Abstract: A head slider having an air inlet end and an air outlet end includes a rail having a flat air bearing surface for generating floating force when the disk rotates, the rail being disposed on a disk-facing surface; and an electromagnetic transducer disposed near the air outlet end where the rail is positioned. The head slider has a cavity on the air outlet end near the electromagnetic transducer.

Abstract: An apparatus and method for grinding a workpiece by rotating the workpiece about a rotational axis, rotating a cylindrical grinding wheel about a rotational axis being parallel to the rotational axis of the workpiece, moving the grinding wheel relative to the workpiece at least in one of a first direction being perpendicular to the rotational axis of the workpiece for grinding the workpiece at a cylindrical surface of the grinding wheel and a second direction being parallel to the rotational axis of the workpiece for grinding the workpiece at an end surface of the grinding wheel being perpendicular to the rotational axis of the grinding wheel, and by superimposing a vibration signal including a plurality of frequency components to a driving signal outputted to one of a workpiece rotating means for rotating the workpiece and a grinding wheel rotating means for rotating the grinding wheel.

Abstract: An eyeglass lens processing system includes a main processing apparatus having a first lens chuck, a roughing tool, a first bevel-finishing tool, a lens edge measuring unit, and a first computing unit to obtain roughing data and first bevel-finishing data, and a sub processing apparatus, and having a second lens chuck, and a second bevel-finishing tool having a smaller diameter than the first bevel-finishing tool. The main processing apparatus has a means to set whether processing of the lens is performed by the first and second bevel-finishing tools, a transmission unit that transmits at least one of second bevel-finishing data or data for obtaining the second bevel-finishing data to the sub processing apparatus, a first control unit that performs roughing based on the roughing data and bevel-finishing based on the first bevel-finishing data. The sub processing unit has a second control unit that performs bevel-finishing based on the second bevel-finishing data.

Abstract: A method and apparatus for cutting a profile in a workpiece, such as a turbine disk, without cracking the parent material which includes providing a grinding wheel having a ceramic grinding surface formed with an optimized grain material and grain spacing to produce large chips that are easily removed from the workpiece, applying the grinding wheel to the workpiece at a predetermined material removal rate, and increasing the material removal rate when the burning point is recognized at the surface of the workpiece by the grinding action of the grinding wheel, and delivering coolant/lubricant to the workpiece during the grinding operation.

Abstract: An apparatus (1) for smoothing a product (2), in particular a semi-finished ceramic product, comprises: an abrasive tool (3) in the form of an endless belt (4) which is trained around at least one pair of pulleys (5, 6), at least one of which is power-driven; the belt (4) has an active section (7) and at least one passive section (8); the active section (7) removes material from the product (2), while the passive section (8) receives a regenerating treatment that restores the abrasive capacity of the tool (3); drive means (20) acting on the belt (4) in such a way as to enable the belt (4) itself to move in the space surrounding the product (2); means (10) for spraying a liquid on the belt (4), which has liquid absorption properties, said means (10) being located in the vicinity of the belt (4) itself; and negative pressure means (9) associated with the passive section (8) of the belt (4) and operating in such a way as to extract the liquid and the materials retained by the belt (4) and removed from the produc

Abstract: A platen assembly is provided for supporting a polish pad of the type utilized to planarize a wafer. The platen assembly comprises a sensor system and a polish platen having a first surface for supporting the polish pad. The sensor system comprises a flexible sensor and a flexible circuit operatively coupled to the sensor controller. The flexible circuit includes a first flexible sensor disposed proximate the first surface.

Abstract: A method for providing a surface structure wherein conventional grinding micro scratches are broken up to provide a diffuse structure of micro scratches and micro flats resulting from grinding wheel motion comprising an eccentric revolving of the grinding wheel and/or grinding wheel pulsing.

Abstract: A grinding and polishing machine, in particular for lenses, has at least one tool spindle and at least one workpiece. The tool spindle is constructed to hold a respective tool on the same axis at both ends and is mounted in a spindle housing which can be pivoted about a pivot axis arranged at right angles to the tool spindle in order to provide in each case one tool for machining engagement and also at various defined angle positions with respect to the workpiece spindle. A drive arranged on the pivot axis pivotably moves the tool spindle about the pivot axis for the desired machining engagement and rotates the tool about the pivot axis into the various angle positions with respect to the workpiece.

Abstract: A water jet-processing machine comprising a workpiece holding table having a holding surface for holding a workpiece, a nozzle for emitting a jet of processing water to the workpiece held on the holding surface of the workpiece holding table, a processing water supply means for supplying processing water containing abrasive grains to the nozzle and a moving means for moving the nozzle in a direction perpendicular to the holding surface of the workpiece holding table, wherein the machine further comprises processing sound wave detection means for detecting a processing sound wave generated by processing water ejected from the nozzle to the workpiece and a control means for controlling the moving means based on a detection signal detected by the processing sound wave detection means.

Abstract: A method of transferring a wafer is disclosed. The method comprises providing a pedestal and at least one spray orifice extending through the pedestal; disposing a wafer above the pedestal using a first robot, wherein the wafer has a first surface and a second surface, the first surface faces the pedestal, a fluid is sprayed onto the first surface simultaneously to avoid a contact of the first surface with the pedestal, and the fluid contains a charge-forming chemical substance dissolved therein; and taking the wafer using a robot for delivery. Due to the charge-forming chemical substance dissolved in the fluid, the waterfall effect to cause discharge damage on the wafer is avoided in the spraying of the fluid.

Abstract: A process for monitoring the correct setting of the coolant nozzle (9) of a grinding machine for grinding the tooth flanks of workpieces with premachined teeth. In an automatic test cycle after setting the machine, with the grinding wheel (2) at defined positions relative to the workpiece (3), the alterations in power consumption of the grinding spindle drive when switching on the coolant supply are measured, compared with the desired value ranges specified in the machine control system, and the machining process blocked in the event of measurements being below or above the desired value ranges. In this manner the production of scrap and the occurrence of deflagration of the coolant/lubricant-air mixture in the machine working area, and hence a machine fire, can be effectively prevented.

Abstract: A method of grinding the outer circumferential surface of a workpiece 5 formed of a hard and brittle material into a predetermined shape using a grinding wheel while rotating the workpiece 5 is disclosed. The method includes plunge grinding the workpiece 5 at an arbitrary portion (plunge ground portion 21) in the longitudinal direction of the workpiece 5 by causing the grinding wheel to come in contact with the workpiece 5 in a direction which intersects a rotational axis 8 of the workpiece 5, and traverse grinding the workpiece 5 toward the plunge ground portion 21 by moving the grinding wheel relative to the workpiece 5 in a direction parallel to the rotational axis 8 of the workpiece 5. This allows the outer circumferential surface of the workpiece made of a hard and brittle material, such as a honeycomb structure used for a DPF, to be ground into a predetermined shape in a short time, and prevents occurrence of chipping during grinding.

Abstract: Various forms of knife guides are provided for knife sharpeners to minimize damage to the knife blade. One of the forms of knife guides comprises non-contact optical arrangements which includes a light source, at least one light detector and an indicator that monitors and displays the intensity of light reflected from the blade surface.

Abstract: A grinding method wherein the correlation between the amount of inertial grinding occurring in performing spark-out by a grinding unit and the maximum load current in a motor of the grinding unit is grasped, and a correction value for the amount of inertial grinding corresponding to the maximum load current is preliminarily obtained. When the wafer thickness measured by a thickness measuring gauge has reached the sum of a desired value and the correction value (=the amount of inertial grinding) corresponding to the maximum load current, the spark-out is started. Accordingly, the wafer thickness becomes the desired value after the inertial grinding in performing the spark-out.

Abstract: A polishing pad, platen, method of monitoring, method of manufacturing, and method of detecting using a pseudo window area, where the pseudo window area has a thickness less than a thickness of a polishing layer and a thickness greater than zero.

Abstract: A belt sanding system comprising a segmented sanding block including a plurality of individually controllable segments and one or more sanding belt deflecting rollers, a plurality of sensing elements corresponding to the plurality of segments, and a device for interconnecting the plurality of sensing elements, interconnecting the plurality of sensing elements with the segmented sanding block, and effecting lateral movement of the plurality of sensing elements as the segmented sanding block is rotated to an oblique alignment relative to the feed direction.

Abstract: A lens layout block device comprising a seal feeding device that supplies an elastic seal to a seal sticking position (A5). The elastic seal is loaded in a tape loading part in the form of a seal tape covered by a mount and a protective sheet and wound in a roll shape and fed by driving a motor. The protective sheet is separated by a protective sheet separating mechanism. At the seal sticking position (A5), a sensor detects the leading edge of a positioning hole in the mount and stops the conveyance of the seal tape after the seal tape is fed from the detection position for a specified time. The stop position is determined as the reference sticking position of the elastic seal and a lens holder is pressed against the elastic seal from above. The mount is pulled down by the seal separating mechanism to separate the mount from the elastic seal.

Abstract: A method of machining gears or other toothed articles wherein the workpiece feed rate and/or the tool shifting is varied so as to produce an irregular surface pattern on tooth surfaces with a resulting reduction in mesh noise. The method is particularly applicable to grinding spur and/or helical gears with a grinding worm.

Abstract: A jig intended in use to hold a series of blanks of rod-like or wire-like form during machining, the jig having a body adapted to be mounted to a drive shaft for rotation of the body about an axis of rotation, the body having a perimeter which on rotation of the jig defines a rotation path, the perimeter being defined by a set of stations located around the rotation path, each station having a pair of opposed clamping surfaces, one side of the clamping surfaces being located at the rotation path, in use the clamping surfaces being intended to receive between themselves a set of said blanks, one end of said blanks being positioned to extend outwardly from the one side to extend beyond the rotation path. The clamping surfaces can have a cylindrical or polygonal shape and the blanks can be supported to extend in a direction transverse to the rotation path or parallel to the rotation path. A process and grinding system are also claimed.

Abstract: The present invention provides an initial position setting method of grinding wheels, before starting a grinding operation, in a vertical double disc surface grinding machine for surface grinding the upper and lower grinding surfaces of a work-piece simultaneously by rotation-driving a pair of grinding wheels by a grinding wheel rotation drive motor and moving the grinding wheels up and down by a grinding wheel vertical drive motor.

Abstract: An extremely precise computer controlled grinding machine having the capability to write its own computer programs for controlling the grinding machine to perform individual tasks, including both grinding and dressing to several millionths of an inch. A new device for dressing is included which is directly on the machine, alleviating the need for a separate dressing machine. The Windows-based computer program is easy to use, and includes numerous features for self-maintenance and reproducibility.

Abstract: The automated floor sander includes numerous devices and mechanisms to facilitate the task of the operator of the machine. The machine includes a variable speed drive mechanism, enabling the operator to select the desired travel speed over the surface in order to optimize results. Another feature is the automated sanding drum lifting and lowering mechanism, which automatically raises and lowers the drum if the travel speed of the machine respectively decreases or increases below or above a predetermined point. A manual mechanism for controlling drum height is also provided. Yet another feature is a novel mechanism for automatically centering the sanding belt on its tension roller, which mechanism greatly reduces wear and tear on the belt and friction in the system when the belt reaches one end of the tension roller. These mechanisms may be incorporated separately from one another or in combination in a single machine, as desired.

Abstract: In a platen assembly for a polishing apparatus, a platen supports a polishing belt that makes contact with an object during a polishing process, so that the platen provides a pressure on the polishing belt during the polishing process. A plurality of first bladders extends in a first direction on an entire surface of the platen and is spaced apart by a uniform distance, and the first bladders apply pressure to the polishing belt. A plurality of second bladders extends in the first direction on a middle portion of the surface of the platen between a central portion and a peripheral portion of the platen and is positioned between the first bladders, and the second bladders apply pressure to the polishing belt. The pressures of the bladders are individually controlled by pressure controllers. Various pressures are individually applied different portions of the polishing belt by the bladders.

Abstract: A control system for controlling processing of workpieces such as jewelry has gantry and gimbal units having x, y, z translational and x, y, z rotational degrees of freedom, the units carrying a gripper for holding a piece of jewelry. Drive motors are associated with each translational and rotational degree of freedom and an actuator operates the gripper. A controller is linked to the gantry and gimbal unit motors, the gripper unit actuator, and actuators associated with a series of work stations for carrying out processing operations such as lapping and grinding. The controller controls movement of the gripper unit from a start position to pick up a workpiece and move it along a programmed path between the processing stations, and controls operation of actuators at each processing station to process workpieces according to stored program instructions. A user input device provides optional operator control of the movement and processing for system training purposes.

