Abstract: An optical memory element includes a guide track groove portion and address signal pit portion for indicating the address of the guide track groove. The address signal pit portion has a pit width narrower than the groove width of the guide track groove portion.

Abstract: An optical memory element includes a guide track groove portion and address signal pit portion for indicating the address of the guide track groove. The address signal pit portion has a pit width narrower than the groove width of the guide track groove portion.

Abstract: A method is provided for manufacturing a magneto-optical memory element having guide grooves for storing information. The method includes applying a laser beam onto a resist film material located on a substrate to produce guide track grooves and address signal pits. Thereafter the resist film is developed. The remaining resist film is removed and a magnetic medium layer is deposited on the substrate.

Abstract: In an optical memory medium comprising prepits on which a light spot is impinged to obtain information and, if required, guide grooves: each of those among the prepits which are longer than the diameter of the light spot consists of a series of pit portions and unpitted portions; each of the prepits is sandwiched between two of the discontinuous portions of guide grooves adjacent to each other; the guide grooves have one or more narrow portions, and each of the prepits is sandwiched between two of the narrow portions of guide grooves adjacent to each other; or the guide grooves have one or more long portions, one or more short portions, and narrow portions formed between the long and short portions, and each of the prepits is sandwiched between two of the short portions of guide grooves adjacent to each other.

Abstract: An optical memory disc medium contains a plurality of guide groove tracks. The guide groove tracks are arranged parallel to each other and they are used for controlling a position of a light beam. There is a land region between the guide groove tracks which is wider than the width of the guide groove tracks as measured in the disc-radial direction. Prepits for providing address information for the guide groove tracks are provided. The prepits are formed on the land regions and interposed between the lateral edges in the disc-radial direction of adjacent parallel guide groove tracks. Each prepit has a width which width is a narrower dimension than the width of each guide groove track as measured in the disc-radial direction.

Abstract: Provided is a lithium secondary battery excellent in initial charge/discharge characteristics and high in capacity comprising lithium-rechargeable cathode and anode and a nonaqueous electrolyte, wherein at least one of the cathode and the anode contains one of the following (A), (B) and (C):(A) a composite material comprising a carbon powder and a binder, which is treated with a silane coupling agent,(B) a composite material comprising a binder and a mixed carbon powder containing 70-99% by weight of a graphite powder and 30-1% by weight of a pseudo-graphitic carbon black, and(C) a composite material comprising a composite oxide powder of lithium and a transition metal, a conductive powder and a binder, which is treated with a silane coupling agent.

Abstract: A magneto-optical memory apparatus for enhancing the recording density of a magneto-optical recording medium, thereby to increase its recording capacity. The magneto-optical recording medium having recording marks, each having two ends in which information is recorded.

Abstract: In an optical memory medium comprising prepits on which a light spot is impinged to obtain information and, if required, guide grooves: each of those among the prepits which are longer than the diameter of the light spot consists of a series of pit portions and unpitted portions; each of the prepits is sandwiched between two of the discontinuous portions of guide grooves adjacent to each other; the guide grooves have one or more narrow portions, and each of the prepits is sandwiched between two of the narrow portions of guide grooves adjacent to each other; or the guide grooves have one or more long portions, one or more short portions, and narrow portions formed between the long and short portions, and each of the prepits is sandwiched between two of the short portions of guide grooves adjacent to each other.

Abstract: A method for manufacturing an optical memory element including the steps of disposing a resist film on a substrate, placing a photo-mask carrying a guide groove pattern on the resist film so as to position the photo-mask over a predetermined position of the substrate, forming a guide groove pattern latent image on the resist film, developing the guide groove pattern latent image formed on the resist film, conducting an etching operation through the developed guide groove pattern as to form guide grooves in the substrate, removing the resist film from the substrate, and disposing a recording medium layer on the substrate having the guide grooves formed therein.

Abstract: A recording and reproducing device, which records and reproduces information on and from a rewritable recording medium having absolute addresses and including an information recording area wherein information entered from external devices is recorded and a Table of Contents area wherein additional address information with respect to the information recorded in the information recording area is recorded. The TOC area contains the absolute addresses of the recording positions of each information recorded in the information recording area. A display section graphically and independently displays the recorded and unrecorded ranges of the information recording area according to the absolute addresses recorded in the TOC area with respect to the recording positions of each piece of information.

Abstract: A disk recording and reproducing device records and reproduces information on and from a magneto-optical disk having 3 3 and there is TOC (Table of Contents) area. Additional information with respect to each piece of the information recorded in the information recording area is recorded in the TOC. The device includes operation keys, a TOC memory for storing read/write control information for desired pieces of information entered through the operation keys. There is an optical head and a magnetic coil for recording, in the TOC area, the contents stored in the TOC memory as additional information. A controller controls the read/write operation to the disk according to the read/write control information. With the arrangement, a user can recognize necessary/unnecessary information and defective parts in the disk, and therefore make effective use thereof as well as maintaining secrecy of the information.

