US3682137A - J-shell developer housing - Google Patents

J-shell developer housing Download PDF

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Publication number
US3682137A
US3682137A US6609A US3682137DA US3682137A US 3682137 A US3682137 A US 3682137A US 6609 A US6609 A US 6609A US 3682137D A US3682137D A US 3682137DA US 3682137 A US3682137 A US 3682137A
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United States
Prior art keywords
developer
charge
toner
housing structure
means disposed
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
US6609A
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English (en)
Inventor
Charles F Roth Jr
Gordon C Butler
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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 US3682137A publication Critical patent/US3682137A/en
Anticipated expiration legal-status Critical
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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
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/082—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer for immersion

Definitions

  • ABSTRACT Shell developer for electrostatic imaging apparatus.
  • the shell structure is characterized by a .l-shaped configuration having disposed within the shell a partition and baffle arrangement which effects movement of carrier particles and unused toner such that they are mixed with newly dispensed toner as the former and the latter strike the battle which is disposed above the developer supply level in the shell.
  • This invention relates, in general, to electrostatic imaging and, more particularly, to structure for developing electrostatic images.
  • a plate comprising a conductive backing upon which is placed a photoconductive insulating material, is unifomily charged and subsequently exposed through a suitable lens and lamp combination to an object to be reproduced.
  • the photoconductive material or coating becomes conductive in accordance with light patterns through the lens thereby discharging certain areas of the unifonn charge leaving a latent electrostatic image thereon.
  • the development of the latent image is generally effected by electrostatic attraction of finely divided pigmented resin to the latent image, the amount of charge found in image areas determining the amount of resin attracted thereto.
  • a permanent record of the object is obtained through transfer of the developed latent image to a permanent record media with subsequent fixing of the resin.
  • the toner material as these resins are commonly referred to, is generally conveyed to the image areas by means of a relatively larger and coarser material known as a carrier, the carrier being adapted to support a quantity of toner upon its surface.
  • a carrier a relatively larger and coarser material known as a carrier
  • the developer constitutes a two-component mixture which components are selected such that the materials interact electrostatically when brought into rubbing contact thereby causing a triboelectric attraction therebetween.
  • the cascade development process in automatic systems comprises a developing unit including an outer container or cover with a trough at its bottom containing a supply of developing material.
  • the developing material is picked up from the bottom of the container and dumped or cascaded over the surface of the xerographic plate by a number of buckets on an endless driven conveyor belt.
  • This development technique utilizes a two-element development mixture including finely-divided, colored, marking particles or toner and grossly larger carrier beads.
  • the carrier beads serve both to deagglomerate the toner particles and to charge them by virtue of the relative position of the toner and the carrier material in the triboelectric series.
  • the developer material i.e., unattracted toner and carrier beads
  • the developer material upon being released from the imaging surface, returns to the developer supply via the far side of the developer housing and approximately the top of the developer supply where it is replenished with toner before circulating back to the zone of active development.
  • the general object of this invention is to provide a new and improved electrographic or electrophotographic recording apparatus.
  • Another object of this invention is to provide structure for mixing newly dispensed toner and already used developer material prior to their return to the developer supply.
  • a shell developer structure or housing having a generally J-shaped configuration in cross secdeveloper by frictional forces created, upwardly between the web and the partition.
  • the distance between the two is substantially constant such that developer is carried to the top edge of the partition where it moves over to the opposite side thereof.
  • a toner dispenser is positioned over the shell intermediate the partition and the outer wall of the shell thereby allowing newly added toner to be mixed with already used developer prior to their return to the developer supply.
  • a baffle structure is interposed between the toner dispenser and the developer supply such that the newly added toner and the already used developer simultaneously strike the baffle.
  • FlG. l is an illustration of the basic flow-contact concept of developer mixing as found in the prior art.
  • PM]. 2 is an elevational view of recording apparatus representing the invention.
  • reference character ll ll designates generally a structure which diagrammatically depicts the basic flow-contact system which as noted hereinabove is found in the prior art.
  • a drum 1111 is rotated so as to move in the direction indicated through a cresent-shaped housing 32.
  • the housing contains sufficient developer material so that the drum surface continually moves in contact with the developer material as it moves through the housing.
  • the developer material 113 constitutes a twoelement mixture including finely-divided, colored marking particles or toner and grossly larger carrier beads.
  • a frictional force is established between the moving drum surface and the developer material causing a thin layer of developer material adjacent to the drum surface to move in an uphill direction.
  • the upward movement of developer material creates a void at the bottom of the housing which is filled as the entire back layer of developer moves down more or less as a unit.
  • a flow of developer material is thus established within the housing as indicated by the arrows. Satisfactory results have been obtained using semi-micro toner particles on the order of 5 microns in combination with uncoated nickel carrier beads on the order of 450 microns in size.
  • the path followed by the uphill flow of developer material as it moves in contact with the drum surface describes the active development zone.
  • Theoretically, properly charged and toned developer material is delivered to the start of the active development zone from the supply of developer material found on the back side of the system.
  • the developer material develops a latent image on the drum as it flows along in contact with the drum through the active development zone.
