JPH05139081A - Card type optical recording medium and its manufacture - Google Patents
Card type optical recording medium and its manufactureInfo
- Publication number
- JPH05139081A JPH05139081A JP3331190A JP33119091A JPH05139081A JP H05139081 A JPH05139081 A JP H05139081A JP 3331190 A JP3331190 A JP 3331190A JP 33119091 A JP33119091 A JP 33119091A JP H05139081 A JPH05139081 A JP H05139081A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- recording
- liquid crystal
- recording medium
- type optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Credit Cards Or The Like (AREA)
- Thermal Transfer Or Thermal Recording In General (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
- Manufacturing Optical Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、高分子液晶（ＬＣＰ）
からなる記録層を有し、光照射により情報の記録、消去
を可逆的に行うカード型光記録媒体およびその製造方法
に関する。FIELD OF THE INVENTION The present invention relates to a polymer liquid crystal (LCP).
The present invention relates to a card type optical recording medium which has a recording layer made of, and which reversibly records and erases information by irradiation with light, and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】近年、情報を熱エネルギーの形で印加
し、記録材料の形状変化や物性変化として記録するいわ
ゆるヒートモード記録システムが実用化されつつある。
このようなヒートモード記録媒体としては、Ｔｅ、Ｂ
ｉ、Ｓｅ、Ｔｂ、Ｉｎなどを主成分とする金属材料を用
いた無機系の記録媒体、あるいはシアニンなどのポリメ
チン系色素、フタロシアニン、ナフタロシアニン、ポル
フィリンなどの大環状アザアヌレン系色素、ナフトキノ
ン、アントラキノン系色素およびジチオール金属錯体系
色素などの有機色素を用いた記録媒体が知られている。
これらの記録媒体は集光したレーザー光の照射などによ
り熱エネルギーが印加して、照射部分の記録層を溶融あ
るいは蒸発して孔(ピット)を形成し、情報を記録するも
のである。しかし、これらの記録媒体は記録した情報を
消去して再び新しい情報を記録する可能性を有していな
い。2. Description of the Related Art In recent years, a so-called heat mode recording system has been put into practical use in which information is applied in the form of thermal energy and recorded as a change in shape or a change in physical properties of a recording material.
As such a heat mode recording medium, Te, B
An inorganic recording medium using a metal material containing i, Se, Tb, In, etc. as a main component, or a polymethine dye such as cyanine, a macrocyclic azaannulene dye such as phthalocyanine, naphthalocyanine, and porphyrin, naphthoquinone, anthraquinone Recording media using organic dyes such as dyes and dithiol metal complex dyes are known.
Thermal energy is applied to these recording media by irradiation of condensed laser light, etc., and the recording layer in the irradiated area is melted or evaporated to form holes (pits), and information is recorded. However, these recording media have no possibility of erasing recorded information and recording new information again.
【０００３】これに対して、記録、再生、消去が可能な
可逆記録媒体として、たとえばＧｄ、Ｔｂ、Ｄｙなどの
希土類金属とＦｅ、Ｎｉ、Ｃｏなどの遷移金属とからな
る合金薄膜を用いた光磁気記録媒体が挙げられる。しか
し、この光磁気記録媒体は再生時の感度が低く、Ｓ／Ｎ
比が悪く、さらに酸化などの影響による記録感度の劣化
や記録の保存安定性に問題があるなどの欠点を有してい
る。On the other hand, as a reversible recording medium capable of recording, reproducing and erasing, light using an alloy thin film made of a rare earth metal such as Gd, Tb or Dy and a transition metal such as Fe, Ni or Co is used. A magnetic recording medium may be used. However, this magneto-optical recording medium has a low sensitivity at the time of reproduction,
The ratio is poor, and further, there are drawbacks such as deterioration of recording sensitivity due to the influence of oxidation and a problem in storage stability of recording.
【０００４】一方、有機材料を用いた可逆記録媒体とし
て、V.P. Shibaev et al.著、Polymer Communication
s、第２４巻、第３６３〜３６５頁、１９８３年や特開
昭５８−１２５２４７号公報等には、高分子液晶の透明
な配向状態と不透明な非配向状態を用いて、熱または電
界によって可逆的に変化させる記録媒体が開示されてい
る。On the other hand, as a reversible recording medium using an organic material, VP Shibaev et al., Polymer Communication
S., Vol. 24, pp. 363-365, 1983, JP-A-58-125247, and the like, using a transparent alignment state and an opaque non-alignment state of a polymer liquid crystal, reversible by heat or an electric field. A recording medium that is changed dynamically is disclosed.
【０００５】この光記録媒体の応用例の１つとして、近
年光カードが注目されている。これは磁気カードを中心
としたカードの発光枚数が飛躍的に増大し、かつ極めて
多岐に渡る分野で使用されているという社会的背景か
ら、大容量、高信頼性を特徴とする次世代型メディアの
１つとして脚光を浴びているためである。この光カード
システムには、これまで種々の報告が成されており、例
えばUSP4,278,756やUSP4,284,716等には銀塩等を記録層
として用いた、いわゆる再生専用または追記型光カード
が報告されているが、これらは可逆記録の可能性を全く
有してはいない。上記の高分子液晶を用いたカード型記
録媒体としては、例えば、特開昭６３−５１１９３号公
報に開示されたものがり、ここでは高分子液晶層を表示
部として用いているが、消去については検討されていな
い。また、特開昭６３−２８４２９１号公報や特開昭６
４−７０５８４号公報等には強誘電性高分子液晶（ＦＬ
ＣＰ）を用いた光カードの応用が例示されているが、低
分子の強誘電性液晶を用いたものと較べて特に変化は無
く、さらに光記録システムとして検討した場合、電界あ
るいは磁界を印加する機構は、システム構成上及びコス
ト的に明らかに不利であり、実用には至ってはいない。As one of the application examples of this optical recording medium, an optical card has been attracting attention in recent years. This is a next-generation medium characterized by high capacity and high reliability from the social background that the number of cards that emit light, such as magnetic cards, has dramatically increased and is used in a wide variety of fields. This is because it is in the spotlight as one of the above. Various reports have been made on this optical card system, for example, USP4,278,756 and USP4,284,716, etc., which are so-called read-only or write-once optical cards using a silver salt as a recording layer. However, they have no possibility of reversible recording. As a card type recording medium using the above-mentioned polymer liquid crystal, for example, one disclosed in JP-A-63-51193, in which a polymer liquid crystal layer is used as a display section, Not considered. In addition, JP-A-63-284291 and JP-A-6-264291.
