US3868181A - Apparatus for driving photosensitive element in electrophotographic copier of image transfer type - Google Patents

Apparatus for driving photosensitive element in electrophotographic copier of image transfer type Download PDF

Info

Publication number
US3868181A
US3868181A US334532A US33453273A US3868181A US 3868181 A US3868181 A US 3868181A US 334532 A US334532 A US 334532A US 33453273 A US33453273 A US 33453273A US 3868181 A US3868181 A US 3868181A
Authority
US
United States
Prior art keywords
belt
suction box
drive roller
photosensitive
runs
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
US334532A
Other languages
English (en)
Inventor
Susumu Tanaka
Yuji Enoguchi
Takao Fujiwara
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.)
Minolta Co Ltd
Original Assignee
Minolta Co Ltd
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 Minolta Co Ltd filed Critical Minolta Co Ltd
Application granted granted Critical
Publication of US3868181A publication Critical patent/US3868181A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/28—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which projection is obtained by line scanning
    • G03G15/283—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which projection is obtained by line scanning using a reusable recording medium in form of a band

Definitions

  • An apparatus comprises a sheet of photosensitive element in the form of an endless belt, a drive roller for driving the photosensitive sheet in one direction, a suction box for sucking in a loop portion of the photo sensitive sheet supported on the roller and pressure reducing means for imparting a sucking force to the suction box.
  • the suction box regulates the direction of advance of the photosensitive sheet to prevent zigzag movement thereof and is provided with means for protecting and cleaning the photosensitive surface.
  • This invention relates to apparatuses for driving a photosensitive element in electrophotographic copiers of the image transfer type, more particularly to an apparatus for driving a photosensitive element in the form of an endless belt to be subjected to charging, exposure and image transfer operation for use in an electrophotographic copier of the electrostatic latent image transfer type in which an electrostatic latent image formed on the photosensitive element is transferred directly to copy paper or of the powder image transfer type in which the electrostatic latent image is developed with a toner powder to form a visual image and the visual image is subsequently transferred to copy paper.
  • the photosensitive sheet of the endless belt type is received around a drive roller and a tension roller and is driven under suitable tension.
  • endless photosensitive element tends to be deviated widthwise in zigzag fashion when driven and the zigzag movement becomes more pronounced if it is driven at an increased speed.
  • the photosensitive element is used repeatedly for the production of copies.
  • the element undergoes fatigue and deterioration in its image bearing surface and therefore becomes no longer serviceable, there arises a need to replace the element with a fresh one, whereas if the photosensitive element is in the form of an endless belt passed around and supported on two rollers, the element is very troublesome to replace and requires complex support and drive means.
  • the photosensitive sheet of the type described has another drawback that since it is always subjected to mechanical tension by the two rollers, the serviceable life of the element reduces.
  • An object of this invention is to provide an apparatus for use in an electrophotographic copier of the image transfer type for driving an endless sheet of photosensitive element free from zigzag movement.
  • Another object of this invention is to provide a driv- 'ing apparatus of a very simplified construction which permitsan old photosensitive element to be replaced with a fresh one with extreme ease.
  • Still another object of this invention is to provide a driving apparatus which is free from the necessity to mechanically give excess stress to the photosensitive element to tension the same so as to render the photosensitive element serviceable over a prolonged period of time.
  • a photosensitive sheet is supported on only one drive roller.
  • the photosensitive sheet per se is endless or is rendered endless by being adhered to an endless support belt.
  • the copier includes a suction box disposed in opposingrelation to the drive roller and adapted to suck in a loop portion of the endless sheet.
  • the suction box draws in the loop portion to impart tension to the sheet and to thereby keep the sheet planar.
  • the interior width of the suction box is nearly equal to the width of the photosensitive sheet such that the photosensitive sheet can travel along the inner wall of the suction box.
  • the suction box is further provided on its interior wall with soft cloth such as silicone cloth or with an equivalent material so as to protect and clean the surface of the photosensitive element as it moves slidingly along the interior wall of the suction box.
  • the suction box guides the travel of the photosensitive element without permitting the zigzag movement of the element. Further this invention employs no tension roller to extremely simplify the mechanism for driving the photosensitive sheet and to mitigate troubles to be encountered in replacing the photosensitive element.
  • the vacuum suction to be given to the suction box varies depending upon the thickness and size of the photosensitive sheet.
  • a suction for example of as low as 30 mm Aq. will achieve satisfactory results. Consequently, the mechanical tension given to the photosensitive sheet is very small so that the life of the photosensitive sheet can be extended a great deal.
  • FIG. 1 is a view in section showing the construction of principal part of an embodiment of this invention.
  • FIG. 2 is a view in section showing the construction of principal part of another embodiment of this invention.
  • FIG. 1 shows an embodiment of electrophotographic copier of the electrostatic latent image transfer type.
  • a document D is placed face down on a document table 1 made of a transparent material such as glass and is illuminated by an exposure system 2.
  • the reflected light from the surface of the document is led onto a photosensitive element P to form an image thereon for exposure, whereby the reverse of the image of the document is formed as an electrostatic latent image on the photosensitive element.
  • the exposure system 2 comprises first movable means including a lamp L and a reflecting mirror Ml; second movable means including reflecting mirrors M2 and M3; stationary means including an image-forming lens 3 and a reflecting mirror M4; and an exposure slit 4.
