Abstract: A recording/reproduction apparatus includes: a light source; and a near-field light production section that includes two conductor sections disposed opposite each other with a predetermined gap therebetween and that produces near-field light between the two conductor sections upon light irradiation from the light source, the two conductor sections being disposed such that when information is recorded on a recording medium using the near-field light, a direction from one of the two conductor sections to the other of the two conductor sections is generally perpendicular to a line direction of the recording medium.

Abstract: Apparatuses and methods for making and using laser-assisted magnetic recording devices. A slider for use in a magnetic recording apparatus in accordance with one or more embodiments of the present invention comprises a magnetic recording element having a first pole and a second pole, a magnetic reader, and a laser resonator integrally formed on said slider, having an optical emission point of said resonator positioned between the first pole and the second pole of the magnetic recording element; wherein the laser resonator comprises a semiconductor gain media positioned between a first reflector and a near field optical element having a nonzero optical reflection to the semiconductor gain media.

Abstract: A near-field optical head has a planar substrate having a first surface, a second surface disposed opposite to the first surface, and an inverted conical or pyramidal hole extending through the first and second surfaces. The inverted conical or pyramidal hole has at least one fine aperture formed at an apex thereof and disposed in the first surface and having at least one curved slant surface. An optical waveguide extends into the inverted conical or pyramidal hole of the planar substrate for propagating light along an optical path. A mirror is disposed in the optical waveguide for bending in the direction of the fine aperture the optical path of the light propagated through the optical waveguide.

Abstract: A near-field light generating device includes a substrate, a semiconductor laser device, a light absorbing device, and a near-field light generator. The semiconductor laser device is formed on the substrate and emits the laser light polarized in a first direction. The light absorbing device is formed on the substrate to be close to a light emission part of the semiconductor laser device and absorbs light polarized in a second direction orthogonal to the first direction. The near-field light generator is formed on the substrate to be close to a light emission part of the light absorbing device.

Abstract: A near-field optical head includes: a slider which has an opposedly-facing surface which faces a surface of a magnetic recording medium; an optical flux introducing means which introduces the optical flux toward the opposedly-facing surface; a first inclined surface 22 and a second inclined surface 23 which project toward the magnetic recording medium from the opposedly-facing surface in an inclined manner with respect to an optical axis of the introduced optical flux, the first inclined surface and the second inclined surface being arranged adjacent to each other so as to share one side in common; a recording element 13 which is formed on one inclined surface out of both inclined surfaces and includes a main magnetic pole 24 and an auxiliary magnetic pole 26 which are stacked on each other with an insulation film 25 sandwiched therebetween; a metal film 27 which is formed on the other inclined surface out of both inclined surfaces and allows an introduced optical flux to propagate along an interface between

Abstract: There is provided a near field light generating element 22 including a polyhedron core 40 having a reflecting surface 40a configured to reflect a luminous flux L in a direction different from the direction of introduction, a luminous flux condensing unit 40b formed by drawing in such a manner that a cross-sectional area orthogonal to a longitudinal direction extending from the one end side toward the other end side is reduced gradually for propagating the reflected luminous flux toward the other end side while condensing the same; a near field light generating unit 40c further drawn from an end portion of the luminous flux condensing unit to the other end side for generating a near field light R from the condensed luminous flux and emitting the same from the other end side toward an outside; and a clad 41 configured to confine the core in the interior thereof by coming into tight contact with a side surface of the core, in which an end surface 40d has a size not exceeding the wavelength of the light and a sid

Abstract: A thermally assisted magnetic recording method includes the following steps. The recording layer of a magnetic recording medium is irradiated with a laser beam to produce a locally heated region. This heated region is moved by causing the recording layer and the laser beam to move relative to each other. To record desired information, a recording magnetic field is applied to the heated region of the recording layer. The laser beam has a cross section elongated in the direction in which the heated region is moved.

Abstract: An apparatus comprising a slider including a slider substrate with a trailing side and a writer with bond pads disposed on the trailing side. The writer has an optic input for receiving an optic output. The apparatus comprises an optoelectronic substrate having a substrate surface facing the trailing side, and having contacts on the substrate surface that are joined to the bond pads by conductive bridges, and having an optoelectronic emitter adjacent the substrate surface for generating the optic output.

