Magnetic, Inductive Or Capacitive Patents (Class 341/15)
  • Patent number: 6335618
    Abstract: A high-accuracy inductive absolute position transducer system has two members movable relative to each other and includes an amplitude modulating transducer including flux modulators of progressively varying properties. The amplitude modulating transducer includes a transmitter winding and at least one set of receiver windings. An amplitude modulating transducer has a plurality of flux modulator zones distributed along the measuring axis. Flux modulators are formed in at least some of the flux modulator zones. The properties of different flux modulators are varied so as to generate varied flux. A signal generating and processing circuit is connected to the transmitter winding. The flux modulators modulate the inductive coupling based on the relative position between the read head member and the scale member.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: January 1, 2002
    Assignee: Mitutoyo Corporation
    Inventor: Michael Nahum
  • Patent number: 6323786
    Abstract: An absolute-value encoder device for detecting a plurality of rotation quantities is disclosed. An A/B phase forming portion 610 forms an A-phase pulse signal and a B-phase pulse signal, based on light passing through a slit rotating together with a rotary shaft. One period of each of those pulse signals corresponds to one revolution of a rotary shaft. The A- and B-phase pulse signals are displaced in phase by 90° from each other. When an A/B-phase state detecting portion 640 detects a state change of each of those pulse signals, a clock forming portion 66 changes a frequency of a clock pulse signal to another frequency.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: November 27, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hirokazu Sakuma, Takashi Okamuro, Yoichi Ohmura, Yukio Aoki, Toshikazu Satone
  • Patent number: 6311401
    Abstract: This invention relates to a steering angle sensor wherein the angle values are determined by the position of a code disk provided with an incremental track and a code track. So as to be able to express the 8-step-code-word-defined precision by means of six-step code words on the code track the six-step code words are supplemented by 2 bit resulting from the momentary state of the incremental track scanned by two detectors.
    Type: Grant
    Filed: April 15, 1999
    Date of Patent: November 6, 2001
    Assignee: ITT Manufacturing Enterprises, Inc.
    Inventors: Klaus Neckel, Bernd Wigger
  • Patent number: 6304832
    Abstract: The invention provides a method of sampling precision measurement signals to achieve an accurate measurement position at a particular measurement time, such that the measurement accuracy is unaffected by the velocity of motion. The method involves sampling each signal during a predetermined sampling period such that a signal from one sensor is sampled first, a signal from a second sensor sampled second, etc., and then the signals are sampled in reverse order such that the first signal sampled is sampled last. These sampled signals are averaged and produce a precision measurement at a time measured at one-half of the sampling time. In addition, this method can be applied to the use of separate scale tracks where each scale track is alternately sampled, or alternatively, where one scale track is sampled in the middle of the sampling period of another scale track.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: October 16, 2001
    Assignee: Mitutoyo Corporation
    Inventors: Nils Ingvar Andermo, David Skurnik, Mark L. Delany
  • Patent number: 6297750
    Abstract: A linear position encoder is provided which is not affected by ambient light, smoke, moisture, particulate matter, and also not affected by electrical interference such as may be caused by stray fields or permanent magnets or magnetic particles. The encoder comprises a linear scale having an excitation loop disposed along the length of the scale and having electrical terminals preferably disposed at one end of the scale. An alternating current is applied to the excitation loop to create an alternating magnetic field. At least one periodic conductive pattern is provided on an outer side of the excitation loop. The periodic pattern has electrical terminals preferably at the same end of the scale as the terminals of the excitation loop. A sensor is provided on a small printed circuit card that is movable in relation to the scale. The card has a pickup loop which receives energy coupled from the scale excitation loop and which induces current in the periodic pattern.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: October 2, 2001
    Assignee: Dynamics Research Corporation
    Inventors: Sidney A. Wingate, John A. Sotir
  • Patent number: 6294910
    Abstract: A moving target opposite a stationary analog sensor has two sensitive elements delivering two sinusoidal output signals, of equal maximum amplitudes, centered on the same average value, in quadrature and with a period equal to one revolution of the target. A device for processing the two output signals, generates n output signals in-parallel, where n is a positive whole number greater than or equal to 2, for providing the position of a rotating component, connected to the moving target, with a resolution equal to 2n. The processing device includes a generator device, a detection device, a multiplexing device and an interpolation device.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: September 25, 2001
    Assignee: The Torrington Company
    Inventors: Francis Travostino, Alain Bochet
  • Patent number: 6271661
    Abstract: An absolute position transducer system has two members movable relative to each other and includes a code track transducer and at least one fine wavelength transducer. The code track is arranged to form a sequential pattern of base-N code words, where N is greater than two (i.e., non-binary). Each sequential non-binary code word identifies an absolute position of one member with respect to the other at a first resolution. Alternatively, the code track is arranged to form a pseudo-random non-binary code word pattern. In this case, the transducer system compares a non-binary code word with a look-up table to determine an absolute position of one member with respect to the other at a first resolution. In order to generate a non-binary code word pattern, code track transducer employs different-sized flux disrupters, different-sized flux enhancers, or a combination of flux disrupters and enhancers.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: August 7, 2001
    Assignee: Mitutoyo Corporation
    Inventors: Nils Ingvar Andermo, Karl G. Masreliez, Kurt E. Steinke
  • Patent number: 6268721
    Abstract: A detector of position of rotation of a target wheel via the outputs of a differential sensor employing two matched MRs to extract position of rotation information from the target wheel. The target wheel is provided with wide and narrow slots or teeth circumferentially arranged such that, for example, 24 zones are created wherein each zone ranges from the center of a wide slot to the center of a narrow slot, and wherein each zone occupies 15 degrees circumferentially. The two matched MRs of the sensor are powered by matched current sources and matched magnetic biasing and are aligned in the circumferential direction of the target wheel. The MRs generate two angularly offset signals from the passage of a single slot (or tooth) of the target wheel which are input to a signal conditioning circuit. Within the signal conditioning circuit, the two sensor signals are differentially amplified to produce a differential signal whereby the width of the slot is used to encode a binary position pulse.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: July 31, 2001
    Assignee: Delphi Technologies, Inc.
    Inventors: Thaddeus Schroeder, Raymond O. Butler, Jr., Bruno Patrice Bernard Lequesne
  • Patent number: 6249234
    Abstract: A position detector is provided for detecting the relative movement of first and second members which are mounted for relative movement along a measuring path. One of the members comprises a magnetic field generator for generating a magnetic field and the other member comprises first and second conductors which are inductively coupled to said magnetic field generator. The arrangement of the first and second conductors and the magnetic field generator is such that output signals are generated in a first and second receive circuits whose position varies with the relative movement between the two members. In addition to carrying information relating to the relative position between the two members, the signals induced in the receive circuits also comprise information defining the relative orientation of the two movable members, and by suitable processing of the received signals the relative orientation of the two members can also be determined.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: June 19, 2001
    Assignee: Absolute Sensors Limited
    Inventors: David T. E. Ely, Ross P. Jones, James M. C. England, Alexander W. McKinnon, Robert M. Pettigrew, Andrew N. Dames, Andrew R. L. Howe
  • Patent number: 6229302
    Abstract: A method for more accurately sensing the rotational position of a shaft having a toothed sensor wheel with a missing tooth is disclosed. The method includes employing an inductive sensor to produce a signal in response to the passing of the teeth on the sensor wheel. The sensor signal is altered by the geometry of the wheel about a gap formed by the missing tooth in order to correct for residual stored energy in the sensor at this location, and thus correct the signal for the timing measured by a processor in communication with the sensor.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: May 8, 2001
    Assignee: Ford Global Technologies, Inc.
    Inventors: Arthur Joseph Varady, John Michael Kacewicz, Robert Joseph Dalbo, Sheran Anthony Alles, Thomas J. Hermann
  • Patent number: 6226569
    Abstract: A rotary transmitter for registration of the steering angle of a motor vehicle, with a transmitter component (49) on which is provided a coding (51) of a predetermined number n of locally sequentially digital words (Wi) with a width of m bits (b1, b2, . . , Bm) in m adjacent to each other tracks, at least one detector (55) for essentially simultaneous registration of the individual bits (b1, b2, . . . , Bm) of a digital word (Wi), whereby the transmitter component (49) and at least the one detector (55) are movable relative to each other, and with an evaluation unit (11) to which is conducted the signal of at least the one detector (55). The evaluation unit (11) ascertains the absolute position of the transmitter component (49) relative to at least the one detector (55), at least one time, by evaluation of a predetermined number (p) of sequentially detected digital words (Wi), whereby the evaluation unit (11) assigns to a detected p-measure (Wi, Wi+1, . . .
    Type: Grant
    Filed: October 20, 1999
    Date of Patent: May 1, 2001
    Assignee: TRW Automotive Electronics & Components GmbH & Co. KG
    Inventors: Cornelius Peter, Wolfgang Huber, Trevor Stewart, Zdenek Pavlis, Danilo Caratto
  • Patent number: 6172500
    Abstract: A geartooth target providing a consistent magnetic signal for each feature type with unambiguously readable features has three unique 30° segments, each segment ending with a falling edge transition, the segments placed to have a unique pattern of segments every 90°.
