Patents Assigned to Levex Corporation
  • Patent number: 9291510
    Abstract: A measuring apparatus includes a sensor unit that includes a coil and a conductive cylinder arranged such that an area of an overlap zone varies as a position of an object changes; a capacitor and a resistor that make up a series circuit with the coil; a voltage applier that applies an input voltage Vi to the series circuit; a phase detector that detects a phase of a voltage Vo across the capacitor; a magnitude detector that detects a magnitude of the voltage Vo; feature data in which the phase, the magnitude, a temperature of the sensor unit, and an area of the overlap zone are associated with one another; and a calculator that calculates the temperature and the area based on the feature data using the phase and the magnitude detected by actual measurement of the voltage Vo.
    Type: Grant
    Filed: January 9, 2013
    Date of Patent: March 22, 2016
    Assignee: LEVEX CORPORATION
    Inventors: Kenichi Onishi, Kenji Yamamoto
  • Patent number: 7046018
    Abstract: A position sensor is provided comprising a coil (1) and an electric conductor (2) or magnetic (3) both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (6), a capacitor (4), a comparator (5) of an inverse output type, and a timing circuit (50a) arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator (5) is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor (6) is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor (6) is varied and when the temperature is at a predetermined degree.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: May 16, 2006
    Assignee: Levex Corporation
    Inventors: Seiji Toda, Naomasa Oshie
  • Patent number: 6914438
    Abstract: A position sensor is provided comprising a coil (1) and an electric conductor (2) or magnetic (3) both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (6), a capacitor (4), a comparator (5) of an inverse output type, and a timing circuit (50a) arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator (5) is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor (6) is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor (6) is varied and when the temperature is at a predetermined degree.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: July 5, 2005
    Assignee: Levex Corporation
    Inventors: Seiji Toda, Naomasa Oshie
  • Publication number: 20030179003
    Abstract: A position sensor is provided comprising a coil (1) and an electric conductor (2) or magnetic (3) both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (6), a capacitor (4), a comparator (5) of an inverse output type, and a timing circuit (50a) arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator (5) is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor (6) is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor (6) is varied and when the temperature is at a predetermined degree.
    Type: Application
    Filed: April 16, 2003
    Publication date: September 25, 2003
    Applicant: Levex Corporation
    Inventors: Seiji Toda, Naomasa Oshie
  • Patent number: 6307380
    Abstract: While a high-frequency pulse is introduced at one end of a parallel conductor which is simulated as in an impedance equivalent state, an impedance mismatch generator is mounted to an intermediate region of the parallel conductor. As the impedance mismatch generator has produced a reflected wave of the pulse, a duration before the reflected wave is received at the one end is measured and multiplied by the propagation speed of voltage to calculate the distance from the pulse introducing point at the one end of the parallel conductor to the impedance mismatch generator.
    Type: Grant
    Filed: October 21, 1999
    Date of Patent: October 23, 2001
    Assignee: Levex Corporation
    Inventors: Eiichi Hirai, Seiji Toda, Naomasa Oshie, Masayuki Miki