摘要:
A specified and designated, non-primary color print (imaging) is applied to a substrate (paper) by mixing at least first and second differently colored toner particles having substantially uniform physical characteristics, and introducing them in desired proportions into a fluidized bed. The toner powders are uniformly mixed together in the fluidized bed (as by using rotors in addition to applying fluidizing air to the bed), and then a substantially uniform electrostatic charge (e.g. about +6.5-+8 kV D.C., which can be applied by blades on the rotor) is applied to the bed, and then the electrostatically charged mixture of toner particles is applied to the substrate, to image uniform non-primary color symbols on the substrate. The uniform physical characteristics of the powders are size (the vast majority of particles having a size between about 5 microns and about 25 microns), a resistivity of greater than 10.sup.12 ohm-cm, and a flowability between a predefined minimum and maximum. When utilizing the fluidized bed as according to the invention, slight changes in chemical composition of the toners may be easily accommodated without change in the resulting uniform imaging.
摘要:
The ion deposition web-fed engine includes a first fixed frame, a second frame pivotally mounted to the first frame, a third frame carried by the second frame for pivotal movement therewith and for movement in a transverse direction relative to the first and second frames. The third frame carries a print unit including an image cylinder for cooperation with an impression cylinder carried by the first frame. For servicing purposes, the second frame is pivoted relative to the first frame to provide access to the paper web, impression cylinder and image cylinder. Upon closing the second frame onto the first frame, the image cylinder defines an open nip with the impression cylinder. The print unit is movable linearly toward the impression cylinder to close the nip into a print condition.
摘要:
An erase unit for an ion deposition web-fed print engine includes a plenum extending the width of the electrostatic image on the image cylinder and defining an ionization chamber with the image cylinder surface. The plenum has first and second electrodes separated by a dielectric. Upon application of a time-varying potential having a frequency of 0.2 to 50 mHz across the electrodes, ionization occurs, causing an ion current flowing in relation to the image surface until the image surface and the biasing electrode are at the same potential, thus erasing any residual electrostatic image on the cylindrical surface. By providing a DC biasing voltage, the residual electrostatic image may be erased when equalization occurs, with the image cylinder maintaining a pre-charged potential.
摘要:
A method and apparatus are provided for "field effect imaging" of moving substrates, such as webs of paper. Non-conductive, non-magnetic toner having approximately a 5-20 micron mean particle size is electrically charged to a level of at least about 8 micro Coulombs/gram and then a first roller with a conductive surface is brought into operative association with the electrically charged toner so that toner particles adhere to the surface. The toner particles are preferably maintained in an electrostatic fluidized bed, and charged by a corona element in the bed. An array of pin or stylus primary electrodes are selectively energized or de-energized to provide no-write or write condition, respectively using a computer to switch the electrodes into or out of operative connection to a source of electrical potential. The toner particles are transferred from the first roller to a substrate either directly (after passing past the primary electrodes), or they are first transferred to a second roller which then brings the toner particles into contact with the substrate. If a second roller is utilized, the primary electrodes can be in association with the first roller, or between the first and second rollers for transferring only "write" toner to the second roller.
摘要:
Electrically conductive magnetic toner is supplied to an electrostatic printing apparatus by dispensing it pneumatically from one of two different toner bottles mounted on dispenser blocks. The toner passes through a chute into a container having an air previous, toner impervious, bottom. The toner particles are fluidized in the container, and come into contact with the rotating surface of an applicator roller having interior magnets, and the amount of toner which stays on the applicator roller surface is controlled in part by rotating the surface past a metering blade. To periodically declump the toner, a mechanical element is depressed which reverses the direction of the applicator roller, and brings a scraper blade into contact with the surface of the applicator roller, and applies a high level of vacuum to remove scraped off toner.
摘要:
A security document is produced from a paper substrate having invisible hydrophobic toner blended into the paper. The clear toner is produced by milling and classifying a polyester resin, mixing it with silica flowing agent, and then electrostatically imaging the toner onto the paper substrate, as a spot that can be overprinted, or preferably as indicia that is not visible to the naked eye or color copiers. An infra-red absorbing or UV responsive dye may be added to the toner so that it is visible under infra-red/ultraviolet light respectively, or without that dye it is not visible when eliminated by light of any wavelength. When applied to the paper the toner is snow white, but after infra-red heat fusing it blends into the paper and is substantially invisible. The security indicia is easily made visible by passing a conventional marker nib over it, or other mechanism for applying a water based low concentrate colored ink which is readily absorbed by the surrounding paper, but not by the hydrophobic security indicia.
摘要:
In electrostatic imaging utilizing a silent electric discharge, nitrogen or other controlled gas is supplied to the discharge region. First and second control fingers each having first and second ends and a number of active openings along their lengths, provide electrodes at the discharge region. The controlled gas is supplied to the discharge regions through first and second gas input channels each connected to either the first ends or second ends of both the control fingers. The charge output associated with the active openings in the control fingers is stabilized so that there is a substantially even distribution of charge output along the length of each control finger by providing first and second bleed holes associated with each of the control fingers, and closer to the gas input channel than are the active openings in the control fingers. Each bleed hole has a surface area of approximately three times that of a single active opening if each control finger has sixteen active openings, and the bleed holes are preferably formed in a screen electrode overlying the control fingers.
摘要:
A substrate capable of receiving and retaining imaging is coded so as to maximize the amount of the scannable information that can be packed into an area, and/or to provide an effective security feature. A first machine readable identification code (e.g. bar code) is imaged on a predetermined area of the substrate, and is opaque to a first predetermined wavelength range of electromagnetic energy (e.g. the infra-red region of light). An overlay is applied over and at least partially covering the first code. The overlay is transparent to the first wavelength range, and opaque to a second wavelength range (e.g. the visible spectrum of light). The overlay may be a security block which substantially completely covers the first code, or may be a second bar code (or additional codes) which is transparent to the second range. The codes may be read by multiple passes of different scanner heads by relative movement between the heads and the substrate, or by a scanner in which first and second (or more) different scanner heads are mounted together so that two different wavelength range bar codes on the substrate may be read at the same time.
摘要:
A method and apparatus are provided for "field effect imaging" of moving substrates, such as webs of paper. Non-conductive, non-magnetic toner having approximately a 5-20 micron mean particle size is electrically charged to a level of at least about 8 micro Coulombs/gram and then a first roller with a conductive surface is brought into operative association with the electrically charged toner so that toner particles adhere to the surface. The toner particles are preferably maintained in an electrostatic fluidized bed, and charged by a corona element in the bed. An array of pin or stylus primary electrodes are selectively energized or de-energized to provide no-write or write condition, respectively using a computer to switch the electrodes into or out of operative connection to a source of electrical potential. The toner particles are transferred from the first roller to a substrate either directly (after passing past the primary electrodes), or they are first transferred to a second roller which then brings the toner particles into contact with the substrate. If a second roller is utilized, the primary electrodes can be in association with the first roller, or between the first and second rollers for transferring only "write" toner to the second roller.
摘要:
A method and apparatus are provided for "field effect imaging" of moving substrates, such as webs of paper. Non-conductive, nonmagnetic toner having approximately a 5-20 micron mean particle size is electrically charged to a level of at least about 8 micro Coulombs/gram and then a first roller with a conductive surface is brought into operative association with the electrically charged toner so that toner particles adhere to the surface. The toner particles are preferably maintained in an electrostatic fluidized bed, and charged by a corona element in the bed. An array of pin or stylus primary electrodes are selectively energized or de-energized to provide no-write or write condition, respectively using a computer to switch the electrodes into or out of operative connection to a source of electrical potential. The toner particles are transferred from the first roller to a substrate either directly (after passing past the primary electrodes), or they are first transferred to a second roller which then brings the toner particles into contact with the substrate. If a second roller is utilized, the primary electrodes can be in association with the first roller, or between the first and second rollers for transferring only "write" toner to the second roller.