EP0291392B1 - Pulverförmige Substanz zur Reibungsverminderung des Aufnahmeträgers eines magnetischen Druckers - Google Patents

Pulverförmige Substanz zur Reibungsverminderung des Aufnahmeträgers eines magnetischen Druckers Download PDF

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Publication number
EP0291392B1
EP0291392B1 EP19880401089 EP88401089A EP0291392B1 EP 0291392 B1 EP0291392 B1 EP 0291392B1 EP 19880401089 EP19880401089 EP 19880401089 EP 88401089 A EP88401089 A EP 88401089A EP 0291392 B1 EP0291392 B1 EP 0291392B1
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European Patent Office
Prior art keywords
particles
pulverulent
drum
recording medium
filaments
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EP19880401089
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English (en)
French (fr)
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EP0291392A1 (de
Inventor
Bernard Cherbuy
Jacques Estavoyer
Daniel Kinet
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Bull SAS
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Bull SAS
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G19/00—Processes using magnetic patterns; Apparatus therefor, i.e. magnetography
    • 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
    • G03G5/005—Materials for treating the recording members, e.g. for cleaning, reactivating, polishing

Definitions

  • the present invention relates to a pulverulent substance for the lubrication of the recording medium of a magnetic printer.
  • the latent image thus formed is then developed, that is to say made visible, using a powdery developer which, made up of thermoplastic resin particles containing each of the magnetic particles, is only attracted by the magnetized areas of the recording medium and thus forms a powder image on the surface of this medium. After which, this powder image is transferred to the receiving sheet of paper.
  • a recording device which has a plurality of magnetic heads arranged one next to the other.
  • Each of these heads is formed of a metal core, of high magnetic permeability, on which is wound a winding, this core having, at one of its ends, a magnetic pole, called writing or recording, which is placed in contact with or near the magnetic layer, so that each time an electric current of suitable intensity is sent into this winding, this current creates, in the core, a magnetic flux which has the effect of magnetizing the portion of the magnetic layer located opposite the writing pole of the head.
  • the magnetized points thus formed by the different heads of the transducer must not only be perfectly delimited and all have substantially the same size, but they must also have practically the same intensity of magnetization, in order to be able to each retain a quantity of developer particles. which remains practically constant from one point to another. To meet these requirements, it is essential that the distance between each head of the magnetic layer remains constant and less than a predetermined limit value.
  • the magnetized points formed on the magnetized layer each have, on the surface of this layer, a square section of the order of a hundred ⁇ m on a side and are distributed at a density such that the distance separating two neighboring magnetized points is practically equal to thirty ⁇ m
  • this limit value has been found equal to ten microns. Adjusting the heads and recording media to keep this distance as constant as possible has It has always been a difficult problem to solve which could only be overcome by using complex and particularly expensive equipment. This is why, in order to avoid using such equipment, it has been practically necessary to bring the heads of the transducer into contact with the magnetic surface of the recording medium. However, bringing the heads into contact with this magnetic surface has the effect of generating, during the movement of the recording medium, overheating all the more important as the driving speed of this medium is higher.
  • These warm-ups are capable of disrupting, or even preventing, the recording of information on the support.
  • they cause the softening of the developer particles which have been deposited on the support, so that these particles cannot be completely transferred to the sheet of paper.
  • a resin film is formed on the magnetic layer of the support, the thickness of which increases with time, this film having the effect of constantly increasing the distance between the recording heads and the magnetic layer, and thus make the printing of the characters totally defective.
  • a lubricant application device for electrophotographic recording media is known from the Japanese Patent Application Publication No. 60.12571.
  • This device comprises a reservoir containing the lubricating substance, and having at its lower part an opening shaped so as to allow all the points on the surface of the recording medium to pass under the opening during the drive of the medium.
  • the present invention overcomes these drawbacks and provides a pulverulent substance which, when applied to the surface of the recording medium of a magnetic printer, provides suitable lubrication of this material. support, without causing an undesirable background on the printed sheet of paper.
