Abstract: A method and a printing system are described capable of rendering more than 2 density levels at the device pixel level using precalculated rectangular screening tiles of finite size that define a spatially repetitive screening operation according to geometric clustered dot screen definitions for first, second and third separation screens that has the following characteristics: (A) the set of at least three separation screens is free of second order moiré; (B) the set of at least three separation screens consists of screens that have no internal moiré and/or screens that have a reduced sensitivity to amplification by process instability of any remaining level of intrinsic internal moiré; and (C) the screens have an optimized and balanced rosette structure leading to a reduction of visible patterning in overlays of the separation screens.

Abstract: A light emitting head for use in copiers or printers, the light emitting head having an illuminated length, e.g.

Abstract: An apparatus and method to condition the fuser surface of a fusing or transfusing apparatus for a toner based printing system is described. The apparatus and method integrate the functions of cleaning paper debris and residual toner from the fuser (or transfuse) surface on one hand and the application of a release agent such as silicone oil on the other hand using a single release agent impregnated web. The inventive device includes a release agent application roller and a cleaning roller where the outer surfaces and are selected in preferred embodiments for their respective wetting properties with respect to the release agent used. The fuser surface conditioning device increases the useful life for a fusing or transfusing roll or belt even when low amounts of release agent are applied to the fusing surface such that the amount of release agent that is transferred to the print media is in the range of 0.5 to 5 mg/A4 sheet.

Abstract: A method and a printing system are described capable of rendering more than 2 density levels at the device pixel level using precalculated rectangular screening tiles of finite size that define a spatially repetitive screening operation according to geometric clustered dot screen definitions for first, second and third separation screens that has the following characteristics: (A) the set of at least three separation screens is free of second order moiré; (B) the set of at least three separation screens consists of screens that have no internal moiré and/or screens that have a reduced sensitivity to amplification by process instability of any remaining level of intrinsic internal moiré; and (C) the screens have an optimized and balanced rosette structure leading to a reduction of visible patterning in overlays of the separation screens.

Abstract: An apparatus and method to condition the fuser surface of a fusing or transfusing apparatus for a toner based printing system is described. The apparatus and method integrate the functions of cleaning paper debris and residual toner from the fuser (or transfuse) surface on one hand and the application of a release agent such as silicone oil on the other hand using a single release agent impregnated web. The inventive device includes a release agent application roller and a cleaning roller where the outer surfaces and are selected in preferred embodiments for their respective wetting properties with respect to the release agent used. The fuser surface conditioning device increases the useful life for a fusing or transfusing roll or belt even when low amounts of release agent are applied to the fusing surface such that the amount of release agent that is transferred to the print media is in the range of 0.5 to 5 mg/A4 sheet.

Abstract: A light emitting head for use in copiers or printers, the light emitting head having an illuminated length, e.g.

Abstract: The present invention relates to a method of preparing print ready data. The method is adapted for converting first device specific print data for printing a multicoloured print job calorimetrically adapted to a first printing device or set of colorants, e.g. inks or toners, to print data calorimetrically adapted for a second printing device or set of colorants. The method comprises processing the data equally fast or faster than the print speed. The latter may be performed during printing, such that no halts are needed in between print jobs and the printing speed is mainly determined by the speed of the printing engine. The invention also relates to a corresponding system.

Abstract: A method and system for reproducing an image on a carrier, the method includes: generating a conjoined first and second sub-image, each representative for a portion of the image; defining an overlap region where both sub-images give a contribution to the internal optical density of the carrier; dividing the overlap region in a partition of microdots; establishing for each sub-image a peripheral edge in the overlap region; increasing the contribution by the first sub-image from the peripheral edge of the first sub-image to the peripheral edge of the second sub-image; and assigning to at least one microdot an intermediate microscopic density different from a minimum or maximum microscopic density of microdots; wherein the contribution increases the microscopic density of the microdots by density steps smaller than half the difference between the minimum and maximum microscopic densities of the microdots.

Abstract: For the reproduction of originals, images are generated on an image carrier, for example by printing. The imaging device that generates the image is usually not capable to cover at once the complete image area on the carrier. If the device is capable to cover the full width of the image area, the image may be generated line by line. Devices not having this capability will generate a first portion of an image line on the carrier. An adjacent second portion of the image line is then generated by another imaging device or after a period of time by the imaging device that generated the first portion. The region where the first and second portion meet on the carrier may cause visual artefacts on the final reproduction due to spatial misregistration of the adjacent line portions. This problem is solved by dividing the image in adjacent sub-images having an overlap zone on the carrier.

Abstract: For the reproduction of originals, images are generated on an image carrier, for example by printing. The imaging device that generates the image is usually not capable to cover at once the complete image area on the carrier. If the device is capable to cover the full width of the image area, the image may be generated line by line. Devices not having this capability will generate a first portion of an image line on the carrier. An adjacent second portion of the image line is then generated by another imaging device or after a period of time by the imaging device that generated the first portion. The region where the first and second portion meet on the carrier may cause visual artefacts on the final reproduction due to spatial misregistration of the adjacent line portions. This problem is solved by dividing the image in adjacent sub-images having an overlap zone on the carrier.

Abstract: For the reproduction of originals, images are generated on an image carrier, for example by printing. The imaging device that generates the image is usually not capable to cover at once the complete image area on the carrier. If the device is capable to cover the full width of the image area, the image may be generated line by line. Devices not having this capability will generate a first portion of an image line on the carrier. An adjacent second portion of the image line is then generated by another imaging device or after a period of time by the imaging device that generated the first portion. The region where the first and second portion meet on the carrier may cause visual artefacts on the final reproduction due to spatial misregistration of the adjacent line portions. This problem is solved by dividing the image in adjacent sub-images having an overlap zone on the carrier.

