US3901186A - Transfer roller assembly - Google Patents

Transfer roller assembly Download PDF

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Publication number
US3901186A
US3901186A US376086A US37608673A US3901186A US 3901186 A US3901186 A US 3901186A US 376086 A US376086 A US 376086A US 37608673 A US37608673 A US 37608673A US 3901186 A US3901186 A US 3901186A
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US
United States
Prior art keywords
transfer roller
roller
contact
transfer
point
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
US376086A
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English (en)
Inventor
Daniel S Hoffman
John Maksymiak
Frank S Sanza
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
Original Assignee
Xerox Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Priority to US376086A priority Critical patent/US3901186A/en
Priority to CA198,593A priority patent/CA1021008A/en
Priority to BE145876A priority patent/BE816848A/xx
Priority to DE2430754A priority patent/DE2430754C3/de
Priority to IT24588/74A priority patent/IT1015524B/it
Priority to GB2916074A priority patent/GB1471049A/en
Priority to BR5411/74A priority patent/BR7405411D0/pt
Priority to AU70668/74A priority patent/AU7066874A/en
Priority to FR7423024A priority patent/FR2236217B1/fr
Priority to NL7408968A priority patent/NL7408968A/xx
Application granted granted Critical
Publication of US3901186A publication Critical patent/US3901186A/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
    • G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
    • G03G15/1665—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer by introducing the second base in the nip formed by the recording member and at least one transfer member, e.g. in combination with bias or heat
    • G03G15/167—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer by introducing the second base in the nip formed by the recording member and at least one transfer member, e.g. in combination with bias or heat at least one of the recording member or the transfer member being rotatable during the transfer

