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:
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:
A magneto-optical record medium and a reproducing apparatus for the same allow data reproduction having good characteristics by a simple structure. The magneto-optical record medium includes a plurality of first grooves (3) each having sidewalls, at least one of which is wobbled in accordance with address information; an address mark (21) formed by changing a width of a land located between second grooves connected to the first grooves; and third grooves wobbled cyclically, formed in a data portion magnetically storing data and connected to the second grooves. The reproducing apparatus reproduces the data from the magneto-optical record medium.
摘要:
An magneto-optical disc recording/reproducing apparatus includes an optical head (36) to detect a wobble (46) and an address mark (81 to 84) in an magneto-optical disc (31) and output a wobble signal (WB1, WB2) and an address mark signal (AML, AMG), a PLL circuit (47) to generate a clock signal (CK) in response to wobble signal (WB1), an address mark synchronous signal generation circuit (46) to generate an address mark synchronous signal (AM) in response to address mark signal (AML, AMG), a synchronizing circuit (48) to synchronize clock signal (CK) with address mark synchronous signal (AM) and generate a synchronized clock signal (SCK), and a timing setting circuit (49) to generate a timing pulse signal (TG1) to control a magnetic head driving circuit (34) and a timing pulse signal (TG2) to control a laser driving circuit (35). The recording/reproducing apparatus can detect a address mark (81 to 84), record la data signal on magneto-optical disc (31) in synchronization with the detected address mark, and reproduce a data signal from magneto-optical disc (31) in synchronization with the detected address mark, so that the data signal can be surely recorded/reproduced.
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 optical disc and an optical disc drive for the optical disc are provided which are suitable for recording data with a high density. The optical disc D uses both lands and grooves as recording tracks. Each of the tracks consists of one address segment and forty five data segments. The address segment is wobbled at one side thereof. Each of the data segments is a DC groove. The address segment records an address information including a sync signal, frame address, track address and CRC, a tilt pattern and a clock mark. The clock mark is adapted to reflect laser beam in one amount before the mark and in another amount after the mark. The tilt pattern has a different track pitch from those in other areas. The data segments record data magneto-optically.
摘要:
A memory card (110) stores access restriction information (AC1) to a license information hold unit (1440) arranged in a TRM area. Access restriction information (AC1) has information for example of a frequency of reproduction allowed and a number of licenses owned. A controller (1420) in reproducing and transferring content initially confirms access restriction information (AC1) and thereafter effects reproduction and transfer and after the reproduction and transfer are effected updates access restriction information (AC1), as required, for storage in a license information hold unit (1440).
摘要:
A cellular phone has distributed encrypted content data and an encrypted content key stored in a memory. The encrypted content key data read out from the memory is decrypted by a decryption processing unit using key data Kp stored in a Kp hold unit, and then applied to a audio reproduction module. A decryption processing unit decrypts encrypted content data read out from the memory using a content key Kc extracted by the decryption processing unit to reproduce content data Dc.
摘要:
In a cellular phone, a controller stores content data received from a distribution server into a memory. When the content data is to be transmitted to a memory card, a random number key generator generates a license key, and an encryption processing unit encrypts the content data using the license key. The controller transmits encrypted content data to a memory card via a memory card interface. Then, the controller deletes the content data stored in the memory. As a result, distribution of content data that must be deleted when transferring to another apparatus can be facilitated while protecting the copyright.
摘要:
A memory card 110 extracts a session key Ks from the data applied onto a data bus BS3 by carrying out a decryption process. An encryption processing unit 1406 encrypts a public encryption key KPcard(1) of memory card 110 based on session key Ks, and applies the encrypted key to a server via data bus BS3. A memory 1412 receives from a server data such as license key Kc, license ID data License-ID and user ID data User-ID encrypted with a public encryption key KPcard(1) differing for each memory card for storage, and receives encrypted content data [Dc]Kc encrypted with license key Kc from data bus BS3 for storage.