US3611991A - Vibrating bed developing apparatus with electromagnetic developer agitator - Google Patents

Vibrating bed developing apparatus with electromagnetic developer agitator Download PDF

Info

Publication number
US3611991A
US3611991A US854838A US3611991DA US3611991A US 3611991 A US3611991 A US 3611991A US 854838 A US854838 A US 854838A US 3611991D A US3611991D A US 3611991DA US 3611991 A US3611991 A US 3611991A
Authority
US
United States
Prior art keywords
developer
developer material
support medium
movement
reservoir
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
US854838A
Other languages
English (en)
Inventor
Eugene F Young
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
Application granted granted Critical
Publication of US3611991A publication Critical patent/US3611991A/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
    • G03G15/06—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 Apparatus for developing electrostatic latent images carried by a support medium with a vibrating bed of two-component magnetizable developer material.
  • the development unit includes a housing, containing developer material, positioned adjacent a latent image-bearing support medium and vibrated to convey the developer material into contact with the latent image for effecting the development thereof.
  • a plurality of electromagnets are carried by the inner peripheral surface of the developer housing and sequentially actuated to, in combination with the vibratory movement cf fect intermixing of the developer material.
  • This invention relates in general to the development of electrostatic latent images on a support medium and, in particular, to eliminating development defects in a developing apparatus utilizing vibrational forces to apply developer material to the latent image.
  • this invention relates to a vibrating bed developing apparatus having a plurality of electromagnets which are sequentially actuated to, in combination with the vibratory forces, effect the intermixing of the developer material within the developer housing to eliminate development defects resulting from localized developer conditions.
  • developer material which generally comprises a mixture of suitable pigmented or dyed resin-based powder (referred to as toner) and a carrier material, which functions to generate triboelectric charges on and to carry the toner, is applied to the latent image to render it visible.
  • the developer material is brought into surface contact with the electrostatic latent image to render it visible.
  • the developer material is brought into surface contact with the electrostatic latent image and the toner powder, for example of the type disclosed in Carlson U.S. Pat. No. 2,940,934,is removed from the carrier material and attracted to the latent image in a pattern corresponding to the electrical charges.
  • the developed toner powder image may be transferred to a support medium to which it may be permanently fixed or it may be fixed to the original electrostatic latent image bearing surface depending upon the particular electrostatographic imaging process utilized, as is well known in the art.
  • One method of developing electrostatic latent images is referred to in the art as vibrating of fluidized bed development.
  • a quantity of two-component developer material is vibrated beneath the latent electrostatic image so rapidly that the developer material is suspended in a fluidized mass or bed.
  • the image is contacted by the vibrating or constantly moving developing to effect development of the latent images.
  • Various fluidized or vibrating bed development techniques have been disclosed, for example, in US. Pat. Nos.
  • Striations which are caused by an uneven contacting of the image-bearing surface by the developer material, occur most predominantly in fluidized bed development systems which vibrate the developing material in the direction of the image movement. These striations are caused by the slapping effect that waves of fluidized developer material have on the imagebcuring surface. As an image-bearing surface is moved through the vibrating developer, it is rhythmically contacted by these fluidized bed developer waves. This periodic contact of these latent image-bearing surface by the developer material creates an uneven developer presentation to the image which causes image striations.
  • Tracking, or unwanted developer streaks in the direction of movement of the latent image occurs when a quantity of developer material includes a mass of undertoned carrier particles or carrier particles which have been depleted of toner such that the mass of carrier is presented along one line of the latent image-bearing surface until it is replaced by properly toned carrier flowing through the developer zone. If the developer material and latent image bearing surface move in a straight line relative to each other, the improperly developed image portion will be extended over a straight line the length of the latent image area.
  • the mixture As toner powder is added to the developer mixture, the mixture must be throughly intermixed to create the desired triboelectric relationship between the toner powder and the carrier material. This maintenance of the proper triboelectric relationship between the materials of the developer mixture becomes increasingly important when the movement of the developer material is limited as in a vibrating bad-developing system. Therefore, it becomes necessary for the cross-mixing and intermixing of the developer material to eliminate development defects characteristic of localized developer conditions such as occurs when a multiple number of copies are reproduced from a single original. If the developer mixture is not intermixed, developer material in certain areas will have a high concentration of toner powder than other areas resulting in a nonuniform toner powder image.
  • Another object of this invention is to increase the intermixing and cross-mixing of developer material in a vibrating bed developing apparatus.
  • a further object of this invention is to eliminate development defects characteristic of localized developer conditions.
  • Still another object of this invention is to utilize the vibratory forces of a vibrating bed developing system to minimize the external forces required to intermix the developer material.
  • a vibrating bed developing system utilizing a two-component magnetizable developer material wherein the vibrational force is applied so rapidly that the mass of developing material will be suspended to contact and develop images on the surface.
  • a plurality of sequentially actuated electromagnets are positioned about the inner peripheral surface of the vibrating bed developing unit to, in combination with the vibrational forces, intermix the developing material contained in the developer housing.
  • FIG. I is a mechanical schematic representation of an automatic xerographic reproducing machine utilizing the invention of this application;
