Abstract: An information display device including, as main components, a thermosensitive material layer which can be gradually converted between a completely opaque state and a completely transparent state under the influence of temperature, an electrode matrix, a control device for multiplexing, scanning or pulsating control signals to the individually addressable electrodes, possibly together with a colored backing layer. The electrodes in the matrix are connected via heating means at the electrode crossing points. At each crossing point there is further positioned a current valve means (diode) or a separate driver circuit for each heating means.

Abstract: A method for improving the print quality of an image recording apparatus in which charged particles are deposited in an image configuration on an information carrier is described.

Abstract: The present invention relates to a method and means to control one or several electrodes in a print unit, comprising: at least one toner carrier, electrode means, having apertures at least partly surrounded by said electrodes, at least one back electrode. The electrodes are connected to driving means to apply different levels of energy, an on-potential, to at least partly open passages through the apertures to allow passage of toner particles or, an off-potential to prevent the passage of toner particles provided on the toner carrier through the apertures towards the back electrode. The driving means of each electrode intended to permit passage of said toner particles is brought in a high resistive state, and the electrode means of the electrodes intended to block the passage of said toner particles are brought in a low resistive state. Then all electrodes are applied a dynamic potential.

Abstract: The present invention relates to a method for improving the print quality of an image recording apparatus in which charged particles are transported from a particle source and deposited in an image configuration on an information carrier. Variable control voltages are supplied to control electrodes to permit or restrict the transport of charged particles from the particle source during a predetermined print time. The control voltage levels, the print time length or the voltage levels and the print time length are dimensioned in relation to the specific distance between each control electrode and the particle source. The present invention relates also to a device for accomplishing the method.

Abstract: An apparatus for printing directly on plain paper, utilizing an arrayed control grid having a plurality of toner slots disposed in a space between a toner carrier and a backing electrode on which a paper travels. The backing electrode formed in a flat plate facing paralleledly to the control grid assures a uniform electrostatic field in an interspace therebetween. A unit body associated with the toner carrier and the control grid makes the interspace open when the unit body is removed from the apparatus body which offers an easy access to the interspace and the members as well. A resiliently suspended backing electrode with a spacer, a restriction member etc., assures the interspace constant. Other unit bodies including the control grid associated with the backing electrode and others are also disclosed.

Abstract: Method to improve the printing quality at reproduction of half-tone originals by means of printers of the type, in which a number of dots are brought together in a cell (pixel). A minimum of two dots form a cell where each dot in the cell is controlled individually with respect to the size and/or the color value. The dots form a pattern in each cell, which is variable with respect to the number of dots, the dot size and/or the dot color value.

Abstract: An apparatus and method provide direct electrostatic printing onto an information carrier. Computer-generated electronic signals define an image and are converted to a pattern of electrostatic fields to selectively control the deposition of charged toner particles in an image configuration directly onto the information carrier. The electrostatic fields are applied via a set of print electrodes which selectively permit or restrict the transport of the charged toner particles from a particle source toward the information carrier. Periodically variable deflection potentials are applied to a set of deflection electrodes to modify the trajectories of the toner particles as they are transported toward the information carrier to direct the toner particles in a direction transverse to the direction of the movement of the information carrier.

Abstract: A method and device to enhance the printing quality of direct electrostatic printers which utilize an electrode array and electrical signals to generate an electrical field to cause toner particles to be deposited directly onto plain paper to form visible images. The invention relates to an improvement to dynamically position and maintain a desired distance between the electrode array and the surface of the charged particles on the particle carrier.

Abstract: A method and apparatus for improving printing quality in electrographic printers includes an electrode device for generating a latent electrostatic charge pattern from electric signals. The electrode device is arranged within a gap area between a particle carrier and a back electrode. During a portion of the operating cycle, preferably when no development is performed, a duel airflow that is charged with positive and/or negative ions is directed into the gap area to neutralize the electrostatic attraction forces between the toner particles, and the electrode device and for achieving a homogeneous charge level on the surface layer of the electrode device. A magnet can be positioned opposite the electrode device so as to attract toner particles.