    Type: Grant
    Filed: June 23, 1998
    Date of Patent: January 9, 2001
    Assignee: Honeywell International INC
    Inventor: Robert E. Bicking
  • Patent number: 6163746
    Abstract: The device for determining a steering angle of a motor vehicle with a steering column, a steering mechanism and a steering tie rod includes a device for generating a fine signal according to an angular position of the steering wheel, a device for generating a coarse signal according to a number of revolutions through which the steering column has been turned in one or the other direction, and a device for combining the fine signal and the coarse signal to obtain the steering angle.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: December 19, 2000
    Assignee: Robert Bosch GmbH
    Inventor: Matthias Moerbe
  • Patent number: 6160499
    Abstract: A magnetic encoder apparatus comprises a moving disk 5 made of a magnetic substance including a position detection slit track 31 provided with a slit for detecting the position thereof, a magnetic pole detection slit track 33 provided with a slit for detecting the magnetic pole of a motor, and a reference detection slit track 32 provided with a slit for detecting the reference position thereof, magnetic sensors 1 being spaced out the moving disk; bias magnets 2 each provided on the back face of the respective magnetic sensors and situated at where corresponds to the respective slit tracks, and a signal processing circuit 6 for processing a signal from the magnetic sensors.
    Type: Grant
    Filed: October 14, 1999
    Date of Patent: December 12, 2000
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Yuji Arinaga, Koji Suzuki, Satoshi Murakami
  • Patent number: 6157188
    Abstract: A compact, long-range inductive absolute position transducer system has two members movable relative to each other and includes a code track transducer and at least one fine wavelength transducer. The two members include a read head member and a scale member. The phase difference between the phase angles of two fine wavelength transducers may be used to generate an intermediate wavelength. Alternatively, the phase difference between the phase angles of one fine wavelength transducer and the code track transducer may be used to generate an intermediate wavelength. The code track includes sequential n-bit code words. Each sequential code word identifies an absolute position of one member with respect to the other with a first resolution. Each intermediate wavelength includes an integer number of code words greater than or equal to one. Using this relationship, the intermediate wavelength is used to identify the start position (start bit) of the appropriate code word.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: December 5, 2000
    Assignee: Mitutoyo Corporation
    Inventor: Kurt E. Steinke
  • Patent number: 6119357
    Abstract: A scale device 1 includes a base unit 2 comprised of an elongated casing 3 wherein an elongated thin-plate-like scale 4 is secured with the a mid portion of the thin-plate-like scale 4 kept in a floating state and a slider unit 10 slidable relative to the base unit 2. The slider unit 10 has a sensor 15 for detecting magnetic graduations recorded on the thin-plate-like scale 4. A reference sliding member 16 is provided for maintaining a constant separation between the sensor 15 and the recording surface of the magnetic graduations of the thin-plate-like scale 4. A pressing sliding member 17 is provided for pressing the reference sliding member 16 so that the recording surface of the magnetic graduations are perpetually contacted with the reference sliding member 16. A detection head unit 14 is movable telescopically relative to the thin-plate-like scale 4 in a direction along the width of the scale.
    Type: Grant
    Filed: May 19, 1998
    Date of Patent: September 19, 2000
    Assignee: Sony Precision Technology, Inc.
    Inventors: Osamu Ochiai, Ken Onoe
  • Patent number: 6118271
    Abstract: A position encoder is provided for indicating the relative position between first and second relatively movable members. One of the members carries a multi-pole magnetic scale which generates a magnetic field whose magnitude and direction vary with position and the other member carries at least one sense conductor. A saturable magnetic element is located in the positionally varying magnetic field of the magnetic scale and an excitation winding is provided which, when energized, generates a magnetic filed which interacts with the positionally varying magnetic field to cause different portions of the saturable magnetic element to saturate and desaturate at different times. The arrangement of the sense conductor is such that as the magnetic element is driven into and out of saturation, it outputs a signal which is indicative of the position of the magnetic scale relative to the sense conductor.
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: September 12, 2000
    Assignee: Scientific Generics Limited
    Inventors: David T. Ely, Andrew N. Dames, Edward G. Colby
  • Patent number: 6111402
    Abstract: A scanning element for a position measuring instrument. The scanning element includes a first scanning track disposed within a first region and a second scanning track disposed adjacent to the first scanning track within a second region. An electromagnetic field generator generates a homogeneous electromagnetic exciting field within the first region and the second region.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: August 29, 2000
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Peter Fischer
  • Patent number: 6100681
    Abstract: Onto a long rectangular board like base board, first Hall IC's are mounted at specified equal pitches in the longitudinal direction, and second Hall IC's are mounted at the equal pitches from a position shifted by a phase difference of 90 degrees in the longitudinal direction relative to this first Hall IC, and a single rectangular board like field magnet (12) having a length of a half of the equal pitch is mounted, opposite to the first Hall IC's and the second hole IC's, and consequently, a linear encoding device is provided, by which a long positional measurement can be performed, and further, which has a simple arrangement.
