US3834805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Xerographic copier with asynchronous copy feed
Assignee: Unisys Corp
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Filing: 1973-01-29
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Granted: 1974-09-10
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Expires: 1993-01-29
Abstract
Abstract A xerographic copier is provided with a continuously rotating photoconductive drum surface, continuously operative document feed means capable of moving a document through a scanning station in either a forward or reverse direction so that multiple scans of the document may take place when multiple copies are to be made, and copy paper transport means which is normally at rest but is brought into motion during each copy cycle. The copy paper transport moves as the same linear speed as the drum surface so that a toner image on the drum may be transferred to the copy paper. However, since all document images are not placed on the drum at the same area, the time at which the copy paper transport begins moving is not synchronized with any particular point in the drum cycle but is instead synchronized with the document image formed on the drum surface. The original document actuates switches which in turn control the time at which the copy paper transport begins its movement. Since document movement is synchronized with drum surface movement, this provides synchronization between the copy paper feed and the image on the drum.
Inventors
- 👤 B Griffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:51
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/28; G03G15/30; Y; Y10; Y10S; Y10S271/00; Y10S271/902
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
338 words
In a xerographic copier of the type wherein a document is scanned to lay down an electrostatic image of the document on the surface of a rotating xerographic drum, the electrostatic image is developed to produce a visible image adhering to said drum surface, and said drum surface is rotated past a transfer station at which the visible image is transferred to a copy sheet, the improvement comprising: power drive means connected to continously rotate said xerographic drum so that said surface moves at a predetermined speed; document feed roll Means for feeding a document through said scanning station; means responsive to said power drive means for driving said document feed roll means, said means responsive to said power drive means for driving said document feed roll means including forward feed clutch means for connecting said power drive means to rotate said feed roll means in one direction to feed said document in a forward direction in said scanning station, and, reverse feed clutch means for connecting said power drive means to rotate said feed roll means in a second direction to feed said document in a reverse direction in said scanning station; sensing means for sensing when a document being fed through said scanning station in a first direction has reached a first position; a support for supporting a stack of copy sheets; copy sheet transport means for transporting copy sheets one at a time from said stack and past said transfer station at said predetermined speed; a copy sheet transport clutch means for connecting said power drive means to said copy sheet transport means; means reponsive to said sensing means for energizing said copy sheet transport clutch means at a time such that each copy is transported through said transfer station in registration with a visible image; and, means for repetitively and alternately energizing said forward and said reverse feed clutch means whereby a document is repetitively fed through said scanning station and multiple electrostatic images of said document are laid down on said drum surface.
Claim 2
Dependent Claim
338 words
In a xerographic copier of the type wherein a document is scanned to lay down an electrostatic image of the document on the surface of a rotating xerographic drum, the electrostatic image is developed to produce a visible image adhering to said drum surface, and said drum surface is rotated past a transfer station at which the visible image is transferred to a copy sheet, the improvement comprising: power drive means connected to continously rotate said xerographic drum so that said surface moves at a predetermined speed; document feed roll Means for feeding a document through said scanning station; means responsive to said power drive means for driving said document feed roll means, said means responsive to said power drive means for driving said document feed roll means including forward feed clutch means for connecting said power drive means to rotate said feed roll means in one direction to feed said document in a forward direction in said scanning station, and, reverse feed clutch means for connecting said power drive means to rotate said feed roll means in a second direction to feed said document in a reverse direction in said scanning station; sensing means for sensing when a document being fed through said scanning station in a first direction has reached a first position; a support for supporting a stack of copy sheets; copy sheet transport means for transporting copy sheets one at a time from said stack and past said transfer station at said predetermined speed; a copy sheet transport clutch means for connecting said power drive means to said copy sheet transport means; means reponsive to said sensing means for energizing said copy sheet transport clutch means at a time such that each copy is transported through said transfer station in registration with a visible image; and, means for repetitively and alternately energizing said forward and said reverse feed clutch means whereby a document is repetitively fed through said scanning station and multiple electrostatic images of said document are laid down on said drum surface.
Claim 3
Dependent Claim
56 words
The improvement as claimed in claim 1 wherein the means responsive to said sensing means includes: timing cam means; timing cam control clutch means responsive to said sensing means for connecting said power drive means to said timing cam means; and, switch means actuated by said timing cam means for energizing said copy sheet transport clutch.
