Abstract: A system, apparatus and method for using modular microscopes is disclosed. Connecting the housings of the individual microscope modules provide the structural framework of the modular microscope. Furthermore, the modular microscope can include specialized software, the distribution and use of which can be controlled using security keys or identifiers stored on one or more of the microscope modules. The security keys and identifiers can be based on calibration data associated with the physical, electrical, or optical properties of one of more of the modules. The illumination modules disclosed provide for selectable wavelengths and controllable levels of output illumination for both bright field and dark field illumination.

Abstract: A polarizing plastic lens comprising a polarizing film with low tendency to detachment from an optical resin layer. There is provided polarizing plastic lens comprising polarizing film constituted of a polyvinyl alcohol resin. Two optical resin layers of different thicknesses may be disposed on both surfaces of the polarizing film. The optical resin layers are formed by polymerizing a polymerization raw material composition in contact with the polarizing film. The polymerization raw material composition contains as one main component an isocyanated or isothiocyanated compound. The iscocyanate or isothiocyanate functional group reacts with the hydroxyl of polyvinyl alcohol resin of polarizing film to thereby form an urethane bond or thiourethane bond, so that the optical resin layers are strongly unified with the polarizing film.

Abstract: A diffusive device has an array of discrete facets which may be of a size and pattern similar to a fractal. The facet dimensions can be greater than half the wavelength of incident light such that the facets substantially diffract light. A polarizing wire-grid layer comprised of an array of elongated parallel conductive wires with a period less than half the wavelength of incident light may be disposed between, beneath, or above the facets. The wire-grid polarizes the light by substantially reflecting light having an s-polarization orientation and substantially transmitting a portion of light having a p-polarization orientation.

Abstract: A polarization device includes an optical stack with a diffraction grating and a wire grid polarizer with one disposed over the other. The wire grid polarizer includes an array of elongated, parallel conductive wires. The diffraction grating includes an array of elongated parallel dielectric ribs.

Abstract: A wire-grid polarizer includes a wire-grid layer disposed over a substrate. A plurality of contiguous dielectric-grid layers are contiguous with one another and disposed directly on top of the wire-grid layer. The plurality of contiguous dielectric-grid layers includes different materials with different indices of refraction. The array of dielectric material elements and the array of metal elements are oriented substantially parallel with one another, and the arrays having substantially equal periods.

Abstract: Provided is a polarizing element, which is made into an assembly of metal elements by utilizing the fact that the plasmon resonance wavelengths of metal elements are different for the polarization direction of a light to irradiate the metal elements. The sum of the geometrically sectional areas of the metal elements in a plane substantially normal to the propagation direction of the irradiating light is smaller than the area of the irradiated region of the light, and the sum of the absorbing sectional areas of the metal elements in the plasmon resonance wavelengths is five times or more as large as the area of the irradiated region.

Abstract: An ester-based polymer to be used in the present invention has at least a repeating unit represented with the general formula (I). A and B are substituents substituted on a stilbene group. R1 is a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group. R2 is a linear or branched alkyl group having 2 to 10 carbon atoms. R3 to R6 each independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group. n is an integer of 2 or more.

Abstract: A double-sided microlens array is applied to a laser beam shaping and homogenizing device of a laser system. The double-sided microlens array is able to shape the energy distribution of an incident laser beam to a square and flat-top beam with the average uniformity of energy and comprises a base plate, a plurality of first micro lenslets and a plurality of second micro lenslets. The first micro lenslet and the second micro lenslet have the convexes with the same figures and comply with the classification of an optical diffractive element, the first micro lenslets and the second micro lenslets are disposed on the first surface and the second surface of the base plate, which are corresponding to each other in order to tightly line up the arrangements of arrays. The first micro lenslets and the second micro lenslets are correspondingly misalignment.

Abstract: Provided is a resonant reflective filter including a substrate and a grating layer, wherein the substrate is formed of a material having a lower reflective index than that of a material forming the grating layer. Thus, the resonant reflective filter can form a resonant spectrum having good symmetry and a sharp shape. Accordingly, the resonant reflective filter can have improved sensitivity and can be applied to optical systems that require a small linewidth.

Abstract: An optical arrangement includes a light source which emits coherent light of a wavelength ?, and a diffraction grating which has a multiplicity of diffraction structures which follow one another periodically at the spacing of a grating period d and are arranged along a base surface, the individual diffraction structures respectively having a blaze flank and an antiblaze flank, the blaze flanks being arranged at an angle ? and the antiblaze flanks being arranged at an angle ? to the base surface, and respectively neighbouring blaze and antiblaze flanks enclosing an apex angle ?, and an incident light beam being arranged at a Littrow angle ?L relative to a grating normal of the diffraction grating.

Abstract: An anti-reflection sheet is formed in a manner of forming a resin layer, which has many fine projections 12, on a flat and smooth surface of a transparent substrate 11. Transparent resin is molded into the projections 12, the projections 12 have an almost quadratic function-shaped cross section including a center axis C perpendicular to the surface of the substrate 11, and a surface of the projection 12 is preferably a rotational paraboloid. A ratio (aspect ratio) b/a of a height b and width a of the projection 12 is 1 or less. Additionally, an arranged pitch P of the projections 12 is not more than half of a wavelength of incident light.

Abstract: An optical sheet, which can suitably absorb external light over a wide range and can improve a contrast, a display device, and a method for producing an optical sheet. The optical sheet is disposed on an observer side relative to an image light source and includes: a plurality of layers that control light emitted from the image light source to emit the light on the observer side, wherein at least one of the plurality of layers is an optical functional sheet layer which includes prisms being arranged in parallel along the surface of the optical sheet whereby light can be transmitted and wedge portions are arranged in parallel between the prisms whereby light can be absorbed. At least one of the plurality of layers other than the optical functional sheet layer is a light-absorbing layer.

Abstract: A beam direction control element has transparent areas and light absorption areas alternately arranged on a surface of a substrate, wherein the light absorption areas function as a louver for controlling the direction of a beam of light. The beam direction control element is manufactured by disposing an optically transparent material on a first transparent substrate to form transparent ridges which constitute the transparent areas, filling curable and photo-absorptive fluid in gaps between the transparent ridges, and then curing the fluid to form the light absorption areas.

Abstract: An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

Abstract: The present invention comprises methods and apparatuses for causing a single imaging lens system to simultaneously form multiple high resolution images on multiple imaging sensor planes. The images are preferably substantially identical, with no parallax error, except for different light levels so that the multiple images are of sufficient quality and similarity that they may be compared and/or combined (typically pixel-by-pixel) to create a single instantaneous high dynamic range (HDR) image. The invention may be used to create high-resolution HDR snapshots of moving subjects, as well as high-resolution HDR moving pictures (e.g. cinematographic films, movies, or other video) in which the subject and/or camera is moving. Alternatively, the images are substantially identical, or substantially identical except for different focuses.

Abstract: An optical element includes a container including first and second end face walls, a side face wall, and an accommodating chamber inside the walls; first and second liquids enclosed in the chamber; a first electrode provided on a surface of the first end face wall; a second electrode provided on a surface of the second end face wall; an insulating film provided on a surface of the second electrode; and a unit configured to apply a voltage. The shape of an interface between the liquids is changed by a voltage application, and a light transmission path, the center of which is a virtual axis passing through the end face walls in the thickness direction of the container, is formed in a portion of the second liquid. An opening having a diameter the same as or larger than the maximum diameter of the transmission path is provided in the first electrode.

Abstract: A variable focal length lens includes: a lens portion including a pair of light transmissive members, at least one of which is deformable, and a light transmissive liquid medium sealed between the pair of light transmissive members; and a liquid medium container including a chamber that communicates with the lens portion and is filled with the liquid medium, the liquid medium container causing the shape of the surface of the deformable light transmissive member or members to be changed by changing the volume of the chamber to adjust the amount of liquid medium with which the lens portion is filled.

Abstract: The zoom lens includes, in order from an object side, a first lens unit (positive), a second lens unit (negative), a reflective member and subsequent lens units. A distance between the second and subsequent lens units is reduced during zooming from a wide-angle end to a telephoto end. One of the subsequent lens units includes a non-shift lens unit and a shift lens unit shiftable for image stabilization. The conditions of 1<(1??b)?r<3 and 0.70<Lb/Lp<2.00 are satisfied. ?b and ?r represent lateral magnifications of the shift lens unit and all lens units disposed further on the image side than the shift lens unit when the zoom lens is focused on an infinitely distant object at the telephoto end. Lb represents a distance from an image side surface of the reflective member to an object side lens surface of the shift lens unit. Lp represents a thickness of the reflective member.

Abstract: A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group, in this order from the object. Upon zooming from the short focal length extremity to the long focal length extremity, all of the first through fourth lens groups move along the optical axis. The zoom lens system satisfies the following condition: 3<T1/F2<4 ??(1) wherein T1 designates the traveling distance of the first lens group upon zooming from the short focal length extremity to the long focal length extremity; and F2 designates the focal length of the second lens group.

Abstract: A linear guide mechanism of a lens barrel, the lens barrel including a rotatable ring, and a linearly movable member which holds an optical element and moves linearly in an optical axis direction by rotation of the rotatable ring, the linear guide mechanism includes a plurality of partial linear guide members which linearly guide the linearly movable member in the optical axis direction. A movement range of the linearly movable member in the optical axis direction is shared by a plurality of different movement ranges, via which the linearly movable member is linearly guided in the optical axis direction by the plurality of partial linear guide members, respectively.

Abstract: A zoom lens includes a variable aperture-stop mechanism positioned in front or behind an aperture-control lens group; a first rotation imparting member, which rotates an opening/closing ring of the variable aperture-stop mechanism by a relative movement between the variable aperture-stop mechanism and the first rotation imparting member in the optical axis direction so as to hold an adjustable aperture of the variable aperture-stop mechanism at a small aperture size when the aperture-control lens group moves within in the zooming range; and a second rotation imparting member, which rotates the opening/closing ring by a relative movement between the variable aperture-stop mechanism and the second rotation imparting member to open and hold the adjustable aperture at a large aperture size when the aperture-control lens group moves to the accommodated position, at which the aperture-control lens group is partly positioned in the adjustable aperture held at the large aperture size.

Abstract: An image pickup lens, comprises sequentially from an object side: an aperture stop, a first lens being a positive meniscus lens which has a convex surface at the object side and a concave surface at an image side opposite to the object side, and a second lens having a concave surface at the object side and an image side surface whose radius of curvature on an paraxial region is infinite or a negative value, wherein the first lens is the second lens and the image side surface of the second lens includes an aspheric surface to make a positive power strong toward a lens peripheral region, and wherein the image pickup lens is made to satisfy the following conditional formulas. 1.55<n1<1.80??(1) 0.4<D3/f<0.6??(2) 40.0<?2<90.

Abstract: A lens holder of a stacked lens module and a manufacturing method thereof are revealed. A stacked lens submodule is used as a molded molding insert to be set into a mold cavity. The molding insert is aligned in the alignment fixture and the clamp of the mold by injection molding or press molding. After molding process, a lens module included the stacked lens submodule as well as the lens holder is formed. Thereby the manufacturing method of conventional lens assemblies or lens modules is improved. Moreover, the processes are simplified and the yield rate is increased. Furthermore, the molded lens module is packed into the lens more easily so that it is suitable to be applied to camera lenses, small lenses and mobile phone lenses.

Abstract: An exemplary lens module includes a barrel and a first lens. The barrel includes a cylindrical sidewall. The sidewall defines an accommodating space therein and has an opening defined therein. The opening communicates with the accommodating space. The first lens is received in the accommodating space of the barrel. The first lens has a first adjusting notch defined at a periphery thereof. The first adjusting notch is exposed at the opening of the barrel.

Abstract: A camera device includes a housing, a lens module, a holder, an image sensor, a driving apparatus, and an elastic member. The housing includes a front housing and a back housing. The lens module is assembled on the outer surface of the front housing away from the back housing. The holder is received between the front housing and the back housing, the holder is movable along the optical axis of the lens module and defines a screw hole thereon. The image sensor is fixed on the holder and facing the lens module. The driving apparatus is fixed on the back housing, the driving apparatus includes a motor and a lead screw rotated by the motor, the lead screw is inserted into and meshing with the screw hole for moving the holder. The elastic member has two ends thereof connecting to the holder and the back housing respectively.

