Abstract: An optical amplification apparatus for adjusting optical power of wavelength-multiplexed signal light at respective wavelengths and for adjusting the optical output power at the respective wavelengths and a deviation of the optical output power between the wavelengths. An optical power adjusting unit for receiving inputted light having signal light at a plurality of different wavelengths (&lgr;1, &lgr;2, &lgr;3, . . . , &lgr;N) multiplexed thereon, amplifying or attenuating light at least one wavelength included in the received light independently of light at different wavelengths from the wavelength of the light, is provided before or after an optical amplifier unit for amplifying the light having the signal light at the plurality of different wavelengths multiplexed thereon. Further, a control unit is provided for controlling the gain of amplification or attenuation performed by the optical power adjusting unit and the gain of amplification performed by the optical amplifier unit, respectively.

Abstract: A method and apparatus to enable the use of low cost high RIN optical sources for microwave photonic links by combining the wide-gain bandwidth and low cost of an EDFA, with the narrow gain bandwidth of a Brillouin amplifier. The hybrid Brillouin/EDFA (“hybrid amplifier”) apparatus of the present invention includes at least two couplers, a phase modulator, an Erbium-doped fiber, a laser source to pump the Erbium fiber, an optical circulator, and a length of fiber used for Brillouin amplification. Optical signals from the laser source are split into two optical paths by a polarization maintaining coupler. Optical signals passing through a first path are amplified by the Erbium doped fiber, and the amplified signals are passed through the optical circulator before sending the optical signals into one end of a spool of fiber in order to pump the Brillouin acoustic wave.

Abstract: An optical amplifier is provided comprising an optical fiber ring, and a pump light emitting device providing a primary pump wavelength. The pump light emitting device is optically coupled to the optical fiber ring and utilizes the primary pump wavelength to generate a secondary pump wavelength. Optical signal amplification and secondary pump wavelength lasing occur within the same section of the optical fiber ring.

Abstract: Raman amplification is used in optical transmission systems, devices and/or components. An object of the invention is to provide a new and improved way of proceeding for applying Raman amplification avoiding or suppressing detrimental and hence undesirable non-linear effects when applying Raman amplification to respective optical devices. The invention proposes to apply Raman amplification in an optical device by firstly determining a pump power (3) necessary for providing Raman amplification and then by providing a low spectral power density by pumping the optical device with pump power (3) at a relatively broad pump power spectrum and preferably a low spectral pump power amplitude such that the total output pump power (3) remains sufficiently high.

Abstract: An optical fiber amplifier has a pump module operating at a shorter wavelength at room temperature than conventional optical fiber amplifiers. At the maximum operating case temperature, the output from the pump module is still at a lower wavelength than the upper absorption band edge of the optical fiber. In a further embodiment, an Er—Yb co-doped optical fiber is further doped with aluminum to flatten a portion of the optical absorption profile. Co-doping with aluminum reduces the sensitivity of optical amplifier output to wavelength drift of the pump module when pumped near the secondary peak.

Abstract: A method and apparatus is provided for controlling the optical output power from an optical amplifier arrangement. The arrangement includes a rare-earth doped fiber for imparting gain to an optical input signal propagating therethrough, a pump source for supplying pump power to the rare-earth doped fiber, and a tap for receiving a portion of the output power generated by the rare-earth doped fiber and converting it to a control signal. A controller is also provided for receiving the control signal and generating a bias current in response thereto for driving the pump source. The method begins by receiving an optical input signal that is being amplitude modulated at a prescribed frequency. The slew rate of the controller is adjusted so that the bias current drives the pump source to generate pump power that cannot vary at a rate greater than a slew-rate limit established by the controller. In this way resonance between the input signal and the frequency of the feedback control loop can be avoided.

Abstract: A main object of the present invention is to provide a novel optical power limiting material of high performance being less susceptible to damages caused by heat occurring when an intensified laser beam is irradiated, having reversible characteristic and exhibiting a stable optical power limiting effect; production of the optical power limiting is simple and economical.

