Abstract: A method including the following steps: clamping and centering a toothing on a measuring spindle of a coordinate measuring machine; and measuring a geometry of a toothing using an optical measuring system of the coordinate measuring machine. The toothing is rotated during the measurement by a rotation of the measuring spindle. A rotational speed of the measuring spindle is adjusted and/or increased or decreased depending on a tolerance class of the toothing to be measured.

Abstract: An output of an eddy current sensor includes an impedance component. A film thickness measuring apparatus obtains film thickness information from the impedance component. Using a non-linear function between the film thickness information and the film thickness, the film thickness is obtained from the film thickness information. When a resistance component and a reactance component of the impedance component are associated with respective axes of a coordinate system having two orthogonal coordinate axes, the film thickness information is a reciprocal of a tangent of an impedance angle which is an angle formed by a straight line connecting a point on the coordinate system corresponding to the impedance component and a predetermined reference point, and a predetermined straight line.

Abstract: A method of detecting abnormality of a roller which transmits a local load to a retainer ring is disclosed.

Abstract: A method of ordering a new optical article definable based on features of an initial optical article including at least a lens, the method including the following steps: —acquiring an identifier by capturing a marking carried by the lens of the initial optical article; —sending, by an electronic device, the identifier and an order for the new optical article. A corresponding apparatus and a corresponding method for launching production of the new optical article are also described.

Abstract: In a spherical lens surface processing method, a lens surface is ground to a spherical surface by forming a contact state in which a rotating cup-shaped grinding stone is placed in contact with the lens surface and a sphere center oscillation state in which the cup-shaped grinding stone oscillates along the lens surface centered on a sphere center. In the sphere center oscillation state, the distance from the center of the sphere center oscillation to the contact point of the cup-shaped grinding stone with the lens surface is set to be the same as the radius of the spherical surface. The oscillation width of the sphere center oscillation is set so that the contact point of the cup-shaped grinding store with the lens surface can move from one peripheral edge of the lens surface past the lens center on the lens surface to the other peripheral edge.

Abstract: To provide a reference temperature setting device, a reference temperature setting method, and a reference temperature setting program capable of setting an appropriate reference temperature for thermal displacement compensation. A reference temperature setting device comprises: an acquisition unit that acquires measured values from multiple temperature sensors installed on a machine; and a determination unit that determines setting timing for a reference temperature for thermal displacement compensation to coincide with a point in time when the measured values satisfy a predetermined condition.

Abstract: Processing device for uniformly grinding wafers held by a plurality of chucks, and a method for setting the processing device. A processing device includes a coarse grinding device and a fine grinding device that are provided in a column straddling over a holding device. The holding device includes: an index table; chucks concentrically disposed about a rotation shaft; a first movable support unit on the outer peripheral side of the chuck in the radial direction of the index table; and a first fixed support unit on the inner peripheral side of the chuck in the radial direction of the index table. The first movable support unit is interposed between the index table and the chuck, and can be freely expanded and contracted in a vertical direction.

Abstract: A polishing apparatus includes an acoustic sensor, a sound collector, an analyzer, a feature quantity calculator, and an end point calculator. The acoustic sensor detects the polishing sound of an object. The sound collector collects a polishing sound detected by the acoustic sensor. The analyzer performs frequency analysis on the power spectrum of the polishing sound with a predetermined time resolution. The feature quantity calculator calculates an arithmetic value of the power spectra having a preset time difference of the power spectra as a polishing feature quantity by using the analysis data provided by the analysis performed by the analyzer. The end point calculator determines a polishing end point of the object based on the change in the feature quantity.

Abstract: A piece of equipment that needs services may not have connectivity to a network. In an example method, an event triggers the piece of equipment to generate a barcode or QR code. The event may be installation of equipment, preventive maintenance, update of software, periodic calibration, abnormal operation, change of location, etc. The barcode or QR code contains information of the piece of equipment and the triggering event. The piece of equipment halts upon display of the barcode or QR code. An application installed in a user device scans the barcode or QR code and sends a message to a remote service center. The service center analyzes the message and updates a service database. The service center returns a key in a message back to the user device. When the key is input into the piece of equipment, the operation of the piece of equipment is resumed.

