JP3981207B2 - Optical disk device - Google Patents

Description

【表２】

なお、上述したように、本実施の形態では、ゾーン０及びゾーン１６で試し書きを行うとしたが、これに限らず、１つのゾーン例えばゾーン０のみで試し書きを行い、決定した記録パワーに基づき直線近似することにより他のゾーンの記録パワーを決定するようにしても良くこの場合は記録パワーの設定時間が短縮でき、また、ゾーン０及びゾーン１６の２つのゾーン以外の１つまたは複数のゾーンに対して試し書きを行ってもよくこの場合各ゾーンの記録パワーを精度良く決定することができる。
【００２８】
次にこのように構成された本実施の形態の作用について説明する。すなわち、本実施の形態の光磁気ディスク装置１での試し書きによる記録パワーの決定方法について説明する。
【００２９】
まず、光磁気ディスク２が光磁気ディスク装置１にローディングされると、図４に示すように、ドライブコントローラ１１は、ステップＳ１で試し書きを行うテストトラックヘ光ピックアップを移動する。この場合のテストトラックはゾーン０のテストトラックである（図２参照）。
【００３０】
次に、ステップＳ２でテストライトパワーＰｔに予め決定された初期値を設定し、ステップＳ３で記憶回路１４に格納されている試し書き禁止セクタを除いた試し書きを行うテストトラックの所定のセクタにライトする。
【００３１】
ここで、ライトするデータパターンは後の動作で振幅測定を行うため、単一パターンの繰り返しが望ましい。
【００３２】
そして、ドライブコントローラ１１はステップＳ４において、ステップＳ３でライトしたデータの振幅を振幅検出回路１２からの出力をモニタすることにより測定し、ステップＳ５においてステップＳ４でモニタした振幅値が予め規定しておいた規定下限値よりも小さいかどうか判断し、小さければステップＳ６でテストライトパワーＰｔを増加させ、さらにステップＳ７で増加させたテストライトパワーＰｔが実際の記録パワーの上限値Ｐｍａｘに達したかどうか判断し、上限値Ｐｍａｘに達した場合にはエラー処理を行い処理を終了し、上限値Ｐｍａｘに達していない場合にはステップＳ３に戻り再度ライトを行う。
【００３３】
また、ステップＳ５でモニタした振幅値が予め規定しておいた規定下限値以上と判断した場合には、ステップＳ８において、モニタした振幅値が予め規定しておいた規定上限値以内かどうか判断し、規定上限値を越えていればステップＳ９でテストライトパワーＰｔを減少させ、さらにステップＳ１０で減少させたテストライトパワーＰｔが実際の記録パワーの下限値Ｐｍｉｎに達したかどうか判断し、下限値Ｐｍｉｎに達した場合にはエラー処理を行い処理を終了し、下限値Ｐｍｉｎに達していない場合にはステップＳ３に戻り再度ライトを行う。この動作を繰り返して、ライトしたデータの振幅値が規定された範囲内になるテストライトパワーＰｔを決定する。
【００３４】
なお、振幅の目標値（規定範囲の中心）が小さすぎるとノイズによる振幅測定の誤差が大きくなり好ましくない。逆に振幅の目標値が大きすぎるとライトしたデータの振幅が飽和してくるため、ライトパワー変動に対する振幅の変動が小さくなりテストライトパワーＰｔの誤差が大きくなるため好ましくない。
【００３５】
そして、ステップＳ８でモニタした振幅値が予め規定しておいた規定上限値以内と判断した場合には、図５に示すように、ステップＳ１１で決定したテストライトパワーでテストトラックの別のセクタでライトを行い、ステップＳ１２でライトしたデータの振幅をモニタする。そして、ステップＳ１３でこの別にセクタでモニタした振幅値が規定上限値及び規定下限値で定められる規定値の範囲内であるかどうか判断し、範囲外ならばステップＳ１４で更なる別のセクタに移動し、図４のステップＳ２に戻り処理を繰り返す。
【００３６】
そして、ステップＳ１３において振幅値が規定値の範囲内ならば、記録パワー演算回路１３によりステップＳ１５で上記の処理で決定したテストライトパワーＰｔに対して係数倍した値を実際にデータをライトする際の記録パワーとする。ここで、図６に示すようなパルス列による多値記録の場合には、それぞれのピークパワー（Ｐ１，Ｐ２，Ｐ３，…，Ｐｎ）について決定したテストライトパワーＰｔを係数倍（α１，α２，α３，…，αｎ）することで求める。なお、この係数α１，α２，α３，…，αｎは、予め記録パワー演算回路１３に格納されている。
【００３７】
続いて、図５に戻り、ステップＳ１６において、ステップＳ１５で決めた記録パワーで所定のセクタにライトを行い、ステップＳ１７でライトが正常かどうか判断し（ベリファイ時にエラーとならない）、できていない場合にはエラー処理を行い処理を終了し、できている場合にはステップＳ１８でテストトラックがゾーン１６かどうか判断し、ゾーン１６ならばゾーン０とゾーン１６での記録パワーに基づいて直線近似を行い他のゾーンの記録パワーを決定して処理を終了する。
【００３８】
上記の説明ではテストトラックはゾーン０であるので、ステップＳ１８から図４のステップＳ１に戻り、ステップＳ１でゾーン１６のテストトラックに移動し、上記処理を繰り返しゾーン１６における記録パワーを決定し、ステップＳ１８でゾーン０とゾーン１６での記録パワーに基づいて直線近似を行い他のゾーンの記録パワーを決定して処理を終了する。なお、ゾーン１６のときのステップＳ２におけるテストライトパワーＰｔの初期値は、ゾーン０で決定したテストライトパワーＰｔに基づき算出され設定される。
【００３９】
上記係数αｉ（ｉ＝１〜ｎ）は温度やディスクフォーマット、試し書きを行うバンド，ディスクの種類（ダイレクトオーバライト（ＤＯＷ）のディスクか、ダイレクトオーバライトではない（ＮＯＮ一ＤＯＷ）ディスク等）によって適正値を設定することが望ましい。
【００４０】
ここで、係数αｉ（ｉ＝１〜ｎ）の設定の第１の例を、３値パワー（Ｐ１，Ｐ，Ｐ３）によるパルス列記録により信号の記録を行う場合を例に説明する。
【００４１】
