JP3829754B2 - Optical disk recording device - Google Patents

Description

【００２２】
【表２】

【００２３】
【表３】

【００２４】
【表４】

【００２５】
【表５】

表１〜５によれば、Ｋ値は、記録速度倍率をｘとすると、次式で近似できる。
【００２６】
シアニン系：Ｋ＝−０．１６ｘ＋１．２
フタロシアニン系：Ｋ＝−０．１５ｘ＋１．１５
また、各記録速度倍率においてターゲットβの値を様々に変えてシアニン系ディスクに記録したときの再生信号の３Ｔランドジッタ特性を図２０に示す。これによれば、記録速度倍率が高くなるほどターゲットβの値を低くした方がランドジッタが良好となることがわかる。各記録速度倍率ごとのターゲットβの最適な範囲を表６に示す（シアニン系ディスク、フタロシアニン系ディスクに共通に適用可能である。）。
【００２７】
【表６】

ターゲットβは記録深さに関係し、記録深さは記録時のレーザパワーで変わるから、ターゲットβは記録時のレーザパワー（トップパワー）Ｐｔで制御することができる。すなわち、レーザパワーＰｔを上げるとターゲットβの値は高くなり、レーザパワーＰｔを下げるとターゲットβの値は低くなる。したがって、最適なターゲットβの値（表６）が得られるレーザパワーＰｔの値を予め求めて、実際の記録時の記録速度倍率に応じて、該当するレーザパワーＰｔに制御して記録を行うことにより、いずれの記録速度倍率で記録した時でも、再生信号の波形歪を低く抑えてジッタを良好にすることができる。
【００２８】
Ｋ値、Δ３Ｔ値、ΔＰ値、ターゲットβ値を表１〜表６のように設定して記録を行うこの発明の光ディスク記録装置の実施の形態を以下説明する。図２１はこの発明が適用された光ディスク記録再生装置１のシステム構成を示すものである。入力装置２８ではオペレータの操作等により記録速度倍率が設定される。ディスクサーボ回路１６は、システムコントローラ１９からの指令により、スピンドルモータ１２を設定された記録速度倍率で線速度一定（１倍速時は１．２ｍ／ｓ〜１．４ｍ／ｓ、２倍速時は１倍速時の２倍、４倍速時は１倍速時の４倍、６倍速時は１倍速時の６倍、８倍速時は１倍速時の８倍）に制御する。速度一定制御は、オレンジブック規格の場合、プリグルーブのウォブル（Ｗｏｂｂｌｅ）が２２．０５kHz になるように規定されているので、光ヘッド１３の出力信号からウォブルを検出して（トラッキングエラー信号の残留分から検出できる。）、これが所定の周波数（１倍速時は２２．０５kHz 、２倍速時は４４．１kHz 、４倍速時は８８．２kHz 、６倍速時は１３２．３kHz 、８倍速時は１７６．４kHz 、……）で検出されるようにスピンドルモータ１２をＰＬＬ制御することで実現される。
【００２９】
フォーカスサーボおよびトラッキングサーボ回路１８は、システムコントローラ１９からの指令により、光ヘッド１３内の半導体レーザから出射されるレーザ光１１のフォーカスおよびトラッキングを制御する。トラッキング制御は光ディスク１０に形成されたプリグルーブを検出することにより行なわれる。フィードサーボ回路１７はシステムコントローラ１９からの指令により、フィードモータ２０を駆動して光ヘッド１３を光ディスク１０の径方向に移動させる。
【００３０】
光ディスク１０（通称ＣＤ−Ｒと呼ばれるＣＤ−ＷＯディスク）に記録すべき入力信号は、記録速度倍率に応じた速度でディジタル信号の場合は直接記録信号形成回路２２に入力され、オーディオ信号等のアナログ信号の場合はＡ／Ｄ変換器２４を経て記録信号形成回路２２に入力される。記録信号形成回路２２は、入力データにインタリーブをかけて、エラーチェックコードを付与し、またＴＯＣおよびサブコード生成回路２３で生成されるＴＯＣ情報およびサブコード情報を付与し、ＥＦＭ変調してＣＤ規格のフォーマットおよび記録速度倍率に応じた転送レートで一連のシリアルデータを形成し、記録信号として出力する。
【００３１】
この記録信号は、ドライブインターフェイス１５を介して記録信号補正回路２６で使用ディスク種類（色素材料別、メーカ別等）、線速度、記録速度倍率等に応じて選択された記録ストラテジーによる変調を受けてレーザ発生回路２５に入力される。レーザ発生回路２５は記録信号に応じて光ヘッド１３内の半導体レーザを駆動してレーザ光を光ディスク１０の記録面に照射し、ピットを形成して記録を行なう。この時のレーザパワーは記録速度倍率および必要に応じて線速度に応じた値に指令され、ＡＬＰＣ（Automatic Laser Power Control ）回路でこの指令されたパワーに高精度に制御される。これにより、光ディスク１０にはＣＤ規格のフォーマット、転送速度および線速度（１．２〜１．４ｍ／ｓ）でデータが記録される。なお、ターゲットβの値は記録速度倍率が高くなるほど低くなるが、レーザ光の記録パワー値自体は、記録速度倍率が高くなるほど高くなる。
【００３２】
以上のようにして記録した光ディスク１０に再生用レーザ光を照射して再生すると、読出データは信号再生処理回路３０で復調され、そのままディジタル信号として、またＤ／Ａ変換器３１でアナログ信号に変換されて出力される。
【００３３】
図２１のシステムコントローラ１９による記録制御の制御ブロックを図１に示す。記録速度倍率設定手段２８は図２１の入力装置２８に相当し、操作者の操作により記録速度倍率（×１，×２，×４，×６，×８，…）を設定する。ディスク種類および線速度判別手段３２は、装置にセットされている光ディスク１０のディスク種類および線速度を判別するものである。ディスク種類は、例えば光ディスク１０に予め記録されているディスクＩＤのうちディスク種類を示す情報を利用して判別することができる。あるいはディスク種類の選択スイッチ等を用意しておいて、ユーザが選択操作してディスク種類の情報を入力することもできる。また、線速度は例えばディスクのリードイン部のＡＴＩＰ信号に記録されている録音時間（６３分タイプ、７４分タイプその他それらの中間のタイプ）を読み取って、それから該当する線速度を判別（６３分タイプは１．４ｍ／ｓ、７４分タイプは１．２ｍ／ｓ）したり、スピンドルモータのエンコーダ出力から算出することができる。
【００３４】
記録ストラテジー記憶手段３４は、ディスク種類、線速度および記録速度倍率の組合せに応じて図２の記録パルスを表１〜表５に適合する設定で発生する記録ストラテジー（時間変化パターン、記録パワー等）を記憶している。また、記録速度倍率が高くなるほど低くなるターゲットβの最適値（表６に適合する値）も記憶している。記録ストラテジー選択手段３６は、入力されるディスク種類、線速度、記録速度倍率の情報に応じて該当する記録ストラテジーを記録ストラテジー記憶手段３４から読み出す。制御手段３８は読み出された記録ストラテジーに応じて記録信号補正回路２６を制御して記録信号のピット形成部分やブランク形成部分の長さに変調を加える。また、前述したＯＰＣ制御を実行して、記録速度倍率ごとに定められたターゲットβの最適値を実現する記録パワーを目標値として求めて記憶する。本番の記録時には、レーザ発生回路２５を制御して、レーザパワーを、指令された記録速度倍率について求められた目標値に制御する。また、ディスクサーボ回路１６を制御して、指令された記録速度倍率に相当する速度にスピンドルモータ１２を回転制御する。このようにして、光ディスク１０の記録が行われる。なお、上記実施の形態で記載した事項以外はオレンジブックパートII、Ｖｏｌ．３．０の規格に準拠する。
【図面の簡単な説明】
【図１】 この発明の実施の形態を示す制御ブロック図で、図２１のシステムコントローラによる記録制御の内容を示すものである。
【図２】 この発明の記録用レーザのレーザパワーの時間変化の一例を示す波形図である。
【図３】 シアニン系ディスクに１倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図４】 シアニン系ディスクに１倍速記録を行ったときの再生信号の３Ｔランドジッタ特性図である。
【図５】 シアニン系ディスクに２倍速記録を行ったときの再生信号の３Ｔランドジッタ特性図である。
【図６】 シアニン系ディスクに２倍速記録を行ったときの再生信号の３Ｔランドジッタ特性図である。
【図７】 シアニン系ディスクに６倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図８】 シアニン系ディスクに６倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図９】 フタロシアニン系ディスクに６倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図１０】 フタロシアニン系ディスクに６倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図１１】 フタロシアニン系ディスクに６倍速記録を行ったときの再生信号の１１Ｔピットデビエーション特性図である。
