EP0267787B1 - Revêtement diélectrique pour élément d'enregistrement - Google Patents

Revêtement diélectrique pour élément d'enregistrement Download PDF

Info

Publication number
EP0267787B1
EP0267787B1 EP19870309968 EP87309968A EP0267787B1 EP 0267787 B1 EP0267787 B1 EP 0267787B1 EP 19870309968 EP19870309968 EP 19870309968 EP 87309968 A EP87309968 A EP 87309968A EP 0267787 B1 EP0267787 B1 EP 0267787B1
Authority
EP
European Patent Office
Prior art keywords
recording member
recording
dielectric coating
toner
member according
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
EP19870309968
Other languages
German (de)
English (en)
Other versions
EP0267787A2 (fr
EP0267787A3 (en
Inventor
Vincent K. C/O Minnesota Mining And Rasbury
Charles K. C/O Minnesota Mining And Nordeen
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.)
3M Co
Original Assignee
Minnesota Mining and Manufacturing Co
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 Minnesota Mining and Manufacturing Co filed Critical Minnesota Mining and Manufacturing Co
Publication of EP0267787A2 publication Critical patent/EP0267787A2/fr
Publication of EP0267787A3 publication Critical patent/EP0267787A3/en
Application granted granted Critical
Publication of EP0267787B1 publication Critical patent/EP0267787B1/fr
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
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/0202—Dielectric layers for electrography