一般に、光ディスク記録の信号判定には、エラーレートによる判定が用いられている。上記３値をそれぞれ可変にした際、エラーレートはそれぞれ変動するが、光ディスクドライブの信号読み取りにおいてはエラー訂正（以下、ＥＣＣと記載する）が行われ、あるレベルまでのエラーレート特性を持つ記録信号であれば正常に信号読み取りが可能になる。Ｐ１、Ｐ２、Ｐ３の比率を一定にして、Ｐ３についてパワーを可変にした際のエラーレート特性の変動を図７のグラフに記裁する。このとき、黒線にて記載したエラーレートを、ＥＣＣによる補正可能なエラーレート限界とすると、図７での良好な記録領域は、
Ｐｍｉｎ≦Ｐ３≦Ｐｍａｘ
で規定される（以下、この記録領域Ｐｍａｘ−Ｐｍｉｎをパワーマージンと記載する）。
【００４２】
Ｐ１：Ｐ２：Ｐ３の比をそれぞれ変更して、Ｐ３を可変にしたときのエラーレート測定を行うと、各々の比に対するパワーマージンを測定することができる。これを用いて、ｘ軸にＰ１とＰ３の比、ｙ軸にＰ２とＰ３の比、ｚ軸にパワーマージン値をプロットしたグラフを作成すると、図８に示すようなｚ軸方向に対してパワーマージンの等高線を描いたグラフを作成できる。このグラフのうち、山頂部位、最もパワーマージンが確保できる領域をＰ３に対する各々Ｐ１、Ｐ２のパワー比率とする。
【００４３】
すなわち
Ｐ１＝ａ１×Ｐ３，Ｐ２＝ａ２×Ｐ３ （ａ１，ａ２は定数）
さらに、上記パワーマージン山頂部でのＰ２に対するエラーレート特性グラフのうち、書き始めパワーＰｍｉｎに、ドライブで記録を行う際に予測されうるパワー変動、例えばテストライトパワーＰｔの測定での検出誤差、ドライブ電気系での誤差をマージンとして見積もり、Ｐ３の目標値とする。
【００４４】
つまり、
Ｐ３＝Ｐｍｉｎ／ｂ （ｂは光ディスクドライブ記録時に考えられる誤差）
ここで、ドライブで考慮される最大誤差を見積もることで、ｂを定数として規定できる。また、テストライトパワーＰｔに対してのＰｍｉｎの比率をｃとすると、
Ｐｍｉｎ＝ｃ×Ｐｔ
Ｐｍｉｎ、Ｐｔは共に媒体の記録感度により変動する値なので、その比は一意の定数ｃで表される。
【００４５】
従って、テストライトパワーＰｔを求めることで、
Ｐ１＝ａ１×ｃ／ｂ×Ｐｔ＝α１×Ｐｔ
Ｐ２＝ａ２×ｃ／ｂ×Ｐｔ＝α２×Ｐｔ
Ｐ３＝ｃ／ｂ×Ｐｔ＝α３×Ｐｔ
となり、テストライトパワーＰｔに対して、各最適な３値パワーＰ１，Ｐ２，Ｐ３は一意の定数比率、α１，α２，α３にて規定される。
【００４６】
つまり、このα１，α２，α３を記録パワー演算回路１３に格納すればよい。
【００４７】
次に係数αｉ（ｉ＝１〜ｎ）の設定の第２の例を説明する。ＩＳＯ／ＩＥＣ１５０４１で規定される５４０／６４０ＭＢ容量光磁気ディスクの中には、光変調ダイレクトオーバーライト記録（以下、ＬＩＭ一ＤＯＷと記載する）ディスクも規定されている。ＬＩＭ一Ｄ０Ｗディスクにおいては、上記３値のパルス列記録のうち、Ｐ１のパワーにて消去動作、Ｐ２及びＰ３のパワーにて記録を行うことにて消去動作を行うことなく、上書き記録を可能としている。
【００４８】
このときパワーＰ１には、記録信号のジッタ特性の最適化の他に、消去動作も同時に行うため、消去に十分なマージンを持って設定されることが望まれる。ＬＩＭ−ＤＯＷディスクの消去及び記録特性を図９に記載する。Ｐ１をテストライトパワーＰｔから一定比α１で設定する場合、テストライトパワーＰｔのディスク、ドライブの生産ばらつきによる変動分を±ｄとすると、
±ｄ１＝±ｄ×α１
で、消去動作、及び十分な記録パワーマージンがあることを確認する必要がある。
【００４９】
そこで、Ｐ１及びＰ１±ｄ１にてＰ１値を固定し、さらにＰ２：Ｐ３の比を変えてＰ３についてパワーマージン測定を行った結果を図１０ないし図１２に記載する。図１０ないし図１２でＰ２：Ｐ３の比で最もパワーマージンが確保でき、かつ、Ｐ１±ｄ１でパワーマージンの取れるＰ１を選択し、前記Ｐ１とＰｔとの比を
Ｐ１＝α１×Ｐｔ
とする。さらに、前記Ｐ２：Ｐ３の最適比より、
Ｐ２＝ａ２×Ｐ３
とし、さらに、Ｐ３の書き始めに対してドライブで考慮される最大誤差ｂを見積もり、
Ｐ３＝Ｐｍｉｎ／ｂ
さらに、Ｐ３及びＰｔの比は感度に依存するので、
Ｐｍｉｎ＝ｃ×Ｐｔ
となる。
【００５０】
従って、ＬＩＭ一ＤＯＷディスクにおいても、通常のディスクと同様に、
Ｐ１＝α１×Ｐｔ
Ｐ２＝ａ２×ｃ／ｂ×Ｐｔ＝α２×Ｐｔ
Ｐ３＝ｃ／ｂ×Ｐｔ＝α３×Ｐｔ
となり、テストライトパワーＰｔに対して、各最適な３値パワーＰ１，Ｐ２，Ｐ３は一意の定数比率、α１，α２，α３にて規定される。
【００５１】
つまり、ＬＩＭ一ＤＯＷディスクの場合も、このα１，α２，α３を記録パワー演算回路１３に格納すればよい。
【００５２】
以上のように、本実施の形態では、ライトした情報の再生信号の振幅を測定し、その測定値に基づきテストライトパワーＰｔを決定し、決定したテストライトパワーＰｔに所定の係数を乗算することで記録パワーを設定しており、振幅測定が光磁気ディスクの感度ムラや回転偏差等の影響を受けることがないので、精度良く各ゾーンの記録パワーを設定することができる。
【００５３】
なお、テストライトパワーＰｔの決定を、図３におけるステップＳ１〜Ｓ１０で行うとしたが、これに限らず、図１３に示すようにしても良い。
【００５４】
すなわち、図１３に示すように、ステップＳ１〜Ｓ４の処理を終えた後、ステップＳ３１にて、ステップＳ４でモニタした振幅値が予め規定しておいた第１目標下限値よりも小さいかどうか判断し、小さければステップＳ３２でテストライトパワーＰｔを例えば０．３ｍＷ増加させ、ステップＳ３に戻り再度ライトを行う。
【００５５】
また、ステップＳ３１にてステップＳ４でモニタした振幅値が予め規定しておいた第１目標下限値以上と判断した場合には、ステップＳ３３において、モニタした振幅値が予め規定しておいた第１目標上限値以内かどうか判断し、第１目標上限値を越えていればステップＳ３４でテストライトパワーＰｔを例えば０．３ｍＷ減少させ、ステップＳ３に戻り再度ライトを行う。
【００５６】
そして、ステップＳ３３においてモニタした振幅値が予め規定しておいた第１目標上限値以内と判断した場合には、ステップＳ３５で第１目標下限値から第１目標上限値の範囲のテストライトパワーＰｔで所定のセクタにライトする。ステップＳ３６にて、ステップＳ３５でライトしたデータの振幅を振幅検出回路１２からの出力をモニタすることにより測定し、ステップＳ３７でモニタした振幅値が予め規定しておいた第１目標下限値より大きい第２目標下限値よりも小さいかどうか判断し、小さければステップＳ３８でテストライトパワーＰｔを例えば０．１ｍＷ増加させ、ステップＳ３５に戻り再度ライトを行う。
