Light quantity adjusting device and photographing device having the same
First Claim
1. A light quantity adjusting device, comprising:
- a base plate with a ring shape having an exposure aperture at a center thereof,a first light quantity adjusting blade arranged in the exposure aperture,a first drive device for opening and closing the first light quantity adjusting blade, said first drive device having a first magnet rotor with a ring shape, a first exciting coil with a ring shape, and a first guiding member for guiding a magnetic field generated in the first exciting coil to a position facing a magnetic pole formed on a circumference side of the first magnet rotor, said first magnet rotor and said first exciting coil being arranged on an inner circumferential edge of the exposure aperture in a stacked state,a second light quantity adjusting blade arranged in the exposure aperture, anda second drive device for opening and closing the second light quantity adjusting blade, said second drive device having a second magnet rotor, a second exciting coil, and a second guiding member for guiding a magnetic field generated in the second exciting coil to a position facing a magnetic pole formed on a circumference side of the second magnet rotor, said second magnet rotor and said second exciting coil being arranged on a portion of an outer circumferential edge of the exposure aperture.
1 Assignment
0 Petitions
Accused Products
Abstract
A light quantity adjusting device includes a ring-shaped base plate having an exposure aperture at a center thereof, a first light quantity adjusting blade arranged in the exposure aperture, a first drive device for opening/closing the first light quantity adjusting blade, a second light quantity adjusting blade arranged in the exposure aperture, and a second drive device for opening/closing the second light quantity adjusting blade. The first drive device includes a magnet rotor and an exciting coil formed in a ring shape, and a guiding member for inducing a magnetic field to a position facing a magnetic pole formed on a circumference side of the magnet rotor. The second drive device includes a magnet rotor, an exciting coil, and a guiding member for guiding a magnetic field to a position facing a magnetic pole formed on a circumference side of the magnet rotor.
5 Citations
9 Claims
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1. A light quantity adjusting device, comprising:
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a base plate with a ring shape having an exposure aperture at a center thereof, a first light quantity adjusting blade arranged in the exposure aperture, a first drive device for opening and closing the first light quantity adjusting blade, said first drive device having a first magnet rotor with a ring shape, a first exciting coil with a ring shape, and a first guiding member for guiding a magnetic field generated in the first exciting coil to a position facing a magnetic pole formed on a circumference side of the first magnet rotor, said first magnet rotor and said first exciting coil being arranged on an inner circumferential edge of the exposure aperture in a stacked state, a second light quantity adjusting blade arranged in the exposure aperture, and a second drive device for opening and closing the second light quantity adjusting blade, said second drive device having a second magnet rotor, a second exciting coil, and a second guiding member for guiding a magnetic field generated in the second exciting coil to a position facing a magnetic pole formed on a circumference side of the second magnet rotor, said second magnet rotor and said second exciting coil being arranged on a portion of an outer circumferential edge of the exposure aperture. - View Dependent Claims (2, 3)
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4. A light quantity adjusting device, comprising:
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a base plate with a ring shape having an exposure aperture at a center thereof, a first light quantity adjusting blade arranged in the exposure aperture, a first drive device for opening and closing the first light quantity adjusting blade, said first drive device having a first magnet rotor with a ring shape and a first exciting coil with a ring shape, a second light quantity adjusting blade arranged in the exposure aperture, and a second drive device for opening and closing the second light quantity adjusting blade, said second drive device having a second magnet rotor with a ring shape arranged on a portion of an outer circumferential edge of the exposure aperture and a second exciting coil with a ring shape having a diameter substantially equal to that of the second magnet rotor, one of said first drive device and said second drive device being arranged on the base plate in a stacked state in an order of the first or second magnet rotor and the exciting coil corresponding thereto, and the other of said first drive device and said second drive device being arranged on the base plate in a stacked state in an order of the first or second exciting coil and the magnet rotor corresponding thereto. - View Dependent Claims (5, 6, 7, 8, 9)
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Specification