JP3676147B2 - Digital recording / reproducing device - Google Patents

Description

【０１２７】
ここで、「ＴＮＯ．」はトラックナンバーのことである。また、ＴＮＯ．１及びＴＮＯ．３は、高音質方式にて録音した曲を示しており、これらＴＮＯ．１及びＴＮＯ．３の奇数番目のサンプリングデータはＵＴＯＣセクタ０にて管理される。
【０１２８】
ＴＮＯ．１の奇数番目のサンプリングデータのスタートアドレスは「ａ０」、エンドアドレスは「ｂ０」である。
【０１２９】
また、ＴＮＯ．１の偶数番目のサンプリングデータはＵＴＯＣセクタ５にて管理される。ミニディスク３におけるＴＮＯ．１の偶数番目のサンプリングデータのスタートアドレスは「ａ５」、エンドアドレスは「ｂ５」である。
【０１３０】
また、ＴＮＯ．３の奇数番目のサンプリングデータのスタートアドレスは「ｅ０」、エンドアドレスは「ｆ０」である。
【０１３１】
さらに、ＴＮＯ．３の偶数番目のサンプリングデータはＵＴＯＣセクタ５にて管理される。ミニディスク３におけるＴＮＯ．３の偶数番目のサンプリングデータのスタートアドレスは「ｅ５」、エンドアドレスは「ｆ５」である。
【０１３２】
ＴＮＯ．２については、ＵＴＯＣセクタ５で管理されたデータが無く、通常録音された曲つまり従来方式にて録音された曲であり、ＵＴＯＣセクタ０のみで管理する。ＴＮＯ．２のディスクにおけるスタートアドレスは「ｃ０」、エンドアドレスは「ｄ０」である。
【０１３３】
上記のように、奇数番目のサンプリングデータと偶数番目のサンプリングデータとをＵＴＯＣセクタにて管理することにより、従来方式での再生に関しては、ＵＴＯＣセクタ０を確認しているので、ここにデータがあれば、通常のサンプリングにて記録したデータも、２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚによるサンプリングにて得たデータも再生可能となる。すなわち、いずれの方式にて記録したかにかかわらず、従来方式にて再生するときには、ＵＴＯＣセクタ５に関しては無視することになり、偶数領域にあるデータは再生しない。
【０１３４】
したがって、高音質方式によって記録したミニディスク３は、従来方式との互換性も兼ね備えることができている。ただし、２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚによってデータを得たミニディスク３の場合は、偶数領域分の記録可能時間が実質的に短縮されたことになる。
【０１３５】
また、このようなサンプリングにおける奇数項、偶数項毎に交互にミニディスク３のＡ記録領域３ａ又はＢ記録領域３ｂに記録する方法では、図５（ａ）に示すように、サンプリング周波数Ｆｓ＝８８．２ｋＨｚにてアナログ情報信号がディジタル変換されかつ圧縮された後、ミニディスク３におけるＡ記録領域３ａ又はＢ記録領域３ｂには、図５（ｂ）（ｃ）に示すように、それぞれサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて記録される。
【０１３６】
さらに、このように記録されたミニディスク３を再生したときには、図５（ｄ）に示すように、サンプリング周波数Ｆｓ＝８８．２ｋＨｚにて伸長され、アナログ情報信号に変換される。
【０１３７】
上記構成のＭＤ記録再生装置２０における再生動作について、図６及び図７に示すフローチャートに基づいて説明する。
【０１３８】
最初に、ミニディスク３に記録されたＵＴＯＣ情報を読み出すときには、図６に示すように、先ず、ピックアップ部１は、記録されたミニディスク３のＵＴＯＣ領域からＵＴＯＣセクタ０の読み出しを行う（Ｓ１）。
【０１３９】
次に、ＵＴＯＣセクタ５を使用しているか判定する（Ｓ２）。Ｓ２においてＵＴＯＣセクタ５を便用している場合は、ＵＴＯＣセクタ５を読み出す（Ｓ３）。
【０１４０】
一方、ＵＴＯＣセクタ５を使用していない場合は、ＵＴＯＣ読出しの中では何もせず、ＵＴＯＣ読出しフローから抜ける。
【０１４１】
次に、Ｓ３においてＵＴＯＣセクタ５を読み出した後、高音質方式にて録音されている曲の局番、スタートアドレス及びエンドアドレスをメモリ部８にてメモリする（Ｓ４）。
【０１４２】
以上のＵＴＯＣ読み出し手順を、振り分け情報記録手段としてのコントロール部９が信号処理部４をコントロールすることにより行う。
【０１４３】
次に、ミニディスク３を再生する時は、図７に示すように、先ず、キー入力部１４から高音質再生するか否かを入力する（Ｓ１１）。
【０１４４】
次いで、高音質再生する場合は、記録されたミニディスク３が高音質録音した曲か否かを前記メモリ部８に記憶されたデータにより判定する（Ｓ１２）。
【０１４５】
すなわち、高音質録音がされている場合はＵＴＯＣセクタ５にデータが記録されており、高音質録音がされていない場合はＵＴＯＣセクタ５にデータが記録されていない。このため、ＵＴＯＣセクタ５にデータが記録されているか否かによって、高音質録音がされているか否かを判定できる。
【０１４６】
上記Ｓ１１のキー入力において通常再生を指定した場合には、Ｓ１２においては、高音質録音された曲ではないとして、後述するＳ１７に移行する。
【０１４７】
なお、本フローチャートでは、Ｓ１１にてキー入力部１４から高音質再生するか否かの入力を行っているが、必ずしもこれに限らず、例えば、高音質再生を常に優先し、高音質録音されたミニディスク３は高音質再生しかしない場合は、Ｓ１１を省略し、Ｓ１２から開始しても良い。
【０１４８】
次に、上記Ｓ１２の高音質録音した曲か否かの判定結果により、信号処理部４内の伸長処理をするＡＴＲＡＣ部５、及びディジタルアナログコンバータ部７でのサンプリング周波数Ｆｓを設定する。すなわち、高音質録音した曲の場合はサンプリング周波数Ｆｓ＝８８．２ｋＨｚに設定し（Ｓ１３）、通常録音の場合はサンプリング周波数Ｆｓ＝４４．１ｋＨｚにそれぞれ設定をする（Ｓ１７）。これはフィルタデータ再生制御手段及びデータ連結制御手段としてのコントロール部９が行う。
【０１４９】
次に、高音質録音した曲の場合は、奇数番目、偶数番目のデータを一定ブロック毎に交互に読み込み、メモリ部８のＡ領域８ａ及びＢ記録領域３ｂのそれぞれに蓄積する（Ｓ１４）。なお、一定ブロックの容量は使用するメモリ部８の容量により決定する。
【０１５０】
次に、蓄積されたＵＴＯＣセクタ０のサンプリングデータである奇数番目のデータ及びＵＴＯＣセクタ５のサンプリングデータである偶数番目のデータをデータ連結制御手段としての信号処理部４にて元の順番に並び替える（Ｓ１５）。
【０１５１】
次に、元の順番に並び替えたデータを信号処理部４のＡＴＲＡＣ部５に入力し、圧縮されているデータの伸長処理を行う。ここでのＡＴＲＡＣ部５の動作は、設定されたサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて行われている。
【０１５２】
サンプリング周波数Ｆｓ＝８８．２ｋＨｚで動作しているＡＴＲＡＣ部５にて伸長されたディジタルデータは、ＡＴＲＡＣ部５と同様に、設定されたサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて動作しているディジタルアナログコンバータ部７に入力する。
【０１５３】
ディジタルアナログコンバータ部７に入力されたディジタルデータはここでアナログ信号に変換され、高音質再生を開始する（Ｓ１６）。
【０１５４】
一方、Ｓ１２にて高音質録音した曲でないと判断されたときには、上述のように、Ｓ１７にてサンプリング周波数Ｆｓを４４．１ｋＨｚに設定した後、ＵＴＯＣセクタ０管理のサンプリングデータを読み込み、メモリ部８におけるＡ領域８ａに蓄積する（Ｓ１８）。
【０１５５】
データが一定量蓄積されたら、Ｓ１６に移行して、メモリ部８に格納されたデータを再度読み出し、信号処理部４に入力する。信号処理部４にてサンプリング周波数Ｆｓ＝４４．１ｋＨｚに設定されたＡＴＲＡＣ部５において伸長処理をする。伸長されたデータはサンプリング周波数Ｆｓ＝４４．１ｋＨｚに設定されたディジタルアナログコンバータ部７にてオーディオアナログ信号に変換され、音の再生を開始する。
【０１５６】
通常再生の場合はサンプリング周波数Ｆｓ＝４４．１ｋＨｚであることにより、再生周波数は２０ｋＨｚになっている。
【０１５７】
ここで、前述したメモリ部８のＡ領域８ａにサンプリングにおける奇数項のデータを入れる際に、第２ローパスフィルタ部２１に通したことの意味が生じる。
【０１５８】
すなわち、この第２ローパスフィルタ部２１が無ければ、サンプリング周波数Ｆｓを４４．１ｋＨｚにすることによっての折り返し雑音の発生を抑えることができない。従来方式と同様にサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて再生できるように、サンプリングにおける奇数項のデータには格納する前に第２ローパスフィルタ部２１を通したのである。このことは、ミニディスク３のＡ記録領域３ａに記録した奇数項のデータには、周波数２０ｋＨｚ以上の成分は含まれていないものとして記録されている。
【０１５９】
この手法を取ることにより、従来方式での再生が可能になり高音質方式の再生用に記録したミニディスク３であっても再生時間は短くなるが再生可能になる。
【０１６０】
このように、本実施の形態のＭＤ記録再生装置２０では、ピックアップ部１及び磁気ヘッド部２は、ＡＴＲＡＣ部５によってミニディスク３の記録フォーマットに定めるサンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて圧縮されたディジタル情報信号を、サンプリング毎に順次交互にミニディスク３におけるＡ記録領域３ａとＢ記録領域３ｂとに振り分けて記録する。
【０１６１】
このため、それぞれにまとまりのあるデータを２つのＡ記録領域３ａとＢ記録領域３ｂとに振り分けることができる。その結果、Ａ記録領域３ａ及びＢ記録領域３ｂに記録したデータを別々に読み出すことができ、ミニディスク３からの読出しが簡易化される。したがって、データ管理を簡単にすることができる。また、データの読出しアクセスについても、データ記録領域が限定されるため、アクセス時間を早くすることができる。
【０１６２】
ところで、主情報をミニディスク３におけるＡ記録領域３ａとＢ記録領域３ｂとに振り分けて記録したときには、管理データの付加情報をすぐに読み出せる場所に記録しておくのが好ましい。
【０１６３】
これに対し、本実施の形態では、コントロール部９が、ミニディスク３におけるＡ記録領域３ａ又はＢ記録領域３ｂに記録されたディジタル情報信号を管理する付加情報をミニディスク３のＵＴＯＣ領域３ｄに記録する。
【０１６４】
したがって、管理データの付加情報を主情報を記録する録音用ユーザ領域３ｃとは異なる場所に記録することにより、情報と管理データとの区別を簡易化してミニディスク３に記録された情報を早く入手でき、処理時間を短縮することができる。
【０１６５】
また、本実施の形態のＭＤ記録再生装置２０では、ミニディスク３にサンプリング毎に順次交互にＡ記録領域３ａとＢ記録領域３ｂとに振り分けて記憶されたディジタル情報信号のうち、少なくとも一方のＡ記録領域３ａは第２ローパスフィルタ部２１を介したデータである。
【０１６６】
このため、少なくとも一方はミニディスク３の記録フォーマットに定めるサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて記録する時と同様の周波数帯域にすることができるので、同程度のデータを２箇所に記録したこととならず、ミニディスク３の利用方法も拡大される。
【０１６７】
さらに、逆に、他方をナイキスト周波数（２０ｋＨｚ）以上のデータを含むようにすることができるので、高音質方式による再生も可能となる。
【０１６８】
また、本実施の形態のＭＤ記録再生装置２０では、コントロール部９は、上記所定のサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて再生するときに、第２ローパスフィルタ部２１を介したデータのみを再生させる。
【０１６９】
このため、サンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにてサンプリングした信号を、サンプリング周波数Ｆｓ＝４４．１ｋＨｚにて再生できる。すなわち、このことは、サンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて記録されたミニディスク３を従来機にて再生可能であることを意味し、これによって、ミニディスク３の互換性を確実に保つことができる。ただし、再生時間は、従来方式にてミニディスク３に記録された時間よりは短縮される。
【０１７０】
また、本実施の形態のＭＤ記録再生装置２０では、ミニディスク３の記録フォーマットに定めるサンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにてディジタル化しかつ圧縮したディジタル情報信号を記録したミニディスク３を、上記所定のサンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて再生するときには、コントロール部９が、ミニディスク３におけるＡ記録領域３ａのデータとＢ記録領域３ｂのデータとを元の順序に並び替え、所定のサンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにてＡＴＲＡＣ部５及びディジタルアナログコンバータ部７を動作させる。
【０１７１】
このため、所定のサンプリング周波数Ｆｓ＝４４．１ｋＨｚの２倍のサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて記録されたミニディスク３を再生するときには、記録された手法の逆手順の再生動作をさせるだけで、高音質再生が可能となる。
【０１７２】
【発明の効果】
本発明のディジタル記録再生装置は、以上のように、所定のサンプリング周波数の整数倍のサンプリング周波数にてアナログ情報信号をディジタル情報信号に変換するディジタル化手段と、上記ディジタル化手段にてディジタル化されたディジタル情報信号を、上記所定のサンプリング周波数の整数倍のサンプリング周波数にて圧縮する圧縮手段と、上記圧縮手段にて圧縮されたディジタル情報信号を、サンプリング毎に順次交互に上記記録媒体における第一の記録領域と第二の記録領域とに振り分けて上記所定のサンプリング周波数にて記録する記録手段とが備えられているものである。
【０１７３】
それゆえ、アナログ情報信号を従来の記録媒体にて規定される所定のサンプリング周波数の整数倍のサンプリング周波数にてディジタルに変換するので、整数倍のサンプリング周波数にてディジタルに変換したときには、その１／整数倍の周波数までの高周波領域のアナログ情報信号を変換することができる。この結果、従来よりも、約整数倍の高周波領域のアナログ情報信号を変換することが可能となる。
【０１７４】
また、広帯域のデータを含んだ状態であっても、記録媒体に記録する時は、所定のサンプリング周波数にて記録できる。すなわち、従来の記録手法を利用し、複雑な信号処理手段を設けることなく高周波領域まで記録できるものとなっているので、装置内の変更要素を少なくして高音質を確保することができる。
【０１７５】
したがって、記録媒体への書き込みにおける従来方式との互換性を確保しつつ、複雑な信号処理等を行うことを回避して、アナログ波形をより忠実に再現して音質の向上を図り得るディジタル記録再生装置を提供することができるという効果を奏する。
【０１７６】
また記録手段は、圧縮手段によって所定のサンプリング周波数の整数倍のサンプリング周波数にて圧縮されたディジタル情報信号を、サンプリング毎に順次交互に記録媒体における第一の記録領域と第二の記録領域とに振り分けて記録する。
【０１７７】
それゆえ、それぞれにまとまりのあるデータを２つの第一の記録領域と第二の記録領域とに振り分けることができる。その結果、第一の記録領域及び第二の記録領域に記録したデータを別々に読み出すことができ、記録媒体からの読出しが簡易化される。したがって、データ管理を簡単にすることができる。また、データの読出しアクセスについても、データ記録領域が限定されるため、アクセス時間を早くすることができるという効果を奏する。
【０１７８】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、記録媒体から所定のサンプリング周波数にてディジタル情報信号を読み取る読取手段と、上記読取手段により読み取ったディジタル情報信号を上記所定のサンプリング周波数の整数倍のサンプリング周波数にて伸長する伸長手段と、上記伸長手段により伸長されたディジタル情報信号を、上記所定のサンプリング周波数の整数倍のサンプリング周波数にてアナログ情報信号に変換するアナログ化手段とが備えられているものである。
【０１７９】
それゆえ、記録媒体に所定のサンプリング周波数で記録されたデータを読出し、所定のサンプリング周波数の整数倍にて伸長した後、ディジタルアナログ変換して高音質再生することができる。
【０１８０】
そして、再生に関しても、従来機と同様の周波数で記録媒体から読み出すため、従来機からの機器内部の変更点を少なくして、高音質の再生を可能とすることができる。
【０１８１】
したがって、記録媒体への読み取りにおける従来方式との互換性を確保しつつ、複雑な信号処理等を行うことを回避して、アナログ波形をより忠実に再現して音質の向上を図り得るディジタル記録再生装置を提供することができるという効果を奏する。
【０１８２】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、所定のサンプリング周波数の整数倍のサンプリング周波数にてディジタル化しかつ圧縮したディジタル情報信号を記録した記録媒体であることを、該記録媒体に主情報とは別個に付加情報として記録するサンプリング情報記録手段が備えられているものである。
【０１８３】
それゆえ、再生するときに、付加情報を参照すれば、高音質方式にて記録されたことが判断できるので、高音質方式にて適切に再生することができる。
【０１８４】
また、このことにより、記録媒体の内容を主情報の再生をするまでもなく読み取ることができ、従来方式では再生しないように制御することができる。
【０１８５】
この結果、記録媒体への書き込み及び読み取りにおける従来方式との互換性を確保しつつ、複雑な信号処理等を行うことを回避して、アナログ波形をより忠実に再現して音質の向上を図り得るディジタル記録再生装置を提供することができるという効果を奏する。
【０１８６】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、サンプリング情報記録手段にて付加情報を記録した記録媒体から付加情報が得られたときは、所定のサンプリング周波数の整数倍のサンプリング周波数にて伸長手段及びアナログ化手段を動作させる付加情報動作制御手段が備えられているものである。
【０１８７】
それゆえ、記録媒体に記録された付加情報により、どのようなサンプリング周波数で記録されているかを外部からわざわざインプットすることなく、適正なサンプリング周波数に設定することができる。つまり、マニュアルにて従来方式にて記録された記録媒体か又は高音質方式にて記録された記録媒体かを判断することなく、最適再生が可能となる。また、誤って異なったサンプリング周波数にて再生することを防ぐこともできるという効果を奏する。
【０１８８】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、記録媒体における第一の記録領域又は第二の記録領域に記録されたディジタル情報信号を管理する付加情報を記録媒体の例えばＵＴＯＣ等の第三の記録領域に記録する振り分け情報記録手段が備えられているものである。
【０１８９】
それゆえ、管理データの付加情報を主情報を記録する場所とは異なる場所に記録することにより、情報と管理データとの区別を簡易化して記録媒体に記録された情報を早く入手でき、処理時間を短縮することができるという効果を奏する。
【０１９０】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、記録媒体にサンプリング毎に順次交互に第一の記録領域と第二の記録領域とに振り分けて記憶されたディジタル情報信号のうち、少なくとも一方はフィルタを介したデータであるものである。
【０１９１】
それゆえ、少なくとも一方は所定のサンプリング周波数にて記録する時と同様の周波数帯域にすることができるので、同程度のデータを２箇所に記録したこととならず、記録媒体の利用方法も拡大される。
【０１９２】
また、逆に、他方をナイキスト周波数以上のデータを含むようにすることができるので、高音質方式による再生も可能となるという効果を奏する。
【０１９３】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、所定のサンプリング周波数にて再生するときに、フィルタを介したデータのみを再生させるフィルタデータ再生制御手段が備えられているものである。
【０１９４】
それゆえ、所定のサンプリング周波数の整数倍のサンプリング周波数にてサンプリングした信号を、所定のサンプリング周波数にて再生できる。すなわち、このことは、所定のサンプリング周波数の整数倍のサンプリング周波数にて記録された記録媒体を従来機にて再生可能であることを意味し、これによって、記録媒体への書き込み及び読み取りにおける互換性を確実に保つことができるという効果を奏する。
【０１９５】
本発明のディジタル記録再生装置は、以上のように、上記記載のディジタル記録再生装置において、所定のサンプリング周波数の整数倍のサンプリング周波数にてディジタル化しかつ圧縮したディジタル情報信号を記録した記録媒体を、上記所定のサンプリング周波数の整数倍のサンプリング周波数にて再生するときには、記録媒体における第一の記録領域のデータと第二の記録領域のデータとを元の順序に並び替え、所定のサンプリング周波数の整数倍のサンプリング周波数にて伸長手段及びアナログ化手段を動作させるデータ連結制御手段が備えられているものである。
【０１９６】
それゆえ、所定のサンプリング周波数の整数倍のサンプリング周波数にて記録された記録媒体を再生するときには、記録された手法の逆手順の再生動作をさせるだけで、高音質再生が可能となるという効果を奏する。
【図面の簡単な説明】
【図１】 本発明の基になる参考例を示すブロック図である。
