JPH04337524A - Optical recording and reproducing method - Google Patents
Optical recording and reproducing methodInfo
- Publication number
- JPH04337524A JPH04337524A JP3107388A JP10738891A JPH04337524A JP H04337524 A JPH04337524 A JP H04337524A JP 3107388 A JP3107388 A JP 3107388A JP 10738891 A JP10738891 A JP 10738891A JP H04337524 A JPH04337524 A JP H04337524A
- Authority
- JP
- Japan
- Prior art keywords
- light
- wavelength
- wavelength light
- rare earth
- optical recording
- 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
- 230000003287 optical effect Effects 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims description 16
- 230000005284 excitation Effects 0.000 claims abstract description 24
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 23
- 239000000463 material Substances 0.000 claims abstract description 21
- -1 rare earth ions Chemical class 0.000 abstract description 8
- 230000001681 protective effect Effects 0.000 abstract description 5
- 230000008832 photodamage Effects 0.000 abstract 1
- 229910052693 Europium Inorganic materials 0.000 description 7
- 229910001637 strontium fluoride Inorganic materials 0.000 description 7
- FVRNDBHWWSPNOM-UHFFFAOYSA-L strontium fluoride Chemical compound [F-].[F-].[Sr+2] FVRNDBHWWSPNOM-UHFFFAOYSA-L 0.000 description 7
- 229910052772 Samarium Inorganic materials 0.000 description 6
- 238000010521 absorption reaction Methods 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000000295 emission spectrum Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 229910001632 barium fluoride Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Landscapes
- Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
- Optical Recording Or Reproduction (AREA)
Abstract
Description
【0001】0001
【産業上の利用分野】本発明は光記録再生方法に係わる
。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording and reproducing method.
【0002】0002
【従来の技術】光を利用した情報記録の方法の一つとし
てフォトクロミズム現象を応用したものが知られている
。このような情報記録においては、幾つかの問題点があ
る。BACKGROUND OF THE INVENTION As one of the methods of recording information using light, one that applies the photochromism phenomenon is known. There are several problems with such information recording.
【0003】フォトクロミズムとは、或る光に対する物
質の吸収率が光照射によって変化する現象である。従っ
て、このような性質を持つ物質を情報記録媒体とし、或
る領域即ち情報記録ピットにおける吸収率の値が、或る
しきい値以上か、しきい値以下であるかを2値情報と対
応させて、その記録を行うことができる。通常のフォト
クロミズム現象を利用した情報記録方法はこの態様をと
るものである。[0003] Photochromism is a phenomenon in which the absorption rate of a substance for a certain light changes due to light irradiation. Therefore, a substance with such properties is used as an information recording medium, and whether the absorption rate value in a certain area, that is, an information recording pit, is above a certain threshold value or below a certain threshold value is corresponded to binary information. and record it. An ordinary information recording method using the photochromism phenomenon takes this form.
【0004】然し乍ら、この場合、そのフォトクロミズ
ム物質の吸収率変化を起こす、即ち、記録或いは消去を
行うためには、ある程度強い光を照射することが一般的
に必要である。However, in this case, in order to cause a change in the absorption rate of the photochromic material, that is, to perform recording or erasing, it is generally necessary to irradiate the photochromic material with a certain amount of strong light.
【0005】このため、繰り返しの記録、再生及び消去
の操作を行うと、記録媒体自体が光損傷を受ける恐れが
大で特性の変化を来たし、寿命に問題がある。[0005] For this reason, when repeated recording, reproducing, and erasing operations are performed, there is a high risk that the recording medium itself will be optically damaged, resulting in changes in characteristics and problems with its lifespan.
【0006】又、記録ないしは消去のために照射する光
の波長と、再生の際に用いる光即ち、その情報記録媒体
における光吸収率の変化を検出する光の波長とが接近し
ている場合には、その読み出しの際に記録又は消去の必
要のない部分を記録ないし消去してしまうなど信頼性及
びS/N(C/N)に問題がある。[0006] Furthermore, when the wavelength of the light irradiated for recording or erasing is close to the wavelength of the light used for reproduction, that is, the wavelength of the light used to detect changes in the light absorption rate in the information recording medium, has problems with reliability and signal-to-noise ratio (C/N), such as recording or erasing portions that do not need to be recorded or erased during reading.
【0007】[0007]
【発明が解決しようとする課題】本発明は、上述したフ
ォトクロミズム現象を利用した光記録再生方法において
、その光記録媒体の光損傷、したがって信頼性、更に再
生特性のS/N(C/N)の改善をはかる。Problems to be Solved by the Invention The present invention provides an optical recording and reproducing method that utilizes the above-mentioned photochromism phenomenon. We aim to improve this.
【0008】[0008]
【課題を解決するための手段】本発明においてはフォト
クロミズム現象を生じさせる光記録媒体として、特に希
土類元素が添加された無機フォトクロミック材料による
所定の電子状態で所定の波長発光を行うことのできるフ
ォトクロミック材料を光記録媒体として用いて、所定の
波長の発光によって記録の読み出しを行うことができる
ようにする。[Means for Solving the Problems] In the present invention, as an optical recording medium that causes a photochromism phenomenon, a photochromic material that can emit light at a predetermined wavelength in a predetermined electronic state using an inorganic photochromic material doped with a rare earth element is used. is used as an optical recording medium, and recording can be read out by emitting light of a predetermined wavelength.
【0009】即ち、本発明においては、希土類元素が添
加された無機フォトクロミック材料を有して成り、光記
録媒体を用いる。そして、この光記録媒体は、第1の波
長光励起によっても第2の波長光発光が得られない希土
類イオンの第1の電子状態と、第3の波長光照射による
光イオン化によって希土類元素の電子状態を変化させて
上記第1の波長光励起によって上記第2の波長光発光を
得る状態とする第2の電子状態とを採る。That is, in the present invention, an optical recording medium comprising an inorganic photochromic material doped with a rare earth element is used. In this optical recording medium, the first electronic state of the rare earth ion in which light emission at the second wavelength cannot be obtained even by excitation with light at the first wavelength, and the electronic state of the rare earth element by photoionization due to irradiation with light at the third wavelength. and a second electronic state in which light emission at the second wavelength is obtained by excitation with light at the first wavelength.
【0010】そしてこの光記録媒体に対し、上記第3の
波長光を記録光として上記第1及び第2の電子状態によ
って情報の記録をなし、第1の波長光を記録の読み出し
励起光として上記第2の波長光の発光の有無ないしは大
小によって上記記録の読み出しを行う。[0010] Information is then recorded on this optical recording medium using the third wavelength light as recording light according to the first and second electronic states, and the first wavelength light is used as the recording readout excitation light. The above-mentioned recording is read out depending on whether or not the second wavelength light is emitted.
【0011】また、他の本発明は、同様に、希土類元素
が添加された無機フォトクロミック材料を有して成る光
記録媒体を用いる。この光記録媒体は、第1の波長光励
起によっても第4の波長光発光が得られる希土類イオン
の第1の電子状態と、第3の波長光照射による光イオン
化によって希土類元素の電子状態を変化させて上記第1
の波長光励起によって上記第4の波長光発光が得られな
い状態とする第2の電子状態とを採る。Another aspect of the present invention similarly uses an optical recording medium comprising an inorganic photochromic material doped with a rare earth element. This optical recording medium has a first electronic state of a rare earth ion in which light emission at a fourth wavelength can also be obtained by excitation with light at a first wavelength, and an electronic state of a rare earth element that can be changed by photoionization by irradiation with light at a third wavelength. The above 1st
A second electronic state is adopted in which light emission at the fourth wavelength cannot be obtained by excitation with light at a wavelength of .
【0012】そしてこの光記録媒体に対し、上記第3の
波長光を記録光として上記第1及び第2の電子状態によ
って情報の記録をなし、上記第1の波長光を記録の読み
出し励起光として上記第4の波長光の発光の有無ないし
は大小によって上記記録の読み出しを行うことを特徴と
する光記録再生方法。[0012] Information is recorded on this optical recording medium using the third wavelength light as recording light according to the first and second electronic states, and the first wavelength light is used as recording readout excitation light. An optical recording and reproducing method characterized in that the recording is read out depending on the presence or absence or magnitude of emission of the fourth wavelength light.
【0013】[0013]
【作用】上述の本発明による光記録再生方法によれば、
その情報の読み出しは、或る波長の読み出し光を照射し
、これによって励起された他の波長の発光光を情報光と
して取り出すものであるので、冒頭に述べた従来のフォ
トクロミズム光記録方式におけるように吸収率の変化に
よって情報の読み出しを行う場合に比して再生出力が格
段に向上する。したがってS/N(C/N)の向上をは
かることができる。[Operation] According to the optical recording and reproducing method according to the present invention described above,
To read out the information, a readout light of a certain wavelength is irradiated, and the emitted light of another wavelength excited by this is extracted as information light. Therefore, as in the conventional photochromism optical recording method mentioned at the beginning, The reproduction output is significantly improved compared to the case where information is read by changing the absorption rate. Therefore, it is possible to improve the S/N (C/N).
【0014】又、読み出し光即ち励起光と、これによっ
て取り出した発光による情報光とが異なる波長であるた
めに、両者の分離が容易となり、光ピックアップ機構は
、光記録媒体に対して同一の片側から励起光の照射と情
報光の取り出しを行う簡易な構成を採ることができる。
つまり、例えば吸収率の変化を読み出す場合におけるよ
うに透過光によってその検出を行うべく、光記録媒体を
挟んで光源部と情報光の読み出し部とを配置する光ピッ
クアップ構成をとることがないのでその構造が極めて簡
潔化される。Furthermore, since the readout light, that is, the excitation light, and the information light emitted by the light emitted from the readout light have different wavelengths, it is easy to separate the two, and the optical pickup mechanism is mounted on the same side of the optical recording medium. It is possible to adopt a simple configuration in which excitation light is irradiated and information light is extracted from. In other words, in order to detect a change in absorption rate using transmitted light, for example, when reading out a change in absorption rate, there is no need to adopt an optical pickup configuration in which a light source section and an information light reading section are arranged with an optical recording medium in between. The structure is extremely simplified.
【0015】又、その記録、更に後述する消去のための
光強度は、この種の希土類を含む無機クロミック材料を
用いることによって、その光強度を差程高める必要がな
いことから光記録媒体に対し、繰り返しの記録消去を行
ってもその光損傷を充分小さくすることが出来、信頼性
の向上と、長寿命化をはかることができる。[0015] Furthermore, the light intensity for recording and erasing, which will be described later, does not need to be increased significantly by using this type of inorganic chromic material containing rare earth elements, so Even if repeated recording and erasing is performed, the optical damage caused by the recording and erasing can be sufficiently reduced, and reliability can be improved and the service life can be extended.
【0016】[0016]
【実施例】本発明による光記録再生方法に用いる光記録
媒体4は、図1にその略線的断面図を示すように、基体
1上に希土類元素が添加された無機フォトクロミック材
料を有して成る記録層2を被着し、これの上に必要に応
じて光反射膜或いは及びSiN、SiO2 等の保護膜
3が被着された構成とする。[Example] An optical recording medium 4 used in the optical recording and reproducing method according to the present invention has an inorganic photochromic material doped with a rare earth element on a substrate 1, as shown in a schematic cross-sectional view in FIG. A recording layer 2 consisting of the following materials is deposited, and a light reflecting film or a protective film 3 made of SiN, SiO2 or the like is deposited thereon as required.
【0017】基体1は、例えばガラス或いは例えば、P
C(ポリカーボネイト)等の光透過性樹脂等による光透
過性基板によって構成し得る。The substrate 1 is made of, for example, glass or, for example, P.
It can be constructed from a light-transparent substrate made of a light-transparent resin such as C (polycarbonate).
【0018】記録層2は、無機結晶、例えば金属の酸化
物、硫化物、ハロゲン化物等の母体に、希土類が数モル
%或いはそれ以下の1モル%程度ないしはそれ以下に添
加さたフォトクロミズム無機化合物材料を塗布或いは蒸
着、スパッター等によって被着形成してなる。The recording layer 2 is a photochromic inorganic compound in which a rare earth element is added to an inorganic crystal such as a metal oxide, sulfide, halide, etc. in an amount of about 1 mol % or less. The material is deposited by coating, vapor deposition, sputtering, or the like.
【0019】このフォトクロミック材料としては例えば
、SrF2 :Sm,Eu、或いはBaF2 :Sm,
Eu、またはSrS:Ce,Sm、ないしSrS:Eu
,Sm等を用い得る。Examples of this photochromic material include SrF2:Sm, Eu, or BaF2:Sm,
Eu, or SrS:Ce, Sm, or SrS:Eu
, Sm, etc. can be used.
【0020】実施例1この実施例では、図1に説明した
光記録媒体4において、そのフォトクロミック材料とし
てSrF2 :Sm,Euを用い、光反射型方式をもっ
て、その読み出しを行う場合である。Embodiment 1 In this embodiment, SrF2:Sm,Eu is used as the photochromic material in the optical recording medium 4 shown in FIG. 1, and reading is performed using a light reflection type method.
【0021】光記録媒体4の記録層2は、SrF2 の
母体に対してそれぞれ1モル%のSmとEuが添加され
たフォトクロミック材料SrF2 :Sm、Euによっ
て構成される。The recording layer 2 of the optical recording medium 4 is composed of a photochromic material SrF2:Sm, Eu to which 1 mol % of Sm and Eu are added to the SrF2 matrix.
【0022】この場合、図3に希土類イオンのエネルギ
ー準位を模式的に示すように、初期の状態では図3Aに
示すように、第1の波長λ1 =488nm波長光の励
起によっては、第2の波長λ2 =690nmの発光が
生じないエネルギー準位を示す希土類イオンの電子状態
、即ち3価のSmと、2価のEu状態にある第1の電子
状態にある。In this case, as shown schematically in FIG. 3, the energy level of the rare earth ion is as shown in FIG. 3A in the initial state. The electronic state of the rare earth ion exhibits an energy level at which no light emission at the wavelength λ2 = 690 nm occurs, that is, the first electronic state is the trivalent Sm state and the divalent Eu state.
【0023】この状態で図3Bに示すように、第3の波
長λ3 の光、即ち紫外線を照射すると、光イオン化に
より、Euから電子が1個脱離してSmに移動するため
、それぞれEuは3価、Smは2価になる。すなわち希
土類イオンのエネルギー準位が変化する。この状態で図
3Cに示すように、第1の波長λ1 =488nmの光
で励起を行うと、λ2 =690nmの2価のSmの発
光が生じる第2の電子状態となる。In this state, as shown in FIG. 3B, when light of the third wavelength λ3, that is, ultraviolet rays, is irradiated, one electron is desorbed from Eu and transferred to Sm due to photoionization, so that each Eu becomes 3 The valence, Sm, becomes divalent. That is, the energy level of the rare earth ion changes. In this state, as shown in FIG. 3C, when excitation is performed with light having a first wavelength λ1 = 488 nm, a second electronic state is created in which divalent Sm emission of λ2 = 690 nm occurs.
【0024】尚、この第2の電子状態において、第5の
波長λ5 の光を照射することによって再びSmを3価
に、Euを2価に戻せば、図3Aに示す第1の電子状態
に移行することができる。つまり初期化(消去)を行う
ことができる。In this second electronic state, if Sm is returned to trivalent state and Eu is returned to divalent state by irradiation with light of the fifth wavelength λ5, the first electronic state shown in FIG. 3A is achieved. can be migrated. In other words, initialization (erasing) can be performed.
【0025】したがって、この実施例1では、第3の波
長λ3 光、即ち紫外線を記録光として、これの照射の
オフ・オンによって図3Aに示す第1の電子状態と、図
3Cに示す第2の電子状態によって例えば“0”、“1
”の2値の情報の記録を行う。Therefore, in Example 1, the third wavelength λ3 light, that is, ultraviolet rays, is used as recording light, and the first electronic state shown in FIG. 3A and the second electronic state shown in FIG. 3C are created by turning off and on the irradiation. For example, “0”, “1” depending on the electronic state of
” is recorded.
【0026】そして、第1の波長λ1 =488nmの
光を読み出し光として照射し、これによる励起によって
第2の波長λ2 =690nmの発光の有無によって第
1の電子状態か、第2の電子状態か、つまり“0”“1
”の記録の読み出しを行うことができる。Then, light with a first wavelength λ1 = 488 nm is irradiated as readout light, and due to excitation by this, the state is changed to either the first electronic state or the second electronic state depending on whether or not light is emitted with a second wavelength λ2 = 690 nm. , that is, “0” “1”
” records can be read.
【0027】図4及び図5は第1及び第2の電子状態に
おけるSrF2 :Sm,Euの波長488nm(λ1
)の光励起による場合の発光スペクトル図を示す。こ
の場合、第1の電子状態では607nm程度の橙色の発
光が得られ、第2の電子状態では690nm程度の赤の
発光が生じることになる。FIGS. 4 and 5 show SrF2:Sm,Eu in the first and second electronic states at a wavelength of 488 nm (λ1
) shows an emission spectrum diagram when photoexcited. In this case, orange light emission of about 607 nm is obtained in the first electronic state, and red light emission of about 690 nm is obtained in the second electronic state.
【0028】この実施例1における記録、再生(読み出
し)及び消去は、例えば図2に示すように、光記録媒体
4の例えば光透過性基板1と対向する側に配置された少
なくとも光源部21と光検出部22とを有する光記録再
生手段によって行う。この場合、光源部21は、第1の
波長λ1 =488nmの光源と、第3の波長光の紫外
線光源と、第5の波長の消去光の光源を有して成る。Recording, reproduction (reading), and erasing in this embodiment 1 are performed using at least a light source section 21 disposed on the side of the optical recording medium 4 facing, for example, the light-transmitting substrate 1, as shown in FIG. This is performed by an optical recording/reproducing means having a photodetector section 22. In this case, the light source section 21 includes a light source with a first wavelength λ1 = 488 nm, an ultraviolet light source with a third wavelength, and a light source with erasing light with a fifth wavelength.
【0029】先ず、その記録にあたっては、第3の波長
λ3 光、この例においては、紫外線を記録情報に応じ
て、オン・オフ変調させて第1の電子状態から第2の電
子状態に変化させるか変化させないようにして“0”“
1”の記録を行う。First, for recording, the third wavelength λ3 light, in this example, ultraviolet light, is modulated on and off in accordance with the recording information to change from the first electronic state to the second electronic state. or “0” without changing it.
1” is recorded.
【0030】その読み出しに当たっては、第1の波長λ
1 =488nmの光を照射することによって光記録媒
体4の記録層2から第2の波長光λ2 =690nmの
発光を生じさせ、この赤の発光を、フィルタ、ないしは
この波長の光を反射させるミラー23によって分離して
光検出部22に導入してこの第2の波長λ2 の発光の
有無によって“0”“1”の情報の読み出しを行う。For reading, the first wavelength λ
By irradiating light of 1 = 488 nm, second wavelength light λ2 = 690 nm is emitted from the recording layer 2 of the optical recording medium 4, and this red emission is filtered or a mirror that reflects the light of this wavelength. 23 and introduced into the photodetecting section 22, and the information of "0" and "1" is read out depending on the presence or absence of light emission of this second wavelength λ2.
【0031】この場合、第1の波長の励起光λ1 =4
88nmと、第2の波長λ2 =690nmの光、即ち
情報光とはその波長に大きな差を有するために、確実に
励起光と分離してその光の検出を行うことができること
からS/N(C/N)の高い読み出しを行うことができ
る。In this case, the excitation light of the first wavelength λ1 = 4
Since there is a large difference in wavelength between light with a wavelength of 88 nm and light with a second wavelength λ2 = 690 nm, that is, information light, the light can be reliably separated from the excitation light and detected, so the S/N ( C/N) can be read.
【0032】光検出部22は例えばフォトダイオードに
よって構成し、その出力を増幅器によって増幅する。或
いは、光検出部22として光増倍管(フォトマルチプラ
イヤー)を用いることもできる。The photodetector 22 is constituted by, for example, a photodiode, and its output is amplified by an amplifier. Alternatively, a photomultiplier can also be used as the photodetector 22.
【0033】尚、上述した例では、光記録媒体4の基板
1側から光照射及び読み出しを行うようにした場合であ
るが、保護膜3側を透明とし基板1にAl等の反射面を
例えば記録層2の被着面側に形成し、保護膜3側から光
照射及び読み出しを行うこともできる。In the above example, light irradiation and reading are performed from the substrate 1 side of the optical recording medium 4, but the protective film 3 side is made transparent and the substrate 1 is coated with a reflective surface such as Al. It is also possible to form it on the adhering surface side of the recording layer 2 and perform light irradiation and reading from the protective film 3 side.
【0034】また、図2に示す例においては、光記録媒
体4に対して同一例から励起光即ち、第1の波長光照射
励起と、情報光即ち第2の波長光の検出を行うようにし
た場合であるが、これらを光記録媒体を挟んで、一方か
ら読み出し光の照射を行い他方から情報光を検出するこ
ともできる。In the example shown in FIG. 2, the optical recording medium 4 is irradiated with excitation light, that is, the first wavelength light, and detected with the information light, that is, the second wavelength light. However, it is also possible to sandwich them with an optical recording medium in between, irradiate readout light from one side, and detect information light from the other side.