  • the present invention relates to a pulverulent lubricating substance capable of being applied to the external surface of a recording medium of a magnetic printer, said substance consisting of particles of a pulverulent insulating material capable of reducing friction between said surface and a recording member applied against this surface, this substance being characterized in that it further contains particles of conductive carbon which are arranged around said insulating particles to form groups of lubricating particles, the mass ratio total of carbon to that of said insulating material being between 0.2 and 1.
  • the present invention also relates to applicator devices, according to claims 5 and 7, which make it possible to deposit on the recording medium of a printer a pulverulent lubricating substance.
  • the printing machine part of which has been shown diagrammatically in FIG. 1, comprises a recording medium which is constituted, in the example described, by a magnetic drum 10.
  • This magnetic drum 10 which is mounted so as to be able to rotate around a horizontal axis 11, is rotated, in the direction indicated by the arrow F, by an electric motor (not shown).
  • the recording of information on this drum is carried out by a magnetic recording member 12 which is kept applied to the external surface 13 of the drum 10 under the action of a spring 14.
  • This recording member 12 is formed, of known manner, of a set of magnetic recording heads which, placed one next to the other, are aligned parallel to the axis of rotation 11 of the drum 10.
  • Each of these heads generates, each time it is excited for a short time by an electric current, a variable magnetic field, which has the effect of creating, on the surface 13 of the drum which passes in front of the recording member 12, magnetized zones 15 practically punctual, the set of these zones constituting a latent magnetic image corresponding to a character to be printed.
  • These magnetized zones 15 then pass in front of a developer applicator device 16 which is arranged below the drum 10 and which makes it possible to apply to the surface 13 of this drum particles of a powdery developer contained in a reservoir 17.
  • This device appplicateur 16 will not be described here for the reason that it is of similar type to that described in french patent application Publication No. 2408462.
  • Developer particles that are applied by this device on the surface 13 of the drum adhere, in principle, only to the magnetized areas of this drum, so that these areas, after passing in front of the applicator device 16, appear coated with a layer of developer, thus forming deposits 18 on the surface 13 of the drum.
  • These deposits 18 then pass in front of a retouching device 19 which has the role of eliminating the developer particles which have adhered elsewhere than to the magnetized zones 15, as well as the particles which are found in excess in these zones.
  • the developer particles which, after passing in front of the retouching device 19, remain on the drum are then transferred, almost entirely, onto a sheet of paper 20 which is applied to the surface 13 of the drum by means of a roller pressure 21.
  • the residual developer particles which, when this transfer is carried out, are still on the drum 10 are then removed by means of a felt pad 28 which, applied to the surface of the drum, is part of a cleaning device 22.
  • the magnetized zones which have passed in front of this cleaning device 22 then pass in front of a lubricant applying device 23 which will be discussed later, then in front of an erasing device 24 which, excited by an alternating electric current, ensures, in a known manner, the erasing of the magnetized zones passing in front of it, the portions of the drum thus demagnetized by this erasing device then being able be magnetized again when they appear before the recording device 12.
  • the powdery developer which is contained in the reservoir 17 of the printing machine shown in FIG. 1 is made up of magnetic particles coated with a thermoplastic resin which, by heating, is capable of melting and fixing on the sheet of paper 20 on which it was filed. This fusion is normally caused by a heating device (not shown) through which the sheet of paper 20 after passing between the drum 10 and the pressure roller 21.
  • the magnetic drum 10 which equips the printing machine shown in Figure 1 is of known structure.
  • This drum 10, a part of which has been shown diagrammatically in FIGS. 3 and 4, is essentially formed of a conductive cylindrical core 25, made for example of brass or mild steel, coated with a layer 26 of magnetic alloy, also conductive, consisting for example of a nickel-cobalt-phosphorus alloy containing approximately 76 to 82% of cobalt and 1 to 2% of phosphorus, this layer having a thickness of between ten and thirty microns about.
  • An intermediate conductive layer 27, intended to play the role of magnetic shunt and consisting of a metal or a magnetically soft alloy such as mild steel, can optionally be interposed between the cylindrical core 25 and the layer 26 of magnetic alloy.
  • the magnetic drum 10 thus formed is, as shown in Figure 1, electrically connected to earth, for reasons which will be indicated later.
