Patents by Inventor Francis H. Gerhard

Francis H. Gerhard 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: 6115114
    Abstract: A laser scanner sensor for measuring the spatial properties of objects in a scene within a range less than a predetermined maximum object distance. Applications of the laser scanner system includes measurement of the dimensional weight of parcel(s) being transported by a moving forklift. In the laser scanner sensor, a laser diode supplies a laser beam that is intensity-modulated by a reference waveform from a waveform generator. A variation of the optical scanning sensor system scans a field of measurement which the moving forklift traverses. The forklift has at least three retroreflectors attached to act as calibration targets within the viewing field.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: September 5, 2000
    Assignee: Holometrics, Inc.
    Inventors: Johnny L. Berg, Francis H. Gerhard
  • Patent number: 5940170
    Abstract: A laser scanner for measuring the spatial properties of objects in a scene within a range less than a predetermined maximum object distance. A laser diode supplies a laser beam that is intensity-modulated by a reference waveform from a waveform generator. An optical scanning system scans the scene with the intensity-modulated laser beam, and receives reflected intensity-modulated light and supplies it to an optical processing system that includes an aperture that transmits a first percentage of light reflected from the maximum object distance and a second, lesser percentage of light reflected from objects closer than the maximum object distance. A photodetector receives the processed light and converts the energy into an amplitude-modulated range signal. A mixer down-converts the frequency into an IF frequency, and a first circuit converts the range signal to the form of a square wave.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: August 17, 1999
    Assignee: Holometrics, Inc.
    Inventors: Johnny L. Berg, Francis H. Gerhard
  • Patent number: 5831719
    Abstract: A laser scanner for measuring the spatial properties of objects in a scene within a range less than a predetermined maximum object distance. A laser diode supplies a laser beam that is intensity-modulated by a reference waveform from a waveform generator. An optical scanning system scans the scene with the intensity-modulated laser beam, and receives reflected intensity-modulated light and supplies it to an optical processing system that includes an aperture that transmits a first percentage of light reflected from the maximum object distance and a second, lesser percentage of light reflected from objects closer than the maximum object distance. A photodetector receives the processed light and converts the energy into an amplitude-modulated range signal. A mixer down-converts the frequency into an IF frequency, and a first circuit converts the range signal to the form of a square wave.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: November 3, 1998
    Assignee: Holometrics, Inc.
    Inventors: Johnny L. Berg, Francis H. Gerhard
  • Patent number: 5422545
    Abstract: A circuit for controlling low wattage gas discharge lamps comprised of a inductive coupling device, e.g., a transformer, a switching transistor, a current sensor, a comparator receiving a signal from the current sensor and driving the switching transistor, and a protective clamp circuit. The primary winding of the inductive coupling device receives a DC voltage and is also connected to the transistor. The transistor allows current to flow through the primary winding causing energy to be stored therein until the current sensor signals the comparator that a first threshold has been reached, the comparator then turns the switching transistor off and the inductive coupling device then enter a fly-back mode where the stored energy is applied to the lamp for a set period of time. The transistor then turns back on and this process is repeated so that the lamp receives a high frequency alternating voltage.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: June 6, 1995
    Assignee: Tek-Tron Enterprises, Inc.
    Inventors: Gerald A. Felper, Francis H. Gerhard
  • Patent number: 4980837
    Abstract: A distinguishable siren sound pattern is produced within an emergency vehicle by automatically alternating the siren sound pattern from among a plurality of distinguishable types of separate siren sound patterns. One of said plurality of distinguishable type of sound patterns may be continuously generated or alternatively through momentary contact in a horn switch, automatically swept among a plurality of the distinguishable siren sound patterns according to a predetermined pattern. In the illustrated embodiment wail, yelp, high-low or hetro siren sound patterns are producible either through microprocessor control or through discretely switched waveform generators. The siren sound pattern is automatically alternated between wail and yelp or between high-low and hetro according to manually switch configurations and momentary activation of a horn ring switch.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: December 25, 1990
    Inventors: Ewing D. Nunn, Francis H. Gerhard
  • Patent number: 4253046
    Abstract: A gas discharge lamp is connected across a step down auto transformer and in series with a solid state switching device and a resistor, and this combination is connected across a rectified AC voltage source. This switching device is controlled by a monostable multivibrator, the input of which is connected to the output of a comparator amplifier sensing the difference between the voltage drop across the above-mentioned resistor and a voltage which may be selected to vary light intensity. A starter aid conductor is placed adjacent the lamp and connected to the grounded side of the voltage source. This results in an efficient, high frequency operation of the lamp wherein the voltage gradient inside the lamp during starting ignition of the lamp is greatly increased to facilitate ignition despite the presence of the step down auto transformer, thereby permitting a decrease in the minimum fly back voltage necessary to start the lamp. As a result, reliability is increased.
    Type: Grant
    Filed: December 11, 1978
    Date of Patent: February 24, 1981
    Assignee: Datapower, Inc.
    Inventors: Francis H. Gerhard, Gerald A. Felper
  • Patent number: 4230971
    Abstract: A gas discharge lamp is connected in parallel with an inductor and in series with a solid state switching device and a resistor, and this combination is connected across a rectified AC voltage source. This switching device is controlled by a monostable multivibrator, the input of which is connected to the output of a comparator amplifier sensing the difference between the voltage drop across the above-mentioned resistor and a voltage which bears a predetermined relationship to the rectified AC signal of said source. This results in a high frequency operation of the lamp wherein the lamp current level is controlled or modulated in accordance with the rectified AC supply voltage, providing a high power factor lamp circuit without the normal heavy lamp ballast. In addition, a circuit is disclosed which prohibits the lamp from exhibiting a high resistance when the AC voltage is at a zero crossing point, protecting the solid state switching device and stabilizing the high frequency.
    Type: Grant
    Filed: September 7, 1978
    Date of Patent: October 28, 1980
    Assignee: Datapower, Inc.
    Inventors: Francis H. Gerhard, Gerald A. Felper
  • Patent number: 4168453
    Abstract: A gas discharge lamp is connected in parallel with an inductor and in series with a solid state switching device and a resistor, and this combination is connected across a DC voltage. This switching device is controlled by a monostable multivibrator, the input of which is connected to the output of a comparator amplifier sensing the difference between the voltage drop across the above mentioned resistor and the voltage of a variable reference voltage source.When the current through the inductor has increased to a point where the voltage drop across the resistor exceeds the voltage of the reference source, the comparator amplifier triggers the monostable multivibrator causing the solid state switching device to be turned off. This acts to collapse the magnetic field in the inductor thereby causing a large voltage to appear across the gas discharge lamp sufficient to light the lamp.
    Type: Grant
    Filed: December 28, 1977
    Date of Patent: September 18, 1979
    Assignee: Datapower, Inc.
    Inventors: Francis H. Gerhard, Gerald A. Felper