Definitions

  • the present invention relates to a recording member for the electrographic recording of toner images thereon and to a coating for the recording member, which coating provides the member with electrical, optical, and durability characteristics useful for the recording process.
  • U.S. Patent No. 3,816,840 discloses an electrographic recording process and apparatus in which a dielectric recording member is arranged between two electrodes. Magnetically adhered to one of the electrodes is electronically conductive toner powder. The toner powder provides an electrically conductive path between the electrode to which it is bound and the adjacent surface of the dielectric member. A voltage is applied to the electrodes for a time and of a magnitude sufficient to generate a force pattern on the toner which enables toner deposition on the recording member in accordance with the force pattern. The force pattern is generated directly on the toner rather than on the recording member, which is passive in the operation of the apparatus disclosed in the patent.
  • Resistance to mechanical damage, abrasion, and wear are important characteristics for the receptor surface of a recording member employed in a process where an appreciable number of images are required to be applied thereto and removed therefrom. These characteristics of durability can be judged by subjecting a receptor surface to repeated cycles of the process and observing the images produced for signs of catastrophic failure or gradual deterioration. The number of cycles completed while retaining the ability to produce images meeting the acceptance criteria is a measure of the surface's durability.
  • the toner it is often desirable to apply the toner to a dielectric recording member which has a background color which offers high contrast to the toner powder.
  • the contrast between toner powder and the recording member to which it is applied were sufficiently high, e.g. 0.6 optical density units, the recorded information could be read directly or indirectly, or even copied by optical means, all with high fidelity and high resolution.
  • the untransferred, unfixed toner powder could be removed from the recording member and new information could be displayed thereon.
  • a system employing a recyclable toner powder could then be designed to optimize the quality of the displayed image without regard to its transfer and fixing properties, or to the cost of depleting the toner powder with each copy.
  • the toner powder could be fixed to the recording member if so desired.
  • Anodized aluminum has been used as a recording member for the electrographic recording apparatus described herein.
  • An aluminum oxide surface that has the appropriate electrical response can be formed on an aluminum substrate by anodization or other conventional means.
  • anodization or other conventional means it is well known that such surfaces change over time, particularly when subjected to environments having high relative humidity. This change may adversely affect the electrical characteristics of the aluminum oxide surface.
  • aluminum oxide surfaces tend to collect a film of moisture that must be removed by special means to assure a stable electrographic process.
  • anodized aluminum and other such surfaces do not have the optical properties desirable for certain desirable applications of the process disclosed in the Kotz patent.
  • a polyester film bearing an appropriate pigment can provide the desired contrast between recording member and toner powder.
  • a polyester film, or a film prepared from another dielectric organic resin when applied to a conductive grounding surface, will generally allow charge to build up resulting in excessive backgrounding and ghosting.
  • FR-A-2,319,927 discloses an electrostatic recording material comprising a non-electrophotoconductive dielectric film layer comprising a hydrophobic pigment in an aqueous dispersion of a defined copolymer coated on the surface of an electrically conductive support.
  • the electrostatic recording material is for use in a system wherein the latent image of an electrical signal formed in the recording layer is developed using a toner.
  • the conductivity of the base layer is such as to produce a superficial resistivity higher than 105 ohms. Build-up of charge in the recording material is desirable and thus the recording material disclosed in FR-A-2,319,927 is not suitable for the Kotz process and apparatus.
  • a recording member suitable for use in an electrographic recording system for recording toner images on a recording member, said system including first and second opposed electrodes spaced apart to define a recording region therebetween, means for driving the recording member through said recording region, and a means for transporting electrically conductive toner powder from a toner reservoir to said recording region to selectively deposit on said recording member in response to the selective application of voltage pulses across electrodes, said recording member comprising a conductive substrate bearing a dielectric coating comprising a polymeric material containing hydrophobic silica therein in an amount sufficient to develop triboelectric charge to interfere with the build-up of charge in the dielectric coating, said amount comprising from about 30% up to about 95% by weight of the dielectric coating, said dielectric coating having a thickness ranging from about 0.05 to about 5.0 micrometers, and said conductive substrate having a resistance of less than 5000 ohms per square.
  • the incorporation of a charge build-up inhibitor in the insulating polymeric material allows the use of the dielectric coating in excess of 100,000 cycles of the image-formation and image-removal process with virtually no build-up of charge or deterioration of image quality.
  • the conductive substrate can be formed of any conductive material, e.g. metals, photoconductive materials.
  • the surface of the dielectric coating is sufficiently durable to allow the recording member to be used repeatedly before it needs to be replaced, e.g. the coating is able to withstand at least 100,000 cycles of image formation with toner powder and removal thereof.
  • the dielectric coating preferably provides high contrast between toner powder and the recording member, e.g. at least 0.6 optical density units, thus allowing an image formed by said toner powder particles to be read and/or copied by optical means, e.g., cameras, photocells, projection onto a recording surface, while retaining high fidelity and high resolution on the reading surface and/or on copies prepared therefrom.
  • FIG. 1 is a schematic view of one embodiment of the recording member of the present invention.
  • FIG. 2 is a schematic view of another embodiment of the recording member of the present invention.
  • FIG. 3 is an end view of an electrographic recording system incorporating the recording member of the present invention.
  • FIG. 4 is a schematic view of an apparatus that can be used to test dielectric materials to determine their suitability for the present invention.
  • FIGS 1 and 2 show alternate embodiments of the recording member of the present invention.
  • the recording system 1 includes a cylindrical developer roll 3 and a rotatable recording member 20.
  • the developer roll 3 preferably is of the type such as disclosed in Anderson, U.S. Pat. No. 3,455,276, and has an inner magnet assembly 5 and an outer cyclindrical shell 6 that is electrically nonconductive and nonmagnetic.
  • the magnetic assembly 5 includes a cylindrical, magnet support core 7 and a plurality of permanent magnet sectors 8 arranged about the cylindrical periphery of the core 7 to define a surface having alternate North and South magnetic poles.