【0035】実施例2上述の実施例1では、第2の電子
状態の有無、つまり第2の波長λ2 光を情報光とした
場合であるが、この実施例では第1の電子状態の有無、
つまり図4の第4の波長λ4 の光を情報光とする以外
は、実施例1と同様の記録再生方法を採る。Example 2 In Example 1 described above, the presence or absence of the second electronic state, that is, the case where the second wavelength λ2 light is used as information light, is the case, but in this example, the presence or absence of the first electronic state,
That is, the same recording and reproducing method as in the first embodiment is used except that the light having the fourth wavelength λ4 in FIG. 4 is used as the information light.
【0036】上述の構成において、光記録媒体のフォト
クロミック材料としては、一般に励起光波長λ3 が発
光波長λ2 、λ4 より小さいことが高い発光効率を
示すが、更に励起光即ち読み出し光と情報光を分離して
取り出す上では、できるだけλ3 <λ2 ,λ4 と
される。
又、λ3 <λ1 ,λ4 とすることによって再生時
(読み出し時)に記録が生じるような不都合が回避され
、いわゆる非破壊読み出しができる。また、λ5 <λ
1 とすることによって再生時の消去が回避される。In the above-described configuration, the photochromic material of the optical recording medium generally exhibits high luminous efficiency when the excitation light wavelength λ3 is smaller than the emission wavelengths λ2 and λ4. When extracting the signals, λ3 < λ2, λ4 is set as much as possible. Further, by setting λ3 <λ1, λ4, the inconvenience of recording during reproduction (reading) can be avoided, and so-called non-destructive reading can be performed. Also, λ5 <λ
1, erasure during playback can be avoided.
【0037】尚、上述した各フォトクロミック材料によ
る光記録媒体は、その特性が安定していて経時変化は認
められず、又、材料自体の光損傷も生じないことが確か
められた。It has been confirmed that the optical recording media made of each of the above-mentioned photochromic materials have stable characteristics and do not show any change over time, and do not cause optical damage to the materials themselves.
【発明の効果】上述したように本発明によれば、その光
記録即ち、情報の読み出しのための励起光、即ち第1の
波長λ1 光が、例えば“0”“1”の情報の記録を行
う書き込み波長、即ち第3の波長λ3 の光とは異なる
第1の波長光の励起によって行うので、この読み出しに
当たって、誤った記録がなされることが回避される。As described above, according to the present invention, the optical recording, that is, the excitation light for reading information, that is, the first wavelength λ1 light, can record information of, for example, "0" and "1". Since the excitation is performed using light of a first wavelength different from the writing wavelength, that is, the light of the third wavelength λ3, erroneous recording can be avoided during this reading.
【0038】又、情報光は、これを読み出しのための励
起光の第1の波長光λ1 とは異なる第2の波長λ2
の波長光或いは第4の波長λ4 光であるので、情報光
の分離を容易に行うことができる。したがってこれによ
って光記録媒体4に対して読み出し光等の光照射と情報
光とを同一側とすることができ、光ピックアップ手段と
しての構造の簡潔化をはかることができる。Further, the information light has a second wavelength λ2 different from the first wavelength light λ1 of the excitation light for reading out the information light.
or the fourth wavelength λ4 light, the information light can be easily separated. Therefore, the optical recording medium 4 can be irradiated with light such as read light and the information light on the same side, and the structure of the optical pickup means can be simplified.
【0039】また、λ2 及びλ4 の情報光は発光に
よるものであるので、再生出力が向上し、S/N(C/
N)の向上がはかられる。Furthermore, since the information lights of λ2 and λ4 are emitted, the reproduction output is improved and the S/N (C/N) is improved.
N) can be improved.
【図1】本発明による光記録再生方法に用いる光記録媒
体の一例の略線的拡大断面図である。FIG. 1 is a schematic enlarged cross-sectional view of an example of an optical recording medium used in the optical recording and reproducing method according to the present invention.
【図2】本発明による光記録再生方法の一例の略線的構
成図である。FIG. 2 is a schematic diagram of an example of the optical recording and reproducing method according to the present invention.
