Patents by Inventor David K. Towner

David K. Towner has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5929892
    Abstract: A system and method of providing a periodic trajectory scan path for a laser beam across a photoconductive surface in a laser printer. A preferred embodiment of the periodic trajectory for a system with a two-axis deflector includes a multiple-frequency omega wave trajectory for providing a substantially rectangular grid of available dot locations for selective laser beam pulsing. As such, a plurality of generally linear rows of dots are completed in a single scan pass of the laser beam across the surface. The periodic trajectory is provided by deflecting the laser beam with an optical beam deflector, such as an electro-optic deflector, placed between the laser and the rotating polygon scanning mirror. A preferred embodiment of the beam deflector includes a folded optical path.
    Type: Grant
    Filed: August 26, 1996
    Date of Patent: July 27, 1999
    Assignee: Hewlett-Packard Company
    Inventors: David K. Towner, Daniel R. Marshall, Robert J. Lawton
  • Patent number: 5432763
    Abstract: A miniature rotary actuator optical head assembly incorporating data and servo detecting elements mounted inside a source/detector module, which is located on the rotary actuator arm adjacent to the pivot point of the rotary actuator arm. The miniature rotary actuator optical head also includes a miniature focus motor which supports a fold mirror and an objective lens and repositions the fold mirror and objective lens simultaneously whenever a focus error is received. The focus motor can be actuated by a magnetic bias field that originates external to the rotary actuator arm, particularly the magnetic bias field generated for magneto-optical recordation. The optical assembly may also include two stage tracking by mounting the light source on a pair of lateral movement flexures and supplying a fine tracking error signal to actuate the movement of the light source.
    Type: Grant
    Filed: October 18, 1994
    Date of Patent: July 11, 1995
    Assignee: Hewlett-Packard Company
    Inventors: David K. Campbell, Daniel R. Marshall, David K. Towner
  • Patent number: 5070493
    Abstract: An optical assembly incorporating a wedge-shaped optically transparent prism, a 45 degree right isosceles triangular prism which has two thin film coated surfaces, a rhomboidal prism attached to the triangular prism, a second, smaller 45 degree right isosceles triangular prism attached to one end face of the rhomboidal prism and two planoconvex lenses attached to the combination of the rhomboidal and second triangular prisms is mounted within a housing. All of the optical components are cemented to the adjacent component utilizing a transparent optical cement to form an integral unit.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: December 3, 1991
    Assignee: Hewlett-Packard Company
    Inventors: Daniel R. Marshall, David K. Campbell, Bernard W. Bell, Jr., David K. Towner
  • Patent number: 4688201
    Abstract: A two-stage beam positioning apparatus for use in an optical data storage device is provided. A fixed assembly includes a light beam source and detector, light beam focusing and track following apparatus. The fixed assembly is optically coupled to a movable assembly which provides coarse positioning of a focused light spot on a data storage medium such as an optical recording disc. The coarse positioning assembly is mechanically independent from the light beam source and detector assembly and, therefore, may be made very stiff and light resulting in a high bandwidth and reduced data access time. Since the light beam source and detector assembly and the focusing and track following control apparatus are mechanically isolated from the movable coarse positioning assembly, the size and mass of these components are not critical and do not affect data access time.
    Type: Grant
    Filed: January 16, 1985
    Date of Patent: August 18, 1987
    Assignee: Hewlett-Packard Company
    Inventors: David K. Towner, David K. Campbell