Abstract: A method of forming visible images in which magnetically attractable toner powder comprising resin particles containing magnetically attractable material is introduced to an image forming zone between an image registration medium and a moving conveying medium which has, within said image forming zone, a magnetic induction of at least 0.2T at its surface, thus imparting a force of attraction on the toner powder in which image forming zone the toner powder is selectively deposited on the image registration medium by electrostatic attraction in accordance with an image pattern, the toner powder used containing no more than 3% by volume of the magnetically attractable material.

Abstract: An exposure device in which a row of LED's is provided in the form of parallelograms having unequal sides, in which each of the corner points of one short side of a light-emitting surface is always in line, as considered in a direction perpendicular to the row, with one of the corner points of the other short side of an adjacent light-emitting element, and a printing device in which said exposure device is used.

Abstract: An apparatus for detecting a sheet in a conveying path, comprising a light source and a light receiver on one side of the conveying path and a light-reflecting element in the form of a prism on the other side of the conveying path for reflecting for the light receiver a beam of light emitted by the light source, wherein the prism has a first reflecting surface opposite the light source, a second reflecting surface opposite the light receiver and a third reflecting surface which deflects, in the direction of the second reflecting surface, the beam of light reflected by the first reflecting surface, so that the apparatus is less sensitive to deviations of the position of the prism with respect to the light source and the light receiver.

Abstract: A printing device for reproducing information, comprising a movable image-forming element having a dielectric surface, an image-forming station including a magnetic roller provided with a rotatable electrically conductive sleeve and a magnetic system within the electrically conductive sleeve, electrodes to generate an electric field between the image-forming element and the magnetic roller in accordance with an information pattern, while an electrically conductive magnetically attractable toner powder is present in an image-development zone formed between the image-forming element and magnetic roller, the magnetic system generating a magnetic field in the image-forming zone and forming the toner powder into a magnetic toner brush and system for providing a well-defined space in the image-development zone between the electrically conductive sleeve and the image-forming element so that no distortion of the magnetic toner brush occurs during image development in the image-development zone.

Abstract: A method of distributing status information is described, regarding a digraph in a logically organized system of groups of entities related to each other and to be represented by digraphs, and a device for using such a method. In a system which comprises a number of groups which may be represented by digraphs, the lacking of a node having a particular status in a group is detected by the method. When applying the method to a distributed object-oriented system, in which a root is such a node having a particular status, incremental distributed garbage collection is realized. The invention is also effective in the case in which cycles or subcycles occur in graph of objects referring to each other. Upon realizing garbage collection, inaccessible data information occupying memory space is removed from memory to thereby free previously occupied memory space.

Abstract: A fluorine-doped tin oxide powder is prepared by combining a solution of a stannic salt with a solution of a fluoride, separating the tin hydroxide from the liquid and drying it at a temperature not exceeding about room temperature and heating the dried product to at least 500.degree. C., until the fluorine content is less than 10% and preferably is between 1 and 5% by weight. The fluorine-doped tin oxide powder of the invention can be used for the manufacture of electrically conductive toner powder.

Abstract: A device for guiding a sheet at the exit side of a transport nip formed by a pair of rollers is provided with a movable guide member having a thin end. When the device is in a position of rest, the guide member occupies a position such that the thin end is situated close to but not touching the transport nip. The leading edge of a sheet fed through the transport nip is intercepted by the thin end of the guide member, by means of an operative electrostatic force, whereafter the sheet pushes the guide member ahead of itself and is thereby separated from the nip-forming surfaces of the pair of rollers.

Abstract: A folding and depositing device for drawings provided with legends, comprising two folding stations for folding drawings in two directions at right angles to one another and a collecting station for depositing the folded drawings with their legends on the same side such that the folding stations fold drawings of a first group of formats (A1 and A2), first in the longitudinal direction and then in the transverse direction, and fold drawings of a second group of formats (A0 and A3), first in the transverse direction and then in the longitudinal direction and, depending on the group to which they belong, the folded drawings are directed via different discharge paths from the second folding station to the collecting station, and wherein an intermediate transport path between the folding stations is accessible via a routing switch to enable a subsequent drawing to be folded in the first folding station while a previous drawing is being transversely transported to the second folding station.

Abstract: A method and apparatus for forming a multi-color image in which colored toner powder is used to form color separation images in the secondary colors magenta, cyan and yellow and also in one of the primary colors red, green or blue, such that of the color separation images formed in the secondary colors, there is formed, with transparent toner powder, at least as many color separation images so that the two primary colors not formed as separate separation images, are represented therein, affording the possibility of forming multi-color images by means of combinations of transparent and non-transparent toner powders, the method being performed by combining on an intermediate support those separation images formed with toner powder not required to be transparent and then transferring them to an image receiving material and subsequently transferring in registration to the image receiving material those separation images which are required to be formed with transparent toner powder.

