Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of a member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a variable voltage waveform onto which a DC bias is superimposed. The amount of DC bias is selected to set the signal voltage such that a minimally acceptable amount of AC corona is created sufficient for uniform photoreceptor charging while avoiding unnecessary excessive positive corona that causes excessive photoreceptor wear.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a rectified AC waveform onto which a DC bias is superimposed after the waveform has been rectified. The result is the ability to raise the voltage potential of the photoreceptor with less pulse voltage and, more particularly, to increase the voltage potential of the photoreceptor along as if only DC voltage were applied far above what is possible in the prior art. Among the advantages of the invention is the ability to minimize photoreceptor wear at higher levels of photoreceptor charge since the DC-offset bias enables the second Paschen threshold to be avoided for higher levels of the photoreceptor charge.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a rectified AC waveform onto which a DC bias is superimposed after the waveform has been rectified. The result is the ability to raise the voltage potential of the photoreceptor with less pulse voltage and, more particularly, to increase the voltage potential of the photoreceptor along as if only DC voltage were applied far above what is possible in the prior art. Among the advantages of the invention is the ability to minimize photoreceptor wear at higher levels of photoreceptor charge since the DC-offset bias enables the second Paschen threshold to be avoided for higher levels of the photoreceptor charge.

Abstract: An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of a member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a variable voltage waveform onto which a DC bias is superimposed. The amount of DC bias is selected to set the signal voltage such that a minimally acceptable amount of AC corona is created sufficient for uniform photoreceptor charging while avoiding unnecessary excessive positive corona that causes excessive photoreceptor wear.

Abstract: Apparatus for charging a substrate, comprising: an elongated charging member having a crowned surface; an elongated pressure member having, the pressure member being supported for pressure engagement with the charging member to form a nip therebetween adapted to receive the substrate. There is also disclose a method for making the apparatus.

Abstract: Apparatus for charging a substrate, comprising: an elongated charging member having a crowned surface; an elongated pressure member having, the pressure member being supported for pressure engagement with the charging member to form a nip therebetween adapted to receive the substrate. There is also disclose a method for making the apparatus.

Abstract: A charge transport layer material for a photoreceptor includes at least a polycarbonate polymer binder having a number average molecular weight of not less than 35,000, at least one charge transport material, polytetrafluoroethylene particle aggregates having an average size of less than about 1.5 microns and a fluorine-containing polymeric surfactant dispersed in a solvent mixture of at least tetrahydrofuran and toluene. The dispersion is able to form a uniform and stable material ideal for use in forming a charge transport layer of a photoreceptor. The resultant charge transport layer exhibits excellent wear resistance against contact with an AC bias charging roll, excellent electrical performance, and delivers superior print quality.

Abstract: A charge transport layer material for a photoreceptor includes at least a polycarbonate polymer, at least one charge transport material, polytetrafluoroethylene particle aggregates having an average size of less than about 1.5 microns, hydrophobic silica and a fluorine-containing polymeric surfactant dispersed in a solvent. The presence of the hydrophobic silica enables the dispersion to have superior stability by preventing settling of the PTFE particles. A resulting charge transport layer produced from the dispersion exhibits excellent wear resistance against contact with an AC bias charging roll, excellent electrical performance, and delivers superior print quality.

Abstract: A rotatable charging apparatus includes a length extending between a first end and a second end, with the rotatable charging apparatus centered about an axis parallel to the length. The rotatable charging apparatus outer periphery forms N apparatus positions. One charging device is fixed to each of N−1 apparatus positions. The remaining (Nth) apparatus position is devoid of a charging device, thus forming an “empty” charging device position. A host printing machine selectively causes the rotatable charging apparatus to rotate about its axis thereby selectively position any of its N−1 charging devices to face a proximately-located photosensitive element. When a problem exists with the current charging device, or when the total number of operating hours of the current charging device exceeds a fixed threshold, the printing machine causes the rotatable charging apparatus to rotate from its current charging device to position a new charging device facing the photosensitive element.

Abstract: Disclosed is a fluid deposition apparatus comprising (a) a fluid supply, (b) a porous fluid distribution member in operative connection with the fluid supply, enabling wetting of the fluid distribution member with a fluid, and (c) a porous metering membrane situated on the fluid distribution member, whereby the metering membrane enables uniform metering of the fluid from the fluid distribution member onto a substrate.

Abstract: An apparatus and method that insures an even distribution of liquid in an aquatron charging device across the entire length of the device. This enables uniform charging across the width of the photoreceptor. The present invention fills and pressurizes a porous tube with a liquid. The liquid evenly exudes from the pores along the entire length of the porous tube. A hydrophilic liquid retentive foam which contacts the photoreceptor surface is wrapped snugly around the tube. The conductivity and overall rate of dispensation of liquid is controlled by the pressure differential across the porous tube.