【図２】 上記参考例の回路ブロックにおける各ポジションでの信号を示す概念波形図であり、（ａ）は情報信号をサンプリング周波数Ｆｓ＝８８．２ｋＨｚによるサンプリングにて動作してディジタル化するアナログディジタルコンバータ部及び圧縮を行うＡＴＲＡＣ部での概念波形を示すもの、（ｂ）はミニディスクにサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて記録された概念波形を示すもの、（ｃ）は情報信号をサンプリング周波数Ｆｓ＝８８．２ｋＨｚにて動作して伸長を行うＡＴＲＡＣ部及びアナログ変換するディジタルアナログコンバータ部での概念波形を示すものである。
【図３】 本発明におけるＭＤ記録再生装置の実施の形態を示すブロック図である。
【図４】 上記ＭＤ記録再生装置にてサンプリングの奇数項と偶数項とを振り分けて記録されるミニディスクの構造を示す平面図である。
【図５】 上記ＭＤ記録再生装置の回路ブロックにおける各ポジションでの信号を示す概念波形図であり、（ａ）は情報信号をサンプリング周波数Ｆｓ＝８８．２ｋＨｚによるサンプリングにて動作してディジタル化するアナログディジタルコンバータ部及び圧縮を行うＡＴＲＡＣ部での概念波形を示すもの、（ｂ）はミニディスクのＡ記録領域にサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて記録された奇数番目のサンプリングの概念波形を示すもの、（ｃ）はミニディスクのＢ記録領域にサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて記録された偶数番目のサンプリングの概念波形を示すもの、（ｄ）は奇数番目と偶数番目とを合わせた情報信号をサンプリング周波数Ｆｓ＝８８．２ｋＨｚにより動作して伸長を行うＡＴＲＡＣ
部及びアナログ変換するディジタルアナログコンバータ部での概念波形を示すものである。
【図６】 上記ＭＤ記録再生装置において高音質方式にて記録されたミニディスクを読み出すときの動作を示すフローチャートである。
【図７】 上記ＭＤ記録再生装置において高音質方式にて記録されたミニディスクを読み出した後、再生するときの動作を示すフローチャートである。
【図８】 （ａ）（ｂ）はアナログ音響信号波形のディジタル処理手順を示す説明図である。
【図９】 従来のＭＤ記録再生装置を示すブロック図である。
【図１０】 上記ＭＤ記録再生装置の回路ブロックにおける各ポジションでの信号を示す概念波形図であり、（ａ）は情報信号をサンプリング周波数Ｆｓ＝４４．１ｋＨｚによるサンプリングにて動作してディジタル化するアナログディジタルコンバータ部及び圧縮を行うＡＴＲＡＣ部での概念波形を示すもの、（ｂ）はミニディスクに同様にサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて記録された概念波形を示すもの、（ｃ）は情報信号を同様にサンプリング周波数Ｆｓ＝４４．１ｋＨｚにて動作して伸長を行うＡＴＲＡＣ部及びアナログ変換するディジタルアナログコンバータ部での概念波形を示すものである。
【符号の説明】
１ ピックアップ部（記録手段、読取手段）
２ 磁気ヘッド部（記録手段）
３ ミニディスク（記録媒体）
３ａ Ａ記録領域（第一の記録領域）
３ｂ Ｂ記録領域（第二の記録領域）
３ｃ 録音用ユーザ領域（主情報を記録する場所）
３ｄ ＵＴＯＣ領域（第三の記録領域）
４ 信号処理部（データ連結制御手段）
５ ＡＴＲＡＣ部（圧縮手段、伸長手段）
６ アナログディジタルコンバータ〔ＡＤＣ〕部（ディジタル化手段）
７ ディジタルアナログコンバータ〔ＤＡＣ〕部（アナログ化手段）
８ メモリ部
８ａ Ａ領域
８ｂ Ｂ領域
９ コントロール部（サンプリング情報記録手段、付加情報動作制御手段、
振り分け情報記録手段、フィルタデータ再生制御手段
、データ連結制御手段）
１０ ＭＤ記録再生装置
２０ ＭＤ記録再生装置
２１ 第２ローパスフィルタ部（フィルタ）[0001]
BACKGROUND OF THE INVENTION
  The present invention provides a digital information signal obtained by converting an analog information signal into a digitized digital signal and recording or reproducing the digital information signal on the recording medium at a predetermined sampling frequency determined on a recording medium such as an MD (mini disk). The present invention relates to a recording / reproducing apparatus, and more particularly, to improvement of sound quality characteristics in a high frequency region.
[0002]
[Prior art]
  Audio compact discs (CD) and mini discs (MD) record analog sound signal waveforms converted to digital.
[0003]