  • first movable means including a lamp L and a reflecting mirror Ml
  • second movable means including reflecting mirrors M2 and M3
  • stationary means including an image-forming lens 3 and a reflecting mirror M4
  • an exposure slit 4 As detailed in Publication of Japanese Patent Application No. 6647/1964, the first movable means travels at a velocity of v while the second movable means travels at a velocity of v12, so that in spite of the travel of both the movable means, the light path extending from the document surface to the image-forming lens 3 is maintained at a constant length all the time.
  • the first and second movable means travel reciprocally between the solid line position and the broken line position in the drawing, and the photosensitive element is exposed during the forward travel.
  • the photosensitive sheet P per se is endless or the sheet is rendered endless by being adhered to an endless support belt.
  • the sheet P is passed over a drive roller 5 which is driven by rolling contact with a feed roller 6.
  • the roller 6 is rotated by unillustrated drive means.
  • the photosensitive sheet P is driven at the same speed and in the same direction as the first movable means.
  • the roller 6 has a smaller diameter at its longitudinally central portion than at its opposite ends, which are in contact with the opposite ends of the drive roller 5 to rotate the same.
  • the copy paper 8 in the form of a roll is disposed within the machine.
  • the leader end of the paper 8 is led between the photosensitive surface and transfer belt 11 to transfer the image.
  • the copy paper 8 is cut to a predetermined dimension (copy size) by a cutter 12 disposed along the feed path of the paper.
  • the copy paper 8 bearing the transferred electrostatic latent image thereon is separated from the photosensitive surface upon passing over the transfer roller 10 and is sent to a developing unit 13, in which a toner in the developer is applied to the latent image to visualize thesame.
  • the paper is-then delivered onto a fixing belt 14 to fix the image by a fixing unit 15 disposed along the path of movement of the fixing belt 14. The paper is then sent out from the machine.
  • the copier includes a suction box 16 for sucking in a loop portion P of the endless photosensitive sheet P supported on the drive roller 5 so as to position the loop portion Palong the interior wall of the box 16 for sliding movement on the wall face when the drive roller 5 is driven.
  • Air is exhausted from the interior of the suction box 16 by pressure reducing means such as a simple exhaust fan 17 or the like to suck in the loopportion P.
  • the suction box 16 is further provided on its interior wall with a soft cloth 18 such assilicone cloth or with a suitable protective sheet adhered thereto to protect the photosensitive surface from defacement.
  • the cloth serves also as a cleaner when the photosensitive sheet P moves in sliding contact therewith.
  • the photosensitive sheet P is driven by the drive roller 5 in one direction at a speed equal to that of the first movable means of the exposure system 2 and subjected to charging, exposure and image transfer, upon completion of which the sheet is cleaned by the cloth. 18 or the like within the suction box.
  • the interior width of the suction box 16 is nearly equal to the width of the sheet P and is such as to permit the sliding movement of the photosensitive sheet P, so that the pressure reducing means 17 when actuated immediately causes the loop portion P of the photosensitive sheet P to extend its photosensitive surface along the interior wall surface of the suction box 16 in contact therewith.
  • the copy paper 8 bearing the powder image transferred thereto is peeled off the photosensitive sheet P and fed to a fixing unit 15 for the fixing of the powder image while being transported on a fixing belt 14. The paper is then sent out from the machine.
  • the suction box 16 must have a function to clean the remaining toner off the photosensitive surface after the completion of the image trans.- fer.
  • the suction box 16 is provided on its interior wall with a soft material having a high cleaning effect, such as rabbit hair 18, and a dust collector 25 is disposed behind the exhaust fan 17 to collect the toner and dust removed from the photosensitive surface.
  • a drive roller rotatable about a transverse axis
  • a suction box extending longitudinally relative to said drive roller and having in an end thereof proximate said drive roller an opening longitudinally spaced from and facing said drive roller, exhaust means communieating with said suction box at a point in said box spaced longitudinally inwardly of said end opening, and an endless belt having a photosensitive outer face and constrained to move in a path having longitudinal forward and return runs joined at opposite ends by respective first and second longitudinally spaced transverse end runs, said first transverse end run extending around said drive roller and said second transverse end run and a part of said longitudinal forward and return runs being disposed in said suction box so that the belt is tensioned under the influence of the reduced pressure therein, said suction box including opposite walls extending along the outer faces of said belt longitudinal runs and said walls having their inside faces lined with relatively soft webs engaging said belt outer faces in said suction box.
  • An image transfer type electrophotographic copier apparatus including charging, exposing and transferring stations comprising:
  • a photosensitive element in the form of an endless belt constrained to move in a path having longitudinal runs and a first looped end adjacent to said drive roller and an opposite second looped end, said belt in said first looped end coacting with said drive roller which drives the belt;
  • a suction box in covering relation to a portion of said belt including a sucking path leading to said pressure reducing means
  • said suction box including opposite walls extending along the outer faces of said longitudinal runs of said belt path and said walls having their inside faces lined with relatively soft webs engaging said belt outer faces in said suction box.
  • suction box means covers both the upper and lower surfaces of said belt except for the area where said belt traverses said charging, exposing and transferring stations 4.
  • width of said suction box covering said belt is essentially equal to the width of said belt for preventing the meandering of said belt.
  • suction box is formed with a protecting means for cleaning said photosensitive element.
  • An apparatus as claimed in claim 2 including a powder collecting means discharged from said pressure

