Patent DE340300C successfully refreshed from Google Patents.
US4294532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutter blade device for focal plane shutter
Assignee: Seiko Koki KK
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Filing: 1980-04-23
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Granted: 1981-10-13
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Expires: 2000-04-23
Abstract
Abstract In a focal plane shutter for a single lens reflex camera having, on the side of the shutter aperture, two blade groups each consisting of a plurality of separate blades adapted to operate sequentially in exposure operation, a shutter blade device includes said two blade groups having at least some of blades formed of thin synthetic resin plates. A shielding member is provided between a reflex mirror and said blade groups and adapted to retract from an aperture shielding position during the exposure operation of said two blade groups and return to an aperture shielding position before and after the exposure operation.
Inventors
- 👤 Tadashi Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:37
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G03B9/10; G03B9/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
120 words
In a focal plane shutter for a single lens reflex camera having on the side of the shutter aperture two blade groups each consisting of a plurality of separate blades adapted to operate sequentially in exposure operation and located adjacent to the focal plane, a shutter blade device for the focal plane shutter including said two blade groups having at least some of blades formed of thin synthetic resin plates, and a reflex mirror, and characterized by a shielding member provided between the reflex mirror and said blade groups and adapted to retract from an aperture shielding position during the exposure operation of said two blade groups and return to an aperture shielding position before and after the exposure operation.
Claim 2
Dependent Claim
120 words
In a focal plane shutter for a single lens reflex camera having on the side of the shutter aperture two blade groups each consisting of a plurality of separate blades adapted to operate sequentially in exposure operation and located adjacent to the focal plane, a shutter blade device for the focal plane shutter including said two blade groups having at least some of blades formed of thin synthetic resin plates, and a reflex mirror, and characterized by a shielding member provided between the reflex mirror and said blade groups and adapted to retract from an aperture shielding position during the exposure operation of said two blade groups and return to an aperture shielding position before and after the exposure operation.
Claim 3
Dependent Claim
24 words
A shutter blade device as set forth in claim 1 wherein said shielding member is formed of a plurality of flame retardative thin plates.
Claim 4
Dependent Claim
27 words
A shutter blade device as set forth in claim 1 wherein said shielding member is disposed adjacent to the reflex mirror of a single lens reflex camera.
Claim 5
Dependent Claim
44 words
A shutter blade device as set forth in claim 3 wherein said shielding member remains inoperative during the manual operation of said reflex mirror and retracts from the aperture shielding position, together with said reflex mirror, prior to the start of the shutter operation.
Claim 6
Dependent Claim
92 words
In a single lens reflex camera: means for defining a shutter aperture; a movable reflex mirror; a focal plane shutter comprised of a plurality of movable thin synthetic resin blades for opening and for closing the shutter aperture; and shielding means positioned between said reflex mirror and said focal plane shutter for shielding said focal plane shutter from focused light and for retracting from the position effective to shield said focal plane shutter during exposure and for returning to the position effective to shield said focal plane shutter upon completion of exposure.
Claim 7
Dependent Claim
92 words
In a single lens reflex camera: means for defining a shutter aperture; a movable reflex mirror; a focal plane shutter comprised of a plurality of movable thin synthetic resin blades for opening and for closing the shutter aperture; and shielding means positioned between said reflex mirror and said focal plane shutter for shielding said focal plane shutter from focused light and for retracting from the position effective to shield said focal plane shutter during exposure and for returning to the position effective to shield said focal plane shutter upon completion of exposure.
Claim 8
Dependent Claim
19 words
In a single lens reflex camera according to claim 5, said shielding means comprising movable thermally resistant thin plates.
Claim 9
Dependent Claim
18 words
In a single lens reflex camera according to claim 5, said shielding means positioned adjacent said reflex mirror.
Claim 10
Dependent Claim
28 words
In a single lens reflex camera according to claim 7, wherein said shielding means retracts from the shielding position together with said reflex mirror prior to shutter opening.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |