US3584195A - Heat fixing apparatus - Google Patents

Heat fixing apparatus Download PDF

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Publication number
US3584195A
US3584195A US851826A US3584195DA US3584195A US 3584195 A US3584195 A US 3584195A US 851826 A US851826 A US 851826A US 3584195D A US3584195D A US 3584195DA US 3584195 A US3584195 A US 3584195A
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US
United States
Prior art keywords
support material
heat
belt
image
belt member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US851826A
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English (en)
Inventor
Michael A Vince
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xerox Corp
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Xerox Corp
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Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Application granted granted Critical
Publication of US3584195A publication Critical patent/US3584195A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
    • G03G15/2003—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat
    • G03G15/2014—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat

Definitions

  • the apparatus includes a fuser member in the form of an endless belt in contact with the support material being transported.
  • the fusing belt member comprises a highly thermally conductive material which is coated with an electrically insulating material.
  • the support material is electrostatically tacked to the belt member to enhance uniform thermal contact therebetween.
  • image offset is normally a problem in the absence of special offset materials, such as, oil which must be continuously applied to the roller surfaces.
  • special offset materials such as, oil which must be continuously applied to the roller surfaces.
  • heat fixing devices not particularly suited for high-speed copying/duplicating, such as, coiled radiant element heaters with reflectors.
  • These radiant element heaters with reflectors and other types such as the recirculating heated air type have the disadvantage of dissipating a large quantity of heat into the imageenclosure in which they are used, heat transfer to the powder image is inefficient, and for the case of the coiled heater element they present a safety hazard because of the exposed element.
  • thermoplastic particles are to be fixed into and out of contact with heat fusing apparatus without image offset.
  • a direct contact fusing device in which the toner image is fused by forwarding the sheet of support material bearing toner images upon a fuser member in the form of a highly thermally conductive belt which is sufficiently heated to fix the image upon the support material.
  • a corona discharge device is arranged to spray a charge onto the sheet to provide uniform thermal contact between the sheet and belt which is coated with an electrically insulating material to obtain a high quality fix.
  • FIG. 1 illustrates schematically a xerographic reproducing apparatus adapted for high-speed automatic operation and incorporating a heat fuser constructed in accordance with the invention
  • FIG. 2 is an isometric view of the fuser apparatus of the invention.
  • FIG. 1 For a general understanding of the illustrated copier/reproduction machine, in which the invention may be incorporated, reference is had to FIG. 1 in which the various system components for the machine are schematically illus trated.
  • electrostatic systems such as a xerographic machine of the type illustrated
  • a light image of a document to be reproduced is projected onto the sensitized surface of a xerographic plate to form an electrostatic latent image thereon.
  • the latent image is developed with an oppositely charged developing material to form a xerographic powder image, corresponding to the latent image on the plate surface.
  • the powder image is then electrostatically transferred to a support surface to which it is fixed by a fusing device whereby the powder image is caused permanently to adhere to the support surface.
  • an original D to be copied is placed upon a transparent support platen P fixedly arranged in an optical system generally indicated by the reference numeral 10.
  • the image rays are projected by means of the optical system for exposing the photosensitive surface of a xerographic plate in the form of a drum generally indicated by the reference numeral 11.
  • the xerographic drum 11 is mounted upon the frame of the machine and is adapted to rotate in the direction of the arrow at a constant rate.
  • the light image of the original on the platen is projected upon the xerographic surface of the drum at an exposure station A.
  • the exposure of the drum surface to the light image discharges the photosensitive surface in the areas struck by light, whereby there remains on the belt a latent electrostatic image in image configuration corresponding to the light image projected from the original on the supporting platen.
  • the electrostatic image passes through a developing station B in which there is positioned a developer assembly generally indicated by the reference numeral 14.
  • the developer assembly 14 deposits developing material onto the drum whereat the material is directed to cascade down over the drum surface in order to provide development of the electrostatic image. As the developing material is cascaded over the xerographic surface, toner particles in the development material are deposited on the drum surface to form powder images.
  • the developed electrostatic image is transported by the drum surface to a transfer station C whereat a sheet of copy paper is moved at a speed in synchronism with the moving drum in order to accomplish transfer of the developed image.
  • a sheet transport mechanism generally indicated at 16 adapted to transport sheets of paper from a paper handling mechanism generally indicated by the reference numeral 18 to the developed image the drum at the station C.
  • the sheet After the sheet is stripped from the drum, it is conveyed to a fuser apparatus according to the present invention generally indicated by the reference numeral 20 whereat the developed transferred xerographic powder image on the sheet material is permanently affixed thereto as will be described hereinafter. After fusing, the finished copy is discharged from the apparatus by a conveyor 21 to a suitable point for collection externally of the apparatus.
  • Suitable drive means may be arranged to drive the drum in conjunction with exposure of an original to be copied, to effect conveying and cascade of toner material, to separate and feed sheets of paper and to transport the same across the transfer station C and to convey the sheet of paper through the fuser apparatus in timed sequence to produce copies of the original.
  • the fuser apparatus 20 is of the heated type through which a sheet of support material, indicated by the reference letter S, is adapted to be conveyed during a fusing operation.
  • the support material S is conveyed through an entrance slot 22 formed on one side of the housing of fuser apparatus and out of an exit slot 23 formed in an opposite wall of the housing.
  • the housing for the apparatus comprises insulated walls 24 made of a highly reflective material coated with a high thermal insulating material.
  • Within the housing the support material is conveyed by an endless belt 25 supported for movement on and by a pair of rollers 26 and 27 arranged with their axes in parallel.
  • Shafts for the rollers 26 and 27 may be suitably joumaled and connected by driving devices such as timing belts or chains to a suitable drive system to effect continuous movement of the belt in a direction indicated by the arrow to thereby effect movement of the support material through the housing of the fuser apparatus.
  • driving devices such as timing belts or chains to a suitable drive system to effect continuous movement of the belt in a direction indicated by the arrow to thereby effect movement of the support material through the housing of the fuser apparatus.
  • a heater element 30 Located between the upper and lower runs of the belt 25 is a heater element 30 which is in the form of a strip or resistance heater element directed to radiate heat to the belt 25.
  • belt 25 is, in effect, a fusing member adapted to give up heat uniformly to the support material S which carries the toner particles in image configuration.
  • the support material is electrostatically tacked to the belt surface by a corona discharge device 40 connected to a variable power source 41.
  • Power source 41 is variable to enable optimum operation during changes in ambient conditions such as humidity, temperature, etc.
  • the belt surface is coated with a very thin layer of electrically insulating material such as Teflon which also serves to prevent the sheet material from sticking to the belt.
  • Teflon coating should be thin enough so that it does not interfere with the heat conduction through the belt and may range from about 0.002 to about 0.004 inch.
  • the support material will separate from the belt due to its natural stiffness.
  • separating fingers 43 made of suitable material are used to facilitate separation of the sheet material from belt 25.
  • Belt 25 comprises a highly thermally conductive sheet made of material, such as, copper which possesses some resiliency while exhibiting tensile strength of a sufficient magnitude to permit its use as a conveying member.
  • the belt should be relatively thin, for example, approximately from about 0.010 inch to about 0.030 inch so that heat can be conducted through the belt with the heater element on the opposite side from the support material.
  • Each of the rollers 26, 27 are preferably made of heat resistant, heat insulating material and are secured to their respective supporting shafts by way of insulating caps or supports.
  • the distance between the supporting rollers 26, 27 and the length of the belt 25 may be chosen in accordance with necessary or desirable fusing results. For instance, the distance between the rollers 26 and 27 may be shortened in the event that the rate of movement of the support material S through the electrostatic copying/duplicating machine utilizing the fuser apparatus 20 is relatively slow. On the other hand, for electrostatic duplicating machine arrangements capable of high speed reproduction wherein the speed of movement for the support material is relatively fast, it may be desirable to extend the distance between the rollers 26, 27 to compensate for the speed of the support material through the fuser apparatus.
  • sheet of support material such as paper is directed onto the belt 25 image side up and is tacked to the belt surface by corona discharge device 40 for transfer through the fuser apparatus.
  • Heat circulating within the fuser apparatus and that which is radiated directly from the heater element 30 is applied to the surface of the belt 25 which has very good thermal contact with the support material along the entire length thereof. Since the thickness of the belt 25 is in the order of 0.010 to 0.030 of an inch, it is small enough so that heat can be conducted through the belt with the heater element located on one side of the belt run and a toner image located on the other side. lt has been found that excellent fixes of the toner images including both solid area and line copy to moving support material are obtained with. temperatures as low as 380 F. at dwell times of about 0.80 to 1.0 second.
  • the response time for the heating element is relatively fast and, the heat that can be applied to a belt will be adequate for any copying/duplicating speed.
  • the fusing temperature is independent of the spectral absorption of the toner as in the case of radiant heaters.
  • the warm up period to bring the belt surface to a fusing temperature is relatively short and no standby periods are required for maintaining the heating elements ener ized before or during production runs of an electrostatic mac me. Since there IS a minimum loss of heat by way of conduction and radiation, the amount of energy necessary to energize the heating elements may be substantially reduced.
  • there is no pressure applied to the image there is no undesirable offset" of toner particles.
  • the amount of heat that the heating element 30 must supply is that which is given up to the toner particles and the support material plus the very small amount of heat that is lost in being transferred from its point of application to the support material.
  • a heat fusing apparatus for fixing thermoplastic particles carried on a support material in image configuration said apparatus including a thermally insulating housing, means to feed support material bearing heat fusible particles in image configuration into the housing along a predetermined path,
  • an endless belt member disposed in said housing made of a highly thermally conductive material mounted for carrying and moving said support material along the path and out of the housing,
  • said belt member being formed therearound with an electrically insulating material in laminar form
  • electrical discharge means arranged in the sheet path for electrically tacking said support material to said belt surface uniformly along the entire length thereof, and electrical heating means for applying heat to the side of said belt member opposite that side upon which the image particles to be fused and said electrically insulating laminar form are positioned during movement of said member, the heat being of sufficient temperature for tackifying and fixing the image upon the support material.
  • said belt member comprises a layer of copper material of a thickness ranging from about 0.010 to about 0.030 inch.
  • the apparatus of claim 4 including means for removing the support material from said belt member without causing offset of the heat fusible particles.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fixing For Electrophotography (AREA)
US851826A 1969-08-21 1969-08-21 Heat fixing apparatus Expired - Lifetime US3584195A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85182669A 1969-08-21 1969-08-21

