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US 4,378,150 AGranted
Electromagnetically driven shutter
AssigneeCanon Kabushiki Kaisha
InventorsTeiji Hashimoto, Michio Senuma
Life of this patent
Estimating the term…
Abstract
In an electromagnetically driven focal plane shutter of the type having a trailing screen which moves irrespective as to whether a leading screen is moving, there are provided a detecting member arranged to detect movement of the leading screen and an inhibiting means which inhibits the trailing screen from moving when movement of the leading screen is not detected.
Claims8
An electromagnetically controlled shutter member comprising:
- a base member having an opening defining a photographing optical path;
- a first shutter member adapted to be moved relative to said opening;
- first shutter driving means for driving said first shutter member;
- first electromagnetic means for controlling the travel of said first shutter member relative to said opening;
- a second shutter member arranged to move relative to said opening following a predetermined period of time after operation of said first shutter member, said second shutter member being capable of running independently of said first shutter member without regard to whether the first shutter member moves;
- second shutter driving means for driving said second shutter member;
- second electromagnetic means for controlling the travel of said second shutter member;
- detecting means for detecting actuation of said first shutter driving means to effect movement of said first shutter member;
- and
- prohibiting means arranged to prohibit movement of said second shutter driving means when movement of said first shutter driving means is not detected by said detecting means.
7 more elements
Dependencies are inferred from the claim text.