  • the recording member 12 which is part of the printer shown in Figure 1 will not be described in detail for the reason that its structure is similar to that which was incidentally disclosed in French Patent No. 2,518,770. It will be recalled, however, that the magnetic heads which equip this recording member are positioned so that the ends of the writing poles of these heads are flush with a sliding face of this member.
  • the erasing device 24 is preferably mounted on an elastic device of known type (not shown) which keeps it constantly pressed against the surface 13 of the drum.
  • This lubricating substance consists of particles of an insulating, pulverulent, dry material, of known type, capable of reducing the friction exerted, during the rotation of the drum 10, by the surfaces of the recording member and of the recording device. 'erasures that are in contact with the surface of this drum.
  • This insulating, lubricating, pulverulent, dry material may consist of disulphide molybdenum or with a metal salt of saturated, unsaturated or partially substituted fatty acid.
  • this metal salt can be derived from one of the fatty acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, l stearic acid, arachidic acid, behenic acid, oenanthylic acid, pelargonic acid, undecylic acid, tridecylic acid, pentadecylic acid, margaric acid, nonadecylic acid, l tricosanic acid, undecylenic acid, oleic acid, linoleic acid, linolenic acid, oleostearic acid, arachidonic acid, petroselinic acid, vaccenic acid, gadoleic acid, l palmitolic acid, ketooleic acid, ricinoleic acid, as well as mixtures of these acids.
  • the fatty acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid,
  • the most suitable metal salts belong to the group comprising barium, calcium, strontium, cadmium, magnesium, zinc, copper, lead, iron, cobalt and nickel stearates, palmitates of calcium, zinc, copper, aluminum, magnesium and cobalt, magnesium, zinc, copper, lead, manganese, iron and cobalt oleates, lead caprylate, lead caproate , calcium, zinc and cobalt linoleates and zinc and cadmium ricinoleates.
  • the insulating, lubricating, dry material can also consist of fine particles of polytetrafluoroethylene.
  • the insulating, lubricating, dry material always has a fine particle size, the size of the particles which constitute this material being in fact of the order of one micron.
  • this pulverulent material is, before being applied to the surface of the drum 10, mixed with very fine particles of conductive carbon, the size of these carbon particles being about a hundred times smaller than that of insulating material particles, that is to say of the order of 0.01 micron.
  • the quantity of pulverulent carbon which is thus added to the insulating, lubricating, pulverulent material is such that the total mass of carbon added remains between 0.2 M and 1 M, M being the mass of lubricating insulating material.
  • the pulverulent lubricating substance which must be applied to the surface of the drum can be obtained, for example, by taking, on the one hand, one hundred grams of pulverulent polytetrafluoroethylene, on the other hand, an amount of powdery conductive carbon between twenty and one hundred grams, and by carefully mixing these two products using a rapid mixer of known type.
  • the pulverulent mixture which is thus obtained consists of groups of particles of the type of those which have been represented and designated by G in FIG. 2, each of these groups being formed, as can be seen in this figure, of a single particle 30 of lubricating insulating material (for example polytetrafluoroethylene) surrounded, on its periphery, of particles 31 of conductive carbon.
  • G lubricating insulating material
  • the particles 30 and 31 have not been shown to scale for obvious reasons of clarity of the drawing.
  • the number of carbon particles 31 which surround the same particle of insulating material 30 depends on the level of carbon contained in the pulverulent lubricating substance, but, if the mixture of lubricating insulating material and of powdery conductive carbon has been carefully produced, this number remains practically constant when moving from one insulating particle to another. It should also be noted, that even in the case where the amount of carbon which is thus added is relatively small, that is to say equal to 0.2 times the mass of the lubricating insulating material, the number of carbon particles 31 which surround the same insulating particle 30 is high enough for these carbon particles, which are regularly distributed over the external surface of this insulating particle, to cover the whole of this surface.
  • the pulverulent lubricating substance which is formed from groups of particles G, the constitution of which has just been indicated in detail above, is regularly distributed over the external surface 13 of the magnetic drum 10 by means of an applicator device 23 which is produced so as to deposit, on this surface, a quantity of lubricating substance which remains between 0.02 and 0.08 milligrams per square meter of surface.
  • this applicator device comprises a reservoir 35 containing the pulverulent lubricating substance.
  • This tank 35 which is shown in Figure 3, in section along a plane perpendicular to the axis of rotation 11 of the drum 10, is placed, as can be seen in Figure 1, above this drum, between the cleaning device 22 and the erasing device 24.
