Optical Patents (Class 341/13)
  • Patent number: 6501069
    Abstract: A sensor for determining the angular position of a device includes a code disk and a sensor array. The code disk moves in a movement direction in response to rotational movement of the device. The code disk has a digital code including two sets of code tracks extending along the length of the code disk. The corresponding tracks of each track set are spaced apart from one another across the width of the code disk. The sensor array is arranged adjacent to one side of the code disk and across the width of the code disk for sensing the tracks as the other side of the code disk is illuminated to determine the angular position of the device. The sensor provides a reliable indication of the angular position of the device if the digital code is partially contaminated with debris as the digital code contains two sets of corresponding tracks.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: December 31, 2002
    Assignee: Leopold Kostal GmbH & Co.
    Inventor: Frank Blasing
  • Patent number: 6495821
    Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: December 17, 2002
    Assignee: The Chamberlain Group, Inc.
    Inventors: Dane Smith, Chris M. Valente, Martin Rathgeber, Mark D. Siegler
  • Patent number: 6486802
    Abstract: An encoder having a light emitting device and a photo IC for receiving light emitted from the light emitting device. The encoder includes a driving unit having a first driving power output terminal, to which one of a pair of power supply terminals of the photo IC is connected, for outputting driving power. The driving power is used for intermittently driving the photo IC only for a desired time period.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: November 26, 2002
    Assignee: Fujitsu Takamisawa Component Limited
    Inventor: Kazuhiro Watanabe
  • Patent number: 6483105
    Abstract: A rotary actuator includes a motor operatively joined to a gear train having an output shaft. An optical encoder is operatively joined to the shaft of the motor for detecting rotation thereof. A controller is operatively joined to the encoder, and is configured for operating the motor to drive the output shaft between minimum and maximum rotary positions as detected by the encoder.
    Type: Grant
    Filed: February 22, 2001
    Date of Patent: November 19, 2002
    Assignee: Realtime Automation, Inc.
    Inventors: Douglas J. McAllister, Giuseppe D. Cosa
  • Publication number: 20020140580
    Abstract: The present invention relates to a rotary encoder for detecting an angle, and more particularly to an absolute encoder which can read a pattern even when rotating at high speed. The present invention also relates to an encoder reading device that projects a pattern formed on an encoder onto a light receiving means using light emitted from a light source means so as to read a position of the encoder. The light source means is configured to emit a pulse that is synchronized with a shift pulse for moving an electric charge to a transfer gate of the light receiving means, and that is sufficiently shorter than a time interval (accumulation time) of the shift pulse.
    Type: Application
    Filed: April 3, 2002
    Publication date: October 3, 2002
    Inventor: Kaoru Kumagai
  • Patent number: 6459389
    Abstract: The invention relates to an adaptive absolute steering sensor for the absolute determination of a turning angle, especially for determining the steering angle in a motor vehicle by way of a code applied across a 360° angular range for a determining the angle. The code and a sensor system are arranged in such a way that they are able to rotate in relation to each other. Absolute determination of the angle is carried out by reading the contrast information using a micro processor which determines both the angular position of the code and the fine resolution of the angles on the basis of the relative position of the recognized angle to the image on the photodetector system. At the same time the overall function of the system is verified and adjusted during each measurement.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: October 1, 2002
    Assignee: Takata-Petri AG
    Inventors: Michael Germuth-Löffler, Martin Spies
  • Patent number: 6452158
    Abstract: An apparatus for determining the position of a mechanical element wherein the mechanical element is marked in an optically readable manner, comprising reading means to provide a first output dependent on the position of the mechanical element.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: September 17, 2002
    Assignee: J C Bamford Excavators Limited
    Inventors: Mark Lewis Whatley, John Shepherd, Roger William Brassington, Ian Arnold Moore
  • Patent number: 6452512
    Abstract: A method of analog encoder initialization involves repeatedly adjusting an encoder light element energization level and dc offsets of the encoder channels to produce desired signals.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: September 17, 2002
    Assignee: Lexmark International, Inc.