Abstract: A fixing device and method for transfusing toner on a receptor material is disclosed. Particularly, the fixing device comprises a heated transfuse member having an outermost layer of a material selected from the group of polyorganosiloxanes, fluorosilicones, fluoro-elastomers, phenylsilicones, and mixtures or hybrid compositions thereof. In operation, this outermost layer releases an amount of release agent corresponding to an amount of release agent of 0.05 mg per printed side of A4 paper or below, measured on NopaColor 100 gsm paper at an operating temperature for the transfuse member of 120 degrees Centigrade. Preferably, this outermost layer has a peel force, being measured according to Finat No. 3, with tape TESA 4163 at a peeling speed of 30 cm/min, above 7 N/m.

Abstract: A fixing device and method for transfusing toner on a receptor material is disclosed. Particularly, the fixing device comprises a heated transfuse member having an outermost layer of a material selected from the group of polyorganosiloxanes, fluorosilicones, fluoro-elastomers, phenylsilicones, and mixtures or hybrid compositions thereof. In operation, this outermost layer releases an amount of release agent corresponding to an amount of release agent of 0.05 mg per printed side of A4 paper or below, measured on NopaColor 100gsm paper at an operating temperature for the transfuse member of 120 degrees Centigrade. Preferably, this outermost layer has a peel force, being measured according to Finat No. 3, with tape TESA 4163 at a peeling speed of 30 cm/min, above 7 N/m.

Abstract: The device includes an endless fixing member urged into contact with an endless counter member to form a fixing nip therebetween through which a receiving material path extends. A cleaning member having a tacky surface is in contact with the surface of the fixing member to remove debris therefrom. Polymer material particles are applied to the cleaning member to render the surface tacky. A radiant heating device heats the polymer material particles on the cleaning member surface to render the surface tacky prior to contact of the cleaning member surface with the fixing member surface. Debris, especially paper dust, can thereby be reliably removed from the fixing member.

Abstract: An apparatus is provided for reproducing a continuous tone image by imagewise application of toner particles to a substrate comprising: means for partitioning a surface of the substrate in a plurality of disjunctive microdots; means for applying to at least one microdot at least two types of toner, having substantially the same chromaticity. Preferentially, for each toner type a large majority of microdots within a region comprising adjacent microdots, is supplied with either a high or low amount of toner, whereas the other microdots are supplied with a medium amount of toner, and more preferentially for at least one toner type the region comprises at least one microdot supplied with a high, another with a low and another with a medium amount of said toner. In a preferred embodiment the minimum number (N) of types of toner particles used in the apparatus depends on the volume average size of the toner particles used.

Abstract: A single pass printer, having a printing width (PW) is provided or printing a toner image on a substrate, the substrate having a width (WS) and a length (LS), wherein, i) a number n, equal to or larger than 2, of printing engines, each containing a toner transferring element with a longitudinal axis (width (WPE)) smaller than the printing width (PW) are present, and at least two of the n printing engines, each containing a toner transferring element with a longitudinal axis in the direction of width (WPE), are located so that the longitudinal axis do not coincide. Preferably the printing engines are electro(stato)graphic engines, especially Direct Electrostatic Printing (DEP) engines or electrophotographic engines.

Abstract: A DEP device is provided that comprises a printhead structure with control electrodes in combination with printing apertures and a magnetic brush assembly delivering a cloud of toner particles in the vicinity of the printing apertures, wherein the toner particles are, together with magnetically attractable carrier particles part of a multi-component developer further and the magnetic brush comprises a magnetic core rotating at a speed equal to or higher than 500 rpm (rotations per minute) and a sleeve rotating at a speed equal to or lower than 10 rpm (rotations per minute).

Abstract: A method and device for printing a reproduction of an image by using toner particles, in which digital image data of at least two density separations of the image is obtained for forming at least two sub-images. The image data of a first sub-image of the sub-images is provided to a printing station containing toner particles with a particular chromaticity and a particular optical density. Then, the first toner particles are applied in an image-wise manner on an image receiving member for forming a first toner image in correspondence with the image data. Thereafter, on the same printing station and using second toner particles having a chromaticity substantially equal to the particular chromaticity and an optical density substantially equal to the particular optical density, the image data is again provided and the toner particles are again applied for bringing at least one second toner image, corresponding to a second sub-image, on the image receiving member in register with the first toner image.

Abstract: A single pass printer, having a printing width (PW) is provided for printing a toner image on a substrate, the substrate having a width (WS) and a length (LS), wherein, i) a number n, equal to or larger than 2, of printing engines, each containing a toner transferring element with a longitudinal axis (width (WPE)) smaller than the printing width (PW) are present, and at least two of the n printing engines, each containing a toner transferring element with a longitudinal axis in the direction of width (WPE), are located so that the longitudinal axis do not coincide. Preferably the printing engines are electro(stato)graphic engines, especially Direct Electrostatic Printing (DEP) engines or electrophotographic engines.

Abstract: A method is disclosed for rendering monochrome or colored continuous tone images by a system having restricted continuous tone rendering capabilities, such as electrographic printers capable of printing more than two density levels on each addressable micro dot. A method for preferred halftone dot growth is described, starting from isolated dots arranged along base lines and auxiliary lines, evolving to high density lines along the base lines and approximating full continuous tone rendition for high density regions. Preferred arrangements for the orientation, spacing and absolute location of the base lines and auxiliary lines are disclosed and a method to generate preferred arrangements. A moire free combination of three halftone images is described for the reproduction of color images. A method to select a restricted set of energy levels to obtain linear reflectance response is disclosed. Halftone cells are arranged in supercells to improve the density resolution of the system.