摘要:
In a magneto-optical disk for recording, reproduction or erasing with a laser beam, which comprises a film of four-layer structure consisting of a first dielectric layer (2), a magneto-optical recording layer (3), a second dielectric layer (4) and a metallic layer (5), laid on a disk substrate (1) provided with guide tracks, temperature distribution of the magneto-optical recording layer (3) is controlled by controlling the thermal diffusivity of the metallic layer (5), and recording/reproduction/erasing repetition characteristics are improved thereby. In the disk of the present structure, the temperature is elevated in a broader area from the center of laser beam, and thus a thoroughly broad erasing domain width taking a track offset into account can be obtained and not recording domains remain after the erasing. The reproduced signal output is increased by 4 dB, as compared with that obtained by a disk of three-layer structure without any metallic layer, because the beam utilization efficiency is increased owing to both Kerr effect and Faraday effect. When the disk of the present structure is subjected to field modulation recording, tails of arrow-feather-shaped recording domains peculiar to the field modulation recording can be shortened and interbit interferences can be overcome, resulting in an increase in C/N (S/N) ratio and the high density recording can be made. By endowing a Kerr enhancement action to the second dielectric layer (4) and a protective action on the magneto-optical layer (3) to the first dielectric layer (2), only the reliability can be improved without lowering the C/N ratio. By improving the corrosion resistance of the magneto-optical recording layer, the first dielectric layer (2) can be omitted to the contrary, and a magneto-optical disk of simple structure can be obtained and used as memory for domestic applications or communication fields.
摘要:
A magneto-optical recording medium having a substrate (1) and a magnetic layer composed of at least a recording layer (3) and a supporting layer (4) and being capable of retrieving information by utilizing the fact that when it is irradiated with a laser beam it produces the magneto-optical effect which affects its reflected light, characterized in that the recording layer (3) has a lower Curie temperature than has the supporting layer (4) and the recording layer (3) is thin enough for the laser beam to pass through. A magneto-optical recording medium as defined above, wherein the supporting layer (4) is composed of a first supporting layer and a second supporting layer, and the recording layer (3), the first supporting layer, and the second supporting layer have Curie temperatures of T₁, T₂, and T₃, respectively, which satisfy the following relationship. T₁ A magneto-optical recording medium defined as above, wherein the recording layer (3) has a higher Curie temperature than has the supporting layer (4). Owing to the above-mentioned features, the magneto-optical recording media of the present invention are capable of overwriting and have improved recording sensitivity.
摘要翻译:一种磁光记录媒体,它具有基片(1)和至少由记录层(3)和支持层(4)构成的磁性层,并且能够利用这样的事实来检索信息,即当它被照射 激光束产生影响其反射光的磁光效应,其特征在于记录层(3)具有比支撑层(4)低的居里温度,并且记录层(3)对于激光来说足够薄 光束通过。 一种如上定义的磁光记录介质,其中支撑层(4)由第一支撑层和第二支撑层组成,并且记录层(3),第一支撑层和第二支撑层具有居里 温度T 1,T 2和T 3分别满足以下关系。 T 1
摘要:
A magneto-optical recording medium having a substrate (1) and a magnetic layer composed of at least a recording layer (3) and a supporting layer (4) and being capable of retrieving information by utilizing the fact that when it is irradiated with a laser beam it produces the magneto-optical effect which affects its reflected light, characterized in that the recording layer (3) has a lower Curie temperature than has the supporting layer (4) and the recording layer (3) is thin enough for the laser beam to pass through. A magneto-optical recording medium as defined above, wherein the supporting layer (4) is composed of a first supporting layer and a second supporting layer, and the recording layer (3), the first supporting layer, and the second supporting layer have Curie temperatures of T₁, T₂, and T₃, respectively, which satisfy the following relationship. T₁ A magneto-optical recording medium defined as above, wherein the recording layer (3) has a higher Curie temperature than has the supporting layer (4). Owing to the above-mentioned features, the magneto-optical recording media of the present invention are capable of overwriting and have improved recording sensitivity.
