Abstract: A top panel of a copying machine is provided with a tray or like means forming a cavity recessed from bordering top surface areas for collecting staples removed from stapled bundles of originals to be copied, and a rigid finger protrudes freely into the cavity for removing the staple from a bundle of originals suitably placed onto and moved over the appliance. The finger has its top surface largely formed flat and tapered to an upturned narrowed tip that projects slightly above the plane of the adjacent top surface areas. By placing a stapled bundle of sheets on the appliance with the staple located ahead of the finger and the bent-over legs of the staple facing upward and then manually moving the bundle over the finger, the tip of the finger can engage between the staple and the sheets, and upon further movement of the bundle the tapered forward portion of the finger pulls the staple out of the sheets.

Abstract: The copying apparatus comprises a document feeder having transport paths for simplex and duplex originals, and at least two copy transport paths for feeding finished copies from the image transfer means to a collection station. One copy transport path is operable to deliver a duplex copy fed therethrough to the collection station with the first printed side facing downwards, and the other copy transport path is operable to deliver a duplex copy to the collection station with the last printed side facing downwards. The copying apparatus further comprises selection means for selecting the desired type of copies, a detector in the original transport path for determining whether an original fed therethrough is simplex or duplex and control means for regulating the transport of copy sheets dependent on the type of originals detected by the detector and the type of copies selected with the selection means.

Abstract: Colored magnetically attractable toner powder for the development of latent electrostatic or magnetic images consists of particles each comprising a magnetically attractable core, preferably spherical, formed of particulate magnetically attractable material or of a dispersion of such material in a binder, a masking layer enveloping the core and containing binder mixed with light-reflecting pigment of submicron particle size, and coloring material applied in and/or onto the masking layer. Processes for preparing the toner powder are disclosed, and a process for developing electrostatic or magnetic latent image patterns by its use.

Abstract: A reusable electrophotographic element comprising a photoconductive layer containing sensitized zinc oxide particles and first and second binding agents that are incompatible is produced by employing as the first binding agent a macromolecular compound that has a higher affinity to zinc oxide than the second binding agent, is largely deposited on the zinc oxide, has an average molecular weight of at least 12,000 and is present in the photoconductive layer in an amount of 1.5 to 9% by weight calculated on the zinc oxide, with the second binding agent present in substantially larger amount. The photoconductive layer is formed of agglomerates of zinc oxide particles substantially enveloped in the first binding agent, which agglomerates have a diameter of between 2.5 and 6 .mu.m and are stuck together by portions of the second binding agent, thus providing a substantially porous photoconductive layer having a negative charge density of at most 1 m Coulomb per m.sup.2.

Abstract: Powder images are transferred and fixed onto receiving supports of absorbent material such as paper so as to form copies of fine quality without need for heating or for applying solvent vapors to make the images sticky, by forming each powder image of water-absorbent powder particles that soften on absorbing water, transporting the powder image on a resiliently deformable, hydrophobic support surface to a transfer zone for transfer under pressure onto the receiving material, and in a treatment zone spaced ahead of the transfer zone covering the hydrophobic support surface and the powder image with water and directly afterward squeegeeing water from the wetted image and support surface.

Abstract: Vibrations in a taut flight of a photoconductive belt moving through the image projection zone or another processing zone of an electrostatic copying machine are suppressed by means of a closed flat plate surface disposed parallel to the belt flight at a small distance therefrom, such as a distance of 1 to 2 millimeters.

Abstract: A corona device comprising a multiplicity of electrode pins embedded in a body of insulating material has each pin projecting from two sides of the insulating body and has this body disposed between two conductive elements, or electrodes, which are connectable to the opposite poles of a voltage source. The ends of each pin are in the electric field between the electrodes at locations between which a high potential difference is present, so that a corona discharge may develop between each end of a pin and the related electrode. The corona device may also comprise provisions for inhibiting deterioration of the pin ends subject to positive corona discharge, and/or for counteracting the positive potential so that no positive corona discharge will occur.

Abstract: A slit exposure device movable back and forth in a path parallel to a stationary original for projecting an image of the original in linear portions onto a moving photosensitive element in belt form has a lamp for illuminating the original, an optical system, at least two interconnected belt deflecting rollers and a drive for moving these rollers with the optical system along and parallel to the object plane. At least one of the deflecting rollers deflects the photosensitive element counterclockwise and at least one of them deflects it clockwise from its original direction of movement, and the optical system projects the image in linear portions onto the photosensitive element at a location within the path formed by and between the deflected portions of the photosensitive element.

Abstract: In a copying machine comprising a photoconductive belt (5) that is moved past a number of processing stations in order to make copies, the belt (5) is divided relative to a reference point into a plurality of imaging sections each of which is capable of copy formation. Each imaging section is subject to deterioration as a function of the number of times a copy has been made with the use of that imaging section. A control circuit (100, 110) is provided comprising a counter memory (102) that for each imaging section stores the number of copies made with the use of that imaging section. The control circuit (100, 110) further comprises means (103, 105, 106, 107) which, as a function of the count in the memory (102) for a particular imaging section, adjust one or more of the processing stations when a processing station is acting on that imaging section.

Abstract: In an ultrasonic system for detecting and distinguishing between superimposed and single sheets moving along a transport path, the frequency of the ultrasonic source is kept tuned to the natural frequency of the total system so that the phase displacement detected when a sheet-like object is present between the source and the ultrasonic receiver represents characteristics of the object itself. When no sheet-like object is present the receiver and the source are connected in a feedback circuit producing a certain natural frequency comparable to that which occurs with proximities between a microphone and a loud speaker, and the frequency of an oscillator is tuned to this natural frequency. When a sheet-like object is present the tuned oscillator frequency is applied to the ultrasonic source and its phase is compared with the phase of the ultrasonic signal at the receiver.

