US4210387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focus device for zoom lens
Assignee: Pentax Corp
•
Filing: 1979-04-06
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Granted: 1980-07-01
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Expires: 1999-04-06
Abstract
Abstract A focus device for a zoom lens having a mounting barrel focus member and a variator member. A stopper defines a short distance limit stop position. The stopper moves in cooperation with the variator member so that in a particular range of a focal distance of the zoom lens, the short distance photographing limit is advanced to allow extreme close-up photography.
Inventors
- 👤 Ryota Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:22
CPC Classifications
G; G02; G02B; G02B15/00; G02B7/00; G02B7/02; G02B7/04; G02B7/10; G02B7/105
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
82 words
In a focussing device for a zoom lens including a lens mount barrel, a focussing member, a variator member, and a stopper defining a short distance photographing limit for said focussing member, the improvement comprising; means for moving said stopper in cooperation with said variator member, whereby in a particular range of a focal distance of the zoom lens said short distance photographing limit is advanced in the extreme short distance photographing direction to facilitate extreme close-up photographing with said zoom lens.
Claim 2
Dependent Claim
82 words
In a focussing device for a zoom lens including a lens mount barrel, a focussing member, a variator member, and a stopper defining a short distance photographing limit for said focussing member, the improvement comprising; means for moving said stopper in cooperation with said variator member, whereby in a particular range of a focal distance of the zoom lens said short distance photographing limit is advanced in the extreme short distance photographing direction to facilitate extreme close-up photographing with said zoom lens.
Claim 3
Dependent Claim
21 words
A focussing device as defined in claim 1, wherein said means for moving comprises securing said stopper on said variator member.
Claim 4
Dependent Claim
26 words
A focussing device as defined in claim 1, wherein said means for moving comprises securing said stopper on a variator ring rotatably surrounding said variator member.
Claim 5
Dependent Claim
24 words
A focussing device as in claim 3 wherein said variator ring is positioned on said lens mount barrel for rotation with said variator member.
Claim 6
Dependent Claim
53 words
A focussing device as claimed in claims 1, 2 or 3 wherein said focussing member comprises a focus lens, a focus lens mount coaxial with said lens barrel mount and overlapping it to engage said stopper, and a cam surface defining the axial extension of said focus lens mount relative to said stopper.
References Cited (Backward Citations)
DE1169280B
Cited
DE2338097A1
Cited
US3970368A
Cited
DE2364574A1
Cited
US4110005A
Cited
DE2555953A1
Cited
DE2715780A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-01 | 1983-12-31 | 1984-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-01 | 1987-12-31 | 1988-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-01 | 1991-12-31 | 1992-07-01 | $7700.00 | Window Closed / Lapsed |