A magnetic recording medium (13) having a triple layered structure including a substrate (8), a first layer or a soft magnetic thin film (9) of high permeability piled on the substrate (8), a second layer or a vertical magnetization film (10) piled on the first layer (9), a third layer or a soft magnetic film (11) of high permeability piled on the second layer (10). A magnetic recording apparatus (FIG.1) alternately switches the magnetization orientations of the second layer or the vertical magnetization film (10) at a recording location where a latent image is to be formed. The first and third layer or the soft magnetic thin films (9 and 11) can improve recording efficiency. The field produced by the second layer or the vertical magnetization film (10) causes the third layer or the soft magnetic thin film (11) to be magnetized along the surface (20) of the magnetic recording medium (13), and this results in the concentration of the flux owing to switching of the magnetization directions. This enables high density recording and improves recording sensitivity and reproducing sensitivity.

L'invention concerne un dispositif pour appliquer, de façon intermittente, des particules d'un révélateur pulvérulent sur la surface d'enregistrement d'une imprimante magnétographique.

Ce dispositif comprend un réservoir (17) contenant des particules de révélateur, un élément de transport (23) pour amener ces particules au voisinage de la surface d'un tambour magnétique (11), un déflecteur (24) interposé entre cet élément de transport et ce tambour pour appliquer des particules sur la surface de celui-ci, et une raclette (45) disposée entre ce déflecteur et le poste de transfert (H) et actionnée par un électro-­aimant (EA) pour retirer sélectivement les particules qui ont été déposées sur la surface de ce tambour.

Application aux imprimantes magnétographiques.

A magnetic head array for use in a magnetographic printer, in which local magnetic fields are generated by U-shaped wires each having a complete magnetic yoke, can be made easily by bending a foil (12), formed by parallel wires consisting alternately of conductive (2A - 2D) and soft-magnetic (3A - 3E) material, about a thin sheet (1) of soft-magnetic material.

In a magnetographic printer the array is brought into contact by the bend with a magnetizable medium (11). The areas magnetized by the individual wires (2A - 2D) are sharply defined.

An apparatus is provided for reproducing a final image in a magnetic image-storing medium which is transported through an imaging-producing zone, the reproduced final image being made up of a plurality of individual magnetic image units. The apparatus includes an array of co-planarly disposed, adjacent magnetic writing heads, each head being connectable to the controller to produce an image unit of the final image, the heads being arranged in generally aligned sets. Division guide means are interposed between adjacent sets of heads for facilitating subsequent replacement of one or more sets of the array.

A cleaning apparatus for a recording head in a magnetographic printing device of the type having a movable magnetic imaging tape (16) in endless belt form. The apparatus is especially effective for cleaning thermal printheads for thermoremanent magnetic imaging systems, and comprises a cleaning member (14) adapted for reciprocal movement into and out of a nip formed by the magnetic tape (16) and the printhead (52). In one embodiment, the cleaning member is a flexible substrate attached at one end to a rotatably mounted spool (58). The substrate is wound on the spool with the loose end resting on a guide plate (60) and confronting the nip. The spool is periodically rotated to drive the substrate through the nip while the tape is moving and then is rotated in the opposite direction to rewind the substrate and withdraw it from the nip. Alternatively (see Figure 8), the cleaning member is a flexible substrate (56A) which is maintained in a planar configuration by parallel guide plates (74). A tractor wheel drive (76) reciprocally moves the cleaning member into and out of the nip. The cleaning member may be a non-conductive, woven material having open spaces therein or a two layered composite having a non-conductive screen on one side to contact the tape and a carpet of short bristles on the other side (see Figure 5) to clean the printhead. Optionally, lateral movement of the cleaning member is provided after it enters the nip and the heating elements of the printhead may be momentarily energized to heat and soften the toner accumulated on the printhead to enhance the cleaning efficiency of the apparatus.

Apparatus for producing a magnetic image in a magnetic image storage medium. The apparatus includes a thin-film magnetic web (12) with a pole-defining face and a second thin-film blanket (24) magnetically spaced from the first magnetic web and having a second surface defining a second pole face. Spaced from the pole faces is a diamagnetic spacer (16) which forms a special back gap in the magnetic circuit. An electrical coil (20b) sandwiched between the two magnetic materials induces flux in them. The spacer (16) may extend normal to the flux path beyond the effective flux paths otherwise existing in the web and blanket.

L'invention concerne un dispositif pour appliquer, sur le support d'enregistrement d'une imprimante non-impact, des particules solides de révélateur contenues dans un réservoir.

Ce dispositif comprend, d'une part un rouleau de transport (22) qui amène les particules de révélateur depuis le réservoir (15) jusqu'à proximité du tambour d'enregistrement (10), d'autre part, un déflecteur (23) interposé entre ce rouleau (22) et ce tambour (10), ce rouleau (22) étant revêtu de bandes magnétisées présentant sur leur surface externe des lignes magnétiques hélicoïdales telles que, sur deux bandes contigûes, le pas des lignes magnétiques d'une bande est opposé à celui de l'autre bande.

Application aux imprimantes magnétiques.

Improved resolution of magnetic toner image on a substrate is obtained by removing excess toner from a recording member containing parallel lines of flux by passing an air flow substantially parallel to the premagnetization line pattern to remove excess toner prior to toner transfer to the substrate.

An electrostatic printing process is disclosed wherein a printing roll (18, 18', 18") is formed by forming a latent magnetic image in a magnetic imaging member (13), decorating (14, 15) the latent magnetic image with a non-conductive magnetic toner to form a toner image, transferring the toner image to a conductive member (18, 18', 18") and temporarily fixing (19) the toner image to the conductive member. The toner image on the conductive member (18,18', 18") is electrostatically charged (21, 22, 23), while the charge is dissipated from the remaining area of the conductive member. The charged image of magnetic toner is decorated (24, 25, 26) with an electrostatic toner comprising a colorant and a binder resin to form an electrostatic image which is transferred to a substrate (27). Pattern change is accomplished by washing off the fused toner from the conductive print roll (18, 18', 18") and forming a new fused toner image on it.