摘要:
An optical disk comprising a substrate 4, and a plurality of tracks 269 to 273 formed on the substrate 4, wherein the plurality of tracks 269 to 273 include groove tracks 270, 272 consisting of a plurality of grooves mutually space apart by a fixed space, and land tracks 269, 271, 273 consisting of areas between the groove tracks, wherein the borders 14, 15 between the groove tracks and the land tracks represent information using the waveforms from their wobbling patterns, wherein the period of the wobbling waveforms of the borders 14, 15 are constant on each border, but the wobbling waveforms of the opposite portions of the borders across the track are shifted in phase by a predetermined phase difference.
摘要:
A liquid crystal display system is provided with a driving circuit which corrects the display position in a vertical direction to obtain an excellent display area even when the total vertical line number is short. According to the driving circuit, by switching the output alternating signal GM input to a scan driver 701-1 in a scan driving circuit 104, a selection voltage Vgon is reflected to all the output terminals of the scan driver 701-1 to switch plural lines at the same time and perform a write-in operation. In a scan driver 701-2 and subsequent scan drivers in the scan driving circuit 104, an FLM signal is input to successively reflect the selection voltage Vgon to the output terminals thereof and successively select the line, thereby performing a write-in operation.
摘要:
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.
摘要:
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.
摘要:
A recording mark having width (disk radius direction) larger than length (disk rotation direction) is formed by using the light intensity modulation method. The recording mark is ring-shaped. The ring part differs in optical characteristic from a part surrounded by the ring part. In order to form a ring-shaped mark, laser light having predetermined intensity is continuously radiated onto the recording medium. By modulating the intensity of the laser light, information is overwritten. The ring-shaped mark is set to have a width based upon the intensity of radiated laser light and the characteristic of the recording film.
摘要:
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.
摘要:
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.
摘要:
An optical disc for a sample servo type optical disc system. Servo areas disposed periodically on each of tracks of the optical disc are sequentially offset relative to those on the adjacent tracks as viewed in the radial direction by a predetermined distance. An apparatus used for signal read-out from the optical disc comprises a circuit for detecting a servo signal originating in servo pits from a detection signal output from a photodetector, a circuit for generating a clock signal synchronized with the servo signal, a counter for outputting a count value representative of the counted clocks at the timing of the servo signal, and a circuit for generating a light spot velocity signal from the count value.
摘要:
An optical memory device includes a cylindrically-shaped optical information recording medium and at least one optical head disposed around the information recording medium for irradiating the information recording medium with a light spot for recording or reproduction of information. The optical head has light spot moving means incorporated therein for the irradiation position of the light spot. The recording or reproduction of information is achieved by causing the light spot moving means to perform tracking control so that the light spot follows a desired track in an area within a range of movement of the light spot by the light spot moving means (or an infromation recording zone) in a state in which the relative positional relationship between the optical head and the cylindrically-shaped information recording medium in the direction parallel to the direction of the rotation axis of the information recording medium is fixed, with the optical head being not moved. The device can be constructed so that the position of either the optical head or the cylindrically-shaped information recording medium relative to the other in the direction parallel to the direction of the rotation axis of the information recording medium is mechanically moved, thereby making it possible to cahnge the information recording zone in the range of movement of the light spot by the light spot moving means to another information recording zone.
摘要:
A record carrier having a disc-shaped substrate and a recording layer for optically writing information therein is disclosed which includes a guide groove extended in the rotational direction of the record carrier so that a plurality of revolutions of the guide groove are spaced apart from each other in radial directions of the record carrier, and a pit pattern provided between adjacent guide grooves, at positions arranged at intervals in the above rotational direction, for detecting the deviation of a light spot from the center line between adjacent guide grooves. The recording/reproducing operation for this record carrier is performed in such a manner that the first tracking error signal is detected from diffracted light from the guide groove, the second tracking error signal is detected from the pit pattern, and information is recorded in and reproduced from a land formed between adjacent guide grooves in a state that a tracking operation is performed using the first and second tracking error signals. The second tracking error signal detected from the pit pattern is not affected by the tilting of the record carrier and the movement of the light spot. When a tracking signal obtained by adding the first and second tracking error signals to each other, is used in a closed-loop tracking system, a stable tracking operation can be performed. The polarity of the pit pattern is reversed on every track, and hence a polarity pit having a depth of .lambda./4 (where .lambda. indicates the wavelength of a reproducing light beam) is provided in the record carrier, to reverse the polarity of the second tracking signal on every track on the basis of a signal from the polarity pit.