CA1036418A - Reproduction machine with textured transfer roller - Google Patents

Reproduction machine with textured transfer roller

Info

Publication number
CA1036418A
CA1036418A CA208,490A CA208490A CA1036418A CA 1036418 A CA1036418 A CA 1036418A CA 208490 A CA208490 A CA 208490A CA 1036418 A CA1036418 A CA 1036418A
Authority
CA
Canada
Prior art keywords
roller
sheet
transfer roller
reproduction machine
peaks
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
Application number
CA208,490A
Other languages
French (fr)
Inventor
Donald A. Seanor
James A. Lentz
Thomas Meagher
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
Priority to US41006373A priority Critical
Application filed by Xerox Corp filed Critical Xerox Corp
Application granted granted Critical
Publication of CA1036418A publication Critical patent/CA1036418A/en
Expired legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/14Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16Apparatus 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
    • G03G15/1665Apparatus 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
    • G03G15/167Apparatus 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
    • G03G15/1685Structure, details of the transfer member, e.g. chemical composition

Abstract

ABSTRACT OF THE DISCLOSURE
An electrostatic reproduction machine has a photo-conductive member and a transfer roller in contact therewith, the roller having a texturized surface formed so as to prevent or minimize the possibility of a sheet of paper wrapping itself around the roller as the sheet is passing between the photoconductive member and the roller during the transfer operation.

Description

~36~8 BACKGROU~ID OF THE INVENT ION
This invention relates to an electrostatographic ~ machine, but more particularly to such a machine having a ; novel transfer roller.
In the practice of xerography a xerographic surface comprising a layer of pho-toconductive insulating material affixed to a conductive backing is used to support electro-static images. In the usual method of carrying out the process, the xerographic plate is electrostatically charged lmiformly 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 develop-ed by contacting it with 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 the greatest, the greatest amount of material is deposited; and where the field is the least, little or no material is deposited. Thus, a powder image is produced in conformity with the light image of the copy being reproduced. The powder image is subseguently transferred to a sheet of paper or other surface and suitably affixed thereto to form a permanent print. The powder image may be affixed by passing the sheet of paper or other surface having the transferred image between a heated roller and a ~ 2 ~ ~

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~3~
second roller in pressure contact therewith, whereby the powder image becomes fused to the sheet of paper.
The powder image is sometLmes transferred to an image recelving member by passing the member between the photoconductive 9Lal36~18 surface including the developed image and a biased transfer roller in contact therewith. One of the problems sometimes encountered in using a biased transfer roller is that the paper tends to wrap itself around the roller during the transfer step or operation. Thus, what is needed is a trans-fer roller which will eliminate or minimize this paper wrapping problem.
_ MMARY OF THE INVENTION
In accordance with this invention there is provided a reproduction machine having a photoconductive surface, means for forming a developed electrostatic image on said surface, a transfer roller in contact with said surface and mounted for rotation, means for feeding a sheet of support material between said surface and said transfer roller so that transfer of said developed electrostatic image from said surface to said sheet can be effected as the sheet is moved between said surface and said roller, said roller having a textured surface which inhibits the sheet from electrostatically tacking itself to said transfer roller during transfer while simultaneously causing the sheet to electrostatically tack itself to said surface.
BRIEF DESC~IPTION OF THE DRAWINGS
This invention will become more apparent upon consideration of the following detailed disclosure thereof, ; especially when taken with the accompanying drawings, wherein l~ke numerals designate like parts throughout.

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" ~

Figure 1 is a schematic sectional view of an electro-static reproduction machine embodying the principles of the lnvention; and ; Figures 2, 3, and 4 are partial enlarged views of the transfer roller of the invention.
DETAILED DESCRIPTION OF THE I~IENTION
For a general understanding of the illustrated copier/
reproduction machine in which the invention may be incorporated, reference is had to Figure 1 in which the various system com-ponents for the machine are schematically illustrated.
A document D to be copied is placed upon a transparent support~platen P fixedly arranged in an illumination assembly, generally indicated by the reference numeral 10, positioned at the left end of the machine. Light rays from the illumination system are flashed upon the document to produce image rays corresponding tG the informational areas. The image rays are projected by means of an optical system onto the photosensitive surface o~ a xerographic plate in the form of a flexible photo-; conductive belt 12 arranged on a belt assembly, generally indi-cated 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 gen-erating device 13.
The belt is journaled for continuous movement upon three rollers 20, 21, and 22 positioned with their axes in parallel. The photoconductive belt assembly 14 is slidably~
mounted upon two support shafts 23 and 24 with the roller 22 ~0~ L8 rotatably supported on the shaft 23 which is secured to the frame of the apparatus and is rotatably driven by a suitable motor and drive assembly (not shown) in the direction of the arrow at a constant rate. During exposure of the belt 12, the portion exposed is that portion of the belt running between rollers 20 and 21. During such movement of the belt 12, the reflected light image 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.
As the belt surface continues its movement, the electrostatic image passes through a developing station B in which there is positioned a developer assembly generally indica-ted by the referen,ce numeral lS, and which provides development of the e~ectrostatic image by means of multiple brushes 16 as the same moves through the develapment zone.
The developed electrostatic image is transported by th,e belt to a transfer station C where the present invention is positioned,and where a sheet of copy paper is moved be-tween a transfer roller and the belt at a speed in synchronism with the moving belt in order to accomplish transfer of the developed image solely by an electrical bias on the transfer roller. There is provided at this station a sheet transport mechanism generally indicated at 17 adapted to transport sheets of paper from a paper handling mechanism generally indicated by

