摘要:
A multi-stack optical data storage medium (20) for rewritable recording using a focused radiation beam (30), entering through an entrance face (25) is described. The medium (20) has a substrate (1a, 1b) and an L0 recording stack (2) and an L1 recording stack(3) both comprising a phase-change type L0 and L1 recording layer and the recording stacks are separated by a transparent spacer layer (4). The L0 recording stack (2) is present at a position closest to the entrance face (25) and has an optical transmission of TL0a and TL0c when the phase-change layer respectively is in the amorphous phase and in the crystalline phase. The medium (20) contains pre-recorded information modulated in at least one of: an embossed pregroove (21) in the substrate (1a, 1b), embossed pits in the substrate and recorded phase-change marks in at least one of the recording layers L0 and L1 (6, 11). The pre-recorded information contains a flag whether formatting of the L0 recording layer of the L0 recording stack (2) is needed depending on the transmission values TL0a and TL0c of the L0 recording stack (2). In this way it is achieved that the medium (20) has a good playability, recordability and random access behavior even when the L0 recording layer (2) has been partially recorded with information.
摘要:
A radiation detector array for radial tracking error detection for a dual-wavelength optical scanning device. Three spot detectors (100, 102, 104) for conducting three spot radial tracking error detection at each of the two different wavelengths. Satellite spot detectors (102, 104) are divided into three detector elements and one switched depending on the wavelength currently being used for scanning.
摘要:
The invention relates to a lighting device for generating output illumination having at least one directional characteristic. The lighting device includes at least one light-emitting device and at least one optical element disposed in an optical path of the light-emitting device. The lighting device also includes a screen-like member for changing at least one physical property of light passing therethrough and an optical device for generating an intermediate image on the screen-like member. The screen-like member and the optical device are located in the optical path between the light-emitting device and the optical element projecting the intermediate image.
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 neighbouring tracks. The control information in both tracks of a pair is identical and the control information on tracks of different pairs is different. The identity of the control information reduces the effect of crosstalk on neighbouring tracks.
摘要:
An optical device for scanning an optical record carrier (20) has a radiation source (25) that can emit two radiation beams of different wavelength along different optical paths (28, 29). The emitted radiation is focused on the record carrier and reflected back to a detection system (40). A beam combiner 43 is arranged in the optical path between the radiation source and the detection system for combining the two radiation beams on one optical path, thereby allowing the use of a single detection system for both radiation beams. The beam combiner includes a grating that passes one of the beams undiffracted and diffracts the other beam mainly in the first order. The profile of the grating lines show alternating slanting grooves and slanting lands.
摘要:
A record carrier (1) is described comprising a servo track (4) indicating an information track (9) intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track (4) 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:
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 with comprises 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 said 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:
A record carrier (1) is described comprising a servo track (4) indicating an information track (9) intended for recording information blocks represented by marks having lengths expressed in channel bits, which servo track (4) 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:
The rewritable data storage medium (1) has a rewritable recording layer (9) provided with a tracking structure (8). Said layer (9) has a data recording area (5). An erasable identification mark is present in an identification mark area (4, 4') other than the data recording area (5). The data recording area (5) has a first tracking structure (8'), whereas the identification mark area (4, 4') is substantially free from a tracking structure or has a second tracking structure (8') substantially different from the first tracking structure (8'). Thus erasure of the identification mark is practically impossible, because the location of the erasing spot of a recorder cannot be controlled precisely in radial direction.