    Type: Grant
    Filed: August 3, 1998
    Date of Patent: August 8, 2000
    Assignee: Nippon Thompson Co. Ltd.
    Inventor: Naohito Tsuruta
  • Patent number: 6100822
    Abstract: The present invention discloses an optical sensing system which uses a plurality of detectors installed at various positions next to an optical panel to generate a position signal for indicating the position of the optical panel. The optical sensing system has an optical panel having a plurality of sensing areas each having a plurality of encoding holes arranged in a predetermined direction, a sensing device having a plurality of detectors for detecting movements of the optical panel corresponding to the sensing device, each of the detectors being corresponded to one of the sensing areas of the optical panel for detecting movements of the encoding holes along the predetermined direction and generating correspondent sensing signals, and a control circuit electrically connected to the sensing device for collecting the sensing signals generated by the detectors of the sensing device to form a position signal so as to indicate the optical panel's position.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: August 8, 2000
    Assignee: Primax Electronics Ltd.
    Inventor: Shu-Ming Liu
  • Patent number: 6054851
    Abstract: A high-accuracy inductive absolute position transducer system has two members movable relative to each other and includes a code track transducer and may include a fine track transducer. The code track transducers includes a code track transmitter winding and at least one set of code track receiver windings. Each set of code track receiver windings includes n balanced pairs. Each balanced pair extends along the measuring axis and includes a positive polarity winding and a negative polarity winding. A code track has a plurality of flux modulator zones distributed along the measuring axis. Flux modulators are formed in at least some of the flux modulator zones. A signal generating and processing circuit is connected to the transmitter winding and each balanced pair. The code track transmitter winding and each balanced pair form an inductive coupling.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: April 25, 2000
    Assignee: Mitutoyo Corporation
    Inventors: Karl G. Masreliez, Nils Ingvar Andermo, Kim W. Atherton
  • Patent number: 6014091
    Abstract: A device for detecting faults including sensor failure in a sensor that outputs a substantially binary output signal is described. For fault detection, the various terminals of the sensor are supplied with substantially binary voltages from a fault detection circuit and the changes in the output signal of the sensor that occur as a consequence of the supplied voltages are evaluated for fault detection.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: January 11, 2000
    Assignee: Robert Bosch GmbH
    Inventors: Ralf Noltemeyer, Horst Fuhrmann
  • Patent number: 5977765
    Abstract: An apparatus is provided to determine the speed and direction of a rotating shaft, including a rotor with three circumferentially spaced teeth connected to the shaft. The spacing of the center of the second rotor tooth is wider than the spacing of the center of the first tooth and the spacing of the center of the third tooth is wider than the spacing of the center of the second tooth. A sensor detects the center of each tooth and produces a signal in response thereto. The signal is received by a computer. The computer determines the speed and direction of rotation of the shaft by determining a first time period to reach the center of the first tooth, a second time period to reach the center of the second tooth and a third time period to reach the center of the third tooth.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: November 2, 1999
    Assignee: Ford Global Technologies, Inc.
    Inventors: Patrick William Gibson, Robert Cary Haase, David Andrew Franchock, Bradley Dean Riedle, Charles William Suter
  • Patent number: 5969519
    Abstract: An electrical signal transmitter intended for use in a motor vehicle is disclosed. The signal transmitter is provided with a magnetic sensor device for the detection of various positions of a movable vehicle part. To properly recognize a variety of positions, the movable part is connected with a correspondingly movable magnetic trigger member located on a holder. The trigger member has several magnetic tracks extending in the longitudinal direction of movement of the trigger member. Each magnetic track is provided with alternating N/S pole sections to provide a coding scheme. At least one magnetic field sensitive component is associated with each magnetic track to sense fields generated from the N/S pole sections. The at least one magnetic field sensitive component then generates a signal based on the sensed magnetic fields. The signal is indicative of the position of the magnetic trigger.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: October 19, 1999
    Assignee: Leopold Kostal GmbH & Co. KG
    Inventors: Rainer Steiling, Stefan Garneyer, Kersten Rimke
  • Patent number: 5939879
    Abstract: A magnetic encoder is disclosed that provides a uniform magnetic field which is time modulated at a carrier frequency and space modulated by a repetitive pattern of eddy-current conducting lands that move with variable motion. The time modulation is provided by driving an electrical coil in a resonant tank circuit. The space modulation provides areas of higher and lower magnetic field intensity which change in correspondence with the motion of the conducting lands. The intensity of the varying magnetic field is detected by a series connected pair of stationary coils that are positioned orthogonal to both the direction of the changing magnetic field and the direction of the motion of the conducting lands. The pair of stationary coils yield a differential electrical signal that is representative of the motion of the conducting lands.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: August 17, 1999
    Assignee: Dynamics Research Corporation
    Inventors: Sidney A. Wingate, Christopher W. Liessner, John A. Sotir
  • Patent number: 5933005
