Abstract: A liquid developer system for use in electrostatic imaging processes of the positive toner type comprises toner particles micro-dispersed in a carrier liquid and at least one charge director compound soluble in the carrier liquid, wherein the total amount of charge director compound is associated with the toner particles and essentially no charge director compound is present in the carrier liquid. Especially useful charge director compounds are those which have been reacted with at least about one molar equivalent of at least one acid containing at least one organic moiety, the acid being effective in that the reacted positive charge director compound increases the short-term charging of the micro-dispersed toner particles as compared with charging when the same molar amount of unreacted charge director compound is used. Positive charge director compounds reacted with acid are e.g. those of the general formula RSiX.sub.

Abstract: A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperture and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cooling. When cool, the diluted composition will have a concentation of toner particles formed with a plurality of fibers.

Abstract: Imaging apparatus including an image forming surface, image forming apparatus for defining an electrostatic latent image on the image forming surface, the latent image having image portions and background portions, development apparatus for developing the electrostatic latent image in a reversal mode, using electrically charged pigmented toner particles to form a developed image overlying the image portions, whereby the developed image on the image forming surface is at a first electrical potential and the background portions on the image forming surface are at a second electrical potential, discharge apparatus for partially discharging the image forming surface so that the developed image is at a third electrical potential and the background portions are at a fourth potential and an image receiving surface at a fifth potential, for receiving the developed image from the image forming surface, wherein the difference between the fourth potential and the fifth potential is low enough such that substantially no

Abstract: Apparatus for fusing a thermoplastic image onto a substrate including a fuser element having a thin fusing member and apparatus for tensioning the thin fusing member.

Abstract: A liquid developer system contains electrically charged toner particles that are applied to a surface having a latent electrostatic image thereon for developing the image. The liquid developer system includes an insulating non-polar carrier liquid, toner particles dispersed in the carrier liquid, and at least one charge director compound that is only partially soluble in the carrier liquid. The charge director compound is supplied in solid form to the carrier liquid in excess of the amount that achieves saturation concentration. As a result, the compound is in equilibrium contact with the carrier liquid and maintains a predetermined concentration of dissolved charge director in the liquid developer system.

Abstract: Liquid toner imaging apparatus including an image bearing surface, apparatus for developing an image on the image bearing surface using a liquid toner including carrier liquid and pigmented particles, and apparatus for transferring a developed image from the image bearing surface to a substrate. The apparatus for developing includes a developer electrode having a developer surface portions of which sequentially come into propinquity with the image bearing surface and subsequently leave propinquity therewith, each region forming a development region during its propinquity and a stationary nozzle for providing liquid toner of a given color to the development region by supplying liquid toner onto a portion of the developer electrode, wherein the nozzle is spaced more than 8.4 mm from any other nozzle which supplies liquid toner of the given color to the development region.

Abstract: A variable magnification electrophotographic copier wherein the ratio of object and image distances is changed by rotating a focusing device about an axis orthogonal to its optical axis. In a preferred embodiment, the focusing device is a refractive lens having a shape factor different from zero; the rotational axis intersects the optical axis; and the rotation angle is 180.degree. selectively to reverse the lens surfaces and provide images of two different magnifications each having minimum spherical aberration.

Abstract: A method for maintaining a preselected concentrations of first and second charge directors in a toner composition, where such composition is being subjected to a use in which initial concentrations of the first and second charge directors are being depleted.

Abstract: Imaging apparatus including an electrostatic imaging surface, latent image forming apparatus for forming an electrostatic latent image on said electrostatic imaging surface and development apparatus for developing said electrostatic latent image which includes supply apparatus for supplying a liquid toner to the image forming surface, the supply apparatus including a multiplicity of independently controllable outlets, preferably spray outlets, and a development surface for developing the electrostatic latent image using the liquid toner. The supply apparatus is preferably a multi-color supply apparatus and the multiplicity of outlets includes a plurality of individually controllable outlets, for supplying liquid toner of each of a plurality of colors.