  • the developer roll 3 is mounted on an axle 9 and is constructed such that the magnet assembly 5 rotates in a clockwise direction, whereas the outer shell 6 is spaced from the magnet assembly 5 and is preferably fixed in position.
  • a plurality of individual, spaced apart recording electrodes 10 Arranged on a line that extends parallel with the support core 7 are a plurality of individual, spaced apart recording electrodes 10 (only one of which is shown) that protrude from the periphery of the shell 6, but may also be disposed in the shell 6 so that the outer ends of the electrodes 10 are flush with the periphery of the shell 6.
  • Each electrode 10 is magnetically permeable and passes a large amount of magnetic flux emanating from the magnet sectors 8 of the developer roll 3 so that the developer roll 3 serves as a force means for providing a relatively high magnetic flux density at the outer ends of the electrodes 10.
  • a voltage source 11 supplies record voltage potential pulses to the electrodes 10 in a manner and for a purpose as will be described below.
  • the recording member 20 is mounted on an axle 12 that is parallel to the developer roll 3 and is rotatably driven clockwise to rotate in the same direction as the developer roll magnet assembly 5.
  • the member 20 is positioned in a spaced relationship with the electrodes 10 to define a narrow recording region 13 therebetween.
  • Forming the member 20 are an electrically conductive cylindrical electrode 21 and an endless dielectric coating 22 that overlies the cylindrical surface of the electrode 21.
  • the electrode 21 is electrically grounded.
  • the voltage source 11 serves to provide voltage record pulses to the electrodes 10 to produce a potential difference between the electrodes 10 and the grounded electrode 13. Such potential difference results in toner deposition on the dielectric coating 22.
  • the electrodes 10 are selectively pulsed by the source 11 to form toner images on the surface of the coating 22.
  • the portion of the toner 14 that is deposited on the coating 22 in the form of toner images initially has a relatively high charge and is held on the coating 22 by the potential difference between the charged toner 14 and the grounded electrode 21.
  • the toner is preferably magnetically attractable and electronically conductive.
  • a toner suitable for the apparatus described is disclosed in Nelson, U.S. Pat. No. 3,639,245.
  • a layer of magnetically attractable, electronically conducting toner 14 is metered onto the surface of electrode 10 by a doctor blade 23 which is extended in an axial direction but at a fixed space from electrode 10.
  • the toner 14 is held and attracted to electrode 10 by the magnetic field exerted by magnet sectors 8.
  • the electronic properties of the recording member affect the performance of the electrographic recording system described in the Kotz patent, and the limits placed on these properties depend on the specific embodiment. However, the limits in most cases arise from the following considerations.
  • the resistivity of the recording member should be sufficiently high to prevent so much charge from flowing off of the toner into the recording member at such a rate as to reduce the electrical force to a level insufficient to overcome the magnetic force in image areas.
  • its resistivity should be at least 10 times the resistivity of the toner at electric fields comparable to those experienced by the materials in the practice of the invention of U.S. Patent No. 3,816,840, incorporated herein by reference.
  • the value of resistivity can be determined with an ohmmeter wherein the ohmmeter is connected to two copper bars, both of which bars are placed in contact with the dielectric surface of the recording member.
  • the dielectric coating should be sufficiently thick to withstand the voltages applied during the process.
  • a suitable thickness is at least 5 x 10 ⁇ 6 centimeters (500 Angstroms). The thicker the dielectric coating is above the minimum thickness, the greater the voltage necessary to produce a given force for the same dielectric constant. In general, for practical reasons, the thickness of the dielectric coating is kept to a minimum above that at which electrical breakdown would occur, because thicker dielectric coatings result in reduced resolution of the developed pattern.
  • a sufficient amount of charge build-up inhibitor must be incorporated into the dielectric coating so as to inhibit excessive charge build-up therein.
  • the charge build-up inhibitor interferes with charge build-up by means of a triboelectric effect.
  • hydrophobic silicas function as excellent charge build-up inhibitors. It is preferred to use a high level of hydrophobic silica in the dielectric coating. For example, from about 30 to about 95% by weight of total solid material of the dielectric coating can be hydrophobic silica. Preferably the level of hydrophobic silica is from about 50 to about 75% by weight of total solid material of the dielectric coating. The remainder of the solid material of the dielectric coating generally consists of polymeric material.
  • the coating thickness can range from about 0.05 to about 5.0 micrometers, preferably from about 0.3 to about 2.0 micrometers. Coatings having a thickness far in excess of 2.0 micrometers tend to exhibit poorer image resolution or background deposition of toner powder or to require undesirably high voltages, while coatings having a thickness far below 0.3 micrometers not only tend to lack sufficient durability for a recording member employed in a cyclic electrographic recording process wherein the surface is subjected to repetitive formation and removal of images, but also tend to result in formation of poor images.
  • Typical ranges for parameters for dielectric coatings suitable for the present invention are as follows:
  • a dielectric coating will exhibit the required level of durability if it exceeds 20,000 cycles of image formation and removal, preferably 100,000 cycles of image formation and removal before the coating has been sufficiently eroded to adversely affect the performance of the recording member.
  • certain users of the recording member of this invention will not require a dielectric coating exhibiting even the lower level of durability.
  • the dielectric coating is preferably sufficiently low in reflection optical density so that sufficient contrast between the recording member and toner powder is assured.
  • a suitable level of contrast is, for example, at least +0.6 optical density units. If the coating is transparent, the level of contrast between the toner powder and the material comprising the conductive substrate is, for example, at least +0.6 optical density units.
  • Polymeric materials that are suitable for preparing the dielectric coating of this invention are selected on the basis of the requirements of the specific application in which this recording member is to be used. Generally, the chief requirement is that the charge build-up inhibitor must readily disperse in the polymer/solvent system, if a solvent is used to apply the polymer to the conductive layer, or the polymer itself, if no solvent is used. Other consideration include adhesion to the conductive layer, color or transparency, durability, tolerance of humidity extremes, and ease of handling.
  • polymer classes that are useful include acrylic, polyester, polycarbonate, polyvinyl acetate, polyvinyl chloride, polyvinyl butyral, cellulose acetate, polyvinyl alcohol, polyacrylonitrile, epoxy resins, polyamide, polyvinylpyrrolidone, polyvinyl acetal, cellulose acetate butyrate, polystyrene/butadiene, polyimide, and ethyl cellulose.