【００５７】
また、ステップＳ３７にてステップＳ３６でモニタした振幅値が予め規定しておいた第２目標下限値以上と判断した場合には、ステップＳ３９において、モニタした振幅値が予め規定しておいた第１目標上限値より小さい第２目標上限値以内かどうか判断し、第２目標上限値を越えていればステップＳ４０でテストライトパワーＰｔを例えば０．１ｍＷ減少させ、ステップＳ３５に戻り再度ライトを行う。この動作を繰り返して、ライトしたデータの振幅値が規定された範囲内になるテストライトパワーＰｔを決定し、その後の処理を図４で説明したステップＳ１１に移行するようにしてもよい。
【００５８】
図１３のように処理することで、テストライトパワーＰｔの決定を振幅範囲レベルに応じて２段階で行っているため、高速にテストライトパワーＰｔを決定することができるという効果がある。
【００５９】
図１４及び図１５は本発明の第２の実施の形態に係わり、図１４は光磁気ディスク装置の構成を示す構成図、図１５は図１４の光磁気ディスク装置の作用を示すタイミング図である。
【００６０】
第２の実施の形態は、第１の実施の形態とほとんど同じであるので、異なる点のみ説明し、同一の構成には同じ符号をつけ説明は省略する。
【００６１】
図１４に示すように、本実施の形態の光磁気ディスク装置１ａでは、ドライブコントローラ１１からのセクタのセクタマーク（ＳＭ）をトリガとして所定値をカウントする第１のカウンタ２１及び第２のカウンタ２２と、ドライブコントローラ１１の制御により第１のカウンタ２１または第２のカウンタ２２のカウントアップ信号を振幅検出回路１２ａに出力するセレクタ２３とが設けられており、振幅検出回路１２ａはセレクタ２３からの第１のカウンタ２１または第２のカウンタ２２のカウントアップ信号が入力されると振幅検出を行うようになっている。
【００６２】
試し書きの際、ドライブコントローラ１１は、図１５に示すように、セクタマークを読み込むとトリガ信号を第１のカウンタ２１及び第２のカウンタ２２に出力する。第１のカウンタ２１は、第１の時間カウントしカウントアップ信号をセレクタ２３に出力し、第２のカウンタ２２は、第１の時間より長い第２の時間カウントしカウントアップ信号をセレクタ２３に出力する。ドライブコントローラ１１は、テストトラックの現在のセクタが記憶回路１４に記憶されている試し書き禁止セクタ（表１及び表２参照）の場合、第２のカウンタ２２のカウントアップ信号を選択するようにセレクタ２３を制御し、テストトラックの現在のセクタが記憶回路１４に記憶されている試し書き禁止セクタでない場合は、第１のカウンタ２１のカウントアップ信号を選択するようにセレクタ２３を制御する。これにより振幅検出回路１２ａは、セクタマークのあるＩＤ部から所定の距離離れたデータ記録部で振幅測定を行う。
【００６３】
その他の構成及び作用は第１の実施の形態と同じである。
【００６４】
このように本実施の形態では、第１の実施の形態と同様に、隣接するバッファトラックのＩＤ部の信号の影響を排除することができるという効果に加え、影響されるセクタでの振幅測定が可能であるので、効率的な測定が可能となる。
【００６５】
【発明の効果】
以上説明したように本発明の光ディスク装置によれば、レーザ制御手段により記録媒体上のテストエリアでパワーを順次可変してデータの書き込みを行い、振幅測定手段によりテストエリアのデータの再生信号の振幅測定を行い、振幅測定結果が予め決められた所定の範囲に入ったときのパワーであるテストパワーに基づいて記録パワー演算手段が記録パワーを演算し、制限手段がテストエリアでの振幅測定を制限するので、記録パワーを精度良く設定することができるという効果がある。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態に係る光磁気ディスク装置の構成を示す構成図
【図２】図１の光磁気ディスク装置に装着される光磁気ディスクの記録領域の構成を示す構成図
【図３】図２のテストトラック及びバッファトラックの構成を示す構成図
【図４】図１の光磁気ディスク装置の作用を説明する第１のフローチャート
【図５】図１の光磁気ディスク装置の作用を説明する第２のフローチャート
【図６】図５のフローチャートにより演算される記録パワーの一例を示す図
【図７】図５のフローチャートに用いられるテストライトパワーに乗算される係数の第１の例を説明する第１の説明図
【図８】図５のフローチャートに用いられるテストライトパワーに乗算される係数の第１の例を説明する第２の説明図
【図９】図５のフローチャートに用いられるテストライトパワーに乗算される係数の第２の例を説明する第１の説明図
【図１０】図５のフローチャートに用いられるテストライトパワーに乗算される係数の第２の例を説明する第２の説明図
【図１１】図５のフローチャートに用いられるテストライトパワーに乗算される係数の第２の例を説明する第３の説明図
【図１２】図５のフローチャートに用いられるテストライトパワーに乗算される係数の第２の例を説明する第４の説明図
【図１３】図４のフローチャートの変形例を示すフローチャート
【図１４】本発明の第２の実施の形態に係る光磁気ディスク装置の構成を示す構成図
【図１５】図１４の光磁気ディスク装置の作用を示すタイミング図
【図１６】従来のパルス列記録における記録パワーの波形を示す図
【符号の説明】
１…光磁気ディスク装置
２…光磁気ディスク
３…スピンドルモータ
４…光ピックアップ
６…ＬＤ
７…ＰＤ
８…ＬＤドライバ
９…へッドアンプ
１０…アナログ信号処理回路
１１…ドライブコントローラ
１２…振幅検出回路
１３…記録パワー演算回路
１４…記憶回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk apparatus, and more particularly to an optical disk apparatus characterized by a recording power setting portion.