Abstract: This method for manufacturing a surface-coated cutting insert includes clamping and holding a surface-coated cutting insert with a pair of rotary shafts which are rotatable around an axis, and jetting an abrasive fluid to the surface of the surface-coated cutting insert using at least one blasting gun while rotating the surface-coated cutting insert, thereby, conducting wet blasting.

Abstract: A grinding system for grinding feedstock includes a transport apparatus, a grinding apparatus, and a controller. The transport apparatus continuously transports feedstock of an arbitrarily long length at a desired feed rate, and the grinding apparatus grinds the feedstock transported by the transport apparatus. The controller controls a grinding position of the grinding apparatus and a longitudinal position of the feedstock during grinding to be coordinated with each other.

Abstract: The feed system for a honing machine provides a capability to dynamically correct in real time errors in bore size inferred arising from variations in feed force, and a method of operation of the same. The system allows a user to select between rate and force controlled honing modes, which provides one or more of the advantages of both modes. The system provides capabilities for automatic rapid automatic bore wall detection, compensation for elasticity of elements of the feed system and honing tool, and automatic tool protection. The system is automatically operable using feed force, feed rate and positional information for honing a work piece to one or more target parameters, such as one or more in-process sizes and a final size.

Abstract: In an apparatus on a carding machine for grinding a fibre processing clothing on a roller or a card flat, grinding equipment includes at least one grinding element and an infeed device serving to position the grinding element against the clothing. To permit reliable detection and monitoring of the contact between the at least one grinding element and the clothing in a simple manner, a structure-borne noise sensor is associated with the grinding equipment and an electronic evaluator is capable of determining from the structure-borne noise the intensity of the contact between the at least one grinding element and the clothing.

Abstract: The invention relates to a machining machine for lenses, which comprises a first workpiece drive, configured as the transport receptacle and having a workpiece spindle, a workpiece changer for exchanging workpieces between the workpiece drive and a workpiece stock, and a machining station for machining a workpiece. The workpiece spindle of the workpiece drive can be rotated about an axis of rotation (c1). The workpiece drive can be swiveled about a first swiveling axis (b1) which is arranged at a right angle to the axis of rotation (c1). The work piece drive can be rotated about an axis of rotation (k) which is arranged at a right angle to the first swiveling axis (b1). The machining machine according to the invention is characterized in that at least one further workpiece drive is provided and has a spindle that can be rotated about a respective axis of rotation (c1, c2).

Abstract: For grinding one of axially spaced journal sections of a workpiece each having a cylindrical surface and a pair of shoulder surfaces extending radially outward from the opposite end portions of the cylindrical surface, a rotating grinding wheel is advanced to grind the shoulder surfaces of one journal section and then to grind the cylindrical surface of the one journal section. At the end of the cylindrical surface grinding, the grinding wheel is retracted by a fixed distance at a slow feed rate and is further retracted at a rapid feed rate. A rest shoe provided on the side opposite to the grinding wheel with the workpiece therebetween is advanced to an advanced position where the rest shoe contacts with another journal section axially spaced from the one journal section to decrease the flection of the workpiece caused by grinding resistance and is retracted away from said another journal section when the fixed-distance retraction of the grinding wheel is completed.

Abstract: The present invention is a planarization apparatus for planarizing a coating film applied on a substrate before the coating film is hardened, including a contact body such as a brush or sponge brought into contact with a front surface of the coating film on the substrate; and a contact body drive mechanism for pressing the contact body against the front surface of the coating film and moving the contact body along the front surface of the coating film. The contact body is pressed against the coating film before it is hardened, and moved along the front surface of the coating film, whereby the coating film can be planarized to a predetermined film thickness. According to the present invention, the coating film can be planarized without using the CMP apparatus.

Abstract: The invention relates to a method for rough-honing the peripheral surface (3) of a bore (2). According to said method, a honing tool (5) is introduced into the bore (2), the longitudinal axis (MB) of the bore (2) before rough-honing comprising an off-set (s) relative to the finished bore (2). Said off-set (s) is evened out during rough-honing.

Abstract: A method, device and system for polishing and/or finishing one or more optical fibers. The method comprising securing an optical fiber connector to at least one holder, generating a tilting motion at the end of the optical fiber, adjusting the tilting motion of the optical fiber to create the desired optical fiber end shape and positioning a stage to provide planar motion to the at least one holder. A desired tilting motion of the optical fiber is generated by adjusting tension of at least one spring in operable connection with the at least one holder. Further adjustments to the tilting motion may be accomplished by further changes in tension of the at least one spring. A desired fiber optic end shape may be provided by the method, system and device described herein. Such shapes include dome, circular, or flat.

