Patents by Inventor Bruce W. Maxfield

Bruce W. Maxfield 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: 6091406
    Abstract: An acoustic touch sensing device, comprising a substrate, having a surface; and an acoustic wave transducer, transducing a bulk wave in said substrate propagating through said substrate along an axis intersecting said surface, wherein energy of said bulk wave is coupled to a wave having a converted wave mode with appreciable energy at said surface and propagating along said surface. The device may include a set of scattering centers to couple the bulk wave to a Rayleigh wave or plate wave. The Rayleigh wave or plate wave may be dispersed over a region of the substrate, and analyzed to detect a perturbation indicative of a position of touch.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: July 18, 2000
    Assignee: ELO TouchSystems, Inc.
    Inventors: Shigeki Kambara, Hiroshi Kaneda, Robert Adler, Joel Kent, Bruce W. Maxfield, Masao Takeuchi
  • Patent number: 5636635
    Abstract: A non-contact tonometer is described for measuring the intraocular pressure (IOP) of the eye. An ultrasonic power transducer directs an ultrasonic beam onto the eye and the force generated by the radiation pressure causes indentation or applanation which is detected with an ultrasonic or optical detector. An optical system provides an image of the eye with appropriate alignment beams injected through a beam splitter for positioning the device with respect to the eye. An additional ultrasonic beam may be used to measure the range to the eye. Another optical detector, is utilized to measure applanation or indentation; alternatively, an additional ultrasonic transducer and beam could be used. Operation of the device may be through continuous wave or pulsed excitation of the ultrasound. Feed-back control of the ultrasound power level is possible using an additional ultrasonic transducer for measuring the power levels to augment measurement accuracy.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: June 10, 1997
    Assignee: Massie Research Laboratories, Inc.
    Inventors: Norbert A. Massie, Bruce W. Maxfield
  • Patent number: 5614825
    Abstract: Magnetic flux leakage inspection apparatus systems with independently suspended magnetic sensor blocks. The apparatus includes a magnet and a sensor assembly. The magnet is disposed over a surface of a magnetizable material under inspection for inducing magnetic flux in the material, and the sensor assembly is disposed in a predetermined inspection position over the surface for detecting magnetic flux leakage from the material that may indicate a magnetic anomaly in the material. The magnet and sensor assembly are moved along over the surface while the sensor assembly scans for magnetic leakage flux. The sensor assembly is formed with one or more independently suspended sensor blocks, each block including a plurality of sensors rigidly held in the block for detecting magnetic flux leakage.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: March 25, 1997
    Assignee: Industrial Sensors and Actuators
    Inventors: Bruce W. Maxfield, Pamela C. Fitzgerald
  • Patent number: 5514956
    Abstract: Tank bottom inspection apparatus of the magnetic flux leakage type having a powered release mechanism for reducing the magnetic attraction of the apparatus to the tank bottom. The apparatus is wheeled over the tank bottom surface and includes a magnet assembly disposed over the surface for inducing magnetic flux in the material under inspection and a sensor assembly for detecting magnetic flux leakage from the material indicative of magnetic anomalies. A powered actuator permits the operator to retract the magnet assembly away from the surface, reducing the magnetic attraction to the surface and thereby reducing magnetic resistance to movement of the apparatus over the surface. The operator retracts the magnet assembly for maneuvering the apparatus over and around obstacles on the surface with greatly reduced magnetic attraction to the surface. The operator is then able to return the magnet assembly to a precise inspection position for continued inspection of the surface.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: May 7, 1996
    Assignee: Industrial Sensors and Actuators
    Inventors: Bruce W. Maxfield, Pamela C. Fitzgerald
  • Patent number: 5396888
    Abstract: A non-contact tonometer is described for measuring the intra-ocular pressure (IOP) of the eye. An ultrasonic power transducer directs an ultrasonic beam onto the eye and the force generated by the radiation pressure causes indentation or applanation which is detected by ultrasonic or optical means. An optical system provides an image of the eye with appropriate alignment beams injected through a beam splitter for positioning the device with respect to the eye. An additional ultrasonic beam may be used to measure the range to the eye. Another optical means is utilized to measure applanation or indentation; alternatively, an additional ultrasonic transducer and beam could be used. Operation of the device may be through continuous wave or pulsed excitation of the ultrasound. Feed-back control of the ultrasound power level is possible using an additional ultrasonic transducer for measuring the power levels to augment measurement accuracy.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: March 14, 1995
    Assignee: Massie Research Laboratories, Inc.
    Inventors: N. A. Massie, Bruce W. Maxfield