  • a convenient test has been developed to determine whether a given material is suitable as a charge build-up inhibitor.
  • the apparatus for conducting this test is shown in FIG. 4.
  • a sample of the material for the dielectric coating 30 is mounted so that it can be moved in close proximity by an electrically grounded toner station 32.
  • the rubbing of the toner 34 against the dielectric material 30 may produce an electrical charge on the dielectric material due to triboelectrification.
  • the magnitude and polarity of this charge is monitored and recorded. It is preferred to provide the sample as a layer of dielectric material in belt form.
  • the belt is placed over a set of rollers 36, 38, one of which is placed in close proximity to the toner station 32. Electrical contact 40 to a conductive layer beneath the layer of dielectric material must be provided and the conductive layer held at ground potential.
  • the magnitude and polarity of any electrical charge on the layer of dielectric material 30 can be detected by using an electrostatic voltmeter 41, such as is manufactured by the Monroe Electronics Co.
  • the dielectric material is passed by the moving toner station 32 for several revolutions, e.g. about 10 to about 100, and the electrical potential recorded.
  • the toner station 32 consists of a magnet roller 42 which is fixed so as not to rotate and an electrically conductive shell 44 which is mounted so as to rotate. Ideally, one of the magnetic poles 46 should face the nip region 48 formed between the two rollers 38 and 42. An electrical connection 50 to the shell 44 must be supplied so that the shell is held at ground potential. A doctor blade 52 is provided in order to control the thickness of the toner layer on the moving shell. The doctor blade 52 must also be held at ground potential. Typical values for the toner station are:
  • the potential of the dielectric material will initially rise (either positively or negatively) from its initial ground potential and then stabilize. Toner may adhere to the surface of the dielectric material as the potential rises. Toner adherence is due to an image force on the toner caused by the accumulation of charge on the dielectric material.
  • the value of the charge on the dielectric material alone may be measured by blowing the toner off of the dielectric layer by means of compressed air or Freon R gas. The magnitude of charge build-up will depend on the relative humidity and should therefore be controlled.
  • a material will be successful as a charge build-up inhibitor if the magnitude of the charge measured in the above manner is from about one to about ten volts. It is important to note that the material under study will only be successful as a charge build-up inhibitor if the stylus printing polarity is opposite that which was measured in the above test. If the polarity of the stylus printing voltage is the same as that measured in this test, the excessive backgrounding and/or ghost images will result.
  • charge build-up inhibitors that are suitable for the recording member of this invention include hydrophobic silica. Hydrophilic silica is not useful for the present invention.
  • the conductive substrate can be formed of either a self-supporting conductive material or a layer of conductive material applied to a non-conductive supporting substrate such as, for example, a flexible belt made of a polymeric material, in which case, the recording member itself would be flexible.
  • a self-supporting conductive material as shown in FIG. 1, the conductive substrate can be a metal drum made of brass, aluminum, steel, or the like, having sufficient conductivity to fulfill the requirements of the electrical circuit of the recording system.
  • the conductive substrate is in contact with ground to create a potential difference between the surface and ground plane.
  • a layer of conductive material can be applied to the surface of non-conductive supporting substrate, e.g. a polymeric film, in which case, the conductive layer occupies an intermediate position between the polymeric film and the dielectric coating. This embodiment is shown in FIG. 2.
  • Materials suitable for the conductive layer include metallic foils or sheets, such as aluminum or copper, metallic coatings such as gold, or metals deposited by one of a number of means such as vapor, sputtering, or plasma deposition, and conductive metal oxide films such as indium tin oxide, which can be deposited by a number of means.
  • the conductive layer is required to exhibit sufficient conductivity so as to transport charge at a rate consistent with the desired application. It has been found that conductive layers exhibiting resistance less than 5000 ohms per square are generally useful in most applications.
  • the conductivity of the conductive layer not decrease below the desired level with time or with exposure of the recording member to changing environmental conditions such as exposure to high or to low relative humidity.
  • the conductive layer should also exhibit the appropriate degree of transparency, reflectivity, or opacity for the desired effect.
  • the recording member When visual display or optical projection of the reflected toner image is contemplated, it is preferred that the recording member produce a non-specular rather than specular reflection. A non-specular background to the image simplifies the arrangement of optical elements used when optical projection is considered.
  • any non-conductive supporting substrate of the recording member be a flexible polymeric film.
  • the film is relatively inexpensive, it is easily coatable, and the resulting product can be converted into various shapes and sizes, e.g. an endless belt for use in an electrographic recording system.
  • the polymeric film can be any material that has sufficient stability to undergo the processing steps required to fabricate the recording member and to function with acceptable durability and stability in the electrographic recording system.
  • polymeric materials suitable for forming the polymeric film are polyesters, polyolefins, polyamides, polyimides and vinyls.
  • Polyester films are preferred because they can be produced with smooth surfaces, are resistant to attack from solvents, are resistant to heat distortion, and have good physical properties such as good tensile strength.
  • Representative examples of commercially available polyester films are various grades of Scotchpar R , manufactured by Minnesota Mining and Manufacturing Company, various grades of Mylar R , manufactured by E. I. DuPont de Nemours Corporation, and various grades of Melinex R , manufactured by ICI.
  • the resin was introduced into the solvent mixture, and the mixture was stirred until the resin was dissolved.
  • the silica was then added to the mixture and dispersed by appropriate means, e.g. high frequency dispersion equipment, such as the "Super Dispax” disperser, available from Tekmar.
  • Example 1 was repeated, the only exceptions being (a) one gram of "Acryloid A-21” resin was used instead of two, and (b) four grams of "HDK 2000” hydrophobic silica from Wacker was used instead of three grams of Aerosil R972 hydrophobic silica.
  • the composition of Example 2 was preferred because it allowed a higher loading of silica and a more stable dispersion. Both compositions provided excellent imaging performance in the apparatus previously described over a period comprising 50,000 to 100,000 cycles.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Photoreceptors In Electrophotography (AREA)