Abstract: Embodiments described herein relate to methods of detecting a polishing endpoint using one or more sensors embedded in the polishing material of a polishing pad, the polishing pads, and methods of forming the polishing pads. In one embodiment, a method of polishing a substrate includes urging a to be polished surface of a substrate against a polishing surface of a polishing pad, the polishing pad having one or more sensors embedded in the polishing pad material thereof, wherein the polishing pad is mounted on a polishing platen of a polishing system, detecting a force exerted against a polishing surface of the polishing pad using the one or more sensors, converting the detected force into signal information, wirelessly communicating the signal information received from the one or more sensors to one or more interrogators disposed in the polishing platen, and changing one or more polishing conditions based on the signal information.

Abstract: An integrated equipment for processing a plurality of fiber optic ferrules comprises a polishing system, a ferrule cleaning system, a drying system, a wiping system, and a robot system. The polishing system polishes a plurality of front end faces of the plurality of fiber optic ferrules mounted on a carrier. The ferrule cleaning system cleans the carrier and the fiber optic ferrules on the carrier after the fiber optic ferrules have been polished. The drying system dries the carrier and the fiber optic ferrules on the carrier after the carrier and the fiber optic ferrules have been cleaned. The wiping system wipes the front end faces of the fiber optic ferrules on the carrier after the carrier and the fiber optic ferrules have been dried. The robot system transfers the carrier to the polishing system, the ferrule cleaning system, the drying system, and the wiping system.

Abstract: A device for adjusting the setting of and/or for measuring a tool includes a measuring element carrier which can move along a first axis (x-axis), and along a second axis (z-axis) that extends at right angles to the first axis, on which measuring element carrier a measuring element for the optical measurement of the tool is disposed. To facilitate the adjusting and measuring process, a reference body, which is able to move between a standby position and a measuring position on the tool, is disposed on the measuring element carrier for interaction with the measuring element.

Abstract: A rod slicer includes a receiving vessel, a cover vessel, and a rod mount. The rod mount may releasably couple with the cover vessel. At least one blade is mounted to or within the cover vessel. The rod mount has openings for one or more rods. The rod mount can be rotated, causing any rods in the openings to pass across from the rod mount into the cover vessel. In the cover vessel, a slicing edge of the blade, thus cutting a segment of a desired length from the rod. A pump may be connected to an opening in the vessel to vacuum the cut segments into the vessel. In some configurations, the blade is adjustable to change the length of the segments.

Abstract: An apparatus, system, and method using an elastic biasing element in combination with an encoder arrangement for precise control of force or torque applied to a moving object, is applied for controlling a feed force applied to an abrasive element of a bore finishing tool, to respond to changes in the feed force such as can arise from contact with a workpiece bore surface and variations therein, such as tapers, hourglass shapes, barrel shapes, and the like. The elastic biasing element can include a single or multiple springs in one or more sets, and the feed force can be selected to have a constant value or vary as a function of time, position, or other variables or conditions.

Abstract: An automated hand tool sharpening and cleaning system for sharpening the two opposed cutting edges of domestic, industrial, sport, or hobby hand tool like a knife blade is provided by the invention. The apparatus comprises a six-axis robotic arm, a pneumatic gripper, a vision sensor camera for profiling the blade edges, a robotic controller, and sequentially-arranged grinding, coarse sharpening, fine sharpening, and buffing rotating wheel assemblies used to grind, sharpen, and buff or polish the cutting edges of the knife blade. The blade cutting edges are profiled by the camera image that is processed by associated software to define the blade by multiple points defined along its edge, followed by a set of algorithms that are used to clean up any discrepancies in the profile data.

Abstract: A method for varying a removal profile of a silicon wafer during polishing using a polishing apparatus is provided. The polishing apparatus includes a polishing pad, a polishing head assembly configured to hold the silicon wafer, a temperature sensor, and a controller. The method includes receiving, at the controller, thermal data of a portion of the polishing pad from the temperature sensor and determining, by the controller, the removal profile of the silicon wafer based at least in part on the thermal data. The method further includes operating, by the controller, the polishing head assembly to position the silicon wafer in contact with the polishing pad and to selectively vary the removal profile of the silicon wafer based at least in part on the thermal data.