Abstract: A polygonal mirror is provided which presents a plurality of mirror surfaces arranged about an axis of rotation with all the mirror surfaces at the same inclination relative to that axis. The mirror comprises a reflecting foil tightened over a plurality of supporting elements arranged about the axis of rotation. Equal angles between the mirror surfaces are obtained by employing cylinders as the supporting elements. The cylinders all have the same outside diameter, and are placed together with each touching two neighboring cylinders and each in contact with a central cylinder the axis of which coincides with the axis of rotation.

Abstract: A copying apparatus which automatically produces duplex copies in logical page sequence from simplex originals comprises transport paths for conveying originals to and from a copying position, imaging means for producing an image of an original onto a copy sheet, a first hopper to collect single-sided copy sheets, a second hopper to collect duplex copies and delivery means for delivering the duplex copies into the second hopper. The delivery means comprises a first delivery path and a second delivery path, and a detector in the transport path of the originals determines whether the number of originals to be copied is even or odd, thus causing the duplex copies to be delivered through the first or the second delivery path, depending on whether an even or an odd number of originals has been detected by the detector. The apparatus disclosed is also suited for programmed production of simplex copies from simplex originals, duplex copies from duplex originals, and simplex copies from duplex originals.

Abstract: A reprographic camera for exposing an original to illumination that is passed through an optical system to light-sensitive material is provided with a holder having at least two mounting surfaces onto each of which an original can be fitted, and which is rotatable about an axis perpendicular to the optical axis of the optical system so that the holder can be set in a plurality of positions in each of which one of the mounting surfaces faces the optical system. One of the mounting surfaces is located at a greater distance than another from the axis of rotation of the holder so that the respective active positions of these surfaces are at different distances from the objective of the optical system, thus providing different reproduction ratios.

Abstract: An electrographic apparatus by which powder images corresponding to electrostatic images can be formed on receiving material and fixed onto the receiving material by heat and contact is provided with a control system which regulates the quantity of receiving material transported to the fixing device per unit of time so as to keep the heat content of heated surface elements of the fixing device suited for the heat capacity of the receiving material even when receiving materials of different weights are used. The control system can also make the formation of either electrostatic or powder images dependent upon the existance of heat content in the fixing device suited for the heat capacity of the receiving material.

Abstract: A corona device suitable for use in electrophotographic apparatus to provide a uniform charge on photoconductive material comprises as the ion-generating means a multiplicity of electrode pins, all of the same diameter, which are provided at the same mutual spacing from one another in a body of insulating material from which all the pins project to the same extent, with the pins limited to a diameter between 10 and 100 microns, a mutual spacing of between 0.3 and 2.5 mm, a projecting length of between 0.7 and 3 mm, a length to diameter ratio of between 10 and 300 and a spacing distance to diameter ratio of between 4 and 250. The electrode pins are formed from lengths of a suitable conductive wire which are laid at the required mutual spacing and soldered to and between conductive strips to form an electrically conductive unit that is embedded in a cast body of the insulating material with free ends of the wire lengths projecting to the required extent.

Abstract: A reproduction apparatus comprises a rotatable drum having trained over its circumferential surface a length of finite belt that extends and is transportable back and forth between two supply reels inside the drum and is impressible with image information to be transferred to receiving material at a transfer station adjacent to the drum surface. During transport of the belt in either direction relative to the drum surface the drum is held at a peripheral velocity which depends upon the direction of the belt transport and, considering both magnitude and direction, is equal to a given processing velocity of the belt relative to the transfer station minus the velocity of transport of the belt over the drum surface. Thus, the transport of the belt relative to the transfer station is always in the same direction and of the same magnitude, whether the belt is being transported from one reel to the other or back from the other to the one reel.

Abstract: A system for feeding originals one by one from a stack of them to the illumination station of a copying machine and finally back to the top of the stack, so as to enable automatic production of sets of correctly sequenced copies of double-sided and/or single-sided originals, comprises a holder for stacking originals, means for removing the bottom original from the holder, a first transport path for transporting the original from the holder to the illumination station via its inlet side with the side of the original that faced downward in the holder in position for copying, means for transporting the original from the exit side of the illumination station into a reversing path and from the reversing path again via the inlet side to the illumination station, and means including at least part of the reversing path and a final transport path for returning the original from the exit side of the illumination station to the holder and placing it in its original orientation on top of the stack.

Abstract: In an apparatus for copying sheetlike originals, wherein a transport system feeds originals from a positioning surface onto an exposure plate and from the latter after exposure to a receiving tray, the positioning surface presents at least two distinct areas upon each of which an original can be laid ready to be fed in for copying and each area is bordered by a lateral arrest so that plural originals laid ready in the areas and against the arrests will be fed together to exact positions on the exposure plate for copying on one sheet of receiving material in one copying run of the apparatus. A system of open-front trays for piles of originals, each aligned with one of the positioning surface areas, facilitates the laying of originals in ready position. A control system responds to sensed presence of a complete set of originals in ready position to start a run.

Abstract: A holder for electrographic developing powder comprises an oblong outlet opening for the powder and has the opening covered by a membrane and by a slide valve which is movable along channels bordering the opening and is provided near one of its ends with a cutting device that cuts the membrane as the slide valve is moved from a first position closing off the opening to a second position not covering the opening. The holder comprises a flexible end portion that can be contracted by being pinched in a direction substantially parallel to the plane of the slide valve, and from which projections extend laterally for engagement with notches in guides that support the holder over a powder reservoir. The cutting device is moved toward the flexible end portion as the slide valve is moved from the first to the second position.