Abstract: A system for programming and controlling the movement of a probe of a voice coil actuator along a path includes a control module that is mounted on a voice coil actuator. Specifically, the control module is connected to a clock and to an encoder to selectively establish a plurality of sequential positions for the probe. Each position in this sequence is defined by a location on the path (translation and rotation), and a time at the location. More specifically, the control module includes a key pad for inputting data to identify each position and also, there is a display for providing a visual presentation of the data. In operation the plurality of sequential positions specify a work cycle for the probe and the voice coil actuator uses the input data to perform a series of work cycles.

Abstract: In the control system, a propulsion force is computed by a propulsion force computing unit based on a current command value outputted from a speed controller, an acceleration is computed by an acceleration computing unit based on the propulsion force and a running resistance outputted from a running resistance computing unit, a speed is computed by a speed computing unit based on the acceleration, and a simulated phase reference value is computed by a phase computing unit. Then, the simulated phase is computed by adding, at a simulated phase computing unit, a predetermined phase delay (e.g. 30 degrees) to the simulated phase reference value. The addition of the phase delay results in generation of synchronizing force in the LSM and thus little deviation between the simulated phase and the actual phase.

Abstract: A system and method for moving a horizontally sliding portal closure includes a linear reluctance motor or a magnetic stepper motor and a reaction piece. The reaction piece is attached to the portal closure such that activation of the stationary mounted linear induction or magnetic stepper motor causes movement of the reaction piece which, in turn, opens or closes the portal closure.

Abstract: A movable stage device, which has a stationary base, a movable stage and a linear motor, further includes a second linear motor which serves as a second driving device for imparting thrust to the movable stage and which is attached to the movable stage through the intermediation of an attachment plate. Both ends of a row of second drive coils are supported above the floor by support plates, which are independent of the stationary base and directly support the row of second drive coils above the floor in such a manner as to provide high rigidity, thereby attaining an improvement in speed and accuracy of positioning and avoiding a waste of energy.

Abstract: A linear compressor driving device for linear compressor driving a piston in a cylinder by means of a linear motor to generate a compressed gas, has an inverter for outputting an alternating current to be supplied to the linear motor; current detecting means for detecting an output current from the inverter; voltage detecting means for detecting an output voltage from the inverter; current amplitude value determining means for determining a current amplitude value of the output current; output power calculating means for calculating an output power from the inverter based on the detected output current and the detected output voltage; frequency determining means for determining a frequency of the output current such that the output power is maximum; and inverter controller for controlling the inverter based on the determined current amplitude value and the determined frequency.

Abstract: An apparatus for protecting a linear motor having a structure in which permanent magnets and a coil are subjected to relative movement, comprising (a) a means for detecting current flowing through said coil, (b) a multiplying means for calculating the squared value of the detected current every constant time &Dgr;t, (c) a memory means receiving said squared values for successively storing said squared values from the first one to the nth one, the first squared value being eliminated when the (n+1)th squared value is input, and the same operation being repeated subsequently, (d) an adding means for calculating the total of n squared values in said memory means, (e) a means for setting a reference value, which is to be compared with the total of said squared values, (f) a means for comparing the total of said squared values with said reference value for outputting an overload signal when said total has become larger than said reference value, and (g) an overload-preventing means receiving said overload sig

Abstract: An apparatus for controlling cooling of a linear motor includes: a stator having a first temperature sensor, a heat sink and at least one cooling fan installed at a predetermined portion thereof; a mover having a second temperature sensor and a heat sink installed at the upper surface thereof; an encoder for sensing a position of the mover and generating a position signal; an A/D converter for receiving and converting signals from the first and the second temperature sensors and outputting a first and a second temperature sensing signals; a controller for generating a plurality of cooling fan control signals and an air valve control signal to cool the heat generated from the stator and the mover; a D/A converter for converting the plurality of cooling fan control signals and the air valve control signal and transmitting a plurality of drive signals to the plurality of cooling fans and to the air valve; and a mover driver for providing a drive signal to a coil block.

Abstract: A multi-phase linear motor (1) that comprises a number of magnets (2i) side by side with multiple phase coils (3i) in which alternating currents that are offset by a predetermined value are made to flow, whereby the interaction between said magnets (2i) and said phase coils (3i) causes a relative linear displacement of magnets (2i) with respect to phase coils (3i). In the linear motor in question, said phase coils (3i) lie on an axis (L) that is perpendicular to the direction of motion.