Abstract: A CNC tungsten steel cutting machine suitably used to cut a metal material, such as tungsten carbide steel, includes an operational platform, a cutting mechanism, a feeding mechanism, a delivering mechanism, and a control panel. When a metal material to be cut is received in a feeding tray of the feeding mechanism, lifting control rods of the feeding mechanism lift the metal material until the metal material is temporarily positioned. Once the latest metal material is completely cut, the lifting control rods push the next metal material, so that the next metal material moves into the V-shaped guiding groove. Then, the delivering mechanism delivers the metal material forward until the metal material is located at a press location of the V-shaped guiding groove. After this, the metal material is cut by a grinding wheel of the cutting mechanism, and then dropped into a collection device adjacent to the operational platform.

Abstract: A polishing apparatus includes a polishing pad for polishing a wafer and a polishing head for holding the wafer. The polishing head includes a retainer ring, a membrane sheet, and a head body. The retainer ring retains the wafer in a horizontal direction. The membrane sheet depresses the wafer to the polishing pad. The head body supports the retainer ring and the membrane sheet. The retainer ring includes a fixed retainer ring and a released retainer ring. The released retainer ring is interposed between the inner periphery of the fixed retainer ring and the periphery of the wafer to retain the wafer in the horizontal direction.

Abstract: The present invention relates to grinding apparatus for grinding the hard metal inserts of rock drill bits, said grinding apparatus having a grinding machine carried on an support system that provides a feed pressure for said grinding machine during grinding, said grinding machine equipped with a grinding pin driven by motor to rotate about its longitudinal axis wherein the grinding cup is rotated at variable speeds and the support system provides a variable feed pressure.

Abstract: A lapping machine includes upper and lower lapping wheels and a sprocket having a common centered rotational axis. A rotational drive source for at least one of the upper and lower lapping wheels provides rotational movement about the axis. At least two independently locatable gears or sprockets disposed radially exterior of the upper and lower lapping wheels rotatably carry a carrier between the upper and lower lapping wheels, in which a material carried within an opening formed in the carrier travels at least partially radially exterior of both lower and upper lapping wheels during operation of the machine.

Abstract: A polishing apparatus includes an arrangement of a plurality of units to deal with various operations and a robot having at least one arm. The plurality of units are disposed around the robot and include a loading unit for receiving thereon a, e.g. dry, workpiece to be polished, a polishing system including at least one polishing unit for polishing the workpiece, a washing system and a drying system at least including one washing unit for washing and drying the polished workpiece, and an unloading unit for receiving thereon a resultant clean and dry polished workpiece.

Abstract: A polishing machine for optical elements, comprising: a spindle arranged to rotationally drive an optical element; a polishing tool mobile relative to the spindle; a front face provided with a door enabling the access to the spindle and to the polishing tool; wherein the polishing tool is mounted on a body which is rotationally mounted on sliding means by way of a first axis, the sliding means being substantially perpendicular to the front face.

Abstract: The spacing between an abrasive type surface polishing tool and the surface of the work piece that is being polished is controlled dynamically so that variations in the area of the abrasive pad in contact with the surface of the work piece compensated, thereby eliminating size variations in this contact area and the accompanying variations in material removal that produce surface height fluctuations.

Abstract: A machining apparatus capable of obscuring periodic machining irregularities. A workpiece W is mounted on a workpiece mounting surface of a worktable, and a tool T is supported by an elastic member (leaf spring) that is attached to a movable unit. A piezoelectric element is provided on the back of the leaf spring, and a driving voltage with irregular frequency and amplitude is applied to the piezoelectric element by a white noise generator during machining. Thus, a relative vibration displacement in a cutting-depth direction (vertical direction) is induced between the tool T and the workpiece W. In the case of a lathe apparatus, a relative vibration displacement is applied in the direction (horizontal direction) of a rotary axis of a workpiece fixture.