Abstract: A tracking system for positioning a light spot onto a magneto optic or optical disc having a beam guide track preformatted thereon comprises a main light beam and two auxiliary light beams, and a circuit for subtracting a low frequency component of a difference between the tracking error signals, detected by the respective auxiliary light beams and the main light beam, from a tracking error signal detected by the main light beam.

Abstract: An information recording and reproducing device records, erases and reproduces information on and from a memory device. The memory device has pre-format sections. The information recording and reproducing device includes a pre-recorded area detection circuit for detecting a pre-recorded area having information predeterminately recorded and located on the memory device and timing control circuits for providing timing control of an information recording, erasing or reproducing operation according to a pre-recorded area detecting signal released from the pre-recorded area detection circuit, thereby enabling each timing of recording, reproducing, or erasing operation is accurately determined. The timing control may be performed according to both of the pre-recorded area detecting signal of the present invention and the conventional synchronization detection signal.

Abstract: An information recording and reproducing device having an automatic gain control device wherein its amplification degree is adjusted according to an AGC voltage varying with an amplitude of a reproduced signal. The automatic gain control device has a holding circuit which holds the AGC voltage in each of recording and erasing operations, and also holds the AGC voltage in reproducing an un-recorded area of information. The AGC voltage is also used for determining an optimum recording condition for a recording medium. Instead of the holding circuit, by installing a limiter circuit for limiting an amplitude of a reproduced signal, and by the use of transient response of the reproduced signal due to an coupling situated before the limiter circuit, an appropriate amplification degree can also be obtained in the automatic gain control device.

Abstract: An optical memory device comprising a substrate and guide tracks having a depth of .lambda./8n or less formed on said substrate, wherein .lambda. is the wavelength of laser light used for the optical memory device, and n is the refraction index of the guide track portion of the substrate.

Abstract: In the optical recording element of the invention, alignments of long thin pits inclined in various directions with respect to the track direction are formed on the tracks and information is recorded therein according to the different inclines of the pits, thereby performing higher-density and larger-volume recording without reducing the spacing between each pit and the track pitch. The invention also discloses an optical data retrieval system for use with the above optical recording element, which scans the pit alignments with a laser beam spot, detects the inclines of the pits by obtaining the distribution of the intensity of reflected light which is caused by light diffraction at the pits, and plays back information in accordance with the inclines. Therefore, not only can the substantially same structure as that of a standard type optical data retrieval system be applied to the invention without making any complicated change, but also cross-talk is less likely to be produced in the read out signals.

Abstract: An optical disk recording and reproducing apparatus in which during coarse access, an adjustable target speed is obtained using a speed offset value stored in a speed offset memory. The speed offset value being determined between a plurality of reference velocities and a plurality of adjustable offset velocity values. The system also performs fine access within a defined distance from the optical head to the designated track upon completion of the coarse access mode. The speed offset values are continually updated by to improve the accuracy of the coarse access operation saving overall access time.

Abstract: An apparatus for recording and reproducing information on and from an optical disk is disclosed in which at least one optical beam and a reference clock signal are used. The optical disk comprises recording tracks which are divided into a plurality of blocks and concentrically arranged along the radial direction. The apparatus comprises: a block judging unit for judging one of the blocks that the one block is currently impinged by the optical beam; a clock signal generator for generating a plurality of clock signals which are different in frequency from each other; and a clock signal selecting unit for selecting one of the clock signals as the reference clock signal, on the basis of the judgement of the block judging unit.

Abstract: A recording and reproducing device, which records and reproduces information on and from a rewritable recording medium having absolute addresses and including an information recording area wherein information entered from external devices is recorded and a Table of Contents area wherein additional address information with respect to the information recorded in the information recording area is recorded. The TOC area contains the absolute addresses of the recording positions of each information recorded in the information recording area. A display section graphically and independently displays the recorded and unrecorded ranges of the information recording area according to the absolute addresses recorded in the TOC area with respect to the recording positions of each piece of information.

Abstract: In the optical recording element of the invention, alignments of long thin pits inclined in various directions with respect to the track direction are formed on the tracks and information is recorded therein according to the different inclines of the pits, thereby performing higher-density and larger-volume recording without reducing the spacing between each pit and the track pitch. The invention also discloses an optical data retrieval system for use with the above optical recording element, which scans the pit alignments with a laser beam spot, detects the inclines of the pits by obtaining the distribution of the intensity of reflected light which is caused by light diffraction at the pits, and plays back information in accordance with the inclines. Therefore, not only can the substantially same structure as that of a standard type optical data retrieval system be applied to the invention without making any complicated change, but also cross-talk is less likely to be produced in the read out signals.