Patents Represented by Attorney, Agent or Law Firm John A. Brady
  • Patent number: 6881272
    Abstract: A method for recycling photoconductors is disclosed. In this method, the charge transport layer is selectively removed from the photoconductor without adversely affecting the electrical properties of the charge generating layer. The recycled drum may then be recoated with a new charge transport layer and reused in an electrophotographic process. In this method, the photoconductor to be recycled is placed in a specifically selected solvent, such as a dibasic ester, and is subjected to ultrasonic energy, preferably for a period not to exceed about 15 minutes.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: April 19, 2005
    Assignee: Lexmark International, Inc.
    Inventors: David G. Black, Weimei Luo Gheleta, Ronald H. Levin, Dat Q. Nguyen
  • Patent number: 6867883
    Abstract: A color gamut in a first color space is expanded to utilize a larger gamut in a second color space. The gamut in the first color space is first converted by black generation or geometric distortion to a gamut in a second color space. The gamut in the second color space is converted by forward mapping to a gamut in a third color. The gamut in the third color space is expanded by linear rescaling. Finally, the linearly rescaled gamut is mapped to a gamut in the second color space through inverse modeling to form a final color gamut. The final color gamut utilizes the gamut available in the second color space, which is larger than the gamut available in the first color space.
    Type: Grant
    Filed: January 21, 2000
    Date of Patent: March 15, 2005
    Assignee: Lexmark International, Inc.
    Inventors: Tomasz Jan Cholewo, Raymond Edward Clark
  • Patent number: 6867286
    Abstract: Provided are novel yellow azo dyes which are useful in ink compositions, especially ink jet compositions. The dyes and ink compositions of the present invention exhibit a good balance of optical density, print reliability, water fastness and light fashion and exhibit improved water solubility, thus rendering the ink compositions to be especially suitable for printheads having small nozzle openings.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: March 15, 2005
    Assignee: Lexmark International, Inc.
    Inventors: Ann P. Holloway, James Frederic Feeman
  • Patent number: 6843838
    Abstract: The present invention provides inkjet inks, dye sets, and inkjet ink sets for use in inkjet printing methods. The inkjet inks and inkjet ink sets of the present invention can provide excellent photo-realistic print quality while achieving a high level of lightfastness. The inkjet ink comprises: a xanthene dye, and a metallized azo dye having the Formula (I). The inkjet ink set comprises: a magenta dye set comprising a xanthene dye, and a metallized azo dye having the Formula (I), at least one yellow ink comprising at least one yellow dye, and at least one cyan ink comprising at least one cyan dye. The present invention also provides a method of printing using the inkjet ink set of the present invention.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: January 18, 2005
    Assignee: Lexmark International, Inc.
    Inventors: Agnes Kam Zimmer, John M. Medley, Vladimir Kantorovich, Wendell Lake, Sandra Helton McCain
  • Patent number: 6836280
    Abstract: A collimation assembly for use in a laser scanning unit is provided. Methods for aligning collimation and pre-scan assemblies in a laser scanning unit are further provided. Also provided are alignment structures for use in aligning collimation and pre-scan assemblies in a laser scanning unit.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: December 28, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Roger Cannon, Christopher Chee, Robert Paterson
  • Patent number: 6833937
    Abstract: A method and apparatus for mapping a color space to a colorant space. The method comprises an operation for selecting a color value from a color space, identifying a color value in a colorant space that minimizes a function parameterized to the color value selected from the color space, and associating the color value selected from the color space with the color value identified in the colorant space. An apparatus for mapping a color space to a colorant space comprises a processing unit, a memory unit coupled to the processing unit, and a software means. The software means is operative on the processing unit for minimizing an error function of a differentiable function capable of mapping a colorant space to a color space to obtain a function capable of mapping the color space to the colorant space. The error function includes a color difference error.
    Type: Grant
    Filed: January 21, 2000
    Date of Patent: December 21, 2004
    Assignee: Lexmark International, Inc.
    Inventor: Tomasz J. Cholewo
  • Patent number: 6822672
    Abstract: A laser printer having a rotating mirror (116) and a heat fuser (220) is operated with a sequence of standby conditions. At the end of a print job mirror (116) is continued to be rotated at printing speed while the temperature of fuser (220) is reduced somewhat. This is maintained for a short time, after which the speed of rotation of mirror (116) is reduced significantly and the fuser (220) temperature is reduced significantly. This is maintained for a time, after which the mirror is no longer rotated (or, if practical, is rotated very slowly) and the fuser temperature is further reduced. At any time when a subsequent print job is received, the mirror and fuser are brought to printing state and the period of times are next started from a beginning state.
    Type: Grant
    Filed: June 24, 2003
    Date of Patent: November 23, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Douglas Anthony Able, Cyrus Bradford Clarke, David John Mickan, Kevin Dean Schoedinger, Thomas Campbell Wade
  • Patent number: 6818290
    Abstract: This invention comprises a fuser belt (1) of polyimide incorporating surface-oxidized boron nitride. The resulting enhanced flexibility provides continuing strength without physical damage during use of the belt in a belt fuser while thermal conductivity is preserved. The extent of flexibility enhancement observed is dependent on the degree of oxidation. Therefore, oxidation temperature and time of oxidation are key variables that are used to control the degree of oxidation and thereby the resulting improvement in the flex fatigue.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: November 16, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Sudha Chopra, Ronald Lloyd Roe, Mark Stephen Weisman, Jr.
  • Patent number: 6819884
    Abstract: Toner transfer in an imaging device having a developer roller (5) that applies toner to a photoconductive roller 7 is determined by counting pels (38) and by counting operating cycles (56). Additionally in the embodiment, various device factors including darkness setting and type of toner are also applied to the totals. An adjustment factor, stored in a toner cartridge memory, is originally substantially one and may be adjusted based on subsequent knowledge or observations of the results. A page count of pages imaged is also used dependently as a second basis for amount of toner transferred.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: November 16, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Philip Scot Carter, William Keith Richardson, Jason Carl True
  • Patent number: 6814793
    Abstract: An ink system comprising a first aqueous ink comprising a cationic pigment dispersion comprising a cationic dye and a pigment, and a second aqueous ink comprising an anionic dispersion comprising an anionic dispersant. The ink system reduces bleed between the two inks when they are applied side by side. The anionic dispersion in the second aqueous ink flocculates the cationic pigment dispersion in the first aqueous ink.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: November 9, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Charles Edward Akers, Mohanram Jayaram, Jing X. Sun
  • Patent number: 6816692
    Abstract: Gear (52) and resin body (2) supported on shaft (1) and between frame members (14a) and (14b) are protected from contacting a frame member. Frame (14a) has a partial hole (22) with an opening (24) and a cavity (26), which is open at the hole (22) and on the side toward the opening (24). A bearing (18) has a inner body (30) which internally is partially circular with diameter substantially the same as opening (22). The outer portion of body (30) forms an outwardly extending nub (34). Wall (36) extends across body (30). The part (38) of bearing 18 opposite body 30 has an extended part (38a) to serve as an electrical contact. A shaft end (Sa) past a circular ledge (3a) is supported by bearing (18). The nub (34) fits in the cavity (26) and the wall (36) defines the proper position of rotation of the bearing. This protects gear (52) from being dislodged from its position on shaft (1).
    Type: Grant
    Filed: May 21, 2003
    Date of Patent: November 9, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Matthew Thomas Kerley, Benjamin Keith Newman
  • Patent number: 6810229
    Abstract: An improved fuser subassembly is provided for electrophotographic printers, in which the detack fingers that separate print media from the fuser hot roll do not make physical contact with that hot roll, and thus are “non-contact” detack fingers. A maximum clearance distance is observed as a relatively tight tolerance between the surface of the hot roll and the tip of the non-contact detack fingers. Both color and mono laser printer products can benefit from this design. Since the finger tips are spaced-apart from the fuser hot roll, the life of the hot roll is increased, and other potential problems are eliminated, such as contamination of the detack fingers, which sometimes cause accordion jams of prior art “contact” detack fingers.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: October 26, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Larry Christopher Coleman, Samuel Winton Holmes, Jr.
  • Patent number: 6809740
    Abstract: Methods and image forming systems for approximating the value of a function given specified values of input data using a sparse lookup table. Individual samples are quantized and rounded up or down to an adjacent lattice point of the lookup table. Rather than performing multiple lookup table accesses, which are required using conventional linear interpolation, the disclosed data processing techniques require as few as one lookup table access per sample. The quantized samples are obtained by truncating one or more least significant bits, designated as masked bits, such that the most significant, or index bits, remain. For each sample, the value of an individual one of the masked bits is examined by comparing it with a corresponding entry in a mask array to determine whether the index bits are to be incremented prior to being used as an index to the lookup table.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: October 26, 2004
    Assignee: Lexmark International, Inc.
    Inventor: Steven Frank Weed
  • Patent number: 6792218
    Abstract: Artificial toner consumption is triggered to minimize the incidence of “conditioned” toner when a comparison of the rate of toner consumption to the mechanical activity of the electrophotographic printing device indicates that the toner consumption rate is too low. The artificial toner consumption operation may be achieved through a dummy print operation where an intentionally un-printed image is formed on a photoconductive drum, but the corresponding toner is routed to appropriate waste toner reservoir(s) and the image is not printed on the recording medium. The dummy print toner may be cleaned from the photoconductive drum without being transferred to an intermediate transfer medium and/or may be cleaned from the intermediate transfer medium, both without transferring the toner to the recording medium. The dummy print operation may correspond to a next normally occurring interdocument gap or a dedicated dummy print period inserted between print jobs.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: September 14, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Stanley C. Tungate, Jr., Cary Ravitz, Thomas G. Twardeck, Albert M. Carter, Jr., Gary A. Denton
  • Patent number: 6787279
    Abstract: The present invention is a random copolymer and its use to compatibilize the components of mixtures of immiscible polymeric materials used in the preparation of toner formulations.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: September 7, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Bryan Patrick Livengood, George P. Marshall, John Melvin Olson
  • Patent number: 6787276
    Abstract: Charge transport layers comprise a charge transport compound and binder including styrene-acrylic resin. Dual layer photoconductors comprise a substrate, a charge transport layer as described, and a charge generation layer.
    Type: Grant
    Filed: June 20, 2002
    Date of Patent: September 7, 2004
    Assignee: Lexmark International, Inc.
    Inventors: David Glenn Black, Ronald Harold Levin, Dat Quoc Nguyen, Bradford Lee Taylor, Vincent Wen-Hwa Ting, Franklin Dilworth Zartman
  • Patent number: 6775498
    Abstract: A bracket to mount a charge roller and a blade against a photoconductive drum within an image forming apparatus. Bracket may include a pair of guides that extend outward to receive the ends of the charge roller. A biasing device may be positioned to bias the charge roller against the photoconductive drum. The guides may include an opening sized to allow the charge roller to move and maintain contact with the photoconductive drum. A mounting surface may be positioned on the bracket for receiving adhesive to mount the blade. In one embodiment, the bracket is constructed of an electrically conductive material such that a charge introduced to the bracket is delivered to the charge roller.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: August 10, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Frank J. Palumbo, Tom E Stickler, David Clay Blaine, David Francis Carter, Matthew Lee Rogers
  • Patent number: 6774923
    Abstract: An optical system particularly useful for color laser printers. Four imaging systems are provided, one for each color, black, magenta, cyan and yellow. Each imaging system has separate pre-scan and post-scan optical assemblies. Two scanning polygons are provided, and each scanning polygon is shared by two imaging systems. Both pre-scan optical assemblies shared by each scanning polygon are provided on the same side of the scanning assembly at substantially similar mirror image angles, to reduce scan image registration errors. The pre-scan and post-scan optical assemblies have improved adjustability.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: August 10, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Christopher Gregory Chee, Daniel Eugene Pawley, Earl Dawson Ward, II
  • Patent number: 6771922
    Abstract: A toner cartridge for use in a laser printer has a toner reservoir or hopper in which an agitator is pivoted by a rotating paddle away from its home position proximate an exit opening and then returned to its home position by a spring exerting a predetermined desired force on the agitator after the agitator ceases to be moved by the paddle. The spring may be a cantilever spring, a torsion spring, or a stamped and formed leaf spring.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: August 3, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Thomas Wilbur Blanck, Mark Duane Foster, Robert Watson McAlpine, Gregory Scott Tigges
  • Patent number: 6767489
    Abstract: Solid rollers of a urethane material are formed in closed mold formed by a tube and two end plugs spaced by a shaft, the latter becoming the shaft for the roller. The closed mold avoids rough grinding to a cylindrical shape, as well as avoiding the resulting waste of material and introduction of defects that arise from rough grinding. The formation of bubbles during injection of the urethane material is avoided by filling the closed mold with carbon dioxide gas prior to injection. The formation of gate marks in the urethane material is avoided by repositioning the end caps after injection to separate the injection gate from the cylindrical cavity. The need to trim the ends of the roller is avoided by providing an annular cavity between the top end cap and the tube that receives excess urethane material to be drawn into the cylindrical cavity as the urethane shrinks during curing.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: July 27, 2004
    Assignee: Lexmark International, Inc.
    Inventors: Peter Wallace Bracken, Terry Cutshall, Wojciech Starski