Abstract: A machine and method for the finishing of gears with a finishing tool, in particular a grinding wheel; the machine having a plurality of workpiece carrier slides, a plurality of workpiece carrier spindles, each of which is mounted on a respective workpiece carrier slide, and a plurality of loading-unloading stations; each workpiece carrier spindle is rotating and supports a gear; each workpiece carrier slide slides from a respective loading-unloading station to a working station and vice versa; in which the control unit synchronizes the rotation of each gear with the rotation of the finishing tool outside of the working station so that by entering the working station the gear meshes with the finishing tool without collisions.

Abstract: Disclosed is a reversing machine that reverses a substrate upside down. The reversing machine includes: a first arm pair configured to mount a substrate thereon; a second arm pair facing the first arm pair; an opening/closing mechanism configured to open/close the second arm pair so as to grip the substrate mounted on the first arm pair; and a rotating mechanism configured to rotate the first arm pair and the second arm pair around a predetermined axis that is set inside the first arm pair and the second arm pair and extends along an extension direction of the first arm pair and the second arm pair such that the substrate is reversed upside down.

Abstract: Collecting data includes generating a sensor signal from each of a plurality of sensors located on a sensing roll, wherein each signal is generated when each sensor enters a region of a nip between the sensing roll and mating roll during each rotation of the sensing roll; wherein a web of material travels through the nip and a continuous band contacts a region of the web of material upstream from or at the nip. A periodically occurring starting reference is generated associated with each rotation of the continuous band and the signal generated by each sensor is received so that the one of the plurality of sensors which generated this signal is determined and one of a plurality of tracking segments associated with the continuous band is identified. The signal is stored to associate the respective sensor signal with the identified one tracking segment.

Abstract: A method for fabricating an integrated circuit includes providing a partitioned chemical-mechanical planarization (CMP) model having a plurality of model parameters that include (i) device specific model parameters and (ii) at least one common parameter. (i) include a pre-CMP thickness of a film including a first material on an in-process device, a post-CMP target thickness for the film on the in-process device, and device group properties that account for device structure for the in-process device. (ii) includes a polish rate from an unpatterned pilot wafer having a second material thereon. The second material need not be the same as the first material. The polish time is automatically determined using the partitioned CMP model. A CMP process is performed on a patterned product wafer having a plurality of the in-process devices using a recipe including the polish time.

Abstract: The invention relates to a method (100) for orientation of a workpiece (20) to be processed, comprising the steps of: a) providing a processing path (27) fixed on the workpiece for processing the workpiece (20); b) selecting a rigid transformation (30) of the positioning of the workpiece (20); c) simulating the processing path (27) taking account of the rigid transformation (30) of the positioning of the workpiece (20); d) determining at least one process variable (40) of the machining of the workpiece (20); wherein the steps b) to d) are repeated by modifying the at least one rigid transformation (30) of the positioning of the workpiece (20) until the at least one process variable (40) reaches a target value (43).

Abstract: A continuous-generation gear grinding method of conducting a gear grinding process such that while a thread-shaped grinding wheel is rotated around an axial center thereof and fed in an axial center direction, a position coming into contact with abrasive grains is constantly changed in the presence of a water-soluble grinding fluid by performing a grinding feed in a direction parallel to an axial center of a gear blank and by serially rotating the gear blank around the axial center, the grinding wheel being a vitrified grinding wheel having abrasive grains bonded by a vitrified bond with pores formed among the abrasive grains, and the abrasive grains having a grain size of F120 to F180.

Abstract: Described are systems and methods for controlling an ophthalmic lens edging machine are disclosed. The ophthalmic lens edging machine uses an edger code to select a macro or speed for a requested lens edging job. A system for creating and using the edger code may include a Lab Management System (LMS), a lens calculation system, and a lens edging machine. An edger code may be generated using lens data received from a lens management system and edging machine information identifying lens edging machines. The edger code comprises a plurality of characters. Each character is associated with a different feature of a requested edging job. The features of the requested edging job may include, for example, one or more of: a material type, a lens thickness, an edge type, a frame type, a lens coating, a lens shape, a lens ratio, a lens treatment, and an edging machine block type.

Abstract: Disclosed herein are an apparatus and method for controlling the capture of an image of a cut surface. The apparatus for controlling the capture of an image of the cut surface of material that is cut using a cutting device includes a signal generation unit for outputting a signal, a sensor unit for sensing the output signal using multiple sensors and generating a sensing signal, and an image capture control unit for controlling an image-capturing operation of an imaging device, which captures the image of the cut surface, using the sensing signal.

