Agfa Gevaert Nv

Agfa-Gevaert

Xeikon N.v.

Afga-Gevaert Nv

Luc K Van Aken

Serge M Tavernier

Robert F Janssens

Luc Van Goethem

Marc A De Niel

Jan A Zwijsen

Bert Vackier

Eric Van Echelpoel

Constant Bogaerts

Henri Goossen

Guido Vital Desie

Leo N Vackier

Jacques Victor Leonard

Ludo Joly

William Constant Waterschoot

Paul H Leys

Andre Van Geyte

Bart Diels

Karel Van Eynde

Karel Van Den Eynde

Marcel F Verbeek

Frans Backaljauw

Paul Frans Janssen

The apparatus includes an endless belt, an imaging station, a number of developing stations, and a number of transfer stations. A controllable belt drive drives the endless belt along a path through the imaging station, the developing stations and the transfer stations. A preformed timing mark is carried on the belt and a sensor is provided for sensing the passage of the timing mark past a sensing position. A control device controls the belt drive to run at a constant speed and controls the speed of the belt in response to the sensing of the timing mark. The maintenance of a constant belt speed can be more reliably assured.

Apparatus for forming multiple toner images in register with each other

Electrostatographic printing apparatus with a recording member in the form of an endless belt (26), and an air bearing (50) for guiding such belt along an endless path, which air bearing includes two belt-supporting end sections (53, 54) with a certain circumferential size, arranged for producing supporting air cushions for supporting both marginal portions of the endless belt (26) while the belt (26) is angularly wrapped about the sections (53, 54), an intermediate section (59) located between such end sections (53, 54) for providing support for the belt (26) if a central portion thereof would tend to become displaced exaggeratedly inwardly of the bearing (50), and two air cushion relief sections (61, 62), each one located inwardly adjacent to a corresponding end section of the bearing (50), and having a circumferential size which is smaller than that of said end sections (53, 54).

Electrostatographic printing apparatus with endless recording belt

A plurality of electrostatic images are formed on a moving tensioned belt formed with an electrically conductive base having a non-conductive image-carrying surface layer. The images are developed by passing the belt through toner development stations, each of which includes a development unit including a magnetic roller and a backing member, in opposed position to the magnetic roller, over which the belt passes. Under non-ideal conditions, the image quality in terms of image density and uniformity of image density and rendition of sharp image transitions, is substantially improved by applying an alternating electrical field between the magnetic roller and the belt, with a peak-to-peak voltage greater than 800 volts.

Method of using an image forming apparatus

An image forming apparatus is used, in which an electrostatic image formed on a moving image forming belt is developed by AC development. Where the image forming belt moves at a speed of v.sub.p mm/s, the cleaning potential is V.sub.cl volts, and the AC bias frequency is f kHz, the function Z satisfies the following equation: ##EQU1## Images substantially free of background development are thereby obtained.

Method of developing an image in an image forming apparatus

A fusing station (25) of an electrographic apparatus fixes in a single pass a duplex resinous powder color image (8, 18) to a support material in sheet-form (9) as the sheet is moved over a predetermined path (7). The station comprises two heated fixing rollers (1, 11), rotating in contact with each other, driving means to rotate the fixing rollers, pressing means for applying a meshing force between the fixing rollers, heating sources (4, 14) which have substantially identical characteristics. Both fixing rollers comprise a heat conducting core (3, 13) and a resilient covering (2, 12) which by the pressure between both rollers forms a heating nip. A symmetrical fixing operation on both sides of the sheet is provided. Hereto, the fixing rollers have a substantially identical construction, are positioned symmetrically to the path of the sheet and rotate synchronously to the advancement of the sheet.

Single-pass fusing of sheet-fed multi-layer duplex copies

A DEP device is provided that comprises a back electrode (105), a printhead structure (106), an array of printing apertures (107) in the printhead structure (106) through which a particle flow can be electrically modulated by a control electrode (106a), a toner delivery means (101), presenting a cloud (100) of dry toner particles in the vicinity of the apertures (107), characterized in that the toner cloud (100) is formed in the vicinity of the apertures (107) by means of a gas stream. The toner cloud is formed by detaching toner particles from a charged toner conveyer by the gas stream, or by forming a fluidized bed of toner particles.