  • This reservoir 35 is formed by two plates 36 and 37, one of which 36, of rectangular shape, is disposed approximately vertically, perpendicular to the cutting plane and so that its lower edge 38 is at a distance of five to ten millimeters from the surface 13 of the drum 10, and the other 37 of which, arranged perpendicular to the cutting plane, is inclined relative to the plate 36, these two plates being joined to each other by two transverse plates, only one of which is visible in FIG. 3, these four plates forming a non-deformable housing, having practically the shape of a prism whose edge is turned downwards .
  • the plate 37 is adjusted so that, on the one hand, the distance which separates its lower edge 40 from the surface 13 of the drum is substantially the same as that which separates this surface from the lower edge 38 of the plate 36 , and that, on the other hand, the spacing between these two lower edges 38 and 40 is at most equal to five millimeters.
  • the reservoir 35 has, at its lower part, a rectangular opening 41 which, located at a short distance from the surface 13 of the drum, extends over a length equal to the length of this drum, the width of this opening being very small compared to its length.
  • the applicator device which is shown in FIG. 3 further comprises a plurality of very flexible filaments 42 which each have one of their ends embedded inside a mass 43 of hardened resin, itself clamped in a stirrup 44 fixed inside the tank 35.
  • These filaments 42 have a length such that they pass through the opening 41 of the tank 35 and come, by their other end, to contact the surface 13 of the drum 10.
  • These filaments which have a diameter of about 0.1 millimeter, are made of a very flexible natural or synthetic material, which allows them, when suspended by one of their ends, to remain approximately in the vertical position or to return to it when, after being removed from this position, they are then released.
  • these filaments can be formed from animal fibers, of the horsehair type for example, carbon fibers, or even from a flexible threadlike plastic material, such as the polyamide material which is sold under the name of " nylon "(registered trademark).
  • the number N of these filaments 42 is such that the latter almost completely obstruct the opening 41 of the reservoir 35. More precisely, if we designate by ⁇ the surface of the cross section formed by this opening in the absence of filaments and by S the total cross-sectional area of these N filaments (the value of S being thus given by the expression: where d represents the diameter of each filament), the number N is such that the ratio S / ⁇ is between 0.35 and 0.8. It follows that the number N of filaments 42 which partially obstruct the opening 41 of the reservoir 35 is between two limit values N m and N M given, respectively, by the expressions:
  • the quantity of lubricating substance which is thus deposited, per unit of surface, on the surface 13 of this drum depends on the number N of filaments 42 which partially obstruct the opening 41 of the reservoir, this quantity being all the greater the lower the number N of these filaments. It was thus found that, in the case where the number of these filaments was equal to the limit value N m indicated above, the quantity of lubricating substance which was deposited, per square meter, on the surface of the drum was practically equal to 0 0.05 mg, whereas, in the case where the number of these filaments was equal to the limit value N M indicated above, the quantity of lubricating substance deposited, per square meter, on the drum was practically equal to 0.02 mg .
  • the device for applying the lubricating substance which has just been described is placed between the cleaning device 22 and the erasing device 24, that is to say say upstream of this erasing device, the particles which are thus deposited by this applicator device on the surface 13 of the drum allow this surface to be lubricated just before it passes under this erasing device 24 and under the recording device 12.
  • the lubricant applicator device comprises a chamber 59, which is situated above the surface 13 of the drum, and the lower partition of which is constituted by a small portion 61 of this surface 13, this portion being in the form of a strip comprised between two generatrices of the drum.
  • this surface portion 61 extends between a retaining element 128 which is placed in contact with the surface 13 and a squeegee 57 of which an edge 58 is applied to this surface 13, this retaining element 128 and this squeegee 57 being disposed, respectively, upstream and downstream of the surface portion 61, with respect to the direction of movement F of the surface 13 of the drum.
  • the chamber 59 can be placed in communication with the interior of a cartridge 50, of cylindrical shape, which, housed in a shell 51 fixed above the chamber 59, can pivot around its axis 52, this cartridge 50 containing particles of lubricating substance.
  • the shell 51 is provided, at its lower part, with a recess 53 established so as to allow part of the cylindrical wall of the cartridge 50 to protrude out of this shell and thus to serve as an upper partition for the chamber 59