  • toner is electrostatically attracted from the carrier material to the more highly charged image areas. Because of the relatively gentle action of All the flow established within the housing, little or no toner is mechanically dislodged from the carrier material.
  • the developer material continues to move along in contact with the moving drum surface until the frictional forces holding it to the drum are overcome, as for example by the drum moving out of contact with the developer material.
  • the relatively depleted developer material returns to the back side of the system where it is replaced as it moves down to fill the void left by the continuous flow of upwardly moving material. It can be seen that the uppermost edge of the housing 12 is spaced farther from the drum llll than other portions thereof. This spacing coupled with the aforementioned movement of the drum away from the developer allows the forces of gravity to effect return of the developer material as previously mentioned.
  • the improved recording apparatus constituting the invention is shown in FIG. 2 and is generally indicated by reference character lb.
  • the apparatus lb comprises a charge-retentive belt or web l? which may, for example, consist of a conducting base of brass or electroformed nickel having disposed thereon a photoconductive layer of well known composition as found in the art.
  • the belt ll'7 is transported by upper and lower roller members l8, only the lower one of which is shown.
  • a charging device 119 is provided, which in accordance with well known principles, places a uniform electrostatic charge on the web at it passes thereunder.
  • the belt is then exposed to an object or material to be reproduced through a lens structure 211.
  • a conventional lamp not shown, provides necessary light activity to discharge areas of the belt in accordance with light reflected from the object to thereby leave a latent electrostatic image on the belt.
  • the belt having the latent image is then moved through a housing structure or shell 22 having a substantially l-shaped configuration having an upwardly and outwardly extending wall 25.
  • a two-component developer 23 which is the same as the material 113 is contained in the housing structure, the toner component thereof being attracted to the image bearing surface.
  • the belt is moved in an upward direction intermediate a vertically oriented partition 24 and a web guide or support 26. While the circulation of the developer material is similar, in the developer supply or sump area, to that described with reference to FIG.
  • the present apparatus differs in that the developer material is carried upwardly between the web and the partition to the top edge of the partition where if falls back to the developer supply on the reverse side of the partition in an area intermediate the partition and the housing structure.
  • the partition may be fabricated from various materials, for example, aluminum.
  • the developer contacting side of the partition is preferably smooth to thereby minimize toner buildup thereon.
  • a baffle member 27 attached to the partition 24 intercepts the unused developer materials from the supply as well as toner particles 28 which are added to the developer supply from a toner hopper or dispenser 29.
  • the dispenser 29 may be of any conventional construction suitable for metering toner at a desired rate, so long as the outlet therefrom is disposed above the baffle 27 as shown.
  • a structure suitable for this application is described in US. Pat. No. 3,013,703 issued in the name of R. A. Hunt.
  • the developed image is transferred to a transfer web 31 with the image being subsequently rendered permanent by suitable fusing means, not shown.
  • the belt is then cleaned in a conventional manner whereupon the belt is ready for another cycle of operation.
  • a transfer corotron 32 is provided for' accomplishing transfer to the web.
  • bafile structure 27 causes the aforementioned material to be mixed prior to the return to the sump area thus overcoming the problem of stagnated pockets of toner and/or already used developer materials. Furthermore, longer contact is provided between developer and recording medium thereby providing a system capable of operational speeds which are greater than those heretofore found in the prior art.
  • the partition and baffle members 24 and 27 could be replaced by a triangular-shaped belt arrangement mounted for free movement by the upward movement of the developer material.
  • One side of the belt would occupy the plane of the partition 24 while another side thereof would be in the plane of the baffle 27.
  • the partition alone could be replaced by a freely movable .belt which would cooperate with a stationary baffle similar to the bafile 27. The effect of the foregoing, it is thought, would enhance the laminar flow of the developer material due to the reduced frictional effects.
  • Apparatus for developing a latent electrostatic image on a charge-retentive surface comprising:
  • housing structure capable of holding a quantity of developer material and being so constructed as to cause contacting of said charge-retentive surfac by said developer material;
  • toner dispensing means disposed above said sump area and intermediate said partition and upwardly extending wall of said housing structure whereby dispensed toner is mixed with carrier material and unused toner prior to their return to the developer sump area;
  • baffle structure vertically disposed intermediate the outlet from said toner dispenser and the top level of developer in said sump, said baffle structure being so positioned as to form a mixing zone for newly added toner and unused toner and carrier particles.
  • Apparatus for developing a latent electrostatic image on a charge-retentive surface comprising:
  • housing structure capable of holding a quantity of developer material and being so constructed as to cause contacting of said charge-retentive surface by said developer material
  • the spacing between said partition and an upwardly extending wall of said housing structure is greater at the top of said wall than at the bottom.
  • said movable charge-retentive surface comprises an elongated recording web.
  • Apparatus for developing a latent electrostatic image on a charge-retentive surface comprising:
  • housing structure capable of holding a quantity of developer material and being so constructed as to cause contacting of said charge-retentive surface by said developer material
  • baffle structure vertically disposed intermediate the outlet from said toner dispenser and the top level of developer in said sump, said baffle structure being so positioned as to form a mixing zone for newly added toner and unused toner and carrier particles;
  • bafi'le structure being integral to said partition and inclined at an acute angle thereto such that mixed materials slide downwardly into the housing structure.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
US6609A 1970-01-28 1970-01-28 J-shell developer housing Expired - Lifetime US3682137A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US660970A 1970-01-28 1970-01-28