【図１２】 シアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔランドジッタ特性図である。
【図１３】 シアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図１４】 シアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図１５】 シアニン系ディスクに８倍速記録を行ったときの再生信号の１１Ｔピットデビエーション特性図である。
【図１６】 フタロシアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図１７】 フタロシアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔランドジッタ特性図である。
【図１８】 フタロシアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔピットジッタ特性図である。
【図１９】 フタロシアニン系ディスクに８倍速記録を行ったときの再生信号の３Ｔランドジッタ特性図である。
【図２０】 各記録速度倍率においてターゲットβの値を様々に変えて記録したときの再生信号の３Ｔランドジッタ特性である。
【図２１】 この発明を適用した光ディスク記録再生装置の実施の形態を示すシステム構成ブロック図である。
【符号の説明】
１０ 光ディスク
３８ 制御手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mark length recording type optical disk recording apparatus that records information by irradiating a recording surface of an optical disk with a laser beam to form a pit, and has a reproduction signal quality when recording at various recording speed magnifications. It is an improvement.
[0002]
[Prior art]
One standard for writable optical disks is the CD-WO (CD Write Once) standard (commonly known as the Orange Book standard). In the CD-WO standard, the laser beam irradiation time standard (recording strategy) in the pit format is (n−1) T + Δ3T for both 1 × speed recording and 2 × speed recording regardless of the type of dye on the disc.
However, nT: pit length to be formed, n = 3 to 11
Δ3T: A value added at the time of 3T long pit recording.
[0003]
Further, a target β is defined as a parameter related to the target value of the pit recording depth. The target β is the ratio of the sum and difference of the signal obtained by removing the DC component from the signal read from the optical disk (HF signal), where A1 is the peak value on the + side and A2 is the peak value on the − side.
β = (A1 + A2) / (A1-A2)
Is defined as When the recording speed magnification is the same, the value of the target β increases when the recording power is increased, and the value of the target β decreases when the recording power is decreased. When the recording speed magnification is different, in order to keep the value of the target β constant, it is necessary to increase the recording power as the recording speed magnification increases. In the Orange Book standard, the value of the target β is set to 0 to 8% regardless of the recording speed magnification. That is, the recording power value is determined for each recording speed magnification so that the value of the target β is 0 to 8% regardless of the recording speed magnification.
[0004]
In Japanese Patent Application No. 8-233596 relating to the application of the present applicant, the irradiation time of the laser beam is (n−K) T + α (nT) −β (mT).
Where K: constant α (nT): correction amount for each pit length, for example α (3T) ≧ α (4T) ≧ α (5T) ≧ …… ≧ α (8T) (α (3T)> α (8T ))
β (mT): Correction amount for each previous land length (a parameter unrelated to target β). At least β (3T) ≧ β (4T) ≧ β (5T) ≧ …… ≧ β (8T) (β (3T)> β (8T))
Thus, there is disclosed a recording strategy in which the K value is set to K = 0 to 0.5T in 6 × speed recording and K = 0 to 0.3T in 8 × speed recording, regardless of the type of dye on the disc.
[0005]
[Problems to be solved by the invention]
The recording state of the optical disk changes depending on the type of dye of the optical disk and the recording speed magnification, and the optimum reproduction signal quality cannot be obtained by the unified irradiation time control according to the Orange Book standard. Also, waveform distortion tends to appear in the playback signal as the recording speed magnification is increased. Therefore, when the value of the target β is fixed to 0 to 8% regardless of the recording speed magnification, playback is performed as the recording speed magnification increases. Waveform distortion is likely to appear in the signal waveform, and the quality of the reproduced signal has deteriorated. Further, according to the recording strategy of Japanese Patent Application No. 8-239396, the optimum reproduction signal quality cannot always be obtained depending on the disc type.