  • FIG. 2 is a front perspective view of a vibrating bed development apparatus to better illustrate the positioning of the electromagnets within the developer housing;
  • FIG. 3 is an electrical-mechanical schematic of the electromagnetic development intermixing system.
  • FIG. 11 there is illustrated a mechanical schematic of an automatic xerographic reproducing apparatus embodying the present invention.
  • the elements of this machine are all well known in the electrostatographic art with the exception of the development station which forms the basis of the present invention.
  • the vibratory movement of the developer mechanism 410 is described as transverse to the movement of the electrostatic latent image-bearing support surface. However, it is not intended to be so limited but may be utilized wherein the vibratory movement is radial or parallel to the movement of the latent image bearing surface, or any other such vibratory movement.
  • An electrical charge pattern is formed on the surface of the drum 1 by any suitable technique, for example, as illustrated in FIG. I by charging and exposing a photoconductive surface.
  • the latent image is subsequently rendered visible at a developing station 41 and then may be transferred 5 to a suitable support medium 6 to which it is permanently affixed or the image may be permanently affixed to the image support surface depending upon the type of photoreceptor used as is well known in the electrostatographic art.
  • the developing apparatus shown in FIG. 1 is constructed in two major sections, a developer vibrating or developing assembly 40 and the developer recirculation assembly 80.
  • the purpose of the developer vibrating assembly is to impart vibratory motion to magnetizable two-component developer material adjacent the electrostatic latent image bearing surface.
  • the developer recirculation assembly is to move developer to the input of the developer vibrating elements and returned to the sump portion 81 of the developing apparatus.
  • the developer vibrating assembly, 40 comprises an arcuate plate 41 positioned concentric with the photoreceptor and spaced therefrom to rapidly vibrate the developer material against the electrostatic latent image.
  • the opposite ends of the arcuate plate 41 are secured by suitable means to a mounting plate 42 positioned adjacent the opposite end faces of the drum.
  • the mounting plates are provided at each end with suitable guide pins 43 and apertures 14 which restrain the arcuate plate and the rest of the vibratory elements for movement in a purely reciprocatory longitudinal path.
  • a screen 50 is secured concentric with and between the drum 1 and arcuate plate 41 for aiding in vibrating the developer material.
  • the screen is grounded or provided with an electrical bias from any suitable source of potential to thus create an electric field adjacent the image and is suitably electrically isolated from the plate 51 by suitable insulation.
  • a plate 60 with a J-shaped cross section is also secured at its opposite end between the mounting plates &2.
  • the plate 60 is thus vibrated with the arcuate plate 41 and screen 50 during operation for maintaining the developer in a fluidized state.
  • the developer thus exhibits a movement down the longer leg 61 of the plate 60 toward the developer recirculation assembly 80 after reversing direction at the curved portion 62.
  • the developer recirculation assembly 80 is similar to the conventional unit employed to convey developer material from the sump portion of a cascade development unit to introduce the material to the latent image.
  • a bucket conveyor assembly b5 comprising a plurality of buckets 86 supported on a flexible endless belt 87 is held in position by two suitably driven rollers 88 and 89.
  • the conveying assembly circulates developer material from the sump 81 to be introduced to the latent image by the vibratory assembly :10.
  • the vibratory mo tion to the developer assembly is imparted by a motor MOT-ll suitably connected to the vibratory mounting plates 42 and coupled whereby the rotary motion of the drive shaft is converted to a reciprocation of the vibratory elements.
  • FIGS. 2 and 3 there is shown a plurality of electromagnets supported along the inner peripheral surface of the developer vibrating assembly and electrically isolated from the developing vibrating assembly and electrically apparatus.
  • the electromagnets are appropriately secured to the mounting plates 42, and front (62) portion of the J-shaped cross section plate 60 having its opposite ends secured between the mounting plates 42.
  • the electromagnets 90 are connected through suitable electrical connections to a commutator COM1 and sequentially actuated by the rotation of the commutator arm 91.
  • the magnetizable developer material is vibrated in a suspended or fluidized mass.
  • the electromagnets 90 are sequentially actuated by the commutator COM-ll such that as the developer material is vibrated in a suspended mass, the developer material is attracted towards the electromagnet which has been actuated by the commutator. In this manner the developer material is attracted in a direction towards the selectively actuated electromagnet and simultaneously applied to the latent electrostatic image.
  • the developer material is caused to flow in a somewhat circular motion thereby intermixing the developer material and eliminating localized development defects as the developer material is simultaneously vibrated and cross-mixed.
  • mixing means supported by said developer supporting surface actuable to effect movement of the magnetizable developer material in a direction independent of the agitating movement of said developer material.
  • electromagnetic means supported by said developer reservoir adapted when actuated to effect an intermixing movement of the suspended fluidized mass of developer material within said reservoir independent from any movement imparted to said developer material by the vibration of said developer reservoir.
  • Apparatus for developing latent electrostatic charge patterns on a support medium including,
  • a developing reservoir in communication with said support medium and containing a quantity of magnetically attractable developer material
  • electromagnetic means supported by said developer reservoir adapted when actuated to effect an intermixing movement of the suspended fluidized mass of developer material within said reservoir independent from any movement imparted to said developer material by said vibrating means.
  • Apparatus for developing latent electrostatic charge patterns on a support medium including;
  • a vibratory developer reservoir in communication with said support medium and containing a quantity of magnetically attractable developer material
  • electromagnetic means supported by said developer reservoir adapted when actuated to elfect an intermixing movement of the suspended fluidized mass of developer material within said developer reservoir independent and exclusive of any movement and agitation imparted to said developer material by said vibrating means, and