No. 4,70,584 discloses a ferroelectric polymer liquid crystal (FL).
Although the application of the optical card using CP) is illustrated, there is no particular change compared to the one using a low molecular ferroelectric liquid crystal, and when examined as an optical recording system, an electric field or magnetic field is applied. The mechanism is clearly disadvantageous in terms of system configuration and cost, and has not been put to practical use.
【０００６】[0006]
【発明が解決しようとする課題】また従来の高分子液晶
を用いた可逆記録システムは、記録、消去の転送速度や
信頼性など種々の問題を残している。とりわけ消去速度
の高速化や消え残りの無い信頼性の高い消去が行なわれ
ることが望まれており、上記強誘電性を示す高分子液晶
を用いた記録媒体では、レスポンス的にも誘電異方性が
正のものを使用する例が多いため、その配向方向は記録
膜面に対して垂直方向に配向する（ホメオトロピック配
向）成分が強くなる。しかし、液晶部位の配向方向スイ
ッチングによる二状態の複屈折の差よりも、配向−未配
向状態の複屈折の差の方が大きくなることは公知であ
り、さらにシステムが量産性およびコスト的な問題から
光源と一対の偏光板等からなるオルソスコープで構成さ
れる点等を考慮しても、記録層材料には記録膜面に平行
に配向（ホモジニアス配向）する方が容易に高Ｓ／Ｎ比
を得られることは明らかである。しかるに上記強誘電性
高分子液晶で誘電異方性が負のものを用いると、ホモジ
ニアス配向性が現れるが、その応答性は通常の高分子液
晶と比較しても大差なく、かえってその構造が特殊であ
るためにコスト的にも不利であり、実用には供しえなか
った。The conventional reversible recording system using a polymer liquid crystal has various problems such as transfer speed and reliability of recording and erasing. In particular, it is desired that the erasing speed be increased and reliable erasure without remaining unerased be performed. In the recording medium using the polymer liquid crystal exhibiting the ferroelectric property, the dielectric anisotropy is also provided in response. Since there are many cases in which the positive polarity is used, the orientation direction has a strong component (homeotropic orientation) oriented in the direction perpendicular to the recording film surface. However, it is well known that the difference in birefringence between the orientation and the non-orientation state is larger than the difference in birefringence between the two states due to the switching of the orientation direction of the liquid crystal portion. Considering the fact that the recording layer material is composed of an orthoscope consisting of a light source and a pair of polarizing plates, etc., it is easier to orient the recording layer material parallel to the recording film surface (homogeneous orientation). It is clear that However, when the above ferroelectric polymer liquid crystal with negative dielectric anisotropy is used, homogeneous orientation appears, but its response is not much different from that of ordinary polymer liquid crystal, and its structure is rather special. Therefore, it is disadvantageous in terms of cost and could not be put to practical use.
【０００７】本発明は上記事情に鑑み、ホモジニアス配
向性のサーモトロピック高分子液晶を用いた高分子液晶
可逆記録層を用いて、高Ｓ／Ｎ比を維持しながら信頼性
の高い消去性能を示し、かつ低コストなカード型光記録
媒体を提供することを目的とする。In view of the above circumstances, the present invention shows a reliable erasing performance while maintaining a high S / N ratio by using a polymer liquid crystal reversible recording layer using a homogeneously aligned thermotropic polymer liquid crystal. It is also an object of the present invention to provide a low cost card type optical recording medium.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、上記の目
的に対して、電界、磁界を必要とせずに光照射により発
生する熱エネルギーのみにより、高分子液晶層が可逆的
に変化する記録、消去の各条件を検討し、記録時および
消去時の光ビームの照射条件を適切に選択することによ
り、上記の目的が達成できることを見出した。Means for Solving the Problems To solve the above problems, the present inventors reversibly change a polymer liquid crystal layer only by thermal energy generated by light irradiation without the need for an electric field or a magnetic field. It was found that the above-mentioned object can be achieved by examining each condition of recording and erasing, and by appropriately selecting the irradiation condition of the light beam at the time of recording and erasing.
【０００９】すなわち、本発明によれば、少なくともプ
ラスチック基板上に耐熱性樹脂層、照射光を吸収して熱
に変換する光熱変換層、高分子液晶配向層および可逆的
な配向状態の変化または相変化を起こして記録、消去を
行う高分子液晶からなる記録層を順次積層した構造を持
ち、該記録層は短時間の光照射によりその厚さ方向の一
部分の配向状態または相状態が変化するものであること
を特徴とするカード型光記録媒体が提供される。That is, according to the present invention, at least a heat-resistant resin layer on a plastic substrate, a photothermal conversion layer that absorbs irradiation light and converts it into heat, a polymer liquid crystal alignment layer, and a reversible alignment state change or phase. Having a structure in which recording layers made of polymer liquid crystal that undergo changes to perform recording and erasing are sequentially stacked, and the orientation state or phase state of a part of the recording layer changes in the thickness direction by light irradiation for a short time. A card type optical recording medium is provided.