    Inventors: Christopher Alan Adkins, Michael Anthony Marra, III, Jay William Vessels
  • Patent number: 6430479
    Abstract: A method, an apparatus and a computer program product are provided for accurately determining the vertical speed of an aircraft in a manner independent of signals provided by an air data computer, an inertial reference system and an inertial navigation system. Initially, a first vertical velocity of the aircraft is determined based upon a pressure altitude value associated with the aircraft. A second vertical velocity of the aircraft is also obtained from a GPS receiver carried by the aircraft. The first and second vertical velocities are then combined to determine the vertical speed of the aircraft. In this regard, the first and second vertical velocities are combined by complimentarily filtering the first and second vertical velocities. More particularly, the first vertical velocity is typically low pass filtered to remove high frequency noise that is attributable to the relatively low resolution of the first vertical velocity value.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: August 6, 2002
    Assignee: Honeywell International, Inc.
    Inventor: Steven C. Johnson
  • Patent number: 6392224
    Abstract: A scanning unit for an optical position measuring device that includes a detector system that has a first reference pulse signal detector region disposed along a measuring direction and a second reference pulse signal detector region disposed along the measuring direction. The relative disposition of the reference pulse signal detector regions in the measuring direction is selected as a function of the structuring of a reference marking field on a scale for generating a reference pulse signal. An incremental signal detector region is disposed along the measuring direction and between the first and second reference pulse signal detector regions to generate at least one incremental signal.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: May 21, 2002
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventors: Wolfgang Holzapfel, Elmar Josef Mayer
  • Patent number: 6376832
    Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: April 23, 2002
    Assignee: The Chamberlain Group, Inc.
    Inventors: Alan Dane Smith, Christopher M. Valente, Martin Rathgeber, Mark D. Siegler, James J. Fitzgibbon
  • Patent number: 6362469
    Abstract: A rotation detector has a simple structure and operates reliably to check quickly for erroneous installation as an encoder for detecting the rotation rate of a multi-rotation body that rotates for a finite number of revolutions of one revolution or more. A stator member is formed of a housing and a cover coupled together, and a detection window is formed on an outer peripheral wall of the housing. A rotor member is rotatably supported by the housing and the cover, and a rotary ring arranged concentrically with the center of rotation of the rotor member is housed in the stator member. Rotation of the rotor member is intermittently transmitted to the rotary ring via an intermediate gear. According to the variation of outputs from photointerrupters that turn on or off according to the rotation of the rotary ring, an absolute position of the rotor member is detected.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: March 26, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventor: Tadashi Sano
  • 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
  • Publication number: 20010028316
    Abstract: An encoder having a light emitting devices and a photo IC for receiving light emitted from the light emitting device. This encoder comprises a driving unit having a first driving power output terminal, to which one of a pair of power supply terminals of the photo IC is connected, for outputting driving power to be used for intermittently driving the photo IC only for a desired time period.
    Type: Application
    Filed: January 25, 2001
    Publication date: October 11, 2001
    Inventor: Kazuhiro Watanabe
  • Patent number: 6297758
    Abstract: An electrooptical scanning analog-to-digital converter for converting an analog voltage signal from a source to its corresponding digital equivalent in accordance with the invention includes a laser providing a beam having an initial position and multiple deflected positions. The voltage signal forms a deflection input to the laser. A first voltage of the voltage signal provides for the initial position of the beam and multiple other voltages of the voltage signal provide for the plurality of deflected positions of the beam. The invention also includes a phototarget array that has a first phototarget mapped to the first voltage of the voltage signal and multiple incremental phototargets each mapped to one of the multiple other voltages of the voltage signal. The first phototarget and the multiple incremental phototargets are arranged along an axis, which may be in one implementation substantially perpendicular to the initial position of the beam.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: October 2, 2001
    Assignee: Rockwell Collins
    Inventor: Robert H. Sternowski
  • Patent number: 6291815
    Abstract: A device for measuring a rotation angle of a rotary element has first, second and third photo-electric sensors, and a rotary disk having first and second circular arrays of openings, each radial edge of the first array of openings being adapted to be detectable by the first photo-electric sensor so as to generate a first electric signal alternating between “on” and “off” each time when the rotary disk rotates each five times of a unit angle, each radial edge of the second array of openings being adapted to be detectable by the second and third photo-electric sensors so as to generate second and third electric signals, respectively, the second and third signals each alternating between either “on” and “off” or “off” and “on” each time when the rotary disk rotates alternately two times and three times of the unit angle, the “on” and “off” alternations of the first, second and third signals being shifted from one anot
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: September 18, 2001
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Mizuho Sugiyama, Shoji Inagaki, Takashi Kondo
  • Patent number: 6275173
    Abstract: A rotary encoder able to produce a first output signal and a second output signal. The rotary encoder of this invention includes a rotary wheel supported by a frame. An elastic means disposed on the frame provides elastic force to the inside wall of the rotary wheel. A plate is mounted on and rotates with the rotary wheel, and there are a plurality of apertures arranged at a predetermined pitch circularly around an axis of rotation of the plate. An axial rod extends perpendicularly from the center of the plate. Pressure applied to the rotary wheel causes the elastic means to compress and shifts the axis of the wheel and plate such that axial rod contacts a switch and produces the first output signal.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: August 14, 2001
    Assignee: Acer Peripherals, Inc.
