Abstract: A direct electrostatic printing method performed in consecutive print cycles in which control signal pulses are applied on the one hand between a toner particle source and a back electrode and, on the other hand, between the toner particle source and electrodes on a printhead structure interposed between the toner particle source and the back electrode. The pulses are so controlled as to be in accordance with an image configuration to generate a pattern of electrostatic fields which selectively permit or restrict the transport of charged toner particles from the particle source toward the back electrode via the printhead structure.

Abstract: An image recording device and method for recording an image onto an information carrier. The intermediate image receiving member is flexible under a tension and has a first face and a second face. A pigment image is formed on the first face of the intermediate image receiving member, which pigment image is subsequently transferred to an information carrier.

Abstract: An image recording device and method for recording an image to an information carrier. An intermediate image receiving member and a printhead structure move relative to each other during recording. The image recording device comprises an intermediate image receiving member position measuring means for measuring the position of the intermediate image receiving member in relation to the apertures to thereby via the control unit be able to synchronize the selective opening and closing of apertures through a printhead structure according to the relative movement of the printhead structure and the intermediate image receiving member to thereby enable the formation of a pigment image at a predetermined position on the intermediate image receiving member in view of the image which is to be recorded. The pigment image is subsequently transferred to an information carrier.

Abstract: An image recording device and method for recording an image to an information carrier. An intermediate image receiving member has a first face and a second face. The printhead structure is placed inbetween a pigment particle source and the first face of the intermediate image receiving member. The image recording device comprises a pressure changing means which can create a pressure difference on the side of a second face of the intermediate image receiving member in the vicinity of apertures used for pigment particle control. The intermediate image receiving member comprises a cleaning area for cleaning purposes and a separate image area intended for reception of pigment particles for formation of a pigment image thereon.

Abstract: A direct electrostatic printing method and apparatus decrease the adhesion force of toner particles on a toner particle source. The method includes the steps of coating the toner particle source with a plurality of layers of toner particles and vibrating the toner particle source so that the toner particles break up to form one fluidised layer of toner. The toner particle supply apparatus includes a toner feed source supplying toner particles to a rotating developer sleeve to form a multilayer coating of toner particles on the developer sleeve. A vibration generating device is arranged adjacent to, or on a surface of the developer sleeve to break up the toner particles to form one fluidised layer of toner.

Abstract: A printhead structure and a method are used in direct electrostatic printing wherein streams of charged toner particles from a source of toner particles are directed onto an image carrier, such as a sheet of paper. A first set of print electrodes surround apertures through which the streams of toner particles flow. Voltages are selectively applied to the print electrodes to control the flow of toner particles through the respective apertures. A set of deflection electrodes are also associated with the apertures. Deflection voltages from at least one deflection voltage source are applied to the deflection electrodes to increase the convergence of the toner particles onto the information carrier and also to control the trajectories of the toner particles onto predetermined dot locations on the information carrier so that each aperture may provide toner particles to multiple lateral locations on the information carrier.

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: 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 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.