US3972600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mirror with adjustable focal distance
Assignee: Braun GmbH
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Filing: 1973-11-12
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Granted: 1976-08-03
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Expires: 1993-11-12
Abstract
Abstract A mirror is provided having an adjustable focal length. The mirror includes a tubular frame in which is mounted a pair of end walls, either one or both of which may be transparent, and an internal, flexible wall that divides the frame member into two separate chambers. Where one transparent end wall is provided, the flexible, internal wall has a single reflecting surface in opposition thereto. Where two transparent end walls are provided, the flexible internal wall has two oppositely facing reflecting surfaces. A conduit provides direct communication between both chambers and a reversible pump is in communication with said conduit for selectively producing controllable pressures in the two chambers.
Inventors
- 👤 Claus Christian Cobarg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:02
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/0816; G02B26/0825
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
136 words
A mirror having an adjustable focal length, said mirror comprising the combination of an elongated, tubular frame member, a first pair of wall members closing the ends of said frame member wherein at least one of said first pair of wall members is transparent, a second, flexible wall positioned within said frame member and having at least one reflecting surface on at least a portion thereof, said reflecting surface portion being in opposition to said transparent one of said first pair of wall members, said second flexible wall dividing said frame member into separate chambers, conduit means communicating directly with both said chambers and a reversible pump in communication with said conduit means whereby the gas volumes in said chambers can be pumped from one to the other for selectively producing controllable pressures in said chambers.
Claim 2
Dependent Claim
136 words
A mirror having an adjustable focal length, said mirror comprising the combination of an elongated, tubular frame member, a first pair of wall members closing the ends of said frame member wherein at least one of said first pair of wall members is transparent, a second, flexible wall positioned within said frame member and having at least one reflecting surface on at least a portion thereof, said reflecting surface portion being in opposition to said transparent one of said first pair of wall members, said second flexible wall dividing said frame member into separate chambers, conduit means communicating directly with both said chambers and a reversible pump in communication with said conduit means whereby the gas volumes in said chambers can be pumped from one to the other for selectively producing controllable pressures in said chambers.
Claim 3
Dependent Claim
16 words
The mirror according to claim 1 wherein both said first pair of wall members are transparent.
Claim 4
Dependent Claim
17 words
The mirror according to claim 2 wherein said second, flexible wall has two oppositely facing reflective surfaces.
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) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |