Abstract: An optical information handling device in which reflectivity of the conventional reproduction-only type optical disk is lowered to 60% or less and is made equal to the reflectivity of write-once type and rewritable type optical disks, whereby interchangeability in these of these disks is possible.

Abstract: The present invention provides an optical recording medium using an amorphous-crystalline phase-change for recording and erasing, wherein reflectivity of an optical recording medium-constituting recording film in an amorphous state is larger than that of the optical recording medium-constituting recording film in a crystalline state, or wherein absorptivity of an optical recording medium-constituting recording film in an amorphous state is smaller than that of the optical recording medium-constituting recording film in a crystalline state.

Abstract: The information processor uses a portable memory formed on a transparent substrate which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium rotatably incorporated within a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through the case which has at least a transparent light-incident portion. The case includes therein a rotation means for rotating the recording medium within the case, thereby enabling even further reduction in size of the information processor.

Abstract: A motor has a stator and a rotor, the stator having cores and drive coils which generate magnetic fields for rotating the rotor. The stator also has a yoke surrounding the rotor and the rotor is positioned such that it is closer to one part of the outer periphery of the yoke than another part of the outer periphery of the yoke. Such a motor is particularly suitable for use in a disk drive unit as a spindle motor for rotating the disk. Then an actuator for moving a head may be located adjacent the part of the outer periphery of the yoke which is closest to the rotor. This permits the head to approach closely the axis of rotation of the disk without the spindle motor interferring with the movement of the head. The continuous yoke prevents magnetic flux leakage from the spindle motor interferring with the actuator. The actuator may itself have a yoke integral with the yoke of the spindle motor, and/or other components in common.

Abstract: The invention relates to an optical memory in which an optical recording medium is built in a case, and also to a memory apparatus. Recording, reproducing and erasing operations are performed by irradiating light via a transparent portion of the case onto the built-in optical recording medium. The optical recording medium built in the case has face vibrations with respect to the case, because it is moved within the case. The present invention is characterized by employing such a construction for optically mitigating irregular fluctuation in reflectivity caused by this face vibration. In the optical memory of the present invention, the reflectivity fluctuation caused by an interference effect made between reflection light from the case and air, and also reflection light from the optical recording medium and air due to the relative deviation in the face vibrations, may be reduced by antireflection films provided in the case and the optical recording medium.

Abstract: There is provided a compact and thin optical disk unit as a memory unit suitable for a portable computer such as a book type computer and a portable recording/reproducing apparatus. In the optical disk unit, the diameter of an objective lens is limited and a beam shaping prism, a beam splitter, a mirror and a 1/4 wavelength plate are formed into a unitary structure to make easy the optical axis adjustment of an optical head and ensure highly accurate assembling.

Abstract: An overwritable optical disk apparatus in which a finite conjugate optical system is employed. The apparatus comprises an optical head for converging diffused light from a light source onto an optical disk for performing data write/read operation, a driving unit for rotating the disk and a beam splitter for guiding the light reflected from the optical disk to a photodetector for detecting light reflected from the optical disk. Influence of disk displacement occurring in accompanying the rotation of the disk and disk eccentricity are suppressed to a minimum by encasing rotatably the optical disk within a credit card size casing which is adapted to be loaded and held stationarily in the optical disk apparatus. Thin structure of the optical head and miniaturization of the optical disk apparatus are realized with light utilization efficiency for data write/read operation being increased.

Abstract: The information processor uses a portable memory which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium incorporated rotatably in a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through this case.

Abstract: An information recording and erasing method and apparatus of an optical memory medium including a substrate, a guard film, and an intermediate layer portion so disposed between said substrate and said guard film as to include at least a recording material layer having a phase changing with temperature and include at least one good conductor layer, comprising the steps of supplying magnetic flux varying relatively to said good conductor layer to generate eddy currents within said good conductor layer, and heating said recording material layer with heat generated in said good conductor due to the eddy current loss to effect information recording and erasing with respect to said recording material layer.

Abstract: An optical modulation method and apparatus uses superconductive oxide material for the optical modulation element. The current, magnetic field, temperature or pressure applied to the superconductive oxide material is varied so as to induce a superconduction-normalconduction transition, and the resulting variation in optical characteristics such as the reflectivity, transmissivity or refractive index of the superconductive oxide material modulate the input light. The method and apparatus are fast in operation and simple in structure. The method and apparatus also detect the variation in the current, magnetic field, temperature or pressure as a change in the reflectivity, transmissivity or refractive index of the superconductive oxide material on the basis of a superconduction-normalconduction transition.