Abstract: The apparatus for automatically focusing an image in a microscope includes onto an object plane includes an optical system configured to form an optical image of a sample plane to be observed, an autofocusing detection system, and a focus correction system. The autofocusing system includes an autofocusing light beam source for generating autofocusing light beams. The autofocusing system further includes a detection system lens for directing autofocusing light beams to an autofocusing detection device, and an autofocusing detection device for determining the amount of displacement of the image of the object plane from a desired focused reference plane. The focusing correction system includes a feedback controller and focus adjusting device for automatically adjusting the distance between an objective lens and the sample plane in order to properly focus the image in the optical system. A related method of automatically focusing an image of an object plane in a microscope.

Abstract: In a laser scanning microscope comprising a deflecting device, which is provided for variable deflection of a laser beam about a deflection angle, and a control unit, which controls the deflecting device via a control signal and measures, at least temporarily, a present deflection angle value, it is envisaged that, at the time of measurement of the present deflection angle value, a testing structure, which comprises at least one structural element whose position is assigned to a predetermined deflection angle value, is arranged downstream of the deflecting device, a detecting device is provided, which emits a detection signal when the laser beam is directed to the structural element, and the control unit assigns the present control signal to the predetermined deflection angle value upon reception of the detection signal.

Abstract: A visible light polarizer device includes elements having a different angular orientation with respect to other elements. The elements are sized to interact with visible light to 1) transmit visible light of one polarization orientation, and 2) reflect visible light of another polarization orientation. The device can include 1) primary elements which are substantially parallel with one another, and 2) secondary elements having at least a portion disposed at a different angle orientation with respect to the primary elements. The elements can be configured to transmit visible light of the same first polarization orientation, and reflect visible light of the same second polarization orientation, although they have different angular orientations. Alternatively, the elements can transmit visible light of different polarization orientations.

Abstract: In an optical member having a easy-releasing protective member having ink information for identification on at least one side of front and back side on optical material, wherein the optical transmittance of a portion without an ink information in the protective member is no less than 80%, and an optical transmittance of a portion with the ink information is no less than 90% of the optical transmittance of the portion without the ink information, may be easily identified various kinds of members, to give an identification information on a production line, and to make possible an appearance screening inspection with high accuracy with protective members attached on.

Abstract: A panoramic flash system is disclosed that filters out visible light (but not invisible light) from a flash unit that is directly connected to a camera equipped with a panoramic lens. The invisible light is then used to trigger a remote flash located in a blind spot of the field of view of the panoramic lens. The remote flash then illuminates the scene within the field-of-view of the panoramic lens. The visible-light filter can be an adhesive tape that is placed over the lens of a flash unit that is integral with the camera body. The panoramic lens can have the remote flash unit attached to the lens in the lens' blind spot.

Abstract: An air purge system for an optical sensor is disclosed. The air purge system includes a two sided lens having an optical sensor positioned on the first side and a fluid stream on the second side. The air purge system further includes, a plenum having an inlet, an array of parallel channels and an outlet, whereby the array of parallel channels, is disposed between the inlet and the outlet. The outlet is positioned on the second side of the housing and may be adapted to direct a fluid stream substantially parallel to the second side of the lens.

Abstract: An optical instrument for observation includes, in order from the object side, an objective lens system having positive refractive power, an erecting optical system, and an ocular lens system having positive refractive power. When an anti-vibration mechanism is used to maintain the erecting prism at an orientation in space that is stabilized so as to prevent image degradation due to vibrations of the optical instrument for observation, the erecting prism is constructed to satisfy specified conditions so that ghost light is not generated and so that the optical instrument for observation may be compact.

Abstract: A lamellar volume grating operating in reflection and transmission and providing a substantially wavelength- and polarization-independent diffraction efficiency is disclosed. The lamellar grating has an approximately rectangular grating profile with a height-to-width ratio of the grooves or “teeth” advantageously greater than 2. The grating operates preferably in first order and can be implemented as an immersion grating. In particular, the lamellar volume grating described herein can be employed in an optical multiplexer/demultiplexer arrangement with small overall dimensions.

Abstract: An electrically variable optical filter includes a first optical element including a first angled face and a second optical element including a second angled face. The second angled face is substantially parallel to and spaced apart from the first angled face. At least one separation actuator is affixed between the first optical element and the second optical element and is operable to change a separation distance D between the first angled face and the second angled face. Light waves transmitted through the first optical element are selectively transmitted through to or reflected away from the second optical element as a function of wavelength and the separation distance D.