[0002]
[Prior art]
Optical discs are attracting attention as a storage medium that is the core of multimedia that has been rapidly developing in recent years. For example, in the case of 3.5-inch magneto-optical discs, in addition to the conventional 128 MB and 230 MB, Recording media for high-density recording such as 640 MB are also being provided.
[0003]
By the way, for example, a 3.5-inch magneto-optical disk employs ZCAV recording (zone constant angular velocity recording) in which the medium track is divided into zones and the number of sectors in each zone is the same. The number of zones of the magneto-optical medium is limited to 1 zone for the conventional 128 MB medium and 10 zones for the 230 MB medium. However, in the case of high-density recording media such as 540 MB and 640 MB that have recently been put into practical use, With the improvement, the track pitch of the medium is narrowed, and the number of zones is also greatly increased.
[0004]
That is, the 640 MB medium has 11 zones and the number of zones is relatively small, but the 540 MB medium has 18 zones and the number of zones increased to nearly twice that of the prior art. Usually, in the case of a magneto-optical disk, there is a difference in the optimum recording power for each medium. Therefore, when the medium is loaded, light emission adjustment is performed so that trial writing is performed for each zone to adjust to the optimum recording power. .
[0005]
For example, as shown in Japanese Patent Laid-Open No. 9-293259, trial writing is performed in the inner zone and the outer zone, and the recording power in the zone between them is obtained by linear approximation to adjust the light emission. it can.
[0006]
Further, in conventional 128 MB and 230 MB media, recording is performed by pit position modulation (PPM), and the light emission power may be changed in two steps of erase power and recording power. Recording by radiation modulation (PWM) is adopted. In this PWM recording, it is necessary to change the light emission power in three stages of erase power, l-th write power, and second write power.
[0007]
As an example, recording on a 540/640 MB capacity magneto-optical disk defined by ISO / IEC15041 is given. In the 540/640 MB capacity magneto-optical recording, unlike the conventional magneto-optical recording, among the binary recordings of “0” and “1”, the recording value “1” is not the recording signal itself but the recording signal. The beginning and end of writing (hereinafter referred to as edges) are used. In edge recording, good jitter characteristics of the recording signal edge portion are required.
[0008]
For this reason, in the 540/640 MB magneto-optical disk, as shown in FIG. 16, the pre-heat power (hereinafter referred to as P1) for raising the medium temperature before signal recording and the front edge which is independent recording power at the front and rear edge portions, respectively. A partial recording power (hereinafter referred to as P2) and a trailing edge recording power (hereinafter referred to as P3) are provided, and P2 and P3 are arranged in a comb shape to avoid thermal interference between the front and rear edges with P1 as a base. Signal recording is performed by pulse train recording using so-called ternary power.
[0009]
As described above, in the case of a magneto-optical disk, since there is a difference in the optimum recording power for each temperature and medium, it is necessary to determine the recording power for each zone by trial writing.
[0010]
Therefore, for example, in Japanese Patent Laid-Open No. 62-285258, standard data is stored in advance in a ROM or the like, and the environmental temperature is first measured. The semiconductor laser is driven with a square wave having a duty ratio of 50% of the drive current value, and test writing is performed on the magneto-optical disk. Then, data recorded by trial writing is reproduced using a light receiving element, a secondary distortion detection circuit, and the like. At this time, the recording power for each zone is determined by changing the drive current value of the semiconductor laser and repeating the recording and reproduction so that the duty ratio of the reproduction signal is 50%, that is, the output of the secondary distortion detection circuit becomes zero. is doing.
[0011]
[Problems to be solved by the invention]
However, since the duty ratio of the reproduction signal in the above Japanese Patent Application Laid-Open No. 62-285258 fluctuates due to uneven sensitivity of the magneto-optical disk, rotation deviation or the like, the method using the duty ratio of the reproduction signal has high recording power. There is a problem that the decision cannot be made.
[0012]
The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical disc apparatus capable of setting recording power with high accuracy.