Abstract: An electrostatic microactuator, known as a “Scratch Drive Actuator” or SDA, is based on a collective set of distributed elementary SDAs of small size that are associated with one another and that integrates a large number so as to allow the addition of the forces generated by each of the SDAs in the collective set. An external mechanical prestress, formed by a homogeneous external pressure in the form of a bias voltage applied at rest to the associated SDAs, is applied to the SDAs to allow a superposition of the forces generated by the associated SDAs. This is done while communicating to an external load the entire driving force emanating from the collective behavior of the SDAs. The electrostatic attraction forces established by the bias voltage are used to calibrate an individualized prestress for each actuator involved in the collective set.

Abstract: An encoder includes a plurality of magnetic zones of alternating polarity. At the opposed ends of the encoder magnet are magnetic end zones that provide substantially symmetric magnetic fields. The encoder sensors include first and second sensors that are spaced apart from each other a distance functionally related to the distance between the magnetic end zones. A plurality of first and second sensors are arranged so that the encoder magnet may move relative to the sensors. Each of the first and second sensors provides an associated output signal in response to magnetic influence of the encoder magnet moving past each respective encoder sensor. When each of the first and second encoder sensors senses one of the magnetic end zones of the encoder magnet, the associated output signals are substantially symmetric.

Abstract: A stage system includes a movable stage, a position measuring device for measuring the position of the stage, a velocity sensor for detecting the velocity of the stage, and a control unit having a position feedback loop based on an output of the position measuring device and a feedback loop for applying a damping to the stage on the basis of an output of the velocity sensor. With the addition of the feedback loop for applying the damping to the stage by using an output of the velocity sensor, a strong braking function is provided, such that the positioning settlement time can be shortened.

Abstract: An electrical driver (10) for a linear electrical motor which drives a linear refrigerant compressor (11) that has a resonant frequency includes a sensor (22) for measuring the magnitude and polarity of the back EMF of the electrical motor at the beginning and/or end of the stroke of the compressor (11). A control circuit (12) analyses the measured back EMF to determine whether the driver frequency is higher or lower than the frequency of the compressor (11) and then adjusts the frequency of the driver (10) to or closer to the resonant frequency of the compressor (11).

Abstract: The linear actuator with movable magnets includes a cylindrical inner yoke; a magnet holder disposed concentrically with the inner yoke via a clearance; a first and a second cylindrical magnets which are magnetized in the radial direction and held by the magnet holder in the axial direction; and an outer yoke disposed concentrically with the inner yoke. The magnetized directions of the two magnets are opposite to each other. The outer yoke has a first and a second coil-disposed sections, around which a first and a second driving coils are wound, respectively. The outer yoke also has a plurality of magnetic pole sections that oppose, via a clearance, to at least one of the first and the second magnets. Besides, in the actuator, dimensional requirements are defined for the magnetic pole and the magnets.

Abstract: A stage apparatus includes a movable stage, a base supporting the stage on a reference plane, a driving mechanism for driving the stage, and a rotor acting on the stage and producing a moment so as to reduce a reaction force produced along with the movement of the stage. The rotor also reduces the reaction force produced upon movement of the stage by the movement of the base and the rotation of the rotor.

Abstract: A method and an apparatus for operating a magnetically levitated magnet vehicle (5) are described, with a synchronous long stator linear motor, which comprises a plurality of winding sections (3.1 3.5) arranged one after the other in the direction of travel (x) and connected one after the other to a track cable (9) in accordance with the progress of the magnet vehicle (5). In accordance with the invention, on passing a changeover point (22.1-22.4), at least the two winding sections (e.g. 3.2, 3.3) adjoining the changeover point are connected electrically in series (FIG. 3c).

Abstract: A force control system for an electromagnetic actuator includes an observer that outputs signals representing the instantaneous position and velocity of a movable member, and a position controller that receives the output of the observer and signals representing a desired position and a desired velocity. The position controller compares the output of the observer with the desired position and velocity signals to generate position and velocity error signals. The position controller further generates force command signals required to position the movable member at the desired position with the desired velocity based on the position and velocity error signals. The position component may be eliminated from the force command signals, resulting in controlling only the velocity of the movable member.