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Discharging, Photosensitive Material Shape In Electrophotography (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
US334532A 1972-03-07 1973-02-22 Apparatus for driving photosensitive element in electrophotographic copier of image transfer type Expired - Lifetime US3868181A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1972027584U JPS48104341U (es) 1972-03-07 1972-03-07

Publications (1)

Publication Number Publication Date
US3868181A true US3868181A (en) 1975-02-25

Family

ID=12224997

Family Applications (1)

Application Number Title Priority Date Filing Date
US334532A Expired - Lifetime US3868181A (en) 1972-03-07 1973-02-22 Apparatus for driving photosensitive element in electrophotographic copier of image transfer type

Country Status (3)

Country Link
US (1) US3868181A (es)
JP (1) JPS48104341U (es)
DE (1) DE2310822A1 (es)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2944389A1 (de) * 1978-11-02 1980-05-08 Mita Industrial Co Ltd Elektrokopierer
US4370047A (en) * 1978-04-03 1983-01-25 Xerox Corporation High speed color apparatus
US5119133A (en) * 1989-08-25 1992-06-02 Xerox Corporation Packaged flexible photoconductive belt
US5390011A (en) * 1993-05-27 1995-02-14 Delphax Systems Compact imaging roll printer

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3442419A (en) * 1963-12-27 1969-05-06 Ibm Pneumatic belt device
US3495268A (en) * 1966-03-15 1970-02-10 Mohawk Data Sciences Corp Continuously moving endless band non-impact transfer printer
US3654901A (en) * 1969-08-06 1972-04-11 Xerox Corp Toner reclaiming system
US3694068A (en) * 1970-12-29 1972-09-26 Xerox Corp Roller retraction mechanism in a multiple roller belt assembly
US3723981A (en) * 1962-07-17 1973-03-27 Honeywell Inf Systems Pneumatic accessing of tape bands

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3723981A (en) * 1962-07-17 1973-03-27 Honeywell Inf Systems Pneumatic accessing of tape bands
US3442419A (en) * 1963-12-27 1969-05-06 Ibm Pneumatic belt device
US3495268A (en) * 1966-03-15 1970-02-10 Mohawk Data Sciences Corp Continuously moving endless band non-impact transfer printer
US3654901A (en) * 1969-08-06 1972-04-11 Xerox Corp Toner reclaiming system
US3694068A (en) * 1970-12-29 1972-09-26 Xerox Corp Roller retraction mechanism in a multiple roller belt assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4370047A (en) * 1978-04-03 1983-01-25 Xerox Corporation High speed color apparatus
DE2944389A1 (de) * 1978-11-02 1980-05-08 Mita Industrial Co Ltd Elektrokopierer
US5119133A (en) * 1989-08-25 1992-06-02 Xerox Corporation Packaged flexible photoconductive belt
US5390011A (en) * 1993-05-27 1995-02-14 Delphax Systems Compact imaging roll printer

Also Published As

Publication number Publication date
DE2310822A1 (de) 1973-09-13
JPS48104341U (es) 1973-12-05

Similar Documents

Publication Publication Date Title
GB1587735A (en) Image forming apparatus
US4008954A (en) Device for extinguishing unnecessary electrostatic charge in electrophotographic copier
JP2901994B2 (ja) プリンター装置
JPH05119678A (ja) 複式作動のブレード清掃装置
US3893760A (en) Transfer apparatus
US3751155A (en) Pre-development exposure assembly
US4841333A (en) Process unit for an imaging apparatus
US3868181A (en) Apparatus for driving photosensitive element in electrophotographic copier of image transfer type
US3807854A (en) Drive mechanism for photsensitive web in an image transfer type electrophotographic copier
US4801975A (en) Eraser lamp and transparent guide plate in electrostatic image transfer
EP0129750B1 (en) Electrographic apparatus
JPH01214550A (ja) 静電写真式複写機
JPH0682233B2 (ja) 電子写真装置
JP2928361B2 (ja) 像形成装置の清掃ブレードの塵の除去装置及び方法
JP3223024B2 (ja) 画像形成装置
US3827801A (en) Electrophotographic copier of image transfer type
US4682879A (en) Electrophotographic copier
JP3283980B2 (ja) 接触帯電装置
JPS6325345B2 (es)
JPS6086558A (ja) 複写装置
JP3577688B2 (ja) 画像形成装置
US4351602A (en) Electrostatic printer
EP0029953B1 (en) Electrophotographic copier including a belt photoconductor
JPS647382B2 (es)
JPH0544837Y2 (es)