  When the analog signal is converted into a digital signal, as shown in FIGS. 8A and 8B, the original waveform is selected depending on how fine the time interval of the acoustic signal is sampled and how accurately it is read. Only the faithful reproduction is determined.
[0004]
  How finely the horizontal axis of the acoustic signal waveform is divided is called sampling or sampling. In particular, the number read per second is called sampling frequency or sampling frequency Fs.
[0005]
  As described above, in order to reproduce the waveform more faithfully, it is necessary to read it in such a manner that the change can be traced finely. In order to establish the standard, the sampling frequency Fs is generally set to at least twice the frequency of the sound wave to be reproduced using an information theory called sampling theorem. That is, if the sampling frequency Fs is determined to be 48 kHz (for example, the sound wave waveform for 1 second is divided into 48000 and read), 24 kHz corresponding to a half thereof becomes the upper limit of the reproduction frequency range. Therefore, acoustic signals below this frequency can be reproduced, but frequencies above this cannot be reproduced.
[0006]
  By the way, in the conventional audio compact disc and mini disc (MD), the sampling frequency Fs when recording is set as a format of 44.1 kHz, so the reproduction frequency is 20 kHz in consideration of the filter characteristics. Yes.
[0007]
  However, for the past several years, it has been reported that frequency components of 20 kHz or higher have an effect on human audio signal perception. For this reason, a technique has been disclosed that has a commonality with a conventional machine in which the sampling frequency Fs is set to 44.1 kHz and can also reproduce high-frequency components.
[0008]
  For example, in the technique disclosed in Japanese Patent Laid-Open No. 6-342558, an audio signal digitized at a sampling frequency Fs = 44.1 kHz is recorded in an audio area for a CD or DA (Digital Audio). Then, an information signal in a band equal to or higher than the Nyquist frequency (22.05 kHz) is extracted using a filter or the like, and further compression-coded and recorded in the subcode area.
[0009]
  As a result, a high-quality audio signal can be reproduced by reproducing both the data recorded in the subcode area and the data in the conventional audio area. In the technique of this publication, normal reproduction is also possible by reproducing only the audio area.