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
US854838A 1969-09-03 1969-09-03 Vibrating bed developing apparatus with electromagnetic developer agitator Expired - Lifetime US3611991A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85483869A 1969-09-03 1969-09-03

Publications (1)

Publication Number Publication Date
US3611991A true US3611991A (en) 1971-10-12

Family

ID=25319647

Family Applications (1)

Application Number Title Priority Date Filing Date
US854838A Expired - Lifetime US3611991A (en) 1969-09-03 1969-09-03 Vibrating bed developing apparatus with electromagnetic developer agitator

Country Status (11)

Country Link
US (1) US3611991A (enrdf_load_stackoverflow)
JP (1) JPS4910260B1 (enrdf_load_stackoverflow)
BE (1) BE755605A (enrdf_load_stackoverflow)
CH (1) CH521615A (enrdf_load_stackoverflow)
DE (1) DE2042880A1 (enrdf_load_stackoverflow)
ES (1) ES383333A1 (enrdf_load_stackoverflow)
FR (1) FR2061073A5 (enrdf_load_stackoverflow)
GB (1) GB1264780A (enrdf_load_stackoverflow)
NL (1) NL7012879A (enrdf_load_stackoverflow)
PL (1) PL81279B1 (enrdf_load_stackoverflow)
SE (1) SE361956B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3790397A (en) * 1969-09-15 1974-02-05 Xerox Corp Retoning carrier beads in the development zone
US3962992A (en) * 1973-10-26 1976-06-15 Tokyo Shibaura Electric Co., Ltd. Device for developing an electrostatically charged image
US3973517A (en) * 1975-02-18 1976-08-10 Xerox Corporation Development device and method
US5523824A (en) * 1995-04-26 1996-06-04 Ravi & Associates Switchable self-propelled magnetic brush