【図3】本発明の光記録再生方法の動作の説明に供する
希土類イオンのエネルギー準位図である。FIG. 3 is an energy level diagram of rare earth ions for explaining the operation of the optical recording and reproducing method of the present invention.
【図4】第1の電子状態のSrF2 :Sm、Euの発
光スペクトル図である。FIG. 4 is an emission spectrum diagram of SrF2:Sm, Eu in a first electronic state.
【図5】第2の電子状態のSrF2 :Sm、Euの発
光スペクトル図である。FIG. 5 is an emission spectrum diagram of SrF2:Sm, Eu in a second electronic state.
1 基体 2 記録層 3 保護膜 4 光記録媒体 21 光源部 22 光検出部 1 Base 2 Recording layer 3 Protective film 4 Optical recording medium 21 Light source section 22 Photo detection section
Claims (2)
ロミック材料を有して成り、第1の波長光励起によって
も第2の波長光発光が得られない希土類イオンの第1の
電子状態と、第3の波長光照射による光イオン化によっ
て上記希土類イオンの電子状態を変化させて上記第1の
波長光励起によって上記第2の波長光発光を得る状態と
する第2の電子状態とを採る光記録媒体を用い、上記第
3の波長光を記録光として上記第1及び第2の電子状態
によって情報の記録をなし、上記第1の波長光を記録の
読み出し励起光として上記第2の波長光の発光の有無な
いしは大小によって上記記録の読み出しを行うことを特
徴とする光記録再生方法。1. An inorganic photochromic material doped with a rare earth element, comprising a first electronic state of a rare earth ion in which light emission at a second wavelength cannot be obtained even by excitation with light at a first wavelength; Using an optical recording medium that adopts a second electronic state in which the electronic state of the rare earth ion is changed by photoionization by wavelength light irradiation and the second wavelength light emission is obtained by the first wavelength light excitation, The third wavelength light is used as recording light to record information according to the first and second electronic states, and the first wavelength light is used as recording readout excitation light to determine whether or not the second wavelength light is emitted. An optical recording and reproducing method characterized in that the above-mentioned recording is read out depending on the size.
ック材料を有して成り、第1の波長光励起によって第4
の波長光発光が得られる希土類イオンの第1の電子状態
と、第3の波長光照射による光イオン化によって上記希
土類イオンの電子状態を変化させて上記第1の波長光励
起によって上記第4の波長光発光が得られない状態とす
る第2の電子状態とを採る光記録媒体を用い、上記第3
の波長光を記録光として上記第1及び第2の電子状態に
よって情報の記録をなし、上記第1の波長光を記録の読
み出し励起光として上記第4の波長光の発光の有無ない
しは大小によって上記記録の読み出しを行うことを特徴
とする光記録再生方法。Claim 2: Comprised of an inorganic photochromic material doped with a rare earth element, the fourth photochromic material is
The electronic state of the rare earth ion is changed by photoionization by irradiation with a third wavelength light, and the fourth wavelength light is emitted by excitation with the first wavelength light. using an optical recording medium that adopts a second electronic state in which no light emission is obtained;
Information is recorded by using the wavelength light as recording light according to the first and second electronic states, and the first wavelength light is used as recording readout excitation light depending on the presence or absence or size of emission of the fourth wavelength light. An optical recording and reproducing method characterized by reading out recorded information.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3107388A JP2964692B2 (en) | 1991-05-13 | 1991-05-13 | Optical recording / reproducing method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3107388A JP2964692B2 (en) | 1991-05-13 | 1991-05-13 | Optical recording / reproducing method |
Publications (2)
Publication Number | Publication Date |
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JPH04337524A true JPH04337524A (en) | 1992-11-25 |
JP2964692B2 JP2964692B2 (en) | 1999-10-18 |
Family
ID=14457868
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JP3107388A Expired - Fee Related JP2964692B2 (en) | 1991-05-13 | 1991-05-13 | Optical recording / reproducing method |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001216649A (en) * | 2000-01-31 | 2001-08-10 | Central Glass Co Ltd | Three-dimensional optical memory medium and method for recording |
-
1991
- 1991-05-13 JP JP3107388A patent/JP2964692B2/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001216649A (en) * | 2000-01-31 | 2001-08-10 | Central Glass Co Ltd | Three-dimensional optical memory medium and method for recording |
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JP2964692B2 (en) | 1999-10-18 |
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