Abstract: A workpiece processing apparatus including: a center drum that is rotatable around a rotation axis and has at least one first groove formed in the axial direction on the peripheral surface, a carrier having a holding hole to insert and hold a workpiece to be processed, an upper and lower turn table that are rotatable around the rotation axis in a state wherein the carrier holding workpiece is interposed, at least one hook fitted in the upper turn table's internal circumference, with the tip being inserted into the first groove and movable along first groove; wherein the center drum has at least one second groove formed in the axial direction on peripheral surface, and second groove has a length different from that of the first groove and has a supporting surface to support the hook from below at a position above a position where upper turn table processes the workpiece.

Abstract: In a scroll machining method, a scroll has a disc-like end plate and a scroll wall extending from a first side surface of the disc-like end plate, and the scroll is driven to rotate around a center axis C of the scroll, and a first cutter machines a side wall surface of the scroll wall while the scroll is rotating. The first cutter is a non-rotary cutter. When the scroll is machined, the scroll rotates around its center axis, and the first cutter does not rotate around its axis, thereby improving the scroll's machining precision and machining efficiency.

Abstract: A detection system include a light source including three or more than three equiangularly spaced light-emitting devices for emitting light onto multiple cutting edges of a cutter blade of a cutter, a camera for capturing images of the cutting blade of the cutter, and a controller electrically coupled with the light source and the camera and capable of figuring out the angle of the cutter blade of the cutter by analyzing the images of the cutter blade and then controlling one specific light-emitting device to emit light onto the cutter blade of the cutter.

Abstract: A machining apparatus for a workpieces includes an upper turn table support mechanism supporting an upper turn table from above to be vertically movable by a cylinder extending along a rotational axis direction of the table, a horizontal plate fixed to the cylinder so that a main surface thereof becomes perpendicular to a longitudinal axis of the cylinder, at least three displacement sensors which measure horizontal plate surface height positions when the upper turn table has moved down to a fixed position, and a control apparatus to calculate a relative upper turn table height position and an angle formed between the upper turn table rotational axis and the cylinder longitudinal axis from the horizontal plate surface height positions measured by the displacement sensors. A workpiece holding abnormality can be accurately and quickly detected before machining the workpiece to avoid damage, and an cylinder eccentric angle can be detected during machining.

Abstract: An embodiment relates to a wafer loading apparatus of wafer polishing equipment.

Abstract: The present invention provides methods for chemical mechanical polishing (CMP polishing) spin coated organic polymer films on a semiconductor wafer or substrate as part of lithography or as part of electronic packaging. The methods comprising spin coating an organic polymer liquid on a semiconductor wafer or substrate; at least partially curing the spin coating to form an organic polymer film; and, CMP polishing the organic polymer film with a polishing pad and an aqueous CMP polishing composition having a pH ranging from 1.5 to 4.5 and comprising elongated, bent or nodular silica particles containing one or more cationic nitrogen or phosphorus atoms, from 0.005 to 0.5 wt. %, based on total CMP polishing composition solids, of a sulfate group containing C8 to C18 alkyl or alkenyl group surfactant, and a pH adjusting agent.

Abstract: A plating apparatus allows a substrate holder to be serviced easily while ensuring easy access to the substrate holder and while a substrate is being processed in the plating apparatus. The plating apparatus includes a plating section for plating a substrate, a substrate holder for holding the substrate, a substrate holder transporter for holding and transporting the substrate holder, a stocker for storing the substrate holder, and a stocker setting section for storing the stocker therein. The stocker includes a moving mechanism for moving the stocker into and out of the stocker setting section.

Abstract: A surface measurement device includes a rotating platform, a motion lever, a measuring module and a control module. The rotating platform rotates an object at a rotating speed. The motion lever is above the rotating platform. The measuring module moves to a variety of measuring positions on the motion lever. When the measuring module is at one of the measuring positions, the measuring module measures the heights of a plurality of sampling points on the surface of the object in a sampling frequency. The control module selectively modifies the rotating speed of the rotating platform or the sampling frequency of the measuring module according to the measuring position of the measuring module to make the distance between the sampling points in at least a region of the surface of the object match a sampling rule.