Abstract: A multilayer film optical filter includes a multilayer film including a plurality of dielectric material thin films repeatedly laminated on a substrate and having different refractive indexes. The multilayer film optical filter further includes a relaxation layer composed of a single material, having a thickness in the range of 1 to 10 &mgr;m, and provided below the multilayer film near the substrate, for relaxing the influence of an error in thickness measurement due to a temperature rise of the substrate in an initial stage of deposition.

Abstract: An original light source or a light source adopting a method to modulate the waveform intensity with a stack of gain-flattening filters includes the following procedures: preparing a stack of gain-flattening filters made of more than two or three aligned single filters, each is made by stacking on a substrate or on both sides of a substrate with several layers of optical films having different refractive indexes; followed by modulating the waveform intensity with a stack of gain-flattening filters installed at the emitting end of the original light source or light source, wherein the angle of each single filter can be adjusted to change the spectrum of a whole set of filters so that the waveform intensity of the original light source or light source is changeable when the emitted original light source or light source is modulated with a stack of gain-flattening filters.

Abstract: A method includes the steps of disposing a substrate having a conductive thin film and a photo-semiconductor thin film in this order on an insulative base in an aqueous electrolyte material that solubility is lowered by a change of pH, irradiating with light a selected region of the photo-semiconductor thin film and precipitating the material to the selected region of the photo-semiconductor thin film to form a micro-lens array layer.

Abstract: EUV exposure apparatus for transferring a pattern on a reticle to a wafer, includes an illumination optical system having a plurality of illumination system mirrors for directing EUV light to the reticle, and a projection optical system having a plurality of projection system mirrors for directing reflection light from the reticle to the wafer. In the illumination optical system, a reflection-type optical integrator is arranged to form a plurality of light source images with the light from the light source. The optical integrator has a pinhole to branch a part of the EUV light to an EUV-light intensity detector. A controller controls the amount of exposure based on the intensity of EUV light detected by the EUV-light intensity detector. In this manner, precision in measuring the intensity of exposure light is improved, and compensation control of the amount of exposure is appropriately performed.

Abstract: A zoom optical system comprises, in order from an object side, a first lens unit having positive refractive power, a second lens unit having positive refractive power, and a third lens unit having negative refractive power. A magnification is changed from a wide-angle position to a telephoto position by moving the lens units toward the object side so as to widen an airspace between the first lens unit and the second lens unit and narrow an airspace between the second lens unit and the third lens unit.

Abstract: This specification discloses a zoom lens having good optical performance over the whole of an object distance from an infinity object to a super-close range object. This zoom lens system comprises, in order from the front to the rear, a first lens unit of positive optical power, a second lens unit of negative optical power, and a following lens component of positive optical power as a whole. During zooming, the first lens unit moves so that the interval between the first lens unit and the second lens unit may become great at the telephoto end relative to the wide angle end. At least one lens unit moves for focusing resulting from a change in an object distance, and the lens unit moving for the focusing is provided with a diffractive optical surface.

Abstract: The invention is directed to lenses having thin walls and a generally conical shape for use with dental light-curing devices. The conical or otherwise tapered shape enables the apex of the lenses to be inserted at least partially within a dental preparation (e.g., a Class II dental preparation). The thin walls allow the light emitted from the light-curing device to pass through the lens and apex without being undesirably refracted, thereby enabling light to be emitted directly in front of the apex with sufficient intensity to cure light-curable compounds within the dental preparation.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength &lgr;1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength &lgr;2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: A lens assembly, which is mounted on a digital still camera (DSC), comprises a fixed aperture, and a lens unit. The lens unit has a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence. The first lens is a biconcave lens disposed at the front side of the lens unit. The second lens is a biconvex lens. The third lens is a biconcave lens. The fourth lens is a positive meniscus lens. The fifth lens is a positive lens. The aperture is arranged between the first lens and the second lens.

Abstract: A lens assembly, which is mounted on a digital still camera (DSC), comprises a fixed aperture, and a lens unit. The lens unit has a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence. The first lens is a negative meniscus lens disposed at the front side of the lens unit. The second lens is a biconvex lens. The third lens is a biconcave lens. The fourth lens is a positive meniscus lens. The fifth lens is a positive lens having a surface, which has a larger curvature radius, facing the image side. The aperture is arranged between the second lens and the third lens.

