Abstract: A device for fixing or transferring and fixing a powder containing thermoplastic resin on to a receiving material under the influence of pressure and heat, in which device the fixing member in pressure contact with the powder during the fixing of the powder image is provided with an outer covering consisting mainly of silicone rubber. The silicone rubber is the reaction product of polyorganosiloxane bearing Si--H groups and polyorganosiloxane which bears Si--(CH.dbd.CH.sub.2) groups and which on average contains between 40 and 1000 monomeric units per polymer chain, bears 1.5-4 terminal vinyl groups, bears at most one non-terminal vinyl group per 80 monomeric units and contains at most 2% Si atoms in the form of SiO3/2 or SiO4/2 units. The thickness of the silicone rubber covering is preferably less than 500 micrometers.

Abstract: Coding of digital data corresponding to a dithered image. The digital pixel values determined by comparison with a given threshold value of the dither matrix are combined to form a string. A string of this kind is formed for all the threshold values of the dither matrix. Strings found which are built up largely of a given pixel value are immediately converted into strings built up entirely of that pixel value, and are coded collectively. The other strings found are coded individually by comparing each of them with a set of standard strings and replacing them by the most similar standard string.

Abstract: A regulating device for copying machines used in forming an image of an original on an image carrier and transferring the formed image onto a receiving material in which the relative position of image and receiving material with respect to each other before the iamge transfer can be adjusted. The copying device is provided with a margining means which in response to said adjustment is automatically adjusted for rendering image-free all the zones of the image carrier in which image and receiving material do not coincide during the image transfer, so as to prevent contamination with image-forming material and the occurrence of undesired deposition of image-forming material on the image receiving material.

Abstract: A fixing device for fixing a powder image on a receiving sheet in a fixing nip formed by a fixing roller and a pressure roller which has a lower flexural stiffness than the fixing roller. These rollers are pressed against one another by a stationary cushion filled with compressed air and pressing against the pressure roller in a pressure zone situated opposite the fixing nip.When the pressure roller and the fixing roller are driven, tangentially directed frictional forces are exerted on the pressure roller that causes the pressure roller to deflect against a curved support surface which limits the deflection. The pressure roller deflected in the operative position causes a receiving sheet fed through the fixing nip to be stretched in a direction transversely of the direction of conveyance to eliminate any bubbles or corrugations in the receiving sheet.

Abstract: The entire dithered image to be enlarged/reduced is divided into contiguous relatively small areas, called input areas, and the pixel pattern of each input area is represented by (i) an average gray level characterized by a standard pixel pattern and (ii) the pixels deviating from the standard pattern. Every input area is imaged onto an output area according to the enlargement/reduction factor, whereby the output area is filled with a standard pixel pattern yielding the average gray level of the input area and extra pixels are added to the standard pattern for the deviating pixels of the input area on locations determined by linear transformation.

Abstract: Apparatus for binding a stack of sheets along one peripheral side by means of a strip of binder material having a heat activated layer of glue wherein removal device is provided for at least partial removal of the layer of glue in the zones of the web of binder material which, after cutting off a strip of a required length, are situated at the ends of the strip of binder material.

Abstract: In a device for conveying sheets wherein two conveying paths intersect, a moveable guide member is provided at the intersection such that in a first position it connects both parts of the first conveyor path while at the same time it disconnects both parts of the second conveyor path and in a second position has the reverse function on the first and second conveyor paths. Preferably, while the guide member is in the first position, a sheet can be conveyed form one part of the second conveyor path to one part of the first conveyor path via a third conveyor path which does not pass through the intersection. Similarly, while the guide member is in the second position, a sheet can also be conveyed from one part of the first conveyor path to one part of the second conveyor path via the third conveyor path.

Abstract: An image transfer and contact fixing device for a photocopier wherein a photoconductive drum presses against a transfer roller in a first contact zone to transfer a powder image from the photoconductive drum to the transfer roller, and a second contact zone wherein a pressure roller presses the receiving material against the transfer roller to transfer powder image from the transfer roller to the receiving material with a force greater than the force with which the photoconductive drum presses against the transfer roller. In a third contact zone, a cleaning roller presses against the transfer roller and exerts a compensating force on the transfer roller in such manner that the net resulting force experienced by the transfer roller at its axis is substantially zero.

Abstract: A method of generating a line part having a thickness D on a homogeneous raster, in which the raster points are arranged in a number of parallel lines, and in which the bit representation of the line part is stored in a word-oriented bit-map memory in the form of a large number of image points or pixels. The method provides for making a determination of the envelope of the line part and imaging the envelope on the raster points. Thereafter, determining the length of the section through the line part for successive raster lines, and placing the bit representation of said lengths in the bit-map memory at corresponding locations, so that the direction of the determined lengths corresponds to the word direction of the bit-map memory.

Abstract: Device for removing a staple from a stapled bundle of sheets by moving the bundle over a supporting element past a staple removing strip. The strip extends above the supporting element at a small acute angle therewith and is fixed to an arm which is rotatably mounted on a shaft positioned at the side of the strip facing away from the acute angle and below the supporting element. The strip is moved upwards when a stapled bundle of sheets, with the legs of the staple facing downwards, is fed between the supporting element and a wedge-like tapered end of the strip, which end presses onto the supporting element. When in this way the staple is positioned in front of the wedge-like tapered end of the strip, the bundle is pulled towards the strip, the end of the strip penetrates between the crown of the staple and the bundle and the staple thereafter is pulled out of the bundle. The pulled-out staple drops in a receiving tray formed beneath the supporting element.