Abstract: A toner powder comprising toner particles which carry on their surface and/or in an edge zone close to the surface fine particles of electrically conductive material consisting of fluorine-doped tin oxide. The fluorine-doped tin oxide particles have a primary particle size of less than 0.2 micrometer and a specific electrical resistance of at most 50 ohms.meter. The fluorine content of the tin oxide is less than 10% by weight, and preferably is from 1 to 5% by weight.

Abstract: A holder for receiving sheets and discharging sheets therefrom one-by-one from the bottom of a stack of sheets is provided including a carrier having a rear portion, an intermediate portion and a front portion, providing a carrying surface for the sheets, the carrier being bent at the intermediate portion thereof, transverse to the direction of conveyance of the sheets, so as to create a deepened section between the rear portion and the front portion. Lateral supports extend from lateral edges of the carrier, with at least one elevated part provided in the deepened section at the intermediate portion extending transverse to the direction of conveyance on the carrying surface of the carrier.

Abstract: A device for selectively recording charges for copies made on a copying machine by way of two or more accounting means connected at the same time via the device to the copying machine, comprising means for coupling the device to the copying machine, a plurality of connection points each one of which is connectable separately to a different accounting means and control means which selectively activates one of the accounting means for recording of the charges and the method of accomplishing the recording of such charges.

Abstract: A stackable drop generator for an ink-jet printer made up of a number of stackable elements in the form of flat plates, each plate comprising a pressure chamber, a supply chamber and a piezo-element for forming a pressure wave in the ink in the pressure chamber, and in which elements are so disposed on either side of a first or intermediate element such that the pressure chambers of the elements are not in line with the pressure chamber of the intermediate element.

Abstract: A method for checking in a text processing system the correct and consistent use of units, comprising the steps of: storing a list of symbols or production rules that represent units; storing criteria, that state whether or not a symbol or a combination of symbols is interpreted as a unit; specifying allowable units and allowable notations thereof; searching the text for references to units, i.e., for strings that can be interpreted as a unit or part of a unit; checking whether the strings represent an allowable notation of an allowable unit; and generating an error signal, if not. If an unallowable unit is found, this unit and the associated number(s) may be transformed into an allowable unit.

Abstract: Image information relating to an image is printed in a laser printer by forming image elements according to a raster pattern of image points and printing dots in a fixed number N of the image points within each image element, N being smaller than the number of image points in an image element. The image points wherein a dot is to be printed are arranged into a cluster with a minimal perimeter. The dots printed within an image element are all printed with the same intensity and thus have the same diameter, and may overlap contiguous image points in order to fill up the total area of the image element. In an embodiment the position of the cluster within each image element is selected according to the image information.

Abstract: A method and apparatus for developing a latent magnetic image in which a layer of magnetically attractable toner powder having a specific resistance less than 10.sup.9 ohms.meter is conveyed by a toner conveyor to a developing zone past a medium carrying the latent image and an AC voltage is applied between the toner conveyor and the medium carrying the latent image.

Abstract: A desktop publishing system is adapted to the interactive makeup and management of documents according to a model, in which model a document is made up of one or more kinds of components characterized by contents, name and properties, and which model represents a number of text columns. For each text column a corresponding component column is at least partially reproduced on the screen. For each component an indication is displayed in the respective component column, the indication being in the form of an identification symbol of this component to identify the start of the contents of the component at the level of said component in the text column.

Abstract: A distributed office automation system includes workstations and support stations which are interconnected via a network and which make use of the functionality of one another by subcontracting tasks. Various function modules are available in the system for numerous tasks and the system provides a distributed organization structure in which it is always clear what function module is required to perform a specifc task. Each of the stations is provided with a coordination unit which is continually aware of the state of the total system and which designates the required function module.

Abstract: The present invention is a front-end system for the conversion of graphical data and coded font data into a serial pixel-bit stream for a raster output scanner, such as a laser printer. The front-end system includes a front-end controller, input/output means, which can be connected to a computer or a data network, and a memory for storing graphical data and coded font datat. Final printing format is determined by a fine formatter. The present front-end system also includes a bitmap memory for storing a bitmap representation of the page to be printed, a bitmap filler for expanding the data and placing them into the bitmap memory, and a bitmap reader. The functions of the front-end controller and of the input/output means are implemented in a first processor and the functions of the fine formatter and the bitmap filler are implemented in a second processor. The bitmap reader is formed by dedicated hardware logic.

Abstract: Boundaries between colored and uncolored image parts are reproduced on a pixel raster by determining a binary value ("colored" or "uncolored"), proceeding along a boundary, for adjoining pixels intersected by said boundary, said value being determined on the basis of the situation of said pixel with respect to the boundary and a carried-forward correction value. On the basis of the situation of said pixel with respect to the boundary a fractional value is calculated which is then rounded off to a binary pixel value. The rounding-off error made in such cases is processed using a prevention function for preventing allocating such binary values to the boundary pixels that visible bulges are formed on the boundary and is then carried-forward to the next pixel and included in the fractional value thereof. Instances of such prevention functions are described. This procedure gives a better reproduction of lines extending obliquely over the pixel raster.