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2318571A (en) * 1933-12-22 1943-05-04 Minnesota Mining & Mfg Manufacture of abrasives
US3117891A (en) * 1960-09-26 1964-01-14 Xerox Corp Xerographic apparatus
US3357399A (en) * 1966-07-21 1967-12-12 Xerox Corp Combined fluidized bed and inverted cascade development apparatus
US3484265A (en) * 1966-07-21 1969-12-16 Xerox Corp Transversely reciprocating fluidized bed development method
US3545968A (en) * 1966-12-24 1970-12-08 Fuji Photo Film Co Ltd Developing a latent electrostatic image with ferromagnetic carrier and toner by employing a varying magnetic field

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2318571A (en) * 1933-12-22 1943-05-04 Minnesota Mining & Mfg Manufacture of abrasives
US3117891A (en) * 1960-09-26 1964-01-14 Xerox Corp Xerographic apparatus
US3357399A (en) * 1966-07-21 1967-12-12 Xerox Corp Combined fluidized bed and inverted cascade development apparatus
US3484265A (en) * 1966-07-21 1969-12-16 Xerox Corp Transversely reciprocating fluidized bed development method
US3545968A (en) * 1966-12-24 1970-12-08 Fuji Photo Film Co Ltd Developing a latent electrostatic image with ferromagnetic carrier and toner by employing a varying magnetic field

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3790397A (en) * 1969-09-15 1974-02-05 Xerox Corp Retoning carrier beads in the development zone
US3962992A (en) * 1973-10-26 1976-06-15 Tokyo Shibaura Electric Co., Ltd. Device for developing an electrostatically charged image
US3973517A (en) * 1975-02-18 1976-08-10 Xerox Corporation Development device and method
US5523824A (en) * 1995-04-26 1996-06-04 Ravi & Associates Switchable self-propelled magnetic brush

Also Published As

Publication number Publication date
DE2042880A1 (de) 1971-03-11
BE755605A (fr) 1971-03-02
PL81279B1 (enrdf_load_stackoverflow) 1975-08-30
SE361956B (enrdf_load_stackoverflow) 1973-11-19
FR2061073A5 (enrdf_load_stackoverflow) 1971-06-18
GB1264780A (enrdf_load_stackoverflow) 1972-02-23
JPS4910260B1 (enrdf_load_stackoverflow) 1974-03-09
CH521615A (de) 1972-04-15
ES383333A1 (es) 1973-01-01
NL7012879A (enrdf_load_stackoverflow) 1971-03-05

Similar Documents

Publication Publication Date Title
US3140199A (en) Vibrating belt powder cloud generator for xerography
US3809472A (en) Pre-development exposure assembly
US3638614A (en) Electrostatic latent image development apparatus
US4098228A (en) High speed magnetic brush development system
US3357399A (en) Combined fluidized bed and inverted cascade development apparatus
US3542579A (en) Electrostatic image development
US3393663A (en) Fluidizing electrode development apparatus
US3608522A (en) Xerographic development control apparatus
US3584601A (en) Magnetic brush belt development
US3712266A (en) Developer conveying apparatus
US3380437A (en) Transversely reciprocating fluidized bed development apparatus
US3611991A (en) Vibrating bed developing apparatus with electromagnetic developer agitator
US4139296A (en) Cross mixer
US3484265A (en) Transversely reciprocating fluidized bed development method
US3635196A (en) Pneumatically controlled seal
US3415224A (en) Magnetic cascade development apparatus
US3470009A (en) Powder cloud development of electrostatic images
US3621816A (en) Interlaced vibrating electrode
US3592166A (en) Apparatus for developing electrostatic images
US3754531A (en) Fluidized development apparatus
US3926516A (en) Development apparatus for an electrostatographic printing machine
US3654900A (en) Fluidized development of electrostatic images
US3550555A (en) Xerographic developer separation
US3641977A (en) Apparatus for agitating developer material within a housing
US3670701A (en) Two step orbital pad development