[0006]
An object of the present invention is to solve the problems in the prior art and provide an optical disk recording apparatus capable of obtaining an optimum reproduction signal quality according to the recording speed magnification.
[0007]
[Means for Solving the Problems]
The present invention is an optical disk recording apparatus capable of recording an optical disk with a variable recording speed magnification. The higher the recording speed magnification, the more the value of the reproduction signal target β that is a parameter related to the target value of the pit recording depth. Is provided with a control means for performing recording by controlling the recording power value of the laser beam such that the recording power becomes low. According to this, even if recording is performed at a higher recording speed magnification, waveform distortion is less likely to appear in the reproduced signal, and the quality of the reproduced signal is improved.
[0008]
As a method of recording by controlling the recording power value of the laser beam so that the value of the target β of the reproduction signal becomes lower as the recording speed magnification becomes higher, for example, an optimum value of the target β that becomes lower as the recording speed magnification becomes higher is used. Preliminarily obtained, the optimum value of target β for each recording speed magnification is stored in the memory as a target value, the recording speed magnification is set, and trial recording by OPC (Optimum Power Control) control defined by the Orange Book standard To automatically obtain the recording power value of the laser beam that achieves the target value of the target β determined for the recording speed magnification, and store it in the memory, during the actual recording at the recording speed magnification, Recording can be performed by controlling the actual recording power value using the recording power value as a target value.
[0009]
In this case, in the OPC control, for example, similarly to the conventional OPC control, the recording speed magnification is kept constant, and the recording power of the laser beam is changed in various ways, so that the PCA (Power Calibration) on the inner side of the lead-in area is changed. (Area) is recorded on a trial basis and reproduced after recording. The DC component contained in the reproduced HF signal is cut by a high-pass filter or the like, and the + and − side peak values of the signal are detected. The ratio of the sum and difference of peak values is calculated to determine the value of target β for each recording power, and each calculation result is compared with the target value of target β determined for the recording speed magnification. The recording power at which a close target β value is obtained is obtained, and the recording power is stored as the recording power target value at the recording speed magnification. The OPC control automatically executes this series of operations.
[0010]
As another method for performing recording by controlling the recording power value of the laser beam so that the value of the target β of the reproduction signal becomes lower as the recording speed magnification becomes higher, the optical disc recording apparatus performs OPC control by itself. Instead, for each disc type (by pigment type, by manufacturer, etc.), a recording power value that realizes the optimum value of the target β, which decreases as the recording speed magnification increases, is separately obtained in advance and stored in the memory and stored in the optical disc recording apparatus. When the optical disk recording apparatus performs recording, the disk type is detected from the disk ID recorded on the optical disk and the corresponding recording power value is read from the memory based on this and the setting information of the recording speed magnification. The actual recording can be performed by controlling the recording power value using the recording power value as a target value.