  • the cartridge 50 and the shell 51 are positioned relative to the drum, so that the axis 52 of the cartridge is parallel to the axis of rotation 11 of this drum and that the distance which separates this cartridge 50 from the surface portion 61 is very small, compared to the diameter of this cartridge.
  • FIG. 4 also shows that the shell 51 is provided with a clearance 54 for the passage of an actuating lever 55 integral with the cartridge 50, this lever 55 being able to be moved by the operator between two limit positions, the first of which is shown in dashed lines in FIG. 4 and the second of which is shown in solid lines in this same figure.
  • the cylindrical wall of the cartridge 50 is pierced with an opening 56 which extends in a direction parallel to the pivot axis 52 of the cartridge and which is produced so that, when the actuating lever 55 is placed in its first position, this opening 56 is closed by the wall of the housing of the shell in which is this cartridge, while when the lever 55 is placed in its second position, this opening 56 arrives opposite the recess 53 of the shell 51 and allows the particles of lubricating substance contained in the cartridge 50 to exit the latter and thus fall into the chamber 59. These particles then form, in this chamber, a small reserve of particles which is constantly in contact with the surface portion 61 which was mentioned above.
  • the chamber 59 which extends essentially in a direction parallel to the axis of rotation of the drum, is closed at its two ends, by two side plates which have not been shown in the drawings for reasons of simplification.
  • an elastic bead 60 fixed near the edge 58 of the squeegee 57 and interposed between this squeegee and the cartridge 50, guarantees practically complete sealing of the chamber 59. Under these conditions, the particles which are accumulated in the chamber 59 theoretically can't get out of this room.
  • the amount of lubricant which is deposited per unit area on the drum 10 depends on the force with which this squeegee is applied to this drum. More precisely, it has been found that, when the force P exerted, per unit of length, on the edge 58 of the squeegee in contact with the drum had a value of 12.5 N / dm, the quantity of lubricant deposited by unit area was approximately 0.06 mg / m2. Likewise, when this force P had a value of 7.5 N / dm, the quantity of lubricant which was deposited per unit of area was substantially equal to 0.07 mg / m2.
  • this flexible blade can be a polyethylene terephthalate blade, the latter material, usually referred to as "Mylar” (registered trademark), having a module of elasticity practically equal to 480 dN / mm2, the free part of this blade having a width a practically equal to 8 mm and a thickness e practically equal to 0.2 mm.
  • Mylar registered trademark
  • the force P which is exerted, per unit of length, on the edge 58 of this blade, when the latter is subjected to a bending f equal to half the width a of the blade, that is to say here at 4 mm then has the value:
  • the quantity of lubricating substance deposited, per unit of area, on the drum 10 is substantially equal to 0.07 mg / m2.
  • the flexible blade can also be a stainless steel blade, having a modulus of elasticity practically equal to 25,000 dN / mm2, the free part of this blade having a width a practically equal to 8 mm and a thickness e practically equal to 0, 05 mm.
  • the quantity of lubricating substance deposited, per unit of area, on the drum 10 is substantially equal to 0.073 mg / m2.
  • the retaining element 128 which equips the device for applying the lubricating substance that has just been described is in the form of a pad made of a very flexible material such as, for example, foam rubber or a textile material.
  • the cleaning device 22 is arranged in the immediate vicinity of the lubricant applicator device, upstream thereof, and the felt pad which equips this device cleaning device is positioned so that it then acts, for this applicator device, as a retaining element 128.
  • the lubricating substance which is produced according to the invention is deposited on the surface of the drum 10 so that the quantity of substance deposited per square meter of surface remains between 0.02 mg and 0.08 mg. It was found, under these conditions, that the surface of the drum was properly lubricated and that, even in the case where the speed of movement of this surface reached 1.5 m / s, the heating caused by the friction of the organ d The recording and erasing on this surface were negligible.
  • the magnetic drum is electrically connected to earth and each of the particles of lubricating substance is coated, over its entire external surface, with a layer of conductive carbon, the electric charges that these particles could acquire as a result of friction, during their passage under the erasing device or the recording member by example, are systematically eliminated. Therefore, these lubricating particles, which are uniformly distributed over the surface of the drum, do not risk electrostatically attracting the developer particles when they pass in front of the developer applicator device 16, thus avoiding the formation, on the sheet of paper 20, of a background detrimental to good print quality.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Photographic Developing Apparatuses (AREA)
  • Cleaning In Electrography (AREA)
  • Lubricants (AREA)

