Agfa Gevaert Nv

Agfa-gevaert

Texas Instruments Corporation

Xeikon Manufacturing N.v.

Other

Agfa Corporation

Xeikon N.v.

Xeikon International N.v.

Dirk K Broddin

Serge M Tavernier

Frank A Deschuytere

Guido Vital Desie

William E Nelson

Robert F Janssens

Ludo Joly

Jacques Victor Leonard

Hilbrand Leopold Van Den Wijngaert

Peter Eelen

Werner F Heirbaut

Mario Verbruggen

Jean-Pierre J Slabbaert

Venkat V Easwar

Stefaan K De Meutter

James M Florence

Leon L Vermeulen

Paul A Delabastita

Vadlamannati Venkateswar

Ludo Verluyten

Marc Herregods

Michel Boulonne

Paul Marksch

Maarten Achten

Vadlammanti Venkateswar

James St Clair

Herman Van De Straete

Kurt Mampaey

Stefaan Lippens

Eric Van Weverberg

Eric Soulliaert

Hans Vangenechten

Kris Nuyts

Paul Vrindts

Wouter Boeckx

Danny Smolders

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 moir&#xe9;; (B) the set of at least three separation screens consists of screens that have no internal moir&#xe9; and/or screens that have a reduced sensitivity to amplification by process instability of any remaining level of intrinsic internal moir&#xe9;; and (C) the screens have an optimized and balanced rosette structure leading to a reduction of visible patterning in overlays of the separation screens.

Multilevel clustered dot screening method with improved detail and reduced image noise

A light emitting head for use in copiers or printers, the light emitting head having an illuminated length, e.g. a print width or copy width, and including a rigid carrier structure provided from a bulk material that spans at least the illuminated length of the head, the bulk material having a coefficient of thermal conduction larger than 100 W/mK and a coefficient of thermal expansion; a plurality of blocks of light elements arranged in a longitudinal array, the blocks having a coefficient of thermal expansion, each of the blocks of light elements having a first and a second surface, each of the blocks of light elements including a plurality of light-emitting elements exposed on a first surface on the block, the plurality of blocks being physically attached to the carrier structure by a conductive adhesive at substantially the second surfaces, and wherein the bulk material has a coefficient of thermal expansion that differs from the thermal expansion coefficient of the block material by a maximum of 5*10/K.

Light emitting array for printing or copying

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.

Apparatus and method for release agent application and cleaning of a fuser surface using a release agent impregnated web

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.

Screening method for overlapping sub-images

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. Within this overlap zone two sub-images will be generated on top of each other for reproducing the original image in that zone, thereby reducing or avoiding the artefacts. According to one method, the resulting optical density of the first and second sub-image is reduced within the overlap zone as the outer edge of the sub-image in the overlap zone is approached. The density reduction may be achieved by reduction of the microscopic density of individual microdots or by reduction of the dot percentage or by a combination of these techniques.

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.

Fixing device and method for transfusing toner

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.

Fixing device for fixing toner images onto a receiving material

Method for stable electro (stato) graphic reproduction of a continuous tone image

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.

Printer for large format printing

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).

Direct electrostatic printing apparatus having a magnetic brush with a

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.

Method for printing continuous tone images with high density resolution

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.

A method is described to control the maximum density and the pixel profile of microdots produced by a binary or multilevel electrophotographic device. In various embodiments, from the maximum development potential. The working point of the device is established by imposing a relation between charge level, discharge level and saturation voltage level of the photosensitive element. This allows to achieve consistent output densities, irrespective of the environmental parameters, such as relative humidity and temperature.

Process control of electrophotographic device

In classic optical rendering systems, the spot, illuminating a microdot on the photosensitive medium, is designed to overlap with neighboring microdots, typically having an overlap of 1.7 times the pitch of the microdots, for a luminous intensity of 1/e.sup.2 the highest intensity. A 'sharp' photosensitive medium, such as a photographic film used in graphical applications, generates a binary circle, obtainable by thresholding. The area of such a circle is too large, which results in higher dot gain. Many systems, such as electrographic systems, do not behave as a 'sharp' medium. If intermediate energy levels are used, in order to obtain continuous tone or multiple density levels, thresholding behavior may be avoided by appropriate choice of energy levels. Such a different sensitometry results in specific requirements for the energy distribution for each microdot. A square shaped uniform energy distribution within the space allotted to each microdot, allows for multiple density levels, without severe sensitometric requirements.

Uniform exposure of photosensitive medium by square intensity profiles

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.

Clustered dot and line multilevel halftoning for electrographic color

Growing community of inventors

Edegem, Belgium

Dirk K Broddin