Abstract: A lens assembly, which is mounted on a digital still camera (DSC), comprises a fixed aperture, and a lens unit. The lens unit has a first lens, a second lens, a third lens, a fourth lens and a fifth lens in sequence. The first lens is a biconcave lens disposed at the front side of the lens unit. The second lens is a biconvex lens. The third lens is a biconcave lens. The fourth lens is a positive meniscus lens. The fifth lens is a positive lens. The aperture is arranged between the first lens and the second lens.

Abstract: A lens-holding frame comprises a frame body and a plurality of elastically deformable lens-holding arms. The arms are supported in a cantilever manner by the frame body and they circumscribe a circle having the same diameter as the lens. A positioning member is provided on the frame body along the circumference of the circle so that the positioning member abuts against the circumferential edge of the lens to define the lens holding position. Each arm is provided with a projection that penetrates inside the circle. The projection has a tapered surface, so that when the circumferential edge of the lens is engaged with the projections and the lens is pushed in toward the positioning member, the arms are elastically pushed open and the circumferential edge of the lens rides over the projections, whereby the lens is held.

Abstract: Disposed in a corner portion formed by a base plate (122) and a vertical wall (124) with being always pressed against the corner portion by a presser bar spring (16), a lens holder (14A) has an adjustment groove (14Aa) extending in a direction perpendicular to the vertical wall. The adjustment groove (14Aa) has a taper shape where a width thereof becomes narrower in proportion to near to the vertical wall and the width thereof becomes wider in proportion to apart from the vertical wall. By moving an adjustment pin (18a) with the adjustment pin inserted in the adjustment groove (14Aa) through a hole (122b) formed in the base plate, the lens holder is moved along an optical axis (OA) of a laser beam, thereby adjusting a position of a beam spread lens (BSL) without a center axis (CA) thereof out of the optical axis.

Abstract: An image-forming device, especially an optical magnifying device, e.g., binoculars or a telescope, has an image influencing optical component, more specifically an eyepiece. The same is held by means of a holding device in such a way that the optical component is axially displaceable along the optical axis of the image-forming device. The holding device comprises a component holding element that is attached to and cannot move relative to the optical component, said component holding element having an adjustment marking, e.g., a dial with a plurality of individual markings reflecting the current axial position of the optical component. The holding device additionally has a marking member to accentuate at least one individual marking on the adjustment marking. With the aid of the marking member the axial position of the optical component can be marked prior to an axial readjustment of the same so that the axial readjustment can easily be reversed.

Abstract: A temperature stabilized optical mirror is disclosed. A rotatable mirror for switching optical light signals between optical fibers is mounted on a support structure. One or more PTC (Positional Temperature Coefficient) resistors are mounted to the support structure to provide heat to the combination support structure and mirror so as to maintain the mirror and support structure above a lower limit of a selected temperature range. The PTC resistor is selected to have a switching temperature substantially equal to the lower limit of the select temperature range.

Abstract: The invention involves a mirror-speaker combination for mounting on a motorcycle. The mirror-speaker combination is comprised of an aft portion and a fore portion. The fore portion is releasably sealed with respect to the aft portion thereby presenting a housing. The aft portion has a concave interior surface. The fore portion has an exterior surface with a mirror-receiving section suitable to accommodate a mirror and with a sound-releasing section with at least one sound-releasing aperture therethrough. The fore portion also has an interior surface. A mirror is attached with respect to the exterior surface of the fore portion whereby a motorcycle operator is able to view objects behind him or her while on the motorcycle. A speaker is attached with respect to the interior surface of the fore portion whereby sound produced by the speaker may exit the housing through the at least one sound-releasing aperture.

Abstract: An optical element formed from a transparent optical material includes two refraction surfaces, a first reflection surface group having a plurality of internal reflection surfaces arrayed in a predetermined direction, a second reflection surface group opposing said first reflection surface group and having at least one internal reflection surface and two side surfaces opposing each other in parallel to the predetermined direction. Light incident from one of the refraction surface is alternately reflected by the internal reflection surfaces of the first reflection surface group and the internal reflection surface of the second reflection surface group and-guided to the other refraction surface.

