摘要:
A record carrier has substantially parallel tracks, which exhibit first variations of a first physical parameter and second variations of a second physical parameter of the track. The first variations represent information recorded on the record carrier, which information is recoverable by means of a controllable type of data processing. A modulation pattern of the second variations represents a code for controlling the type of data processing. With respect to a code track that includes the modulation pattern, the modulation pattern in the left neighboring track is aligned to the modulation pattern in the right neighboring track. Thereby crosstalk due to the second variations in decreased, and at least two tracks have the same modulation pattern. The playback device has a demodulator and a control unit for retrieving the code from at least two tracks.
摘要:
A record carrier has substantially parallel tracks having first variations of a first physical parameter and second variations of a second physical parameter of the track. The first variations represent information recorded on the record carrier, this information being recoverable by a controllable type of data processing. A modulation pattern of the second variations represents a code for controlling the type of data processing. In respect of a code track that includes the modulation pattern, the modulation pattern in the left neighboring track is aligned to the modulation pattern in the right neighboring track. Thereby crosstalk due to the second variations is decreased, and at least two tracks have the same modulation pattern. The playback device has a demodulator (50) and a control unit (56) for retrieving the code from at least two tracks.
摘要:
A record carrier has substantially parallel tracks having first variations of a first physical parameter and second variations of a second physical parameter of the track. The first variations represent information recorded on the record carrier, this information being recoverable by a controllable type of data processing. A modulation pattern of the second variations represents a code for controlling the type of data processing. In respect of a code track that includes the modulation pattern, the modulation pattern in the left neighboring track is aligned to the modulation pattern in the right neighboring track. Thereby crosstalk due to the second variations is decreased, and at least two tracks have the same modulation pattern. The playback device has a demodulator (50) and a control unit (56) for retrieving the code from at least two tracks.
摘要:
A method and device for recording information signals on a partly recorded writable record carrier (11), e.g., an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which includes preformed track position information indicative of locations for recording the information units. From the information signal, a modulated signal is generated having successive frames, each frame including a synchronizing signal. The modulated signal is recorded at a one of the locations, while maintaining a fixed relationship between the track position information and the synchronizing signals. In the event that the location is after and adjacent to an already recorded location, the recording is started at a link position (31) before the end of a last frame of the earlier recorded information signal, at a predefined distance before a first synchronizing signal (30) of the modulated signal.
摘要:
An optical recording method and recording apparatus using this method is described in which an optimum write power of a radiation beam in the apparatus is set by writing a series of test patterns on an optical recordable medium, forming a read signal from the patterns, reading a preset value of the derivative of the modulation of the read signal with respect to the write power from the medium, and processing the read signal together with the preset value to derive an optimum value of the write power.
摘要:
The invention relates to an optical disc for recording data at a constant density, so called CLV (Constant Linear Velocity) or at zoned CLV. The disc has headers distributed along the disc on regular angular positions, a so called CAV (Constant Angular Velocity) pattern subdividing the track in track portions for recording an amount of data proportional to the radial position of the track portion concerned. Address information included in the headers is provided at the data density, which is CLV. The apparatus comprises header detection means for detecting the headers at the CAV locations, and for recovering position information from the headers at CLV density. Data sectors do not start at headers and are not fitted regularly between the headers, but start and stop at arbitrary positions which are calculated from the known amounts of data recordable in the track portions.
摘要:
A record carrier is described comprising a servo track indicating an information track intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track has a periodic variation of a physical parameter. The periodic variation is modulated for encoding record carrier information, such as addresses. The modulation is a bi-phase modulation in which a data bit of the record carrier information is encoded by a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase. A recording and/or playback device has a demodulator for retrieving data bits of the record carrier information from a first predetermined number of variations of a first phase followed by the same number of variations of a second phase inverse to the first phase.
摘要:
An optical record carrier has parallel tracks for recording user information in a pattern of optically detectable marks, the tracks being provided with control information. The tracks are grouped in pairs of neighboring tracks. The control information in both tracks of a pair is identical and the control information in tracks of different pairs is different. The identity of the control information reduces the effect of crosstalk on neighboring tracks.
摘要:
The device according to the invention is suitable for recording a rewritable information carrier such a CD-E covered by a phase-change recording layer. As is known, such an information carrier has a limited useful life because the recorded, optically readable patterns start deviating ever more from the desired form when recorded recurrently. The invention is also based on the recognition that this degradation is accelerated if a certain part of the track on the information carrier constantly accommnodates the same patterns, for example, if information blocks are recorded starting from fixed initial positions and the information is represented by the patterns in a specific manner. The device comprises means for shifting the initial position along the track over a distance randomly selected within predefined boundaries and/or for adapting the manner of representation. This causes constantly different patterns to be recorded, even if the same information is to be recorded in a specific part of the track. The information carrier described according to the invention has an additional margin between the information blocks to allow of the shifting of the initial position.
摘要:
A disc-shaped information carrier and a device for reading and/or writing information blocks in a track thereon which follows a helical or concentric path forming successive windings. For identifying each winding the information carrier also has a servo pattern thereon which includes position-information as well as synchronization elements. Such elements may be, for example, brief pulses in a continuous track wobble, and are distinguishable in adjacent windings based on a predetermined detectable parameter, such as alternating polarity or shifted relative phase positions. The device has a read/write head and a system control which during writing detects the synchronization elements and monitors whether a deviation has occurred signifying that the read/write head has wandered to an adjacent winding. In that event writing is interrupted. Thus, the least possible information in adjacent windings is overwritten in the case of disturbances resulting from shocks or defects of the information carrier. A read device is also described which interrupts reading if the winding identification provided by the synchronization elements signifies erroneous operation.