JP3165270B2 - Optical magnetic information recording / reading method and optical magnetic recording medium - Google Patents
Optical magnetic information recording / reading method and optical magnetic recording mediumInfo
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- JP3165270B2 JP3165270B2 JP00033593A JP33593A JP3165270B2 JP 3165270 B2 JP3165270 B2 JP 3165270B2 JP 00033593 A JP00033593 A JP 00033593A JP 33593 A JP33593 A JP 33593A JP 3165270 B2 JP3165270 B2 JP 3165270B2
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- information
- optical
- recording medium
- diffraction grating
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、光学的磁気的情報記録
読み取り方法及びそのための光学的磁気的記録媒体に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording and reading optical magnetic information and an optical magnetic recording medium therefor.
【０００２】[0002]
【従来の技術】従来、コバルト等の強磁性体をフィルム
基材に斜め方向から蒸着することによりその方向に結晶
を成長させ、その蒸着の入射面に平行でフィルム基材に
沿う方向の磁気異方性を高めて磁気ヒステリシス特性の
保磁力、角形比を向上させ、磁気特性を向上させること
が知られている。2. Description of the Related Art Conventionally, a ferromagnetic material such as cobalt is vapor-deposited on a film substrate in an oblique direction to grow crystals in that direction, and a magnetic field parallel to the plane of incidence of the vapor deposition and along the film substrate. It is known that the anisotropy is enhanced to improve the coercive force and the squareness ratio of the magnetic hysteresis characteristics, thereby improving the magnetic characteristics.
【０００３】一方、コード情報等を回折格子の向きに対
応させて光学的に記録し、これを例えばバーコードの代
わりに用いることも提案されている。On the other hand, it has been proposed to optically record code information or the like in accordance with the direction of a diffraction grating and use the optical information instead of a bar code, for example.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、従来の
強磁性体の斜方蒸着の場合、磁気記録媒体の磁気特性
は、蒸着入射角の選択によってしか制御できなかった。
したがって、例えば１つの磁気記録媒体上の異なる位置
で異なる磁気特性を得ることはできなかった。また、従
来の斜方蒸着による場合は、磁気特性すなわち磁気異方
性を高めようとすると、蒸着入射角を大きくする必要が
あり、その結果、蒸着効率が低下するという欠点を有し
ていた。However, in the case of conventional oblique deposition of a ferromagnetic material, the magnetic characteristics of the magnetic recording medium can be controlled only by selecting the deposition incident angle.
Therefore, for example, different magnetic characteristics could not be obtained at different positions on one magnetic recording medium. Further, in the case of conventional oblique deposition, in order to increase the magnetic properties, that is, the magnetic anisotropy, it is necessary to increase the deposition incident angle, and as a result, there is a disadvantage that the deposition efficiency is reduced.
【０００５】しかも、従来の磁気記録媒体においては、
記録情報の改竄が容易であり、磁気記録媒体をセキュリ
ティ用に用いるには危険が伴っていた。[0005] Moreover, in the conventional magnetic recording medium,
It is easy to falsify recorded information, and there is a danger in using a magnetic recording medium for security.
【０００６】本発明はこのような状況に鑑みてなされた
ものであり、その目的は、強磁性体の斜方蒸着とレリー
フ回折格子パターンとを組み合わせて、光学的にも磁気
的にも読み取りが可能な光学的磁気的情報記録読み取り
方法及びそのための光学的磁気的記録媒体を提供するこ
とである。The present invention has been made in view of such a situation, and an object of the present invention is to combine optical oblique deposition of a ferromagnetic material and a relief diffraction grating pattern to read optically and magnetically. It is an object of the present invention to provide a possible optical / magnetic information recording / reading method and an optical / magnetic recording medium therefor.
【０００７】[0007]
【課題を解決するための手段】上記目的を達成する本発
明の光学的磁気的情報記録読み取り方法は、基板として
その表面に格子の向きに分布を有するレリーフ回折格子
パターンを形成したものを用い、そのレリーフ面に強磁
性体である金属及びその化合物を斜方蒸着して形成した
記録媒体に磁気記録をし、その磁気記録を読み取ると共
に、レリーフ回折格子パターンを光学的に読み取ること
を特徴とする方法である。According to the present invention, there is provided an optical / magnetic information recording / reading method using a substrate having a relief diffraction grating pattern having a distribution in the direction of a grating formed on a surface of the substrate. Magnetic recording is performed on a recording medium formed by obliquely vapor-depositing a ferromagnetic metal and its compound on the relief surface, and the magnetic recording is read and the relief diffraction grating pattern is optically read. Is the way.
