Abstract: A difference is set equal to or smaller than 47 nm between first and second birefringent values of a substrate. The first birefringent value is measured for a single pass of an optical beam passing through the substrate of an attitude rotated, relative to a reference plane perpendicular to the optical beam, by 20 degrees around the tangent line tangent to the sequence of phase pits at the projection of the optical beam on the substrate. The second birefringent value is measured for a single pass of the optical beam passing through the substrate of an attitude rotated, relative to the reference plane, by 20 degrees around a straight line extending within a plane including the surface of the substrate in a direction perpendicular to the sequence of phase pits. Jitter can be suppressed in the readout data from phase pits and magnetization in a magnetic film over the phase pits.

Abstract: First and second print layers extend on the surface of a medium body in a recording medium. The first print layer has a first thickness. The second print layer has a second thickness larger than the first thickness. A print protection layer covers over the first and second print layers on the surface of the medium body. An inclined surface is defined on the surface of the print protection layer. The inventors have found that a print layer has various thickness based on the kind of colors. The difference in the thickness causes a step on the surface of the print layer at the boundary between the different colors. The inclined surface is established on the surface of the print protection layer based on the step. A smooth relative movement can thus be realized between a head and the surface of the print protection layer.

Abstract: A magneto-optical recording medium where a magneto-optical recording film is formed on optical phase pits formed on a substrate can be optically regenerated both the optical phase pit signals and the signals of the recording film formed thereon. The magneto-optical recording medium satisfies following condition, 344X?8.12?Y and Y?286X?0.7 0.080?X?0.124 and 16?Y?30 where X (?) is the optical depth of the phase pits formed on the substrate and Y (%) is the modulation degree of the phase pits when irradiated with an optical beam in the polarization direction perpendicular to the tracks of the optical recording medium. According to the above condition, a magneto-optical recording medium, which can suppress the jitter of MO signal and phase pit signal within less than ten percents without generating cracks with a sufficient repeat recording durability, is obtained.

Abstract: The magneto-optical recording medium is comprised of a phase pit substrate/dielectric layer/recording layers/dielectric layer/reflection layer and a ROM and RAM can be simultaneously regenerated. The shape of the phase pit is constructed to be 5<100×Ip/Im<22 where Im is a reflection level on the mirror face and Ip is a phase pit signal output of the shortest mark when a regeneration light having polarization in a direction horizontal to the track direction of the medium is irradiated. Since the jitter of both the magneto-optical recording/regeneration signals and phase pit signals can be suppressed within an optimum range, the quality of the regeneration signals when ROM and RAM are simultaneously regenerated can be improved.

Abstract: A pinion gear is fixed on a rotating shaft of a motor for supplying a driving force of a plurality of driving mechanisms. A speed reducing gear is engaged with the pinion gear, and a sun gear is engaged with a speed reducing gear. A planet worm includes a spur gear portion and a worm gear portion. The spur gear portion is engaged with the sun gear. The planet worm is supported so as to be rotatable around the shaft of the sun gear. When the planet worm is rotated to be positioned adjacent to the cartridge room, the worm gear portion is engaged with a rewind spur gear of a gear train. The rotational force of the motor is transmitted to a rewinding fork through the gear train, and then the rewind fork is rotated.

Abstract: A magneto-optical recording medium where an optical recording film is formed on optical phase pits formed on a substrate can be optically regenerated both the optical phase pit signals and the signals of the recording film formed thereon. The modulation degree of the phase pits is adjusted by changing the gas pressure when the recording film is deposited on the substrate by sputtering. By this, an optical storage medium, of which the jitter of RAM signals and the phase pit signals are suppressed to the target 10% or less, can be uniformly manufactured at low cost.

Abstract: A magneto-optical recording medium including a substrate, a first recording layer provided on the substrate, and a second recording layer provided on the first recording layer. The first recording layer contains Tb and FeCo as principal components and shows a compensation composition or transition metal dominance and perpendicular magnetization at room temperature. The second recording layer has a compensation temperature of not less than 100° C. and shows rare-earth element dominance and perpendicular magnetization at room temperature. The Curie temperatures Tc1 and Tc2 of the first and second recording layers, the coercive forces Hc1 and Hc2 of the first and second recording layers at room temperature, and the thicknesses t1 and t2 of the first and second recording layers satisfy the relations of 60° C.<Tc2<Tc1 and Hc1·t1>Hc2·t2.

Abstract: Provided are a multi-recording medium having recorded thereon mixing information to be used upon synchronously reproducing contents, and a multi-recording reproduction device. An optimum setting is automatically recreated merely by setting the recording medium in the reproduction device. Further, even if the reproduction device is changed, since the mixing information is recorded in the medium, synchronous reproduction can be enjoyed easily without requiring any resetting. Moreover, by using the multi-recording reproduction device, it is possible to change the mixing conditions during synchronous reproduction, or record the changed mixing conditions as new mixing information in a RAM unit. Thereby, the virtual session function and multi-recording function, which were used only by certain professionals, can be realized easily and inexpensively.

Abstract: A magneto-optical recording medium has a substrate having a ROM area with a plurality of phase pits defined therein as providing a ROM signal, and a magneto-optical recording film deposited in an area of said substrate which corresponds to said ROM area, for recording a RAM signal. The phase pits have edges having an average angle of inclination ranging from 10° to 40° at a position in a range of one-half of the depth of each of the phase pits ±20%. Each of said phase pits has a width ranging from 300 nm to 500 nm, and is modulated by a modulation factor ranging from 10% to 30%.

Abstract: Multiple recording and simultaneous regeneration are performed using a storage medium comprising phase pits and a recording layer so that ROM and RAM can be regenerated simultaneously. When data is recorded to RAM while regenerating ROM using the concurrent ROM/RAM recording medium, the start and the end of recording to RAM is controlled using the recording start and recording end signals of the ROM. Therefore the content recording position of the RAM with respect to the content of ROM can be equalized, the delay can be controlled, and the virtual session function and the multiple recording function can be easily implemented at low cost.