    Abstract: An angular position sensor is provided by disposing two sensors proximate a rotatable member. A stationary sensor is located in a fixed position and a movable sensor is pivotable about the center of rotation of the rotatable member. A software routine uses a first output signal from the stationary sensor to calculate the rotational speed of the rotatable member. The software also determines a time offset between the receipt of a signal pattern by the stationary sensor and a subsequent receipt of the same pattern by the movable sensor. Using this time offset and the rotational speed of the rotatable member, the angular difference between the positions of the movable and stationary sensors can be developed. This angular difference is equivalent to the throttle position.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: August 3, 1999
    Assignee: Brunswick Corporation
    Inventor: Jason F. Pugh
  • Patent number: 5929631
    Abstract: A sensing method continuously scans an array of sensing elements and determines positions by converting array peak amplitude information to a time based function. An array of magneto resistive elements responds to a relatively moving magnetic field. The process of scanning the magneto resistive elements is independent of the relatively moving magnetic field. Instead of using only one voltage source to power both the driving logic circuitry and the sensing element array, a separate voltage source for powering the sensing element array is used in conjunction with the solid switch array, thus excluding unwanted noise that originates in the driving logic circuitry.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: July 27, 1999
    Assignee: Ford Global Technologies, Inc.
    Inventors: David Lee Striker, Richard Joseph Hampo
  • Patent number: 5920198
    Abstract: A rotatable rotor 41 and a stator 51 located at a predetermined gap between outer circumferential face of the rotor 41 provided with half-cylindrical inner circumferential face are provided. The both ends of the outer circumferential face of the rotor 41 are provided with a step portion 44 to retain a predetermined gap between the opposing faces of the rotor 41 and the stator 51, and a stopper portion 45 to be abutted to both end faces of the stator in the axial direction. A forcing means 61(plate spring) are also provided to force the stator 51 to the rotor 41 so that the inner circumferential face of the stator is abutted at the step portion 44.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: July 6, 1999
    Assignee: Mitutoyo Corporation
    Inventors: Masamichi Suzuki, Seigo Takahashi
  • Patent number: 5898301
    Abstract: Magnetic poles are regularly spaced along a path to form a magnetic track. Some of the magnetic poles are separated by regular pole junctions aligned uniformly with respect to the path of the magnetic track. At least two of the magnetic poles are separated by a skewed irregular pole junction aligned such that a sensor near an edge of the magnetic track will sense a wide pole and a narrow pole to allow an index signal to be produced.
    Type: Grant
    Filed: April 10, 1997
    Date of Patent: April 27, 1999
    Assignee: The Torrington Company
    Inventors: Mark E. La Croix, A. John Santos, Stephen J. Lyle
  • Patent number: 5841274
    Abstract: A high-accuracy inductive absolute position transducer system has two members movable relative to each other and includes a code track transducer and may include a fine track transducer. The code track transducer includes a code track transmitter winding and at least one set of code track receiver windings. Each set of code track receiver windings includes n balanced pairs. Each balanced pair extends along the measuring axis and includes a positive polarity winding and a negative polarity winding. A code track has a plurality of flux modulator zones distributed along the measuring axis. Flux modulators are formed in at least some of the flux modulator zones. A signal generating and processing circuit is connected to the transmitter winding and each balanced pair. The code track transmitter winding and each balanced pair form an inductive coupling.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: November 24, 1998
    Assignee: Mitutoyo Corporation
    Inventors: Karl G. Masreliez, Nils Ingvar Andermo, Kim W. Atherton
  • Patent number: 5825178
    Abstract: The sensing device for determination of a steering wheel angle of a steering column of a vehicle includes a first coded disk which is read by a first group of receiving devices to form a fine code signal and which rotates at the same speed as the steering wheel. A second coded disk rotates with a fourth the speed of the first disk and has two or more pole change positions which are detected by a second group of receiving devices to form a gross code signal. Hall elements are used as receiving devices. Magnetically coded disks having a predetermined sequence of alternating North and South pole regions are used as the coded disks. These regions are distributed around the periphery of the disk and have different arc lengths. Hall switching devices are used as receivers which cooperate with the magnetic regions of the coded disks.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: October 20, 1998
    Assignee: Robert Bosch GmbH
    Inventors: Ulrich Hipp, Manfred Abendroth
  • Patent number: 5774074
    Abstract: A position encoder system is provided, such system including a code wheel, a pair of sensors, a counter, and a processor capable of identifying the correlation between separately identified markings of the code wheel. The identified correlation is indicative of code wheel accuracy, and thus is used to correct error in any angular position determined using the code wheel.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: June 30, 1998
    Assignee: Hewlett-Packard Company
    Inventors: Eugene A. Cooper, Steven B. Elgee
  • Patent number: 5731702
    Abstract: A rotation sensor includes a binary encoded target wheel and a pair of sensors disposed about the target wheel periphery. One of the sensors provides a signal indicative of the passage of regular angular intervals of the target wheel and the other of the sensors provides binary states corresponding to the regular angular intervals.
