KR100198245B1 - Magneto-optical recording medium - Google Patents
Magneto-optical recording medium Download PDFInfo
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- KR100198245B1 KR100198245B1 KR1019910008938A KR910008938A KR100198245B1 KR 100198245 B1 KR100198245 B1 KR 100198245B1 KR 1019910008938 A KR1019910008938 A KR 1019910008938A KR 910008938 A KR910008938 A KR 910008938A KR 100198245 B1 KR100198245 B1 KR 100198245B1
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- 238000000034 method Methods 0.000 claims abstract description 16
- 229910000684 Cobalt-chrome Inorganic materials 0.000 claims abstract description 10
- 239000010952 cobalt-chrome Substances 0.000 claims abstract description 10
- 230000003287 optical effect Effects 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 5
- 230000005415 magnetization Effects 0.000 abstract description 14
- 229910052723 transition metal Inorganic materials 0.000 abstract description 5
- 229910045601 alloy Inorganic materials 0.000 abstract description 3
- 239000000956 alloy Substances 0.000 abstract description 3
- 230000008878 coupling Effects 0.000 abstract description 2
- 238000010168 coupling process Methods 0.000 abstract description 2
- 238000005859 coupling reaction Methods 0.000 abstract description 2
- 230000009467 reduction Effects 0.000 abstract description 2
- 230000008859 change Effects 0.000 description 6
- 238000004544 sputter deposition Methods 0.000 description 5
- 230000005389 magnetism Effects 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000005381 magnetic domain Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000003252 repetitive effect Effects 0.000 description 2
- 230000005374 Kerr effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
Abstract
본 발명은 희토-천이금속 합금막으로 된 광자기 기록매체에 관한 것으로, 좀 더 구체적으로는 인접해 있는 자기적 성질이 다른 2개의 자성층간의 교환결합(exchange coupling)에 의해 수직자화를 구성하는 것으로 이미 어떤 정보가 기록되어 있는 상태에서 일련의 소거과정이 필요없이 광변조 방식으로 직접 정보를 기록할 수 있는 희토-천이금속 합금막으로 된 광자기 기록매체에 관한 것이다.The present invention relates to a magneto-optical recording medium made of a rare earth-transition metal alloy film. More particularly, the present invention relates to a perpendicular magnetization by exchanging coupling between two magnetic layers having different magnetic properties. The present invention relates to a magneto-optical recording medium made of a rare earth-transition metal alloy film capable of directly recording information by a light modulation method without the need for a series of erasing steps in which information is already recorded.
즉, 두 개의 자성막 사이에 3∼9Å정도의 두께로 CoCr층을 제막함으로서 재기록시 잔류정보로 인한 CNR감소를 해결하였고 반복사용시의 에러율을 감소시켰으며 노이즈 레벨(noise level)의 증가를 방지하였다.In other words, by forming a CoCr layer with a thickness of about 3 ~ 9Å between two magnetic films, we solved the CNR reduction due to reoxygen residual information, reduced the error rate during repeated use, and prevented the increase of noise level. .
Description
제1도는 종래의 2층자성막을 갖는 광변조 직접 재기록(direct overwrite)용 디스크의 단면도이고,1 is a cross-sectional view of a conventional optical modulation direct overwrite disk having a two-layer magnetic film,
제2도는 본 발명의 3층자성막을 갖는 광변조 직접 재기록(direct overwrite)용 디스크의 단면도이며,2 is a cross-sectional view of a disk for optical modulation direct overwrite having a three-layer magnetic film of the present invention,
제3도는 광변조 방식에 이용되는 자성막의 이상적 온도의존도를 나타내는 그래프이고,3 is a graph showing the ideal temperature dependence of the magnetic film used in the light modulation method,
제4도는 바이어스 자장(bias field)에 따른 C/N(carrier-to-noise ratio)비의 변화를 나타내는 그래프이며,4 is a graph showing a change in carrier-to-noise ratio (C / N) ratio according to a bias field.
제5도는 기록진동수에 따른 C/N비의 변화를 나타내는 그래프이고,5 is a graph showing the change of the C / N ratio according to the recording frequency,
제6도는 반복기록회수에 따른 C/N비의 변화를 나타내는 그래프이고,6 is a graph showing the change of the C / N ratio according to the number of times of repeat recording
제7도는 광변조 직접 재기록 시스템의 기본개념도 및 기록과정을 나타내는 도면이다.7 is a diagram illustrating a basic conceptual diagram and a recording process of the optical modulation direct rewrite system.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
-○- : 종래의 직접 재기록(direct overwrite)에 대한 그래프-○-: Graph of conventional direct overwrite
-●- : 본 발명의 직접 재기록(direct overwrite)에 대한 그래프-●-: Graph of direct overwrite of the present invention
1 : 기판 2 : 보호막1: substrate 2: protective film
3 : 기억자성막 4 : 기준자성막3: memory magnetic film 4: reference magnetic film
5 : 상호확산방지막 6 : 레이저5: interdiffusion prevention film 6: laser
7 : 렌즈 8 : 기록막7: lens 8: recording film
9 : 바이어스 마그네트(Hb) 10 : 초기화 마그네트(Hini)9: Bias magnet (Hb) 10: Initialization magnet (Hini)
본 발명은 회토-천이금속 합금막으로 된 광자기 기록매체에 관한 것으로, 좀 더 구체적으로는 인접해 있는 자기적 성질이 다른 2개의 자성층간의 교환결합(exchange coupling)에 의해 수직자화를 구성하는 것으로 이미 어떤 정보가 기록되어 있는 상태에서 일련의 소거과정이 필요없이 광변조 방식으로 직접 정보를 기록할 수 있는 광자기 기록매체에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording medium made of a rare earth-transition metal alloy film. More particularly, the present invention relates to a perpendicular magnetization by exchanging coupling between two magnetic layers having different magnetic properties. The present invention relates to a magneto-optical recording medium capable of recording information directly in an optical modulation method without the need for a series of erasing steps in which information is already recorded.
광자기 기록매체는 기록막이 수직자화 기록막으로 되어 있고 정보의 1, 0을 자화의 방향으로 변화시켜 작은 자구(magnetic domain)을 형성시킴으로써 정보를 기록한다. 즉, 광자기 기록매체에 있어서 집적된(focusing) 레이저광을 기록막에 조사하면 기록매체의 일부의 온도가 국부적으로 큐리온도 이상으로 상승하여 해당부분이 자화를 잃게 됨으로서 반대편에 위치한 전자석(electro-magnetic coil)에 의해 외부자계가 인가되어 레이저가 조사된 부분만 바라는 방향으로 자화되어 반전자구를 형성함으로서 정보신호(signal)의 1비트(bit)에 해당하는 정보기록이 가능하게 된다. 또한, 기록된 정보는 기록매체에 직선편광(Linear polarized beam)을 반사시키고 그 직선 편광의 회전(Kerr effect)을 이용함으로서 정보를 재생시킬 수 있다.In the magneto-optical recording medium, the recording film is a vertical magnetization recording film, and information is recorded by changing one or zero of the information in the direction of magnetization to form a small magnetic domain. That is, when a laser beam focused on a magneto-optical recording medium is irradiated onto the recording film, the temperature of a portion of the recording medium rises locally above the Curie temperature, and the portion of the recording medium loses magnetization. An external magnetic field is applied by a magnetic coil to magnetize only the portion to which the laser is irradiated to form an inverted magnetic domain, thereby making it possible to record information corresponding to one bit of the information signal. The recorded information can also reproduce the information by reflecting a linear polarized beam on the recording medium and utilizing the Kerr effect of the linear polarized beam.
한편, 일본공개특허 소55-52535 및 소56-153546호는 정보의 소거와 재기록을 가능하게 하는 기록매체로서의 광자기 기록매체를 기재하고 있으나, 종래의 광자기 디스트 기술은 한 번 기록된 정보위에 다시 새로운 임의의 정보를 기록하려면 반드시 일련의 소거과정을 거친후에만 정보의 재기록이 가능해짐으로서 정보의 재기록 시간이 길어지는 단점이 있었다.On the other hand, Japanese Patent Laid-Open Nos. 55-52535 and 56-153546 disclose a magneto-optical recording medium as a recording medium that enables erasure and rewriting of information. In order to record new random information again, it is possible to rewrite the information only after a series of erasing processes, resulting in a long rewriting time of the information.
따라서, 소거과정이 필요없는 직접기록방법이 제안되고 있으며, 특히 광변조 방식에 의한 직접기록방법에 대한 연구가 활발히 진행되고 있다. 상기 광변조 방식의 경우, 자화의 방향을 반전시킬 때 고출력(High power)과 저출력(low power)의 변조로 1상태와 0상태를 기록하게 되는데 기존의 고출력으로 기록된 정보위에 저출력으로 자화반전을 시키면 고출력으로 기록시킨 자구의 크기(domain size)가 저출력으로 기록한 것보다 크기 때문에 잔류정보가 생겨 노이즈(Noise)의 원인이 될 뿐만 아니라 정보판독에 있어 에러(error)가 발생하게 된다.Therefore, a direct recording method that does not require an erase process has been proposed. In particular, research on a direct recording method using an optical modulation method has been actively conducted. In the optical modulation method, when the direction of magnetization is reversed, one state and zero state are recorded by modulation of high power and low power, and the magnetization reversal is performed at low power on the information recorded at the existing high power. In this case, since the domain size recorded at high output is larger than that recorded at low output, residual information is generated, which causes noise and errors in information reading.
또한, 2개의 희토-천이금속막이 인접해 있기 때문에 경계면에서 상호확산(interdiffusion)이 일어나 장시간 반복사용시 에러율(error rate)이 증가하게 되어 수명이 짧아지는 문제점이 있었다.In addition, since two rare earth-transition metal films are adjacent to each other, interdiffusion occurs at an interface, resulting in an increase in an error rate when prolonged repeated use, thereby shortening a lifespan.
따라서, 본 발명의 목적은 재기록시 잔류정보의 발생이 없으며 인접한 2개의 희토-천이금속막 사이의 상호확산이 일어나지 않는 직접 재기록이 가능한 광자기 기록매체를 제공하는데 있다.Accordingly, it is an object of the present invention to provide a magneto-optical recording medium capable of direct rewriting without generating reoxyoxy residual information and without interdiffusion between two adjacent rare earth-transition metal films.
상술한 목적 뿐만 아니라 용이하게 표출될 수 있는 다른목적들을 해결하기 위하여, 본 발명에서는 두 개의 자성막 사이에 3∼9Å정도의 두께로 CoCr층을 제막함으로써 재기록시 잔류정보로 인한 CNR감소를 해결하였고 반복사용시의 에러율을 감속시켰으며 노이즈 레벨(noise level)의 증가를 방지하였다.In order to solve not only the above-mentioned object but also other purposes that can be easily expressed, the present invention solves the CNR reduction due to the reoxyoxy residual information by forming a CoCr layer with a thickness of about 3 to 9 kV between two magnetic films. The error rate in repeated use was reduced and the increase of noise level was prevented.
본 발명을 좀 더 구체적으로 설명하면 다음과 같다.The present invention is described in more detail as follows.
광변조 방식을 이용한 직접 재기록용 광자기 기록매체의 자성층은 일반적으로 기준 자성막(Reference layer)과 기억자성막(Memory layer)의 2층막으로 되어 있으며, 각각의 자성막의 성질은 제3도에 도시된 바와 같이 온도에 따라 서로 다른 특성을 나타내는데 초기 상온에서는 기준자성막의 보자력이 기억자성막의 보자력보다 작아야 하고, 온도의 증가에 따라 두 개의 자성층은 자화를 잃기 시작하는데 기준 자성막의 큐리온도가 기억자성막의 큐리온도보다 높아야 한다. 즉, 상온에서 기억자성막의 보자력이 기준자성막의 보자력보다 작아야 하고, 가열시에는 기억자성막의 스위칭 자장(switching field)이 기준자성막보다 빠르게 감소하여야 한다.The magnetic layer of the magneto-optical recording medium for direct rewriting using the optical modulation method is generally composed of two layers of a reference magnetic layer and a memory layer. The characteristics of each magnetic layer are shown in FIG. As shown in the figure, it shows different characteristics according to temperature. At initial temperature, the coercive force of the reference magnetic film should be smaller than the coercive force of the memory magnetic film, and as the temperature increases, the two magnetic layers begin to lose magnetization. Should be higher than the Curie temperature of the magnetic film. That is, the coercive force of the memory magnetic film should be smaller than the coercive force of the reference magnetic film at room temperature, and during heating, the switching field of the memory magnetic film should decrease faster than the reference magnetic film.
또한, 광변조 방식에 의한 재기록을 위해서는 두 개의 기록용과 하나의 재생용 즉, 3개의 출력 레벨(level)을 갖는 레이저(pick up)가 있어야 하며, 기준자성막의 보자력보다 큰 자장을 낼수 있는 초기화 마그네트(initializing magnet)와 수백 Oe정도의 자장을 발생하는 정보기록용 바이어스 마그네트(bias magnet)가 필요하다.In addition, in order to rewrite by the optical modulation method, there must be two recording and one reproduction, that is, a laser having three output levels (pick up), and initialization capable of generating a magnetic field larger than the coercive force of the reference magnetic film. There is a need for an information recording bias magnet that generates a magnet (initializing magnet) and a magnetic field of several hundred Oe.
상기 조건을 만족하는 2층 자성막에 있어서, 제7도에 도시된 바와 같이 초기화 마그네트의 자화(Hini)의 방향이 아랫쪽(↓)이고, 바이어스 마그네트의 자화(Hb)의 방향이 윗쪽(↑)으로 향해 있다면, Hini에 의해 기준자성막의 자화방향이 아랫쪽(↓)으로 향하게 되고, 기억자성막은 보자력이 크기 때문에 상온에서는 영향을 받지 않는다. 이때 1과 0의 2진수 데이터에 상응하는 레이저를 고출력과 저출력으로 변조시키면 고출력의 경우에는 재질의 온도가 큐리온도까지 올라가게 되므로 기억자성막과 기준자성막 모두가 자성을 잃게 되고, 자성을 잃었던 재질은 냉각되면서 기준자성막의 방향이 바이어스 마그네트의 방향을 따르게 되고 기억자성막은 기준자성막의 자화방향에 따라 그대로 복사하게 된다. 또한, 저출력으로 가열하는 경우에는 기억자성막은 탈자되지만 기준자성막의 자화는 그대로 유지되며, 이때 자성을 잃었던 기억자성막은 기준자성막의 자화방향을 복사하게 된다. 즉, 고출력의 경우가 1상태라면 저출력의 경우 0상태로 기록할 수 있는 것이다.In the two-layer magnetic film that satisfies the above condition, as shown in FIG. 7, the direction of magnetization (Hini) of the initialization magnet is downward (↓), and the direction of magnetization (Hb) of the bias magnet is upward (↑). If the direction is in the direction of H, the magnetization direction of the reference magnetic film is directed downward (↓), and the memory magnetic film is not affected at room temperature because the coercive force is large. At this time, if the laser corresponding to binary data of 1 and 0 is modulated with high power and low power, the temperature of the material increases to Curie temperature in the case of high power, so that both the memory magnetic film and the reference magnetic film lose their magnetism and lose their magnetism. As the material cools, the direction of the reference magnetic film follows the direction of the bias magnet, and the memory magnetic film is radiated as it is according to the magnetization direction of the reference magnetic film. In the case of heating at a low output, the memory magnetic film demagnetizes, but the magnetization of the reference magnetic film remains unchanged. At this time, the memory magnetic film that lost its magnetism radiates the magnetization direction of the reference magnetic film. That is, if the high output is in the 1 state, the low output can be recorded in the 0 state.
따라서, 본 발명은 상기 메카니즘(mechanism)으로 정보를 직접 재기록할 수 있고, 종래 기술의 문제점을 해결하기 위하여 통상의 스퍼터링(sputtering)시스템을 사용하여 기억자성막과 기준자성막 사이에 CoCr층을 3∼9Å의 두께로 스퍼터링하여 기판/보호막/기억자성막/CoCr막/기준자성막/보호막의 구조를 갖는 광자기 기록매체를 제조하였다.Therefore, the present invention can directly rewrite information by the above mechanism, and in order to solve the problems of the prior art, a CoCr layer is formed between the memory magnetic layer and the reference magnetic layer by using a conventional sputtering system. Sputtering was performed to a thickness of ˜9 kHz to produce a magneto-optical recording medium having a structure of substrate / protective film / memory magnetic film / CoCr film / reference magnetic film / protective film.
다음의 실시예 및 비교예는 본 발명의 광자기 기록매체의 제조방법 및 이의 효과를 좀 더 구체적으로 설명하는 것이지만, 본 발명의 범주를 한정하는 것은 아니다.The following examples and comparative examples more specifically describe the manufacturing method and effects thereof of the magneto-optical recording medium of the present invention, but do not limit the scope of the present invention.
[실시예1]Example 1
4개의 챔버(chamber)로 구성된 스퍼터링 장치를 준비하고, 제1번 챔버의 타켓(Target)은 Si, 2번 타켓은 TbFe, 3번 타켓은 CoCr, 4번 타켓은 TbFeCo를 장착하고, Ar과 N2가스를 주입하여 통상의 방법으로 스퍼터링하여 Si3N4막, TbFe막, CoCr막, TbFeCo막, Si3N4막의 순서로 제막하였다. 각 층의 두께는 Si3N4막이 900Å, TbFe막이 500Å, CoCr막이8Å, TbFeCo막이 400Å이었다.A sputtering device consisting of four chambers is prepared, and the target of the first chamber is Si, the second target is TbFe, the third target is CoCr, the fourth target is TbFeCo, Ar and N injecting a second gas by sputtering in a conventional film-forming method was as Si 3 N 4 film, TbFe film, CoCr film, TbFeCo film, Si 3 N 4 layer sequence. The thickness of each layer was 900 Si of Si 3 N 4 film, 500 Å of TbFe film, 8 Å of CoCr film, and 400 Å of TbFeCo film.
제조된 시편의 보자력을 측정한 결과, 상온에서의 기억자성막(TbFe자성막)만의 보자력은 13KOe이었으며, 기준자성막(TbFeCo자성막)만의 보자력은 5KOe이었다.As a result of measuring the coercivity of the prepared specimens, the coercive force of only the memory magnetic film (TbFe magnetic film) at room temperature was 13 KOe, and the coercive force of only the reference magnetic film (TbFeCo magnetic film) was 5 KOe.
제조된 시편의 특성을 알아보기 위하여 다음과 같은 실험을 행하였다.In order to determine the characteristics of the prepared specimens, the following experiments were conducted.
광자기 디스크 드라이브 시스템을 이용하여 진동수 10MHz, 선속도 15m/s, 고출력(High Power: PH)은 16mW, 저출력(Low Power: PL)은 7mW로 바이어스 마그네트(Hb)를 변화시키면서 정보를 기록한 후 CNR을 측정하고, 그 결과를 제4도에 그래프로 도시하였으며, PH16mW, PL7mW, Hb 500 Oe, 진동수는 5MHz로 기록된 기존정보위에 소거과정없이 상기와 같은 파우어도 기록진동수를 변화시키면서 재기록한 후 CNR을 측정하고, 그 결과를 제5도에 그래프로 도시하였다. 또한 반복 기록시 노이즈 레벨(noise level)의 변화를 알아보기 위하여 PH는 16mW, PL은 6mW의 파우어, 진동수 2MHz로 반복재기록하면서 노이즈 레벨을 측정하고 그 결과를 제6도에 그래프로 도시하였다.Using a magneto-optical disk drive system, the frequency was recorded at 10 MHz, linear speed 15 m / s, high power (P H ) at 16 mW, and low power (P L ) at 7 mW, changing the bias magnet (Hb). After that, the CNR was measured and the results are shown graphically in FIG. 4, and P H 16mW, P L 7mW, Hb 500 Oe, and the frequency were recorded at 5 MHz without the erase process. After rewriting with change, the CNR was measured and the results are shown graphically in FIG. In addition, in order to examine the change of noise level during repeated recording, P H is 16mW, P L is 6mW, and the noise level is measured repeatedly with repetition of recording at 2MHz and the results are shown graphically in FIG. .
[비교예1]Comparative Example 1
3개의 챔버로 구성된 스퍼터링 장치를 사용하여 기판/Si3N4/TbFe막/TbFeCo막/ Si3N4의 구조를 갖는 종래의 광자기 기록매체를 실시예1과 동일한 방법으로 제조하고, 제조된 시편으로 실시예1과 동일한 실험을 행하여 그 결과를 제4, 5, 6도에 그래프로 도시하였다.A conventional magneto-optical recording medium having a structure of substrate / Si 3 N 4 / TbFe film / TbFeCo film / Si 3 N 4 was manufactured in the same manner as in Example 1 by using a sputtering apparatus composed of three chambers. Experiments were carried out in the same manner as in Example 1, and the results are shown graphically in FIGS. 4, 5, and 6 degrees.
제4도 및 제5도로부터 알 수 있는 바와 같이, 본 발명의 광자기 기록매체는 종래의 광자기 기록매체보다 전진동수 영역에서 CNR이 3∼5dB정도 향상되었음을 알 수 있으며, 본 발명의 광자기 기록매체에서는 재기록시 잔류정보가 거의 없음을 알 수 있었다.As can be seen from FIG. 4 and FIG. 5, the magneto-optical recording medium of the present invention can be seen that the CNR is improved by about 3 to 5 dB in the whole frequency region than the conventional magneto-optical recording medium. It was found that there is almost no regioxy residual information in the recording medium.
또한, 제6도로부터 종래의 광자기 기록매체에 반복재생시 104회 이상에서는 노이즈 레벨이 급격히 증가하는 반면, 본 발명의 광자기 기록매체에 반복재생시에는 106회 이상에서도 아무런 변화가 없어 기억자성막과 기준자성막 사이의 상호확산이 전혀 일어나지 않음을 알 수 있었다.In addition, in FIG. 6, the repetitive reproduction of the conventional magneto-optical recording medium rapidly increases the noise level at 10 4 times or more, while the repetitive reproduction of the magneto-optical recording medium of the present invention does not change any more than 10 6 times. The interdiffusion between the magnetic film and the reference magnetic film did not occur at all.
상술한 바와 같이, 본 발명에 따른 광자기 기록매체를 사용함으로써 임의의 정보를 기록한 후 새로운 정보를 기록할 때 기존정보의 소거과정에 소요되는 시간이 절약되므로 기록시간을 단축할 수 있었으며, 잔류정보가 거의 없게 되므로 CNR이 약 3∼5dB정도 향상되었고, CoCr층이 기준자성막과 기록자성막간의 상호확산을 방지하는 역할을 함으로써 장시간 반복사용후에도 노이즈 레벨이 전혀 증가하지 않았다.As described above, by using the magneto-optical recording medium according to the present invention, the recording time can be shortened because the time required for erasing the existing information is saved when recording new information after recording arbitrary information. Since the CNR improved by about 3 to 5 dB, the CoCr layer prevented the interdiffusion between the reference magnetic film and the recording magnetic film, so that the noise level did not increase at all even after repeated use for a long time.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019910008938A KR100198245B1 (en) | 1991-05-30 | 1991-05-30 | Magneto-optical recording medium |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019910008938A KR100198245B1 (en) | 1991-05-30 | 1991-05-30 | Magneto-optical recording medium |
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| Publication Number | Publication Date |
|---|---|
| KR920022242A KR920022242A (en) | 1992-12-19 |
| KR100198245B1 true KR100198245B1 (en) | 1999-06-15 |
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| KR1019910008938A KR100198245B1 (en) | 1991-05-30 | 1991-05-30 | Magneto-optical recording medium |
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| KR (1) | KR100198245B1 (en) |
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