Abstract:
In an information recording/reproducing apparatus constructed of: a buffer for storing therein consecutive recording data in a unit of two dimensional conversion; a coding device for converting the consecutive recording data into a two-dimensional data arrangement arranged by "n" lines and "m" columns corresponding to said unit of data; a recording device for subdividing said two-dimensional data arrangement arranged by "n" lines and "m" columns so as to be read out, and for controlling "m" pieces of light sources in accordance with these data series; and an optical apparatus for converging luminous fluxes from said "m" pieces of light sources so as to form "m" pieces of spots on a disk plane, the recording data is recorded on the disk plane as an optically distringuishable pit group having two-dimensionally extended areas arranged by "n" lines and "m" columns. During a reproducing operation, the reflected light is detected by "m" pieces of detectors; "m" columns of one-dimensional data series are generated from the reflected light detected by these detectors in a generator; and also consecutive data is reproduced from the two dimensional data arranged by "n" lines and "m" columns in a decoder.
Abstract:
An optical method for recording, reproducing, and erasing a digital signal of a mark length recording system onto/from an optical recording medium such as an optical disc or the like eliminates a fluctuation of the edge position of the reproduction signal due to heat interference between pits, thereby reducing a fluctuation of the edge position due to a fluctuation of external environmental conditions. For this purpose, there are proposed the following methods: 1) the shape of the recording pulse waveform is controlled, 2) the density at which data is recorded to the disc is variably set in accordance with the disc position, 3) a test recording is executed prior to recording user data, and the like. With these methods, a superhigh density optical recording can be realized.
Abstract:
In a write control method on an optical recording, at least one shift amount selected from the defocus amount of a laser beam on a recording medium, the shift amount of a recording position on a recording track and the shift amount of laser power during recording is controlled such that the selected amount falls within a predetermined range. Subsequently, a trial signal is trially recorded at a plurality of trial zones on the recording medium by using a laser power value as a parameter. The recorded trial signal is read and a difference .DELTA.V between center levels of a highest density waveform and a lowest density waveform is detected. In connection with each trial zone, the laser power value when a reading trial signal which makes the difference .DELTA.V minimum is recorded is defined as an optimum recording power value. Regular data is recorded at a predetermined storage area on the recording medium by using an optimum laser power value determined in connection with a trial zone closest to the predetermined storage area.
Abstract:
A magneto-optical disk recording control method using the mark length recording method wherein the marks and gap regions between marks are recorded on the surface of the disk by maintaining a constant temperature distribution during the recording. The laser is driven to a non-recording level in gap regions between marks that exceed a base recording level used for reproduction of the marks. When a mark is recorded, the laser power is increased to a recording power level and after the mark has been recorded, the laser power level is reduced to the base power level, followed by being raised to the gap recording level. Control of the laser is performed by superposing a plurality of pulse trains that are synchronized with respect to a clock having a cycle T. The pulse trains are derived from the code train to be recorded and have pulses with a duration that is an integral multiple of (1/2)T. If the pulse width of the recording code train exceeds 2T, then the laser is controlled to reach a first power level in accordance with pulses of a first pulse train, be reduced to the gap recording level and then raised to a second power level in accordance with a second recording pulse train to maintain the temperature distribution constant during the recording of the mark. For the recording of longer marks, the laser is controlled to vary between the second power level and the gap recording level.
Abstract:
A developer composition for a lithographic printing plate provided with a coated layer composed of a photosensitive polymer having in the main chain thereof groups of formula (I) ##STR1## wherein X and Y independently represent hydrogen, halogen, cyano or nitro, and n is an integer of 1 or 2, comprising ethylene glycol monophenyl ether and at least one acid selected from the group consisting of a mineral acid, an organic carboxylic acid and an organic sulfonic acid.