    Type: Grant
    Filed: August 21, 1996
    Date of Patent: March 24, 1998
    Assignee: General Motors Corporation
    Inventors: Thaddeus Schroeder, Bruno Patrice Bernard LeQuesne, Raymond Ora Butler, Jr., Anthony Leo Marks
  • Patent number: 5729218
    Abstract: An encoder for measuring a relative position between two objects and including a scale support connected with one of the objects, and a scanning unit displaceable along the scale support and connected with the other of the two objects, either directly or by a carrier, by a coupling having a first coupling part attached to the scanning unit, a second coupling part attached to the other object and a carrier, and a third ball-shaped coupling part located between the facing each other surfaces of the two coupling parts and held in a constant contact with these facing surfaces by magnetic forces.
    Type: Grant
    Filed: March 20, 1996
    Date of Patent: March 17, 1998
    Assignee: RSF Elektronik Ges.M.b.H
    Inventor: Gotthard Lepperdinger
  • Patent number: 5698976
    Abstract: A pointing device includes a plate which is made of a magnetic material and having at least one surface with a regular change in first geometrical configuration along a direction y and a regular change in second geometrical configuration along a direction x which is perpendicular to the direction y, where the change in first geometrical configuration is different from the change in second geometrical configuration, and a coordinate input part slidably provided on the surface of the plate. The coordinate input part comprises a mechanism for generating one of a magnetic flux and magnetic field, and a mechanism for detecting a change in the magnetic flux or magnetic field fed back to the coordinate input part via the plate and generating signals indicating a moving direction and a moving quantity of the coordinate input part on the plate.
    Type: Grant
    Filed: August 21, 1995
    Date of Patent: December 16, 1997
    Assignee: Fujitsu Limited
    Inventors: Takashi Nakajima, Shigemi Kurashima
  • Patent number: 5691646
    Abstract: A rotary encoder 10 is composed of a halfway cylindrical stator 11 and a cylindrical rotor 12. The rotor 12 is disposed coaxial with the stator 11 with a predetermined gap. Plural transmitting electrodes 13 with spiral patterns and receiving electrode 14 with a rectangular pattern are formed on the inner surface of the stator 12. The transmitting electrodes 13 and receiving electrode 14 are formed of a FPC substrate 17 with lead lines 15, 16. On the outer surface of the rotor 12, coupling electrode 18 are formed with a spiral pattern so as to be capacitively coupled to the transmitting electrodes 13 and receiving electrode 14. FIG.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: November 25, 1997
    Assignee: Mitutoya Corporation
    Inventor: Kouji Sasaki
  • Patent number: 5657011
    Abstract: A sensor coil pattern used in combination with a coordinate input apparatus is provided, which is adapted to exactly detecting positions if a noise source such as an converter or an electrically closed conductor exists in the periphery of the apparatus. The apparatus is provided with a sensor surface having a sensor coil pattern of many sensor coils arranged thereon in parallel with each other in position detecting directions, a position indicator, a coil or a resonance circuit incorporated therein and a switching means so connected as to select simultaneously one of a plurality of a sensor coils, wherein said many sensor coils include a predetermined number of sensor coils individually connected to the switching means, said predetermined number of sensor coils including at least one or a plurality of sensor coils counted from one end of the arrangement.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: August 12, 1997
    Assignee: Wacom Co. Ltd.
    Inventors: Kazuhiro Komatsu, Katsuhito Obi
  • Patent number: 5646523
    Abstract: The apparatus for determination of absolute angular position of a steering wheel (w) rotatable through several revolutions includes a fine code disk(2) nonrotatably attached to the steering column (c) and provided with circumferentially distributed code elements (2',2", 2'", . . . ) and circumferentially distributed code element sensors (5) for sensing the code elements (2", 2", 2"', . . . ) to generate fine signals which repeat after each revolution of the steering wheel and are indicative of a relative steering wheel angular position during each revolution; and a coarse code disk (7) provided with at least three code tracks (A,B,C, . . . ) and at least three code track sensors (8a, 8b, 8c , . . . ) for sensing respective code tracks (A,B,C, . . . ) to generate a progressive 3-bit coded signal indicative of the absolute steering wheel angular position over the several revolutions.
