Abstract:
An optical record carrier comprises substantially parallel tracks being divided into recording units having an address area (23, 24), adjacent address areas of adjacent tracks (43, 44) comprising shared address marks (48). Shared address marks (47, 48) are positioned in between adjacent tracks and arranged in sharing portions (40, 41) of the address area, each sharing portion sharing address marks only to one side. The address area also comprises a free portion (39) which is free from shared address marks, which free portion is aligned with a sharing portion (42) of an adjacent address area. This is advantageous for reducing crosstalk in the address read signal. The sequence of the free and sharing portions within an address area differs so as to be matching in adjacent address areas. Further an apparatus for scanning the record carrier is described, which apparatus comprises an optical system (52) for generating a spot (66) on the record carrier via a radiation beam (65), tracking means (51), address recovery means (50, 56) and positioning means (54) for moving the spot to a desired track. The address recovery means (50, 56) are arranged for detecting the free portion and deriving the sequence of the free and sharing portions.
Abstract:
The tracks in a read-only area are divided into sector regions having the same capacity, error correcting codes are added to 1st data signals to generate 2nd data signals and pit rows are formed in the sector regions to record data. In a rewritable area, recorded user data are correlated with 1st data, the same error correction codes used for the read-only area are added to the 1st data signals to generate 2nd data signals in a similar way and data signals for making rewritable are added to the 2nd data signals to generate 3rd data signals. A format is set up by adding a header region where sector address information is recorded to a region in which the 3rd data signals are recorded. The region is divided into two areas radially, the outer area being made a rewritable area and the inner area being made a read-only area. Control data signals are recorded in the read-only area.
Abstract:
A magneto-optical recording medium (11) has a second auxiliary magnetic film (4), a first auxiliary magnetic film (5) and a magneto-optical recording film (6) in this order from the laser beam applied side. If the temperatures of the first and second auxiliary magnetic films (4 and 5) exceed their critical temperatures TCR1 and TCR2, the magnetization of the auxiliary magnetic films is changed from the surface magnetization to the vertical magnetization. The Curie points TC0, TC1 and TC2 of the magneto-optical recording film (6), the first auxiliary magnetic film (4) and the second auxiliary magnetic film (5) and the critical temperatures TCR1 and TCR2 satisfy the relations room temperature
Abstract:
Address blocks (16, 17, 18 and 19) where identifiable information including address numbers (13) and redundant order numbers (14) is recorded are provided in a selector address area (5), and are grouped in pairs. The address groups are staggered with radial pitches of about a half track pitch along the center line of the track (2).
Abstract:
An optical storage system including an optical storage means (25) for holographic storage of data and an optical head (24). One embodiment of the optical storage means is a card the size and shape of a normal credit card. The optical head and associated control means may be embodied in a optical drive the size of standard disk drives. The system is able to write, read and erase data. The storage means (25) can store terabytes of information. The optical head (24) is an integrated optical element without moving parts.
Abstract:
An optical record carrier (RC and RC'), and methods and apparatuses for recording and reproducing an information on and from said optical recording carrier (RC and RC'), whereby the effects of crosstalk from adjacent tracks (TR) is reduced, and stable tracing control is possible, is achieved. A recording track (TR) to which information (Sm) divided into sector units (S) is recorded is formed in a spiral or concentric pattern on the surface of the optical record carrier (RC and RC'). Each sector further comprises sixty frames (FRf). Each frame (FR) comprises a re-sync pattern (RS), frame address (FA), data (INF), and postamble (PA) fields. Identification information (SA) indentifying the sector location of the information (INF) is recorded to the data block of the first frame (FR1). The user data (UDf) is recorded after the data (INF) is scrambled using a value (SR) generated by a fifteen-stage maximum-length sequence generator (603) based on the value of this identification information (SA). The correlation between signals on adjacent tracks (TR) is thus reduced, and the effects of crosstalk are randomized, thus reducing the effect on the track error signal and enabling extremely stable tracking control.
Abstract:
In the portions of a program region and a recording region which are in a boundary between these two regions, buffering regions in which effective data do not exist are provided. These buffering regions are determined as access inhibited regions, to/from which neither recording nor reproduction is carried out. Accordingly, the oscillation of a tracking servo which is liable to occur when an optical spot passes the boundary between the program region and recording region is minimized. This enables a constantly stable operation of the tracking servo to be attained, and the temporary omission of information signals to be prevented.
Abstract:
An optical disk having a plurality of substantially concentric tracks, each of which includes a plurality of segments each comprising a servo area ARs provided with servo pits for giving servo information to a disk drive and a data area ARd. Identification marks SGM, ADM, STM1, STM2 are recorded in the servo area ARs. The identification marks SGM, ADM, STM1, STM2 provide information for identifying the respective segments depending on the recording position in the servo area ARs.
Abstract:
This invention provides a copy-protected optical disk (9), a reproduction apparatus (47) of the optical disk, a reproduction method of the optical disk, a production method of an original disk of the optical disk and a method of preventing an illegal program operation. An area in which a CP signal (24) having the center of an eye pattern deviated from the center of an amplitude is recorded is disposed at the back of a predetermined pattern signal in the optical disk. A reproduction apparatus additionally has the function of detecting an arrangement information (25) of the CP signal or a CP preceding signal (26), applying an offset voltage to a threshold value at the time of demodulation of an RF signal to a digital signal to change the threshold value, normally reproducing the signal having the center of the eye pattern deviated from the center of the amplitude, and stopping reproduction when a predetermined offset signal is not reproduced.
Abstract:
A recordable optical disc capable of optically recording the data. The disc has, as a pre-pit, a pit (4a) of a rugged pattern that corresponds to a synchronized signal portion recorded on the reproduction-only optical disc in the form of pits of rugged pattern. The region sandwiched by the pre-pits (4a) serves as a region for recording data (6a) supplementarily. Therefore, the recordable optical disc can be reproduced using a player for reproduction-only optical disc, enabling the two discs to be interchangeable.