Abstract: An apparatus for electrophotographic production of images on a printing medium, such as a printer or copier, has a printing unit fed with toner from a toner storage tank. Toner can be refilled into the tank through a closable opening without interrupting the printing operation.

Abstract: A printing device, in particular a printer or a copier, which includes a first electrographic printing unit for printing an image pattern on a sheet-type material in a first transfer printing transport path as well as a second electrographic printing unit for printing an image pattern on a sheet-type material in a second transfer printing transport path, and further including an input section via which the sheet-type material can be supplied individually one after the other to both the first and second electrographic printing units, and further having an output section via which the printed sheet-type material from either the first or second electrographic printing units is ejected individually one after the other.

Abstract: A printer or copier has a developer station with a toner dispenser in which the toner is fed from a toner box to a transverse transport above a dosing apparatus. The transverse transport includes a helix driven by a drive mechanism. The helix has a pitch H that varies along its length or a thickness D that varies along its length so that the speed of conveyance in the transverse direction decreases over the conveyance path. The rotational speed of the helix is variable by adjustment of the effective length of a drive arm or an extent of an eccentric.

Abstract: A method for multicolor electrophotographic printing includes a photoconductive layer system having surface elements or surface regions that are provided with an initial negative potential, then are exposed to varying degrees and developed with negatively charged toner particles of a color. A uniform light source is arranged closed to the photoconductive layer system and then the surface elements are developed with a second color toner. In particular, the image being printed has image elements of different colors which correspond to different surface elements of the photoconductor. These surface elements are differently illuminated to achieve different potentials and are developed by color particles by depositing the color particles on the respective surface elements. The charge potential of ones of the surface elements is increased and then surface elements not covered by color particles are illuminated to reduce the charge potential there prior to subsequent development of further surface elements.

Abstract: An electrophotographic color printer includes a photoconductor and a printing unit for producing a toner image on the photoconductor. The printing unit is removably provided in a receptacle in the printer.

Abstract: A paper decurling unit in a printer or copier provides a convex or concave path in the paper transport direction. The decurling device is adjustable.

Abstract: A printer or copier device has a developer station with fixing drums for fixing the toner image on the recording medium. A guide yoke guides the recording medium to the fixing drums. The guide yoke includes a deflector edge over which the recording medium is fed. The deflector is replaceable and is formed of wear-resistant material in the region that contacts the recording medium. The deflector edge may include a deflector element with a plurality of deflection edges and which can be rotated to expose different edges.

Abstract: A printer or copier has a developer station which uses a developer mix such as tone and developer. A temperature sensor is provided in the developer station to sense the temperature of the developer mix. The signal of the temperature sensor is fed to a control unit which effects a control of the copier or printer operation, such as by halting operation, effecting cooling, or triggering a warning signal when the temperature reaches an upper boundary.

Abstract: In a printer or copier, error conditions are sensed. A determination is made as to whether the error condition is readily repairable by the user and if so, the display unit displays information on the error condition, including instructions for repairing the error condition. If, on the other hand, the error condition is determined to be repairable only by a skilled technician, the display unit displays only the instructions to contact the skilled technician.

Abstract: A method for operating electrographic printers or copiers uses toner particles of two different colors applied to a toner image carrier by at least two developing units. A force field is applied to at least one section of the travel path of the toner particles from a toner container to the toner image carrier to cause the toner particles to be carried in the direction of the toner image carrier. Changing the force field causes an interruption of the transfer of the toner particles with the developer stations are in a rest position.

Abstract: A printer or copier has a developer station for a toner image wherein a photoconductive drum is provided with a latent charge image that is developed by applying a toner/air mixture to a developer drum that in turn applies the toner to the photoconductive drum. The toner is charged by a charging device as it is applied to the developer drum. A sensor senses the toner on the developer drum and a control varies the quantity of toner applied. The sensor is an optical sensor or a capacitive sensor, and the charge applied to the toner by the charging device is varied depending on the sensor output. A voltage applied to the developer drum may also be varied.