Publications (1)

Publication Number Publication Date
US3584195A true US3584195A (en) 1971-06-08

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Family Applications (1)

Application Number Title Priority Date Filing Date
US851826A Expired - Lifetime US3584195A (en) 1969-08-21 1969-08-21 Heat fixing apparatus

Country Status (4)

Country Link
US (1) US3584195A (de)
JP (1) JPS5332262B1 (de)
DE (1) DE2041670A1 (de)
GB (1) GB1322354A (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3826892A (en) * 1972-10-25 1974-07-30 Xerox Corp Fusing apparatus
USRE28802E (en) * 1972-10-25 1976-05-04 Xerox Corporation Fusing apparatus
FR2301854A1 (fr) * 1975-02-19 1976-09-17 Xerox Corp Dis
JPS51130233A (en) * 1975-05-06 1976-11-12 Ricoh Co Ltd Fixing device
US4806733A (en) * 1987-02-19 1989-02-21 The Mead Corporation Radiant glossing apparatus for glossing developer sheets and a process for using the same
US6442365B1 (en) 1998-04-08 2002-08-27 Xerox Corporation Thermally conductive fuser belt
EP1248162A2 (de) * 2001-04-06 2002-10-09 NexPress Solutions LLC Vorheizeinheit für eine Fixierbaugruppe einer elektrostatischen Reproduktionsvorrichtung
US6594465B2 (en) * 2000-12-22 2003-07-15 Nexpress Solutions Llc Radiation unit for a fixation device
US20050158089A1 (en) * 2004-01-15 2005-07-21 Xerox Corporation Two stage fusing method and apparatus for high-speed full process color

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3079483A (en) * 1962-01-02 1963-02-26 Xerox Corp Xerographic fixing apparatus
US3397303A (en) * 1965-10-23 1968-08-13 Bell & Howell Co Conveying belt with integral electric heater and sheet member holddown means
US3432639A (en) * 1966-10-03 1969-03-11 Xerox Corp Fusing apparatus
US3515855A (en) * 1968-11-14 1970-06-02 Ibm Xerographic fusing apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3079483A (en) * 1962-01-02 1963-02-26 Xerox Corp Xerographic fixing apparatus
US3397303A (en) * 1965-10-23 1968-08-13 Bell & Howell Co Conveying belt with integral electric heater and sheet member holddown means
US3432639A (en) * 1966-10-03 1969-03-11 Xerox Corp Fusing apparatus
US3515855A (en) * 1968-11-14 1970-06-02 Ibm Xerographic fusing apparatus

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3826892A (en) * 1972-10-25 1974-07-30 Xerox Corp Fusing apparatus
USRE28802E (en) * 1972-10-25 1976-05-04 Xerox Corporation Fusing apparatus
US4102681A (en) * 1972-10-25 1978-07-25 Xerox Corporation Transfer and fusing method
FR2301854A1 (fr) * 1975-02-19 1976-09-17 Xerox Corp Dis
JPS51130233A (en) * 1975-05-06 1976-11-12 Ricoh Co Ltd Fixing device
US4806733A (en) * 1987-02-19 1989-02-21 The Mead Corporation Radiant glossing apparatus for glossing developer sheets and a process for using the same
US6442365B1 (en) 1998-04-08 2002-08-27 Xerox Corporation Thermally conductive fuser belt
US6594465B2 (en) * 2000-12-22 2003-07-15 Nexpress Solutions Llc Radiation unit for a fixation device
EP1248162A2 (de) * 2001-04-06 2002-10-09 NexPress Solutions LLC Vorheizeinheit für eine Fixierbaugruppe einer elektrostatischen Reproduktionsvorrichtung
EP1248162A3 (de) * 2001-04-06 2006-03-01 Eastman Kodak Company Vorheizeinheit für eine Fixierbaugruppe einer elektrostatischen Reproduktionsvorrichtung
US20050158089A1 (en) * 2004-01-15 2005-07-21 Xerox Corporation Two stage fusing method and apparatus for high-speed full process color

Also Published As

Publication number Publication date
GB1322354A (en) 1973-07-04
DE2041670A1 (de) 1971-03-04
JPS5332262B1 (de) 1978-09-07

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