Claims (9)

  1. Elément d'enregistrement (20) convenant pour être utilisé dans un système d'enregistrement électrographique servant à enregistrer des images de toner sur un élément d'enregistrement, ledit système comprenant une première (10) et une seconde (21) électrodes, qui se font face et sont espacées de façon à définir entre elles une zone d'enregistrement, des moyens (12) servant à entraîner l'élément d'enregistrement à travers la zone d'enregistrement et un moyen (11) servant à transporter une poudre de toner électriquement conductrice (14) d'un réservoir de toner (23) à la zone d'enregistrement de façon à se déposer d'une manière sélective sur l'élément d'enregistrement sous l'effet de l'application sélective d' impulsions de tension entre les électrodes, l'élément d'enregistrement comprenant un substrat conducteur (21) portant un revêtement diélectrique (22) qui comprend une matière polymère contenant de la silice hydrophobe en une proportion suffisante pour former une charge triboélectrique destinée à s' opposer à la formation de charge dans le revêtement diélectrique, ladite proportion constituant d'environ 30% jusqu'à environ 95 % en poids du revêtement diélectrique, le revêtement diélectrique ayant une épaisseur comprise entre environ 0,05 et environ 5,0 micromètres et le substrat conducteur (21) ayant une résistivité inférieure à 5000 ohms par carré.
  2. Elément d'enregistrement selon la revendication 1, dans lequel l'inhibiteur de formation de charge constitue d'environ 50% jusqu'à environ 75 % en poids du revêtement diélectrique (22).
  3. Elément d'enregistrement selon la revendication 1, dans lequel ledit élément a une densité optique suffisamment faible pour que le contraste entre l'élément d'enregistrement et le toner soit d'au moins 0,6 unité de densité optique.
  4. Elément d'enregistrement selon la revendication 1, dans lequel le substrat conducteur (21) est en un métal conducteur.
  5. Elément d'enregistrement selon la revendication 1, dans lequel le substrat conducteur comprend une couche conductrice portée par un substrat isolant non conducteur (21).
  6. Elément d'enregistrement selon la revendication 1, dans lequel le substrat électriquement conducteur (21) est transparent à l'égard de la lumière visible.
  7. Elément d'enregistrement selon la revendication 1, dans lequel le revêtement diélectrique (22) est transparent à l'égard de la lumière visible.
  8. Elément d'enregistrement selon la revendication 1, dans lequel l'épaisseur du revêtement diélectrique (22) est d'environ 0,3 micromètre à environ 2,0 micromètres.
  9. Elément d'enregistrement selon la revendication 1, dans lequel ledit élément est flexible.
EP19870309968 1986-11-12 1987-11-11 Revêtement diélectrique pour élément d'enregistrement Expired - Lifetime EP0267787B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92965086A 1986-11-12 1986-11-12
US929650 1986-11-12