2 the reference numeral 18 to the developed image on the belt at the station C.
After the sheet is stripped from the belt 12, it is conveyed into a fuser assembly, generally indicated by the reference numeral 19, wherein the developed and transferred xerographic powder image on the sheet material is permanently ~( 136~
affixed thereto. After fusing, the finished copy is dis-charged from the apparatus at a suitable point for collection externally of the apparatus.
Referring to Figure 2, there is illustrated a transfer roller generally indicated as 30 having a texturized surface formed by covering a roller per se 32 with a textured material 34, e.g., nylon as used for nylon stockings.
Figure 3 shows a texturized roller 36 formed by grinding the surface of a conventional transfer roller with a grinding wheel to develop a texturized surface 38. The peak to valley dimension of the surface which is ground is preferably in the range of 2 to 8 mils, and the frequency of the peaks is preferably about 40 peaks per linear inch or greater, but may be as low as 20 to 30 peaks per linear inch depending upon the criteria regarding "print-out". This latter phrase refers to the impression of the texturized ; surface on the sheet of paper or other surface to which the powder image is being transferred.
Figure 4 shows a conventional transfer roller 40 on which a texturized surface is formed by winding a strand of nylon monofilament 42 around the roller at an angle to the rotational axis of the roller to produce a continuous annular groove 44 around the surface.
As stated above various other means may also be used to produce a texturized surface on a transfer roller.
A texturized surface can also be formed by coating a transfer roller with a thermal setting resin that has some tack time before curing, and then sprayed with particulate material such as various carbon black filled materials or polyvinyl-chloride. The particulate coating is then contacted`by a doctor blade while the roller is rotating so that a uniform thickness is deposited around the roller.
A texturized surface may also be formed by embossing the surface of the roller. This is effected by coating a conventional transfer roller with a clear resin, and when the resin reaches a pseudo-plastic state, rolling the roller over a heated screen to form a pattern on the surface of the roller.
The theory of operation of the above roller is believed to be the following: Breakdown (ionization) of the air occurs between the transfer roller and the photoreceptor.
If a sheet of paper passing between the roller and the photo~
receptor is closer to the photoreceptor as it exits the nip, it will be positively charged and tack itself to the photo-receptor, and will later be detacked to pass along its normal paper path. If the paper is closer to the transfer roller, it will be negatively charged and tack itself to the transfer roller. To prevent or minimize the possibility of the latter happening, the surface of the transfer roller is texturized.
This results in having the air breakdown occur in the "valleys"
of the texturized surface while the "peaks~ of the surface hold the paper away from the transfer roller and allow it to tack itself to the photoreceptor.
While the invention has been described with reference to the structure disclosed, it is not confined to the details set forth but is intended to cover such modifications or changes as may come within the scope of the following claim.

Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A reproduction machine having a photoconductive surface, means for forming a developed electrostatic image on said surface, a transfer roller in contact with said surface and mounted for rotation, means for feeding a sheet of support material between said surface and said transfer roller so that transfer of said developed electrostatic image from said surface to said sheet can be effected as the sheet is moved between said surface and said roller, said roller having a textured surface which inhibits the sheet from electrostatical-ly tacking itself to said transfer roller during transfer while simultaneously causing the sheet to electrostatically tack itself to said surface.
2. A reproduction machine according to Claim 1, wherein said textured surface is composed of peaks and valleys, the peak to valley dimension being in the range of two to eight mils.
3. A reproduction machine according to Claim 1, wherein said textured surface is composed of peaks and valleys, the frequency of occurrence of said peaks being up to about forty peaks per linear inch.
4. A reproduction machine according to Claim 3, wherein said frequency is from twenty to thirty peaks per linear inch.
5. A reproduction machine according to Claim 2, wherein the frequency of occurrence of said peaks is up to forty peaks per linear inch.
CA208,490A 1973-10-24 1974-09-04 Reproduction machine with textured transfer roller Expired CA1036418A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US41006373A true 1973-10-24 1973-10-24

Publications (1)

Publication Number Publication Date
CA1036418A true CA1036418A (en) 1978-08-15

Family

ID=23623055

Family Applications (1)

Application Number Title Priority Date Filing Date
CA208,490A Expired CA1036418A (en) 1973-10-24 1974-09-04 Reproduction machine with textured transfer roller

Country Status (6)

Country Link
JP (2) JPS5074435A (en)
CA (1) CA1036418A (en)
DE (1) DE2443021C3 (en)
FR (1) FR2249373B1 (en)
GB (1) GB1482657A (en)
NL (1) NL7412270A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5288031A (en) * 1976-01-19 1977-07-22 Konishiroku Photo Ind Co Ltd Tranfer auxiliary means for electrophotographic copying machine
JPS57202548A (en) * 1981-06-08 1982-12-11 Fujiretsukusu Kk Roller transferring method for electrophotographic image

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3759573A (en) * 1972-04-12 1973-09-18 Cmi Corp Bottom-dumping trailer with shiftable closure assembly

Also Published As

Publication number Publication date
CA1036418A1 (en)
DE2443021C3 (en) 1979-11-22
FR2249373A1 (en) 1975-05-23
DE2443021B2 (en) 1979-03-22
GB1482657A (en) 1977-08-10
JPS58131064U (en) 1983-09-05
DE2443021A1 (en) 1975-04-30
FR2249373B1 (en) 1978-03-24
NL7412270A (en) 1974-12-30
JPS5074435A (en) 1975-06-19

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