Definitions

  • a transfer roller assembly having a transfer roller is mounted adjacent a curved photoconductive surface of an electrostatographic machine so that the transfer roller is biased into contact with the surface with a minimal force sufficient only to maintain uniform contact therewith during machine operation; the roller is mounted so that it may move in a direction which is at least generally perpendicular to a tangent at the point of contact.
  • the ratio of the radius of the photoconductive surface to that of the roller at the point of contact is not less than 3, and preferably in the range of 3 to 3.5.
  • This invention relates generally to electrostatography, but more particularly to a novel transfer roller assembly for an electrostatographic machine.
  • a xerographic surface comprising a layer of photoconductive insulating material affixed to a conductive backing is used to support electrostatic images.
  • the xerographic plate is electrostatically charged uniformly over its surface and then exposed to a light pattern of the image being reproduced to thereby discharge the charge in the areas where light strikes the layer.
  • the undischarged areas of the layer thus form an electrostatic charge pattern in conformity with the configuration of the original light pattern.
  • the latent electrostatic image may then be developed by contacting it with a finely divided electrostatically attractable material, such as a resinous powder.
  • a finely divided electrostatically attractable material such as a resinous powder.
  • the powder is held in the image areas by the electrostatic fields on the layer. Where the field is greatest, the greatest amount of material is deposited; and where the field is least, little or no material is deposited.
  • a powder image is produced in conformity with the light image of the copy being reproduced.
  • the powder is subsequently transferred to a sheet of paper or other transfer surface, and suitably affixed thereto to thereby form a permanent print.
  • the toner may be fixed to the paper by passing the latter between a heated roller and a second roller in pressure contact therewith, whereby the toner becomes fused to the sheet of paper.
  • the image is generally transferred to the image receiving member (e.g. paper) by passing such member between the photoconductive surface including the developed image and a transfer roller in contact therewith.
  • the image receiving member e.g. paper
  • Roller electrode transfer systems employ DC electric fields to move charged particles such as xerographic toner from first to second supporting surfaces, e.g., from a photoconductive surface to a sheet of paper. The purpose of this is to exert an electrical force on the charged particles that moves them from the first to the second surface.
  • bias roller transfer systems are described in US. Pat. Nos. 2,807,233; 2,068,555; 3,043,684; 3,267,840; 3,598,580; 3,625,146; 3,630,591; 3,691,993; 3,702,482; and 3,684,364, French Pat. No. 2,065,390, German Application OLS 2,102,634 and British Pat. Nos. 2,310,666 and 1,302,922.
  • a support member e.g., a sheet of paper
  • the transfer roller assembly which is supported within an electrostatographic machine adjacent a photoconductive surface.
  • the transfer roller assembly is comprised of two rigid frame assemblies rotatably supporting spring loaded pivoting arms in which the transfer roller is journalled for rotation; this structure provides the pressure contact between the transfer roller and the photoconductive surface.
  • the force biasing the transfer roller toward the photoconductive surface is that minimal force sufficient only to maintain uniform contact during operation of the machine.
  • the transfer roller is mounted so that any shift of the transfer roll during operation of the machine is in a direction which is at least generally perpendicular to a tangent at the point of contact.
  • the ratio of the radius of the curved photoconductive surface to the radius of the transfer roller at the point of contact is not less than 3, and preferably in the range of 3 to 3.5.
  • the transfer roller assembly of the present invention may operate as disclosed in US. patent application Ser. No. 309,562 filed on Nov. 24, 1972, or in other suitable conventional manners.
  • FIG. 1 is a schematic sectional view of an electrostatic reproduction machine embodying the principles of the present invention.
  • FIG. 2 is an elevational view of ,a transfer roller assembly embodying the principles of the present inventlon.
  • FIG. 3 is a sectional view of the transfer roller assembly of FIG. 2 taken along the line 3-3 of FIG. 2.
  • FIG. 4 is a side view of the transfer roller assembly taken along the line 4-4 thereof of FIG. 2.
  • a document D to be copied is placed upon a transparent support platen P fixedly arranged in an illumination assembly, indicated generally by the reference numeral l and positioned at the left end of the machine.
  • Light rays from an illumination system are flashed upon the document to produce image rays corresponding to the informational areas.
  • the image rays are projected by means of an optical system onto the photosensitive surface of a xerographic plate in the form of a flexible photoconductive belt 12 arranged on a belt assembly, generally indicated by the reference numeral 14.
  • the belt 12 comprises a photoconductive layer of selenium which is the light receiving surface and imaging medium for the apparatus, on a conductive backing.
  • the surface of the photoconductive belt is made photosensitive by a previous step of uniformly charging the same by means of a corona generating device 13.
  • the belt isjournalled for continuous movement upon three rollers 20, 21, and 22 positioned with their axes in parallel relationship.
  • the photoconductive belt assembly 14 is slidably mounted upon two support shafts 23 and 24 secured to the frame of the apparatus with the roller 22 rotatably supported on the shaft 23, and is rotatably driven by a suitable motor and drive assembly (not shown) in the direction of the arrow at a constant rate.
  • a suitable motor and drive assembly (not shown) in the direction of the arrow at a constant rate.
  • the portion exposed is that portion of the belt running between rollers and 21.
  • the reflected light images of such original document positioned on the platen is flashed on the surface of the belt to produce an electrostatic latent image thereon at exposure station A.
  • the electrostatic image passes through a developing station B in which there is positioned a developer assembly, generally indicated by the reference numeral 15, and which provides development of the electrostatic image by means of multiple brushes 16 as the same moves through the development zone.
  • the developed electrostatic image is transported by the belt to a transfer station C wherein the transfer roller assembly 26 of the present invention is positioned and where a sheet of copy paper is moved between the nip formed by the assembly 26 and the belt 12.
  • the paper is moved at a speed in synchronism with the moving belt, and the transfer of the developed image is accomplished solely by an electrical bias on the transfer roller.
  • a sheet transport mechanism generally indicated at 28 adapted to transport sheets of paper from a paper handling mechanism generally indicated by the reference numeral 30 to the developed image on the belt at the station C.
  • the sheet After the sheet is stripped from the belt 12, it is conveyed into a fuser assembly, generally indicated by the reference numeral 31 wherein the developed and transferred xerographic powder image on the sheet material is permanently affixed thereto. After fusing, the finished copy is discharged from the apparatus at a suitable point for collection externally of the apparatus.
  • the transfer roller assembly 26 is illustrated, the assembly being comprised of a transfer roller 32, pivoting arms 34a and 34b, and rigid frame assemblies 36a and 36b.
  • the transfer roller 32 is mounted for rotation about shafts 38 disposed in arms 34a and 3411, the latter being joumalled for rotation about shafts 40 positioned within the assemblies 36a and 36b, respectively, such that any perturbations of the transfer roller 32 against the photoconductive belt 12 due to dimensional variations will not be deleterious to the image transfer process.
  • a support shaft 42 is mounted for rotation in the assemblies 36a and 36b above and in parallel alignment with the transfer roller 32, and a gear 44 is affixed to an end of the shaft 42 for driving a cleaning brush member 48 through a suitable drive means in contact with the transfer roller 32.
  • Bearings 50 are disposed on the shaft 42 outwardly of the assemblies 36a and 36b, and are positioned in support assemblies of the machine indicated generally as 52 and 54.
  • Shafts 38 are journalled for rotation in the pivoting arms 34a and 34b as are the shafts 40, thereby permitting rotation of the transfer roller 32 with respect to the arms 34a and 34b, and also permitting the transfer roller 32, and assemblies 34a and 34b to rotate as a unit about the shafts 40.
  • a shaft disposed above and in parallel relationship to the shafts 40, is joumalled for rotation in the assemblies 36a and 36b and has the portions thereof extending beyond these assemblies provided with earns 62 affixed thereto.
  • a threaded rod member 64 is rotatably mounted by a pin 66 to each of the assemblies 36a and 36b.
  • the end of the threaded rod member 64 opposite the pin mount is provided with a centrally formed orifice (not shown) into which a rod member 'is positioned in sliding relationship.
  • a spring 68 is positioned about the rod member 65 between each of the arms 34a and 34b and a nut 70 threaded on the rod 64.
  • a lever 72 is connected to the shaft 60 to rotate the latter and is held in operative relationship by a locking arm 74 extending from the assembly 36b.
  • the transfer roller 32 will contact the photoconductive surface in a manner to provide even contact therebetween similar to the shock absorbing action of the front end of a vehicle and that the compressional forces of the springs 68 are adjustable by rotation of the respective nuts 78.
  • Another aspect of the present invention relates to the ratio of A, the radius of photoconductive belt 12 at the point of contact with the transfer roller 32 to B, the radius of the transfer roller at that point.
  • This ratio should not be less than 3, and preferably is in the range of 3 to 3.5.
  • Apparatus comprising:
  • a transfer roller assembly having a transfer roller in contact with the surface, wherein the ratio of (i) the distance from the surface at the point of contact to the center of curvature of the surface at that point to (ii) the radial dimension of the roller, is not less than 3;