Abstract: A system for programming and controlling the movement of a probe of a voice coil actuator along a path includes a control module that is mounted on a voice coil actuator. Specifically, the control module is connected to a clock and to an encoder to selectively establish a plurality of sequential positions for the probe. Each position in this sequence is defined by a location on the path (translation and rotation), and a time at the location. More specifically, the control module includes a key pad for inputting data to identify each position and also, there is a display for providing a visual presentation of the data. In operation the plurality of sequential positions specify a work cycle for the probe and the voice coil actuator uses the input data to perform a series of work cycles.

Abstract: A ripple suppressor/compensator useful in the general area of motion control and applicable to a wide range of servomechanisms exhibiting a force ripple characteristics, including the permanent magnet linear motors. An adaptive feed-forward control signal is generated which compensates for the ripple force, thus allowing for more precise tracking performance to be achieved.

Abstract: In order to reduce the electrical losses caused by current displacement in conductors in a conductor configuration having a number of electrical conductors for carrying power to, and away from, a winding configuration, which has a number of windings, in an electrical machine, in particular a generator, the respective conductors for carrying power to and away from a respective winding are adjacent to one another. The magnitude of the difference between the phase angles of current vectors of a conductor pair is thus as large as possible, and, in particular it is 180°.

Abstract: In the control system, a propulsion force is computed by a propulsion force computing unit based on a current command value outputted from a speed controller, an acceleration is computed by an acceleration computing unit based on the propulsion force and a running resistance outputted from a running resistance computing unit, a speed is computed by a speed computing unit based on the acceleration, and a simulated phase reference value is computed by a phase computing unit. Then, the simulated phase is computed by adding, at a simulated phase computing unit, a predetermined phase delay (e.g. 30 degrees) to the simulated phase reference value. The addition of the phase delay results in generation of synchronizing force in the LSM and thus little deviation between the simulated phase and the actual phase.

Abstract: A system and method for moving a horizontally sliding portal closure includes a linear induction or a magnetic stepper motor and a reaction piece. The reaction piece is attached to the portal closure such that activation of the stationary mounted linear induction or magnetic stepper motor causes movement of the reaction piece which, in turn, opens or closes the portal closure.

Abstract: An optical actuator includes pairs of stators disposed parallel to each other with a stipulated gap between them, a mover disposed moveably within the gap, and a number of photovoltaic devices. The photovoltaic device has device electrodes on either end in the direction of polarization, each connected to one of the pair of stators. The voltage generated by the photovoltaic effect of the device is utilized to generate force that displaces the mover with respect to the stators by means of electrostatic force arising from the voltage.

Abstract: A control system for a linear actuator having an electric motor drawing a variable current level during operation. The control system includes a current level sensor for determining an operational current level of the linear actuator and a controller for generating a drive signal and a force request signal representative of a desired current level of the linear actuator. The drive signal remains constant during a predetermined time interval of the controller. The control system further includes a current limiting component for receiving the force request signal, the current level of the linear actuator and the drive signal. The current limiting component minimizes the current level of the electric motor in response to a comparison between the force request signal and the desired current level within a time interval substantially smaller than the predetermined time interval of the controller.

Abstract: A linear guide apparatus with magnetic distance sensor is disclosed. A magnetic tape is adhered right on the upper surface of the guide rail so as to minimize the variation of distance between the magnetic tape and a magnetic induction element to assure high distance sensing sensitivity when the slide block is exerted by a transverse thrust force. The magnetic tape can be adhered to the upper surface of the guide rail after the guide rail has been assembled to its base thereby facilitating the assembly work. The magnetic induction element is installed in an end cap of the slide block so that it is not necessary to modify the construction of the inner part of the slide block. As a result, the space is saved and the mechanical strength of the apparatus is increased.

Abstract: A current interrupter (4) includes a current interrupting device (4) having at least one movable contact (71); an actuator (8) coupled to the movable contact (71) of the current interrupter (4); a feedback sensor (14) for monitoring movement of the actuator (8); and a control system (12) coupled to the feedback sensor (14) so as to receive information from the feedback sensor (14) concerning the movement of the actuator (8) and for controlling movement of the actuator (8) based on the information. The interrupter (4) further includes a memory (202) for storing a desired motion profile of the actuator (8); and a microprocessor (202) for comparing the movement of the actuator (8) with the desired motion profile and controlling movement of the actuator (8) based also on a comparison of the movement of the actuator (8) with the desired motion profile.