Claims (11)

  1. Pulverförmige Gleitsubstanz, die auf die Außenfläche (13) eines Aufzeichnungsträgers (10) eines magnetischen Druckers aufgebracht werden kann, wobei die Substanz aus Teilchen (30) aus einem pulverförmigen, isolierenden Stoff gebildet ist, der in der Lage ist, die Reibung zwischen der Fläche (13) und einer Aufzeichnungseinrichtung (12) zu vermindern, die gegen diese Fläche angedrückt wird, dadurch gekennzeichnet, daß die Substanz außerdem Teilchen (31) aus leitendem Kohlenstoff enthält, die um die isolierenden Teilchen (30) herum angeordnet sind, um Gruppen von Gleitteilchen (G) zu bilden, wobei das Verhältnis der Gesamtmasse des Kohlenstoffes zu der des isolierenden Stoffes zwischen 0,2 und 1 liegt.
  2. Pulverförmige Gleitsubstanz nach Anspruch 1, dadurch gekennzeichnet, daß die Teilchen (31) aus leitendem Kohlenstoff jedes der isolierenden Teilchen (30) vollständig umgeben.
  3. Pulverförmige Gleitsubstanz nach einem der Ansprüche 1 und 2, dadurch gekennzeichnet, daß die Größe jedes der Kohlenstoffteilchen (31) etwa hundertmal kleiner ist als die der Teilchen (30) aus isolierendem Stoff.
  4. Pulverförmige Gleitsubstanz nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß jedes Teilchen (30) aus isolierendem Stoff eine Größe in der Größenordnung von etwa 1µm hat.
  5. Vorrichtung zum Aufbringen einer pulverförmigen Gleitsubstanz auf die Außenfläche des Aufzeichnungsträgers eines magnetischen Druckers, die aufweist:
    - einen Behälter (35), der die pulverförmige Substanz enthält und an seinem Unterteil eine Öffnung (41) aufweist, die so geformt ist, daß bei der Mitnahme des Trägers alle Punkte dieser Fläche unter der Öffnung vorbeilaufen können,
    dadurch gekennzeichnet, daß sie außerdem aufweist:
    - eine Vielzahl von sehr geschmeidigen Fäden (42), die sich durch die Öffnung erstrecken, um mit der Außenfläche in Kontakt zu kommen, wobei die Anzahl dieser Fäden ausreichend ist, um eine Quasiversperrung der Öffnung hervorzurufen, so daß im Laufe der Verschiebung des Aufzeichnungsträgers diese Fäden relativ zueinander in Bewegung gebracht werden und es den Gleitmittelteilchen, die in den verwickelten Fäden gefangen sind, ermöglichen, entlang dieser Fäden zu gleiten, um auf die Fläche zu fallen.
  6. Vorrichtung nach Anspruch 5, dadurch gekennzeichnet, daß die Anzahl H der Fäden (42) zwischen zwei Grenzwerten Nm und NM liegt, die jeweils durch die folgenen Ausdrücke gegeben sind:
    Figure imgb0009
     wobei Σ für den Wert der Querschnittfläche der Öffnung (41) und d für den Wert des Durchmessers jedes Fadens stehen.
  7. Vorrichtung zum Aufbringen einer pulverförmigen Gleitsubstanz auf die Außenfläche eines Aufzeichnungsträgers eines magnetischen Druckers, mit einer Kammer (59), die die pulverförmige Substanz enthält, wobei diese Kammer über der Außenfläche liegt und an ihrem Unterteil durch einen Abschnitt (61) der Außenfläche begrenzt ist, und wobei sich der Abschnitt (61) zwischen einem Rückhalteelement (128), das mit der Fläche in Kontakt steht, und einer Rakel (57) erstreckt, deren eine Kante (58) gegen diese Fläche angedrückt wird, wobei das Rückhalteelement oberhalb und diese Rakel unterhalb des Flächenabschnitts (61) bezüglich der Verschiebungsrichtung (F) des Aufzeichnungsträgers angeordnet ist, dadurch gekennzeichnet, daß die Rakel (57) mit der Halbtangente (T) an der Außenfläche, die durch den Berührungspunkt dieser Rakel mit dieser Fläche verläuft und in der Verschiebungsrichtung (F) ausgerichtet ist, einen Winkel (t) bildet, dessen Größe zwischen zehn und dreißig Grad liegt.
  8. Vorrichtung nach Anspruch 7, dadurch gekennzeichnet, daß die Kraft (P), die pro Längeneinheit auf die Kante (58) der Rakel ausgeübt wird, die mit der Fläche des Aufzeichnungsträgers in Kontakt steht, so eingestellt ist, daß die Menge der Gleitsubstanz, die unter der Rakel vorbeiläuft und so auf dieser Fläche abgelagert wird, zwischen 0,04 und 0,08 mg/m² bleibt.
  9. Vorrichtung nach einem der Ansprüche 7 und 8, dadurch gekennzeichnet, daß die Rakel (57) durch eine flexible Klinge gebildet ist, die aus einem Material hergestellt ist, das einen Elastizitätsmodul von wenigstens gleich 300 dH/mm² und eine Vickers-Härte von höchstens gleich 600 aufweist.
  10. Magnetographische Druckmaschine, dadurch gekennzeichnet, daß sie eine Vorrichtung zum Aufbringen einer pulverförmigen Gleitsubstanz nach einem der Ansprüche 5 bis 9 aufweist.
  11. Magnetographische Druckmaschine, dadurch gekennzeichnet, daß ihr Aufzeichnungsträger mittels der pulverförmigen Gleitsubstanz nach einem der Ansprüche 1 bis 4 geschmiert ist.
EP19880401089 1987-05-07 1988-05-04 Pulverförmige Substanz zur Reibungsverminderung des Aufnahmeträgers eines magnetischen Druckers Expired - Lifetime EP0291392B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8706510 1987-05-07
FR8706510A FR2615011B1 (fr) 1987-05-07 1987-05-07 Substance pulverulente pour la lubrification du support d'enregistrement d'une imprimante magnetique