Abstract: The present invention relates to an image photographing device, and is invented to absorb vibration of the plate spring when the lens holder is moved, thereby stabilizing rapidly the lens holder. According to one example, the small camera provided with a damper includes a lens holder provided with lens and driven in an optical axial direction, a fixing unit housing the lens holder, a plate spring which is arranged to the upper part or lower part of the lens holder and connects the lens holder to the fixing unit and supports it so that the lens holder is moved in an optical axial direction, a driving unit for driving the lens holder in an optical axial direction, a support unit arranged on the lower parts of the lens holder and the fixing unit, and a damper member attached to the plate spring for absorbing vibrations of the plate spring wherein the damper member is made with polymer chemical having an elastic force and the elastic force of the damper member is smaller than that of the plate spring.

Abstract: A clutching jig used to disengage a lens socket and a lens component which has a base glued on a printed circuit board (PCB) and is fixed in the lens socket by a plurality of buckling pieces of the lens socket abutting on the lens component. The clutching jig defines a base plate. The base plate has an inserting hole at a middle portion thereof. A side of the base plate has a portion surrounding the inserting hole extended perpendicular to the base plate to form a plurality of inserting slices, enclosing a chamber for receiving the lens component. The inserting slices are adapted to insert into a gap between the lens component and the lens socket for pressing the buckling pieces away from the lens component, with distal ends of the inserting slices extending inwards beyond a junction of the base and the PCB.

Abstract: A lens module includes a lens barrel and a lens holder. The lens barrel includes a barrel. The barrel includes an outer surface and an outer thread portion formed on the outer surface. The lens holder includes a main body. The main body defines a receiving space to receive the lens barrel. An inner thread portion matching the outer thread portion is formed on an inner surface of the receiving space. The angle between the outer surface of the lens barrel and an optical axis of the lens module is different from the angle between the inner surface of the receiving space and the optical axis of the lens module.

Abstract: An apparatus and a method are provided. The apparatus including: a light expander configured to expand light, input into the light expander, in a first dimension, and configured to provide diverging light that diverges in the first dimension; and an optical device configured to redirect diverging light, received from the light expander, to produce converging light that converges in the first dimension.

Abstract: A damper is provided for a rear view mirror with motorised actuation. A damper is provided between the mirror and its frame assembly for the purpose of shock absorption or vibration reduction. Each damper comprises a bracket and a boss. A polymer contact material such as an O-ring 24 is mounted onto the free end of the bracket and contacts the boss. The frictional and elastic properties etc. of the contact material determine the damping and frictional characteristics of the movement of the mirror with respect to the boss.

Abstract: A switching mechanism for a camera includes: a control unit; a driving device coupled with and actuated by the control unit; a first gear set coupled with the driving device; a second gear coupled with the first gear set and centrally provided with a rotary shaft having a shaft hole formed with threads; a spindle being female-connected to the shaft hole and which has an axial surface formed with outer threads corresponding to the threads of the shaft hole, thus allowing the second gear to move along and relative to the spindle; and a translation member positioned perpendicular to the spindle and provided with a rack for engaging with the second gear and thus driving the translation member to move perpendicular to the spindle. The second gear drives or does not drive the rack as the engagement therebetween is made or broken.

Abstract: A display filter includes a base substrate disposed in front of a display module, an optical film laminated on the surface of the base substrate that faces a user, and a hard coating layer formed on the surface of the base substrate that faces the display module. The hard coating layer prevents the base substrate from being deformed.

Abstract: A system for determining vibration of at least one hard disk drive includes one or more computers configured to command a plurality of reads from the at least one hard disk drive such that, for each of the plurality of reads, data stored on the at least one hard disk drive is retrieved directly from the at least one hard disk drive. The one or more computers are also configured to obtain read rate information related to the plurality of reads and to determine a vibration level experienced by the at least one hard disk drive based on the read rate information.

Abstract: A spin torque oscillation magnetoresistive sensor for measuring a magnetic field. The sensor uses a change in precessional oscillation frequency of a magnetization of a magnetic layer to determine the magnitude of a magnetic field. The sensor can include a magnetic free layer, a magnetic pinned layer and a non-magnetic layer sandwiched therebetween. Circuitry is connected with these layers to induce an electrical current through the layers. Spin polarization of electrons traveling through the device causes a spin torque induced precession of the magnetization of one or more of the layers. The frequency of this oscillation modulates in response to a magnetic field. The modulation of the oscillation frequency can be measured to detect the presence of the magnetic field, and determine its magnitude.