Abstract: The magnetic disk device is capable of securely removing contaminations from an outer face of a magnetic head, maintaining superior recording and reproducing characteristics and improving reliability. The magnetic disk device comprises: a ramp for holding a magnetic head at an evacuating position, the ramp being located outside of a region in which a magnetic recording medium is provided; and a laser emitting section for emitting a laser beam toward the magnetic head so as to heat the magnetic head, the laser emitting section being located in a moving track of the magnetic head, which is moved between the evacuating position and a loading position, without interfering with the magnetic head. An air stream generated by rotation of the magnetic recording medium removes contaminations from the magnetic head when the magnetic head is loaded.

Abstract: An apparatus comprises a moveable arm for positioning an optical transducer adjacent to a storage medium, a stationary light source, and a moveable mirror mounted at a pivot axis of the arm for reflecting light from the light source to the optical transducer. An actuator can be provided for rotating the moveable mirror through an angle of about one half of an angle of rotation of the moveable arm.

Abstract: Components for, and assembly of, a thermally assisted recording device involve a laser mounted to a recording head slider. The output from the laser is directed into an optical waveguide, which delivers the laser light to the media to be written. Several challenges with thermally assisted recording are enabled by the use of a laser carrier, which holds and protects the small, relatively fragile laser and serves as a partial heat sink for the power generated by the laser. The laser, carrier and slider are bonded and can be interconnected as a unit to a suspension constituent to a hard disk drive (HDD) device.

Abstract: The present invention provides a magnetooptic device, a magnetooptic head, and a magnetic disk drive each capable of performing optically assisted magnetic recording and each having a small size, improved recording density, and a higher transfer rate. In a magnetooptic device, a magnetic circuit including a magnetic gap and a thin film magnetic transducer having a coil portion are stacked on the surface of a semiconductor laser. By the arrangement, optically assisted magnetic recording can be performed, small size and light weight are achieved, and higher transfer rate can be implemented.

Abstract: The present invention provides a magnetooptic device, a magnetooptic head, and a magnetic disk drive each capable of performing optically assisted magnetic recording and each having a small size, improved recording density, and a higher transfer rate. In a magnetooptic device, a magnetic circuit including a magnetic gap and a thin film magnetic transducer having a coil portion are stacked on the surface of a semiconductor laser. By the arrangement, optically assisted magnetic recording can be performed, small size and light weight are achieved, and higher transfer rate can be implemented.

Abstract: A magnetic recording medium with excellent signal characteristics is provided in which the stability of recorded information is ensured even when recording is performed in high density or even when magnetic recording and reproduction are performed while the temperature of a recording film is increased by irradiation with light. The present invention provides a magneto-optical recording medium comprising at least a memory layer on a disk substrate, in which the memory layer is separated into magnetic grains to form magnetically isolated recorded domains, or in which a fine structure is formed by an aggregate of mutually isolated magnetic grains in the memory layer, and the memory layer has a large specific resistance. A production method thereof is also provided.

Abstract: A writing current circuit (42) supplies a controlled electrical current to a laser diode (34) for recording data swiftly onto a DVD (16). A plurality of thermometer code registers (52) respectively store numerical values. A current control register (58) receives a numerical value from one of the thermometer code registers (52). Serial data specifies a sequence in which individual thermometer code registers (52) supply values to the current control register (58) thereby causing the writing current circuit (42) to supply a particular electrical current waveform to the laser diode (34). A plurality of current sources (62) respectively receive a single output signal from the current control register (52) which activates or deactivates individual current sources (62) for supplying a particular quantity of current to the laser diode (34).

Abstract: In a recording transducer, radiant energy is incident to be coupled to a recording head via a path defined in the support (e.g., slider) for the head. The radiant energy may be directed via a fiber or lens (e.g., MEMS lens) through a channel defined in the slider. The slider may be keyed to accept the fiber or lens. The process for fabricating the channel in the slider the channel may include wafer level processing to form holes in the slider, to accept the fiber or lens. Wafer level MEM optical processing may be deployed to form integrated MEMS lens structures for an array of sliders.

Abstract: A data recording head having at least two waveguides that are energy-coupled. The first waveguide is end fire coupled to a radiant energy source of a first spot size, and the second waveguide outputs radiant energy of a second spot size onto a recording medium. The width of the first waveguide is larger than the width of the second waveguide, or the first spot size is larger than the second spot size. The recording also includes a cladding layer and/or a diffraction grating for mode index matching between the first and second waveguides. The second waveguide includes a solid immersion optical element to focus the output radiant energy. In one embodiment, the data recording head includes a write element to effect magnetic data recording, and the first and second waveguides are configured relative to the write element and supported relative to the recording medium to effect heat assisted magnetic recording.

