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US4486091A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrophotographic copier

Assignee: TIM SpA
•
Filing: 1983-07-25
•
Granted: 1984-12-04
•
Expires: 2003-07-25
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Abstract

Abstract The photocopier uses a development process employing a magnetic brush formed on a rotating sleeve (102) of non-magnetic material in which a system of permanent magnets (108) rotates. The outer surface of the sleeve is subjected to a sandblasting process after grinding in order to create a very uniform finely roughened surface in order to make the thickness of the toner layer forming the magnetic brush constant. The photocopier also employs a toner fixing system operating cold and under pressure by means of a pair of rollers (56, 58) of different diameter rotating at the same angular speed in order to create slippage of the upper roller relative to the lower roller for the purpose of obtaining perfectly flat copies. The copier also contains a single circuit board (80) for the low voltage and high voltage supply.

Inventors

  • 👤 Bruno Cestari
  • 👤 Riccardo Forlani
  • 👤 Piero Gontero

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 19:24
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/80; G03G15/06; G03G15/08; G03G15/09; G03G15/0921; G03G15/0928

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 113 words
Electrophotographic copier comprising means for developing a latent image of an original to be reproduced and formed on a photoconductor element, means for transferring the developed image on to a sheet of paper, and a pair of opposing rollers for the cold-fixing of the image transferred on to said sheet, by the action of the pressure between the rollers, said rollers having their axes inclined to each other and at least one roller having a rough surface, wherein said one roller with the rough surface has a peripheral speed greater than the opposing roller of the pair, so that any deformation of the sheet caused by the inclination of the rollers is nullified.
Claim 2
Dependent Claim 113 words
Electrophotographic copier comprising means for developing a latent image of an original to be reproduced and formed on a photoconductor element, means for transferring the developed image on to a sheet of paper, and a pair of opposing rollers for the cold-fixing of the image transferred on to said sheet, by the action of the pressure between the rollers, said rollers having their axes inclined to each other and at least one roller having a rough surface, wherein said one roller with the rough surface has a peripheral speed greater than the opposing roller of the pair, so that any deformation of the sheet caused by the inclination of the rollers is nullified.
Claim 3
Dependent Claim 30 words
Copier as claimed in claim 1, wherein said rollers rotate at the same angular speed in opposite directions and said rough roller has a greater diameter than the opposing roller.
Claim 4
Dependent Claim 24 words
Copier as claimed in claim 1, wherein the rough roller slips on the opposing roller with a slippage ratio of between 0.001 and 0.003.
Claim 5
Dependent Claim 61 words
Copier as claimed in claim 1, wherein said opposing roller is lubricated with silicone oil by means of a lubricating element formed from a sprongy member enclosed within a fabric provided with pile fibres on its outer face, so that the oil is transferred by contact, to the rough roller in order to prevent toner particles adhering to the surface thereof.
Claim 6
Dependent Claim 25 words
Copier as claimed in claim 4, wherein said fabric is a velvet having a layer of pile fibres of length from 1 to 10 mm.

References Cited (Backward Citations)

US3219014A Cited
US4195927A Cited
DE3014848A1 Cited
US4377332A Cited
US4348098A Cited
US4274361A Cited
US4382673A Cited
US4368971A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-12-04 1988-06-04 1988-12-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-12-04 1992-06-04 1992-12-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-12-04 1996-06-04 1996-12-04 $7700.00 Window Closed / Lapsed

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