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US3947113A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrophotographic toner transfer apparatus

Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1975-01-20
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Granted: 1976-03-30
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Expires: 1995-01-20
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Abstract

Abstract An improved apparatus is disclosed for transferring toner from the surface of a toner-bearing drum, such as a xerographic drum, to a support medium for the toner, such as plain paper. The improvement relates to apparatus of the type which employs a transfer web or belt to remove toner from the toner-bearing drum and to transfer it to a support medium. In such apparatus, it is typical for the transfer web to be at least partially driven by means of its contact with the toner-bearing drum and/or transfer rollers. The improvement described herein comprises providing means for simultaneously disengaging the toner-bearing drum and at least one of the transfer rollers from the transfer web at least once per web cycle, and also providing means for mechanically correcting web alignment and registration while the toner-bearing drum and transfer roller are disengaged. Suitable means for disengaging the toner-bearing drum and transfer roller include the provision of indented surfaces on the drum and transfer roller. Suitable means for mechanically correcting web alignment and registration includes an independent driving means, such as a chain drive, for the transfer web. Thus, in this embodiment, the indented portions of the toner-bearing drum and transfer roller simultaneously disengage the web which is forced back into proper alignment and registration by the chain drive.

Inventors

  • 👤 William Raymond Buchan
  • 👤 James A. Kulpan
  • 👤 Edward Francis Mayer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 19:30
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/1605; G03G15/1615

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 117 words
In an electrophotographic transfer apparatus wherein toner is transferred from the surface of a toner-bearing drum to a transfer web by pressure contact at a nip therebetween and subsequently transferred from the web to a support medium by feeding said support medium and said transfer web through a nip formed between transfer rollers, and wherein the transfer web is at least partially driven by means of the toner-bearing drum and transfer rollers, the improvement comprising providing: means for simultaneously disengaging the nips at both said toner-bearing drum and at said transfer rollers from said transfer web at least once per web cycle; and, means for mechanically correcting transfer web alignment and registration while said nips are disengaged.
Claim 2
Dependent Claim 117 words
In an electrophotographic transfer apparatus wherein toner is transferred from the surface of a toner-bearing drum to a transfer web by pressure contact at a nip therebetween and subsequently transferred from the web to a support medium by feeding said support medium and said transfer web through a nip formed between transfer rollers, and wherein the transfer web is at least partially driven by means of the toner-bearing drum and transfer rollers, the improvement comprising providing: means for simultaneously disengaging the nips at both said toner-bearing drum and at said transfer rollers from said transfer web at least once per web cycle; and, means for mechanically correcting transfer web alignment and registration while said nips are disengaged.
Claim 3
Dependent Claim 25 words
An electrophotographic apparatus of claim 1 wherein said means for mechanically correcting transfer web alignment and registration comprise independent means for driving said transfer web.
Claim 4
Dependent Claim 18 words
An electrophotographic transfer apparatus of claim 2 wherein said toner-bearing drum comprises a drum having a photoconductive surface.
Claim 5
Dependent Claim 21 words
An electrophotographic transfer apparatus of claim 3 wherein said means for simultaneously disengaging includes an indented surface on said photoconductive drum.
Claim 6
Dependent Claim 21 words
An electrophotographic transfer apparatus of claim 4 wherein said means for simultaneously disengaging includes a transfer roller having an indented surface.
Claim 7
Dependent Claim 48 words
An electrophotographic transfer apparatus of claim 5 wherein said transfer web has a plurality of segments fastened by joints to said independent means for driving the transfer web, and said joints are synchronized to meet the indentations on the photoconductive drum and transfer roller during each web cycle.
Claim 8
Dependent Claim 17 words
An electrophotographic transfer apparatus of claim 6 wherein said independent means for driving comprises a chain drive.
Claim 9
Dependent Claim 15 words
An electrophotographic transfer apparatus of claim 7 wherein said transfer web has an elastomeric surface.
Claim 10
Dependent Claim 36 words
An electrophotographic transfer apparatus of claim 7 wherein said transfer web has a smooth, elastomeric surface with a surface free energy of below about 40 dynes/cm., and a hardness of from about 3 to 70 durometers.
Claim 11
Dependent Claim 16 words
An electrophotographic transfer apparatus of claim 9 wherein said transfer belt is divided into two segments.
Claim 12
Dependent Claim 25 words
An electrophotographic transfer apparatus of claim 10 wherein each of the belt segments has a length substantially equal to the periphery of the photoconductive drum.
Claim 13
Dependent Claim 95 words
In an electrophotographic transfer apparatus wherein toner is transferred from the surface of a toner-bearing member to a transfer web by pressure contact at a first roller nip and subsequently transferred from the web to a support medium by feeding said support medium and said transfer web through a second roller nip, the improvement comprising: a. means for disengaging at least one of said nips from time to time during the operation of said transfer apparatus; and b. means for automatically adjusting transfer web positioning during the disengagement of at least one of said nips.
Claim 14
Dependent Claim 95 words
In an electrophotographic transfer apparatus wherein toner is transferred from the surface of a toner-bearing member to a transfer web by pressure contact at a first roller nip and subsequently transferred from the web to a support medium by feeding said support medium and said transfer web through a second roller nip, the improvement comprising: a. means for disengaging at least one of said nips from time to time during the operation of said transfer apparatus; and b. means for automatically adjusting transfer web positioning during the disengagement of at least one of said nips.
Claim 15
Dependent Claim 64 words
The apparatus as set forth in claim 12 wherein said means for automatically adjusting transfer web positioning comprises a web driving means and wherein one web portion is coupled to said web driving means via a first coupler and another web portion is coupled to said driving device via a second coupler, and wherein at least one of said couplers includes a spring member.
Claim 16
Dependent Claim 19 words
The apparatus as set forth in claim 13 further including means for simultaneously disengaging said first and second nips.
Claim 17
Dependent Claim 21 words
The transfer apparatus of claim 12 wherein said means for disengaging at least one of said nips includes an indented roller.
Claim 18
Dependent Claim 21 words
The transfer apparatus of claim 13 wherein said means for disengaging at least one of said nips includes an indented roller.

References Cited (Backward Citations)

US2990278A Cited
US3591276A Cited
US3792924A Cited
US3893761A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-03-30 1979-09-29 1980-03-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-03-30 1983-09-29 1984-03-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-03-30 1987-09-29 1988-03-30 $7700.00 Window Closed / Lapsed

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