Abstract: A process for preparing a liquid toner compsition which includes the steps of combining first and second types of pigmented particles and mixing them together whereby the first type of pigmented particles acquire charges of a first polarity and the second type of pigmented particles acquire charges of a second polarity opposite to the first polarity.

Abstract: A ribbon ink has a viscosity that increases with increasing rate of shear for rates of shear greater then a predetermined value. A printer ribbon for use with an impact printer comprises a substrate containing ink having a viscosity that increases with increasing rate of shear for rates of shear greater then a predetermined value.

Abstract: An imaging system including an image bearing surface and an intermediate transfer member having an image transfer surface and being operative for transfer of toner images from the image bearing surface to the image transfer surface and for subsequent transfer to a substrate. The intermediate transfer member includes a backing layer, a compressible layer disposed between the image transfer surface and the backing layer and a heating layer which is disposed between the backing layer and the compressible layer.

Abstract: Liquid toner imaging apparatus for producing an image on a substrate and having carrier liquid and toner particle carryout on the average in a first ratio, the apparatus including an image bearing surface, apparatus for developing an image on the image bearing surface using a liquid toner inlcuding carrier liquid and toner particles and apparatus for transferring a developed image from the image bearing surface to the substrate. The apparatus for developing includes a liquid toner reservoir, supply apparatus including a replaceable enclosure initially containing toner concentrate including carrier liquid and toner particles therein and having an opening communicating with the reservoir and replenishment apparatus for causing transfer of toner concentrate from the replaceable enclosure to the reservoir to replenish the toner for causing transfer of contents of the reservoir to the replaceable enclosure to remove excess liquid toner from the reservoir.

Abstract: Dispersion apparatus for dispersing a first material in a second material comprising an enclosure having disposed therein an apertured divider defining first and second sub-enclosures within said enclosure on opposite sides of said divider, a first inlet for said first material communicating with said first sub-enclosure, a port for said second material communicating with said second sub-enclosure, and means for enhancing the passage of materials through said divider.

Abstract: Apparatus for dispersion of solids in liquids including two relatively movable elements arranged so as to define a dispersing volume therebetween, a multiplicity of separate generally cylindrical dispersing elements disposed within the dispersing volume, and apparatus for supplying a solid suspended in a liquid to the dispersing volume for dispersing and for removing a solid dispersed in a liquid from the dispersed volume after dispersing, wherein the relatively movable elements are separated at the dispersing volume by a separation distance which is slightly greater than the minimum dimension of the dispersing elements.

Abstract: A humidity tolerant charge director composition comprises a fine dispersion in a non-polar solvent of a charge direction material comprising a molecular charge director compound and an ionic charge director compound, each being conjugated to a polymer which is insoluble in non-polar organic solvents. The charge director material is prepared by adding to a solution of a molecular charge director compound and an ionic charge director compound in a non-polar organic solvent, a monomer compound capable of polymerizing to form a polymer which is insoluble in said solvent, initiating a polyerization reaction of the monomer compound and allowing the polmerization reaction to progress to completion.

Abstract: An image system including an image bearing surface and an intermediate transfer member operative for transfer of liquid toner images from the image bearing surface to a substrate provides for first transfer engagement between the intermediate transfer member and the image bearing surface for transfer of an image from the image bearing surface to the intermediate transfer member at a first pressure, producing deformation of the intermediate transfer member to a first deformation degree. The system provides for second transfer engagement between the intermediate transfer member and the substrate for transfer of the image from the intermediate transfer member to the substrate at a second pressure, producing deformation of the intermediate transfer member to a second deformation degree.

Abstract: Dual color imaging process and system providing formation of an image having adjacent first and second areas respectively containing first and second types of pigmented particles undesirably separated by third areas relatively free of particles of the first and second types and causing the image to flow into the third areas, thereby at least partially eliminating the third areas.

Abstract: Apparatus for image transfer including an image bearing surface arranged to support a liquid toner image thereon, including image regions and background regions, means for removing pigmented toner particles from the vicinity of background regions defined on the image bearing surface, means for rigidizing the toner image at the image regions, and an intermediate transfer member for receiving the toner image from the image bearing surface after rigidization thereof, for transfer of the image to a substrate.