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An example of the time change pattern of the laser power of the recording laser beam used in the present invention is shown in FIG. This is because the irradiation time of the laser beam is (n−K) T + Δ3T according to the pit length nT (n = 3, 4,..., 11) to be recorded.
K: Constant (Constant regardless of pit length at the same recording speed magnification)
Δ3T: A top that controls the value added at the time of 3T long pit recording and temporarily increases the beam power value of the laser beam for a predetermined period with respect to the reference recording power value at the beginning of irradiation of the laser beam forming each pit. The power addition pulse is controlled to be added to the pits of all pit lengths for the corresponding recording speed magnification (recording speed magnification where the ΔP value is other than 0% in Tables 1 to 5 described later). . That is, when n = 3, the laser power is increased to the top power Pt for a period of (3-K) T + Δ3T to form a 3T long pit, and when n = 4 to 11, the laser power (n−K) T A pit having a length of 4T to 11T is formed by increasing the period top power Pt. Between the pits, lands are formed by lowering the laser power to the bottom power Pb. At the beginning of the rise of the top power Pt, a top power addition pulse P1 having an addition level value ΔP and a width Δt is added to finely adjust the energy input amount (increase amount) to finely adjust the pit trailing edge position. If necessary, a bottom power off pulse P2 having a power value of 0 and an appropriate width is formed at the beginning of the fall of the top power Pt, and the energy input amount (decrease amount) is finely adjusted to adjust the trailing edge of the land. Fine-tune the position (front edge position of the next pit).
[0013]
FIG. 2 shows the characteristics of a reproduction signal when recording is performed at various recording speed magnifications by changing the K value, Δ3T value, and ΔP value on a cyanine disc and a phthalocyanine disc using the recording laser beam of FIG. 3 to FIG. Note that the pulse width Δt of the top power additional pulse P1 is constant at 1.25 T in any pit length at any recording speed magnification to which the top power additional pulse P1 is applied. Further, the bottom power off pulse P2 was not added (that is, the entire land formation section was made constant at the bottom power Pb). According to the Orange Book standard, 3T pit jitter and 3T land jitter are within 35 nsec within the range of 0 to 8% of target β, and 11T pit deviation (deviation: deviation from the normal length of pit or land) is the target β. Is required to be within ± 60 nsec within the range of 0 to 8%. Consider the K value, Δ3T value, and ΔP value that satisfy this requirement.
[0014]
(1) FIG. 3 shows 3T pit jitter characteristics of a reproduction signal when 1 × speed recording Δ3T = 0.3T is set, and the K value is changed to perform 1 × speed recording on a cyanine disc. According to this, the pit jitter is improved by making the K value larger than 1. Thus, when K = 1.25 was set and the Δ3T value was changed to perform 1 × speed recording on the same disk, the 3T land jitter characteristic of FIG. 4 was obtained. According to this, by setting Δ3T = 0.3T, the land jitter is improved and the power margin is widened.
[0015]