Abstract: An optical recording sheet includes a plurality of data columns consisting of optical recording dots arranged in a matrix shape and column markers corresponding to the data columns. The data columns and the column markers of the optical recording sheet are detected by an optical line sensor and stored in a memory. On the basis of information stored in the memory, a marker detector detects the column marker and then two memory coordinates having a position known relative to the column marker are calculated. From the two memory coordinates, an inclining angle detector calculates the inclining angle between the optical recording sheet and the optical line sensor. On the basis of the memory coordinates and the inclining angle, an address calculator restores the optical recording dots stored in the memory coordinates.

Abstract: An electrostatic actuator includes a stationary element and a movable element. The stationary element has a surface which faces a surface of the moving element. Both the surface of the stationary element and the surface of the moving element have electrode lines disposed thereon, including a first set of parallel electrode lines and a second set of parallel electrode lines which are perpendicular to the lines in the first set. By facing the stationary surface and the movable surface towards each other such that the electrode lines of such surfaces are aligned, the movable element can be moved along either of two perpendicular axes when a voltage is applied to the electrode lines.

Abstract: A waveguide path type optical pickup is provided for preventing a returning light from returning back to a light source. A filter for selectively allowing either Te polarized light or TM polarized light to pass through the filter is provided in an optical path from a light source to an optical path deflector. An optical part for changing the polarized state of light is provided in an optical path from the optical path changing part to an information recording medium, thereby prevent a reduction in S/N ratio or reproducing signal.

Abstract: An optical head including a substrate, an optical waveguide formed on the substrate, a light source formed on a portion of the substrate, a collimator lens for converting light from the light source into parallel light rays, an objective lens for focusing light from the collimator lens onto a recording medium and for converting reflected light from the recording medium into parallel light rays, a beam splitter for dividing light from the objective lens into two parts to send out one of the parts in a predetermined direction, a coupling lens for focusing light from the beam splitter on a position, and a photodetector for detecting light from the coupling lens, is disclosed, in which the collimator lens, the objective lens, the beam splitter, the coupling lens and the photodetector are integrated on the substrate, and the collimator lens or an objective lens supporting part is made flexible to vary the position of the focus of the collimator lens or objective lens by piezo-electric elements.

Abstract: An optical head is disclosed, in which a plate-shaped optical wave guide comprises an optical system including a collimator lens, a beam splitter and an objective lens; a laser light source for emitting a laser light in the form of a light beam which is to be impinged on an optical recording medium; and electro-acoustic transducers are disposed between the beam splitter and the objective lens, the transducers being adapted to be driven by the outer electrical signal for producing surface acoustic waves in the optical wave guide, thereby establishing a condensation and rarefaction distribution in refractive index in the optical wave guide which distribution influences the direction of transmission and the degree of focusing of the light beam passing therethrough so that regulation of the tracking and the focal length can be effected without any mechanical movements.

Abstract: A light spot determining a first condition that an optical recording medium is cooled after being heated to a temperature exceeding a first temperature and a light spot determining a second condition that the optical recording medium is cooled after being heated to a temperature exceeding a second temperature higher than the room temperature and not exceeding the first temperature higher than the second temperature, namely, the two light spots are radiated onto the optical recording medium and in the same guide track thereof wherein signals are recorded and erased on the optical recording medium by controlling the spot diameter of each light spot and/or the light intensity thereof.

Abstract: A laser light flux is divided and synthesized so that its light intensity distribution is changed from a Gaussian distribution to a non-Gaussian distribution. When a laser light flux having a Gaussian distribution is irradiated onto a dividing prism, it is divided into a left part and a right part which are refracted right and left inversely from each other. When the right and left parts are incident on a synthesizing prism, they are refracted again and travel to be overlapped with each other on a recording medium. The light intensity distribution on a segment at the apex of the synthesizing prism is weaker at the central part and stronger at the peripheral part. This is because the light fluxes resulting from the division are inverted in their position so that the central part of the Gaussian distribution is separated left and right while the peripheral part with a weaker light intensity is centered.

Abstract: In the present invention, a micro Fresnel lens in the shape of a thin film is used. A lens driving member constructed of piezoelectric transducers or of magnets and coils is disposed around the lens. The focus of the lens is adjusted by controlling applied voltages to the piezoelectric transducers or the coils.

Abstract: A film of a crystal - crystal phase transformation type optical recording alloy is formed on an insulating substrate. Information is erased from the alloy film by heating it with an expedient other than a laser beam. Information is read by sensing reflected light of light projected on the alloy film.

Abstract: The present invention provides an optical recording medium using an amorphous-crystalline phase-change for recording and erasing, wherein reflectivity of an optical recording medium-constituting recording film in an amorphous state is larger than that of the optical recording medium-constituting recording film in a crystalline state, or wherein absorptivity of an optical recording medium-constituting recording film in an amorphous state is smaller than that of the optical recording medium-constituting recording film in a crystalline state.