[0013]
[Means for Solving the Problems]
The optical disc apparatus of the present invention is on a recording medium. By irradiating a predetermined laser beam to a test area provided for each of a plurality of zones and configured by a plurality of sectors, In an optical disc apparatus for setting a recording power of laser light at the time of data recording, laser control means for arbitrarily controlling the power of the laser light, and information reproduction for reading out and reproducing recorded information on the recording medium recorded with the power Means, an amplitude measuring means for measuring the amplitude of the reproduction signal reproduced by the information reproducing means, and the test area on the recording medium by the laser control means. For a given sector in a given The power can be varied sequentially to Trial writing And A predetermined sector in the test area where the test writing has been performed Recording power calculating means for calculating the recording power based on the test power that is the power when the amplitude measurement result falls within a predetermined range determined in advance, Test area Test write prohibiting means for prohibiting the test write to the predetermined sector, With The trial writing prohibition means includes: Test area Storage means for storing, as a trial write-inhibited sector, a sector arranged at a position that inhibits amplitude measurement due to the influence of a signal of a predetermined sector in an adjacent zone during amplitude measurement With The test write to the test write inhibit sector stored in the test write inhibit sector storage means Is prohibited.
[0014]
In the optical disc apparatus of the present invention, the laser control means sequentially changes the power in the test area on the recording medium to write data, and the amplitude measuring means causes the amplitude of the reproduction signal of the data in the test area. Measurement is performed, the recording power calculation means calculates the recording power based on the test power that is the power when the amplitude measurement result falls within a predetermined range, and the limiting means is used in the test area. By limiting the amplitude measurement, it is possible to set the recording power with high accuracy.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
1 to 13 relate to the first embodiment of the present invention, FIG. 1 is a block diagram showing the configuration of the magneto-optical disk apparatus, and FIG. 2 is a diagram of the magneto-optical disk mounted on the magneto-optical disk apparatus of FIG. 3 is a block diagram showing the configuration of the recording area, FIG. 3 is a block diagram showing the configuration of the test track and the buffer track of FIG. 2, FIG. 4 is a first flowchart for explaining the operation of the magneto-optical disk apparatus of FIG. 1, and FIG. 2 is a second flowchart for explaining the operation of the magneto-optical disk apparatus of FIG. 1, FIG. 6 is a diagram showing an example of the recording power calculated by the flowchart of FIG. 5, and FIG. 7 is a test write power used in the flowchart of FIG. FIG. 8 is a second explanatory diagram illustrating a first example of a coefficient to be multiplied by the test write power used in the flowchart of FIG. 5; Figure FIG. 10 is a first explanatory diagram for explaining a second example of a coefficient to be multiplied by the test write power used in the flowchart of FIG. 5, and FIG. 10 is a diagram of a coefficient to be multiplied by the test write power used in the flowchart of FIG. 2 is a second explanatory diagram illustrating an example of FIG. 2, FIG. 11 is a third explanatory diagram illustrating a second example of a coefficient to be multiplied by the test write power used in the flowchart of FIG. 5, and FIG. FIG. 13 is a flowchart illustrating a modified example of the flowchart of FIG. 4, and FIG. 13 is a fourth explanatory diagram illustrating a second example of the coefficient multiplied by the test write power used in the flowchart.
[0017]
As shown in FIG. 1, in the magneto-optical disk apparatus 1 of the present embodiment, a magneto-optical disk 2 for magneto-optical recording of information is inserted, and the magneto-optical disk 2 is mounted on a spindle motor 3 and rotated by a loading mechanism (not shown). It comes to drive. An optical pickup 4 as an optical head is installed in the vicinity of the spindle motor 3 so as to be movable in the radial direction of the magneto-optical disk 2, and a recording / reproducing laser beam 5 is directed toward the magneto-optical disk 2. It comes to irradiate.
[0018]
The optical pickup 4 is provided with a laser diode (hereinafter referred to as LD) 6 that emits laser light 5 and a photodetector (hereinafter referred to as PD) 7 that receives reflected light from the magneto-optical disk 2. An optical system (not shown) that irradiates the laser beam 5 to a minute spot and irradiates the PD 7 with the reflected light from the magneto-optical disk 2 is installed.
[0019]
Further, an LD driver 8 is connected to the LD 6, and a driving current is supplied to the LD 6 by the LD driver 8. On the other hand, an analog signal processing circuit 10 is connected to the PD 7 via a head amplifier 9, and the output signal of the PD 7 is amplified by the head amplifier 9 and then binarized by the analog signal processing circuit 10. Yes.
[0020]
The binarized signal binarized by the analog signal processing circuit 10 is sent to the drive controller 11, subjected to demodulation and error correction processing by the drive controller 11, and read as data recorded on the magneto-optical disk 2. The read data is sent to, for example, a host computer (not shown) and various processes are performed.
[0021]
The amplitude detection circuit 12 detects the peak value of the output signal of the PD 7 amplified by the head amplifier 9. The peak value detected by the amplitude detection circuit 12 is read by the drive controller 11 and compared with a target value suitable for binarizing the detection signal, for example, and the gain of a variable gain amplifier (not shown) is adjusted, and an analog signal processing circuit 10, the binarization process can be performed stably.
[0022]
A recording power calculation circuit 13 and a storage circuit 14 are connected to the drive controller 11, and the recording power calculation circuit 13 is controlled by the drive controller 11 to perform a test for test writing on a test track of the magneto-optical disk 2 described later. The determination of the write power and the calculation of the actual recording power in each zone of the magneto-optical disk 2 based on this test write power are executed. On the other hand, the storage circuit 14 stores a sector that prohibits trial writing on the test track.
[0023]
The magneto-optical disk device 1 is provided with focusing means and tracking means (not shown).
[0024]
The magneto-optical disk 2 is a 540 MB medium, for example, and is provided with 18 zones from zone 0 to zone 17 as shown in FIG. 2 (see ISO / IEC15041). In addition to each user area for recording data, each zone is provided with a buffer track between adjacent zones, and a test track is provided between the outermost periphery of the user area and the buffer track. ing. In general, the test writing is performed on the test track to determine the recording power of the magneto-optical disk. In this embodiment, the test writing is first performed on the test track in the zone 0 which is the inner zone, and the recording power in the zone 0 is determined. Next, test writing is performed on the test track in the zone 16 which is the outer peripheral zone to determine the recording power in the zone 16, and linear approximation is performed using the recording power in the zone 0 and the recording power in the zone 16. Thus, the recording power of the other zone is determined.
[0025]
Here, as shown in FIG. 3, in the same zone (zone 0 or zone 16), sectors are provided radially and the sector ID portion is provided at the same position in the radial direction. 1 or zone 17), because the sector configuration is different and the radial position of the ID portion is different, in the test writing on the test track, depending on the sector, the signal of the ID portion of this adjacent zone may be birefringent at the time of reading. As a result, leakage occurs and spike noise or the like is generated. Therefore, there is a problem that the signal amplitude by the amplitude detection circuit 12 cannot be measured accurately.
[0026]
Therefore, in the present embodiment, the trial writing prohibited sector on the test track in zone 0 shown in Table 1 and the trial writing prohibited sector on the test track in zone 16 shown in Table 2 are stored in the storage circuit 14. .
[0027]
[Table 1]

[Table 2]

As described above, in the present embodiment, the trial writing is performed in the zone 0 and the zone 16, but the present invention is not limited to this. The trial writing is performed only in one zone, for example, the zone 0, and the determined recording power is obtained. The recording power of other zones may be determined by linear approximation based on this, in which case the recording power setting time can be shortened, and one or a plurality of zones other than the two zones of zone 0 and zone 16 can be reduced. Trial writing may be performed on the zone, and in this case, the recording power of each zone can be accurately determined.
[0028]
Next, the operation of the present embodiment configured as described above will be described. That is, a method for determining the recording power by trial writing in the magneto-optical disk apparatus 1 of the present embodiment will be described.
[0029]
First, when the magneto-optical disk 2 is loaded on the magneto-optical disk apparatus 1, as shown in FIG. 4, the drive controller 11 moves the optical pickup to the test track on which trial writing is performed in step S1. The test track in this case is a zone 0 test track (see FIG. 2).
[0030]
Next, in step S2, a predetermined initial value is set as the test write power Pt, and in step S3, a predetermined sector of the test track on which test writing is performed except for the test write prohibited sector stored in the storage circuit 14 is set. Write.
[0031]
Here, since the amplitude of the data pattern to be written is measured later, it is desirable to repeat a single pattern.
[0032]
In step S4, the drive controller 11 measures the amplitude of the data written in step S3 by monitoring the output from the amplitude detection circuit 12. In step S5, the amplitude value monitored in step S4 is defined in advance. Whether the test write power Pt is increased in step S6 and the test write power Pt increased in step S7 has reached the upper limit value Pmax of the actual recording power. If the upper limit value Pmax is reached, an error process is performed and the process is terminated. If the upper limit value Pmax has not been reached, the process returns to step S3 and writing is performed again.
[0033]
When it is determined that the amplitude value monitored in step S5 is equal to or greater than a predetermined lower limit value, it is determined in step S8 whether the monitored amplitude value is within a predetermined upper limit value. If the specified upper limit value is exceeded, the test write power Pt is decreased in step S9, and it is further determined whether or not the test write power Pt decreased in step S10 has reached the lower limit value Pmin of the actual recording power. If Pmin is reached, error processing is performed and the process is terminated. If the lower limit Pmin is not reached, the process returns to step S3 and writing is performed again. This operation is repeated to determine the test write power Pt in which the amplitude value of the written data falls within a specified range.
[0034]
If the target value of amplitude (the center of the specified range) is too small, an error in amplitude measurement due to noise increases, which is not preferable. On the other hand, if the target value of the amplitude is too large, the amplitude of the written data is saturated, so that the amplitude variation with respect to the write power variation becomes small and the error of the test write power Pt becomes large.
[0035]
If it is determined that the amplitude value monitored in step S8 is within a predetermined upper limit value defined in advance, as shown in FIG. 5, the test write power determined in step S11 is used in another sector of the test track. Writing is performed, and the amplitude of the data written in step S12 is monitored. Then, in step S13, it is determined whether or not the amplitude value monitored in this sector is within the range of the specified value determined by the specified upper limit value and the specified lower limit value. If it is out of the range, it is moved to another sector in step S14. Then, the process returns to step S2 of FIG.
[0036]
If the amplitude value is within the specified range in step S13, the recording power calculation circuit 13 actually writes data by multiplying the test write power Pt determined in the above processing in step S15 by a coefficient. Recording power. Here, in the case of multilevel recording using a pulse train as shown in FIG. 6, the test write power Pt determined for each peak power (P1, P2, P3,..., Pn) is multiplied by a coefficient (α1, α2, α3). , ..., αn). The coefficients α1, α2, α3,..., Αn are stored in the recording power calculation circuit 13 in advance.
[0037]
Subsequently, returning to FIG. 5, in step S16, writing to a predetermined sector is performed with the recording power determined in step S15. In step S17, it is determined whether or not the writing is normal (no error occurs during verification). In step S18, an error process is performed and the process ends. In step S18, it is determined whether or not the test track is zone 16, and if it is zone 16, linear approximation is performed based on the recording power in zone 0 and zone 16. The recording power of another zone is determined and the process is terminated.
[0038]
In the above description, since the test track is zone 0, the process returns from step S18 to step S1 in FIG. 4 and moves to the test track in zone 16 in step S1, and the above processing is repeated to determine the recording power in zone 16. In S18, linear approximation is performed based on the recording powers in the zone 0 and the zone 16, the recording powers in the other zones are determined, and the process ends. Note that the initial value of the test write power Pt in step S2 in the zone 16 is calculated and set based on the test write power Pt determined in the zone 0.
[0039]
The coefficient αi (i = 1 to n) depends on temperature, disk format, test writing band, disk type (direct overwrite (DOW) disk, non-direct overwrite (NON-DOW) disk, etc.) It is desirable to set an appropriate value.
[0040]
Here, a first example of setting the coefficient αi (i = 1 to n) will be described by taking as an example a case where signal recording is performed by pulse train recording with ternary power (P1, P, P3).
[0041]
Generally, determination based on an error rate is used for signal determination for optical disc recording. When each of the above three values is made variable, the error rate varies. However, error correction (hereinafter referred to as ECC) is performed in the optical disk drive signal reading, and the recording signal has error rate characteristics up to a certain level. If so, the signal can be read normally. The graph of FIG. 7 shows the fluctuation of the error rate characteristic when the ratio of P1, P2, and P3 is made constant and the power is varied for P3. At this time, if the error rate indicated by the black line is an error rate limit that can be corrected by ECC, a good recording area in FIG.