(2) FIG. 5 shows the 3T land jitter characteristics of the reproduction signal when the double speed recording Δ3T = 0.2T is set and the K value is changed and the double speed recording is performed on the cyanine disc. According to this, by making the K value smaller than 1, the land jitter is improved and the power margin is widened. Therefore, when K = 0.75 was set and the Δ3T value was changed and double speed recording was performed on the same disk, the 3T land jitter characteristic of FIG. 6 was obtained. According to this, by setting Δ3T = 0.2T, the land jitter is improved and the power margin is widened.
[0016]
(3) FIG. 7 shows the 3T pit jitter characteristics of the reproduction signal when 6 × speed recording Δ3T = 0.1T is set and the K value is changed to perform 6 × speed recording on a cyanine disc. According to this, by setting K = 0.2, the pit jitter is improved and the power margin is widened. Therefore, when 6 = speed recording was performed on the same disk by setting K = 0.2 and changing the Δ3T value, the 3T pit jitter characteristic of FIG. 8 was obtained. According to this, by setting Δ3T = 0.1T, the pit jitter is improved and the power margin is widened.
[0017]
FIG. 9 shows the 3T pit jitter characteristics of the reproduced signal when Δ3T = 0.15T is set and the K value is changed and 6 × speed recording is performed on the phthalocyanine disc. According to this, by setting K = 0.2, the pit jitter is improved and the power margin is widened. Therefore, when K = 0.2 was set and the ΔP value was changed and 6 × speed recording was performed on the same disk, the 3T pit jitter characteristic of FIG. 10 and the 11 pit deviation characteristic of FIG. 11 were obtained. According to this, although ΔP = 15% (the numerical value (%) of ΔP is a ratio to Pt−Pb in FIG. 2) and ΔP = 20%, the power margin is similar (FIG. 10). Since ΔP = 15% is better for 11T pit deviation (FIG. 11), it can be said that ΔP = 15% is preferable.
[0018]
(4) 3T land jitter characteristics and 3T pit jitter characteristics of the reproduced signal when 8 × speed recording is set to Δ3T = 0.2T and the K value is changed and 8 × speed recording is performed on a cyanine disc is shown in FIGS. Each is shown. According to this, when K = 0.00, the rise of the land jitter is faster than K = −0.12 and the power margin is narrow (FIG. 12), but for pit jitter, the power margin is K = 0.00. Therefore, it can be said that K = 0.00 is preferable. Therefore, when K = 0.00 was set and the ΔP value was changed and 8 × speed recording was performed on the same disk, the 3T pit jitter characteristic of FIG. 14 and the 11T pit deviation characteristic of FIG. 15 were obtained. According to this, when ΔP = 20% and ΔP = 30%, the pit jitter should be ΔP = 30% (FIG. 14), but ΔP = 30% does not satisfy the standard because 11T pit deviation does not satisfy the standard. 20% is appropriate.
[0019]
FIGS. 16 and 17 show the 3T pit jitter characteristic and 3T land jitter characteristic of the reproduction signal when Δ3T = 0.2T is set and the K value is changed and 8 × speed recording is performed on the phthalocyanine disc. According to this, when K = 0.12, both pit jitter and land jitter are good. Therefore, when K = 0.12 was set and ΔP value was changed and 8 × speed recording was performed on the same disk, the 3T pit jitter characteristic of FIG. 18 and the 3T land jitter characteristic of FIG. 19 were obtained. According to this, when ΔP = 20%, the power margin becomes wide.
[0020]
Taking into consideration the above results and other characteristics (error rate characteristics (C1 error characteristics, etc.), etc.), the optimum range of K value, Δ3T value, ΔP value for each recording speed magnification for cyanine discs and phthalocyanine discs As a result, the results shown in Tables 1 to 5 were obtained. The ΔP value is for a pulse width Δt of 1.25T. When the pulse width Δt is not 1.25T, the ΔP value is set so as to supply laser light energy equivalent to the case of 1.25T (if the Δt value is increased, the ΔP value is decreased and the Δt value is decreased). The ΔP value is increased.
[0021]
[Table 1]