Abstract: A circular mirror has a frame with peripheral groove and a peripherally mounted gooseneck which is dimensioned to be wrapped around the periphery of the frame and received in the groove. According to the invention, the gooseneck is long enough so that it can be used to support the mirror in a variety of ways. For example, the gooseneck can be extended its full length with its end bent into a hook and then hung from a door. The gooseneck can also be bent into a semi-circle or similar configuration to be used as a table top stand.

Abstract: A wide vision rearview mirror apparatus includes a generally rectangular planar mirror mounted within an elongated mirror housing extending along a longitudinal axis substantially across the windshield of the vehicle, and a pair of spaced adjustable mounts extending from the back portion of the housing for mounting the housing to the windshield. The planar mirror preferably extends at an angle to the longitudinal axis. Each mount comprises a telescopic main body extending generally perpendicular to the housing, and joint mechanisms extending from either end. The joint mechanisms can provide a wide range of adjustments which enable the mirror and housing to be adjusted to suit a wide variety of drivers.

Abstract: A device (21) comprises a movable structure (44) having a first movable portion (70) hinged to a frame portion (60) by a first pair of hinges (81, 82) spaced apart along a first axis (91). The first movable portion (70) has an edge (140) that is substantially parallel with and immediately adjacent to an edge (132) of the frame portion (60), and a first tolerance fit space (120) is defined therebetween. At least two projections (122) extend from one or both of the edges (132 and/or 140). The projections (122) are adapted to limit translational motion of the first movable portion (70) relative to the frame portion (60) within the plane. The projections (122) are substantially adjacent to each other and are on a same side of the first axis (91). The device (21) may also have a second movable portion (80) and a second pivot axis (112).

Abstract: The master information recording apparatus 100 includes a master information carrier, a master information carrier facing member, and a magnetic field applying member. A ferromagnetic thin film pattern formed on the surface of the master information carrier includes not less than two kinds of different patterns each having a different pattern angle showing an angle with respect to the direction of the relative movement between a magnetic head and a rotating magnetic recording medium. The magnetic field applying unit applies a magnetic field along the direction, which is perpendicular to the direction shown by an angle that is smaller than the pattern angle of the maximum pattern and larger than the minimum pattern angle of the pattern among the not less than two kinds of patterns.

Abstract: Synchronized data is written to magnetic tape while reducing the number of backhitches. A controller detects a pattern of synchronizing events for received data records to be written to tape; writes each transaction of data records to the magnetic tape; accumulates the synchronized transactions in a buffer; and subsequently recursively writes the accumulated transactions of data records from the buffer to the magnetic tape in a sequence. A single backhitch may be employed to place the recursively written accumulated data records following the preceding data, maximizing performance and capacity.

Abstract: Special fields for error recovery are provided in data set information tables of data sets written with synchronized transactions. If a transaction only partially fills a data set, that data set is rewritten in a succeeding data set, appending the next transaction. A moving access point in the table identifies the appended transaction, allowing the rewritten transaction to be skipped during read recovery. The table provides recovery trails by providing a thread to tie the data sets together, the status of the data set, and pointers, such as identifying the wrap of the immediately succeeding data set.

Abstract: A recording equalizer for correcting a write timing of magnetic information when the magnetic information is recorded with a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after the recording object bit and a calculator for calculating a precompensation parameter using the bits stored in the buffer. The calculator calculates the preconpensation parameter of the recording object bit by linearly adding influence of a transition existing at a two-previous bit of the recording object bit, influences of a transition at a one-previous bit of the recording object bit and influences of a transition existing at one-following bit of the recording object bit and further adding an offset. The offset is determined to a value such that a write timing of the magnetic information is corrected always in a delaying direction.

