Abstract: Electrostatographic image reproduction apparatus forms images of toner particles on a receptor material moving along a transport path. A rotatable contact roller contacts the receptor material while it has an electrostatically charged toner particle image on at least the adjacent surface thereof. The contact roller is selected from a receptor material transport roller, a guiding roller, and a reversing roller. Electrostatic charging device provide an electrostatic charge, having the same polarity as the charge polarity of the toner particles, on the surface of the contact roller before contact of the receptor material with the surface of the contact roller. Cleaning means remove any toner particles from the surface of the roller after release of the receptor material from the surface of the contact roller. Smudging of the toner image on the receptor material is reduced.

Abstract: A developing unit including a housing having an opening defining a developing zone, an applicator for applying particulate developer through the opening towards an electrostatographic image to be developed, and a paddle wheel for agitating developer within the housing, for scooping up developer from within the housing and projecting scooped-up developer towards the applicator. A hopper, located outside the width of the development zone supplies toner to the housing, and a primary spiral screw conveys developer from the hopper across the width of the development zone in one direction, while a secondary spiral screw receives developer from the primary spiral screw and conveys developer across the width of the development zone in an opposite direction. A passageway outside the width of the development zone enables the return of developer from the secondary spiral screw to the primary spiral screw.

Abstract: An electrostatographic printer for forming a toner image onto a receptor element comprises: (i) at least one toner image-producing electrostatographic station comprising rotatable endless surface means onto which a toner image can be formed, means for forming an electrostatic latent image on the endless surface means and a developing unit for depositing electrostatically charged toner particles onto the electrostatic latent image; (ii) means for conveying a receptor element past the image-producing station; and (iii) transfer means for transferring the toner image on the rotatable surface means onto the receptor element web. The printer is characterized in that the developing unit is selectively moveable between an operative position and a non-operative position while the endless surface means rotates. The printer avoids smudging on the first few prints produced by the printer.

Abstract: A receptor material conditioning apparatus and method for conditioning a moving paper web suitable for use in an electrostatographic printer. A heated drum reduces the moisture content of paper moving along a paper web path. A cooling box positioned downstream of the heated drum cools the moving receptor material. An electrometer determines the electrical condition of the paper before it leaves the apparatus. By conditioning the paper web, a higher yield of toner transfer in the subsequent electrostatographic printer can be obtained.

Abstract: An electrostatographic printer includes an imaging station for forming a latent electrostatic image on the surface of a drum, a toner development station for developing the latent image to form a toner image, and a toner transfer station for transferring the toner image onto a moving web. An image-fixing station for fixing the toner image on the web includes two pairs of radiant heat sources, the peak energy output wavelength of which lies in the non-visible part of the spectrum. The radiant sources may be located in hingedly mounted pairs of housings in such a manner that the housings may be moved into a closed position to shield the radiant sources from the web when the speed of movement of the web falls below a predetermined value. Thus, damage to the web when movement of the web stops is avoided.

Abstract: A recording head is described having mounted thereon M modules, each module comprising an array of N LEDs and associated drivers. The recording head comprises a carrier bar, and a carrier strip fixedly and electroconductively and thermoconductively secured to a surface of the carrier bar. The carrier strip comprises along one side thereof M spaced individual module carriers connected with the rest of said carrier strip by means of at least one frangible zone. M LED dies and associated driver module dies are fixedly secured to the surface of said M module carriers, each die containing an array of N linearly arranged LEDs. The array of N LEDs of each die overlaps the space between the spaced individual module carriers in order to come in abutting relationship with the end or ends of neighboring N LED arrays. In said LED array a module carrier on which a defective module is present can be replaced without damaging the adjacent modules.

Abstract: An electrostatographic printing process forms one or more colorless toner images in combination with at least one color toner image produced in an electrostatographic way on a receptor element. The information for producing an electrostatic latent image corresponding with the colorless toner image derives from a digital electrical signal representing (i) the spatial boundaries of the colorless toner image and (ii) the amount of deposited colorless toner per pixel. The receptor element is conveyed past a number of toner-image producing electrostatographic stations. At each image-producing station an electrostatic latent image is formed on a rotatable endless surface; toner is deposited on the electrostatic latent image to form a toner image on the rotatable surface, and the toner image is transferred from its corresponding rotatable surface onto the receptor element.