Abstract: A lens processing management system includes a lens processing section that processes a lens based on design data, an authentication section that is substantially attached to a lens material or a semi-finished lens product, and an authentication processing section that performs an authentication process for the processing of the lens using the authentication section.

Abstract: A method and system simulates a work process on a machine tool using a virtual machine. The virtual machine is set up to simulate the work process on the machine tool using machine data, workpiece data, and tool data as a function of numerical control (NC) control data and programmable logic control (PLC) control data. The work process is simulated on a platform that comprises a plurality of processor cores, wherein the work process is simulated in partial simulations that run in parallel on different processor cores.

Abstract: A surface measuring device includes a rotary platform, a shifting lever, a measuring module, and a control module. The rotary platform carries an object under test and rotates the object under test at a rotating speed. The shifting lever is above the rotary platform. The measuring module disposed on the shifting lever moves to measurement positions on the shifting lever and performs a surface height measurement at a sampling frequency to sampling points on a surface of the object under test when located at one measurement position. The control module selectively adjusts the rotational speed for the rotary platform or the sampling frequency for the measuring module according to the measurement position of the measuring module on the shifting lever in order to fit a distance between the sampling points on at least one part of the surface of the object under test to a sampling rule.

Abstract: A polishing apparatus includes a platen having a first surface to support a polishing pad and a second surface, a carrier head to hold a substrate against the polishing pad, a plurality of through-holes defined in the platen, and a pad pressure control assembly adjacent on a side of the platen opposite the carrier head.

Abstract: A polishing method of polishing a substrate includes moving a stopper from a predetermined initial position by a distance corresponding to a target polishing amount of a substrate. The method further includes pressing a polishing tool against the substrate by a pressing member while rotating the substrate. The method further includes polishing the substrate until a positioning member which moves together with the pressing member is brought into contact with the stopper.

Abstract: The present disclosure relates to a technical field of manufacturing a display device, and more particular to a method and a device for controlling a grinding of a flexible substrate. The method includes: grinding an etching side of the flexible substrate; irradiating the flexible substrate with infrared rays or near infrared rays, receiving waves reflected by a side opposite to the grinding side and waves reflected by the grinding side of the flexible substrate respectively, and calculating a distance between the two sides based on the reflected waves; comparing the distance with a predetermined thickness of the flexible substrate in real time, and controlling an extent of grinding by a grinding device based on a difference of the distance from the grinding side to the side opposite to the grinding side of the flexible substrate and the predetermined thickness of the flexible substrate.

Abstract: Polishing systems and methods for polishing a substrate are provided. The polishing system includes a polishing assembly having a platen and a polishing pad over the platen. The polishing system also includes a substrate carrying assembly configured to engage a substrate to the polishing pad. The polishing system further includes a thickness sensing assembly configured to monitor a thickness of the polishing pad.

Abstract: An apparatus for positioning a geometric model comprises a machine tool, a control unit electrically coupled to the machine tool, a storage unit electrically coupled to the control unit, a positioning module electrically coupled to the storage unit, a virtual target geometry module electrically coupled to the positioning module, and a virtual machine tool module electrically and respectively coupled to the virtual target geometry module and the positioning module. A method for positioning the geometric model includes using components of the apparatus.

Abstract: There is provided a polishing apparatus capable of detecting uneven wear occurring on a polishing pad and detecting an appropriate replacement timing of the polishing pad. The polishing apparatus detects, every predetermined time, a value of rotation speed or a value of rotation torque of a table drive shaft for rotationally driving a polishing table or a dresser drive shaft for driving a dresser, or a value of swing torque of a dresser swing shaft for driving the dresser; calculates a change quantity thereof based on the value of the detected rotation speed, the value of the detected rotation torque, or the value of the detected swing torque; determines whether or not the change quantity exceeds a predetermined value; and notifies a user of a warning when a determination is made that the change quantity exceeds the predetermined value.

Abstract: A planarization method is provided. The planarization method includes providing a wafer, in which the wafer includes a work function layer, a surface layer formed on the work function layer and oxidized from the work function layer, and a planarization layer disposed on or above the surface layer, performing a chemical-mechanical planarization (CMP) process on the planarization layer, providing an incident light to a surface of the wafer under the CMP process, detecting absorption of the incident light by the surface layer; and stopping the CMP process in response to an increase in the detected absorption of the incident light.