Abstract: A sliding means with built-in moving-magnet linear motor is provided, realizing high-speed operation and much response ability of a table to a stationary bed, and also accurate position control of the table to the bed. With the sliding means of this invention, armature windings carry a three-phase current while a driving circuit is transferred to the external driver to make the bed slim in construction. Thus, the sliding means is reduced in overall height. A field magnet of rare earth permanent magnet is effective in raising flux density, thereby providing high propulsion for the table. An encoder to monitor a position of the table is an optical encoder having an optical linear scale, which contributes to improvement in accurate monitoring. The construction in which the armature windings connected to cords, lines, and so on are placed on the stator side has no fear of causing dust and dirt, thus realizing clean environment.

Abstract: A positioning apparatus includes a movable member, an actuator for driving the movable member in a moving direction, a gravity guide having a reference surface for supporting the movable member in a gravity direction, a yaw guide for guiding the movable member from one side thereof in the moving direction by means of a guide surface perpendicular to the reference surface, and a measuring device for measuring a position of the movable member in the moving direction. A distance from a measuring position at which the measuring device measures the position of the movable member to the guide surface is longer than a distance from a driving position at which the actuator drives the movable member to the guide surface.

Abstract: A scanning framing blade apparatus includes a stationary assembly having a plurality of magnets; first and second carriage assemblies that each have a plurality of coils. The first and second carriage assemblies are supported on the stationary assembly by a plurality of air bearings that permit the first and second carriage assemblies to move in only one degree of freedom. In addition, the scanning framing blade apparatus includes first and second framing blades that are attached to the first and second carriage assemblies, respectively. The scanning framing blade apparatus also includes a controller that is coupled to the plurality of coils. The controller is adapted to energize at least one of the plurality of coils, thereby causing at least one of the carriage assemblies and corresponding framing blade to move in the one degree. This motion controls illumination onto a reticle during a substrate scanning process.

Abstract: A method of controlling a mounting unit having a shaft operated under servo control using a current driven actuator, comprises the steps of detecting interrruption of the servo control, and switching from a positioning control mode to a constant current control mode for supplying an constant amount of current to the shaft actuator to suspend the shaft. In an embodiment the method further includes engaging a gripping device, for holding the shaft, so as to keep the shaft from free-falling when interruption of the servo control is detected, and maintaining the constant current control mode at least until the gripping device grips the shaft. Still further, the current control mode optionally includes the steps of maintaining the supply of the constant amount of current for a predetermined period of time, and disengaging power supplied to the actuator after the predetermined period of time has elapsed.

Abstract: A propulsion system for a magnetically levitated vehicle is described. The propulsion system includes a drive and/or suspension magnet arrangement mounted in the vehicle, its drive magnets and/or suspension magnets being arranged with their magnetic axes that connect the two magnet poles running across the longitudinal direction of the guideway so that the magnet poles arranged in succession in this longitudinal direction have the same polarity.

Abstract: A method of controlling velocity of an armature of an electromagnetic actuator as the armature moves from a first position towards a second position is provided. The electromagnetic actuator includes a coil and a core at the second position. The coil generates a magnetic force to cause the armature to move towards and land at the second position. A control method is provided to ensure a near zero velocity landing of the armature in the second position while compensating for non-ideal external influences on the system.

Abstract: In a component mounting apparatus, a component (8) is held, positioned and mounted at a predetermined position of a member (4) to be mounted. After the component (8) is mounted to the member (4), a component holding member (5) is raised by a distance corresponding approximately to a push-in amount by which the component holding member (5) has been moved down to mount the component, then stopped to retain the component (8), is kept in this state while retaining the component for a fixed time, and is raised again to a predetermined position.