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Paper Feeding For Electrophotography (AREA)
US376086A 1973-07-02 1973-07-02 Transfer roller assembly Expired - Lifetime US3901186A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US376086A US3901186A (en) 1973-07-02 1973-07-02 Transfer roller assembly
CA198,593A CA1021008A (en) 1973-07-02 1974-04-25 Transfer roller assembly
BE145876A BE816848A (fr) 1973-07-02 1974-06-25 Dispositif de montage de rouleau de transfert pour machine electrostatographique
DE2430754A DE2430754C3 (de) 1973-07-02 1974-06-26 Übertragungseinrichtung zum Übertragen eines Tonerbildes
IT24588/74A IT1015524B (it) 1973-07-02 1974-06-28 Apparecchiatura di trasferimento per macchina elettrostatografica
GB2916074A GB1471049A (en) 1973-07-02 1974-07-01 Transfer roller assembly in a reproduction machine
BR5411/74A BR7405411D0 (pt) 1973-07-02 1974-07-01 Aparelho eletrostatografico
AU70668/74A AU7066874A (en) 1973-07-02 1974-07-01 Roller assembly
FR7423024A FR2236217B1 (xx) 1973-07-02 1974-07-02
NL7408968A NL7408968A (xx) 1973-07-02 1974-07-02

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US376086A US3901186A (en) 1973-07-02 1973-07-02 Transfer roller assembly