【００１０】また、本発明によれば、上記構成において
記録層を構成する高分子液晶の初期配向状態の膜厚方向
の複屈折率と膜厚の積（リターデーション）が２５〜７
５０ｎｍの範囲であり、かつ該記録層はその記録前の透
過または反射偏光強度Ｉb が記録後の透過または反射偏
光強度Ｉa よりも小さくなるように記録が形成されるも
のであることを特徴とするカード型光記録媒体が提供さ
れる。この記録媒体を用いた場合、当該記録層の膜厚方
向のリターデーション変化に起因する再生光量の変化が
記録前よりも記録後の方が増加するような記録を行い、
かつ当該記録ピットを外力を印加せずに完全に消去せし
める記録、消去を行うことができる。Further, according to the present invention, the product (retardation) of the birefringence in the film thickness direction and the film thickness (retardation) in the initial alignment state of the polymer liquid crystal constituting the recording layer in the above structure is 25 to 7.
It is in the range of 50 nm, and the recording layer is characterized in that recording is formed such that the transmitted or reflected polarized light intensity Ib before recording is smaller than the transmitted or reflected polarized light intensity Ia after recording. A card type optical recording medium is provided. When this recording medium is used, recording is performed so that the change in the reproduction light amount due to the retardation change in the film thickness direction of the recording layer increases after recording as compared with before recording,
In addition, it is possible to perform recording and erasing so that the recording pit can be completely erased without applying an external force.
【００１１】また、本発明によれば、上記カード型光記
録媒体の製造方法であって、耐熱性樹脂層を一次基板と
してその上に光熱変換層、高分子液晶配向層及び記録層
を順次形成した後に、これとプラスチック基板とを貼着
することからなるカード型光記録媒体の製造方法が提供
される。Further, according to the present invention, there is provided the above method for producing a card type optical recording medium, wherein a heat-resistant resin layer is used as a primary substrate and a photothermal conversion layer, a polymer liquid crystal alignment layer and a recording layer are sequentially formed thereon. After that, a method for manufacturing a card type optical recording medium is provided, which comprises sticking this to a plastic substrate.
【００１２】さらに、本発明によれば、上記製造方法に
おいて、更に、記録層を耐熱性樹脂層でラミネートした
後に、別個のプラスチック基板または保護層を設ける工
程を具備することを特徴とするカード型光記録媒体の製
造方法が提供される。Further, according to the present invention, in the above manufacturing method, the method further comprises a step of providing a separate plastic substrate or protective layer after laminating the recording layer with the heat resistant resin layer. A method of manufacturing an optical recording medium is provided.
【００１３】以下に本発明を図面に基づいて詳細に説明
する。本発明によるカード型光記録媒体の基本構成は図
１に示したように、プラスチック基板１上に、耐熱性樹
脂層２、光熱変換層３、高分子液晶配向層４および高分
子液晶からなる記録層５を順に積層したものである。耐
熱性樹脂層２は当該カード型光記録媒体の製造をする際
に高温下での処理工程が含まれる場合があるため、一次
基板として用いるものである。光熱変換層３は記録時お
よび再生時に照射光を吸収して熱に変換するとともに、
再生時には照射光を反射する機能を兼ね備えたものであ
る。高分子液晶配向層４は記録層５の構成材料である高
分子液晶をホモジニアス配向せしめるものである。記録
層５は光照射により可逆的な配向状態の変化または相変
化を起こして記録、消去を行うものである。The present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the basic structure of the card type optical recording medium according to the present invention is a recording comprising a heat resistant resin layer 2, a photothermal conversion layer 3, a polymer liquid crystal alignment layer 4 and a polymer liquid crystal on a plastic substrate 1. The layer 5 is laminated in order. The heat-resistant resin layer 2 is used as a primary substrate because a treatment step at high temperature may be included in the production of the card type optical recording medium. The photothermal conversion layer 3 absorbs irradiation light during recording and reproduction and converts it into heat, and
It also has a function of reflecting irradiation light during reproduction. The polymer liquid crystal alignment layer 4 is for aligning the polymer liquid crystal which is a constituent material of the recording layer 5 homogeneously. The recording layer 5 is for recording and erasing by reversibly changing the orientation state or the phase change by light irradiation.
【００１４】本発明のカード型光記録媒体は図１に示す
ものに限定されるものではなく、種々の変形、変更が可
能である。例えば、図１の媒体の記録層５の上に耐熱性
樹脂層を再度形成して当該記録媒体全体をラミネートし
て保護層を兼務させた構造、あるいはその上に新たに基
板材料を貼り付けて保護層６を形成した構造（図２）等
にすることができる。The card type optical recording medium of the present invention is not limited to that shown in FIG. 1, but various modifications and changes can be made. For example, a structure in which a heat-resistant resin layer is formed again on the recording layer 5 of the medium in FIG. 1 and the entire recording medium is laminated to serve also as a protective layer, or a new substrate material is attached onto the structure. The structure (FIG. 2) in which the protective layer 6 is formed can be used.
【００１５】記録は、フォーカスされたビーム光を該光
記録媒体に照射して行なわれる。すなわち、光熱変換層
３にて吸収された光が熱に変換され、この熱が配向層４
を経由して記録層５に伝播し、記録層５の一部の温度を
等方相転移温度（アイソトロピック点）以上に加熱し、
その後光照射を打ち切り急冷させることにより、記録層
５内に等方性部分が形成される。このような記録を達成
するためには、光照射時に図３のような温度分布が記録
層５に形成される必要がある。この時に光照射を打ち切
るとアイソトロピック点以上に加熱された部分は、冷却
後この等方性状態が保持され、偏光光学的に異なる状態
となり、記録ピットが形成される。Recording is carried out by irradiating the optical recording medium with focused beam light. That is, the light absorbed in the photothermal conversion layer 3 is converted into heat, and this heat is transferred to the alignment layer 4
Propagates to the recording layer 5 via the, and heats part of the temperature of the recording layer 5 to an isotropic phase transition temperature (isotropic point) or higher,
Then, the light irradiation is stopped and the material is rapidly cooled to form an isotropic portion in the recording layer 5. In order to achieve such recording, it is necessary that the temperature distribution as shown in FIG. At this time, when the light irradiation is stopped, the portion heated above the isotropic point retains this isotropic state after cooling and becomes a polarization-optically different state, and a recording pit is formed.
【００１６】本発明における記録ピットの大きさの制御
とは、記録光の照射条件よって記録ピットの大きさを制
御することであり、具体的には図４に示したような記録
光強度差によって（ａ）（ｂ）の二状態を形成すること
をいう。つまり、記録ビーム光の強度が小さい場合は
（ａ）のように記録ピットは記録層５内の光熱変換層３
近傍に形成されるが、強度が大きい場合は（ｂ）に示し
たように記録ピットが（ａ）よりも大きく形成され、膜
厚方向の偏光の光路長が、未記録部＞図４の（ａ）の状
態の部分＞図１の（ｂ）の状態の部分の順に短くなるこ
とを意味する。この時にクロスニコル下で偏光の透過光
または反射光量の変化を検出して、情報の再生を行なう
ことができる。既報によると、リターデーションＲと再
生光量Ｉとの関係は次式（１）で表わされる。 Ｉ＝Ｉ0sin2(πR/λ) ・・・・・ (1) ここで、Ｉ0 は照射光強度、λは照射光波長である。ま
たＲ＝△ｎ・ｄで、△ｎは複屈折率、ｄは光路長であ
る。The control of the size of the recording pit in the present invention is to control the size of the recording pit according to the irradiation condition of the recording light, and concretely, the recording light intensity difference as shown in FIG. It means to form two states of (a) and (b). That is, when the intensity of the recording beam light is low, the recording pits are formed in the recording layer 5 as shown in FIG.
Although formed in the vicinity, when the strength is high, the recording pit is formed larger than that in (a) as shown in (b), and the optical path length of polarized light in the film thickness direction is unrecorded> It means that the portion in the state of a)> the portion in the state of FIG. At this time, it is possible to reproduce information by detecting a change in the amount of transmitted light or reflected light of polarized light under crossed Nicols. According to a previous report, the relationship between the retardation R and the reproduction light amount I is expressed by the following equation (1). I = I 0 sin 2 (πR / λ) (1) where I 0 is the irradiation light intensity and λ is the irradiation light wavelength. Further, R = Δn · d, Δn is the birefringence, and d is the optical path length.
【００１７】本発明者らはこの点について検討を行な
い、当該記録層５のリターデーションＲを２５〜７５０
ｎｍという範囲に制御すると、上記記録状態を達成し、
かつ未記録状態よりも記録後の方が大きな偏光透過率を
有する上に、さらに該記録ピットが光照射のみによって
完全に消去可能であることを見出し、本発明を完成する
に至った。記録層の膜厚は、本記録媒体の層構成にも関
連するが、反射型媒体ではおよそ０．５〜２．５μｍの
範囲が好ましく、また透過型媒体の場合はその２倍程度
の膜厚が好ましい。さらに複屈折率は高分子液晶のメソ
ーゲン部位の構造及び配向状態にも起因するために一概
に特定はしにくいが、およそ０．０５〜０．３の範囲が
好適である。The present inventors have examined this point and set the retardation R of the recording layer 5 to 25 to 750.
When controlled in the range of nm, the above recording state is achieved,
Moreover, they have found that the recording pit has a larger polarized light transmittance after recording than that in an unrecorded state and that the recording pit can be completely erased only by irradiation with light, and thus the present invention has been completed. Although the film thickness of the recording layer is related to the layer structure of the present recording medium, it is preferably in the range of about 0.5 to 2.5 μm for the reflective medium, and about twice that for the transmissive medium. Is preferred. Further, the birefringence index is difficult to be specified unconditionally because it depends on the structure and alignment state of the mesogenic moiety of the polymer liquid crystal, but a range of about 0.05 to 0.3 is preferable.
【００１８】また、本発明においていう短時間の光照射
による記録とは、当該記録媒体に照射するビーム光の走
査を１点当たりの露光時間が数ｍｓ以下となるような速
度で走査することをいい、さらに具体的には数十μｓ以
下であることが望ましい。露光時間が数ｎｓ以下と極端
に短い場合は記録層５は等方相転移温度以上に加熱され
ず、記録ピットは形成されない。また時間が極端に長い
場合は等方相転移温度以上に加熱された部分が拡散し、
全膜厚が等方性状態となるために、容易に消去できなく
なる。In the present invention, the recording by light irradiation for a short time means that the light beam irradiated on the recording medium is scanned at a speed such that the exposure time per point is several ms or less. More specifically, it is desirable that it is several tens of μs or less. When the exposure time is extremely short, such as several ns or less, the recording layer 5 is not heated above the isotropic phase transition temperature, and no recording pit is formed. Also, if the time is extremely long, the portion heated above the isotropic phase transition temperature will diffuse,
Since the entire film thickness is isotropic, it cannot be easily erased.