Abstract: A stage apparatus for moving a table, on which a work is carried, of a semiconductor producing equipment or the like on a base by way of a driving shaft and positioning the table at a predetermined position. The stage apparatus comprises a guide mechanism for guiding and supporting the table on the base; a linear motor provided between the base and the table along a direction in which the table is fed; and controlling means for controlling, for a predetermined period before the table is stopped, stopping operations of the driving shaft and the linear motor in a mutually associated relationship in accordance with predetermined controlling conditions.

Abstract: An actuator positioned in accordance with two signals, the first being predominant and having a noise portion of magnitude which would mask the second signal and wherein the first signal is filtered to remove the noise and is connected to the actuator independently of the second signal so that the resultant motion of the actuator is additive of the two signals.

Abstract: A linear motor path forms a closed figure. Contactless power control and position feedback permit a linear motor stage to traverse the closed figure without interference from trailing wires. One embodiment of the closed figure includes a racetrack pattern with straight runs joined by curved ends. Axes of armature windings are skewed to lie across the path in the curved ends to maintain force on the linear motor stage. Other embodiments of the invention includes multilevel paths wherein one portion of the path crosses over another portion of the path. Disclosure is made of a linear motor stage supported below the path by magnetic attraction between permanent magnets on the stage and magnetic material in the path.

Abstract: An intriguing and educational display structure (2) includes a translucent earth globe body (3) suspended by energy derived from solar cells (14) integral to the globe. The globe is suspended by magnetic forces between magnets within the support assembly (10) which is controlled by a servo system substantially integral to the globe and powered by the solar cells (14). The servo mechanism can be made to launch and land the suspended globe in response to changing levels of illumination. Energy can be stored within the globe to power occasional periods of suspension, even in very low light levels.

Abstract: A drive system for transferring a work load suspended from a hoist from one work processing stage to another in a series of stages. Included in the system is an X-linear motor which causes the hoist to travel along a horizontal path running from stage to stage, and a Y-linear motor causing the hoist, when at a selected stage, to travel in a vertical path to lower the work load into the stage for processing and then raise the load so that it can travel to another stage. Power for the X-motor is supplied by an external source, but power for the Y-motor which is electromagnetically coupled to the X-motor is inductively derived from the X-motor, thereby obviating the need for a power cable for the Y-motor.

Abstract: An exposure apparatus optically transfers a pattern drawn on an original plate onto an exposure target. When positioning a stage, which is movable with an exposure target or original plate being mounted thereon, the coordinate origin as the reference is switched, when necessary, to match the operating state of the apparatus. The stage is positioned with reference to coordinate information having this coordinate origin as the reference.

Abstract: A magnetic power apparatus includes an outer shell made of magnetically conductive metal, the outer shell having a through hole on one side wall thereof, an iron core axially movably disposed inside the outer shell, a coil positioned in the outer shell around the iron core and controlled to move the iron core axially in the outer shell, a first permanent magnet and a second permanent magnet symmetrically mounted inside the outer shell and axially aligned at two opposite sides of the iron core with same pole aimed against each other, and a driving circuit disposed outside the outer shell and connected with a power output line thereof to the coil to charge a capacitor, the driving circuit outputting to the coil a positive impulse voltage when electrically connected, or a negative impulse voltage when electrically disconnected, causing the iron core to shift the iron core, and causing the first permanent magnet and the second permanent magnet to change magnetic path and to keep the iron core in shifted position.

Abstract: A system for controlling the movement of a movable member with respect to a stationary member, such as is found in a vibration welding apparatus. The system may include a force controller that converts desired force command signals into desired flux command signals and a flux controller that controls the flux in a magnetic core of the stationary assembly to effect the desired movement of the movable member. The stationary assembly may include a plurality of magnetically uncoupled E-cores of paramagnetic material.

Abstract: A vector controlled system for two AC induction linear motors to effect dual axis planar motion. There are two or four motors located in a shuttle element. The element is mounted on a smooth face, which includes a glass surface on which the shuttle moves on an air bearing. Vector control for each of the motors accurately controls motor operation in a single axis. Accurate control of a shuttle is obtained in the orthogonal movement under the action of the motors which are respectively arranged for relatively orthogonal movement. Feedback means between the motors and linear scales formed in the backiron associated with the glass face facilitates the controlled positioning of the motors and the shuttle element on the glass face.