Pmin ≦ P3 ≦ Pmax
(Hereinafter, this recording area Pmax-Pmin is referred to as a power margin).
[0042]
If the ratio of P1: P2: P3 is changed and the error rate is measured when P3 is made variable, the power margin for each ratio can be measured. Using this, a graph in which the ratio of P1 and P3 is plotted on the x-axis, the ratio of P2 and P3 on the y-axis, and the power margin value on the z-axis is plotted. As shown in FIG. You can create a graph with margin contours. In this graph, the peak portion and the region where the most power margin can be secured are defined as the power ratio of P1 and P2 to P3, respectively.
[0043]
Ie
P1 = a1 * P3, P2 = a2 * P3 (a1 and a2 are constants)
Further, in the error rate characteristic graph with respect to P2 at the peak portion of the power margin, the power fluctuation that can be predicted when recording is performed by the drive to the writing start power Pmin, for example, the detection error in the measurement of the test write power Pt, the drive An error in the electrical system is estimated as a margin and set as a target value for P3.
[0044]
That means
P3 = Pmin / b (b is an error considered at the time of optical disk drive recording)
Here, b can be defined as a constant by estimating the maximum error considered in the drive. Further, if the ratio of Pmin to the test write power Pt is c,
Pmin = c × Pt
Since Pmin and Pt both vary depending on the recording sensitivity of the medium, the ratio is represented by a unique constant c.
[0045]
Therefore, by obtaining the test write power Pt,
P1 = a1 × c / b × Pt = α1 × Pt
P2 = a2 × c / b × Pt = α2 × Pt
P3 = c / b × Pt = α3 × Pt
Thus, the optimum ternary powers P1, P2, and P3 with respect to the test write power Pt are defined by unique constant ratios α1, α2, and α3.
[0046]
That is, α1, α2, and α3 may be stored in the recording power calculation circuit 13.
[0047]
Next, a second example of setting the coefficient αi (i = 1 to n) will be described. Among the 540/640 MB capacity magneto-optical disks defined by ISO / IEC15041, an optical modulation direct overwrite recording (hereinafter referred to as LIM-DOW) disk is also defined. In the LIM-D0W disk, overwriting can be performed without performing an erasing operation by performing the erasing operation with the power of P1 and the powers of P2 and P3 among the ternary pulse train recording. .
[0048]
At this time, the power P1 is desirably set with a sufficient margin for erasure because the erase operation is simultaneously performed in addition to the optimization of the jitter characteristic of the recording signal. FIG. 9 shows the erasing and recording characteristics of the LIM-DOW disc. When P1 is set at a constant ratio α1 from the test write power Pt, if the fluctuation due to production variation of the disk and drive of the test write power Pt is ± d,
± d1 = ± d × α1
Therefore, it is necessary to confirm that there is an erase operation and a sufficient recording power margin.
[0049]
Therefore, the result of performing power margin measurement on P3 by fixing the P1 value at P1 and P1 ± d1, and further changing the ratio of P2: P3. 10 to 12 It describes. In FIG. 10 to FIG. 12, P1 that can secure the power margin with the ratio of P2: P3 and that can take the power margin with P1 ± d1 is selected, and the ratio of P1 and Pt is set as follows.
P1 = α1 × Pt
And Furthermore, from the optimum ratio of P2: P3,
P2 = a2 × P3
And estimate the maximum error b considered by the drive for the start of writing P3,
P3 = Pmin / b
Furthermore, since the ratio of P3 and Pt depends on the sensitivity,
Pmin = c × Pt
It becomes.
[0050]
Therefore, in a LIM 1 DOW disk, as with a normal disk,
P1 = α1 × Pt
P2 = a2 × c / b × Pt = α2 × Pt
P3 = c / b × Pt = α3 × Pt
Thus, the optimum ternary powers P1, P2, and P3 with respect to the test write power Pt are defined by unique constant ratios α1, α2, and α3.
[0051]
That is, α1, α2, α3 may be stored in the recording power calculation circuit 13 even in the case of a LIM-DOW disc.
[0052]
As described above, in the present embodiment, the amplitude of the reproduction signal of the written information is measured, the test write power Pt is determined based on the measured value, and the determined test write power Pt is multiplied by a predetermined coefficient. Since the recording power is set in (1) and the amplitude measurement is not affected by the sensitivity unevenness or rotational deviation of the magneto-optical disk, the recording power of each zone can be set with high accuracy.
[0053]
Although the test write power Pt is determined in steps S1 to S10 in FIG. 3, the present invention is not limited to this, and may be as shown in FIG.
[0054]
That is, as shown in FIG. 13, after the processing of steps S1 to S4 is completed, it is determined in step S31 whether the amplitude value monitored in step S4 is smaller than a first target lower limit value defined in advance. If it is smaller, the test write power Pt is increased by, for example, 0.3 mW in step S32, and the process returns to step S3 to perform writing again.
[0055]
If it is determined in step S31 that the amplitude value monitored in step S4 is greater than or equal to the first target lower limit value defined in advance, in step S33, the monitored amplitude value is the first value defined in advance. It is determined whether it is within the target upper limit value, and if it exceeds the first target upper limit value, the test write power Pt is decreased by, for example, 0.3 mW in step S34, and the process returns to step S3 to perform writing again.
[0056]
If it is determined in step S33 that the monitored amplitude value is within the first target upper limit value defined in advance, the test write power Pt in the range from the first target lower limit value to the first target upper limit value is determined in step S35. To write to a predetermined sector. In step S36, the amplitude of the data written in step S35 is measured by monitoring the output from the amplitude detection circuit 12, and the amplitude value monitored in step S37 is larger than the first target lower limit value defined in advance. It is determined whether or not it is smaller than the second target lower limit value. If it is smaller, the test write power Pt is increased by, for example, 0.1 mW in step S38, and the process returns to step S35 to perform writing again.
[0057]
If it is determined in step S37 that the amplitude value monitored in step S36 is greater than or equal to the second target lower limit value previously defined, in step S39, the monitored amplitude value is the first defined in advance. It is determined whether or not the second target upper limit value is smaller than the target upper limit value. If the second target upper limit value is exceeded, the test write power Pt is decreased by, for example, 0.1 mW in step S40, and the process returns to step S35 to perform writing again. This operation may be repeated to determine the test write power Pt in which the amplitude value of the written data falls within a specified range, and the subsequent processing may be shifted to step S11 described with reference to FIG.
