US4326787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetized shutter blades
Assignee: Canon Inc
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Filing: 1981-04-16
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Granted: 1982-04-27
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Expires: 2001-04-16
Abstract
Abstract A camera shutter having a plurality of shutter blades consisting of thin plastic plates operable by means of a comparatively small driving power, so designed that in order to avoid the formation of slits at the overlapped portions of the shutter blades due to deformation magnetic powder is put in the shutter blade and magnetized along the direction of the thickness in such a manner that the blades attract each other by means of magnetic force.
Inventors
- 👤 Michio Senuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:46
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/10; G03B9/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
64 words
In a camera shutter having a plurality of shutter blades which partially overlap each other when an exposure opening in said camera is covered, the improvement comprising that said shutter blades consist of plastic sheets containing magnetic powder and are magnetized along the direction of the thickness thereof in such a manner that each shutter blade attracts the adjacent blade at the overlapped portion.
Claim 2
Dependent Claim
64 words
In a camera shutter having a plurality of shutter blades which partially overlap each other when an exposure opening in said camera is covered, the improvement comprising that said shutter blades consist of plastic sheets containing magnetic powder and are magnetized along the direction of the thickness thereof in such a manner that each shutter blade attracts the adjacent blade at the overlapped portion.
Claim 3
Dependent Claim
52 words
In a camera shutter having a plurality of shutter blades which partially overlap each other when an exposure opening in said camera is covered, the improvement comprising that said shutter blades consist of plastic sheets having both surfaces covered with coatings containing magnetic powder magnetized along the direction of the thickness thereof.
Claim 4
Dependent Claim
52 words
In a camera shutter having a plurality of shutter blades which partially overlap each other when an exposure opening in said camera is covered, the improvement comprising that said shutter blades consist of plastic sheets having both surfaces covered with coatings containing magnetic powder magnetized along the direction of the thickness thereof.
References Cited (Backward Citations)
US4051499A
Cited
US4150890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-26 | 1985-10-26 | 1986-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-26 | 1989-10-26 | 1990-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-26 | 1993-10-26 | 1994-04-27 | $7700.00 | Window Closed / Lapsed |