Abstract: An electrostatographic printing machine and apparatus that utilizes a two layer roll charger for contact charging of photoreceptors. The charger includes a liquid retentive foam layer fitted over an electrically conductive shaft. The shaft can be solid or porous, the later requiring a separate liquid reservoir. The second layer is a thin liquid permeable member, over the foam layer, which transmits water at a slow, but controlled rate during the rotation of the roller. The roller may rotate synchronously with the photoreceptor or be allowed to slip on the photoreceptor surface to improve uniformity and contact. The membrane increases life by controlling the runout of liquid from the repository. Also, the present invention permits charging over photoreceptor pinholes.

Abstract: An electrostatographic printing machine and apparatus that utilizes a foam roll aquatron with a hydrophilic web between it and the photoreceptor. The porous web captures and removes toner particles which ordinarily would be trapped in the foam roll nip and cause image quality defects, such as streaking.

Abstract: An apparatus, printing machine and method for replenishing an aquatron liquid reservoir in an aquatron charging device. The print media (e.g. paper, vellum, etc.) releases liquid from the print media during fusing. A condenser creates condensate from the liquid released by the print media which is collected in a conduit and transported using air flow into a collection container. This collection container can be the aquatron liquid reservoir, or a separate collection container that pumps liquid to the aquatron liquid reservoir, thus, enabling replenishing the liquid supply of the aquatron liquid reservoir within the printing machine. Sensing devices measuring liquid concentration resistance in the aquatron liquid reservoir and/or the collection container control the liquid level of the reservoir and/or collection container.

Abstract: An apparatus and method that utilize a sensor circuit and a liquid supply to control resistance of a fluid carrier of an aquatron. The resistance of the fluid carrier or charging pad is maintained by controlling the loading or concentration of liquid in the charging pad. A comparison of the fluid or liquid level in the charging pad to the desired fluid level for the charging pad triggers the addition or reduction of fluid to the charging pad to achieve the desired fluid level and thus the desired resistance. A minimum fluid carrier resistance is required to prevent loading the power supply when charging over pinholes and scratches in the imaging surface.

Abstract: An apparatus for charging an ionographic member, comprising an electrically insulating substrate containing affixed thereto a plurality of electroded grooves each capable of retaining a single wettable fiber, thereby forming a collection of fibers in contact with the substrate; a resin layer that isolates said fibers from each other, and that adheres the fibers to the electroded grooves; providing an ionically conductive fluid to said collection of fibers; applying an electrical bias to said fibers thereby transporting ions through the fibers to the surface of said ionographic member and which ions charge said member.

Abstract: A power supply for transmitting voltage to a device, including a web having a piezoelectric exterior layer for generating a voltage on the surface thereof in response to being deformed. The web is entrained about a roller arrangement to deform the piezoelectric exterior layer. Commutation brushes transfers the voltage generated on the surface of the piezoelectric exterior layer to the device. The roller arrangement in combination with the placement of commutation brushes and neutralization brushes are used to adjust the voltage to the device.

Abstract: An apparatus for applying an electrical charge to a charge retentive surface by transporting ions through an ionically conductive liquid and transferring the ions to the member to be charged across the liquid/charge retentive surface interface. The ionically conductive liquid is contacted with the charge retentive surface for depositing ions onto the charge retentive surface via a wetted donor blade supported within a conductive housing, wherein the housing is coupled to an electrical power supply for applying an electrical potential to the ionically conductive liquid. In one specific embodiment, the charging apparatus includes a support blade for urging the donor blade into contact with the charge retentive surface and a wiping blade for wiping any liquid from the surface of the charge retentive surface as may have been transferred to the surface at the donor blade/charge retentive surface interface.

Abstract: A process for changing layered imaging members by the transfer of ions thereto which comprises contacting the imaging member with a liquid developer comprised of a nonpolar liquid, and a mixture of surfactants of an ammonium block copolymer first surfactant of the formula ##STR1## wherein X.sup.- is a conjugate base or anion of a strong acid; R is hydrogen or alkyl; R' is alkyl; R" is an alkyl group containing from about 6 to about 20 carbon atoms; and y and x represent the number average degree of polymerization (DP) wherein the ratio of y to x is in the range of from about 10 to 2 to about 1,000 to 200; and a second surfactant component of the formula ##STR2## wherein R.sub.1 is selected from the group consisting of hydrogen and alkyl, and n is 0 (zero), 1, 2, 3, or 4.

Abstract: A process for charging layered imaging members by the transfer of ions thereto from an ionically conductive medium.