[0022]
[Table 2]

[0023]
[Table 3]

[0024]
[Table 4]

[0025]
[Table 5]

According to Tables 1 to 5, the K value can be approximated by the following equation when the recording speed magnification is x.
[0026]
Cyanine series: K = −0.16x + 1.2
Phthalocyanine series: K = −0.15x + 1.15
Further, FIG. 20 shows 3T land jitter characteristics of a reproduction signal when the value of the target β is changed at various recording speed magnifications and recorded on a cyanine disc. According to this, it can be seen that the land jitter becomes better when the value of the target β is lowered as the recording speed magnification becomes higher. The optimum range of the target β for each recording speed magnification is shown in Table 6 (can be commonly applied to cyanine discs and phthalocyanine discs).
[0027]
[Table 6]

Since the target β is related to the recording depth, and the recording depth changes with the laser power at the time of recording, the target β can be controlled by the laser power (top power) Pt at the time of recording. That is, when the laser power Pt is increased, the value of the target β increases, and when the laser power Pt is decreased, the value of the target β decreases. Accordingly, the value of the laser power Pt at which the optimum target β value (Table 6) can be obtained is obtained in advance, and recording is performed by controlling the laser power Pt in accordance with the recording speed magnification at the time of actual recording. Therefore, even when recording is performed at any recording speed magnification, the waveform distortion of the reproduction signal can be suppressed to be low and the jitter can be improved.
[0028]
Embodiments of an optical disk recording apparatus according to the present invention for recording with the K value, Δ3T value, ΔP value, and target β value set as shown in Tables 1 to 6 will be described below. FIG. 21 shows a system configuration of the optical disc recording / reproducing apparatus 1 to which the present invention is applied. In the input device 28, the recording speed magnification is set by an operator's operation or the like. In response to a command from the system controller 19, the disk servo circuit 16 has a constant linear velocity at a set recording speed magnification of the spindle motor 12 (1.2m / s to 1.4m / s at 1x speed, 1 at 2x speed). 2 times at double speed, 4 times at 4 times speed, 4 times at 1 time speed, 6 times at 6 times speed at 1 time, and 8 times at 1 time speed at 8 times speed. In the case of the Orange Book standard, the constant speed control is defined so that the pre-groove wobble is 22.05 kHz. Therefore, the wobble is detected from the output signal of the optical head 13 (the tracking error signal remains). ), This is the predetermined frequency (22.05kHz at 1x speed, 44.1kHz at 2x speed, 88.2kHz at 4x speed, 132.3kHz at 6x speed, 176.4kHz at 8x speed) ,...)), And is realized by PLL control of the spindle motor 12.
[0029]
The focus servo and tracking servo circuit 18 controls the focus and tracking of the laser beam 11 emitted from the semiconductor laser in the optical head 13 according to a command from the system controller 19. Tracking control is performed by detecting pregrooves formed on the optical disk 10. The feed servo circuit 17 drives the feed motor 20 according to a command from the system controller 19 to move the optical head 13 in the radial direction of the optical disk 10.
[0030]
An input signal to be recorded on the optical disc 10 (commonly called a CD-R disc called CD-R) is directly input to the recording signal forming circuit 22 in the case of a digital signal at a speed corresponding to the recording speed magnification, and is an analog such as an audio signal. In the case of a signal, the signal is input to the recording signal forming circuit 22 via the A / D converter 24. The recording signal forming circuit 22 interleaves the input data, adds an error check code, adds TOC information and subcode information generated by the TOC and subcode generation circuit 23, performs EFM modulation, and performs CD standards. A series of serial data is formed at a transfer rate corresponding to the format and the recording speed magnification, and output as a recording signal.
[0031]
This recording signal is modulated by the recording signal correction circuit 26 via the drive interface 15 according to the recording strategy selected according to the type of disk used (by pigment material, by manufacturer, etc.), linear velocity, recording velocity magnification, etc. Input to the laser generation circuit 25. The laser generating circuit 25 drives the semiconductor laser in the optical head 13 in accordance with the recording signal, irradiates the recording surface of the optical disk 10 with the laser beam, forms pits, and performs recording. The laser power at this time is commanded to a value corresponding to the recording speed magnification and the linear velocity as required, and is controlled to this commanded power with high accuracy by an ALPC (Automatic Laser Power Control) circuit. As a result, data is recorded on the optical disc 10 at the CD standard format, transfer rate, and linear velocity (1.2 to 1.4 m / s). The value of the target β decreases as the recording speed magnification increases, but the recording power value of the laser light itself increases as the recording speed magnification increases.
[0032]
When reproduction is performed by irradiating the optical disk 10 recorded as described above with reproduction laser light, the read data is demodulated by the signal reproduction processing circuit 30 and converted as it is into a digital signal or converted into an analog signal by the D / A converter 31. Is output.