[0058]
By performing the processing as shown in FIG. 13, the test write power Pt is determined in two steps according to the amplitude range level, so that the test write power Pt can be determined at high speed.
[0059]
14 and 15 relate to the second embodiment of the present invention, FIG. 14 is a block diagram showing the configuration of the magneto-optical disk apparatus, and FIG. 15 is a timing diagram showing the operation of the magneto-optical disk apparatus of FIG. .
[0060]
Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components are denoted by the same reference numerals and description thereof will be omitted.
[0061]
As shown in FIG. 14, in the magneto-optical disk apparatus 1a of the present embodiment, a first counter 21 and a second counter 22 that count predetermined values using a sector mark (SM) of a sector from the drive controller 11 as a trigger. And a selector 23 that outputs a count-up signal of the first counter 21 or the second counter 22 to the amplitude detection circuit 12a under the control of the drive controller 11, and the amplitude detection circuit 12a is supplied from the selector 23. When the count-up signal of the first counter 21 or the second counter 22 is input, amplitude detection is performed.
[0062]
At the time of trial writing, the drive controller 11 outputs a trigger signal to the first counter 21 and the second counter 22 when the sector mark is read as shown in FIG. The first counter 21 counts a first time and outputs a count-up signal to the selector 23, and the second counter 22 counts a second time longer than the first time and outputs a count-up signal to the selector 23. To do. The drive controller 11 selects the count-up signal of the second counter 22 when the current sector of the test track is a trial write prohibited sector (see Tables 1 and 2) stored in the storage circuit 14. If the current sector of the test track is not the trial write prohibited sector stored in the storage circuit 14, the selector 23 is controlled to select the count-up signal of the first counter 21. As a result, the amplitude detection circuit 12a performs amplitude measurement at a data recording unit that is a predetermined distance away from the ID part having the sector mark.
[0063]
Other configurations and operations are the same as those in the first embodiment.
[0064]
As described above, in this embodiment, in the same way as in the first embodiment, in addition to the effect that the influence of the signal of the ID portion of the adjacent buffer track can be eliminated, the amplitude measurement in the affected sector is performed. Since this is possible, efficient measurement is possible.
[0065]
【The invention's effect】
As described above, according to the optical disk apparatus of the present invention, the laser control means sequentially changes the power in the test area on the recording medium to write the data, and the amplitude measuring means causes the amplitude of the reproduction signal of the test area data. The recording power calculation means calculates the recording power based on the test power, which is the power when the amplitude measurement result enters a predetermined range, and the limiting means limits the amplitude measurement in the test area. Therefore, there is an effect that the recording power can be set with high accuracy.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a magneto-optical disk device according to a first embodiment of the present invention.
2 is a configuration diagram showing a configuration of a recording area of a magneto-optical disk mounted on the magneto-optical disk apparatus of FIG. 1;
3 is a configuration diagram showing the configuration of a test track and a buffer track in FIG. 2;
FIG. 4 is a first flowchart for explaining the operation of the magneto-optical disk apparatus of FIG. 1;
FIG. 5 is a second flowchart for explaining the operation of the magneto-optical disk apparatus of FIG. 1;
6 is a diagram showing an example of recording power calculated by the flowchart of FIG.
FIG. 7 is a first explanatory diagram illustrating a first example of a coefficient multiplied by the test write power used in the flowchart of FIG. 5;
FIG. 8 is a second explanatory diagram illustrating a first example of coefficients multiplied by the test write power used in the flowchart of FIG.
FIG. 9 is a first explanatory diagram illustrating a second example of coefficients multiplied by the test write power used in the flowchart of FIG. 5;
10 is a second explanatory diagram illustrating a second example of a coefficient multiplied by the test write power used in the flowchart of FIG.
FIG. 11 is a third explanatory diagram illustrating a second example of coefficients multiplied by the test write power used in the flowchart of FIG.
12 is a fourth explanatory diagram illustrating a second example of coefficients multiplied by the test write power used in the flowchart of FIG.
FIG. 13 is a flowchart showing a modification of the flowchart of FIG.
FIG. 14 is a configuration diagram showing a configuration of a magneto-optical disk apparatus according to a second embodiment of the present invention.
FIG. 15 is a timing chart showing the operation of the magneto-optical disk apparatus of FIG. 14;
FIG. 16 is a diagram showing a recording power waveform in conventional pulse train recording;
[Explanation of symbols]
1 ... Magneto-optical disk device
2 ... Magneto-optical disk
3 ... Spindle motor
4. Optical pickup
6 ... LD
7 ... PD
8 ... LD driver
9 ... Head amp
10: Analog signal processing circuit
11 ... Drive controller
12 ... Amplitude detection circuit
13. Recording power calculation circuit
14 ... Memory circuit

Claims (1)

In an optical disc apparatus that sets a recording power of a laser beam at the time of data recording by irradiating a predetermined laser beam to a test area that is provided for each of a plurality of zones on the recording medium and configured by a plurality of sectors .
Laser control means for arbitrarily controlling the power of the laser beam;
Information reproducing means for reading and reproducing the recorded information on the recording medium recorded with the power;
Amplitude measuring means for measuring the amplitude of the reproduced signal reproduced by the information reproducing means;
Sequentially varying the predetermined the power for a given sector in the test area on the recording medium performs trial writing data by the laser control unit, the data of the predetermined sectors in the test area where the test writing has been made Recording power calculation means for performing amplitude measurement of the reproduction signal and calculating the recording power based on the test power that is the power when the amplitude measurement result falls within a predetermined range,
Test write prohibiting means for prohibiting the test write to the predetermined sector in the test area ;
With
The trial writing prohibition means includes:
A storage means for storing, as a trial write prohibited sector, a sector arranged at a position that inhibits amplitude measurement due to the influence of a signal of a predetermined sector in an adjacent zone during amplitude measurement among the sectors in the test area,
The optical disc apparatus characterized by prohibiting the trial writing to the trial write prohibited sector stored in the trial write prohibited sector storage means .

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