Abstract: The present invention provides a time setting system and method thereof that are capable of correctly setting time if a delay occurs in the transmission of time information. In the system for setting a master time outputted from a master apparatus to a slave time of a slave apparatus that counts time independently of the master apparatus, the slave apparatus has transmission section for transmitting master time request information to the master apparatus via a network and the master apparatus has an allowable range information acquisition section for acquiring allowable range information indicative of an allowable time in which the master time may be set to the slave time of the slave apparatus and transmission section for transmitting the master time and allowable range information to the slave apparatus.

Abstract: A copyright management system that manages the time limits of the reproduction of a plurality of pieces of content in a batch manner. A content reproduction apparatus has a storage unit storing a reproduction permission ID list and the valid period information of each group ID and a reproduction control block for controlling the reproduction of content data attached with the group ID. The reproduction control block reads the group ID from content data and, if the read group ID is contained in the reproduction permission ID list and the current time is not in excess of the valid period of this group ID, permits the reproduction of the content data; if the read group ID is not contained in the reproduction permission ID list or the current time is in excess of the valid period of this group ID, the reproduction control block restricts the reproduction of the content data.

Abstract: The present invention is a magneto-optical disk adopting the magnetic domain wall displacement detection type ultra-high resolution playback method. The magneto-optical disk has a recording track whose width Tw given as Tw≦0.046×(&lgr;/NA), where &lgr; is a wavelength of a laser light which is irradiated to a magneto-optical disk to play back recorded signals recorded on the magneto-optical disk and NA is a numerical aperture. Thus, the detrack tolerance can be 160 nmpp or more, which is contributed to easier design of the disk drive tracking.

Abstract: A device and a method can judge the radial moving direction of light spots formed on the signal recording surface of an optical disc having grooves of two types that are different from each other in terms of depth and arranged along a recording track that is a land of the optical disc. The judging section of the device judges the moving direction of the main spot on the basis of binarized data of a difference signal of the main spot and binarized data of a difference signal of one of the side spots. With this arrangement, the moving direction of the light spots relative to a radial direction of the optical disc can be determined only by using difference signals without using any sum signal.

Abstract: An information recording/reproducing apparatus for recording and reproducing information to and from a magneto-optical storage medium that includes a first magnetic layer for recording at least information, a second magnetic layer for regulating a switched connective force, and a third magnetic layer for shifting a magnetic wall of recorded markings for information reproduction. The three layers being stacked on a transparent substrate to make up the storage medium. The information recording/reproducing apparatus includes an optical head and a magnetic head. The optical head has a light source and an objective lens, the light source is configured to emit at least a laser beam with a wavelength of about 780 nm, the objective lens having a numerical aperture of about 0.45 and is configured to focus the laser beam from the light source into a beam spot for emission onto the magneto-optical storage medium. The magnetic head is for applying a recording magnetic field to the magneto-optical storage medium.

Abstract: A laser beam for reproduction emitted from an LD (41) at the time of reproduction passes through an As correction board (42) and a grating (43) and becomes incident on a beam splitter (44). The beam splitter (44) transmits the laser beam and causes the laser beam to be incident on a liquid crystal unit (45). Then, at the time of reproduction, a light spot shaping device provides aberration to the laser beam transmitted through the liquid crystal unit (45) in accordance with the type of a magneto-optical disc and thus shapes a light spot on the magneto-optical disc. Therefore, optimum light spots for different media can be shaped.

Abstract: A recording and/or reproducing method for using an optical disc in the recording or reproduction data on or from the optical disc in predetermined data-length units. In a recording operation, the recording and/or reproducing method includes the step of dividing data read from the optical disc in the predetermined sector length, rewriting inputted data into the desired sector which is divided from the predetermined data-length inputs and recording the data including the rewritten sector on the optical disc in the predetermined data-length units. In a reproducing operation, the recording and/or reproducing method includes the step of reading the data having from the optical disc in the predetermined data-length units, dividing the data read from the optical disc in the predetermined data-length units into the predetermined sector length and transferring data of the reproduced desired sector as output data.

Abstract: A recording/reproducing apparatus for an optical recording card is disclosed, which comprises an optical recording card (10) provided with an optical recording medium (11), a recording light source (5) for recording an information signal on the recording medium (11), a reproduction light source (1) for reproducing the information signal recorded on the recording medium (11) and a line sensor (15) for reading out the information recorded on the recording medium (11) from the light beam reflected from the recording medium (11). A light path of a light beam emitted from the recording light source (5), a light path of a light beam emitted from the reproduction light source (1), and a light path of the light beam reflected by the recording medium (11) are independent of one another.

Abstract: A ferrite for magnetostrictrive vibrators is produced by the simple process of press forming a preformed structure formed from starting powder of magnetite or a mixture of magnetite and ferric oxide, said powder having an average particle size d (.mu.) of from 0.02 to 5.0 .mu., sintering this structure in an atmosphere wherein the partial pressure of oxygen is from 10.sup.-1 to 10.sup.-11 atmosphere at a temperature of from 1,000.degree. to 1,350.degree. C. and which will meet the requirement:140 log d+1,305.gtoreq.T(.degree.C.).gtoreq.160 log d+1,180and thereafter cooling the structure thus sintered to room temperature at a cooling rate m (.degree.C./min.) <0.5f where f(KHz) is a corresponding resonance frequency thereby to produce a macroscopically homogeneous ferrite structure containing as its principal constituent a sintered magnetite having an oxygen/iron (O/Fe) atomic ratio of 4.0/3<0/Fe<4.1/3, and a density of at least 90% of the theoretical density.

Abstract: A method for generating magnetostrictive vibration which comprises:Providing a vibrator element comprising a sintered structure of magnetite having an oxygen/iron (O/Fe) atomic ratio within the range of 4.0/3 to 4.1/3, a specific resistance of not lower than 0.1 ohm cm, and a positive static magnetostriction and containing in its sintered state at least one additive element selected from the group consisting of cobalt, calcium, titanium, silicon, boron, and sodium; andApplying an alternative magnetic field to the vibrator element.There is also provided an improved magnetostrictive vibrator element for use in the above method, which comprises:The above-mentioned sintered structure, andFixing means for applying a compressing force of 30 to 1800 Kg/cm.sup.2 to opposite ends of the sintered structure in the direction of the principal vibration thereof.