Abstract: An optical device integrated head having high light utilizing efficiency by decreasing the propagation loss caused from an optical source to a recording medium, conducting by mounting according to compact active alignment method for efficiently guiding a light generated from a laser device to the top end of a head, in which a light source device mounted on a submount has a mirror portion having an inclinated surface to at least a portion of one edge thereof for reflecting an output light from the optical source device at the inclinated surface, a structural member including a lens structure for further allowing a light to pass through the submount, and an optical waveguide disposed passing through a slider for mounting the submount, and the optical source and the slider are positioned by using active alignment of light in a chip-on carrier structure having the optical source device mounted on the submount.

Abstract: A method for manufacturing a magneto-optical recording medium in which reading of recorded information is performed through domain wall displacement in a reproduction layer is provided, in which magnetic separation of groove side-wall portions is performed more reliably; as a result a magneto-optical recording medium with satisfactory recording and reproduction characteristics can be provided.

Abstract: An optical element for being carried on a slider moving over a recording medium, the optical element being made of a fluid material that transmits light guided from a light source, the optical element which includes a groove an first end which is open and an second end is closed, and a deflection surface for deflecting a light coming from the aforementioned second end of the groove, wherein the thickness of the aforementioned fluid material forming the bottom of the groove is greater on the second end than on the first end.

Abstract: The object of the present invention is to provide an optical recording method for recording data in an optical recording medium, which can reduce jitter of a reproduced signal even in the case where data are recorded at a plurality of linear recording velocities. The optical recording method according to the present invention can record data at a plurality of linear recording velocities or a continuously changing linear recording velocity and a recording waveform for modulating a recording beam includes a direct current section and a recording pulse section. Data are recorded so that the intensity Pbi of the direct current section and the intensity Pw of the recording pulse section satisfy PbiH/PbiL<1 and (PbiH/PwH)/(PbiL/PwL)<1 where PwL and PbiL are Pw and Pbi when data are to be recorded at a linear recording velocity VL and PwH and PbiH are Pw and Pbi when data are to be recorded at a linear recording velocity VH higher than the linear recording velocity VL and satisfying 1.1?VH/VL.

Abstract: An optical information recording method and apparatus which records information on a recording medium by irradiating the recording medium with an irradiation light of a recording power to form a recorded-mark on the recording medium such that reflection coefficient from an area of the recorded-mark is different than a reflection coefficient from an area of the recording medium where the recorded-mark is not formed by a changing power of the irradiation light.

Abstract: A device includes an optical gain medium through which optical radiation is amplified. The device includes first and second reflectors disposed around the gain medium. One of the reflectors includes an emission region though which optical output is emitted and a metallic structure that has an array of features that couple the radiation to at least one surface plasmon mode of the structure, thereby enhancing the device's output. The device may be a laser, e.g., a diode laser. The emission region may have a width of, for example, between 10 and 100 nanometers, and this emission region may be in the shape of a rectangular slit. The optical radiation in the gain medium may be advantageously polarized perpendicularly to an axis along which a longer dimension of the emission region is oriented. The device is useful for data recording, e.g., thermally assisted data recording.

Abstract: A magneto-optical recording medium device of the present invention optimizes a magnetic field forming the front mask and a magnetic field forming the rear mask by use of a single bias magnetic field generator, by shifting the peak position of the bias magnetic field in the magneto-optical recording medium device so as to deviate from the center of the laser beam spot in a tangential direction of the magneto-optical recording medium, enabling extended recording and reproduction margins.

Abstract: A light irradiation head of the present invention includes: a propagation body having a tapered two dimensional shape axially symmetrical to a predetermined symmetrical axis, and consisting of a first kind material that propagates electromagnetic fields of light; and a covering body covering the propagation body so as to surround the symmetrical axis, and consisting of a second kind material different from the first kind material. The propagation body further includes: a bottom edge of projecting shape or recessed shape which is present on the symmetrical axis and which is axially symmetrical to the symmetrical axis; a tip edge which is present on the symmetrical axis and which is narrow relative to the bottom edge; and a pair of reflective edges which are present on both sides of the symmetrical axis and whose interval is gradually reduced in the direction from the bottom edge side to the tip edge side.

