Abstract: A verifying device includes a receiving unit operable to receive data recorded on a recording medium and a verifying unit operable to verify the received data. The verifying unit sets a predetermined first range and a second range that includes a plurality of the first ranges on the received data, performs first verification about an error on data included in the first range out of the received data, performs second verification about an error on data included in the second range out of the received data on the basis of a result of the first verification, and determines whether the recorded data is successfully recorded on the recording medium on the basis of the results of the first and second verification.

Abstract: A data recording apparatus includes an acquisition unit configured to acquire a first type data and a second type data, and a recording unit configured to record the first type data or the second type data acquired by the acquisition unit in a recording medium. The recording unit refers to a first pointer which indicates a logical position regarding the first type data in the recording medium to determine a position to start recording the first type data based on the logical position indicated by the first pointer. The recording unit refers to a second pointer which indicates a logical position regarding the second type data in the recording medium to determine a position to start recording the second type data based on the logical position indicated by the second pointer.

Abstract: A data recording apparatus includes an acquisition unit configured to acquire a first type data and a second type data, and a recording unit configured to record the first type data or the second type data acquired by the acquisition unit in a recording medium. The recording unit refers to a first pointer which indicates a logical position regarding the first type data in the recording medium to determine a position to start recording the first type data based on the logical position indicated by the first pointer. The recording unit refers to a second pointer which indicates a logical position regarding the second type data in the recording medium to determine a position to start recording the second type data based on the logical position indicated by the second pointer.

Abstract: An object of the invention is to provide a disc autochanger without any disc reversing mechanism by using on A-side recording and reproducing apparatus and a B-side recording and reproducing apparatus while using a sheet-like optical disc in which both surfaces can be recorded and reproduced. The disc autochanger is constituted by a cartridge storing a plurality of sheet-like optical discs in which both surfaces are recorded and reproduced in a state of putting in a tray, the A-side recording and reproducing apparatus in which a moving table of an A-side recording and reproducing portion is arranged in an upper side of a tray take-out mechanism and a moving table of a cap is provided in a lower side thereof, and the B-side recording and reproducing apparatus in which a moving table of a B-side recording and reproducing portion is arranged in a lower side of the tray take-out mechanism and a moving table of a cap is provided in an upper side thereof.

Abstract: In an apparatus for recording and reproducing a thin optical disc by using the same optical system as that of a CD, a DVD or the like, the invention provides a technique which can stably rotate the thin optical disc at a high speed. The structure can be made such that a turbulence of an airflow is not generated even if the thin optical disc on a turn table is rotated at a high speed, by employing a transparent turn table and arranging a recording and reproducing head or the like in an opposite side to a thin optical disc mounting surface of the turn table.

Abstract: An object of the invention to provide a disc autochanger without any disc reversing mechanism by using on A-side recording and reproducing apparatus and a B-side recording and reproducing apparatus while using a sheet-like optical disc in which both surfaces can be recorded and reproduced. The disc autochanger is constituted by a cartridge storing a plurality of sheet-like optical discs in which both surfaces are recorded and reproduced in a state of putting in a tray, the A-side recording and reproducing apparatus in which a moving table of an A-side recording and reproducing portion is arranged in an upper side of a tray take-out mechanism and a moving table of a cap is provided in a lower side thereof, and the B-side recording and reproducing apparatus in which a moving table of a B-side recording and reproducing portion is arranged in a lower side of the tray take-out mechanism and a moving table of a cap is provided in an upper side thereof.

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: In an apparatus for recording and reproducing a thin optical disc by using the same optical system as that of a CD, a DVD or the like, the invention provides a technique which can stably rotate the thin optical disc at a high speed. The structure can be made such that a turbulence of an airflow is not generated even if the thin optical disc on a turn table is rotated at a high speed, by employing a transparent turn table and arranging a recording and reproducing head or the like in an opposite side to a thin optical disc mounting surface of the turn table.

Abstract: An information recording medium and manufacturing method for high-speed and high density recording. An inorganic film is formed by sputtering while applying a bias voltage to shift the substrate voltage potential in the negative direction, or a laminated film is formed by applying energy after coating a substrate with an organic film, and the irregularities maintained even after the laminated film is formed, so that stable, high-capacity and high-speed recording can be attained by forming a multi-information-layer that still retains the irregularities.

Abstract: An information recording and reproducing apparatus that is smaller in size, high in disk exchange speed, loaded with optical disks and large in capacity is provided by providing an information recording and reproducing apparatus comprising a cartridge loaded with optical disks, a head for recording information on and reproducing information from one of the optical disks, a spindle for rotating the optical disk, and a first robot arm for carrying the optical disk between the cartridge and the spindle, the first robot arm being variable in length, the cartridge being expandable and contractible in a direcition perpendicular to the surface of the optical disk.

Abstract: An object of the invention is to provide an extremely large capacity disc cartridge which can avoid a head crush and a disc crush and has a high reliability, and a recording and reproducing apparatus for the same.

Abstract: A magneto-optical recording medium has magneto-optical recording layers (11, 12, 13) and reproducing layers (21, 22, 23). The information recorded in the reproducing layers are reproduced by means of reproducing light beams (31, 32, 33) of different wavelengths, respectively. In reproduction, magnetic domains (4) recorded in the recording layers are transferred in the reproducing layers formed on the respective recording layers, the transferred magnetic domains (5) are enlarged with an external magnetic field, and the information is reproduced. Since information is recorded and reproduced for each recording layer, the recording density is improved. Further since the reproduction signals are amplified by the magnetic domain enlargement, the C/N is improved.