Abstract: A magnetic recording apparatus includes: a magnetic recording medium having a recording surface on which a plurality of magnetic recording cells magnetically isolated from each other are arranged; a magnetic writing element recording information to the magnetic recording cells under a condition in accordance with setting information; a magnetic reading element reproducing information recorded in the magnetic recording cells; a memory storing the setting information for writing; and a processor for executing a program code.

Abstract: According to one embodiment, a disk drive includes a disk medium, a read controller configured to perform a read control for information in the disk medium, a determiner configured to determine whether or not to ignore a read error in information as a read target depending on a type of the information, and a transmitter configured to transmit the information to a host device without read error detection for the information read by the read controller if the determiner determines to ignore the read error.

Abstract: Embodiments include methods, apparatus, and systems for servo write head gap width correction. One method includes measuring a pulse mismatch for servo stripes on magnetic tape written with a servo write head having servo head gaps with different physical sizes, and separately energizing the servo head gaps to correct the pulse mismatch so servo stripes written on the magnetic tape are within a predefined tolerance.

Abstract: A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module comprises two synchronous servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted parameter estimate and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. An offset computation module provides first and second offset terms which are summed with the unweighted parameter estimates. Multiplying nodes receive the unweighted parameter estimates and the weight signals and outputs offset weighted parameter estimates. A summing node receives the offset weighted parameter estimates and outputs a combined offset weighted parameter estimate to a servomechanism.

Abstract: According to one embodiment, a magnetic disk storage device includes a magnetic disk, a head, a clock generator, an estimating module, and a controller. The magnetic disk includes a servo area and a corresponding data area, and has a surface divided into zones in the radial direction. The basic frequency varies in the servo area depending on the zones. The head is driven to read a signal from the magnetic disk. The clock generator generates a clock signal for decoding a signal read from the data area corresponding to the servo area based on a signal read from the servo area. The estimating module estimates the position of the servo area in the radial direction, from which the head reads a signal next. The controller controls the clock generator to generate a clock signal of the basic frequency before the head reaches the servo area based on the estimated position.

Abstract: A method of storing data includes receiving general purpose (GP) data and special Error Tolerant or Streaming (ETS) data, storing the GP data using a data storage method, and storing the ETS data using a different data storage method which affects the access rate, resilience to errors, data integrity, storage density, or storage capacity. The storage medium, which can include a disk drive, flash memory, or holographic memory, is utilized differently depending on the required Quality of Service in aspects including block size, storage of error correction codes, utilization of error correction codes, storage area density, physical format pattern, storage verification, or reaction to failed storage verification. For disk drives these differences include spacing between tracks; overlap between tracks; spiral track formatting; concentric track formatting, and size of blocks, and for flash memories these differences include levels per cell and number of cells.

Abstract: A near-field light generating element accommodated in a groove of an encasing layer has an outer surface that includes a first end face including a near-field light generating part, a second end face opposite to the first end face, and a coupling portion that couples the first and second end faces. The coupling portion includes a top surface, and first and second side surfaces that decrease in distance from each other with increasing distance from the top surface. The first end face includes a first side located at an end of the first side surface, and a second side located at an end of the second side surface. Each of the first and second sides includes an upper part and a lower part continuous with each other. An angle formed between the respective lower parts of the first and second sides is smaller than that formed between the respective upper parts of the first and second sides.

Abstract: An integrated heat-assisted magnetic recording (HAMR) device comprises a slider that has a top surface, a bottom surface, and a trailing end. A waveguide is carried on the trailing end and a near field transducer is positioned to receive energy from the waveguide and produce plasmons for heating a region of a magnetic medium. A write pole is carried by the slider adjacent to the near field transducer. A laser is mounted on the top surface of the slider and produces a laser beam that passes through a beam shaper mounted on the top surface of the slider that collimates or focuses the laser beam. A mirror is mounted on the slider for directing the collimated or focused light beam into the waveguide.

