Abstract: An optical encoder device (100) comprises: an optical emitter (103) for emitting light, the optical emitter (103) having a light emission direction (E); an optical detector (104) for detecting light emitted by the optical emitter (103), the optical detector (104) having a light detection direction (D) which is different from the light emission direction (E); an optical element (109) for controlling an optical path (108) between the optical emitter (103) and the optical detector (104) such that light emitted by the optical emitter (103) can be detected by the optical detector (104); and a free area (113) in the optical encoder device (100) for accommodating a moveable optical encoding unit (112) comprising a plurality of alternating transparent and opaque encoding elements such that the plurality of alternating transparent and opaque encoding elements of the optical encoding unit (112) is able to affect the optical path (108).

Abstract: A photoelectric rotary encoder includes a light source that emits a light beam, a returning section that returns the emitted light beam to a direction opposite to an emitting direction of the beam, and a photodetector that is disposed on a substrate on which the light source is disposed and that detects the returned light beam via a disk having a detection pattern section. The photoelectric rotary encoder detects rotational displacement of the disk based on the detected returned light beam. In this photoelectric rotary encoder, an optical element that lets a stray beam component of the light beam from the light source escape via a side surface of the optical element, is disposed in front of the substrate on which the light source and the photodetector are disposed. The optical element covers the substrate and integrates the optical element and the substrate.

Abstract: In order to provide multiple resolution capabilities in an encoder device with the fewest number of parts, a single circuit board platform is provided with multiple chip buses electrically connected in parallel. Each bus is located adjacent a different code disc track wherein the code disc includes multiple concentric tracks of different resolution. The chip buses are compatible with either a surface mounted or a plug-in mounted encoder module assembled to a printed circuit board platform having alternate disc track read locations provided by separate encoder module bus ports. To change resolution the encoder module chip is simply moved from one bus to an alternate resolution bus on the PC board that lies adjacent a different code disc resolution track. In one embodiment, the PC board is mounted to the housing and the electric motor and the code disc is mounted on the rotary motor shaft in order to provide shaft angle position for electrically controlling the operation of the motor.

Abstract: A scale for a position encoder that includes a first graduation track having a first set of markings that are periodically arranged with a defined graduation period ?, a second graduation track having a second set of markings that are periodically arranged with a defined graduation period ?, wherein the second graduation track is shifted relative to the first graduation track by a distance ?/4. A third graduation track having a third set of markings that are periodically arranged with a defined graduation period ?, wherein the first, second and third graduation tracks are positioned such that at any one time at least one, but never three, of the first, second and third graduation tracks will transmit light directed upon the scale.

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.

Abstract: An all-optical linear feedback circuit for use, for example, as a maximal length pseudo random bit sequence generator includes an all-optical logic circuit that is capable of generating 2N?1 bit maximal length pseudo random bit sequences on an optical channel at high data rates e.g. 80 Gbit/s. In the pseudo random bit sequence generator of the present invention, intensity-dependent phase modulation of at least one included semiconductor optical amplifier (SOA) is implemented. The maximum data rate is limited by the fast gain recovery time of the carriers in the SOA. An optical logic gate of the pseudo random bit sequence generator of the present invention may be constructed using various nonlinear elements that provide ultra-fast intensity-dependent phase modulation.

Abstract: A rotary encoder has a disc, a pair of photo-interrupters, an adjusting member, and a shifting controller. The disc rotates around a rotating axis and has slits that are formed circumferentially at given intervals. Each of the photo-interrupters has a light-emitting device and a photo-detecting device opposite one another, and generates two signals with a phase difference. Each photo-interrupter is pivotable around a pivot coaxial with the rotating axis, and is arranged along the circumferential direction of the disc so as to position the slits between the light-emitting device and the photo-detector. The adjusting member contacts the pair of photo-interrupters, and is movable along a shifting direction corresponding to a radial direction of the disc, so as to engage the pair of photo-interrupters. The adjusting member adjusts a relative position-relationship between the pair of photo-interrupters associated with the phase difference.

Abstract: A system for accurately sensing/determining the position of an uniformly rotating shaft characterized in using a single marker in tandem with a high frequency signal, said system comprising a shaft mounted with a disc having a single marker, an opto-electronic device placed in front of the disc for generating a “marker signal” for every rotation of the disc, a means for producing a high frequency signal for sampling/slicing/slotting the time period between two consecutive marker signals, input terminals of a gating mechanism being connected to the opto-electronic device and the high frequency signal generator and an output terminal being connected to a counter such that the gating mechanism allows the high frequency signal to pass to the counter and said counter being configured for counting the number of pulses in the high frequency signal, a D/A converter connected to an output of the counter for converting the number of pulses counted into an analog signal and optionally, a display mechanism for displaying

Abstract: A method for joining a highly electroconductive core element (2) to a jacket element (1) made of refined steel. In said method, the electroconductive core element (2), such as a copper bar, and the joining agent element (3) are inserted in the jacket element (1), and at least the juncture area of the elements to be joined is thermally treated, so that there is created a metallurgical joint between the electroconductive core element (2) and the refined-steel jacket element (1).

Abstract: An assembly for optoelectronically sensing position includes a light source, a coded element, and a plurality of photosensors. Holes are disposed in the coded element to define a plurality of digital codes. The light passes through the holes in the coded element to illuminate the photosensors. The holes are sized and the photosensors are positioned such that the light is transmitted to more than one of the photosensors through each of the holes.

Abstract: An optical encoder whose environmental resistance is improved by increasing the variety of options of materials for a resin-made code plate thereof. Used as material for at least a code pattern of the code plate of the optical encoder is one which meets the condition that the material has spectral transmittance of 70% or more with respect to detection light and that of 50% or less with respect to partial light (for example blue light) of visible wavelengths in translucent sections. If infrared light having wavelengths between 800 nm and 1000 nm is used as detection light, it is preferable to apply polyetherimide, polyethersulfone or polyphenylsulfone as a colored resin material. These materials are excellent in heat resistance, oil resistance, etc., compared to transparent and colorless materials (PMMA, PC, glass, etc.) which have been conventionally used, and hardly cause melting, deformation, white turbidity, etc., in a harsh environment.

Abstract: A magnetic rubber encoder employing a rubber magnet, of a kind which, within a predetermined range of polarization pitches, the maximum magnetization intensity for the selected polarization pitch can be obtained, is provided. The magnetic rubber encoder 1 includes an annular magnetic member 2 made of a rubber material containing a magnet material and having a plurality of opposite magnetic poles N and S alternating with each other in a direction circumferentially thereof. The relationship between the polarization pitch p of each magnetic pole and the thickness w of the magnetic member 2 is expressed by 0.4 p?w?1.0 p. The polarization pitch p is chosen to be within the range of, for example, 0.5 to 1.5 mm.

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.

Abstract: A rotational phase difference detecting system, a method that is capable of very accurately detecting a rotational phase difference between a plurality of rotating bodies, a machine operating-state monitoring system, and a method employing the rotational phase difference detecting system. The detecting system has a first rotating body with a first mark, a second rotating body with a second mark, a mark sensor for detecting the first mark, a first camera for imaging the second mark when the mark sensor detects the first mark, and a display section for displaying the second mark imaged by the first camera. The rotational phase difference is detected from a position of an image of the second mark displayed on the display section and is thus detected very accurately with a simple construction comprising the mark sensor, the first camera, and the display section.

Abstract: In a detector apparatus, voltage signals of phase A and phase B are mixed, the mixed signal is divided to obtain a low-voltage signal, and the low-voltage signal is integrally smoothed. The integrally smoothed low-voltage signal is added to each of the voltages obtained by smoothing the voltage signals of the phase A and phase B. The results are used as threshold voltages of comparators constituting a wave-shaping circuit. The threshold voltages change in accordance with the voltage signals of phase A and phase B, achieving a high accuracy of binarization even when the voltage signals Sa and Sb have variations.

Abstract: An optical encoder includes a planar surface comprising an insulator material. An optical encoder pattern partially occupies the planar surface. The encoder pattern has at least one continuous geometry and is made from a conductive material.

Abstract: An interpolation circuit and method for interpolating first and second out-of-phase ramp signals are disclosed. The interpolation circuit generates fractional ramp signals from the ramp signals and utilizes four multiplexers and two comparators to compare selected ones of the ramp signals. The comparator outputs are used by a finite state machine to provide a next state for the interpolator from the current state and the comparator outputs. The signals selected by the multiplexers are determined by the current state generated by the finite state machine. The finite state machine also detects a startup condition and determines the correct current state from the comparator outputs when different ramp signals are applied to the comparators. The ramp signals can be generated from out-of-phase signals from an optical comparator. The interpolation circuit generates new out-of-phase signals having a larger number of states per cycle.

Abstract: An optical displacement senor includes a source of optical radiation, a two-dimensional array of radiation detectors, and at least one modulating element disposed between the source and detector. The modulating element has alternating first and second modulating regions circumfrentially spaced around a central axis thereof. The modulating element is displacement relative to the array of detectors so that the detector array forms a two-dimensional image of the first and second regions of the modulating element of array. A data processor is connected to the detector array and is adapted to indentify the orientation of at least two different radially extending edges of regions on the modulating element from the two-dimensional image and also to determine the position of the centre of the element from the determined orientation of the edges.

Abstract: A projection-type rotary encoder is provided which has a light source, an object grating plate in which a substantially fan-shaped object grating for transmitting light is arranged at constant angular intervals in the circumferential direction, a rotary scale plate in which a substantially fan-shaped scale grating for transmitting light is arranged at constant angular intervals in the circumferential direction, and a photodiode grating plate in which a substantially fan-shaped photodiode photosensitive surface grating is arranged at constant angular intervals in the circumferential direction. A scale grating 32A is formed in the rotary scale plate with a shape and size that correspond to a light image of the object grating 31A incident on the surface thereof. A photodiode photosensitive surface grating 33A is formed in the photodiode grating plate with a shape and size that correspond to a light image of the scale grating 32A incident on the surface thereof.

Abstract: An optical position measuring device that includes a measuring graduation and a scanning unit, which moves relative to the measuring graduation along a measuring direction. The scanning unit includes a light source, a transmitting graduation with a graduation period PAT, on which a periodic strip pattern with a strip pattern period PSM results in case of a relative movement between the scanning unit and the measuring graduation. A detector arrangement arranged at a distance DDET from the scanning graduation with a plurality of blocks of individual detector elements, wherein the plurality of blocks are arranged periodically with a detector period PDET in the measuring direction. The transmitting graduation is at the distance u from the measuring graduation, the scanning graduation is at a distance v from the measuring graduation, and the detector period PDET has been selected in accordance with the equation PDET=m*1*Pv, wherein m=(1+DDET/(u+v+DLQ)) and 1=1, 2, 3, . .

Abstract: In one aspect, in a device such as a printer, an encoder system method initializes the system to produce analog output signals that fall outside the detection range of an A/D converter of the system. In another aspect, in a device such as a printer, an encoder system method initializes the system without converting analog signal levels into corresponding digital values.

Abstract: A high-resolution position sensor device for use in precise positioning of servomechanisms, by providing increased resolution using of an encoder mounted on the shaft of a motor, which produces transition pulses through a light-sensitive arrangement using a photodetector. Each time the pulse makes a transition because the groove of the encoder wheel has passed, a reset signal is produced which resets to zero the number of clock pulses which have been measured for that interval between the transition pulses. The transition pulses and the time between them changes with changes in motor speed, while the system clock pulse rate remains fixed. The invention provides a more accurate position sensor, which operates by generating more transition pulses than the encoder itself actually generates. If the encoder produces transition pulses at a given resolution, the sensor device produces output pulses having a higher resolution.

Abstract: An encoder for detecting the angular position of a shaft of an electric motor comprises an encoder disc (101) having tracks (515) sensed by detectors in reading heads (106a, 106b). Analog position signals from the detectors are sampled in sampling circuits (1701-1704) at times given by sampling pulses issued by a device such as a counter (506). The sampled analog values are converted to digital values by a converter (1706) and provided to a local processor (1707) calculating position values. The local processor sends commands to the device (506) to issue sampling pulses at accurately defined times, normally regularly spaced in time. The local processor also receives, from a central processor, read command signals commanding to it provide position values. These read command signals normally arrive rather regularly but are not synchronised.

Abstract: A displacement measurement system and a sheet feed system incorporating the same are described. The displacement measurement system includes a support arm, a roller, and an optical encoder. The support arm has a first end and a second end and is configured to turn about a pivot axis on a pivot located closer to the first end than the second end so that displacement of the first end causes a greater corresponding displacement of the second end. The roller is mounted at the first end of the support arm and is configured to rotate about a roller axis substantially parallel to the pivot axis. The optical encoder has at least one component mounted at the second end of the support arm and is configured to generate signals responsive to movement of the second end of the support arm.

Abstract: An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.

Abstract: An apparatus and method for sensing a rotary switch handling direction of a monitor is disclosed, in which a simple configuration can be obtained and accuracy in sensing a handling direction can be enhanced. The apparatus for sensing a rotary switch handling direction of a monitor includes a rotary switch for outputting voltage levels varied correspondingly depending on a user's handling direction, and a microcomputer for storing the voltage levels output from the rotary switch and comparing the voltage levels with a previously stored voltage change/handling direction table to determine a handling direction of the rotary switch. Since the handling direction is sensed by the voltage level difference for respective contacts, it is possible to exactly sense the handling direction and to relatively obtain a simple configuration.

Abstract: An encoder that includes a sensing device that senses encoding marks on a sensing surface that also includes one or more reference marks. The sensing device generates first and second encoder signals when the encoding marks pass the sensing device. The encoding signals define the direction of motion and degree of movement of the sensing surface. A register stores the position of the encoding surface relative to the sensing device. A controller receives the first and second encoder signals and increments or decrements the digital register based on the received first and second encoder signals. The encoder also includes a reference mark detector that generates a first reference mark signal when the first reference mark passes the reference mark detector. The controller resets the digital value to a first reference value when the encoder receives the first reference mark signal.

Abstract: A high-resolution position sensor device for use in precise positioning of servomechanisms, by providing increased resolution using of an encoder mounted on the shaft of a motor, which produces transition pulses through a light-sensitive arrangement using a photodetector. Each time the pulse makes a transition because the groove of the encoder wheel has passed, a reset signal is produced which resets to zero the number of clock pulses which have been measured for that interval between the transition pulses. The transition pulses and the time between them changes with changes in motor speed, while the system clock pulse rate remains fixed. The invention provides a more accurate position sensor, which operates by generating more transition pulses than the encoder itself actually generates. If the encoder produces transition pulses at a given resolution, the sensor device produces output pulses having a higher resolution.

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.

Abstract: A method for evaluating a code signal generated by an encoder having code and reference tracks. The encoder is interposed between a light and a light sensor and moves relative to the light and the sensor such that the code and reference tracks transmit light from the light onto the sensor. The sensor generates the code signal as a function of the light transmitted by the code track which is received by sensor transducers. The method includes capturing and evaluating the amplitude of a reference signal generated as a function of the light transmitted by the reference track which is received by sensor transducers. A measurement parameter relevant for evaluating the amplitude of the code signal is then adapted on the basis of the evaluation of the amplitude of the reference signal in order to compensate the evaluation of the code signal to changing measurement conditions.

Abstract: An encoder system may determine a plurality of intersection points for first and second encoder output signals produced by an encoder. Each intersection point may be determined by initiating a capture of sample points of each of the encoder signals and then examining the captured sample points.

Abstract: An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.

Abstract: An angle measuring system that includes a drive shaft that rotates about an axis of rotation, an encoder and an encoder attachment system that has a Belleville disk spring that generates a radial pressure with respect to the axis of rotation so as to attach the encoder to the drive shaft.

Abstract: An encoder including a light source for emitting light, a photodetector for detecting at least part of the light emitted by the light source, and an encoder film including a plurality of alternating bars and windows and being located between the light source and the photodetector. The encoder includes a mask including a plurality of alternating bars and windows, the mask being located between the light source and the photodetector. The encoder further includes a spacer located between the mask and the encoder film, the encoder film contacting the spacer to maintain a predetermined spacing between the mask and the encoder film.

Abstract: An apparatus and method for sensing a rotary switch handling direction of a monitor is disclosed, in which a simple configuration can be obtained and accuracy in sensing a handling direction can be enhanced. The apparatus for sensing a rotary switch handling direction of a monitor includes a rotary switch for outputting voltage levels varied correspondingly depending on a user's handling direction, and a microcomputer for storing the voltage levels output from the rotary switch and comparing the voltage levels with a previously stored voltage change/handling direction table to determine a handling direction of the rotary switch. Since the handling direction is sensed by the voltage level difference for respective contacts, it is possible to exactly sense the handling direction and to relatively obtain a simple configuration.

Abstract: An optical encoder assembly for an optical encoder for determining rotation of a rotatable shaft. An encoder housing is non-engageable with the shaft. A receiver plate is attached to the encoder housing, has a first side and a substantially opposing second side, and has a through hole and a window both extending from the first side to the second side, wherein the through hole is engageable with the shaft. An encoder mask is attached to the first side of the receiver plate, has a shaft hole engageable with the shaft, and has a mask grating positioned over the window. A light emitter is aligned to face the first side of the receiver plate and is positioned over the mask grating. A light detector is attached to the second side of the receiver plate and is positioned over the window.

Abstract: In a method for prescribing an essentially linear ramp with a prescribable slope by a quantity, and which is clock-pulse-controlled and which describes the ramp by an increment per clock interval, the ramp is described by a number of regular increments and by at least one first and one second irregular increment. The regular increments exhibit a value corresponding to the prescribable slope. The irregular increments exhibit a value deviating from the prescribable slope. The first irregular increment is a first increment describing the ramp and the second irregular increment is a last increment describing the ramp.

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.

Abstract: A multi-turn rotary encoder that includes a first code carrier connected with an input shaft, a scanning device that scans the first code carrier and generates an absolute position of the input shaft within one revolution, and a digital code word is present at an output of the scanning device and a second code carrier for measuring the number of revolutions of the input shaft. A reduction gear is arranged between and coupled to the first and second code carriers. The second code carrier includes a magnetic body with at least one north and south pole and a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with the magnetic body.

Abstract: An apparatus and method for the multiple detection of optoelectronic signals, especially for detecting the positions of setting elements of flaps, slides, valves, etc. arranged in motor vehicles, to determine the steering angles for controlling driving dynamics, or to determine rotational angles or a linear movement converted into a rotational movement. At least two signal paths extend at an angle relative to one another, with one signal path extending substantially parallel to and under a clock disc and with the second signal path intersecting a sensor element perpendicularly through the clock disc. Signals in the first signal path are deflected by a reflector element underneath the clock disc in the direction towards the sensor element where the coincide with signals in the second signal path.

Abstract: An electronic circuit for measuring the position of a spatially periodic intensity pattern of incident radiation includes an array of detectors (1); two or more correlator units (2, 3) each having arrays of capacitors (12, 13) connected to a buffer (14); and a phase angle computing unit (4). The pitch of the array of detectors (1) is smaller than the pitch of the incident intensity pattern so that the latter is oversampled, yielding high accuracy. The detector outputs (17) are weighted by respective fixed capacitance values (15, 16) which vary periodically along arrays of capacitors (12, 13), and a weighted sum of outputs for each correlator unit (2, 3) is output at its respective buffer (14). The capacitance values (15, 16) of respective correlator units (2, 3) are mutually offset by a predetermined phase shift. The analog computation using capacitor arrays (12, 13) is fast and energy efficient, and can be implemented as a VLSI circuit.

Abstract: A method of converting an analog signal to a digital signal includes (a) filtering the analog signal to the range 0≦fx≦fB; (b) sampling the filtered signal at a rate fS>>fN, where fS is the sampling frequency, fN=2fx is the Nyquist frequency of the sampled signal, and fB≦fS/2 is the constrained signal bandwidth; (c) converting the sampled signal to an optical sampled signal: (d) converting the optical sampled signal from a temporal signal to a spatial signal; (e) illuminating a smart pixel array with the spatial signal; (f) processing the spatial signal with an error diffusion neural network to produce a 2-D binary image; and (g) averaging rows and columns of the 2-D binary image using a digital low pass filter and a decimation circuit.

Abstract: An angular position/position encoder is provided for determining the position of a moving part through evaluation of the direction-specific changes in the measured values recorded and for serial output in binary form of the position determined in this way, wherein all changes in measured values are also added together, independent of the direction of movement, and then output as the result of the total distance or angle traveled.

Abstract: An optical encoder is provided in which a disk is prevented from eccentric rotation. An optical encoder comprises a shaft (2) supported on a bearing (3) in a housing (1), a rotating disk (4) having a code pattern and fixed to the shaft (2), a photodetector element (12) which receives light passing through the rotating disk (4) from a light-emitting element (10) and converts it into an electric signal, and a substrate (13) on which is mounted a circuit for detecting a signal in the electric signal. The shaft (2) is inserted in a hole (4a) opened in the center of the rotating disk (4), the backside of which is seated on a step (2a) of the shaft (2). The optical encoder further comprises a spacer (5) fitted loosely over the shaft (2) and placed on an adhesive (6) spread on the rotating disk (4), a ring (7) for fixing the spacer (5) and the disk (4) tentatively to the shaft (2), and adhesive (8) spread on the spacer (5), the ring (7) and the shaft (2).

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.

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.

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.

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.

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.

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.