US3844653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Roof mirror copying system
Assignee: Xerox Corp
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Filing: 1973-10-29
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Granted: 1974-10-29
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Expires: 1993-10-29
Abstract
Abstract A duplex copying system in which a roof mirror is alternately positioned for alternate document pages to function as a roof mirror and then as a flat mirror for simplex to duplex copying, and also can pivot between two exposure stations as a flat mirror for duplex to duplex copying. The roof mirror movement can be pivotably coordinated with the movement of a photoreceptor and a copy sheet feeder to provide, with a transfer roller, direct duplex electrostatographic copying. This roof mirror is the only moving mirror required in the system and has two relatively small degrees of rotation.
Inventors
- 👤 D Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:19
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/23; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/522; G03B27/525
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
In optical reproducing apparatus providing duplex copying of an original document onto a single imaging surface, the improvement comprising: an imaging surface; a first exposure station for exposing a side of said original document; an integrally pivotably mounted roof mirror comprising two flat mirror surfaces, said roof mirror being pivotable into a first position in which it is in optical alignment with said first exposure station to provide a first, roof mirror, reflective optical path utilizing both said two flat mirror surfaces, said first reflective optical path extending through said roof mirror from said first exposure station to said imaging surface; and means for pivoting said roof mirror out of said first position into a second position, said roof mirror in said second position having only one of said two flat mirror surfaces in optical alignment with said first exposure station and providing through said one flat mirror surface a second, flat mirror, reflective optical path from said first exposure station to said imaging surface, said second reflective optical path providing, relative to said first reflective optical path, relative reversion on said imaging surface of an image from said first exposure station.
Claim 2
Dependent Claim
192 words
In optical reproducing apparatus providing duplex copying of an original document onto a single imaging surface, the improvement comprising: an imaging surface; a first exposure station for exposing a side of said original document; an integrally pivotably mounted roof mirror comprising two flat mirror surfaces, said roof mirror being pivotable into a first position in which it is in optical alignment with said first exposure station to provide a first, roof mirror, reflective optical path utilizing both said two flat mirror surfaces, said first reflective optical path extending through said roof mirror from said first exposure station to said imaging surface; and means for pivoting said roof mirror out of said first position into a second position, said roof mirror in said second position having only one of said two flat mirror surfaces in optical alignment with said first exposure station and providing through said one flat mirror surface a second, flat mirror, reflective optical path from said first exposure station to said imaging surface, said second reflective optical path providing, relative to said first reflective optical path, relative reversion on said imaging surface of an image from said first exposure station.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 wherein said first and second reflective optical paths are substantially identical in length and wherein there is a common fixed axis lens system therefor.
Claim 4
Dependent Claim
49 words
The apparatus of claim 1 wherein said imaging surface is a moving xerographic photoconductive surface and said means for pivoting said roof mirror are coordinated with the movement of said surface, and wherein copy feed means are provideD for feeding a copy sheet into engagement with said photoconductive surface.
Claim 5
Dependent Claim
35 words
The apparatus of claim 1 wherein said roof mirror is pivotably mounted for rotation about a central axis and said first and second positions of said roof mirror are approximately 45 degrees of rotation apart.
Claim 6
Dependent Claim
35 words
The apparatus of claim 2 wherein said roof mirror is pivotably mounted for rotation about a central axis and said first and second positions of said roof mirror are approximately 45 degrees of rotation apart.
Claim 7
Dependent Claim
82 words
The apparatus of claim 1 further including: a second exposure station for said document spaced from said first exposure station; document reversal means for exposing in said second exposure station the opposite side of a document from said first exposure station; wherein said roof mirror is pivotable into a third position in which it is optically aligned with said second exposure station to provide through said roof mirror a third reflective optical path from said second exposure station to said imaging surface.
Claim 8
Dependent Claim
25 words
The apparatus of claim 6 wherein a fixed plane mirror is positioned in the optical path between said second exposure station and said roof mirror.
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) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |