摘要:
A super high density optical disk apparatus is obtained by using an exchangeable recording medium having a recording capacity of at least 1.5 Gb/in.sup.2 in an optical recording and reading apparatus for recording or reading at least using a laser beam or by using one of means which can record on a recording medium only once and means which can record at least two times repeatedly as recording means to be used.
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:
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:
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 super high density optical disk apparatus is obtained by using an exchangeable recording medium having a recording capacity of at least 1.5 Gb/in.sup.2 in an optical recording and reading apparatus for recording or reading at least using a laser beam or by using one of an element which can record on a recording medium only once and another element which can record at least two times repeatedly as recording elements to be used.
摘要:
An optical recording control method determines an optimum recording laser power by effecting a test recording before information to be recorded is recorded on a disk. The recording laser power is formed of a plurality of powers. A relationship among the plurality of laser powers is regulated by power level ratios between respective powers, whereby a power used when a laser light is radiated on the disk can be controlled to be constant independent of an ambient temperature and a structure of a disk. Therefore, accurate recording marks can be formed on the disk.
摘要:
A method of recording data into a recording medium by forming a recording region which is physically different from the nonrecorded portions is disclosed. The optical data recording/reproducing method includes a first trial writing operation in which trial writing data are recorded into the recording medium while changing the recording power conditions, the recorded trial writing data are reproduced, and the reproduced trial writing data are evaluated to set an optimum recording power. The method also includes a second trial writing operation in which trial writing data are recorded into the recording medium while changing the servo conditions, the recorded trial writing data are reproduced, and the reproduced trial writing data are evaluated to set optimum servo conditions.
摘要:
A magneto-optical disk system includes a magneto-optical disk and a disk drive. The magneto-optical disk drives provides a function of controlling the shape of a recorded domain by using a short wavelength laser beam and a test recording and a function of recording a using a pulse train. The magneto-optical disk has a laminated layer structure capable of obtaining a high S/N ratio and stabilizing a heat conduction. The magneto-optical disk drive with the recorded domain shape control function using a short wavelength laser beam and a test recording and with the pulse train recording record function is organically coupled with the magneto-optical disk having the laminated layer structure with a stabilized heat conduction to make the disk and the disk drive have an integrity therebetween, providing a magneto-optical disk having a recording capacity four times as large as the first generation magneto-optical disk system.
摘要:
When record marks are recorded on a recording medium while making a code symbol "1" of data by obtained coding write information according to a coding system having no DC free property correspond to every edge of the record marks, the recording is effected while inserting resynchronizing signals into the write information with a constant interval. For the resynchronizing signal either one selected between a first resynchronizing code pattern, in which the number of symbols "1" contained therein is even, and a second resynchronizing code pattern, in which the number of symbols "1" is odd, so that an accumulated charge obtained from the run length of the coded data approaches zero is used. Each of the first and the second resynchronizing code pattern contains at least a specified pattern, which doesn't meet the coding rule. The selection is effected by adding a run length switching code to the resynchronizing signal and by switching it to "0" or "1" depending on an output of a run length measuring circuit and a run length judging circuit. In this way it is possible to suppress fluctuations in the level of a reproduced signal obtained from the record marks recorded on the recording medium and to realize a stable data detection by using the original waveform detection method, by which the reproduced signal is converted into a binary signal by using a suitable slice level.