Publications (3)

Publication Number Publication Date
EP0267787A2 EP0267787A2 (fr) 1988-05-18
EP0267787A3 EP0267787A3 (en) 1990-04-25
EP0267787B1 true EP0267787B1 (fr) 1995-01-25

Family

ID=25458233

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870309968 Expired - Lifetime EP0267787B1 (fr) 1986-11-12 1987-11-11 Revêtement diélectrique pour élément d'enregistrement

Country Status (3)

Country Link
EP (1) EP0267787B1 (fr)
JP (1) JPS63141065A (fr)
DE (1) DE3751026D1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4943819A (en) * 1988-09-20 1990-07-24 Canon Kabushiki Kaisha Image holding member and image forming device
US5162179A (en) * 1990-04-17 1992-11-10 Armstrong World Industries, Inc. Electrographic structure and process

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4917738A (fr) * 1972-06-06 1974-02-16
US3816840A (en) * 1973-04-20 1974-06-11 Minnesota Mining & Mfg Electrographic recording process and apparatus using conductive toner subject to a capacitive force
US3946402A (en) * 1974-05-28 1976-03-23 Minnesota Mining & Manufacturing Company Toner applicator for electrographic recording system
JPS52131722A (en) * 1975-07-28 1977-11-04 Japan Synthetic Rubber Co Ltd Method of manufacturing electrostatic recording medium
US4402000A (en) * 1979-03-22 1983-08-30 Minnesota Mining And Manufacturing Company Electrographic recording method and apparatus with control of toner quantity at recording region
JPS6057346A (ja) * 1983-09-08 1985-04-03 Canon Inc 像保持部材

Also Published As

Publication number Publication date
EP0267787A2 (fr) 1988-05-18
JPS63141065A (ja) 1988-06-13
EP0267787A3 (en) 1990-04-25
DE3751026D1 (de) 1995-03-09

Similar Documents

Publication Publication Date Title
US5187496A (en) Flexible electrographic imaging member
US5659852A (en) Image forming method, image forming apparatus and process cartridge
JP2001183893A (ja) カラー画像形成装置
US4410584A (en) Electrostatic recording member
US6463246B1 (en) Developer, development method, development device and its elements, and image-forming device
EP0267787B1 (fr) Revêtement diélectrique pour élément d'enregistrement
US5774769A (en) Charging apparatus and image forming apparatus
EP0709746B1 (fr) Méthode et appareil de formation d'images, cassette de traitement et utilisation de materiau développateur pour ladite méthode
US5064715A (en) Dielectric coating for recording member containing hydrophobic silica
US5799233A (en) Charging apparatus and image forming apparatus
EP0576893A1 (fr) Révélateur pour le développement d'images latentes électrostatiques et procédé de formation d'images utilisant celui-ci
EP0247735B1 (fr) Couche diélectrique pour un membre d'enregistrement
US4120720A (en) Combined means for accurately positioning electrostatographic recording members during imaging and means for establishing electrical connection with the intermediate conductive layer thereof
US4404574A (en) Electrographic printing system using dielectric film member
US4666780A (en) Dielectric coating for recording member
JP2701848B2 (ja) 現像方法
US5327200A (en) Transfer sheet-carrying member and image forming apparatus
US4112172A (en) Dielectric imaging member
US4943819A (en) Image holding member and image forming device
US5981120A (en) Verdefilm for more uniform charging
US5258782A (en) Device for removing charge from a dielectric member in an image forming apparatus
JP2894508B2 (ja) 帯電用部材
JP3296536B2 (ja) 帯電装置及び電子写真装置
JPH0273275A (ja) 画像形成装置
EP0864937A1 (fr) Appareil de formation d'images

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19901002

17Q First examination report despatched

Effective date: 19920715

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

ITF It: translation for a ep patent filed
AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19950125

REF Corresponds to:

Ref document number: 3751026

Country of ref document: DE

Date of ref document: 19950309

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19950426

EN Fr: translation not filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19951111

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19951111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051111