Abstract: An optical imaging system for compensating for the image elongation inherent in the transferring and fixing process without introducing unsharpness in the image wherein the original moves in the object space relative to an optical system. The optical system projects an image of the original onto a light sensitive element which moves relative to the optical system at a different speed than does the original, such that the ratio of the two speeds determines the desired shortening of the image. In order to prevent image unsharpness, the angle between the image plane and the light sensitive element is determined as a function of the desired shortening of the image. This angle must be such that a point on the light sensitive element passes through the image space in the same time it takes a point on the original to pass through the object space.

Abstract: Raster image processor for filling a page-size raster image memory and for the conversion of the data stored in the raster image memory into a serial pixel-bit stream for a raster output scanner which includes a microprogrammable central processing unit; a raster image bus interface connected to a synchronous raster image bus system; a raster output scanner interface connected to the raster output scanner; an interface connected to the asynchronous bus system; and a synchronous raster image processor bus system connecting the microprogrammable CPU to the raster image bus interface to the raster output scanner interface, and to the interface which is connected to the asynchronous bus system.

Abstract: A multi-nozzle ink jet printer having an ink liquid supply system which is made up of a plurality of constant flow rate pumps. Each individual nozzle of the printer is connected to an associated pump. The pumps may be coupled to a common actuating mechanism such as a cam so that the flow rates of ink liquid through the different nozzles are kept at equal values irrespective of differences in the effective cross section of the nozzles.

Abstract: The surface parts of an image which is stored in the form of a bit-representation in a raster image memory may be filled with a surface pattern using the following steps: generating a bit-representation of the surface pattern defined uniformly over the entire image surface; generating a mask function, which gives a specific logic value to those raster points which are situated within the boundaries of the surface parts; generating a filling pattern by performing a logic operation on the bit-representation of the surface pattern and the mask function; and transferring the filling pattern to the raster image memory.

Abstract: A printing device for reproducing information having movable image-forming element with a dielectric surface. An image-forming station is provided in which a magnetic roller having a rotatable electrically conductive non-magnetic sleeve is disposed near the surface of the image-forming element. An electric field between the image-forming element and the magnetic roller is generated in accordance with an information pattern. An electrically conductive magnetically attractable toner powder is placed in the zone between the magnetic roller and the image-forming element during generating of the electric field. A magnetic field formed in the zone by stationary ferromagnetic knife blade disposed inside the magnetic roller sleeve and the blade is held between like poles of two magnets at an angle of between 70.degree. and 85.degree. to the tangential plane to the sleeve.

Abstract: An aging correction system for an LED array in a printer, in which each LED can be energized during a variable time and in which a light sensor, with which the relative light-output of each LED can be measured and compared with earlier measured values, is disposed near the array, and in which on the basis of these measured values a new correction value is determined.

Abstract: A device which can feed originals from a holder via a feed path to an exposure window using a cooperating pair of rollers and a conveyor device, the direction of movement of which can be reversed to allow returning of the originals via a discharge path to the holder. The pair of rollers is provided with a drive mechanism and a coupling belt which, during conveyance of an original to the exposure window, convey the original to and on the window in cooperation with the conveyor device and which stop the pair of rollers or reverse the direction of movement of the rollers during the conveyance of an original from the exposure window to the discharge path in order to inhibit feeding of the new original on one hand, and to position the new original on the other hand. There is a fixed time relation between the times at which the states of the movement of the pair of rollers and the conveyor device change.

Abstract: A belt tensioning device for use in a copying machine. The tension device includes two pairs of levers each lever having a first and second arm. A pair of floating rollers are provided to tension the belt by formation of loops in front of and behind, respectively, of an intermittent contact point between the belt and a pressure element moving at a different speed. Each floating roller is suspended in the ends of the first arms of the respective levers. The end of other arms of one pair of levers is connected to the end of the corresponding second arm of the other pair of levers by a tension spring system. One pair of levers has a larger transmission ratio than the other, so that the floating rollers return to their old positions after contact between the belt and pressure element.

Abstract: A method of generating and processing models of two-dimensional and three-dimensional objects in a computer and of reproducing the models on a display is presented. The models are created according to the user's instruction by means of geometric operations such as moving, rotating, enlarging, reducing and/or Boolean operations, such as connecting, forming points of intersection, forming points of differentiation, from elements whose shapes are already determined by data stored in or input into the computer. It is possible for these elements in turn to be constructed from elements of a lower hierarchical level. A menu of commands and a pointer whose position is controllable by the user through an inputting device are shown on the display outside the image of the model so that the user can select specific parts of the model and specific commands by marking the associated place on the display with the pointer.

Abstract: A digital proportional-integral controller for controlling the speed of a d.c. electric motor in a copying machine and synchronizing it with the speed of another motor in the copying machine. The proportional stage and the integral stage of the controller are each formed by an up/down counter which counts up or down depending upon the pulses of the actual speed signal and the reference signal. Logic circuits are provided for processing the speed signal pulses and the reference signal pulses before they are fed to the up/down counters. The controller also has an interface for a two-wire bus system over which data and commands for adjusting and varying the control parameters can be input.