【００１９】本発明の記録媒体における記録の消去は、
等方性状態で保持された記録ピットを再加熱し、ピット
を含む微小領域の粘度を低下せしめて、領域内の分子が
分子運動できる状態にしたときに、周囲の配向している
高分子液晶分子及び配向層から配向規制力を受けて、ラ
ンダム状態の高分子液晶分子が再配向することによって
達成される。この分子再配向が起こる温度はアイソトロ
ピック点以下の数℃〜数十℃が好適であるが、消え残り
の無い完全な消去を行なうためには、少なくとも記録ピ
ット全体がこの温度範囲に入るように加熱する必要があ
る。これに対して記録時は記録層の一部分だけを変化さ
せた方が消去し易いために、強いレーザー光を用いて短
時間露光により、記録層の一部をアイソトロピック点以
上に加熱すれば達成されるため、記録層内の温度分布は
膜厚方向で急激に変化している方が望ましい。しかし消
去時は緩やかな温度変化が起きる方が好ましく、弱い強
度のレーザー光を比較的長時間照射することによって達
成される。この時例えば記録時と同じ照射時間で強度の
みを弱くすると、記録ピット全体を均一に加熱すること
ができず、また照射時間のみを長くすると、膜厚方向の
深部までが高い温度に加熱され結局再記録される。The erasure of records on the recording medium of the present invention is
When the recording pits held in the isotropic state are reheated to reduce the viscosity of the minute area including the pits and the molecules in the area are allowed to move, the polymer liquid crystal in the surrounding orientation. This is achieved by realigning the polymer liquid crystal molecules in a random state by receiving the alignment control force from the molecules and the alignment layer. The temperature at which this molecular reorientation occurs is preferably several degrees Celsius to several tens of degrees Celsius below the isotropic point, but at least the entire recording pit should be in this temperature range for complete erasing without erasure. It needs to be heated. On the other hand, when recording, it is easier to erase by changing only a part of the recording layer, so it is achieved by heating a part of the recording layer above the isotropic point by short-time exposure using a strong laser beam. Therefore, it is desirable that the temperature distribution in the recording layer changes rapidly in the film thickness direction. However, it is preferable that a gradual temperature change occurs during erasing, and this can be achieved by irradiating a laser beam of weak intensity for a relatively long time. At this time, for example, if only the intensity is weakened during the same irradiation time as during recording, the entire recording pit cannot be heated uniformly, and if the irradiation time alone is lengthened, the deep part in the film thickness direction is heated to a high temperature. It will be re-recorded.
【００２０】次に本発明の記録媒体の基板１の構成材料
について説明すると、この基板材料には種々の公知材料
が使用できるが、カードの携帯性を考慮すると、各種プ
ラスチック基板が最も好適であり、具体的にはポリエチ
レン、ポリプロピレン、ポリスチレン、ポリ塩化ビニ
ル、ポリカーボネート、ポリビニルアルコール、ポリビ
ニルアセテート、ポリアミド、ポリイミド、ポリオレフ
ィン、アクリル樹脂、フェノール樹脂、エポキシ樹脂、
フッ素系樹脂及び上記の誘導体等を利用することが可能
である。Next, the constituent materials of the substrate 1 of the recording medium of the present invention will be explained. Although various known materials can be used as the substrate material, various plastic substrates are most suitable in consideration of portability of the card. , Specifically, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, polyvinyl acetate, polyamide, polyimide, polyolefin, acrylic resin, phenol resin, epoxy resin,
It is possible to use a fluororesin and the above-mentioned derivatives.
【００２１】ところで、本発明の記録媒体を作製する過
程で、高分子液晶配向処理時あるいは配向層形成時にお
いて、１００℃またはそれ以上の温度域で数十分以上処
理する工程が出現する可能性がある。このような場合、
上記の基板材料の中でもポイリイミド、エポキシ樹脂、
あるいはフッ素系樹脂等の極く限られたものしか利用す
ることはできず、反面これらの基板材料は複屈折や照射
光透過率が余り高くないために、膜厚では利用し難いの
が現状である。By the way, in the process of producing the recording medium of the present invention, a step of treating several tens of minutes or more at a temperature range of 100 ° C. or higher may appear during the alignment treatment of the polymer liquid crystal or the formation of the alignment layer. There is. In such cases,
Among the above substrate materials, polyimide, epoxy resin,
Alternatively, it is possible to use only a very limited material such as a fluorine-based resin, but on the other hand, since these substrate materials do not have a very high birefringence and irradiation light transmittance, it is difficult to use the film thickness at present. is there.
【００２２】そこで、本発明者らは、耐熱性樹脂層２を
一次基板とし、この上に光熱変換層３、高分子配向層
４、記録層５の各層を形成した後に、プラスチック基板
１と貼り合せることによって、当該カード型記録媒体を
作製する方式を採用した。これにより、作製されたカー
ド型光記録媒体が高信頼性のものとなる。Therefore, the present inventors have used the heat-resistant resin layer 2 as a primary substrate, and after forming the respective layers of the photothermal conversion layer 3, the polymer alignment layer 4 and the recording layer 5 on this, they are bonded to the plastic substrate 1. A method for producing the card-type recording medium was adopted by combining them. As a result, the produced card type optical recording medium becomes highly reliable.
【００２３】耐熱性樹脂層２としてはポリイミド、エポ
キシ樹脂、フッ素樹脂等の材料が使用可能で、膜厚は１
〜５０μｍが適当である。Materials such as polyimide, epoxy resin, and fluororesin can be used for the heat resistant resin layer 2, and the film thickness is 1
-50 μm is suitable.
【００２４】本発明において記録層５に用いられる高分
子液晶は公知のものが利用できるが、メソーゲン部位を
主鎖ないし側鎖に有し、平均分子量が５００以上のもの
が利用できる。又、当該高分子液晶は架橋されているも
のであっても良く、光架橋型であればなお好ましい。Known polymer liquid crystals can be used for the recording layer 5 in the present invention, but those having a mesogen moiety in the main chain or side chain and an average molecular weight of 500 or more can be used. Further, the polymer liquid crystal may be crosslinked, and more preferably a photocrosslinking type.
【００２５】以下に本発明で用いる高分子液晶の具体例
を挙げるが、以下において＊は不斉炭素原子であること
を示す。Specific examples of the polymer liquid crystal used in the present invention will be given below. In the following, * indicates an asymmetric carbon atom.
【００２６】[0026]
【表１】 [Table 1]
【００２７】[0027]
【表２】 [Table 2]
【００２８】[0028]
【表３】 [Table 3]
【００２９】[0029]
【表４】 [Table 4]
【００３０】[0030]
【表５】 [Table 5]
【００３１】[0031]
【表６】 [Table 6]
【００３２】[0032]
【表７】 [Table 7]
【００３３】[0033]
【表８】 [Table 8]
【００３４】[0034]
【表９】 [Table 9]
【００３５】[0035]
【表１０】 [Table 10]
【００３６】[0036]
【表１１】 [Table 11]
【００３７】[0037]
【表１２】 [Table 12]
【００３８】このような高分子液晶は通常単独ないし混
合して使用され、更に他の低分子液晶を加えて使用する
ことも可能である。ここで添加される低分子液晶は高分
子液晶の粘度、相転移温度等をコントロールして、記録
特性及び消去特性の改善を目的とするもので、ネマチッ
クやスメクチックあるいはコレステリック液晶で公知の
ものが利用できる。Such polymer liquid crystals are usually used alone or as a mixture, and it is also possible to add other low-molecular liquid crystals. The low-molecular liquid crystal added here is for improving the recording property and the erasing property by controlling the viscosity and phase transition temperature of the high-molecular liquid crystal, and a known nematic, smectic or cholesteric liquid crystal is used. it can.
【００３９】このような高分子液晶を使用して、例えば
メチルエチルケトン、メチルイソブチルケトン、シクロ
ヘキサノン等のケトン系、酢酸ブチル、酢酸エチル、酢
酸メチル、カルビトールアセテート、ブチルカルビトー
ルアセテート等のエステル系、メチルセロソルブ、エチ
ルセロソルブ、テトラヒドロフラン等のエーテル系、な
いしトルエン、キシレン等の芳香族系、ジクロロエタン
等のハロゲン化アルキル系、Ｎ，Ｎ−ジメチルホルムア
ミド、Ｎ−Ｎ−ジメチルアセトアミド、アルコール系等
溶液に溶解して、例えば、ディップコーティング、スプ
レーコーティング、スピナーコーティング、ブレードコ
ーティング、ローラコーティング、カーテンコーティン
グ、ワイアーコーティング等の溶液塗布法や場合によっ
ては加熱による融液状態から塗布して形成することが可
能である。By using such a polymer liquid crystal, for example, a ketone system such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc., an ester system such as butyl acetate, ethyl acetate, methyl acetate, carbitol acetate, butyl carbitol acetate, methyl, etc. Dissolve in ether type such as cellosolve, ethyl cellosolve, tetrahydrofuran, aromatic type such as toluene or xylene, halogenated alkyl type such as dichloroethane, N, N-dimethylformamide, N-N-dimethylacetamide, alcohol type, etc. For example, solution coating methods such as dip coating, spray coating, spinner coating, blade coating, roller coating, curtain coating, wire coating, and in some cases melting by heating. It can be formed by coating from the state.
【００４０】本発明で用いられる光熱変換層３を形成す
る材料には公知のものを利用できるが、具体的には、例
えば、金、白金、銀、銅、鉛、亜鉛、アルミニウム、ニ
ッケル、タンタル、コバルト、クロム、ゲルマニウム、
ニオブ、パラジウム、スズ等の各種金属、半金属の蒸
着、ＣＶＤ、スパッタリング膜などが挙げられる。ま
た、光熱変換層３は再生時等に照射光の一部を反射する
反射層として兼用することができる。Known materials can be used as the material for forming the photothermal conversion layer 3 used in the present invention. Specifically, for example, gold, platinum, silver, copper, lead, zinc, aluminum, nickel, tantalum. , Cobalt, chromium, germanium,
Examples include various metals such as niobium, palladium, and tin, vapor deposition of semimetals, CVD, and sputtering films. Further, the photothermal conversion layer 3 can also serve as a reflection layer that reflects a part of the irradiation light during reproduction or the like.
【００４１】また、配向層４の材料としては公知の材料
が利用できるが、具体的にはポリイミドあるいはその前
駆体であるポリアミック酸などにラビング処理を施した
ものや、シリコン酸化物等を斜方蒸着したものなどが使
用できる。Known materials can be used as the material of the alignment layer 4. Specifically, polyimide or polyamic acid which is a precursor thereof is subjected to a rubbing treatment, or silicon oxide or the like is oblique. A vapor-deposited product can be used.
【００４２】[0042]
【実施例】以下に本発明を実施例を挙げて説明するが、
本発明はこれら実施例のみに限定されるものではない。EXAMPLES The present invention will be described below with reference to examples.
The invention is not limited to these examples only.
