摘要:
Micro-pits or micro-pit strings, which are disabled precise copying by means of illegal copying described above and enable signals different from signals of a normal disc to be detected in case of failure in precise copying, are recorded in a copy protected area of an optical disc beforehand. A read unit checks the copy protected area and determines a loaded disc is legal disc or illegally copied disc. If illegal, reading is prohibitted.
摘要:
An illegal disc copying protection system which includes an optical disc with recorded information as a series of pits aligned to a track direction from the optical disc, a recording system which records information as a series of pits aligned to the track direction from the optical disc, and a reading system which reads information being recorded as a series of pits aligned to the track direction from the optical disc.
摘要:
Micro-pits or micro-pit strings, which are disabled precise copying by means of illegal copying described above and enable signals different from signals of a normal disc to be detected in case of failure in precise copying, are recorded in a copy protected area of an optical disc beforehand. A read unit checks the copy protected area and determines a loaded disc is legal disc or illegally copied disc. If illegal, reading is prohibitted.
摘要:
A meandering groove is formed in a digital disk (10) with a wobble signal that is wobbled to reproduce a clock signal. The wobble signal is read out by an optical head (26). An address detection circuit (40) detects an address signal that is multiplexed with the wobble signal. A PLL oscillation circuit (24) provides a clock signal in synchronization with the wobble signal. Data is modulated by a modulation circuit (16) according to the clock signal and a timing signal based on the address signal, and recorded on the digital disk (10). In reproduction, a RF signal in the wobble signal is converted into a digital signal by an A/D converter (42). The signal is demodulated by a demodulation circuit (44) for data output.
摘要:
An illuminating device (1) is formed of a light source (12) in which LED chips (11) are arranged in an array shape and lens cells (14) are arranged on a light-emission side of each of the LED chips (11), and a pair of fly's eye lenses (13) that integrates and guides to a liquid crystal panel (3) the light emitted from each of the LED chips (11) and collimated by the lens cells (14). The LED chip (11) and the lens cell (14) are formed in a square shape, and an aspect ratio thereof corresponds to that of the liquid crystal display panel (3). In addition, the lens cells (14) are arranged separately from one another in such a manner to have wall surfaces (air gaps), and the wall surfaces serve as reflective surfaces.
摘要:
A table having a plurality of recording densities and a plurality of recording/reproducing conditions corresponding to the recording densities and each necessary for recording/reproducing a signal at a corresponding recording density is recorded in a TOC region of a magneto-optical disk. A recording/reproducing apparatus finds out a recording density at which it can record/reproduce data from the table and records or reproduces a signal at the recording density. The recording/reproducing conditions include the wavelength of a semiconductor laser, whether or not to employ the optical pulse magnetic field modulation recording method, the presence/absence of an optical super resolution pickup, whether or not to employ the optical pulse reproducing method, whether or not to employ the PRML method and the like. Therefore, if the recording/reproducing technology further advances, a signal may be recorded/reproduced to/from the magneto-optical disk at an optimum recording density without having to change the data format of the magneto-optical disk.
摘要:
The present invention is provided with a cartridge holder for installation of a cartridge which houses an optical disk, and a tray which is located below said cartridge holder and in which an unhoused optical disk is placed, and which can move to-and-fro between a position in which information are recorded and/or played back and a position in which the optical disk is exchanged, a center shaft which rotates by means of a rotating drive means, and a holding mechanism including a turntable which is secured to the shaft and is provided with a magnetic body, an optical disk centering means and a support surface which supports the optical disk; and a clamper which can be brought into contact with and separated from the support surface of said turntable and which maintains in contact with the support surface of the turntable optical disks which do not have hubs. The optical information recording/playback device allows installation of a variety of optical information recording media such as optical disk with or without hubs and optical disks which are housed in a cartridge or unhoused.
摘要:
A magneto-optic disk and a recording/reproduction device therefor adopt optical super-resolution to increase recording capacity. More specifically, the magneto-optic disk has an heat emitting layer (6) on a recording layer (4) and still preferably has an intermediate layer (8) between a reproduction layer (3) and the recording layer (4). The recording/reproduction device includes a circuit (33) for pulsing a laser beam to be radiated to the magneto-optic disk and still preferably includes a polarization rotating unit (50) and a polarizing filter (51) for blocking only the center of the laser beam in reproduction. The heat emitting layer (6) diffusing any heat generated by the laser beam, and the discontinuously radiated laser beam allow small recording domain. The laser beam having its center blocked forms smaller main lobe due to diffraction effect.
摘要:
An erasing beam B1 and a recording beam B2 emitted from a laser diode array 20 are focused on different tracks of a optical magnetic disk D, the erasing beam B1 being focused on a track located ahead of a track on which the recording beam B2 is focused. The reflected beams of the erasing beam B1 and the recording beam B2 are separated respectively into two polarized components by means of a polarized beam splitter 17 and the polarized components are received by photo sensor means 23 and 24. Based on outputs of the photo sensor means 23 and 24, an address signal, a focus error signal and a tracking error signal are obtained. At the time of reproduction, the laser diode array 20 emits a reproducing beam so that the photo sensor means provide a reproducing signal.
摘要:
The present invention provides a recording medium and an information recording/reproducing apparatus which permit recording and/or reproducing by a laser beam of optimized power for each recording medium. The recording medium is provided with a calibration region in addition to an information recording region. The calibration region has wobbles formed such that the amplitude of the waveform of a reproduced signal therefrom can change. Prior to recording to the information recording region, a signal is recorded in the calibration region by changing the laser power, and the recorded signal is immediately reproduced. The waveform of the reproduced signal is evaluated to determine optimum laser power for recording. At the time of reproducing, a signal previously recorded in the calibration region is reproduced while changing the laser power, and laser power optimum for reproducing is determined.