[0010]
  In the conventional general MD recording / reproducing apparatus, as shown in FIG. 9, during recording, an audio input signal is converted from an analog signal to a digital signal by an analog / digital converter (ADC) unit 56 at a sampling frequency Fs = 44.1 kHz. Convert to
[0011]
  The digitally converted signal is compressed at the same sampling frequency Fs = 44.1 kHz by the ATRAC (Adaptive Transform Acoustic Coding) method in the ATRAC unit 55 which is a compression / decompression circuit unit in the signal processing unit 54. The data is stored in a memory unit (DRAM: Dynamic Random Access Memory) 58.
[0012]
  Next, the data stored in the memory unit 58 is sequentially recorded on the disk 53 via the magnetic head 52 at the same sampling frequency Fs = 44.1 kHz.
[0013]
  On the other hand, at the time of reproduction, the signal recorded on the disk 53 is read by the pickup unit 51 at the sampling frequency Fs = 44.1 kHz and input to the signal processing unit 54. Data input to the signal processing unit 54 is temporarily stored in the memory unit 58 and sequentially input to the ATRAC unit 55. Next, the compressed data is expanded at the sampling frequency Fs = 44.1 kHz by the ATRAC unit 55 and input to the digital analog converter (DAC) unit 57. The digital / analog converter unit 57 converts the digital signal into an analog signal at the sampling frequency Fs = 44.1 kHz, thereby obtaining an audio output signal.
[0014]
  The above recording / playback operations are realized by the control unit 59 controlling the signal processing unit 54.
[0015]
  In the above circuit, as described above, the sampling frequencies of the analog-digital converter unit 56, the ATRAC unit 55, and the digital-analog converter unit 57 all operate at 44.1 kHz. Therefore, the ADC unit 56, the data actually recorded on the disk 53, and the conceptual waveform of the DAC unit 57 are as shown in FIGS. 10 (a), 10 (b), and 10 (c). Hereinafter, this analog-digital conversion at the sampling frequency Fs = 44.1 kHz is referred to as a conventional method.
[0016]
[Problems to be solved by the invention]
  However, in the conventional digital recording / reproducing apparatus disclosed in the above publication, the sampling frequency of a normal music signal is set to 44.1 kHz for compatibility with the conventional system, and the Nyquist frequency (22.05 kHz) Since the recordable area is limited as described above, it is necessary to increase the compression rate so as to enter the recordable area.
[0017]
  In addition to changing the sampling frequency Fs in order to obtain a signal with a Nyquist frequency (22.05 kHz) or higher, a circuit for extracting a signal with a Nyquist frequency or higher is required, and the amount of data extracted can be recorded. Complicated management such as selecting the compression method by comparing with the recordable amount in the area has occurred. Therefore, as a matter of course, when there is a large amount of data at the Nyquist frequency (22.05 kHz) or more, the recordable area cannot be made variable, so it is necessary to rely on a high compression rate.
[0018]
  However, when the compression rate cannot be varied, it is necessary to reduce the data amount by a technique such as band division and weighting by bit allocation. That is, there is a problem that more complicated signal processing or the like needs to be performed.
[0019]
  Further, in the MD recording / reproducing apparatus, similarly to the CD recording / reproducing apparatus, the sampling frequency Fs is fixed to 44.1 kHz, so that the band of the compressed signal to be recorded is limited to 20 kHz. Therefore, in the recording / reproduction from wideband data such as DVD and SACD that have been recently standardized, all bands with a frequency of 20 kHz or higher are cut and recorded due to the sampling frequency Fs, even though there is wideband data. As a result, there is a problem that many dissatisfactions in terms of sound quality are seen.
[0020]
  The present invention has been made in view of the above-described conventional problems, and its purpose is to perform complex signal processing and the like while ensuring compatibility with conventional methods for writing to and reading from a recording medium. It is an object of the present invention to provide a digital recording / reproducing apparatus capable of avoiding the analog waveform more faithfully and improving the sound quality.
[0021]
[Means for Solving the Problems]
  In order to solve the above-described problems, the digital recording / reproducing apparatus of the present invention has a predetermined sampling frequency, for example, in which a digital information signal obtained by converting an analog information signal into a digital signal is defined on a recording medium such as a mini disk (MD). In a digital recording / reproducing apparatus for recording on or reproducing from a recording medium at a sampling frequency Fs = 44.1 kHz, an analog information signal is converted into a digital information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency. Digitizing means for converting, compressing means for compressing the digital information signal digitized by the digitizing means at a sampling frequency that is an integral multiple of the predetermined sampling frequency, and digital compressed by the compressing means Information signal, And assign them alternately to the first recording area and the second recording area of the recording medium in turn for each sampling.And recording means for recording at the predetermined sampling frequency.
