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
  • G03G15/06—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
  • G03G15/0806—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller
  • G03G15/0808—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller characterised by the developer supplying means, e.g. structure of developer supply roller
• • 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
  • G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
  • G03G15/0921—Details concerning the magnetic brush roller structure, e.g. magnet configuration
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G2215/00—Apparatus for electrophotographic processes
  • G03G2215/06—Developing structures, details
  • G03G2215/0602—Developer
  • G03G2215/0604—Developer solid type
  • G03G2215/0607—Developer solid type two-component
  • G03G2215/0609—Developer solid type two-component magnetic brush

Definitions

• This invention relates generally to an electrophotographic printing machine, and more particularly concerns an apparatus for dispensing magnetic developer containing marking particles onto a developer roller of a magnetic brush development system.
• the process of electrophotographic printing includes charging a photoconductive member to a substantially uniform potential to sensitize the surface thereof.
• the charged portion of the photoconductive surface is imagewise exposed to light to discharge selected portions of the charged photoconductive surface and create an electrostatic latent image on the photoconductive surface.
• the latent image is developed by bringing developer material into contact therewith.
• Two-component developer material comprises toner particles adhering triboelectrically to carrier granules.
• the carrier particles are usually magnetic.
• the toner particles are attracted from the carrier granules to form a powder image on the photoconductive member.
• the powder image is subsequently transferred to a receiver and heated to permanently affix the powder image to the receiver.
• a magnetic brush development station that includes a reservoir of developer material.
• a transport mechanism brings the developer material into the field of a plurality of magnets within a sleeve (commonly referred to as a developer roller, toning roller, or magnetic brush).
• the transport mechanism includes a transport roller (also known as a feed roller) located between the reservoir and the developer roller.
• the transport roller includes a rotatable, non-magnetic tubular member and a magnet or magnets fixedly disposed interiorly of tubular member to attract the developer material from the reservoir to the transport roller using the force on the developer resulting from the magnetic field of the magnets inside the transport roller.
• the magnets of the transport roller included three alternating magnetic poles in the region of the transport roller adjacent to the reservoir, and the magnetic flux lines from the North to the South poles attracted the developer material to the transport roller.
• the design was changed to include four alternating magnetic poles in the region of the transport roller adjacent to the reservoir, and the magnetic pull was sufficient for commercial use.
• a development station for a reproduction apparatus that includes a housing forming a reservoir, a developer roller for delivering developer material to a development zone, and a transport roller for moving developer material from said reservoir to said developer roller.
• the transport roller includes a rotating shell and a stationary core having an odd number of alternating North and South magnetic poles, wherein the number of magnetic poles is at least five. In one preferred embodiment of the present invention, the transport roller consists of five alternating North and South magnetic poles.
• FIG. 1 is an end view, partly in cross-section, of a reproduction apparatus magnetic brush development station
• FIG. 2 is an end cross-sectional view of a transport roller according to the prior art.
• FIG. 3 is an end cross-sectional view of a transport roller according to the present invention. DETAILED DESCRIPTION OF THE INVENTION
• FIG. 1 A first figure.
• FIG. 1 shows a reproduction apparatus magnetic brush development station 10 that includes a housing 12 forming, in part, a reservoir for developer material.
• Development station housing 12 is locatable in a reproduction apparatus in operative association with a dielectric support member DSM adapted to carry latent image charge patterns, and have developer material images formed of such latent image charge patterns, which are thereafter transferred to receiver sheets to form desired reproductions.
• the housing forming, at least in part, a reservoir for developer material, a photoconductor, a magnetic brush contacting the photoconductor, where the magnetic brush includes a mixture of toner and magnetic carriers and has a magnetic core within a shell having a center of rotation, and said magnetic core is offset relative to said center of rotation toward said drum photoconductor. Since this arrangement is well known in the art, the overall reproduction apparatus is not shown in the accompanying drawings.
• the developer material may be single- component or two-component, but in this illustrative embodiment, it is two- component.
• a plurality of augers 28 are provided, and have suitable mixing paddles for stirring the developer material within a reservoir 12a of housing 12.
• core magnet 16 and shell 18 can have any other suitable relative rotation, which causes developer material to be transported to a development zone 20 into operative association with dielectric support member DSM to develop latent image charge patterns thereon.
• a quantity of developer material is delivered by a transport roller 30 from the reservoir portion of housing 12 to developer roller 14.
• the amount of developer material delivered to development zone 20 is controlled by a metering skive 22 positioned parallel to the longitudinal axis of developer roller 14, at a location upstream in the direction of shell rotation prior to development zone 20.
• a metering skive 22 positioned parallel to the longitudinal axis of developer roller 14, at a location upstream in the direction of shell rotation prior to development zone 20.
• the metering skive 22 is supported on a member mounted for movement perpendicular to the longitudinal axis of developer roller 14.
• the support for metering skive 22 is provided by a plurality of guide pins 31 spaced along the length of the metering skive and are respectively received within a plurality of bores 32
• a conventional transport roller 30 is shown in FIG. 2 and includes a non-magnetic tubular member 34 having a roughened exterior circumferential surface.
• Tubular member 34 is mounted rotatably on suitable bearings.
• a motor (not shown) rotates tubular member 34.
• a magnet core 36 is disposed interiorly of tubular member 34.
• Magnet core 36 is mounted fixedly with a four alternating magnetic poles positioned in the region of the transport roller adjacent to the reservoir 12a.
• the magnetic flux fields associated with the four magnetic poles denoted by reference numerals 40, 41, 42 and 43 set up flux fields 44, 45, 46 and 47.
• the strong magnetic forces of flux fields 44, 45 and 46 beneficially attract the developer material from reservoir 12a onto the transport roller.
• transport roller 60 includes a non-magnetic tubular member 64 having a roughened exterior circumferential surface.
• Tubular member 64 is mounted rotatably on suitable bearings.
• a motor (not shown) rotates tubular member 64.
• a magnet core 66 is disposed interiorly of tubular member 64.
• Magnet core 66 is mounted fixedly with five alternating magnetic poles 50, 51, 52, 53 and 54 positioned in the region of the transport roller adjacent to reservoir 12a.
• the magnetic flux fields associated with the five magnetic poles are denoted by reference numerals, which set up four flux fields 55, 56, 57 and 58.
• the strong magnetic forces of flux fields 55, 56, 57 and 58 beneficially attract the developer material from reservoir 12a onto the transport roller.
• the illustrative embodiment includes fiv ⁇ alternating magnetic poles in the region of the transport roller adjacent to the reservoir, the benefits obtained by present invention are extendable to any odd number of magnetic poles greater than three. Three magnetic poles are not considered to be useful because three poles do not exhibit sufficient magnetism to pull enough developer material from reservoir 12a.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Magnetic Brush Developing In Electrophotography (AREA)
• Dry Development In Electrophotography (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=39203252

Family Applications (1)

Country Status (4)

Families Citing this family (3)

Citations (8)

Family Cites Families (2)

• 2006
  • 2006-11-10 US US11/558,562 patent/US20080112732A1/en not_active Abandoned
• 2007
  • 2007-11-09 JP JP2009536311A patent/JP2010509642A/ja active Pending
  • 2007-11-09 EP EP07861893A patent/EP2080065A1/en not_active Withdrawn
  • 2007-11-09 WO PCT/US2007/023630 patent/WO2008060456A1/en not_active Ceased

Patent Citations (8)

Also Published As

Similar Documents

Legal Events