Publications (1)

Publication Number Publication Date
US3901186A true US3901186A (en) 1975-08-26

Family

ID=23483656

Family Applications (1)

Application Number Title Priority Date Filing Date
US376086A Expired - Lifetime US3901186A (en) 1973-07-02 1973-07-02 Transfer roller assembly

Country Status (10)

Country Link
US (1) US3901186A (xx)
AU (1) AU7066874A (xx)
BE (1) BE816848A (xx)
BR (1) BR7405411D0 (xx)
CA (1) CA1021008A (xx)
DE (1) DE2430754C3 (xx)
FR (1) FR2236217B1 (xx)
GB (1) GB1471049A (xx)
IT (1) IT1015524B (xx)
NL (1) NL7408968A (xx)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4087169A (en) * 1975-11-14 1978-05-02 Xerox Corporation Transfer roller system
US4119059A (en) * 1975-04-15 1978-10-10 Develop Kg Dr. Eisbein & Co. Mounting arrangement for component elements of a copying machine
US5318631A (en) * 1990-12-18 1994-06-07 Sharp Kabushiki Kaisha Pressure control device for a pressure roller
US5378525A (en) * 1992-07-23 1995-01-03 Tokai Rubber Industries, Ltd. Crowned resilient roll with coating layer and method of producing the same
US6175711B1 (en) * 1998-10-16 2001-01-16 Fuji Xerox Co., Ltd. Image forming apparatus having a toner diffuser

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5101238A (en) * 1991-01-18 1992-03-31 Eastman Kodak Company Roller transfer assembly

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3071070A (en) * 1955-03-01 1963-01-01 Xerox Corp Method and apparatus for transferring images from xerographic to metallic plates
US3072026A (en) * 1958-03-18 1963-01-08 Messrs F Soennecken Automatic contact printers for electrostatic reproductions
US3132050A (en) * 1960-04-04 1964-05-05 Xerox Corp Xerographic transfer apparatus
US3751156A (en) * 1971-10-21 1973-08-07 Agfa Gevaert Ag Electrostatic copying apparatus with means for preventing contamination of transfer material

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3071070A (en) * 1955-03-01 1963-01-01 Xerox Corp Method and apparatus for transferring images from xerographic to metallic plates
US3072026A (en) * 1958-03-18 1963-01-08 Messrs F Soennecken Automatic contact printers for electrostatic reproductions
US3132050A (en) * 1960-04-04 1964-05-05 Xerox Corp Xerographic transfer apparatus
US3751156A (en) * 1971-10-21 1973-08-07 Agfa Gevaert Ag Electrostatic copying apparatus with means for preventing contamination of transfer material

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4119059A (en) * 1975-04-15 1978-10-10 Develop Kg Dr. Eisbein & Co. Mounting arrangement for component elements of a copying machine
US4087169A (en) * 1975-11-14 1978-05-02 Xerox Corporation Transfer roller system
US5318631A (en) * 1990-12-18 1994-06-07 Sharp Kabushiki Kaisha Pressure control device for a pressure roller
US5378525A (en) * 1992-07-23 1995-01-03 Tokai Rubber Industries, Ltd. Crowned resilient roll with coating layer and method of producing the same
US5455077A (en) * 1992-07-23 1995-10-03 Tokai Rubber Industries, Ltd. Method of producing a crowned resilient roll with coating layer
US6175711B1 (en) * 1998-10-16 2001-01-16 Fuji Xerox Co., Ltd. Image forming apparatus having a toner diffuser

Also Published As

Publication number Publication date
GB1471049A (en) 1977-04-21
NL7408968A (xx) 1974-09-25
AU7066874A (en) 1976-01-08
DE2430754A1 (de) 1975-01-23
BE816848A (fr) 1974-10-16
FR2236217A1 (xx) 1975-01-31
DE2430754B2 (de) 1980-06-12
FR2236217B1 (xx) 1977-06-24
DE2430754C3 (de) 1981-02-26
CA1021008A (en) 1977-11-15
IT1015524B (it) 1977-05-20
BR7405411D0 (pt) 1975-03-25

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