Abstract: A method and apparatus are presented for electrostatic deposition of dry powder to a tablet, capsule, or a specific area of any of a wide range of pharmaceutical substrates. The apparatus includes: a magnetic brush having a rotatable multi-pole magnetic core and a stationary outer shell; a developer supply for supplying a magnetic developer powder, consisting of a magnetic carrier particles and pharmaceutical dry powder particles, to the magnetic brush; a print head on the outer shell; a tablet or other pharmaceutical substrate arranged in spaced relation to the print head to define a pharmaceutical powder transfer region through which the substrate can be moved.

Abstract: A method and apparatus are presented for electrostatic deposition of dry powder to a tablet, capsule, or a specific area of any of a wide range of pharmaceutical substrates. The apparatus includes: a magnetic brush having a rotatable multi-pole magnetic core and a stationary outer shell; a developer supply for supplying a magnetic developer powder, consisting of a magnetic carrier particles and pharmaceutical dry powder particles, to the magnetic brush; a print head on the outer shell; a tablet or other pharmaceutical substrate arranged in spaced relation to the print head to define a pharmaceutical powder transfer region through which the substrate can be moved.

Abstract: Electrographic printing apparatus for forming a toner image on a recording medium includes: a magnetic brush having a rotatable magnetic core and a stationary outer cylindrical shell; a developer supply for supplying a magnetic developer powder to the magnetic brush; an array of microchannels on the outer shell for forming a plurality of parallel lines of developer in the channels; means for selectively transferring developer from the lines to a receiver; and a receiver electrode arranged in spaced relation to the array of microchannels to define a recording region through which the receiver can be moved.

Abstract: An AC corona charging arrangement includes a corona generating device connected through a capacitive connection to an AC voltage source and partially surrounded by a conductive shield connected to DC voltage source. In one embodiment the corona generating device is a wire having a diameter of about 50 microns and in another embodiment the corona generating device is a row of pins connected through corresponding capacitance to the AC voltage source. The presence of a capacitance between the AC voltage source and the corona generating device provides a curve representing the relationship between the current between the charging device and an adjacent conductive plate and the shield voltage which is concave downwardly, resulting in a high charging rate and greater uniformity of charging of a photoreceptor surface.

Abstract: Electrographic printing apparatus for forming a toner image on a recording medium includes: a magnetic brush having a rotatable magnetic core and a stationary outer shell; a developer supply for supplying a magnetic developer powder to the magnetic brush; a print head on the outer shell; and a receiver electrode arranged in spaced relation to the print head to define a recording region through which the receiver can be moved.

Abstract: A magnetic brush development roller assembly for an electrographic printer includes a cylindrical multipole magnet mounted for rotation about a cylindrical axis; and a conductive non-magnetic stationary shell surrounding the multipole magnet. The shell defines an axial slot for receiving an imaging head, and has a region of reduced conductance extending substantially around the circumference of the shell, whereby eddy currents generated by rotation of the magnet within the shell and hence resistive heating and drag on the magnet are reduced.

Abstract: An electrographic printing apparatus for forming a toner image on a recording medium, includes: a) a magnetic brush having a rotatable magnetic core and a stationary outer cylindrical shell; b) an addressable array of transfer electrodes on the outer shell, the array including a plurality of parallel strips of high magnetic permeability, electrically conductive material arranged circumferentially around the shell and disposed under an electrically insulating layer, the insulating layer defining printing gaps over the strips; c) a receiver electrode arranged in spaced relation to the array of transfer electrodes to define a recording region through which a receiver can be moved; d) a developer supply for supplying developer powder having an electrically conductive, magnetic carrier and a first colored toner to the magnetic brush, and e) an electronic circuit adapted to selectively apply voltage pulses to the transfer electrodes to cause the toner to transfer from the developer powder to the receiver in an imag

Abstract: Electrographic printing apparatus for forming a toner image on a recording medium, includes: a magnetic brush having a rotatable magnetic core and a stationary outer shell; a developer supply for supplying a magnetic developer powder including toner to the magnetic brush. A print head on the outer shell forms a plurality of parallel lines of developer. Toner is selectively transferred from a plurality of electrodes within each line to a receiver. A receiver electrode is arranged in spaced relation to the print head to define a recording region through which the receiver can be moved.

Abstract: A process for manufacturing a field replaceable laser writer spindle assembly having a shaft with two ball bearings and a spindle head, comprises the steps of preloading both ball bearings to a predetermined level. The spindle head is rotated about a longitudinal axis of the spindle assembly, and a reference surface of the spindle head is ground to a predetermined tolerance for minimizing runout of the reference surface for producing the field replaceable spindle assembly.

Abstract: Electrographic printing apparatus includes a developer supply for supplying a developer having a toner component; a print head for transferring toner from the developer supply in an image wise manner; and a compliant receiver for receiving the image wise toner from the print head. The receiver has a compliant inner conductive blanket layer for allowing the receiver to conform to a print medium and a non-compliant overcoat layer for efficiently releasing toner from the receiver. The image wise toner is transferred from the compliant receiver to the print medium at a transfer station.

Abstract: Electrographic printing apparatus for forming a toner image on a recording medium, includes a magnetic brush having a rotatable magnetic core and a stationary outer shell. A developer supply supplies a magnetic developer powder including toner to the magnetic brush. A print head is located on the outer shell of the magnetic brush. The print head includes microchannels or magnetic strips for forming a plurality of parallel lines of developer, and transfer electrodes for selectively transferring toner from two or more locations within each line to a receiver moving relative to the print head. The parallel lines of developer are arranged at an angle with respect to the direction of movement of the receiver, thereby effectively increasing the resolution of the print head in a direction perpendicular to the movement of the receiver. A receiver electrode is arranged in spaced relation to the transfer electrodes to define a recording region through which the receiver is moved.

Abstract: A cartridge (10) of web material includes a hollow cartridge body (14) having an exit slit (26); a strip or sheet (12) of web material enclosed in the cartridge body to be withdrawn from or inserted into the cartridge body via the exit slit; at least one magnetic member (38, 40; 130; 172-178; 240; 290,292) carried on the strip or sheet; and a magnetically actuated visual indicator (36) mounted on the cartridge body adjacent the exit slit to be actuated by the magnetic member when the strip or sheet is withdrawn from or inserted into the cartridge body.

Abstract: A method of assembling a print head for an electrographic printer includes the steps of providing a flexible sheet having a microchannel print structure having a longitudinal axis and a plurality of alignment features relative to the longitudinal axis; providing a magnetic brush having a cylindrical axis and an outside shell; providing a fixture having alignment features for aligning the flexible sheet on the outside shell of the magnetic brush such that the longitudinal axis of the microchannel print structure is aligned parallel to the cylindrical axis of the magnetic brush and for conforming the microchannel print structure to the surface of the outside shell; andplacing the flexible sheet and the magnetic brush in the fixture and attaching the flexible sheet to the outside shell of the magnetic brush.

Abstract: An electrographic printer includes: a magnetic brush having a stationary outer shell and a rotating multi-pole magnet within the outer shell; an electrographic print head mounted on the outer shell of the magnetic brush; a Hall effect sensor located adjacent to the magnetic brush for detecting a field produced by the multi-pole magnet parallel to the surface of the shell and producing an output signal; and a pulse control circuit connected to the Hall effect sensor for detecting zero crossings of the output signal and supplying printing pulses to the electrographic print head in response thereto.

Abstract: A magnetic brush development roller assembly for an electrographic printer, includes a cylindrical multipole magnet mounted for rotation about a cylindrical axis within a cylindrical shell. The stationary shell surrounding the multipole magnet defines an axial slot for receiving an imaging head, and has an increased thickness in the neighborhood of the slot and a reduced thickness in a neighborhood diametrically opposite the slot, whereby eddy currents generated by rotation of the magnet within the shell and hence drag on the magnet are reduced.

Abstract: A method for manufacturing a multi-faceted polygon for a laser writer, comprises the steps of creating a plurality of scanning surfaces on the polygon; and creating a step which is positioned on a mounting surface of the polygon for indicating the center of rotation for the polygon.

Abstract: A moving coil linear actuator including an elongated permanent magnet having a cross-sectional width substantially greater than its edge height and having an elongated length of soft magnetic material disposed along one or both edges of the permanent magnet to enhance the magnetic field strength in the gap through which the moving coil translates.

Abstract: A bleachable composition, including an acid photogenerator and a near-infrared radiation-absorbing dye or pigment, is utilized in a method of migration imaging to prevent unwanted absorptions. This composition can be incorporated either in the thermoplastic imaging surface layer of the imaging element, in the marking particles applied to the element, or both. Alternatively, the components of the bleachable composition can be separated with one in the thermoplastic imaging surface layer and the other in the marking particles. After the imaging element is marked and exposed with near-infrared radiation, the bleachable composition caused exposed portions of the imaging element to be bleached. If further bleaching is needed, the element can subsequently be exposed with near-ultraviolet radiation. A migration imaging method, which does not employ the bleachable composition of the present invention, wherein marking particles are magnetically attracted to the imaging element, is also provided.

Abstract: An electromagnetic camera shutter including an electrically conductive shutter blade and electrically conductive springs for urging the shutter blade into a first or a second position from a compressed position between the first and the second position. A permanent magnet is associated with said shutter blade and a control device applies a current through the springs and the shutter blade in a first direction to generate an electromagnetic field between the shutter blade and the permanent magnet so as to move the shutter blade from the first position to the second position and alternately, applies a current through the springs and the shutter blade in a second direction so as to move the shutter blade from the second position to the first position.

Abstract: A fluid bearing includes a rotor and a stator. A DC motor drives the rotator. The DC motor has (1) a multi-phase set of coils on one of the rotor and stator and (2) a multi-pole magnet on the other of the rotor and stator opposed to the coils, the number of magnet poles being an even number which is different from the number of phases and the coils and magnet poles being arranged such that, at a predetermined position of the rotor, at least one of the coils is opposed by only one magnet pole. Commutation selectively applies DC current to the at least one coil, and not to a coil opposed by more than one magnet pole, when the rotor assembly is at the predetermined position of a polarity to cause the at least one coil to repel the opposed magnet pole, creating a magnetic force urging the bearing surfaces apart.