Abstract: A worm gear is provided on a rotating shaft of an AF motor. A first supporting cylinder includes a gear portion and a receiving portion. A wheel gear, which is in engagement with the worm gear, is formed on an outer surface of the gear portion. A slit is formed at the receiving portion. A second supporting cylinder includes a supported portion which is placed in the receiving portion of the first supporting cylinder, and a receiving portion which supports an AF coupler. A gear is in engagement with a portion which connects the supported portion and the receiving portion of the 2nd supporting cylinder. A clutch spring is wound around the supported portion, being in contact with the outer surface of the supported portion. Both ends of the clutch spring cross each other and are in engagement with a pair of walls, of the slit, which are parallel to an axis of the receiving portion.

Abstract: An optical recording medium having recording tracks consisting of a plurality of lands and a plurality of grooves, wherein the diameter of a laser beam to be used for recording/reproduction on a recording surface of the medium is 0.7 ?m or less. The optical recording medium includes a transparent substrate on which the lands and the grooves are alternately formed and an optically recordable recording layer provided on the transparent substrate. The width w1 of each land at the center of the height of the boundary between each land and each groove adjacent thereto, the width w2 of a flat top surface of each land, and the depth d of each groove are set to 0.4?w2/w1?0.8 and 25 nm?d?45 nm. At least each land has an edge portion formed as a curved surface.

Abstract: An optical information recording medium can reproduce stably RAM information during concurrent reading out of ROM-RAM information. The optical information recording medium comprises a substrate having a ROM area where phase pits to be ROM data are formed, and a magneto-optical recording film for recording RAM data, formed on an area corresponding to the ROM area of the substrate and, in the ROM area, the degree of modulation in the user area is at least 10-37% and, preferably, the degree of modulation of the phase pits in the user area is 15-25%. As an aspect, the optical depth of the phase pits is approximately ?/8-?/10 (? is the wavelength of the laser used for recording/reproducing).

Abstract: An optical magnetic recording medium in which reproduction is implemented by transcribing a mark to a reproducing layer based on a magnetic field from a recording layer, includes a reproducing layer, a non-magnetic layer, and a recording layer including a first recording layer and a second recording layer, wherein the reproducing layer, the non-magnetic layer, and the recording layer including the first recording layer and the a second recording layer are stacked in this sequence; the regenerating layer has a property of an easy magnetization in an in-plane direction at room temperature; the first recording layer and the second recording layer each has a property of easy magnetization in a vertical direction to the in-plane direction at room temperature in a single layer; and there is a relation of M2<M1 wherein a composition of a rare-earth metal comprising the first recording layer is defined as M1 (at %) and a composition of a rare-earth metal comprising the second recording layer is defined as M2 (at %

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 magneto-optical recording medium including a magnetic recording layer for recording information and a magnetic reproducing layer provided on the magnetic recording layer for reading information. The magnetic reproducing layer is separated into a first reproducing layer having a first composition and a second reproducing layer having a second composition slightly different from the first composition. The first and second reproducing layers have the same principal components. By changing a ratio in film thickness between the first and second reproducing layers, variations in composition of the first and second reproducing layers can be corrected.

Abstract: A pinion gear is fixed on a rotating shaft of a motor for supplying a driving force of a plurality of driving mechanisms. A speed reducing gear is engaged with the pinion gear, and a sun gear is engaged with a speed reducing gear. A planet worm includes a spur gear portion and a worm gear portion. The spur gear portion is engaged with the sun gear. The planet worm is supported so as to be rotatable around the shaft of the sun gear. When the planet worm is rotated to be positioned adjacent to the cartridge room, the worm gear portion is engaged with a rewind spur gear of a gear train. The rotational force of the motor is transmitted to a rewinding fork through the gear train, and then the rewind fork is rotated.

Abstract: A first motor is provided adjacent to a spool. The rotational force of the first motor can be transmitted to the spool through a gear train and can be transmitted to an up-down operating mechanism of the flash case through a cam gear. The change of the transmission path of the rotational force of the first motor is performed by a first change mechanism. The transmitting mechanism including the first change mechanism is provided at the upper side of the spool. A second motor is provide adjacent to a bottom of a cartridge room. The rotational force of the second motor can be transmitted to a rewind fork in the cartridge room, and can be transmitted to a driving mechanism of a quick return mirror, a diaphragm, and a shutter. The change of the transmission path of the rotational force of the second motor is performed by a second change mechanism.

Abstract: A recording medium including a resin substrate having a first thermal expansion coefficient, a center hole, a first surface, and a second surface opposite to the first surface, a recording layer formed on the first surface of the resin substrate and having a recording region, an inner nonrecording region formed inside the inner periphery of the recording region, and an outer nonrecording region formed outside the outer periphery of the recording region, and a protective layer formed on the second surface of the resin substrate except an inner peripheral region having a predetermined range from the center hole, the recording region, and the outer nonrecording region. The thermal deformation suppressing layer has a second thermal expansion coefficient smaller than the first thermal expansion coefficient.

Abstract: A magneto-optical recording medium includes a magnetic reproducing layer having an axis of easy magnetization in a direction perpendicular to its layer surface, a magnetic intermediate layer formed on the magnetic reproducing layer and having an axis of easy magnetization in a plane at a room temperature, and a magnetic recording layer formed on the magnetic intermediate layer and having an axis of easy magnetization in a direction perpendicular to its layer surface. The magnetic reproducing layer has a composition of GdxFeCoy where 22 at %≦x≦25 at % and 16 at %≦y≦23 at %.