【００４３】実施例１ 厚さ３０μｍのポリイミドフィルムをＷ３５ｍｍ×Ｄ７
０ｍｍにカットし、一次基板２として用いた。当該一次
基板５上に図５で示したように長手方向へパターニング
しながら、クロム膜を１０００Å厚に蒸着し、光熱変換
層３を形成した。当該光熱変換層３はトラッキング及び
フォーカシング用グループを兼ねるため、ピッチ２０μ
ｍ、幅１０μｍで蒸着した。この上に角度６０°で基板
の長手方向に対して酸化シリコンを針方蒸着し配向層４
を形成した後、前記Ｎｏ．３３（表５）の高分子液晶を
テトラヒドロフラン中に約１０ｗｔ％溶解した溶液を用
いて、前記配向層４上に厚さ１．６μｍの記録層５を形
成した。このサンプルをオーブン中で約１７０℃で３０
分間の配向処理を施した後、偏光顕微鏡観察にて観察し
たところ、当該記録層５が良好な配向をしていることを
確認した。次に、このサンプルの一次基板とポリカーボ
ネート基板（Ｗ５４ｍｍ×Ｄ８６ｍｍ×ｔ０．５５ｍ
ｍ）を紫外線硬化型樹脂を用いて接着し、さらに記録層
５上には同様にＷ５４ｍｍ×Ｄ８６ｍｍ×ｔ０．１５ｍ
ｍのアクリル樹脂板を貼り付け、保護層６を形成し、本
発明によるカード型光記録媒体を作製した。Example 1 A polyimide film having a thickness of 30 μm was formed into W35 mm × D7.
It was cut to 0 mm and used as the primary substrate 2. While patterning in the longitudinal direction on the primary substrate 5 as shown in FIG. 5, a chromium film was deposited to a thickness of 1000 Å to form the photothermal conversion layer 3. Since the photothermal conversion layer 3 also functions as a tracking and focusing group, the pitch is 20 μm.
m and the width was 10 μm. Alignment layer 4 was formed by depositing silicon oxide at a 60 ° angle with respect to the longitudinal direction of the substrate by needle vapor deposition.
After the formation of No. A recording layer 5 having a thickness of 1.6 μm was formed on the alignment layer 4 using a solution of the polymer liquid crystal of 33 (Table 5) dissolved in tetrahydrofuran in an amount of about 10 wt%. This sample is placed in an oven at about 170 ° C for 30
After performing the alignment treatment for a minute, it was confirmed by observation with a polarizing microscope that the recording layer 5 had a good orientation. Next, the primary substrate of this sample and the polycarbonate substrate (W54 mm × D86 mm × t0.55 m
m) is adhered using an ultraviolet curable resin, and W54 mm × D86 mm × t0.15 m is similarly formed on the recording layer 5.
An acrylic resin plate of m was attached to form a protective layer 6, and a card type optical recording medium according to the present invention was produced.
【００４４】次に、波長７８０ｍｍの半導体レーザーを
光源に用いて、これをφ５μｍに集光した後に、線速１
００ｍｍ／ｓ、強度１３ｍＷ、１０ｋＨｚ、デューティ
比５０％で本記録媒体の記録層を基板側から照射し、記
録を行なった。また、本記録媒体を用いて、先の半導体
レーザーとφ５μｍ集光用光学系を使用して、その光路
上に記録層入射前と反射後に各々直交する偏光板を設け
た。反射光は２枚目の偏光板の後にピンフォトダイオー
トにて光量を測定できるようなシステムを用い、レーザ
ー光強度をサンプル面上で３ｍＷまで落とし、線速２０
０ｍｍ／Ｓで先の記録部の再生を行なった。得られた応
答をフーリエ変換し、そのＣ／Ｎを測定したところ、少
なくとも３５ｄＢ以上のＣ／Ｎが得られることが確認さ
れた。Next, after using a semiconductor laser having a wavelength of 780 mm as a light source and converging it to φ5 μm, a linear velocity of 1
Recording was performed by irradiating the recording layer of the present recording medium from the substrate side at 00 mm / s, intensity of 13 mW, 10 kHz, and duty ratio of 50%. Further, using the present recording medium, the above-mentioned semiconductor laser and φ5 μm converging optical system were used, and polarizing plates orthogonal to each other were provided on the optical path thereof before incidence on the recording layer and after reflection. For the reflected light, a system capable of measuring the amount of light with a pin photo diauto after the second polarizing plate was used, the laser light intensity was reduced to 3 mW on the sample surface, and a linear velocity of 20
The recording portion was reproduced at 0 mm / S. It was confirmed that at least 35 dB or more of C / N was obtained by Fourier transforming the obtained response and measuring the C / N thereof.
【００４５】次に、本記録媒体に対して、記録時と同様
の操作で強度７ｍＷ、線速１ｍｍ／ＳでＣＷ（連続点
灯）で露光し、消去操作を行なった後、この記録媒体を
偏光顕微鏡で観察したところ、記録ピットが完全に消去
されていることが確認された。Next, the recording medium was exposed with CW (continuous lighting) at an intensity of 7 mW and a linear velocity of 1 mm / S by the same operation as during recording, and after erasing operation, the recording medium was polarized. Observation with a microscope confirmed that the recording pits were completely erased.
【００４６】[0046]
【発明の効果】本発明によれば、高分子液晶記録層の厚
さ方向の一部分の配向状態を変化させることにより記録
を行うために、記録時の転送速度を向上させるだけでな
く、記録時の変化部分が消去の際に元の状態に戻りやす
いため消し残りがなくかつ消去速度が高速化され、信頼
性の高い新規なカード型光記録媒体を提供することが可
能となる。According to the present invention, since recording is performed by changing the orientation state of a part of the polymer liquid crystal recording layer in the thickness direction, not only the transfer rate at the time of recording is improved but also recording is performed. It is possible to provide a novel card-type optical recording medium having high reliability because the changed portion of the data is likely to return to its original state upon erasing, there is no unerased portion, and the erasing speed is increased.
