Abstract: In a development system there is provided a developer transport adapted for depositing developer material on an imaging surface having an electrostatic latent image thereon, including: a housing defining a chamber storing a supply of developer material including carrier and toner; a donor member, mounted partially in the chamber and spaced from the imaging surface, for transporting developer on an outer surface thereof to a region opposed from the imaging surface, the donor member having a magnetic assembly having a plurality of poles, a sleeve, enclosing the magnetic assembly, rotating about the magnetic assembly; a plurality of trim bars positioned about the donor roll at a predefined positions and spacing around the donor roll, the a plurality of trim bars progressively reducing developer bed height of the developer material on the donor member to a predefine developer bed height within the development nip.

Abstract: An electrographic, two-component dry developer composition comprising charged toner particles and oppositely charged carrier particles which (a) includes: a soft magnetic material exhibiting a coercivity of less than 300 gauss when magnetically saturated and (b) exhibit an induced magnetic moment of less than 20 EMU/gm of carrier when in an applied field of 1000 gauss; and a hard magnetic material exhibiting a coercivity of at least 300 gauss when magnetically saturated and (b) exhibit an induced magnetic moment of at least 20 EMU/gm of carrier when in an applied field of 1000 gauss.

Abstract: An electrographic, two-component dry developer composition including charged toner particles and oppositely charged carrier particles which (a) includes: an combination of a soft magnetic material exhibiting a coercivity of at least 300 gauss when magnetically saturated, exhibit an induced magnetic moment of less than 20 EMU/gm of carrier when in an applied field of 1000 gauss and (b) a hard magnetic material exhibiting a coercivity of at least 300 gauss when magnetically saturated, exhibit an induced magnetic moment of at least 20 EMU/gm of carrier when in an applied field of 1000 gauss.

Abstract: A resonator for applying vibrational energy to a member, for example a photoreceptor belt or developer/donor member, includes an energy transmitting horn member having a platform portion and a horn portion, the horn portion including a contacting portion for contacting a surface of the member, and a piezoelectric material in association with the horn member for driving the horn member to vibrate, the piezoelectric material responsive to a voltage signal from a voltage source. The piezoelectric material is a composite of at least one piezoceramic material and at least one of a polymer or air, and has a 1-3 configuration. By the selection of a piezoceramic/polymer composite material having the specified configuration for use as the vibratory energy producing source, or transducer, of a resonator, improved piezoelectric material performance is achieved, particularly with respect to control and/or elimination of undesired transverse vibration, and manufacturing complexity is reduced.

Abstract: Apparatus for non-interactive, dry powder development of electrostatic images on an imageable surface with developer material; including a housing containing developer material; a resonating donor member, spaced from the imageable surface, for transporting developer material to a development zone adjacent the imageable surface, the resonating donor member forming a cloud of developer material in the development zone to develop the images.

Abstract: An apparatus for non-interactive, dry powder development of electrostatic Images composed of solid areas and fine lines areas on an imageable surface including a housing containing developer material; a magnetic member, spaced a predefined distance from the image, for transporting the developer material from the housing to develop solid areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core; and a donor member, adjacent to the magnetic roll and spaced from the image receiving member and adapted to transport marking particles to a development zone adjacent the image receiving member; an electrode positioned in the development zone between the image receiving member and the donor member; a voltage supply for electrically biasing the electrode during a developing operation with an alternating current to detach marking particles from said donor member, forming a cloud of marking particles in the development zone, and developing fine

Abstract: An apparatus for non-interactive, dry powder development of electrostatic Images composed of solid areas and fine lines areas on an imageable surface including a housing containing developer material; a magnetic member, spaced a predefined distance from said image, for transporting said developer material from said housing to develop solid areas of said image, said magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about said magnetic core; and a resonating donor member, adjacent to said magnetic roll and spaced from the image receiving member and adapted to transport marking particles to a development zone adjacent the image receiving member; an electrode positioned in the development zone between the image receiving member and the donor member; a voltage supply for electrically biasing said electrode during a developing operation with an alternating current to detach marking particles from said resonating donor member, forming a cloud of marking particles in the develop

Abstract: An apparatus for non-interactive, dry powder development of electrostatic Images composed of solid areas and fine lines areas on an imageable surface including a housing containing developer material; a first magnetic roll, spaced a first predefined distance from the image, for transporting the developer material from the housing to develop solid areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core; and a second magnetic roll, spaced a second predefined distance from the image, for transporting the developer material from the housing to develop fine line areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core.

Abstract: A method that enhances safety while producing toners that are .ltoreq.5.mu. to be used in developing an electrostatic image includes providing selectable color toner liquids on demand to a mixing station; mixing the provided color toner liquids at the mixing station; producing a mist from the mixed toner liquid; collecting color toner particles resulting from the mist cooling; depositing the color toner particles in a development sump that includes carrier beads; and mixing the color toner particles with the carrier beads to produce two-component developer.

Abstract: Apparatus for removing residual charged toner particles from a charge retentive surface characterized by a self-biasing pyroelectric cleaner brush and a detoning member for removing the charged particles from the self-biasing pyroelectric cleaner brush. The brush includes a pyroelectric polymer supported by a conductive roll with resistive fibers attached to one surface of the pyroelectric polymer. Heating and cooling of a pyroelectric polymer induces thermal expansion or contraction which create surface charge density charges that are used to supply charge to the resistive fibers. The oppositely charged resistive fibers contact the toner particles on the charge retentive surface to thereby remove them from the charge retentive surface.

Abstract: A method for supplying custom color in an image development system includes providing selectable color toner liquids on demand to a mixing station; mixing the provided color toner liquids at the mixing station; providing a mist from the mixed toner liquid; transporting the mist to a developer station; passing the mist between a development electrode and a recording member onto which a latent electrostatic image is positioned; providing an electric field between the development electrode and the recording member; and attracting the mist by means of the electric field to the electrostatic image to thereby develop the electrostatic image.

Abstract: An apparatus in which the developability and interactivity of electrostatically charged particles in a mixture of particulate material is measured. The sensor apparatus includes a transparent member positioned closely adjacent to a developer roller of an electrophotographic printing machine. Electrostatically charged particles are attracted from the particulate mixture being transported by the developer roller to the member. A beam of energy is transmitted through the member. The intensity of the internally reflected beam is detected and a signal generated indicative of the quantity of charged particles adhering to the member. A cleaning field bias is applied, to determine if a signal indicative of the charge particles being removed (interactivity) from the member is generated.

Abstract: A development system including a developer transport adapted for depositing developer material on an imaging surface having an electrostatic latent image thereon, including a housing defining a chamber storing a supply of developer material including toner. A donor member is mounted partially in said chamber and spaced from the imaging surface, for transporting developer on an outer surface thereof to a region opposed from the imaging surface. The donor member has a magnetic assembly, which includes a plurality of poles, and a sleeve, enclosing said magnetic assembly and rotating about said magnetic assembly. A sensor measures a magnetic field of said donor roll at a predefined position on said donor roll. A magnetic system generates a magnetic field to reduce developer bed height of said developer material on said donor member in a development zone.

Abstract: Ferroelectric polymer films are applied in a charge transfer imaging process to generate latent electrostatic images on a dielectric receiver media. The dielectric receiver media may be the final imaging substrate which is then xerographically toned and fixed, e.g., Versatec dielectric paper, or an intermediate surface from which a toned image is transferred to plain paper. Charges may be generated applying either the piezoelectric or the pyroelectric effect exhibited by ferroelectric films.

Abstract: A development system including a developer transport adapted for depositing developer material on an imaging surface having an electrostatic latent image thereon, including a housing defining a chamber storing a supply of developer material including toner. A donor member is mounted partially in said chamber and spaced from the imaging surface, for transporting developer on an outer surface thereof to a region opposed from the imaging surface. The donor member has a magnetic assembly, which includes a plurality of poles, and a sleeve, enclosing said magnetic assembly and rotating about said magnetic assembly. A magnetic system generates a magnetic field to reduce developer bed height of said developer material on said donor member in a development zone.

Abstract: An acoustic scavengeless assist (ASA) development apparatus, and a multicolor image reproduction machine including such a development apparatus. The (ASA) development apparatus includes a biased vibratory section having a piezoelectric member and a donor member, as well as, a development electrode section, for presenting toner particles to latent electrostatic images for image development. The donor member is positioned within the reproduction machine and forms a development nip with a latent image bearing surface of a photoreceptor of the reproduction machine. Importantly, the biased vibratory section has at least a first conductive electrode formed therein adjacent to the piezoelectric member for effecting controlled vibratory toner release from the donor member, and a first bias for biasing the at least first conductive electrode.

Abstract: Developed image noise is reduced by momentarily breaking the close range forces holding toner non-uniformly to a charge retentive surface in an electrostatic image. The source of the image noise can be of a mechanical nature, such as, raking by carrier beads in conventional two component development. The short range forces are broken by applying ultrasonic vibration to the charge retentive surface.

Abstract: A cylindrical and rotatable resonating assembly, generally for use in electrostatographic applications. The resonating assembly is preferably positioned along a longitudinal axis generally transverse to the process direction of movement of a toner bearing member, for applying uniform vibratory energy thereto. The cylindrical form of the resonating assembly allows for rotation of the assembly while remaining in contact with the image bearing member to reduce frictional forces between a contact surface of the resonating assembly and the image bearing member which, in turn, reduces wear of the resonating assembly as well as the image bearing member.

Abstract: A contact charging system uniformly charges a photoconductive surface by the use of a resistive belt surrounding and moved by two rollers and in contact with the photoconductive surface. The roller at the pre-nip area is grounded while that at the post-nip area is kept at a desired high potential. Alternatively, a pair of shoes are used for contact charging a photoconductive surface with one of the shoes being grounded and the other being biased to a desired DC potential by a biasing source. A resistive film is in contact with the pair of shoes with both the film and shoes being in contact with the photoconductive surface. Also, a blade is used to uniformly charge a photoconductive surface with one portion of the blade being grounded and another portion being biased to a desired DC potential. The blade is in direct contact with the photoconductive surface. This charging system tailors the electric field so that air breakdown only occurs at the post-nip area.

Abstract: Pyroelectric materials are used to create net charge/surface potentials for use in xerographic charge and transfer steps. Heating and cooling a pyroelectric film, such as, polyvinylidene fluoride induces thermal expansion or contraction which create surface charge density changes that can be used to charge a photoconductive surface and/or transfer an image from a photoconductive surface to a copy sheet.