Claim 4
Dependent Claim
156 words
The improvement as claimed in claim 1 wherein the means for repetitively and alternately energizing said forward and said reverse feed clutch means comprises: second sensing means for sensing when a document being fed through said scanning station has reached a second position; multiple copy cam means including means for manually rotating said multiple copy cam means from a single copy position to a desired multiple copy position; multiple copy motor means for dirving said multiple copy cam means toward said single copy position; timing cam means; timing cam control clutch means responsive to said sensing means for connecting said power drive means to said timing cam means; switch means actuated by said timing cam means for energizing said multiple copy motor means; further switch means actuated by said multiple copy cam means; and, circuit means responsive said switch means and said further switch means for alternately energizing said forward or said reverse feed clutch means.
Claim 5
Dependent Claim
65 words
The improvement as claimed in claim 2 wherein said copy sheet transport means comprises: sheet grippers for gripping an edge of a copy sheet; first and second chain means for supporting and transporting said sheet grippers; gear means, driven when said copy sheet transport clutch is energized, for driving said chains; and, means for delivering copy sheets one at a time to said sheet grippers.
Claim 6
Dependent Claim
73 words
The improvement as claimed in claim 4 wherein said means for delivering copy sheets to said sheet grippers comprises: copy sheet feed roll means; bias means normally biasing said support whereby one sheet of said stack of copy sheets frictionally engages said copy sheet feed roll means; and, means driven by said timing cam means for rotating said copy sheet feed roll means to thereby drive said one sheet into said sheet grippers.
Claim 7
Dependent Claim
53 words
The improvement as claimed in claim 5 and further comprising: an exit station including continuously rotating feed rolls for accepting a copy sheet transported by said shEet grippers; and, fuser means disposed adjacent the path of said sheet grippers, between said transfer and exit stations, for fusing transferred visible images onto copy sheets.
Claim 8
Dependent Claim
107 words
The improvement as claimed in claim 1 and further comprising: lamps for illuminating said document as it passes through said scanning station; means projecting an image of said document onto said drum as said document is scanned to thereby lay down said electrostatic image; cascade developing means for cascading a developer material over said drum after said electrostatic image is laid down to thereby develop said visible image; further sensing means for sensing the presence of a document in said scanning station at a point before it is scanned; and, means responsive to said further sensing means for illuminating said lamps and driving said cascade developing means.
Claim 9
Dependent Claim
206 words
In a xerographic copier of the type wherein a document is scanned to lay down an electrostatic image of the document on the surface of a rotating xerographic drum, the electrostatic image is developed to produce a visible image adhering to said drum surface, and said drum surface is rotated past a transfer station at which the visible image is transferred to a copy sheet, the improvement comprising: power drive means connected to continuously rotate said xerographic drum so that said surface moves at a predetermined speed; document feed means for moving a document through said scanning station in a forward direction at said predetermined speed; copy sheet transport means for transporting copy sheets through said transfer station at said predetermined speed; document feed clutch means for selectively connecting said power drive means to said document feed means so that it may selectively move a document through said scanning station; a copy sheet transport clutch for selectively connecting said drive power means to said copy sheet transport means; document sensing means for sensing the presence of a document at a predetermined position in said scanning station; and, means responsive to said sensing means for selectively energizing said document feed clutch and said copy sheet transport clutch.
Claim 10
Dependent Claim
206 words
In a xerographic copier of the type wherein a document is scanned to lay down an electrostatic image of the document on the surface of a rotating xerographic drum, the electrostatic image is developed to produce a visible image adhering to said drum surface, and said drum surface is rotated past a transfer station at which the visible image is transferred to a copy sheet, the improvement comprising: power drive means connected to continuously rotate said xerographic drum so that said surface moves at a predetermined speed; document feed means for moving a document through said scanning station in a forward direction at said predetermined speed; copy sheet transport means for transporting copy sheets through said transfer station at said predetermined speed; document feed clutch means for selectively connecting said power drive means to said document feed means so that it may selectively move a document through said scanning station; a copy sheet transport clutch for selectively connecting said drive power means to said copy sheet transport means; document sensing means for sensing the presence of a document at a predetermined position in said scanning station; and, means responsive to said sensing means for selectively energizing said document feed clutch and said copy sheet transport clutch.
Claim 11
Dependent Claim
34 words
The improvement as claimed in claim 8 and further comprising: means holding a stack of copy sheets, said copy sheet transport means including means for transporting one sheet at a time from said stack.
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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |