Patents by Inventor Walter Hrastnik

Walter Hrastnik 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: 4367039
    Abstract: A wet modular film printer having a plurality of removable modules upon which film printer components are mounted including a liquid immersed, capstanless printing head. The printing head immersion liquid is continuously recirculated and filtered by means of a recirculation draw off near the top of the liquid surface and a recirculated liquid return downstream of the printed head. Liquid containing areas are all enclosed and a negative pressure is maintained to remove any noxious vapors. After printing, the liquid remaining on the raw stock and the negative is removed by a series of wipers, an air stripper and a drying column. The drying column uses heated air which flows countercurrent to the direction of film movement so that the air is progressively hotter along the film's path of movement.
    Type: Grant
    Filed: March 11, 1982
    Date of Patent: January 4, 1983
    Assignee: Bell & Howell Company
    Inventor: Walter Hrastnik
  • Patent number: 4155646
    Abstract: A printing head assembly is disclosed for use in a contact film printer for exposing raw stock film with a preprint film or negative. The printing head assembly includes an aperture jaw through which light is projected onto the film strips to transfer the images from the preprint film onto the raw stock. The printing head is adapted to be mounted with the aperture jaw adjacent a drive sprocket for driving the film webs past the aperture in a contact relationship and at a predetermined rate. The edge of the preprint film strip opposite the drive sprocket is supported by a shoulder or idler ring rotatably mounted within the printing head by a stationary support shaft. The support shaft is mounted with its axis extending at a small angle with respect to the horizontal. The rotating shoulder thus rotates in a plane offset from the vertical to permit sufficient clearance for the printing light beam to be projected through the printing aperture.
    Type: Grant
    Filed: December 23, 1977
    Date of Patent: May 22, 1979
    Assignee: Bell & Howell Company
    Inventor: Walter Hrastnik
  • Patent number: 4154528
    Abstract: A modular photographic film printer utilizes a direct current servo controlled main drive motor and belt drive to move a master film and raw film stock across printing heads without the use of intermediate sprockets. Film tension is controlled by tension control motors connected to the pay out and take up reels of the printer. The unit is modular in construction, and circuitry is provided for monitoring critical functions of the printer in order to locate malfunctions. Fiber optics are utilized in the sound track printing head to provide cool operation.
    Type: Grant
    Filed: June 19, 1978
    Date of Patent: May 15, 1979
    Assignee: Bell & Howell Company
    Inventors: Charles J. Watson, Walter Hrastnik, John W. Lang, Jr.
  • Patent number: 4108537
    Abstract: An electro-optic light valve is disclosed which is particularly adapted to be used in an additive color printing system for use on conventional photographic film printers. The additive color system utilizes a plurality of light valves, one for each of the monochromatic light beams, for controlling the color balance and light beam intensity of the printing light beam on the photographic film printer. A programmable, electronic control system is provided for driving the light valves in accordance with programmed color balance and intensity information. Closed loop feedback is provided from the electro-optic light valves to the control system to guarantee accurate execution of the programmed information.
    Type: Grant
    Filed: December 30, 1976
    Date of Patent: August 22, 1978
    Assignee: Bell & Howell Company
    Inventors: Charles J. Watson, Walter Hrastnik