Xerox Corporation

Versatec, Inc.

William A Lloyd

Keith E McFarland

Stephen David White

Lorin K Hansen

Robert P St John

Jack H Sayre

Edwardo D Lara

David D Thornburg

Richard J Gable

Herman Wong

Salvatore Barone

Angus H Whitaker

Gerald E Hooper

Kenneth E Smith

Willard J Patrick

In a device for producing an electrostatic image along a scan line of a recording medium by means of a recording device including an array of stylus electrodes arranged in a series of groups cooperable with a series of complementary electrodes, each of the stylus electrode groups cooperates with a portion of two adjacent complementary electrodes whereby writing is accomplished by imposing a charge pattern upon the recording medium in the region of a stylus electronic group when both the stylus electrode group and its cooperating pair of complementary electrodes are actuated contemporaneously. As each complementary electrode is actuated it induces a non-uniform residual potential distribution in the recording medium of a portion of the region of the next adjacent stylus electrode group. The electrostatic writing method comprises first perturbing a region of the recording medium by imposing a first non-uniform residual potential distribution on one portion thereof coextensive with the overlapping portion of a complementary electrode, then perturbing another portion of the same region by imposing a second non-uniform residual potential distribution thereon coextensive with the overlapping portion of another adjacent complementary electrode, wherein the first and second non-uniform residual potential distributions tend to cancel one another, and then writing a charge pattern upon the entire region.

Electrographic marking with modified addressing to eliminate striations

A preferred embodiment of the present invention is directed to a removal of a ghost image created during a processing of a film laminate medium by an electrographic plotter. A recording of an image on the film medium induces a ghosting potential over a developing station. The ghosting potential causes a spurious image to be developed by the developing station. The recorded image is created by depositing a charge on a dielectric layer of the film. A relationship exists between the deposited charge and the ghosting potential. By use of information known to the system, the ghosting potential may be estimated and reduced. A preferred method estimates the magnitude of the ghosting potential by use of the relationship between deposited charge and ghosting potential. A counteracting potential is applied to the system to reduce the ghosting potential over the developing station. The reduction of the ghosting potential substantially removes the ghost image created during the processing of the film laminate.

Film ghost removal in electrographic plotters by voltage bias of the

A liquid developing apparatus is provided for developing, with a liquid developer or toner, an electrographic latent image formed on an image bearing, charge retaining surface of a moving recording medium and thereafter wiping excess developer from the medium surface. The apparatus is designed to require only a single developer/wipe roll to perform the dual function of image development surface wiping. The single developer/wipe roll is supported for rotational movement in a direction opposite to the direction of movement of the recording medium and is in forward and leeward tangential engagement with a portion of the moving medium surface, respectively, to form a development apex and fluid seal between it and the recording medium surface and to wipe the recording medium surface to promote surface drying.

Liquid developing apparatus

A color electrographic recording apparatus is provided to produce on a recording medium a composite color image comprising a plurality of superimposed component images of different colors, e.g., magenta, cyan, yellow and black. The apparatus includes means for transporting the recording medium in opposite directions along a predetermined path through the electrographic recording apparatus, a recording station in the path and having a recording head with electrode means for forming a latent image on the recording medium, control means operative to energize the electrode means to create a latent image on the recording medium, a plurality of developing means adjacent either one side or both sides of the recording station in the path, each of the developing means for developing a latent image produced on the recording medium at the recording station into a corresponding visible component image of a respective color. The transport means is operative to pass a section of the recording medium through the recording station to form a first component latent image followed by its respective color development and reverse the direction of medium transport to permit formation of a next component latent image followed by its respective color development and repeating this process until all component latent images and their respective color development have been completed to form a composite color image. The color electrographic recording apparatus also includes unique registration means associated with the transport of the recording medium and the apparatus control means to form each component latent image so that all the component color images will be superimposed on one another even in spite of any shrinkage or expansion of the medium during its multiple handling and processing by the electrographic recording apparatus.