Abstract: A polishing apparatus capable of monitoring an accurate progress of polishing is disclosed. The polishing apparatus includes: a polishing table for supporting a polishing pad; a table motor configured to rotate the polishing table; a top ring configured to press a substrate against the polishing pad to polish the substrate; a dresser configured to dress the polishing pad while oscillating on the polishing pad during polishing of the substrate; a filtering device configured to remove a vibration component, having a frequency corresponding to an oscillation period of the dresser, from an output current signal of the table motor; and a polishing monitoring device configured to monitor a progress of polishing of the substrate based on the output current signal from which the vibration component has been removed.

Abstract: A method of controlling a polishing operation includes receiving a first measurement of a first amount of metal on a substrate made by a first x-ray monitoring system after a first metal layer is deposited on the substrate and before a second metal layer is deposited on the substrate, transferring the substrate to a carrier head of a chemical mechanical polishing apparatus the substrate after the second metal layer is deposited on the substrate, making a second measurement of a second amount of metal on the substrate with a second x-ray monitoring system in the chemical mechanical polishing apparatus, comparing the first measurement to the second measurement to determine a difference, and adjusting a polishing endpoint or a polishing parameter of the polishing apparatus based on the difference.

Abstract: A load cup apparatus for transferring a substrate in a processing system includes a pedestal assembly having a substrate support, an actuator, and a controller. The actuator is configured to move the pedestal assembly into a loading position in contact with a retaining ring of a carrier head and to generate a retaining ring thickness signal based on a distance travelled by the pedestal assembly. The controller is configured to receive the retaining ring thickness signal from the actuator.

Abstract: Systems and methods are provided for use in processing and/or grinding wafers or other work products. Some embodiments provide a grinding apparatus that comprise a base casting; a rotary indexer configured to rotate within the base casting; a work spindle secured with the rotary indexer; a work chuck coupled with the first work spindle, wherein the first work spindle is configured to rotate the first work chuck; a bridge casting secured relative to the base casting, wherein the bridge casting bridges across at least a portion of the rotary indexer and is supported structurally forming a closed stiffness loop; a grind spindle secured with the bridge casting; and a grind wheel cooperated with the grind spindle, wherein the bridge casting secures the grind spindle.

Abstract: The invention relates to an ophthalmic machining machine comprising machining means and means for supporting a blank. The invention is characterized in that the machine is capable of transferring marks to said blank that can be identified by monitoring means for repositioning the blank on said supporting means after machining the opposite surface. The invention also relates to a workholding tool. The invention is characterized in that said supporting means are mounted on a bearing surface, which is oblique in relation to a surface of a carriage, by depression of an opening surrounded by an O-ring seal and a fixed bearing. The invention also relates to a machining method according to which the markings are transferred to a blank, the position of said markings is assessed by monitoring means which position machining means for the machining process, and each surface of the resulting lens is polished with polishing means.

Abstract: A device and a method for processing an optical lens are proposed, whereby lens-production data and/or geometric data of the lens are determined from desired optical data of the lens when a corresponding activation code is acquired. Preferably, the lens or a block piece and/or an assigned shipping container is/are provided with the activation code and/or other information relative to the lenses that are to be processed.

Abstract: A truing device of a grinding machine includes: a truer that corrects a shape of a grinding wheel; a swivel table that supports the truer such that the truer is swivelable about a swivel axis Ac; detecting means for directly detecting a distance from a truing edge position of the truer, which contacts the grinding wheel during correction of the shape of the grinding wheel, to a swivel center O of the swivel table; and control means for controlling the truing edge position of the truer with respect to the grinding wheel based on the distance L detected by the detecting means to true the grinding wheel.

Abstract: A machine tool 1 comprises a bed 11, a column 12, a spindle head 15, a spindle 16, a saddle 17, a table 18, a feed mechanism for moving the spindle head 15, the saddle 17 and the table 18 in Z-axis, Y-axis and X-axis directions respectively, a position detector for detecting the positions of the spindle head 15, saddle 17 and table 18, a controller for feedback controlling the feed mechanism, a position detector 51 for detecting the position of the spindle head 15, a position detector 54 for detecting the position of the spindle head 15, a position detector 57 for detecting the position of the table 18, and a measurement frame 50 which is configured with a different member from the bed 11 and the column 12 and on which readers 53, 56, 59 of the position detectors 51, 54, 57 are disposed.