摘要:
In a magneto-optical disk for recording, reproduction or erasing with a laser beam, which comprises a film of four-layer structure consisting of a first dielectric layer (2), a magneto-optical recording layer (3), a second dielectric layer (4) and a metallic layer (5), laid on a disk substrate (1) provided with guide tracks, temperature distribution of the magneto-optical recording layer (3) is controlled by controlling the thermal diffusivity of the metallic layer (5), and recording/reproduction/erasing repetition characteristics are improved thereby. In the disk of the present structure, the temperature is elevated in a broader area from the center of laser beam, and thus a thoroughly broad erasing domain width taking a track offset into account can be obtained and not recording domains remain after the erasing. The reproduced signal output is increased by 4 dB, as compared with that obtained by a disk of three-layer structure without any metallic layer, because the beam utilization efficiency is increased owing to both Kerr effect and Faraday effect. When the disk of the present structure is subjected to field modulation recording, tails of arrow-feather-shaped recording domains peculiar to the field modulation recording can be shortened and interbit interferences can be overcome, resulting in an increase in C/N (S/N) ratio and the high density recording can be made. By endowing a Kerr enhancement action to the second dielectric layer (4) and a protective action on the magneto-optical layer (3) to the first dielectric layer (2), only the reliability can be improved without lowering the C/N ratio. By improving the corrosion resistance of the magneto-optical recording layer, the first dielectric layer (2) can be omitted to the contrary, and a magneto-optical disk of simple structure can be obtained and used as memory for domestic applications or communication fields.
摘要:
An information recording medium (4) having land sections (271) and groove sections (272) which have borders that comprise: a pair of wobbles (14,15) having wobbling waveforms 180° out of phase, wherein position control information is indicated by the wobbling waveforms 180° out of phase; and wobbles having a predetermined phase inserted at fixed intervals; a recording method for an information recording medium (4) having land sections (271) and groove sections (272) which have borders comprising a pair of wobbles (14,15) having wobbling waveforms 180° out of phase, wherein position control information is indicated by the wobbling waveforms 180° out of phase, and wobbles having a predetermined phase inserted at fixed intervals; the method comprising: obtaining the wobbling waveforms, and recording information based on the position control information; a reproducing method for an information recording medium (4) having land sections (271) and groove sections (272), which have borders comprising: a pair of wobbles (14,15) having wobbling waveforms 180° out of phase, wherein position control information is indicated by the wobbling waveforms 180° out of phase, and wobbles having a predetermined phase inserted at fixed intervals; the method comprising: reproducing information based on the position control information, obtained from the wobbling waveforms.
摘要:
An optical recording medium is disclosed in which the tracks include groove portions and land portions alternately arranged in the radial direction, wherein a plurality of prepits including the address information prepits of first and second prepits portions are meanderingly arranged with respect to center lines of the groove and land portions; and wherein prepits among the plurality of prepits are arranged at a predetermined interval such that specific prepits present in the meanderingly arranged prepits are always reproduced when an optical spot having a predetermined spot diameter irradiated on the optical recording medium scans the information recording area in the circumferential direction. An optical information processing apparatus for such a medium is also disclosed. The apparatus has means to irradiate a light spot having a predetermined spot diameter such that one specific prepit among the prepits is always reproduced.
摘要:
An information recording method for recording information by forming record marks (6) in a data region of a recording medium (8) such that the information corresponds to both ends of each of the record marks. First and second adjustment or guard regions (22, 25) are provided before and after the data region (23). The lengths of the first and second adjustment regions are changed with the start position of the first adjustment region being changed such that the position of the data region is shifted. In addition, when the same information is recorded a plurality of times, an array of record marks (6) recorded on the recording medium (8) in association with the information includes an array in which the record marks (6) and the spaces (7) between the marks are reversed each other in their positions.