    Inventor: Chi-Jung Wu
  • Patent number: 6232595
    Abstract: In a position detecting apparatus which detects an absolute position by A/D converting sinusoidal and cosinusoidal signals and performing interpolation, a phase error between the signals which is caused by movement of a detection object during the A/D conversion is corrected, thereby enabling sample hold circuits which have been necessary for maintaining the synchronism of analog signals to be omitted, so as to realize the cost reduction and miniaturization. This is enabled also in an apparatus of high resolution. Position data at requests of the last and preceding times are stored into a RAM 12. On the basis of the position data, a CPU 10 predicts the amount of a phase shift of another signal due to movement during A/D conversion of one signal, corrects the predicted phase shift amount, and then calculates the position data.
    Type: Grant
    Filed: July 10, 2000
    Date of Patent: May 15, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Okamuro, Hirokazu Sakuma, Yoichi Ohmura
  • Patent number: 6232593
    Abstract: A movable code plate for an optical encoder is given a light path changing function by forming a series of indentations in one or more portions of one surface of the plate. Since these indentation are sufficiently shallow with respect to the thickness of the movable code plate, sufficient strength of the movable plate is maintained. These indentations can be formed on the surface of the movable code plate without a high accuracy. These indentations may be V-shaped grooves or matted surfaces.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: May 15, 2001
    Assignee: Fanuc Ltd.
    Inventors: Mitsuyuki Taniguchi, Masato Aochi
  • 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: 6222183
    Abstract: A mobile code plate manufactured, such as by plastic injection molding, encodes input light by the light path alteration function of a first optical bending portion. This is converted into a first output optical flux by perpendicular incidence and optical transmission at the position of input of a first input optical flux and is then input to a first photodetector element. Since the first optical bending portion arrives at the input position of a second input optical flux, a bent second output optical flux is generated and is likewise input to the first photodetector element. As the mobile code plate rotates, a second optical bending portion arrives at the input position of the first input optical flux. When the first optical bending portion leaves the input position of the second input optical flux, third and fourth output optical fluxes are input to a second photodetector element with the result that an inverted signal is obtained.
    Type: Grant
    Filed: January 6, 1999
    Date of Patent: April 24, 2001
    Assignee: Fanuc Ltd.
    Inventors: Mitsuyuki Taniguchi, Masato Aochi
  • Patent number: 6215119
    Abstract: A low-cost, high precision encoder system includes a codewheel and two encoder sensors mounted at opposite sides of the codewheel to form a dual sensor system having a corrected output that corrects for eccentricity in the mounting of the codewheel and the sensors. The encoder system has a correction circuit that provides a corrected output based on inputs received from the two encoder sensors, which can be single or multiple channel encoders. Methods for achieving the corrected output signal include measuring a time between a signal from the first encoder and a signal from the second encoder and halving this time. Methods for identifying a leading signal from the two sensors are also provided.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: April 10, 2001
    Assignee: Xerox Corporation
    Inventors: Roger Guy Markham, Anthony Edward Audi, Kristin Anne Hughes
  • Patent number: 6194710
    Abstract: An angle measuring device for measuring the angular position of two objects, which can be rotated in respect to each other. The device includes a graduated disk with a graduation and fastened on a hub. A scanning mechanism to scan the graduated disk and a fixation element including an axially extending projection of the hub, which is rigid in the axial direction and elastically resilient in the radial direction so as to fix the axial position relation between the graduated disk and the scanning mechanism, wherein the projection exists in a position of rest where the projection does not contact the scanning mechanism. A pressure element that displaces the projection from the position of rest to a clamping position where the projection clamps the scanning mechanism.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: February 27, 2001
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Johann Mitterreiter
  • Patent number: 6194709
    Abstract: A rotor disk or color wheel received on a shaft to be sensed has an annular band of dual color (red/green) filter material having opposite circumferential gradient. A printed circuit board on one axial side of the rotor disk has the dual color LED, emitting light to a reflector on the opposite axial side of the rotor disk. Some reflected light from the LED passes through the filter which transmits, according to the amount of single color filter material present at the particular rotor station to a photodetector on the circuit board. Other rays of the emitted light are reflected directly to a second detector for ambient compensation. The amount of light transmitted by the filter causes the detector current to vary the charge rate of a capacitor charged to a reference level, and when reached the LED is switched to the other of the dual color emission.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: February 27, 2001
    Assignee: Eaton Corporation
    Inventors: Roger J. Briggs, Lawrence J. Ryczek, Jean-Paul Corbier
  • Patent number: 6191415
    Abstract: A position transducer has a moving modulating portion that can move to various positions through rotation, for example. The position transducer provides at least one analog signal that varies periodically with the moving position of the modulating portion, where the movement of the modulating portion has a period. The analog signal is provided to a converter that converts the analog signal into digital information which is applied to a computing arrangement to provide information as to the position of the modulating portion by using at least one transformation including stored information as to deviations of the periodic variation of the analog signal relative to a sinusoidal shape having a constant amplitude for all periods of movement of the modulating portion.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: February 20, 2001
    Assignee: Stridsberg Innovation AB
    Inventor: Lennart Stridsberg
  • Patent number: 6181423
    Abstract: A linear measurement and control apparatus uses a press roll for directly engraving the surface of a linear control bar and then engaging the control bar which is attached to a machine element, to measure its linear motion and thereby identifying its position. As the machine element moves, the attached control bar transmits its motion to the press roll, inducing rotation. The press roll is attached to a measurement disk having a sensory pickup so that rotation of the press roll is sensed. Light transmission is used for sensing motion of a measurement disk and for counting pulses for determining position.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: January 30, 2001
    Inventor: Jorge Uriarte
  • Patent number: 6172359
    Abstract: An encoder disc (101) of an optical position transducer is mounted on a short protruding part (102a) of a rotor (102) of an electric motor close to torque creating parts. One part of the optical system, normally the light emitter part (108, 115), is insertable between the rotor (102) and the encoder disc (108) after the insertion of the rotor-encoder disc assembly into the motor stator case (113). The optical incremental encoder signals are fed both to a moderate frequency digital counter that counts 4 counts per basic encoder period and to an A/D-converter that samples and digitises the primary encoder analog signals. A synchronising network ensures that the primary encoder digitised signal corresponds to the correct state of the digital counter. More than one decoder head can be used to compensate for the bearing play common in servo motors having varying axial loads.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: January 9, 2001
    Assignee: Stridsberg Innovation AB
    Inventor: Lennart Stridsberg
  • Patent number: 6144027
    Abstract: The present invention is concerned with a steer angle sensor for determining the steer angle in automotive vehicles. Sensors of the afore-mentioned type are required for controlling the driving stability. It is the object of the invention to arrange a code disk in a simple way opposite the housing of the sensor. This problem is solved, in the practice of the invention, in that the code disk is arranged directly on the housing. Advantageous developments refer to possible designs of the bearing.
    Type: Grant
    Filed: April 9, 1999
    Date of Patent: November 7, 2000
    Assignee: ITT Manufacturing Enterprises, Inc.