Abstract: The present invention proposes a method of controlling the laser power of a semiconductor laser that, in this method of controlling the laser power of a semiconductor laser by applying a power source voltage to between the collector and emitter of an output transistor and a serial circuit of the output transistor and a semiconductor laser, enables decreasing the power consumption of the output transistor. The present invention is arranged to apply a variable power source voltage Vcc to a serial circuit of an output transistor (Qb) and a semiconductor laser (SL) and thereby control the variable power source voltage Vcc such that a difference between the variable power source voltage Vcc and the peak hold voltage of an operating voltage of the semiconductor laser (SL) becomes substantially constant.

Abstract: A disk recording-playback device including a laser drive circuit for feeding a drive signal to an optical head and adjusting the power of a laser beam irradiated by the optical head, an error correcting circuit for detecting an error rate of a reproduced signal, and a system controller for controlling operation of the laser drive circuit for signal reproduction and signal recording based on the output of the error correcting circuit. The system controller successively sets the laser powers to at least three different values, obtains evaluation data for each laser power, approximates the relationships between the laser powers and the evaluation data to a quadratic curve, whereby an optimum laser power is derived corresponding to a vertex of the quadratic curve. Accordingly the optimum reproduction power and recording power are set, to thereby record and reproduce signals with high accuracy.

Abstract: According to the present invention, a light beam is radiated to an area between recording tracks while the intensity of a magnetic field from the outside to a magneto-optical recording medium is suppressed to 50 Oe or less, whereby magnetic anisotropy formed between the recording tracks is set to be lower than that of the magnetic layer on the recording tracks, and micro-domains, for example, having a diameter smaller than a half-width of a light beam for reproduction in a film surface direction are formed on recording tracks. Because of this method, the influence of a leakage magnetic field in the magneto-optical recording medium adopting a DWDD reproducing system is alleviated.

Abstract: An optical storage device decreases the influence of return light to the laser light source and prevents an increase of power consumption even if high frequency superimposing is performed. The optical storage device applies drive current, to which a high frequency signal is superimposed, to the laser light source, and reads/writes data from/in the storage medium. The high frequency superimposing is set to OFF as a default to save power consumption, and high frequency superimposing is turned ON only when it is judged that servo is unstable, and high frequency superimposing is turned OFF when it is judged that servo is stable.

Abstract: A magnetic recording system is provided having a write head employing a combination of magnetic write field gradient and thermal gradient to write data on a ‘thermal spring’ magnetic recording media. The write head comprises a magnetic element using a write current to induce a magnetic write field at the magnetic media and a thermal element using a very small aperture laser to heat a portion of the media. The thermal spring magnetic media comprises [comprises] first and second stacks providing two exchange coupled ferromagnetic layers having different Curie temperatures [The first stack has a high magneto-crystalline anisotropy, a relatively low saturation magnetization and a low Curie temperature.] [The second stack has a relatively low magneto-crystalline anisotropy, a high saturation magnetization and a high Curie temperature.

Abstract: A magnetic recording device is provided according to the present invention for magnetic recording on a recording medium. The magnetic recording device includes a magnetic pole and a C-aperture structure disposed adjacent the magnetic pole. A focusing element receives light from a light source and focuses the received light onto the C-aperture structure, such that the light incident upon the C-aperture structure and a magnetic flux flowing through the magnetic pole are co-locatable on a recording medium disposed adjacent to the magnetic recording device. The focusing element may include a planar waveguide receiving and focusing the light onto the C-aperture structure.

Abstract: The present invention provides a high precision, low cost laser power calibration system. First, the photo signals output from a standard photo diode are received by a photo calibration system; then a set of standards consisting of the corresponding current signals and the power signals are saved in an EEPROM. Finally, the photo diode to be calibrated can be calibrated using the present system in accordance with the calibration standards.

Abstract: A storage apparatus, capable of record or reproduce of an optical information recording medium in which ROM information is recorded with phase pits and RAM information is recorded on top of a recording region of the phase pits, has a main controller that, when the output of the recording information detection system—a system for detecting reflected light of a laser beam from the optical information recording medium and generating signals corresponding to ROM and RAM information—simultaneously contains ROM and RAM signals corresponding to ROM and RAM information, performs negative feedback control of a semiconductor laser emission using ROM signal in the output of the recording information detection system and performs control so as to obtain read-out and played-back ROM signal from the output of an optical intensity detection system for detecting the intensity of the laser light.

Abstract: A method for optically recording information on an optically re-writable information medium is described. A mark is formed on a recording medium by radiating a laser light having the strength of the short recording pulse signal followed by the off-pulse signal. The recording film is heated to form the mark and the mark is extended by thermal diffusion while the off-pulse signal is provided. Therefore, the length of the recorded mark ML is longer than the recording pulse width at a predetermined linear velocity. The erasing pulse signal follows the off-pulse signal and the extended recorded mark is erased by the erasing pulse signal. The recording method according to the present invention can form a mark on the recording medium by radiating the laser light having a shorter recording pulse width than a recording pulse width used in the conventional method to form a mark having the same length.