Publications (2)

Publication Number Publication Date
EP0291392A1 EP0291392A1 (de) 1988-11-17
EP0291392B1 true EP0291392B1 (de) 1992-10-14

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EP19880401089 Expired - Lifetime EP0291392B1 (de) 1987-05-07 1988-05-04 Pulverförmige Substanz zur Reibungsverminderung des Aufnahmeträgers eines magnetischen Druckers

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US (1) US4831386A (de)
EP (1) EP0291392B1 (de)
DE (1) DE3875274T2 (de)
FR (1) FR2615011B1 (de)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5510886A (en) * 1993-04-03 1996-04-23 Ricoh Company, Ltd. Image forming apparatus having an intermediate image carrier

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5866952A (ja) * 1981-10-16 1983-04-21 Ricoh Co Ltd 静電記録方法
US4477198A (en) * 1982-06-15 1984-10-16 International Business Machines Corporation Modified resistive layer in thermal transfer medium having lubricating contact graphite coating
JPS59202480A (ja) * 1983-05-04 1984-11-16 Fuji Xerox Co Ltd 磁気記録媒体用潤滑剤
JPS59226371A (ja) * 1983-06-06 1984-12-19 Canon Inc クリ−ニング装置
JPS6012571A (ja) * 1983-07-04 1985-01-22 Canon Inc クリ−ニング装置

Also Published As

Publication number Publication date
DE3875274T2 (de) 1993-02-25
EP0291392A1 (de) 1988-11-17
US4831386A (en) 1989-05-16
DE3875274D1 (de) 1992-11-19
FR2615011A1 (fr) 1988-11-10
FR2615011B1 (fr) 1989-06-23

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