    Inventor: Petra Weber
  • 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: 6084234
    Abstract: A position transducer is provided that includes an encoder disc and at least two detector devices arranged to read at least one track on the encoder disc having low resolution in order to produce position signals. The detector devices each provide position signals to a processing device having a substantial phase difference therebetween. The signal processing device can determine movements of the encoder disc based upon the signals provided by the detector devices and the detector devices can be energized with a low duty cycle during a low power mode.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: July 4, 2000
    Assignee: Stridsberg Innovation AB
    Inventor: Lennart Stridsberg
  • Patent number: 6078273
    Abstract: The present invention provides a method and apparatus for monitoring an infusion pump (10). The method and apparatus provides an encoder (101) which is used with a motor (65) of the infusion pump (10) and a monitoring method which effectively provides rotational directional information. The present invention utilizes a state transition of a first switch (111) indexed against a constant signal from a second switch (113) corresponding to the center of a flag (117) or sector (119).
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: June 20, 2000
    Assignee: Baxter International Inc.
    Inventors: Geoffrey Hutchins, Tim Allen
  • Patent number: 6054938
    Abstract: A detecting unit provided with an optical system is disposed away from a control unit formed by an electric circuit and an optical transmission/receiving means, and the detecting unit and the control unit are coupled through a transmission optical fiber. The control unit transmits to the detecting unit through the optical fiber a light wave which was subjected to the intensity modulation by a sinusoidal wave of a predetermined frequency. The transmitted light wave is branched into at least two branched optical paths within the detecting unit thereby to perform the phase modulation as to the respective light waves. The light waves passed through the respective branched optical paths are subjected to the phase modulation by the sinusoidal waves which differ in phase 1/4 period by 1/4 period from one another according to a position on a straight line or a rotation angle of a subject to be detected.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: April 25, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hajime Nakajima, Masahiro Shikai, Toru Oka, Toshiro Nakashima, Kazuo Takashima
  • Patent number: 6034668
    Abstract: The present invention relates to computer control devices and, more particularly, to devices for controlling the position of a cursor on a computer display. The invention permits improved technology for cursor control devices. Certain embodiments of devices according to the present invention offer an edge detection system that uniquely identifies the maximum and minimum edges for use in a cursor control device, utilizing improved grating plates. Certain embodiments offer more reliable switch cycle detection in a cursor control device.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: March 7, 2000
    Assignee: Altra
    Inventor: Robert E. Jackson
  • Patent number: 5986584
    Abstract: An apparatus indicating the position of an adjustable lever, such as a control lever in a digital audio console, is described. A frame member constrains movement of the adjustable lever. The lever is operatively connected to an encoder apparatus, such that movement of the lever causes movement of the encoder apparatus to provide an indication of position of the lever within the frame member.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: November 16, 1999
    Assignee: Avid Technology, Inc.
    Inventor: Neal E. Breitbarth
  • Patent number: 5949067
    Abstract: An optical rotary encoder including a rotary substrate and an A, B phase detection pattern formed in the rotary substrate and having light-transmitting holes and light-transmitting grooves. The light-transmitting holes and grooves are apertures used to detect the angle of rotation, direction of rotation, and rotational speed of a drive shaft, and are formed with a constant width w and at a constant pitch p in the outermost periphery of the rotary substrate. The light-transmitting hole, being a slot, is formed slightly inward from the outer peripheral edge of the rotary substrate and tilted in a constant direction and at a constant angle such that an axial line in the longitudinal direction thereof is tilted with respect to a straight line connecting the center of rotation of the rotary substrate and the center between the light-transmitting holes.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: September 7, 1999
    Assignee: Alps Electric Co., Ltd.
    Inventor: Tadashi Sano
  • Patent number: 5939702
    Abstract: A writing implement (10) has an optical reader (20) integrated therewith. The optical reader (20) can include a bar code reader, an optical text reader, or an optical imaging reader. Preferably, a wireless data communication circuit shares an emitter and a detector of the optical reader (20).
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: August 17, 1999
    Assignee: Motorola, Inc.
    Inventors: Mark S. Knighton, David S. Agabra, David D. Drobnis, John M. Vernon
  • Patent number: 5923032
    Abstract: An improved optical encoder with a simplified construction for reliable component alignment and enhanced resolution is disclosed. The encoder includes a housing with locating points, such as studs and shelves, integrally formed on inner surfaces of the housing. The locating points reliably fix the X, Y and Z axis orientation between a light detector and light source assembly. The light source assembly preferably comprises two light detectors on a single board to increase resolution. Additional features of the invention include a sealed housing and a code wheel having two concentric tracks of transmissive slots that are circumferentially offset from each other and an external cable strain relief assembly.
