstract

Disclosed is a magnetically controlled focal plane shutter wherein one electromagnet controls a leading shutter curtain and another electromagnet controls a following shutter curtain by releasing respective checking members as power is supplied thereto. The electromagnetic characteristics of the electromagnet that controls the following shutter curtain differ from those of the electromagnet controlling the leading shutter curtain. According to a specific embodiment disclosed, the follower-curtain controlling electromagnet saturates earlier than the leading curtain controlling magnet so as to compensate for deterioration of an energizing battery and thereby limits the problem of shutter time lag resulting from the long battery use.

Claims8

Dependent claims

A magnetically controlled shutter comprising:

a leading shutter blind and a following shutter blind, a leading checking member for holding the leading shutter blind, a following checking member for holding the following shutter blind, and a leading electromagnet for controlling the leading shutter blind and a following electromagnet for controlling the following shutter blind, each acting on the respective checking members as power is supplied thereto for releasing a checking thereof, the electromagnet for controlling the following shutter blind having magnetic action characteristics different from those of the electromagnet for controlling the leading shutter blind, wherein said electromagnets are attraction type magnets, and wherein said electromagnets have respective yokes made of different magnetic substances.

Dependencies are inferred from the claim text.

Magnetically controlled shutter

Life of this patent

Magnetically controlled shutter

Life of this patent

Abstract

Claims8