【図１】本発明のカード型光記録媒体の構造例を示す断
面図である。FIG. 1 is a cross-sectional view showing a structural example of a card type optical recording medium of the present invention.
【図２】本発明のカード型光記録媒体の別の構造例を示
す断面図である。FIG. 2 is a sectional view showing another structural example of the card type optical recording medium of the present invention.
【図３】記録層内に形成されるべき温度分布を示す断面
図である。FIG. 3 is a sectional view showing a temperature distribution to be formed in the recording layer.
【図４】記録ピットの大きさのコントロールの説明図で
ある。FIG. 4 is an explanatory diagram of controlling the size of a recording pit.
【図５】実施例における媒体の作製の説明図である。FIG. 5 is an explanatory diagram of manufacturing a medium in an example.
１ プラスチック基板 ２ 耐熱性樹脂層（一次基板） ３ 光熱変換層 ４ 高分子液晶配向層 ５ 記録層 1 Plastic Substrate 2 Heat Resistant Resin Layer (Primary Substrate) 3 Photothermal Conversion Layer 4 Polymer Liquid Crystal Alignment Layer 5 Recording Layer
Claims (4)
樹脂層、照射光を吸収して熱に変換する光熱変換層、高
分子液晶配向層および可逆的な配向状態の変化または相
変化を起こして記録、消去を行う高分子液晶からなる記
録層を順次積層した構造を持ち、該記録層は短時間の光
照射によりその厚さ方向の一部分の配向状態または相状
態が変化するものであることを特徴とするカード型光記
録媒体。1. A heat-resistant resin layer on at least a plastic substrate, a photothermal conversion layer that absorbs irradiation light and converts it into heat, a polymer liquid crystal alignment layer, and a reversible change in alignment state or phase change for recording. It has a structure in which recording layers composed of a polymer liquid crystal for erasing are sequentially laminated, and the recording layers are changed in a partial orientation state or phase state in the thickness direction by light irradiation for a short time. Card type optical recording medium.
向状態の膜厚方向の複屈折率と膜厚の積（リターデーシ
ョン）が２５〜７５０ｎｍの範囲であり、かつ該記録層
はその記録前の透過または反射偏光強度Ｉb が記録後の
透過または反射偏光強度Ｉa よりも小さくなるように記
録が形成されるものであることを特徴とする請求項１に
記載のカード型光記録媒体。2. The product (retardation) of the birefringence in the film thickness direction and the film thickness (retardation) in the initial alignment state of the polymer liquid crystal constituting the recording layer is in the range of 25 to 750 nm, and the recording layer is 2. The card type optical recording medium according to claim 1, wherein the recording is formed so that the transmitted or reflected polarized light intensity Ib before recording is smaller than the transmitted or reflected polarized light intensity Ia after recording.
録媒体であって、耐熱性樹脂層を一次基板としてその上
に光熱変換層、高分子液晶配向層及び記録層を順次形成
した後に、これとプラスチック基板とを貼着することか
らなるカード型光記録媒体の製造方法。3. The card type optical recording medium according to claim 1, wherein a heat-resistant resin layer is used as a primary substrate, and a photothermal conversion layer, a polymer liquid crystal alignment layer and a recording layer are sequentially formed thereon. , A method for manufacturing a card type optical recording medium, which comprises sticking this to a plastic substrate.
トした後に、別個のプラスチック基板または保護層を設
ける工程を具備することを特徴とする請求項３に記載の
カード型光記録媒体の製造方法。4. The production of a card type optical recording medium according to claim 3, further comprising the step of providing a separate plastic substrate or protective layer after laminating the recording layer with a heat resistant resin layer. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03331190A JP3080454B2 (en) | 1991-11-20 | 1991-11-20 | Card type optical recording medium and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03331190A JP3080454B2 (en) | 1991-11-20 | 1991-11-20 | Card type optical recording medium and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05139081A true JPH05139081A (en) | 1993-06-08 |
| JP3080454B2 JP3080454B2 (en) | 2000-08-28 |
Family
ID=18240896
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03331190A Expired - Lifetime JP3080454B2 (en) | 1991-11-20 | 1991-11-20 | Card type optical recording medium and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3080454B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3718957A1 (en) * | 1986-06-07 | 1987-12-10 | Victor Company Of Japan | MAGNETIC RECORDING MEDIA COMPRISING AT LEAST IN A MAGNETIC RECORDING LAYER A MODIFIED VINYL CHLORIDE RESIN |
| JPH08203140A (en) * | 1995-01-25 | 1996-08-09 | Toppan Printing Co Ltd | Information recording medium, information recording method and information recording device |
| JP2010201824A (en) * | 2009-03-04 | 2010-09-16 | Ricoh Co Ltd | Optical recording medium |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6074080B1 (en) * | 2016-02-10 | 2017-02-01 | 玲子 恩川 | How to use the multi-functional shirt |
-
1991
- 1991-11-20 JP JP03331190A patent/JP3080454B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3718957A1 (en) * | 1986-06-07 | 1987-12-10 | Victor Company Of Japan | MAGNETIC RECORDING MEDIA COMPRISING AT LEAST IN A MAGNETIC RECORDING LAYER A MODIFIED VINYL CHLORIDE RESIN |
| JPH08203140A (en) * | 1995-01-25 | 1996-08-09 | Toppan Printing Co Ltd | Information recording medium, information recording method and information recording device |
| JP2010201824A (en) * | 2009-03-04 | 2010-09-16 | Ricoh Co Ltd | Optical recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3080454B2 (en) | 2000-08-28 |
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