    Type: Grant
    Filed: May 2, 1997
    Date of Patent: July 13, 1999
    Assignee: Oak Industries Inc.
    Inventors: Richard C. Carlson, Edward J. Talbert
  • Patent number: 5856668
    Abstract: A photoelectric position measuring encoder including a scale formed of an electrically non-conductive material and having a graduation, a scanner for photoelectrically scanning the graduation and displaceable relative to the scale in a measuring direction for generating a position-dependent signal, a slide or roller element for supporting the scanner on a scale surface, and an electrically conductive element with which the scanner-supporting scale surface region forms an electrical contact and which is connected to a reference potential.
    Type: Grant
    Filed: April 23, 1997
    Date of Patent: January 5, 1999
    Assignee: Johannes Heidenhain GmbH
    Inventors: Gunther Nelle, Peter Fernsebner
  • Patent number: 5852413
    Abstract: A rotary stage (26) is positionable in precise angular increments that are determined by a virtual absolute position encoder disk (106). The angular increments are determined to a 2,400 arc-second absolute resolution by a bar code scale (110) and to a 0.125 arc-second relative resolution by interpolating interference patterns generated by a diffraction grating-based incremental encoder scale (108). The position encoder may be considered a virtual absolute encoder because as little as 0.66 degrees of rotation is required to know the absolute angular position of the rotary stage. The bar code scale eliminates the need for stop bits and quiet zones, which results in increased bar code resolution. The preferred bar code format includes a continuously abutting series of 15-bar slot position bar code patterns positioned as a single track encircling the encoder disk.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: December 22, 1998
    Assignee: Kensington Laboratories, Inc.
    Inventors: Paul Bacchi, Paul S. Filipski
  • Patent number: 5841132
    Abstract: An optical displacement sensor is used to measure the rotary displacement between two shafts which rotate together. By connecting the shafts together by means of a torsion bar, the sensor may be used to measure transmitted torque. The sensor comprises first and second coaxial discs mounted on the shafts and having slots formed therein. A light source directs light through the slots onto an array of photodetectors and a data processor determines the displacement or torque from the positions on the array of images of the slot edges.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: November 24, 1998
    Assignee: Lucas Industries public Limited Company
    Inventors: Steven John Horton, Adrian Leslie Trace, David Rees
  • Patent number: 5841371
    Abstract: An encoder signal generating device in which a light receiving element (1) is constituted by a one-chip planar type phototransistor array that has a plurality of light receiving portions (21). Thus, this encoder signal generating device needs no amplification circuit. Even when using this encoder signal generating device as a device of the multi-channel type, the size of the light receiving element (1) is reduced, in comparison with that of a conventional light receiving element. Moreover, a highly sensitive encoder signal generating device, which has good S/N characteristics, is obtained.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: November 24, 1998
    Assignee: Tamagawa Seiki Kabushiki Kaisha
    Inventor: Shigeo Seki
  • Patent number: 5837999
    Abstract: In an apparatus for detecting a movement of an encoding member capable of generating simultaneously two light beams which are spaced with a predetermined distance therebetween and which move in synchronization with the movement of the encoding member, a line sensor faces the encoding member such that the two light beams move alternately on the line sensor. The line sensor has a length shorter than the distance between the two light beams so that the line sensor receives a single light beam and outputs position information corresponding to a moving position of the received light beam on the line sensor. A detector detects the movement of the encoding member on the basis of the position information output by the line sensor.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: November 17, 1998
    Assignee: Konica Corporation
    Inventor: Tatsumi Horiuchi
  • Patent number: 5825307
    Abstract: An absolute linear encoder includes an index channel and at least two counter channels. The spacing between markings on the index channel is constant, and the spacing between markings on the first and second channels is predetermined so that the positions of the markings in the first and second channels vary so as to provide a unique signature for each position along the encoder. The linear encoder includes quadrature channels to provide increased resolution and to determine the direction of translation. The encoder is provided with a detector unit to detect positions of the markings in each channel, and a processing unit to calculate an absolute position from the detected marking positions. A method of producing the absolute linear encoder includes selecting spacings for markers in the quadrature, index, first and second channels in order to provide a desired resolution and encoder length.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: October 20, 1998
    Assignee: Perception Incorporated
    Inventors: John Titus, Paul R. Meyer
  • Patent number: 5818038
    Abstract: Angle sensor, in particular for the steering gear of vehicles, with several sensor elements of the same design which are positioned separately in a circumferential direction on a facility which is fastened in a fixed position to the installation aligned at a vertical plane to the axis of the installation on a circular curve concentric with the axis of the installation and which cooperate with a code ring which is coupled to a component of the installation which can rotate around the axis. The angle sensor reduces space requirements and simplifies assembly. The code ring is equipped with n(n>1) geometrically equal code ring segments, each featuring the same codification. The sensor elements and each code ring segment extend over circumferential angle of (360/n).degree..