【０００８】この場合、読み取られた磁気情報と光学情
報に基づいて記録情報の真実性を判定することができ
る。In this case, the authenticity of the recorded information can be determined based on the read magnetic information and optical information.
【０００９】また、本発明の光学的磁気的記録媒体は、
格子の向きに分布を有するレリーフ回折格子パターンを
表面に有する基板のレリーフ面に強磁性体である金属及
びその化合物を斜方蒸着して形成したものである。Further, the optical magnetic recording medium of the present invention comprises:
The ferromagnetic metal and its compound are formed by oblique deposition on the relief surface of a substrate having a relief diffraction grating pattern having a distribution in the direction of the grating on the surface.
【００１０】[0010]
【作用】本発明においては、格子の向きに分布を有する
レリーフ回折格子パターンを表面に有する基板のレリー
フ面に強磁性体である金属及びその化合物を斜方蒸着し
て形成した記録媒体に磁気記録をし、その磁気記録を読
み取ると共に、レリーフ回折格子パターンを光学的に読
み取るので、光学的情報と一対一対応の磁気的情報を同
時に記録読み出しができ、記録媒体のセキュリティ性、
認証性をさらに向上させることができる。また、何れか
の情報を改竄しようとしても、他方の情報が破壊されて
しまい、偽造が困難となる。In the present invention, magnetic recording is performed on a recording medium formed by obliquely depositing a ferromagnetic metal and a compound thereof on a relief surface of a substrate having a relief diffraction grating pattern having a distribution in the direction of the grating. Since the magnetic recording is read and the relief diffraction grating pattern is optically read, the optical information and the magnetic information in a one-to-one correspondence can be simultaneously recorded and read, and the security of the recording medium,
Authentication can be further improved. Further, even if any information is attempted to be falsified, the other information is destroyed, making it difficult to forge.
【００１１】[0011]
【実施例】以下、本発明の光学的磁気的情報記録読み取
り方法及び光学的磁気的記録媒体の実施例と原理につい
て説明する。本発明の原理を説明する前に、本発明の基
本となる磁気記録媒体の磁気特性制御方法について説明
する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and principles of an optical / magnetic information recording / reading method and an optical / magnetic recording medium according to the present invention will be described below. Before describing the principle of the present invention, a method for controlling the magnetic characteristics of a magnetic recording medium, which is the basis of the present invention, will be described.
【００１２】まず、一つの例として、強磁性体であるコ
バルトを斜方蒸着した。斜方蒸着は、図１に示すよう
に、蒸着源１としてコバルトを用い、基板２表面に入射
角θ＝７０°で行った。入射角θは、基板２面の法線と
蒸着方向のなす角度である。なお、入射面は、法線と蒸
着方向を含む面と定義する。First, as an example, cobalt, which is a ferromagnetic material, was obliquely deposited. As shown in FIG. 1, the oblique deposition was performed using cobalt as the deposition source 1 and incident on the surface of the substrate 2 at an incident angle θ = 70 °. Is the angle between the normal to the surface of the substrate 2 and the deposition direction. Note that the incident surface is defined as a surface including a normal line and a vapor deposition direction.
【００１３】基板２としては、ウレタンアクリレート５
０部、ポリエステルアクリレート４０部、ポリオールア
クリレート１０部からなる溶液を紫外線硬化させて作成
したものを用いた。そして、基板２として、表面が平坦
でなく、直線レリーフ回折格子を設けたものを用いた。
その格子は、表面にピッチ０．８μｍ、深さ約０．１５
μｍの直線レリーフ回折格子パターンである。As the substrate 2, urethane acrylate 5
A solution composed of 0 part, 40 parts of polyester acrylate, and 10 parts of polyol acrylate was prepared by ultraviolet curing. As the substrate 2, a substrate having a non-flat surface and provided with a linear relief diffraction grating was used.
The grating has a pitch of 0.8 μm and a depth of about 0.15 on the surface.
It is a linear relief diffraction grating pattern of μm.
【００１４】蒸着源１のるつぼとしては、Ａｌ2 Ｏ3 か
らなるものを用い、蒸着装置は、バッチ式電子ビーム
（ＥＢ）蒸着装置を用い、ＥＢ蒸着条件として、加速電
圧４ｋＶ、ビーム電流１００〜１２０ｍＡ、真空圧力
７．０×１０-5〜９．０×１０-5ｔｏｒｒ、成膜速度４
Å／ｓで、膜厚約１０００Åの蒸着を行った。As the crucible of the vapor deposition source 1, a crucible made of Al 2 O 3 is used. As the vapor deposition apparatus, a batch type electron beam (EB) vapor deposition apparatus is used. 120 mA, vacuum pressure 7.0 × 10 −5 to 9.0 × 10 −5 torr, deposition rate 4
At 蒸 着 / s, vapor deposition was performed with a film thickness of about 1000Å.