Color electrographic recording apparatus

A roll apparatus for supporting a continuous web of material is designed to maintain the web in proper alignment as the web is paid from or rewound onto the roll. The apparatus comprises a pair of frame members to rotatably support the roll on a pair of open ended bearing supports. A roll drive has a drive shaft extending to one end of the roll. An interengageable coupler is provided on both the output end of the roll drive shaft and the one end of the roll to permit the roll to be rotatably driven by the roll drive shaft while not being directly secured thereto. This allows for immediate lateral disengagement of the coupler means upon removal of the other end of the roll from its open ended bearing support. A spring loaded plunger is axially mounted at the one end of the roll and biased to move axially outward away from the roll for engagement against the output end of the drive shaft. A lateral translation drive is mounted on the other of the frame members with a lateral translation output mechanism engaging in axially aligned, abutting contact relation with the other end of the roll. This arrangement permits disengagement of the other end of the roll from the lateral translation output mechanism by lifting the other roll end out of its open ended bearing support together with lateral disengagement of the one roll end from the interengageable coupler.

Laterally translatable roll apparatus

A web tracking system for a continuous web of material which is transported from a supply to a takeup means along a predetermined path via one or more processing stations and comprises aligned tracking indica along at least one edge of the web. Means are provided to observe the tracking indica as the web is transported along the system path and produce information either indicative of dimensional changes in the length and width of the web due to web shrinkage or expansion or indicative of a particular point along the length of the web useful at one or more of the processing stations in the system.

Web tracking system

A capacitive charging mechanism is used in electrostatic stylus recorders having opposed writing nibs and counter electrodes to create electrostatic latent images on electrographic film and other dielectrically coated recording media. To capacitively charge the dielectric surface coating of such a recording medium, a writing voltage is first applied to one or more of the stylii or nibs and another writing voltage pulse is later applied to a counter electrode or electrode segment after a predetermined delay period which is selected to allow the nib voltages to stabilize. The charging of the dielectric surface coating of the recording medium to substantially a predetermined image voltage level occurs on the lead edge of the counter electrode writing voltage pulse. To prevent premature discharge of the charge deposited on the dielectric surface coating, the electrode writing voltage pulse is terminated before or simultaneously with the nib writing voltage pulse. Capacitive charging enables such recorders to print on electrographic film and other recording media having insulative substrates, accomodates increased printing rates, and reduces the sensitivity of the printing process to variations in the resistivity of the substrate when applied to recording on electrographic paper.

Capacitive electrostatic stylus writing with counter electrodes

A backup electrode arrangement comprises a resilient insulating member across one surface of which are a plurality of electrode segments separated from one another and comprising an electrically resistive material forming a shoe. The electrode shoes provide pressure engagement against an array of recording electrodes in an electrostatic recorder with a recording medium disposed therebetween. The electrical resistivity of the shoes is sufficiently high to protect the recording electrodes from pinhole shorts in the dielectric layer of the recording medium. With the backup electrode positioned directly opposite to the recording electrode array, the charging path impedance is reduced permitting reduction in writing speed and a corresponding increase in overall recording time.

Backup electrode for an electrostatic recorder

A system and method for monitoring and maintaining a predetermined concentration of material in a fluid body or carrier includes a control arrangement for detecting the transmissivity of a flow cell in each of two states. One of the states during which the flow cell is observed contains substantially no fluid present therein but provides a basis for determining the degree of existence of external factors affecting measurements made via the flow cell. The measurements for one state are subtracted from the measurements for the other in order to determine the transmissivity of the fluid body itself as distinguished from the combination of fluid body and flow cell.

System and method for monitoring and maintaining a predetermined

Recording machine such as electrostatic printer/plotter or facsimile plotter includes housing construction and associated operating components whereby overall external width reduction is accomplished without loss of function using liftable lid and method of cross-bracing. Machine serviceable through removable bottom closure panel supporting an electronic chassis. Operating stations, such as recording assembly including both electrostatic latent image recording station and a toner developing station, and web-cutting assembly each includes portions in both lid and base of housing to be yieldingly held together in cooperating relation by hinged latching panel in which the hinge pin supplies spring action to urge and retain the latching panel in its detented position.

Printer/plotter style system for confined installation and method

An improved toner fountain and recovery system for an electrostatic printing machine includes a fountain and supply arrangement for applying fluid toner material to a surface of a web of print material passing across the fountain and a vacuum-operated recovery head disposed to extend transversely of the path of movement of the web and in a manner whereby the recovery head removes toner from the surface of the web. A column of toner fluid forms a fluid head in fluid communication with a flow passage coupled to the recovery head in a manner permitting the height of the hydraulic head to establish the degree of vacuum applied to the recovery head. A valve operable between open and closed positions retains the head of toner responsive to arrested movement of the web so as to close the valve and retain the head of toner while the web is at rest.

Growing community of inventors

Los Altos, CA, United States of America

William A Lloyd