    Type: Grant
    Filed: November 14, 1996
    Date of Patent: October 6, 1998
    Inventors: Detlev Kerkmann, Maik Frenzel, Horst Sudholz
  • Patent number: 5786593
    Abstract: The present invention relates to a rotary encoder for detecting an angle and more particularly to a rotary encoder having a scale with a plurality of patterns of different cycles formed on the rotor thereof and capable of precisely measuring the angle of the rotor by reading the scale. The rotary encoder is made up of a rotor and a stator. A scale formed on the rotor has a first pattern modulated for a first period and a second pattern modulated for a second period different from the first period and the first pattern and the second pattern are sequentially disposed at equal pitch in the rotating direction of the rotor, and, further, there is provided a scale detection means for reading the patterns of the scale. Modulation of the first pattern and the second pattern may be made by spatial modulation exercised by changing the width of the bars in the scale.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: July 28, 1998
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Fumio Ohtomo, Kaoru Kumagai
  • Patent number: 5774068
    Abstract: A code plate has an m-bit signal track read out in parallel for providing the starting position of an AC servo motor for commencing rotation when power is first turned ON. An n-bit signal track accompanied by an incremental signal track is provided on the code plate with the n-bit track read out serially, converted to pure binary in parallel, and used once rotation of the servo motor commences to provide the initial absolute value of the encoder. To this n-bit initial value is added signals from the incremental track upon continued rotation of the code plate.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: June 30, 1998
    Assignee: Tamagawa Seiki Kabushiki Kaisha
    Inventor: Shigeo Seki
  • 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: 5745057
    Abstract: An adjustment operating apparatus for adjusting an adjusting object, such as sound volume, through an operation by the user which includes an operation device for adjusting an adjusting object so as to increase or decrease through an operation and for inputting an adjustment change amount proportional to the amount of the operation, and a control device for generating an adjustment control signal for adjusting and controlling the adjusting object in response to a signal in accordance with the operation from the operation device, wherein the control device varies the speed of change in which the adjustment change amount is increased from the speed of change in which the adjustment change amount is decreased, making it easy to perform a sound volume adjustment operation.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: April 28, 1998
    Assignee: Sony Corporation
    Inventors: Makoto Sasaki, Akira Shinada
  • Patent number: 5719569
    Abstract: A coder includes a measuring rule (R3) carried by one object and having at least two tracks (X, Y). The tracks are provided with simple marks distributed in a substantially identical manner over the two tracks. At least two specific marks (M1, M2) are located on two distinct tracks. Each mark limit defines a spacing change on the measuring rule. At least two mark readers (LX, LY) are carried by another object, each associated with a track whose marks it detects. A processor is connected to the readers for determining the distance and direction of the movement. The invention is useful in robotics and metrology.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: February 17, 1998
    Assignee: Commissariat a l'Energie Atomique
    Inventor: Miguel Saro
  • Patent number: 5719570
    Abstract: An apparatus indicating the position of an adjustable lever, such as a control lever in a digital audio console, is described. A frame member constrains movement of the adjustable lever. The lever is operatively connected to an encoder apparatus, such that movement of the lever causes movement of the encoder apparatus to provide an indication of position of the lever within the frame member.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: February 17, 1998
    Assignee: Digidesign, Inc.
    Inventor: Neal E. Breitbarth