[0033]
FIG. 1 shows a control block for recording control by the system controller 19 of FIG. The recording speed magnification setting means 28 corresponds to the input device 28 in FIG. 21, and sets the recording speed magnification (× 1, × 2, × 4, × 6, × 8,...) By the operation of the operator. The disc type and linear velocity discriminating means 32 discriminates the disc type and linear velocity of the optical disc 10 set in the apparatus. The disc type can be determined using information indicating the disc type among disc IDs recorded in advance on the optical disc 10, for example. Alternatively, a disc type selection switch or the like is prepared, and the user can select and input disc type information. For example, the linear velocity is read from the recording time (63-minute type, 74-minute type, or other intermediate type) recorded in the ATIP signal in the lead-in portion of the disk, and the corresponding linear velocity is discriminated (63 minutes). (The type is 1.4 m / s, the 74 minute type is 1.2 m / s), and can be calculated from the encoder output of the spindle motor.
[0034]
The recording strategy storage means 34 generates a recording pulse (time change pattern, recording power, etc.) of the recording pulses shown in FIG. 2 according to the combination of the disc type, linear velocity, and recording velocity magnification with the settings suitable for Tables 1 to 5. Is remembered. In addition, an optimum value of the target β (a value that conforms to Table 6), which decreases as the recording speed magnification increases, is also stored. The recording strategy selection means 36 reads the corresponding recording strategy from the recording strategy storage means 34 in accordance with the input disc type, linear velocity, and recording speed magnification information. The control means 38 controls the recording signal correction circuit 26 in accordance with the read recording strategy, and modulates the length of the pit formation portion or blank formation portion of the recording signal. Further, the above-described OPC control is executed, and the recording power for realizing the optimum value of the target β determined for each recording speed magnification is obtained and stored as a target value. During the actual recording, the laser generation circuit 25 is controlled to control the laser power to the target value obtained for the commanded recording speed magnification. Further, the disk servo circuit 16 is controlled to rotate the spindle motor 12 at a speed corresponding to the commanded recording speed magnification. In this way, recording on the optical disk 10 is performed. Other than the matters described in the above embodiment, Orange Book Part II, Vol. Conforms to the 3.0 standard.
[Brief description of the drawings]
FIG. 1 is a control block diagram showing an embodiment of the present invention, and shows the contents of recording control by a system controller of FIG.
FIG. 2 is a waveform diagram showing an example of a temporal change in laser power of the recording laser of the present invention.
FIG. 3 is a 3T pit jitter characteristic diagram of a reproduction signal when 1 × speed recording is performed on a cyanine disc.
FIG. 4 is a 3T land jitter characteristic diagram of a reproduction signal when 1 × speed recording is performed on a cyanine disc.
FIG. 5 is a 3T land jitter characteristic diagram of a reproduction signal when double speed recording is performed on a cyanine disc.
FIG. 6 is a 3T land jitter characteristic diagram of a reproduction signal when double speed recording is performed on a cyanine disc.
FIG. 7 is a 3T pit jitter characteristic diagram of a reproduction signal when 6 × speed recording is performed on a cyanine disc.
FIG. 8 is a 3T pit jitter characteristic diagram of a reproduction signal when 6 × speed recording is performed on a cyanine disc.
FIG. 9 is a 3T pit jitter characteristic diagram of a reproduction signal when 6 × speed recording is performed on a phthalocyanine disc.
FIG. 10 is a 3T pit jitter characteristic diagram of a reproduction signal when 6 × speed recording is performed on a phthalocyanine disc.
FIG. 11 is an 11T pit deviation characteristic diagram of a reproduction signal when 6 × speed recording is performed on a phthalocyanine disc.
FIG. 12 is a 3T land jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a cyanine disc.
FIG. 13 is a 3T pit jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a cyanine disc.
FIG. 14 is a 3T pit jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a cyanine disc.
FIG. 15 is an 11T pit deviation characteristic diagram of a reproduction signal when 8 × speed recording is performed on a cyanine disc.
FIG. 16 is a 3T pit jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a phthalocyanine disc.
FIG. 17 is a 3T land jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a phthalocyanine disc.
FIG. 18 is a 3T pit jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a phthalocyanine disc.
FIG. 19 is a 3T land jitter characteristic diagram of a reproduction signal when 8 × speed recording is performed on a phthalocyanine disc.
FIG. 20 is a 3T land jitter characteristic of a reproduction signal when recording is performed by changing the value of the target β at various recording speed magnifications.
FIG. 21 is a system configuration block diagram showing an embodiment of an optical disc recording / reproducing apparatus to which the present invention is applied.
[Explanation of symbols]
10 Optical disk 38 control means