Abstract: A transfer printing station is provided which has two pairs of tractor drives movably arranged side-by-side on two drive shafts. During operation with only a single paper web, the unused tractor drives can be moved to a lateral parking position. The two pairs of tractor drives can be easily moved to match two different webs of paper of different widths. The structure enables a user to adapt the paper conveyor of a transfer printing station to operate with only a single paper web or two parallel webs.

Abstract: A process is described for printing a print image on a continuous support material relative to a pre-set position in an electrophotographic printer in which a stepper motor controlled by an electric impulse sequence drives a transport device.

Abstract: A printer or copier has a photoconductor on which charge patterns are formed that are in turn inked and printed onto a recording medium. An optimized exposure energy is determined for a given potential of the photoconductor by calculating a sensitivity factor. The optimized charge potential may also be calculated on the basis of the sensitivity factor for a given exposure energy.

Abstract: In an electrophotographic printing process as well as an electrophotographic printer for printing a substrate, a photo-sensitive layered system is brought to a homogeneous initial state by impressing an electrical field having a first direction. The photoconductive layer is exposed with predetermined image structures according to the image. The entire photoconductive layer is exposed uniformly through the cover layer and/or the electrode layer. Charged toner particles are applied to the cover layer in a development step. The toner image is then transferred to the substrate. If more than one copy is required, the development step and the transfer step are carried out a number of times, the electrical charge image present inside the layered system being retained. The substrate is conveyed at a very high speed by a conveyor device in this operational state.

Abstract: A developer unit for an electrographic printer or copier has a toner receiving surface designed to receive a coating of toner particles. A toner mass sensor and a toner charge sensor measure a coting of toner particles on the toner receiving surface and send signals to an evaluation unit which calculates a mass-referred toner charge.

Abstract: For regulating the pressure in a pressure chamber, in particular in a pneumatic brake apparatus for a web-type recording medium, an actual pressure is set in the pressure chamber dependent on an actual angle of rotation of a rotary valve. The actual angle of rotation of the rotary valve and the actual pressure in the pressure chamber are acquired. A target pressure and a target angle of rotation allocated to this target pressure are predetermined, and a pressure deviation between the actual pressure and the target pressure are determined, as is a deviation of the angle of rotation between the actual angle of rotation and the target angle of rotation. An adjusting unit sets the angle of rotation at the rotary valve, first dependent on the deviation of the angle of rotation and then dependent on the pressure deviation. Furthermore, a sensor for acquiring the angle of rotation is specified.

Abstract: An electrographic printing unit containing at least two printing units whose transfer printing points lie opposite one another is shown and described. This configuration enables high-speed duplex printing. Also disclosed is a printing unit with a photoconducting band and two exposure units located along the perimeter thereof. The exposure units superimpose two latent images each time the photoconducting band rotates.

Abstract: In a multifunctional printing method and printing system, printed material is checked, verified and tracked. For that purpose different test equipments are located in-line with a printing line. Magnetic information being printed by a printing station onto the recording carrier using magnetic ink character readable toner may be in-line tested by a magnetic test equipment, which reads information from the magnetic recording zone on the carrier. Optical information may be tested by an in-line mounted optical test equipment, respectively. Further in-line test equipment is proposed such as a laser bar code scanner and an address reader. The printing line may comprise additional devices such as print preprocessing unwinders or print postprocessing stackers, folders or cutters.

Abstract: The invention relates to an aligning device (10) for individual sheet (12) alignment. The alignment device (10) comprises a sensor device (22, 24, 26, 28), a delivery device (18), and a transport device (14) located downstream from the delivery device in the direction of conveyance of the sheet (12). In order to align the sheet (12) the sensor device (22, 24, 26, 28) detects the side end of the sheet so that its position can be determined in relation to a desired printing position. The transport device (14) holding the sheet (12) is shifted in relation to the direction (16) in which the sheet (12) is conveyed so that the sheet (12) can be moved into the desired printing position. Before the sheet (12) is aligned the delivery device (18), which feeds the sheet (12) to the transport device (14), is opened.