Abstract: A media ejection system includes a peripheral unit having a housing, an ejection mechanism, and a memory wire coupled to the ejection mechanism. The system further includes a digital processor for issuing ejection commands, and a controller responsive to the ejection command for controlling a current flow through the memory wire. When sufficient current flows through the memory wire, it contracts to activate the ejection mechanism, thereby ejecting a removable medium (such a PCMCIA card) from the housing of the peripheral unit. A method of the invention includes the steps of receiving an ejection request, issuing a ejection command in response to the ejection request, where the ejection command includes parameters for controlling current flow through the metal alloy, and electrically energizing the memory alloy in accordance with the parameters such that the memory alloy undergoes a dimensional change to activate a removable medium ejection mechanism.

Abstract: The modular conveyor system comprises N interconnected track sections, forming a continuous track, wherein each track section features a plurality of individually controlled coils stretching along the length thereof. Plural pallets, each having thrust producing magnets, travel independently alone the track. The track also comprises multiple linear encoder readers spaced at fixed positions therealong, and each pallet includes a linear encoder strip having a length R greater than the spacing E between the readers. Track section controllers associate the encoder strips with only one reader at any time in order to resolve the position of the pallets based on the fixed position of the readers and the relative positions of the strips in relation thereto. The section controllers also regulate and commutate the coils of the corresponding track sections in order to independently control each pallet. Communication links interface adjacent section controllers situated in adjacent track sections.

Abstract: An adaptive, discrete-time sliding mode controller (SMC) is disclosed which detects and adapts to gain variations in the controlled plant. The overall control effort is generated by combining a linear control effort with a discrete-time sliding mode control effort generated by switching between gains in order to drive the system's phase states toward a sliding line trajectory. A sliding mode variable &sgr;k defines the position of the system phase states relative to the sliding line. The SMC controller is designed such that the sliding mode variable &sgr;k crosses the sliding line and changes sign at every sample interval. For the nominal plant gain, the SMC controller is also designed such that the magnitude of the sliding mode variable &sgr;k+1=−&sgr;k will remain constant (&sgr;k+1=−&sgr;k) and substantially constrained to |&sgr;k|=&Dgr;/(1+&lgr;) where &Dgr; and &lgr; are predetermined design constants.

Abstract: The invention discloses a closed loop planar linear motor which includes a stationary stator (or platen) of arbitrary extent, and a moving forcer which is a single rigid body that can move over the planar stator surface on an air bearing with high speed and high precision in two orthogonal translational directions and a small rotation (or combinations thereof). An important distinguishing feature is a monolithic position and orientation sensor based on alternating current (AC) magnetic techniques which is an integral part of the forcer and occupies otherwise unused space in the forcer body. Also incorporated within the forcer is a special electronic processing element which converts weak AC signals from the sensor into usable high precision position and orientation information relative to the stator surface.

Abstract: The invention comprises a platform positionable in at least three degrees of freedom at least partly by interaction with coils. The platform includes a support member having a surface. Magnets are attached to the surface and part of a magnet bearing is attached to the support member. Inner and outer platforms are coupled to each other by magnet bearings and interact with coils to position the inner platform in six degrees of freedom. The invention may be particularly useful in precise positioning of semiconductor wafers and materials during photolithography and other processing.

Abstract: A system is disclosed for correcting for rotational errors in a linear motor system. A shunt resistor is coupled in parallel with a winding of a phase of a motor of the linear motor system to correct for rotational errors caused by differences in the magnetic characteristics of the motors comprising the linear motor system. Yaw error values for the motors are sequentially measured to determine the value of the shunt resistor, and its location on a winding of a phase motor of the linear motor system.

Abstract: The invention relates to control device and control process for motors. In order to prevent phase distortion and the like in controlled systems, a sensor (250) for detecting the state of movement of a motor (200) is provided directly on or in the force transmission interface (270) of the motor. The sensor can, for example, determine the position, speed or acceleration directly. The invention is particularly suitable for controlling linear motors in high-precision applications, such as machine tools, milling machines or pick-and-place robots.

Abstract: Circuits for converting DC voltage into controllably variable amplitude AC voltage, for the purpose of driving an oscillating linear motor with controllable amplitude, are disclosed. Unlike pulse width modulation circuits for the same purpose, the disclosed circuits do not require suppression of electromagnetic interference and have negligible switching loss.

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.