Claims (2)

An optical disk recording apparatus capable of recording an optical disk with a variable recording speed magnification,
The peak value on the + side of the signal obtained by removing the DC component from the HF signal read from the optical disk is A1, and the peak value on the − side is A2.
β = (A1 + A2) / (A1-A2)
Is defined as a target β that is a parameter related to the target value of the pit recording depth,
As the recording speed magnification increases, the recording power of the laser beam is increased,
Optimal range of target beta as recording speed increase ratio becomes higher in accordance with the characteristics of the optical disc will remained on the lower of the value of the target beta, as the recording speed increase ratio is high, the value of target beta Playback signal An optical disk recording apparatus comprising control means for performing recording by controlling a recording power value of a laser beam so as to be low. An optical disk recording apparatus capable of recording an optical disk with a variable recording speed magnification,
Β is obtained by setting the peak value on the + side of the signal obtained by removing the DC component from the HF signal read from the optical disc to A1, the peak value on the − side as A2, and
β = (A1 + A2) / (A1-A2)
In the relationship between jitter and β, the range of β where the jitter changes well is taken as the optimal range of β,
The higher the recording speed magnification, the higher the recording power of the laser light so that the value of β of the reproduction signal fits the optimum range of β,
Optimal range of beta as the recording speed increase ratio becomes higher in accordance with the going remained in the lower of the value of beta, as the recording speed increase ratio is high, playback signal laser beam so that the value is lower in beta of An optical disk recording apparatus comprising control means for controlling the recording power value of the recording medium.

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