Publications (1)

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US3682137A true US3682137A (en) 1972-08-08

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US6609A Expired - Lifetime US3682137A (en) 1970-01-28 1970-01-28 J-shell developer housing

Country Status (6)

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US (1) US3682137A (ja)
JP (1) JPS5036767B1 (ja)
CA (1) CA949820A (ja)
DE (1) DE2104053A1 (ja)
GB (1) GB1342782A (ja)
NL (1) NL7100934A (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3823689A (en) * 1971-09-29 1974-07-16 Philips Corp Developing device for electrostatic charge images
US4108111A (en) * 1977-05-31 1978-08-22 Xerox Corporation Developer housing

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2832311A (en) * 1956-01-10 1958-04-29 Haloid Co Apparatus for development of electrostatic images
US3448724A (en) * 1968-01-11 1969-06-10 Xerox Corp Developing apparatus
US3503776A (en) * 1966-02-21 1970-03-31 Xerox Corp Xerographic development
US3599604A (en) * 1968-01-11 1971-08-17 Xerox Corp Xerographic development apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2832311A (en) * 1956-01-10 1958-04-29 Haloid Co Apparatus for development of electrostatic images
US3503776A (en) * 1966-02-21 1970-03-31 Xerox Corp Xerographic development
US3448724A (en) * 1968-01-11 1969-06-10 Xerox Corp Developing apparatus
US3599604A (en) * 1968-01-11 1971-08-17 Xerox Corp Xerographic development apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3823689A (en) * 1971-09-29 1974-07-16 Philips Corp Developing device for electrostatic charge images
US4108111A (en) * 1977-05-31 1978-08-22 Xerox Corporation Developer housing

Also Published As

Publication number Publication date
DE2104053A1 (de) 1971-08-12
CA949820A (en) 1974-06-25
NL7100934A (ja) 1971-07-30
JPS5036767B1 (ja) 1975-11-27
GB1342782A (en) 1974-01-03

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