Abstract: A magnetic recording medium comprises an information-recording film and a ferromagnetic film on a substrate. The information-recording film is composed of, for example, an amorphous ferrimagnetic material having perpendicular magnetization. Further, the ferromagnetic film is composed of a magnetic material which has saturation magnetization larger than that of the information-recording film. Accordingly, the leak magnetic flux from the ferromagnetic film is larger than that from the information-recording film. The magnetic recording medium and a magnetic recording apparatus are obtained, which are excellent in thermal stability and which are preferred to perform super high density recording.

Abstract: A magneto-optical recording medium includes a recording layer, a reproducing layer in which information is subjected to expansion reproduction, a first intermediate layer which is provided between the recording layer and the reproducing layer, a recording magnetic field assist layer which is provided on a side opposite to a side of the first intermediate layer with respect to the recording layer, and a second intermediate layer which is provided between the recording layer and the recording magnetic field assist layer. The recording magnetic field assist layer exhibits perpendicular magnetization, which is one of an amorphous alloy film containing GdFeCo as major component and a multilayer film formed by alternately stacking transition metal layers and noble metal layers. The recording magnetic field assist layer generates the assist magnetic field during recording of information to form stable recording magnetic domains even when the external magnetic field is low.

Abstract: A means is provided to determine, accurately in a shorter period of time, an optimum reproducing laser beam intensity for reproducing user data or various management data on a magneto-optical recording medium based on the magnetic amplifying magneto-optical transfer system. In a method for determining the reproducing laser beam intensity of the present invention, a test reproduction area, which is formed of maze magnetic domains having random sizes not subjected to any recording process and provided on a magneto-optical recording medium based on Zero-Field MAMMOS, is irradiated with a laser beam before reproducing user information while changing the laser beam intensity to detect a magneto-optical signal. Subsequently, the reproducing laser beam intensity is determined for user information on the basis of the magneto-optical signal obtained from the test reproduction area.

Abstract: A magneto-optical recording medium which includes a reproducing layer. When a laser beam is irradiated to the magneto-optical recording medium, a magnetic domain in a recording layer is transferred, through enlargement, to a reproducing layer increased in temperature. The magneto-optical recording medium further includes a calibration area that has a calibration magnetic domain recorded in a predetermined pattern in the recording layer. In a reproducing apparatus, a laser beam of an optical head is adjusted in output depending upon a reproduced signal obtained by reproducing the calibration magnetic domain.

Abstract: A magneto-optical recording head comprises a magnetic coil formed on a lower surface of a transparent substrate opposed to a magneto-optical disk. A heat sink layer is provided at the outside of the magnetic coil on the lower surface. An objective lens is supported on an upper surface of the transparent substrate. The heat, which is generated by the magnetic coil, is released via the heat sink layer to the space between the magneto-optical disk and the substrate. The release of the heat is facilitated by the air stream which is generated by the rotation of the magneto-optical disk. The heat can be effectively released from the magnetic coil without inhibiting optical characteristics of the objective lens.

Abstract: A magneto-optical recording medium wherein a magnetic domain is transferred from a recording layer to a reproducing layer is expanded. When the reproducing layer is formed, the composition ratio of a transition metal at a surface of the reproducing layer on a reproducing light beam-incoming side is made to be higher than the composition ratio of the transition metal at a surface of the reproducing layer on a side opposite to the reproducing light beam-incoming side. Thus, the operation to expand the magnetic domain, transferred from the recording layer to the reproducing layer, is performed smoothly, and the jitter of the reproduced signal is reduced to improve signal-to-noise ratio (S/N) of the reproduced signal.

Abstract: A magneto-optical recording head comprises a magnetic coil formed on a lower surface of a transparent substrate opposed to a magneto-optical disk. A heat sink layer is provided at the outside of the magnetic coil on the lower surface. An objective lens is supported on an upper surface of the transparent substrate. The heat, which is generated by the magnetic coil, is released via the heat sink layer to the space between the magneto-optical disk and the substrate. The release of the heat is facilitated by the air stream which is generated by the rotation of the magneto-optical disk. The heat can be effectively released from the magnetic coil without inhibiting optical characteristics of the objective lens.

Abstract: A magneto-optical recording medium comprises a recording layer 5, an intermediate layer 4, and a reproducing layer 3. The reproducing layer 3 is formed of a rare earth transition metal alloy in which rare earth metal is dominant, and each of the intermediate layer 4 and the recording layer 5 is formed of a rare earth transition metal alloy in which transition metal is dominant. The intermediate layer 4 exhibits in-plane magnetization at a temperature of not less than 140° C. Therefore, the intermediate layer 4 cuts off the exchange coupling force between the recording layer 5 and the reproducing layer 3 during the reproduction. A magnetic domain 3A, which is transferred to the reproducing layer 3, is expanded to a size of a minimum magnetic domain diameter by the magnetostatic repulsive force exerted between the magnetic domain in the intermediate layer 4 and the magnetic domain in the reproducing layer.