Abstract: A laser source is located in a relatively cool accessible location. Because there is adequate heat dissipation for the laser source, changes in the laser wavelength that arise from laser temperature changes are minimized. The invention described here includes the use of optical fiber to deliver light from the laser source. The laser reliability is improved because of reduced temperature and temperature fluctuations are experienced by the laser source. Because the laser source can be placed outside the drives hermetic seal, the laser can be easily replaced in the field, if required.

Abstract: A magneto-optical recording medium, a method for recording and reproducing data using the medium and a magneto-optical recording apparatus are provided in which an optical head reads the recorded data while applying a magnetic field, and the ill effect of the leakage magnetic field from the neighboring tracks can be suppressed so as to obtain a correctly read signal. The magneto-optical recording medium includes a recording layer, an intermediate layer and a reproduction layer. The signal recorded in the recording layer is read using a light beam irradiated externally and a magnetic field applied externally. The signal recorded in the recording layer is transferred to the reproduction layer via the intermediate layer. Marks are recorded so that each of leading and trailing edges of a recorded mark is substantially aligned with center portions of a recorded mark or a space of neighboring tracks, and the neighboring tracks have different polarities.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: A method for optically recording information on an optically re-writable information medium is described. A mark is formed on a recording medium by radiating a laser light having the strength of the short recording pulse signal followed by the off-pulse signal. The recording film is heated to form the mark and the mark is extended by thermal diffusion while the off-pulse signal is provided. Therefore, the length of the recorded mark ML is longer than the recording pulse width at a predetermined linear velocity. The erasing pulse signal follows the off-pulse signal and the extended recorded mark is erased by the erasing pulse signal. The recording method according to the present invention can form a mark on the recording medium by radiating the laser light having a shorter recording pulse width than a recording pulse width used in the conventional method to form a mark having the same length.

Abstract: While a magneto-optical recording medium is irradiated with a laser beam, the medium is rotated relative to the beam at a controlled speed in such a manner that a high temperature region of a heat spot produced on the basis of the light intensity distribution of the beam is formed outside the associated light spot. A magnetic field source includes a magnetic field generator which is narrow in the direction along the track of the medium. The field source is positioned with the field generator at the heat center outside the light spot to apply a narrow recording magnetic field to the high temperature region. This forms a recording magnetic domain in the high temperature region. The magnetic domain is rectangular and narrow in the direction along the track. Rectangular recording magnetic domains adjoining in the direction along the track hardly interfere with each other even if they are closely spaced. This results in high density recording.

Abstract: A method of, and apparatus for, defining disk tracks in magnetic recording media. The track-writing apparatus (20) is capable of forming tracks (340) with a track width (TW) and track spaces (350) with a space width (SW) on a magnetic media disk (70) having an upper surface (70S), wherein the disk comprises a magnetic medium with a thermal diffusion length (X). The apparatus comprises, in order along an optical axis (A1), a laser light source (30) capable of providing a pulsed laser light beam (B1), a light pipe (32), and illumination shaping optical system (40) that provides substantially uniform illumination over an exposure region (ER), and a phase plate (60) having a phase grating (210) with a grating period (p), arranged proximate and substantially parallel to the upper surface of the disk so as to form an periodic irradiance distribution (380) at the surface of the disk when the phase plate is illuminated with the exposure region.

Abstract: A magnetic recording device is provided according to the present invention for magnetic recording on a recording medium. The magnetic recording device includes a planar waveguide having a propagation axis. The planar waveguide allows light received thereby to propagate along the propagation axis. The magnetic recording device further includes a magnetic pole having a yoke disposed adjacent the planar waveguide and a pole tip extending into the planar waveguide along the propagation axis. By extending the pole tip into, and incorporating it with, the planar waveguide, the light propagating through the planar waveguide and a magnetic flux flowing through the magnetic pole are co-locatable on a recording medium disposed adjacent the magnetic recording device.

Abstract: An optical information recording method and apparatus which records information on a recording medium by irradiating the recording medium with an irradiation light of a recording power to form a recorded-mark on the recording medium such that reflection coefficient from an area of the recorded-mark is different than a reflection coefficient from an area of the recording medium where the recorded-mark is not formed by a changing power of the irradiation light.

