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US4488801A Expired / Lapsed US ⏱️ 0.0 years remaining

Maximum throughput duplexing system for xerographic machines

Assignee: International Business Machines Corp
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Filing: 1983-01-03
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Granted: 1984-12-18
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Expires: 2003-01-03
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Abstract

Abstract First side copying is produced on a sequence of copy sheets equivalent to the number required to fill a closed-loop duplex path that returns the sheets to the imaging station. An identical number of second images are transferred to the opposite sides as they are reintroduced from the closed-loop duplex path through the imaging station. The sheet reintroduction is timed so that the next image transfer cycle is used for the first reintroduced sheet. The copy sheets are passed through a fuser station either prior to exit from the machine or as an element of the closed-loop duplex return path.

Inventors

  • 👤 David K. Gibson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 19:48
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/23; G03G15/231; G03G15/232; G03G15/234

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 199 words
In a xerographic device having a station for transferring an image to copy sheets sequentially fed from an input supply source and a closed-loop copy sheet paper path for returning copy sheets to said image transferring station with the opposite side presented for imaging, and wherein said device is operable to perform regularly spaced image transfer cycles at said station, the process comprising the steps of: feeding M out of N copy sheets sequentially from said source past said image transferring station and into said closed-loop path where N is a whole number corresponding to the maximum number of said copy sheets containable in said closed-loop path and M is a whole number equal to or less than N; transferring a first sequence of M images to a first side of respective said copy sheets during said feeding step; sequentially reintroducing said M out of N copy sheets to said image transferring station from said closed-loop path with the first said reintroduced sheet arriving at said transfer station concurrent with the commencement of the N+1 image transfer cycle; and transferring a second sequence of M images to the opposite side of respective said copy sheets during said reintroducing step.
Claim 2
Dependent Claim 199 words
In a xerographic device having a station for transferring an image to copy sheets sequentially fed from an input supply source and a closed-loop copy sheet paper path for returning copy sheets to said image transferring station with the opposite side presented for imaging, and wherein said device is operable to perform regularly spaced image transfer cycles at said station, the process comprising the steps of: feeding M out of N copy sheets sequentially from said source past said image transferring station and into said closed-loop path where N is a whole number corresponding to the maximum number of said copy sheets containable in said closed-loop path and M is a whole number equal to or less than N; transferring a first sequence of M images to a first side of respective said copy sheets during said feeding step; sequentially reintroducing said M out of N copy sheets to said image transferring station from said closed-loop path with the first said reintroduced sheet arriving at said transfer station concurrent with the commencement of the N+1 image transfer cycle; and transferring a second sequence of M images to the opposite side of respective said copy sheets during said reintroducing step.
Claim 3
Dependent Claim 41 words
The process in accordance with claim 1 which includes the steps of: transferring second side images to the copy sheets during said first sequence transferring steps; and transferring first side images to the copy sheets during said second sequence transferring step.
Claim 4
Dependent Claim 26 words
The process in accordance with claim 2 which includes the step of: delivering the copy sheets to an exit tray after said second sequence transferring step.
Claim 5
Dependent Claim 25 words
The process in accordance with claim 1 which includes the step of fusing the image on each copy sheet after it leaves said transferring station.
Claim 6
Dependent Claim 26 words
The process in accordance with claim 4 which includes the step of delivering the copy sheets to an exit tray after all images are fused thereon.
Claim 7
Dependent Claim 47 words
The process in accordance with claim 1 which includes the steps of: delivering the copy sheets to an exit tray after said second sequence transferring step; and presenting images during said first and second transferring steps for producing sequentially ordered copy sheet sets in said exit tray.

References Cited (Backward Citations)

US4078787A Cited
US4132398A Cited
US4166614A Cited
US4253759A Cited
US4272181A Cited
US4234180A Cited
US4313673A Cited
US4355880A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-12-18 1988-06-18 1988-12-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-12-18 1992-06-18 1992-12-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-12-18 1996-06-18 1996-12-18 $7700.00 Window Closed / Lapsed

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