    Type: Grant
    Filed: October 23, 1995
    Date of Patent: July 8, 1997
    Inventors: Harry Kaiser, Manfred Abendroth
  • Patent number: 5625289
    Abstract: For detecting the angle of rotation of a shaft, in particular of a gear shift shaft in a gear change box for a motor vehicle, a device is proposed in which a carrier arrangement carries a magnet and in its proximity magnetically sensitive sensors. A screening device, rigidly attached to the shaft, moves in the intermediate space between the magnet and the sensors. This screening device is made from a ferromagnetic material such that the magnetic field permeating the sensors is influenced in a manner whereby the sensors generate a signal that unambiguously identifies the position of the shaft.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: April 29, 1997
    Assignee: Deutsche Automobilgesellschaft mbH
    Inventors: Michael Daetz, Roger Pohlmann
  • Patent number: 5621318
    Abstract: Displacement measuring apparatus for measuring the displacement and movement of an object includes a sensor having an operative surface and circuitry for producing an electrical output signal whose value is dependent upon the area of the operative surface covered by an electrical/magnetic field producing member. The apparatus also includes an elongate, flexible band capable of producing an electric/magnetic field, where the band is attached at one end to the sensor to roll over and cover or unroll from over and uncover the operative surface as the object whose displacement is to be measured is moved. The value of the electrical output signal produced by the circuitry is thus dependent upon the area of the operative surface covered by the band and thus by the position and movement of the object.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 15, 1997
    Assignee: University of Utah Research Foundation
    Inventors: Stephen C. Jacobsen, Michael G. Mladejovsky, John E. Wood
  • Patent number: 5606256
    Abstract: The present invention relates to a linear encoder that does not require the connection cable to be pulled around and has a simple constitution, while also contributing to smooth operation of the moving side as well as reduced size of the apparatus. In addition, the present invention also relates to a guide wherein a guiding device composed of a track rail and so forth is added to the linear encoder. In addition to arranging a plurality of detecting elements composed of electromagnetic conversion elements and so forth at prescribed intervals along the direction of relative motion on the stationary side, a detected element composed of a permanent magnet is arranged so as to oppose the above-mentioned detecting elements on the moving side, thus obtaining the above-mentioned effects.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 25, 1997
    Assignee: Nippon Thompson Co., Ltd.
    Inventor: Seiji Takei
  • Patent number: 5594434
    Abstract: A rotatable member is positioned coaxial with a joint between a first element and a second element. The joint defines an angle to be measured. The rotatable member has coded information thereon. First and second sensing heads are attached to respective elements. Coded information is arranged on the rotatable member so as to periodically pass in readable proximity to the sensing heads once every revolution of the rotatable member. A decoding system is provided for each sensing head. Each decoding system includes threshold circuitry, a state machine, and a pulse generator for providing a timing strobe. A first timer uses a timing strobe from the first sensing head for continuously determining the average elapsed time for one complete revolution of the rotatable member. A second timer uses timing strobes from the first and second sensing heads to continuously determine the average elapsed time for the coded information on the rotatable member to travel from the first sensing head to the second head.
    Type: Grant
    Filed: October 4, 1994
    Date of Patent: January 14, 1997
    Assignee: Rockwell International Corporation
    Inventor: Edward D. McCullough
  • Patent number: 5589768
    Abstract: A magnetoresistance-effect magnetic sensor provides an effective output even in atmospheres higher in temperature than those relevant to prior art sensors. The invented sensor has magnetoresistance-effect devices each connected to a constant current circuit. The voltage across each device is output as a magnetic sensitive output. With this structure, a temperature rise induced decrease in magnetoresistivity of the device is compensated for by an increase in intrinsic resistance thereof attributable to temperature rise. Thus, the sensor provides a reliable output even in high temperature atmospheres.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: December 31, 1996
    Assignee: Mitsubishi Steel Mfg. Co., Ltd.
    Inventors: Noritaka Ishiyama, Koutarou Kobayashi
  • Patent number: 5502380
    Abstract: A magnet mounted on a moving stem or rotary member of a valve generates magnetic flux over part of a stationary member of the valve which has an uniquely patterned set of magnetoresistive sense resistors and three reference resistors (the sensor) disposed thereon. The distance between two adjacent patterns can be equally spaced, or can be compressed for valves with non-linear characteristics in order to achieve increased resolution over a specific portion of the valve travel. Other embodiments can use a light source, beta radiation or neutron radiation as the source of flux, the pattern for each embodiment's sensor having some material responsive and some unresponsive to the flux. The sensor can provide feedback representative of position in a valve positioner, or functions as the position sensor in a position transmitter.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: March 26, 1996
    Assignee: Rosemount Inc.