Abstract: Methods of refining using a plurality of refining elements are discussed. A refining apparatus having refining elements that can be smaller than the workpiece being refined are disclosed. New refining methods, refining apparatus, and refining elements disclosed. Methods of refining using frictional refining, chemical refining, tribochemical refining, and electrochemical refining and combinations thereof are disclosed. A refining apparatus having magnetically responsive refining elements that can be smaller than the workpiece being refined are disclosed. The refining apparatus can supply a parallel refining motion to the refining element(s) for example through magnetic coupling forces. The refining apparatus can supply multiple different parallel refining motions to multiple different refining elements for example solely through magnetic coupling forces to improve refining quality and versatility. A refining chamber can be used. New methods of control are refining disclosed.

Abstract: The instant invention relates to power tools. More specifically, the instant invention is a portable device for shaping, contouring and polishing the edge of a workpiece consisting of a hard material. The device includes a guide-way constructed and arranged to attach directly to the upper surface of the workpiece. A carriage is slidably supported on the guide-way for movement along the length thereof. Secured to the carriage is a motor for rotation of a rotary tool. A pneumatic cylinder is provided to force the rotary tool into the workpiece with a predetermined pressure along a predetermined axis of approach. The carriage is constructed and arranged for vertical positioning and angular rotation of the rotary tool.

Abstract: An apparatus and method for polishing objects, such as semiconductor wafers, utilizes one or more pivotable load-and-unload cups to transfer the objects to and/or from one or more object carriers to polish the objects. Each pivotable load-and-unload cup may be configured to transfer the objects to and/or from a single object carrier. Alternatively, each pivotable load-and-unload cup may be configured to transfer the objects to and/or from two object carriers. The pivotable load-and-unload cups may be configured to be pivoted about one or more pivoting points over at least one polishing surface, such as a polishing pad surface.

Abstract: The feed system (30) for a honing machine (10) provides a capability to dynamically correct in real time errors in bore size inferred arising from variations in feed force, and a method of operation of the same. The system (10) allows a user to select between rate and force controlled honing modes, which provides one or more of the advantages of both modes. The system provides capabilities for automatic rapid automatic bore wall detection, compensation for elasticity of elements of the feed system (30) and honing tool (14), and automatic tool protection. The system is automatically operable using feed force, feed rate and positional information for honing a work piece (20) to one or more target parameters, such as one or more in-process sizes and a final size.

Abstract: A lens stocking apparatus capable of stocking a plurality of lenses, which has a first stage, on which a plurality of trays respectively accommodating lenses are mountable, for transferring a tray, a vertically movable second stage, on which a plurality of trays respectively accommodating lenses are mountable by being vertically stacked, for receiving a tray, a tray movement unit that has a holding portion, which is adapted to hold a tray, and that is configured to move a tray from the first stage to the second stage, and a guide unit adapted to guide a position of at least a topmost one of trays mounted on the second stage.

Abstract: A method for subaperture polishing includes determining a first portion of a sample to be polished disproportionately compared to a second portion of the sample. Based on the determination of the first portion, a sweep frequency that is a first rate of lateral motion for a polishing pad is selected to be substantially equal to an integer multiple of a rotation frequency that is a rate of rotation for the sample. The method further includes rotating the polishing pad at the polishing frequency, rotating the sample at the rotation frequency, and polishing the sample using the polishing pad while rotating the polishing pad and the sample.

Abstract: The present invention provides an initial position setting method of grinding wheels, before starting a grinding operation, in a vertical double disc surface grinding machine for surface grinding the upper and lower grinding surfaces of a work-piece simultaneously by rotation-driving a pair of grinding wheels by a grinding wheel rotation drive motor and moving the grinding wheels up and down by a grinding wheel vertical drive motor.

Abstract: A centerless grinder for grinding an elongated workpiece includes a grinding wheel having a working surface with a plurality of raised areas extending circumferentially around at least a portion of the working surface. A platform is provided having an elongated top surface for supporting the workpiece substantially adjacent to the working surface of the grinding wheel and a front surface with a plurality of lateral grooves for receiving the raised areas on the working surface of the grinding wheel such that movement of the platform toward the working surface into a working area adjacent to the grinding wheel enables the raised areas to pass into the lateral grooves and grind the workpiece.

Abstract: There is provided a holder for an optical fiber ferrule end face grinding apparatus that can make good use of a grinding film, in which the number of optical fiber ferrules held by the holder is greatly increased. The holder includes a holder plate including a plurality of insertion holes into which each of the ferrules is inserted. In the holder plate, the insertion holes are arranged in an area of a certain size extending from the center to the periphery thereof.