Abstract: An electrostatographic single-pass multiple station multi-color printer for forming an image onto a web has a plurality of toner image-printing electrostatographic stations. Each station has a drum onto the surface of which a toner image can be formed. An exposure station forms an electrostatic toner image line-wise on each drum surface. A corona device transfers the toner image onto the web, which is conveyed in succession past the stations in synchronism with the rotation of the drum surface. Register control apparatus provided for controlling the operation of each of the stations in timed relationship thereby to obtain correct registering of the distinct toner images on the web. The register control apparatus comprises an encoder driven by the displacement of the web to produce pulses indicative of web displacement, and a delay arranged to initiate the operation of subsequent stations after a predetermined web displacement, as measured by the encoder, has occurred.

Abstract: An electrostatographic printer is described for forming an image onto a moving web or sheet. The printer includes a number of toner image-producing electrostatographic stations having rotatable drums onto which a toner image can be formed. A development station forms a toner image on the drums. Drive rollers convey the web past the image-producing stations. Corona discharge devices transfer the toner image on the drum surface onto the moving web. The printer also has an air-conditioning device which has filters for removing dust and ozone from air leaving the environment of the image-producing station, a heat exchanger and a humidifier for adjusting the temperature and humidity of air leaving the environment of the image-producing station, and an inlet manifold for introducing a stream of the conditioned clean air into the environment of the image-producing stations.

Abstract: An electrostatographic single-pass multiple station (e.g. multi-colour) duplex printer is described for forming an image onto a web. The printer has at least three toner image-producing electrostatographic stations. Each station has a rotatable endless surface in the form of a photoconductive drum onto which a toner image can be formed. The printer also includes drive rollers for conveying the web in succession past the stations. Corona discharge devices transfer the toner image on each rotatable surface onto the web. The image-producing stations are arranged in two sub-groups, the drum of one sub-group forming a backing roller for the other sub-group, and vice-versa, thereby to enable simultaneous duplex printing.

Abstract: An electrostatographic single-pass multiple station multi-color printer for forming an image onto a web, eg of paper, is described. A plurality of toner image-producing electrostatographic printing stations each have a rotatable endless surface such as the photoconductive surface of a cylindrical drum onto which a toner image can be formed. The paper web is conveyed in succession past the printing stations. The speed and tension of the web is controlled while it is running past the printing stations. Guiding rollers which determine for the web wrapping angles of about 15.degree. about the drum surface. A corona device transfers the toner image on each drum onto the web. The corona device, the wrapping angles .omega. and the web tension are such that adherent contact of the web with the drum surface is such that the moving paper web controls the peripheral speed of the drum in synchronism with the movement of the web.

Abstract: A sheet imaging apparatus with a collector tray for receiving sheets discharged from the apparatus. The collecting tray has two stationary side-walls and a sheet-supporting back plate is driven in a reciprocating motion in a transverse direction, whereby two part-stacks of sheets may be produced that are individually accurately aligned by abutment against cooperating fixed abutments.

Abstract: A recording apparatus for linewise recording information on a moving photoreceptor, comprising a recording head with two staggered rows of pointlike radiation sources, wherein a shortcoming of prior art devices, namely stepwise deformation of a recorded line, caused by an incorrect registering of the even and uneven data dots, as a consequence of speed fluctuations of the photoreceptor upon recording, is overcome by controlling the recording of the data signals as a function of a signal from a speed sensor of the photoreceptor.

Abstract: In a recording apparatus comprising a recording head with a multiplicity of individually addressable and energizable point-like radiation sources arranged in staggered parallel rows for irradiating points across a moving photoreceptor, the driver circuits for the different rows of radiation sources are provided by identical chips. Each chip incorporates delay means capable of holding data-bit signals for a delay period before the signals are transmitted for energizing the associated radiation sources but is formed so that the delay means can be rendered inoperative by selecting one or other of different mode control voltage input points. The control chips for one row of the radiation sources are set in the delay-operative mode to compensate for the distance between the two rows of sources.

Abstract: A recording device for linearly recording information upon a moving photoreceptor using a recording head that can be manufactured more readily. The recording head is made with a plurality of modules, each module comprising LED chip means having an aggregate length (n) greater than the length (o) of the base plate of the module and projecting exteriorly of the module side edges, and a common integrated control circuit for all the LED's mounted on the base plate of a given module, the outputs of such circuit being connected by wire bonding to the respective LED's on the module.

Abstract: A recording apparatus for linewise recording information on a moving photoreceptor by means of a plurality of chips on each of which parallel sub-rows of uniformly spaced radiation sources are formed, wherein a shortcoming of prior art apparatus, namely the impossibility to use chips on which even one radiation source only is defect, is overcome.The apparatus comprises two parallel rows of radiation sources, each row comprising reserve radiation sources that are arranged with corresponding basic radiation sources of the other group in optical parallelism, and connection circuit means for establishing electrical contact with a basic and/or a reserve radiation source (FIG. 5).