    Inventors: Fred C. Sittler, Kathryn M. Howard
  • Patent number: 5485468
    Abstract: A data output encoder capable of having its state of retaining internal error information and self-diagnostic information reset without recourse to removing power or furnishing a dedicated signal line. A reset pulse generator monitors the changing status of an externally provided output request signal. When the signal status reaches a predetermined pattern, the reset pulse generator generates reset pulses that cause an RS flip-flop circuit to reset the state in which the internal error information and self-diagnostic information are retained.
    Type: Grant
    Filed: September 11, 1992
    Date of Patent: January 16, 1996
    Assignees: Mitutoyo Corporation, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tetsuro Kiriyama, Mahito Unno
  • Patent number: 5433542
    Abstract: The control device is characterized by including a linear encoder for storing two pieces of information on two phases about a printing position in one storing part located on a longitudinal axis of the linear encoder, reading means for reading the pieces of information on two phases stored in the storing part of the linear encoder, and control circuits for controlling a printing position based on the informations on two phases read by the reading means.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: July 18, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuya Masuda, Kunihiro Kobayashi, Kohichi Sumida
  • Patent number: 5434602
    Abstract: A recording apparatus, which is provided with a carriage supporting a recording head or reciprocating along a platen, includes a magnetized scale of a magnetic linear encoder positioned along a moving direction of the carriage, and a magnetic head of the magnetic linear encoder, mounted on the carriage and adapted for reading the magnetized pattern of the scale. The scale is provided with at least two magnetized lines of mutually different pitches of magnetization, for recording position information relating to the recording operation, and position information relating to other functions.
    Type: Grant
    Filed: April 21, 1993
    Date of Patent: July 18, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshiaki Kaburagi, Shigemitsu Tasaki, Shigeo Takenaka, Makoto Kashimura, Nobuaki Iwakami, Shinya Matsui, Masafumi Wataya, Toshiyuki Onishi, Yasuhiro Unosawa, Hajime Yoshida, Yuichi Hirai
  • Patent number: 5430373
    Abstract: An absolute encoder wherein tracks are arranged side-by-side on a magnetic drum in the axial direction thereof, and absolute patterns of circulatory random sequence codes are divided and recorded on the tracks, respectively. An additional track for generating sinewaves of two phases in synchronism with the reading of the absolute patterns is provided on the magnetic drum, so that an output can be obained by combining a coarse value of an absolute position obtained from the tracks and a fine value of an absolute position obtained from the additional track. The absolute patterns are detected from the two tracks recorded on the magnetic drum by magnetic resistive elements connected with each other to form circuits each having a three-terminal. Terminals of the magnetic resistive elements are connected through a common line with an electric power source in order to prevent the lines from being crossed.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: July 4, 1995
    Assignee: Japan Servo Co., Ltd.
    Inventors: Misao Ichikawa, Kazuo Ohnishi, Tokio Sekiguchi
  • Patent number: 5367581
    Abstract: A document reader, such as a hand-fed check reader is described herein. The reader includes a transducer elastically supported relative to a circuit board. Components and circuitry to manipulate signals produced by (read head transducer), or applied to (write head transducer), the transducers are supported by the circuit board. The transducer is supported by a spring member fabricated from the circuit board material, where the board is mounted relative to a document path of travel such that the transducer is biased against the document. A drive wheel and mechanism is provided to move the document along the path and bias the document against the transducer in the vicinity of magnetic information on the document.
    Type: Grant
    Filed: March 31, 1993
    Date of Patent: November 22, 1994
    Assignee: Direct Data Systems
    Inventors: Jay A. Abel, David B. VanHorn, Jalem M. Getz
  • Patent number: RE34741
    Abstract: A capacitance-type measuring apparatus includes first and second support members which are movable with respect to one another along a measurement axis; a first electrode array and a second electrode disposed on the first support member; and a third electrode array disposed on the second support member and capacitively coupling the first electrode array and second electrode for transmission of a signal between the first electrode array and second electrode through the third electrode array. One of the first electrode array or the second electrode is formed to have end portions configured such that the degree of coupling between the first electrode array and second electrode through the third electrode array decreases linearly along the extent of each end portion relative to the measurement axis. This configuration permits improved measurement accuracies by reducing the effects of tilt between the first and second support members which changes the spacing between such members along the axis of measurement.
    Type: Grant
    Filed: September 24, 1992
    Date of Patent: September 27, 1994
    Assignee: Mitutoyo Corporation
    Inventor: Mils I. Andermo