Abstract: An apparatus for recording data having two transition states consisting of leading and trailing edges on the tracks of a disc rotating at a predetermined angular velocity via a head, includes a circuit for generating a plurality of modulated data whose leading edge transitions are synchronized with respect to a transitional state of the recording data and whose trailing edge transitions are delayed with respect the opposite transitional state of the recording data, according to the respective predetermined delay characteristics; a circuit for selecting one of the plurality of delayed data generated from the delayed data generating circuit according to the positions at which the data is to be recorded; and a circuit for modulating the data according to the delayed data selected by the selecting circuit and providing the modulated data to the head.

Abstract: A method and apparatus for reading data contained in blocks arranged in a number of tracks on a storage medium, wherein movement of the storage medium causes the tracks to deviate from a nominal path, are disclosed. In the method and apparatus, a set of multiple read elements is disposed relative to the storage medium so that each of the read elements covers at least a portion of the expected area in which a track to be read will be found, given movement of the storage medium. Each of the read elements has a read channel uniquely associated therewith, and all of the read elements are used simultaneously to read the data blocks. The read channels are monitored, and a first arriving, correctly read block is selected from among the channels, the selected block being the next block in a sequence, following a previously selected block. The data blocks are then stored at memory locations correlated to their position in the sequence on the storage medium.

Abstract: A method and apparatus for optical recording addresses a problem of edge shift which occurs during the recording. The apparatus includes a rotating mechanism for rotating an optical medium, and an optical head having a light source for recording information on the optical medium. A moving mechanism moves the optical head to a predetermined position on the optical medium, and a recording controlling device controls light source of the optical head in accordance with a recording pulse. The recording controlling device includes a pulse width measuring device for measuring the pulse width of a recording pulse, and fall controlling device effects a recording compensation by advancing a fall of the recording pulse with a lead, such that the lead increases with the measured pulse width.

Abstract: A hybrid digital/analog video recorder prevents both analog and digital copying. The recorder (including a digital tape deck) inputs and outputs both analog and digital video signals. At the analog input, a detector detects conventional copy protection in the analog input video, and in response disables recording thereof. At the digital input, a first detector detects anti-copy bits present in the input material and in response prevents recording. A second bit detector detects serial copy prevention scheme bits, and in response adds an anti-copy bit to the input digital stream, preventing later copying of such material. When another bit detector detects anti-copy bits present in the playback digital data stream prior to conversion to analog, an analog copy protection signal modifies the output analog signal, inhibiting copying of the output signal. In another version, a specially adapted video recorder or playback device copy protects video source material which for technical reasons is not copy protectable.