Abstract: A magnetic recording and reproducing system is disclosed, which comprises recording a signal on a magnetic recording medium comprising a support having thereon a magnetic layer containing a ferromagnetic powder and a binder, by an inductive head and reproducing the signal by a magneto resistance head, wherein:

Abstract: There is provided a semiconductor integrated circuit for magnetic recording including a write circuit which may be operated with the power supply voltage of 5V system without any problem on the dielectric strength thereof and also assures high speed data write operation to media of the magnetic recording system and a high-speed and highly reliable storage media reading system which has employed the same semiconductor integrated circuit. The write circuit described above is configured to apply a drive voltage to a head through superimposition so that a write current generates over-shoot when the current is inverted by providing the write head with a voltage and moreover a protection element is provided to protect a switch MOSFET for the current switching from a high voltage which is applied to the write head when the current is inverted.

Abstract: A magnetic recording apparatus has a head for recording information on a magnetic recording medium, a write current setting circuit for controlling a write current that is passed through the head, a fault detection circuit for detecting a fault in the head based on the result of comparison between head voltages appearing at both ends of the head and a reference voltage, and a reference voltage setting circuit for varying the reference voltage according to the write current. This configuration permits correct detection of faults in the head all the time irrespective of the write current or the supply voltage.

Abstract: Copying, dubbing or reproducing copyrighted digital data can be inhibited or restricted to properly protect a copyright. AV data recorded on a pre-recorded tape is output from a reproducing unit of a first digital VCR with protective information indicating whether the copy of the AV data is inhibited or not. The protective information is input with the A/V data to a second digital VCR. Copy permission information of a blank tape loaded in the second digital VCR is discriminated and the second digital VCR records the AV data supplied from the first digital VCR based on the protective information and the copy permission information.

Abstract: There is provided a magnetic disk apparatus incorporating a perpendicular recording medium that employs a servo information writing method which is less likely to cause servo errors. A magnetic disk apparatus incorporates a recording medium whose servo areas are so designed that there is at least one point having no servo sector, on the line connecting the recording medium pivot and an arbitrary point on the outermost track of the medium, in a system which satisfies the relation of B×N>2&pgr; where B represents the angle of the area (sector) occupied by the locus of a servo pattern with respect to the recording medium pivot and N represents the number of servo samples.

Abstract: The center of rotation of a disk medium 1 when servo information is written thereto coincides as accurately as possible with its center of rotation in the drive into which the disk medium 1 is assembled.

Abstract: A cartridge for a magnetic recording tape has a first pair of reels rotatably mounted therein which carry a first wide magnetic recording tape, and a second pair of reels disposed therein which carry a second wide magnetic recording tape. The reels are disposed in the cartridge so that each of the first and second wide magnetic recording tapes spans a central space, which is adapted to receive a magnetic recording head of a tape drive, when the cartridge is inserted in the tape drive. A corresponding tape has four drive motors with respective drive shafts, that respectively engage the four reels of the cartridge for transporting the first and second recording magnetic recording tapes across the central opening. The drive has a recording head and a recording head positioning assembly for selectively positioning the recording head at any location along the width of the first and second wide magnetic recording tapes.

Abstract: The magnetic surfaces of the magnetoresistive or magnetic tunnel junction and inductive write head and magnetic recording disk of a hard disk drive are protected from corrosion by inserting a vapor phase corrosion inhibitor (VPCI) package into the disk drive for providing additives in the vapor phase of the disk drive enclosure to maintain an equilibrium and renewable adsorbed film of metal passivators on the head and disk surfaces. The VPCI package includes at least one vapor phase corrosion inhibitor (VPCI) embedded in a polymeric matrix.

Abstract: To provide a car disk drive unit operating in a stable condition which is hardly affected by temperature changes in a vehicle, a car disk drive unit 1 of the present invention comprises: a casing 3 for accommodating a disk drive 2; a Peltier element 4 used as means for controlling the temperature being close to the upper surface of the casing 3 through an intermediate plate 18; a heat sink 5 being close to a base slice 50 on the lower surface of the Peltier element 4; an electric fan 6 for ventilating air to the heat sink 5; and a housing 11 for accommodating the casing 3 in the upper part as well as securing the heat sink 5 and the electric fan 6 to the lower part.

Abstract: A magnetic head for generating a magnetic field for is provided in which first and second electrical contacts are electrically coupled to a thin film wire. An electrical current is passed between the contacts and through the wire to generate a magnetic field. A focus mechanism is provided to focus the magnetic field and thereby increase the flux density of the magnetic field along a recording edge of the thin film wire.