Abstract: Method and device for high quality printing with substantially reduced cross-coupling while reducing the manufacturing cost of printers that use a matrix of individual control electrode units by connecting individual control electrode segments in series to reduce the number of electronic drive circuits. An information carrier such as paper is placed between a back electrode and an electrode matrix both of which are connected to voltage sources. Voltage sources connected to the control electrode unit matrix at least partially open and close passages through the electrode matrix; charged pigment particles attracted from a particle carrier through the open passages are deposited on the information carrier to form visible images.

Abstract: Device for generating multicolor images which employs a latent electric charge pattern and development of this on an information carrier (21) using toner particles (16) of different colors. Separate developers (10-13) are used for each color. Each developer (10-13) is individually provided with a toner carrier, preferably a conductive developer roll (14) and a back electrode (23) which cooperates with the developer roll by attraction forces. An electrode unit (29) is arranged between the conductive developer roll and the back electrode 23. The electrode unit (29) includes at least one electrode layer/direction (22), essentially including relative parallel electrodes, which are common for all developers (10-13), and a plurality of apertures (27). The apertures (27) are opened and closed respectively by signals from at least one driving device (25).

Abstract: A method and device for improving the printing performance of electrographic printers, in which a latent electrical charge pattern of electric signals is produced by an electrode matrix or the like, which temporarily produces electrical fields for attraction of pigment particles toward an information carrier. The electrodes of the electrode matrix are exposed, during at least a portion of the time between the printing of subsequent paper sheets, to a cleaning force which removes the pigment particles from the electrode matrix.

Abstract: A latent electrical charge pattern of electrical signals is produced by an electrode matrix. Apertures between the electrodes are opened and closed, respectively, to expose electric fields for the attraction of pigment particles of toner against an information carrier. The electrical charge pattern electrostatically controls the transmission of electrical fields through the apertures of the matrix to attract particles of toner against the information carrier. The apertures are opened and closed by generating electrostatic fields between the electrode layer, particle supply and backing electrode. Each electrode is arranged on a carrier to completely surround one aperture and is individually connected to a voltage source to supply the electrical signals.

Abstract: An apparatus and method for printing directly on plain paper, utilizing an arrayed control grid having a plurality of toner slots. An alternating electrostatic field in a space between a toner carrier and a backing electrode gives toner a vibrational motion to prevent a toner clog at the slot. The field is also formed to repel the clogged toner back to the toner carrier, or to fall it down on a paper on the backing electrode during no print is performed to clean the control grid. A constitution of conductive and dielectric materials for the members assures to form the field.

Abstract: An image-forming device for an electrographic printer, in which a latent electrical charge pattern of electrical signals is produced in an electrode unit having an electrode matrix situated between a particle carrier and a backing electrode. The matrix comprises a screen or grid of electrodes and a plurality of apertures. The apertures are partly opened and closed electrostatically for the controlled transmission of pigment particles of toner to an information carrier (e.g., paper). The electrodes and other surfaces of the device which are contacted by the pigment particles are provided with a layer of antistatic coating of an electrically conductive or semiconductive material. Tribo friction charges which are produced between the pigment particles and the electrodes and other surfaces are transported by the antistatic coating to a control unit which is connected to ground and which conducts the tribo charges from the device.

Abstract: Method and device to improve printing quality and the repetition accuracy of electrographical printers, in which are produced a latent electric charge pattern of electrical signals by means of an electrode matrix or the like, which respectively opens and closes passages between electrodes for exposing electric fields for attraction of pigment particles (11) against an information carrier (7). The electrodes (1,2) of the electrode matrix in the area about one or several open passages (3) are screened electrostatically against closed passages, by means of at least two electrically isolated electrodes (1,2).

Abstract: Method and device to improve the printing quality and thereby the readability of the print of electrographic printers. An information carrier is brought into electric cooperation with at least one screen grid shaped electrode matrix, which by control in accordnace to the configuration desired pattern at least partly opens and closes passages through the matrix by galvanic connection to this to at at least one voltage source. Through thus opened passages electrical fields are exposed for attraction of pigment particles against the information carrier. This is locateable between said electrode matrix and a background electrode. This contains counter electrodes (8,8') in the form of galvanically separated sections, which are suibstantially symmetrically located above respective line of passages in the electrode matrix.