Direct electrostatic printing device which uses a gas stream to provide

A fusing station of an electrographic apparatus fixes in a single pass a duplex resinous powder color image to a support material as the support material is moved over a predetermined path through the fusing station. The fusing station employs a symmetrical fixing operation on both sides of the support material. The fusing station applies hot air to both sides of the support material in substantially equal flows. The hot air is heated by heating sources with substantially identical operational characteristics such that the flows of hot air are heated to substantially equal temperatures on both sides of the support material.

Single-pass fusing of multi-layer duplex copies

A heat and pressure fusing device (10) for fixing toner images to a receptor support, the device having a fixing (12) and a pressure (13) roller rotating in contact with each other, wherein the fixing roller has a diameter larger than 70 mm.

Heat and pressure fusing device

Drum-type imagesetter for producing an image on a flexible sheet of radiation-sensitive material, which comprises retaining bars (62) for retaining a sheet in a substantially cylindrical configuration, and an exposure system (70) for image-wise exposing the curved sheet, the radial position of the sheet retaining bars (62) being controlled by adjustment screws (49, 50) allowing different drum diameters to be set.

Drum-type imagesetter with variable diameter

Rotating drum (10) imagesetter for producing an image on a flexible sheet of radiation-sensitive material, wherein a sheet (20) is held on the inside surface of the drum (14), and the exposure means (25) his located inside the drum.

Imagesetter with rotating internal drum

The present invention provides an assembly of a first panel formed with at least one insertion notch extending inwardly from at least one panel edge and a second panel carrying at least one projecting tab extending outwardly of at least one of its edge and fitting in one of the notches. The tab has on at least one of its sides a shoulder defining an edge which is located along the projecting length of the tab at a position intermediate the free edge of the tab and its base, which usually coincides with the edge of the panel from which it projects. The shoulder edge is in abutting contact with a region of the first panel adjacent the insertion notch in the first panel in which the tab fits and functions to maintain the associated edge of the second panel out of contact with the first panel so that the relative positions of the panels is determined by such abutting contact and is independent of other factors, such as the precise linearity of the panel edge. Multiple tabs can be provided on the same panel and in the same plane for insertion into corresponding notches.

Plate assembly

The present invention provides an assembly of a first panel formed with at least one insertion slot and a second panel carrying at least one projecting tab extending outwardly of at least one of its edges and fitting in the slot. The tab has on at least one of its sides a shoulder defining an edge which is located along the projecting length of the tab at a position intermediate the free edge of the tab and its base. The shoulder edge is in abutting contact with a region of the first panel adjacent one of the insertion slot and thus maintains the associated edge of the second panel out of contact with the first panel so that the relative positions of the panels is determined by such abutting contact. The first and second panels can be positively secured together by means of an interconnection element, preferably in the form of an integral flange bent up from one of the panels, which is attached to one or both other panel by screws, bolts and nuts or similar attachment devices. The plane of an integral interconnection element should be displaced inwardly of the plane of the shoulder edge to prevent interference with the precise locating function of the shoulder edge.

Panel assembly

An apparatus for forming a color image by transfer of at least one distinctively colored color image from a corresponding support therefor onto a single carrier support using a transfer cylinder for each color image for receiving on its periphery in a fixed location the image-carrying support and transport means carrying a register strip provided with register holes and attached to the leading end of the carrier support along a path tangential to the transfer cylinder periphery, the transfer cylinder including registering pins movable radially thereon between a retracted inoperative position and an operative projected position projecting outside the cylinder periphery for engagement with the register holes as the register strip arrives at the cylinder. After registration, the image-carrying support and carrier support are pressed together progressively along their length to transfer the image to the carrier support. The sequence is repeated at the transfer cylinder for each color image. The movement of the register pins is controlled timed relation to the transport of the register strip by control means, preferably a cam.

Apparatus for the production of a colour image

An electrostatic latent image developing assembly having a first feed passage for feeding developing material in a first direction, a second feed passage for feeding the developing material in a direction opposite to the first direction. A helical feed screw in the first feed passage, a helical supply screw in the second feed passsage for supplying part of the developing material to a developing sleeve, a connection between both sets of adjacent ends of such feed passages for permitting the developing material to circulate between the passages, wherein the feed screw and supply screw are disposed in parallel relation and the supply screw is provided with buckets around its periphery, the supply screw having a helical blade for advancing developing material in the second feed passage axially thereof while the buckets move the material circumferentially. Preferably, the radius of the helical blade reaches to at least one-half the depth of the buckets.

Growing community of inventors

Kuringen, Belgium

Luc K Van Aken