Abstract: Electromagnetic radiation from an optical source is directed onto an optical aperture in a metallic structure. The metallic structure in turn emits optical output from an emission region in the structure and onto a recording medium (e.g., a magnetic recording disk), thereby heating the medium. The optical output is enhanced when the electromagnetic radiation from the optical source includes a frequency that matches a waveguide mode resonance in the metallic structure. Features (such as ridges or trenches) in the metallic structure may be used to further increase the emitted optical output beyond what the emitted optical output would be in the absence of these features. The apparatus and associated method are useful for data recording, e.g., thermally assisted data recording.

Abstract: A magneto-optical recording medium is composed of a base which has a property that a light can be transmitted therethrough, a readout layer formed on the base, which has in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as the temperature thereof is raised and a recording layer formed on the readout layer for recording information magneto-optically. A recording and reproducing method and the optical head are designed for the magneto-optical recording medium. By the recording and reproducing method using the optical head, information recorded at high density can be reproduced.

Abstract: According to the present invention, a light beam is radiated to an area between recording tracks while the intensity of a magnetic field from the outside to a magneto-optical recording medium is suppressed to 50 Oe or less, whereby magnetic anisotropy formed between the recording tracks is set to be lower than that of the magnetic layer on the recording tracks, and micro-domains, for example, having a diameter smaller than a half-width of a light beam for reproduction in a film surface direction are formed on recording tracks. Because of this method, the influence of a leakage magnetic field in the magneto-optical recording medium adopting a DWDD reproducing system is alleviated.

Abstract: Apparatus (10) and method (100) for inscribing a clock pattern (14), detecting the clock pattern (14) optically, and using the clock pattern (14) to write a sevo pattern in an information storage unit (12), such as a computer hard drive. The clock pattern (14) is inscribed using a marking system (64), which may include a laser (66) or employ other, even non-optical, methods. The clock pattern (14) is inscribable into various locations on a disk platter (16) inside the storage unit (12), including many outside the media surface (26) conventionally used for such in data storage units. While the disk platter (16).is rotating, the clock pattern (14) is on detected using an detection subsystem (46), if desired through a transparent window (36) in a hermetically sealed housing (34) of the storage unit (12), for use in writing the servo pattern with less sector-inconsistency error and off-track error.

Abstract: A magnetic recording medium comprises, on a substrate, a recording auxiliary layer, a recording holding layer, recording control layer, and a recording layer. The recording layer is constructed by using a ferri-magnetic material having perpendicular magnetization. The data can be recorded at a super high density by using the recording and reproducing head of the present invention, because the recording layer has the perpendicular magnetization. The disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is suppressed after recording the data, because the recording layer has large coercive force at the room temperature. The data, which is recorded at the super high density on the magnetic recording medium, can be reproduced by using a magnetic resistance element carried on the recording and reproducing head.

Abstract: A magnetic pattern forming apparatus, which is designed to form a desired magnetic pattern on a magnetic disk having a magnetic layer on a substrate, is made up of a mask having a pattern identical or similar to the desired magnetic pattern, a projection optical system for exposing the magnetic disk to a spot-like energy beam coming through the mask to heat the magnetic layer for projecting the mask pattern to the magnetic disk at a one-to-one ratio or a predetermined reduction ratio, a magnetic field applying device for applying an external magnetic field to the magnetic disk, a control unit for conducting scanning with the spot-like energy beam with respect to the magnetic disk and the mask in their radial directions while rotating the magnetic disk and the mask.

Abstract: An encoder converts a binary data word to a binary code word. The encoded bits have first and second binary values at a predetermined clock interval. A pulse generator responds to the encoded bits to generate energizing pulses during each clock interval in which the encoded bits have the first binary value. The energizing pules have a uniform duration less than the clock interval. A laser responds to the energizing pulses for recording on a medium.

Abstract: A method of recording information on and reproducing information from a magnetooptical recording medium which includes first and second magnetic layers. The method includes the step of projecting a light spot onto the medium. When reproducing information, the light spot is projected onto the medium from the side of the magnetic layer. In this method only a high temperature region of the second magnetic layer within a light spot projection portion is changed to a perpendicular magnetization film so that information recorded in the first magnetic layer is transferred to the perpendicular magnetization film of the second magnetic layer. In addition, information which is transferred to the second magnetic layer is detected by using reflected light from the medium which is subjected to the magneto-optic effect from the perpendicular magnetization film of the second magnetic layer.