【００１５】なお、蒸着の際の基板２表面の直線回折格
子の方向（凸条、凹溝の方向）と入射面の間の角度αを
回折格子方向αとした。The angle α between the direction of the linear diffraction grating (the direction of the ridges and grooves) on the surface of the substrate 2 during vapor deposition and the incident surface was defined as the diffraction grating direction α.
【００１６】このような条件でコバルトを斜方蒸着して
得られた磁気記録媒体に磁場を、図２（ａ）及び（ｂ）
に模式的に示すように、基板２面（ｘ−ｙ平面に平行）
に沿って、入射面に平行（ｘ方向）、及び、入射面に垂
直（ｙ方向）に印加して、回折格子方向αとの関係で、
その保磁力Ｈｃ、飽和磁束Ｂｓ、残留磁束Ｂｒ、角形比
Ｒｓを測定したところ、次の表−１及び表−２のような
結果が得られた（図２中、基板２面の法線はｚ方向に選
ばれている。）。なお、測定機として振動試料型磁力計
（ＶＳＭ）を用い、外部磁界は１０ｋＯｅであった。A magnetic field is applied to the magnetic recording medium obtained by obliquely depositing cobalt under these conditions, and FIGS. 2 (a) and 2 (b).
As schematically shown in FIG. 2, the substrate 2 surface (parallel to the xy plane)
Along the plane of incidence (x-direction) and perpendicular to the plane of incidence (y-direction), with respect to the diffraction grating direction α,
When the coercive force Hc, the saturation magnetic flux Bs, the residual magnetic flux Br, and the squareness ratio Rs were measured, the results shown in the following Tables 1 and 2 were obtained (in FIG. 2, the normal to the substrate 2 surface is selected in the z-direction.) A vibrating sample magnetometer (VSM) was used as a measuring instrument, and the external magnetic field was 10 kOe.
【００１７】 [0017]
【００１８】 [0018]
【００１９】以上の結果を図示すると、表−１が対応す
る入射面に平行に磁場を印加した時の磁気特性は図３の
ようになり、表−２が対応する入射面に垂直に磁場を印
加した時の磁気特性は図４のようになる。The above results are shown in Table 1. The magnetic characteristics when a magnetic field is applied in parallel to the corresponding incident surface in Table-1 are as shown in FIG. 3, and the magnetic field is perpendicular to the corresponding incident surface in Table-2. The magnetic characteristics when applied are as shown in FIG.
【００２０】次に、第２の例について説明する。前述の
例と同様の条件で鉄を斜方蒸着した。その表−１、表−
２と同様な結果をそれぞれ次の表−３、表−４に示す。Next, a second example will be described. Iron was obliquely deposited under the same conditions as in the above example. Table-1 and Table-
Table 3 and Table 4 below show the same results as in Table 2, respectively.
【００２１】 [0021]
【００２２】 [0022]
【００２３】以上の結果を図示すると、表−３が対応す
る入射面に平行に磁場を印加した時の磁気特性は図５の
ようになり、表−４が対応する入射面に垂直に磁場を印
加した時の磁気特性は図６のようになる。The above results are shown in Table 3. Table 3 shows the magnetic characteristics when a magnetic field is applied in parallel to the corresponding incident surface, as shown in FIG. 5, and Table 4 shows the magnetic field perpendicular to the corresponding incident surface. The magnetic properties when applied are as shown in FIG.
【００２４】以上の例から、基板２表面に直線レリーフ
回折格子を設けて、強磁性体である金属又はその化合物
を斜方蒸着する際、蒸着入射面に対する回折格子の方向
が平行から垂直に変化するにつれて、磁場の方向が蒸着
基板面に沿いかつ蒸着入射面に平行である場合、例えば
保磁力Ｈｃはα＝３０°以上では急減し、その後はほぼ
一定となり、角形比Ｒｓは徐々に小さくなって、磁気記
録特性が落ちる。また、磁場の方向が蒸着基板面に沿い
かつ蒸着入射面に垂直な場合、今度は、保磁力Ｈｃは徐
々に小さくなるが、代わって、角形比Ｒｓは徐々に大き
くなることが分る。From the above example, when a linear relief diffraction grating is provided on the surface of the substrate 2 and a metal or a compound thereof, which is a ferromagnetic material, is obliquely deposited, the direction of the diffraction grating with respect to the deposition entrance surface changes from parallel to perpendicular. When the direction of the magnetic field is along the surface of the deposition substrate and parallel to the deposition entrance surface, for example, the coercive force Hc suddenly decreases at α = 30 ° or more, becomes substantially constant thereafter, and the squareness ratio Rs gradually decreases. As a result, the magnetic recording characteristics deteriorate. When the direction of the magnetic field is along the surface of the deposition substrate and perpendicular to the deposition entrance surface, the coercive force Hc gradually decreases, but the squareness ratio Rs gradually increases instead.
【００２５】このように、斜方蒸着入射面に対するレリ
ーフ回折格子の方向によって磁気特性が変化するのは、
簡単に次のように説明できる。As described above, the magnetic characteristics change depending on the direction of the relief diffraction grating with respect to the oblique deposition entrance surface because:
It can be easily explained as follows.
【００２６】よく知られているように、斜方蒸着におい
ては、入射角が大きくなるにつれて磁気異方性が増大す
るため、蒸着基板面に沿いかつ蒸着入射面に平行な方向
では、保磁力、角形比が共に増大する傾向を示し、逆
に、蒸着基板面に沿いかつ蒸着入射面に垂直な方向では
これらが低下する傾向を示す。As is well known, in the oblique deposition, the magnetic anisotropy increases as the incident angle increases, so that the coercive force, Both the squareness ratios tend to increase, and conversely, they tend to decrease in the direction along the deposition substrate surface and perpendicular to the deposition incidence surface.
【００２７】ところで、例えば図２に示すように、蒸着
基板２表面にレリーフ回折格子が設けられている場合、
その格子の方向αが小さく格子の凸条及び凹溝が入射面
にほぼ平行であると、堆積膜厚の多い凸条及び凹溝の頂
上と谷底の部分では、入射角がほぼθであるのに対し、
凸条及び凹溝の斜面部分では、入射角がθより大きくな
るため、全体の磁気特性は、格子無しのものと比べ、同
等もしくは入射角が大きい場合と同様な特性を示す。こ
れとは反対に、回折格子の方向αがほぼ９０°になる
と、格子の凸条及び凹溝が入射面にほぼ垂直になり、凸
条及び凹溝の斜面部分に対する実際の入射角は実効的に
より小さくなり、したがって、全体の磁気特性は、入射
角がより小さい場合と同様な特性を示すことになる。By the way, as shown in FIG. 2, for example, when a relief diffraction grating is provided on the surface of the vapor deposition substrate 2,
When the direction α of the lattice is small and the ridges and grooves of the lattice are almost parallel to the incident surface, the incident angle is almost θ at the top and valley bottoms of the ridges and grooves whose deposition thickness is large. Against
At the slopes of the ridges and grooves, the angle of incidence is larger than θ, so that the overall magnetic properties are the same or similar to those without the grating when the angle of incidence is large. Conversely, when the direction α of the diffraction grating is approximately 90 °, the ridges and grooves of the grating become substantially perpendicular to the incident surface, and the actual angle of incidence of the ridges and grooves with respect to the slope is effective. And thus the overall magnetic properties will be similar to those at smaller angles of incidence.
【００２８】したがって、例えば、回折格子方向αを入
射面方向にとる場合、入射面に平行に磁場をかけるとす
ると、従来の方法で斜方蒸着する場合より、高保磁力の
媒体を得ることができる。また、回折格子方向αを入射
面に垂直にとる場合、入射面に垂直に磁場をかけるとす
ると、この方向での角形比が大きくなる。Therefore, for example, when the diffraction grating direction α is set in the direction of the incident surface, if a magnetic field is applied in parallel to the incident surface, a medium having a higher coercive force can be obtained than in the case of oblique deposition by the conventional method. . When the diffraction grating direction α is perpendicular to the incident surface, if a magnetic field is applied perpendicular to the incident surface, the squareness ratio in this direction increases.
【００２９】ところで、基板２上に一様なレリーフ回折
格子を設けるのではなく、例えば図７に示すように、予
め基板２の位置に応じて格子の方向αを部分的に変化さ
せて基板２表面を形成し、その表面全体に一様に斜方蒸
着して磁気記録媒体３を構成すると、図７の場合は、記
録、読み取り磁場方向を入射面に平行に選び、外部印加
磁界１３００Ｏｅで一定の周波数の情報を記録し、その
記録情報を読み取ると、図７に出力電圧を示すように、
格子方向αによって変調された情報を読み出すことがで
きる。さらに、基板２表面の格子方向の変化に対応して
保磁力が変化するため、例えば入射面に平行に外部印加
磁界５００Ｏｅで一定周波数の情報を記録し、同方向で
その記録情報を読み取ると、図７のように、高保磁力の
部分には記録されていないことが分かる。したがって、
外部印加磁界の設定により媒体３のこのようなレリーフ
回折格子パターンの格子方向分布に対応した出力電圧パ
ターンを磁気的に認識することができる。この場合、記
録された情報を消去して新たに別の情報を記録しようと
しても、蒸着方向と記録磁場方向の関係及び設定された
外部印加磁界の大きさが分からなければ、元の記録と同
様な記録をすることは容易でない。Instead of providing a uniform relief diffraction grating on the substrate 2, for example, as shown in FIG. When the magnetic recording medium 3 is formed by forming a surface and uniformly obliquely vapor-depositing the entire surface, in the case of FIG. 7, the recording and reading magnetic field directions are selected in parallel to the incident surface, and the direction is fixed by an externally applied magnetic field of 1300 Oe. When the information of the frequency is recorded and the recorded information is read, as shown in FIG.
Information modulated by the lattice direction α can be read. Further, since the coercive force changes in accordance with the change in the lattice direction of the surface of the substrate 2, for example, information of a constant frequency is recorded in parallel with the incident surface with an externally applied magnetic field of 500 Oe, and the recorded information is read in the same direction. As shown in FIG. 7, it is found that no information is recorded in the high coercive force portion. Therefore,
By setting the externally applied magnetic field, an output voltage pattern corresponding to the grating direction distribution of such a relief diffraction grating pattern on the medium 3 can be magnetically recognized. In this case, even if the recorded information is erased and new information is newly recorded, if the relationship between the deposition direction and the recording magnetic field direction and the magnitude of the set externally applied magnetic field are unknown, the same as the original recording is performed. It is not easy to keep a good record.
【００３０】本発明に用いられる強磁性体である金属又
はその化合物としては、Ｆｅ、Ｃｏ、Ｎｉ、Ｆｅ−Ｃ
ｏ、Ｆｅ−Ｃｒ、Ｆｅ−Ｖ、Ｆｅ−Ｎｉ、Ｆｅ−Ｐｔ、
Ｆｅ−Ｐｄ、Ｆｅ−Ｃｕ、Ｆｅ−Ｚｎ、Ｃｏ−Ｎｉ、Ｃ
ｏ−Ｃｒ、Ｃｏ−Ｖ、Ｃｏ−Ｃｕ、Ｃｏ−Ｍｎ、Ｃｏ−
Ｐ、Ｎｉ−Ｃｒ、Ｎｉ−Ｃｕ、Ｎｉ−Ｚｎ、Ｎｉ−Ｖ、
Ｎｉ−Ｍｎ、Ｆｅ−Ｃｏ−Ｎｉ、Ｆｅ−Ｍｎ−Ｃｏ、Ｆ
ｅ−Ｎｉ−Ｃｒ、Ｆｅ−Ｎｉ−Ｍｎ、Ｆｅ−Ｃｏ−Ｃ
ｒ、Ｃｏ−Ｍｎ−Ｎｉ、Ｃｏ−Ｎｉ−Ｐ、γ−Ｆｅ2 Ｏ
3 、Ｆｅ3 Ｏ4 、ＣｒＯ2 、あるいはこれらの混合物か
らなる群から選択することができる。Examples of the ferromagnetic metal or its compound used in the present invention include Fe, Co, Ni, and Fe—C.
o, Fe-Cr, Fe-V, Fe-Ni, Fe-Pt,
Fe-Pd, Fe-Cu, Fe-Zn, Co-Ni, C
o-Cr, Co-V, Co-Cu, Co-Mn, Co-
P, Ni-Cr, Ni-Cu, Ni-Zn, Ni-V,
Ni-Mn, Fe-Co-Ni, Fe-Mn-Co, F
e-Ni-Cr, Fe-Ni-Mn, Fe-Co-C
r, Co-Mn-Ni, Co-Ni-P, γ-Fe 2 O
3 , Fe 3 O 4 , CrO 2 , or a mixture thereof.
【００３１】また、蒸着基板２の表面の隣り合う凸条の
間隔であるピッチ幅は、強磁性体である金属の微粒子の
大きさが３００〜５００Åであることから、１０００Å
以上であれば、蒸着時の微粒子の結晶の成長に微小凹凸
パターンが影響を及ぼすことができるため望ましい。さ
らに、３０００Å以上のピッチ幅であれば、微小凹凸パ
ターンの斜面部分による斜方蒸着の入射角の増大の度合
を制御することができるため、より好ましい。The pitch width, which is the distance between adjacent ridges on the surface of the vapor deposition substrate 2, is 1000 ° because the size of the fine metal particles of a ferromagnetic material is 300 to 500 °.
Above-mentioned is preferable because the fine uneven pattern can affect the growth of the fine particle crystal during the vapor deposition. Further, a pitch width of 3000 ° or more is more preferable because the degree of increase in the incident angle of oblique vapor deposition due to the slope portion of the fine uneven pattern can be controlled.
【００３２】しかしながら、このような媒体３を磁気的
のみで記録、読み取りをする場合、その情報のセキュリ
ティ性は完全であるとは言い難い。そこで、本発明にお
いては、このような磁気的情報記録読み取りに加えて、
レリーフ回折格子パターンの分布を光学的に読み取り、
光学的読み取り情報と磁気的読み取り情報をリンケージ
させて記録のセキュリティ性を高めることにする。However, when such a medium 3 is recorded and read only magnetically, the security of the information cannot be said to be perfect. Therefore, in the present invention, in addition to such magnetic information recording and reading,
Optically reading the distribution of the relief diffraction grating pattern,
The optically read information and the magnetically read information are linked to enhance the security of recording.
【００３３】図８は、図７に示したような記録媒体３を
光学的及び磁気的に同時に読み取る装置の概略の配置を
示すもので、矢印方向に送られる媒体３上に、その方向
の磁場を読み取る磁気ヘッド４を配置して、外部印加磁
界１３００Ｏｅ、一定周波数で記録された媒体３の磁気
情報を読み取ると、図７の１３００Ｏｅの場合の出力電
圧に示すような信号が得られる。一方、磁気ヘッド４近
傍に発光素子５を配置し、それからの光が媒体３の回折
格子に入射するようにする。そして、各方向の回折格子
からの回折光が入射する位置に光検出器〜を配置す
ると、媒体３の回折格子の向きに対応して図７の検出器
の欄に示した検出器に回折光が入射し、媒体３の回折格
子の方向に対応した情報が光学的に読み取られる。した
がって、磁気ヘッド４からの出力信号強度と回折光検出
位置とを一対一に対応させることにより、エラーなく記
録媒体３を読み取ることができる。図７の１３００Ｏｅ
の場合は、磁気信号が最も強い位置と回折光検出位置が
ない場合、２番目に磁気信号強度が高い位置と回折光検
出器、３番目に磁気信号強度が高い位置と回折光検出
器、最も弱い磁気信号強度位置と回折光検出器がそ
れぞれ対応して読み取られれば、その媒体３の記録は真
実で改竄されていないものと判断できる。FIG. 8 shows a schematic arrangement of a device for simultaneously reading the recording medium 3 optically and magnetically as shown in FIG. 7, in which a magnetic field in that direction is placed on the medium 3 sent in the direction of the arrow. When a magnetic head 4 for reading is read and magnetic information of the medium 3 recorded at a constant frequency with an externally applied magnetic field of 1300 Oe is read, a signal as shown in the output voltage of 1300 Oe in FIG. 7 is obtained. On the other hand, the light emitting element 5 is arranged near the magnetic head 4 so that light from the light emitting element 5 is incident on the diffraction grating of the medium 3. When the photodetectors are arranged at positions where the diffracted light from the diffraction grating in each direction is incident, the diffracted light is applied to the detector shown in the column of the detector in FIG. And information corresponding to the direction of the diffraction grating of the medium 3 is optically read. Therefore, by associating the output signal intensity from the magnetic head 4 with the diffracted light detection position on a one-to-one basis, the recording medium 3 can be read without error. 1300 Oe in FIG.
In the case of, if there is no position where the magnetic signal is strongest and there is no diffracted light detection position, the position where the magnetic signal intensity is the second highest and the diffracted light detector, If the weak magnetic signal intensity position and the diffracted light detector are read correspondingly, it can be determined that the recording on the medium 3 is true and has not been tampered with.
【００３４】以上のようなレリーフ回折格子パターンと
強磁性体である金属又はその化合物の斜方蒸着を組み合
わせた光学的磁気的記録媒体の特徴をまとると、次のよ
うになる。The characteristics of an optical magnetic recording medium obtained by combining the above-described relief diffraction grating pattern with oblique deposition of a metal or a compound thereof as a ferromagnetic material are summarized as follows.
【００３５】（１）従来の回折格子を用いた光学的記録
媒体では、光学的情報を１つの読み取りシステムでしか
読めなかったが、本発明においては、光学的情報と一対
一対応の磁気的情報として磁気ヘッドで読むことができ
るので、記録媒体のセキュリティ性、認証性がさらに向
上する。(1) In a conventional optical recording medium using a diffraction grating, optical information can be read by only one reading system. However, in the present invention, magnetic information corresponding to optical information in a one-to-one correspondence. Can be read by a magnetic head, so that the security and authentication of the recording medium are further improved.
【００３６】（２）従来のものでは、光学情報と磁気情
報が別々の異なる位置に記録されていたが、本発明にお
いては、光学情報と磁気情報が同一部分に記録されてい
るので、どちらか一方を改竄しようとしても、もう一方
が破壊されてしまい、偽造が困難である。(2) In the prior art, optical information and magnetic information were recorded at different and different positions. However, in the present invention, since optical information and magnetic information are recorded in the same part, If one tries to falsify, the other is destroyed, making it difficult to forge.
【００３７】（３）従来のホログラム用いた光学的記録
媒体では、目視又は光学的な認証だけであるが、本発明
においては、さらに磁気情報が含まれており、一見した
だけでは従来のものと変わらないにもかかわらず、より
セキュリティ性が高い。(3) In a conventional optical recording medium using a hologram, only visual or optical authentication is performed. However, in the present invention, magnetic information is further included. Despite unchanged, more secure.
【００３８】（４）従来のものでは、回析格子のレリー
フ形状を簡単に複製できたが、本発明においては、レリ
ーフ形状を複製しようとしても、斜方蒸着によって形状
が変化しており、複製しても本来の光学情報と違ってし
まい、変造が困難である。(4) In the prior art, the relief shape of the diffraction grating could be easily duplicated. However, in the present invention, even if an attempt was made to duplicate the relief shape, the shape was changed by oblique vapor deposition. Even if it is different from the original optical information, it is difficult to forge.
【００３９】（５）従来の磁気記録媒体は、磁気情報の
書き換えが可能であるが、本発明のものにおいては、磁
気による書き換えが困難なので、固有データを記録する
ことができる。(5) The conventional magnetic recording medium is capable of rewriting magnetic information, but in the case of the present invention, rewriting by magnetism is difficult, so that unique data can be recorded.
【００４０】以上、本発明の光学的磁気的情報記録読み
取り方法及び光学的磁気的記録媒体について、実施例に
基づいて説明してきたが、本発明はこれら実施例に限定
されず、種々の変形が可能である。Although the optical magnetic information recording / reading method and the optical magnetic recording medium of the present invention have been described based on the embodiments, the present invention is not limited to these embodiments, and various modifications may be made. It is possible.
【００４１】[0041]
【発明の効果】以上の説明から明らかなように、本発明
の光学的磁気的情報記録読み取り方法及び光学的磁気的
記録媒体によると、格子の向きに分布を有するレリーフ
回折格子パターンを表面に有する基板のレリーフ面に強
磁性体である金属又はその化合物を斜方蒸着して形成し
た記録媒体に磁気記録をし、その磁気記録を読み取ると
共に、レリーフ回折格子パターンを光学的に読み取るの
で、光学的情報と一対一対応の磁気的情報を同時に記録
読み出しができ、記録媒体のセキュリティ性、認証性を
さらに向上させることができる。また、何れかの情報を
改竄しようとしても、他方の情報が破壊されてしまい、
偽造が困難となる。As is apparent from the above description, according to the optical / magnetic information recording / reading method and the optical / magnetic recording medium of the present invention, the surface has a relief diffraction grating pattern having a distribution in the direction of the grating. Magnetic recording is performed on a recording medium formed by obliquely depositing a ferromagnetic metal or a compound thereof on the relief surface of the substrate, and the magnetic recording is read and the relief diffraction grating pattern is read optically, so that optical The information and the magnetic information in one-to-one correspondence can be simultaneously recorded and read, and the security and the authenticity of the recording medium can be further improved. Also, if you try to falsify any information, the other information will be destroyed,
Forgery becomes difficult.
【図１】斜方蒸着を説明するための図である。FIG. 1 is a diagram for explaining oblique deposition.
【図２】磁気記録媒体の回折格子方向、蒸着入射方向、
磁場方向の関係を模式的に示す図である。FIG. 2 shows a diffraction grating direction of a magnetic recording medium, a deposition incidence direction,
It is a figure which shows the relationship of a magnetic field direction typically.
【図３】蒸着入射面に平行に磁場を印加した時の１例の
磁気特性を示す図である。FIG. 3 is a diagram showing magnetic properties of an example when a magnetic field is applied in parallel to a deposition entrance surface.
【図４】蒸着実施例の入射面に垂直に磁場を印加した時
の１例の磁気特性を示す図である。FIG. 4 is a diagram illustrating magnetic properties of an example when a magnetic field is applied perpendicularly to an incident surface in a vapor deposition example.
【図５】蒸着入射面に平行に磁場を印加した時の他の例
の磁気特性を示す図である。FIG. 5 is a diagram illustrating magnetic properties of another example when a magnetic field is applied in parallel to a deposition entrance surface.
【図６】蒸着実施例の入射面に垂直に磁場を印加した時
の他の例の磁気特性を示す図である。FIG. 6 is a diagram illustrating magnetic properties of another example when a magnetic field is applied perpendicularly to the incident surface in the vapor deposition example.
【図７】本発明の１実施例の記録媒体と磁気的読み取り
出力電圧及び光学的読み出し検出器の関係を説明するた
めの図である。FIG. 7 is a diagram for explaining the relationship between a recording medium, a magnetic read output voltage, and an optical read detector according to one embodiment of the present invention.
【図８】本発明による記録媒体を光学的及び磁気的に同
時に読み取る装置の１実施例の概略の配置を示す図であ
る。FIG. 8 is a diagram showing a schematic arrangement of an embodiment of an apparatus for reading a recording medium optically and magnetically simultaneously according to the present invention.
１…蒸着源 ２…基板 ３…記録媒体 ４…磁気ヘッド ５…発光素子 〜…光検出器 DESCRIPTION OF SYMBOLS 1 ... Evaporation source 2 ... Substrate 3 ... Recording medium 4 ... Magnetic head 5 ... Light emitting element -... Photodetector
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｇ１１Ｂ 5/80 Ｇ０６Ｋ 19/00 Ｆ (58)調査した分野(Int.Cl.7，ＤＢ名) G11B 13/04 B42D 15/10 G06K 7/00 - 7/14 G06K 19/00 - 19/18 G11B 5/80 G11B 5/85 ──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. 7 identification code FI G11B 5/80 G06K 19/00 F (58) Field surveyed (Int.Cl. 7 , DB name) G11B 13/04 B42D 15 / 10 G06K 7/00-7/14 G06K 19/00-19/18 G11B 5/80 G11B 5/85
Claims (3)
を有するレリーフ回折格子パターンを形成したものを用
い、そのレリーフ面に強磁性体である金属及びその化合
物を斜方蒸着して形成した記録媒体に磁気記録をし、そ
の磁気記録を読み取ると共に、レリーフ回折格子パター
ンを光学的に読み取ることを特徴とする光学的磁気的情
報記録読み取り方法。1. A recording method in which a substrate having a relief diffraction grating pattern having a distribution in the direction of a grating formed on a surface thereof is formed by obliquely depositing a metal or a compound thereof as a ferromagnetic material on the relief surface. An optical magnetic information recording / reading method comprising: performing magnetic recording on a medium; reading the magnetic recording; and optically reading a relief diffraction grating pattern.
いて記録情報の真実性を判定することを特徴とする請求
項１記載の光学的磁気的情報記録読み取り方法。2. The optical magnetic information recording / reading method according to claim 1, wherein the authenticity of the recorded information is determined based on the read magnetic information and optical information.
格子パターンを表面に有する基板のレリーフ面に強磁性
体である金属及びその化合物を斜方蒸着して形成した光
学的磁気的記録媒体。3. An optical / magnetic recording medium formed by obliquely depositing a ferromagnetic metal and a compound thereof on a relief surface of a substrate having a relief diffraction grating pattern having a distribution in the direction of the grating on the surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00033593A JP3165270B2 (en) | 1993-01-05 | 1993-01-05 | Optical magnetic information recording / reading method and optical magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00033593A JP3165270B2 (en) | 1993-01-05 | 1993-01-05 | Optical magnetic information recording / reading method and optical magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06203421A JPH06203421A (en) | 1994-07-22 |
| JP3165270B2 true JP3165270B2 (en) | 2001-05-14 |
Family
ID=11471024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00033593A Expired - Lifetime JP3165270B2 (en) | 1993-01-05 | 1993-01-05 | Optical magnetic information recording / reading method and optical magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3165270B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4627767B2 (en) * | 2007-04-19 | 2011-02-09 | 大日本印刷株式会社 | Information recording medium |
-
1993
- 1993-01-05 JP JP00033593A patent/JP3165270B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06203421A (en) | 1994-07-22 |
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