Abstract: Magnetic element with thermally-assisted magnetic-field writing or thermally-assisted spin-transfer writing, comprising: a reference magnetic layer having a fixed direction magnetization; a storage magnetic layer exchange-pinned with an antiferromagnetic layer, wherein the magnetization direction of the storage layer can vary when said element can be heated to a temperature at least higher than a critical temperature of the antiferromagnetic layer; a tunnel barrier, provided between the reference layer and the storage layer; wherein the magnetic reference layer, and/or the magnetic storage layer includes at least one electrically-resistive thin layer for heating the magnetic element. The magnetic element disclosed herein has a voltage gain of typically 10 to 50% compared to conventional magnetic elements and shows a reduction of the stress induced during a writing operation as well as a reduction of the ageing.

Abstract: In one embodiment, a method for removing a resist includes irradiating, with an UV light having a wavelength of less than about 240 nm, a structure having a resist on a pattern surface in an atmosphere having oxygen. The resist is used as a mask as it remains above the pattern after the pattern has been transferred to a magnetic recording medium surface having a magnetic film thereon, and the irradiating is performed during production of the magnetic recording medium. In another embodiment, a method for forming a magnetic recording medium includes applying a resist to a surface of a magnetic film above a substrate, curing the resist by irradiating the resist with first UV light to form a pattern, transferring the pattern to the magnetic film using the pattern, and removing the resist by irradiating using second UV light having a shorter wavelength in an atmosphere including oxygen.

Abstract: A disk drive. The disk drive includes a head, an actuator, and a controller. The head accesses a disk. The actuator is configured to support the head and to move the head by action of a voice-coil motor in a substantially radial direction of the disk. The controller is also configured to perform servo control of the actuator by using servo data read out by the head. The controller includes at least one of a plurality of notch filters having a fixed center frequency inserted in a servo-control loop. The controller is configured to increase an attenuation rate by at least one of the plurality of notch filters having the fixed center frequency at a designated frequency, when a target position of the head is at a position selected from the group consisting of a position outside of a specified region and a position within the specified region.

Abstract: A method of controlling a writing or reading operation of a disk drive. The method includes determining whether a writing control signal or a reading control signal, and a flying height control signal to control a flying height of a head are in enabled states, and when the writing control signal or the reading control signal and the flying height control signal are in the enabled states, performing the writing operation or the reading operation.

Abstract: According to one embodiment, a magnetic disk device includes a receiver, a storage module, a determining module, and a prescanner. The receiver receives a command from a host device. The storage module stores, with respect to each of divided areas formed by dividing the recording area of a recording medium into a plurality of areas, pre-scan control information indicating at least one of the receiving time and the number of receiving times. The receiving time indicates a time at which a write command is received. The number of receiving times indicates the number of times the write command is received within a predetermined period after the power is turned on. The determining module determines the order in which pre-scan is performed on the divided areas based on at least one of the receiving time and the number of receiving times. The prescanner pre-scans the divided areas in the determined order.

Abstract: A disk drive. The disk drive includes a head, a motion mechanism, and a controller. The head is configured to access a disk configured to store data. The motion mechanism is configured to move the head. The controller is configured to determine a seek direction when an error occurred; and, the controller is configured to repeat a seek as a repeat seek to a target radial position from a direction opposite to the seek direction in an error-recovery process for the error which occurred in the seek in which the head moved to the target radial position.

Abstract: A control apparatus connectable to a memory unit for storing data, for controlling a first tape writing unit including a plurality of first tapes and a second tape writing unit including a plurality of second tapes so that the first and second writing units write same data stored in the memory unit to one of the first tapes and one of the second tapes, respectively, has an obtaining unit for obtaining a progress value indicating a progress of writing data into the one of the second tapes upon completely writing the data into one of the first tapes and a controller for controlling the first and the second tape writing units so that the first and the second writing unit change the writing tapes to another of the first tapes and another of second tapes when the progress value being not more than a predetermined value.

Abstract: Due to a difference in coefficient of linear expansion between the constituent material of the flange and the constituent material of the base of the feedthrough, the solder material which joins these materials is unable to withstand the thermomechanical loading that is generated between these heterogeneous materials during their actual usage for a long period and, as a result, cracks formed in the solder-joined portion therebetween create low-density gas leakage paths that reduce actual lifespan to less than 5 years. Disclosed is a magnetic disk device comprising a magnetic disk, a magnetic head for recording and reproducing information onto and from the magnetic disk, a base, a feedthrough solder-joined to the base, and a solder-joined portion for joining the base and the feedthrough, wherein a recess portion is provided in the perimeter edge of the solder-joined portion of the base.