Abstract: A record carrier on which information is recorded in the form of first variations caused by the presence or absence of information marks along a recording track, such variations representing an information signal. The record carrier also exhibits second variations in the form of changes in the position of the information marks in a direction transversed to the track direction. The second variations having a frequency spectrum substantially entirely outside the frequency spectrum of the first variations. The second variations are detectable by the same playback transducer which detects the first variations, and the presence of the second variations may be necessary to enable the transducer to detect the first variations.

Abstract: Playback apparatus for a record carrier on which information is recorded in the form of variations of a first physical parameter. The playback apparatus scans the record carrier by means of a transducer which is responsive to the variations of the first physical parameter. An information recovery circuit recovers the information from a detection signal produced by the transducer. The record carrier also exhibits a variation of a second physical parameter, which differs from the first physical parameter but is of a type which is detectable by the same transducer. A detection circuit detects the presence of the second variation on the basis of a further detection signal produced by the transducer. A circuit controlled by the detection circuit enables the information recovery circuit in the event that the presence of the second variations is detected.

Abstract: Record carrier on which a main data file and a control file have been recorded, method of and device for recording the main data file and the control file, and device for reading the record carrier. A record carrier (184) is described on which main data files (TV/4, TV, . . . , 256 TV) and a control file (BB; IIDB) have been recorded, the control data in the control file being intended for controlling the reproduction of representations of the main data in the main data file during or after read-out of the main data file. The main data file and the control file are derived from a main data signal and a control data signal respectively in accordance with the same formatting and coding rules. The control data signal comprises packets (151) of n identical control data bit groups (150), n being an integer greater than or equal to 2.

Abstract: An information system including a record carrier and a playback apparatus. Information has been recorded on the record carrier in the form of variations of a first physical parameter. The playback apparatus scans the record carrier by means of a transducer which is responsive to the variations of the first physical parameter. An information recovering circuit recovers the information from a detection signal received from the transducer. The record carrier exhibits second variations of a second physical parameter, which differs from the first physical parameter but which second variations are of a type that are detectable by the transducer. A detection circuit detects the presence of the second variations on the basis of a detection signal received from the transducer. A circuit responsive to the detection circuit enables the information recovering circuit when the presence of the second variations is detected causing it to recover the information.

Abstract: A picture retrieval system is which comprises a record carrier (184) and a read device (11). A coded picture (8 TV, 16 TV, 64 TV, 256 TV) composed of consecutive coded picture lines is recorded in a continuous track (20) of the record carrier (184). The read device scans the track to read coded picture lines recorded in the track and moves the read head (280) to a track portion having a selected address with a certain search accuracy. Together with the coded picture lines (APDB) a line number (LN) and a line synchronization are recorded in the track (20). The line number specifies the sequence number of the relevant picture line in the coded picture. The line synchronization specifies the beginning of the relevant picture line. Moreover, addresses (ADLN#1, . . . , ADLN#1009) for a number of coded picture lines of the coded picture are recorded in a portion (IIDB) of the track, to specify the positions where the relevant picture lines have been recorded in the track (20).

Abstract: An information system including a record carrier and a playback apparatus. Information has been recorded on the record carrier in the form of variations of a first physical parameter. The playback apparatus scans the record carrier by means of a transducer which is responsive to the variations of the first physical parameter. An information recovering circuit recovers the information from a detection signal received from the transducer. The record carrier also exhibits second variations of a second physical parameter, which differs from the first physical parameter, but which second variations are of a type that are detectable by the transducer. A detection circuit detects the presence of the second variations or a predetermined property thereof (e.g., that they exhibit a predetermined variation pattern) on the basis of the detection signal received from the transducer.

Abstract: A record carrier, a playback apparatus and a system including the record carrier and the playback apparatus. Information has been recorded on the record carrier in the form of variations of a first physical parameter. The playback apparatus scans the record carrier by means of a transducer which is responsive to the variations of the first physical parameter. An information recovering circuit recovers the information from a detection signal received from the transducer. The record carrier exhibits second variations of a second physical parameter, which differs from the first physical parameter, but which second variations are of a type that are detectable by the transducer. A detection circuit detects the presence of a predetermined property of the second variations (e.g., that the second variations exhibit a modulation pattern representing a code) on the basis of a detection signal received from the transducer.

Abstract: A read device (320) for reading a record carrier (184) on which coded pictures (4TV, TV, TV/4) have been recorded. The recorded coded pictures represent pictures made up of a matrix of P rows of Q pixels (p). The dimension of the pixels in a horizontal direction is substantially equal to the dimension of the pixels in a vertical direction. A read unit (6) reads the recorded coded pictures (4TV, TV, TV/4) from the record carrier (184). The device comprises a picture converter, which preferably comprises a sample rate converter (290), for converting the read-out coded pictures into an adapted coded picture comprising P'.times.Q' coded pixels. The sample rate converter is arranged in a data path between the read unit (6) and a picture memory unit (321). The picture memory unit (321) supplies a coded picture representing a picture made up of pixels (p') whose ratio between the dimension in the horizontal direction and the dimension in the vertical direction is substantially equal to Q/P, P and Q being integers.

Abstract: An apparatus for reading picture data stored on a record carrier for first and second pictures, and providing an output video signal which changes smoothly from the first to the second picture. The apparatus has a single picture memory having storage locations for values representing individual pixels, and a converter for converting signal values fetched from the memory into a video signal. Data for a new picture are read into the memory without such adaptation as filtering or correcting color resolution. During intervals when the memory is not otherwise being accessed, newly recorded data are adapted and the adapted data are then stored. Priority are given to fetching data for the video generator, and loading data read from the record carrier.

Abstract: A reproducing apparatus has means for reproducing for a user images and audio items stored on a record carrier (compact disc). The apparatus is controlled by a simple microcontroller running a predetermined program. To enable items to be presented to the user in a reproduction sequence with user-selected branching, the desired reproduction sequence is broken into selection points and linear reproduction sequences. A selection item is stored on the disc for each selection point, while a sequence item is stored for each linear reproduction sequence, these sequence and selection items containing further item references to link them into the described composite reproduction sequence. The logic and storage requirements imposed on the microcontroller are minimal.