[0022]
  According to the above invention, the digital recording / reproducing apparatus determines the digital information signal obtained by converting the analog information signal and digitizing it as a recording format on a recording medium such as a mini-disc (MD), for example. Recording on or reproducing from the recording medium at 1 kHz.
[0023]
  Here, when recording an analog information signal on a recording medium such as a mini disk (MD), first, the digitizing means outputs the analog information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency Fs = 44.1 kHz. Convert to digital information signal.
[0024]
  That is, when an analog information signal is digitized, it can be converted only up to about a half of the sampling frequency Fs. Conventionally, analog information in a higher frequency region than a frequency of about 20 kHz is considered in consideration of filter characteristics and the like. The signal could not be converted.
[0025]
  However, in the present invention, the analog information signal is converted to digital at a sampling frequency that is an integral multiple of a predetermined sampling frequency = 44.1 kHz defined by a conventional minidisc (MD) or the like. Therefore, when digital conversion is performed at a sampling frequency Fs = 88.2 kHz which is twice as an integral multiple, for example, an analog information signal in a high frequency region up to a frequency of 44.1 kHz can be converted. As a result, it is possible to convert an analog information signal in a high frequency region that is approximately twice as high as that in the prior art.
[0026]
  Next, the digital information signal converted at a sampling frequency that is an integral multiple of the predetermined sampling frequency is similarly compressed by the compression means at a sampling frequency that is an integral multiple of the predetermined sampling frequency.
[0027]
  The compressed digital information signal is then recorded on the recording medium by the recording means at a sampling frequency Fs = 44.1 kHz, which is a predetermined sampling frequency determined for the recording medium such as a mini disk (MD). The Therefore, since recording is performed at a sampling frequency Fs = 44.1 kHz, which is a predetermined sampling frequency defined for the recording medium, on a recording medium such as a mini disk (MD), recording can be performed without any problem.
[0028]
  As a result, even when the data includes broadband data, it can be recorded at a predetermined sampling frequency when recording on a recording medium. That is, since the conventional recording technique can be used and recording can be performed up to the high frequency region without providing complicated signal processing means, high quality can be ensured by reducing the number of changing elements in the apparatus.
[0029]
  Therefore, digital recording and playback that can improve the sound quality by reproducing analog waveforms more faithfully while avoiding complicated signal processing while ensuring compatibility with conventional methods for writing to recording media An apparatus can be provided.
[0030]
  According to the invention described above, the recording means converts the digital information signal compressed by the compression means at a sampling frequency that is an integral multiple of a predetermined sampling frequency alternately with the first recording area and the first recording area of the recording medium every sampling. The recording is divided into two recording areas.
[0031]
For this reason, it is possible to distribute the data that is grouped into the two first recording areas and the second recording area. As a result, data recorded in the first recording area and the second recording area can be read separately, and reading from the recording medium is simplified. Therefore, data management can be simplified. Also, for data read access, the access time can be shortened because the data recording area is limited.
[0032]
  In order to solve the above problems, a digital recording / reproducing apparatus of the present invention is the above-described digital recording / reproducing apparatus, wherein the digital information signal is read from a recording medium at a predetermined sampling frequency, and the reading means reads the digital information signal. Extending means for expanding a digital information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency; and converting the digital information signal expanded by the expanding means into analog information at a sampling frequency that is an integral multiple of the predetermined sampling frequency. An analog means for converting into a signal is provided.
[0033]
  According to the invention, the reading means for reading the digital information signal from the recording medium at a predetermined sampling frequency, and the expansion for expanding the digital information signal read by the reading means at a sampling frequency that is an integral multiple of the predetermined sampling frequency. Means for converting the digital information signal expanded by the expansion means into an analog information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency.
[0034]
  That is, when reproducing a recording medium recorded by the above-described high sound quality digital recording / reproducing apparatus, first, the reading means reads digital information from the recording medium at a predetermined sampling frequency, for example, sampling frequency Fs = 44.1 kHz. Read the signal. Since this reading is performed at a sampling frequency Fs = 44.1 kHz, which is a predetermined sampling frequency of the recording medium, it can be read without any problem.
[0035]
  Next, the digital information signal read by the reading unit is expanded by the expansion unit at a sampling frequency that is an integral multiple of a predetermined sampling frequency. Further, the digital information signal decompressed by the decompressing means is converted into an analog information signal at a sampling frequency that is an integral multiple of a predetermined sampling frequency by the analogizing means.
[0036]
  As a result, the data recorded on the recording medium at a predetermined sampling frequency can be read out, expanded at an integer multiple of the predetermined sampling frequency, and then converted to digital to analog for high-quality reproduction.
[0037]
  As for reproduction, since the data is read from the recording medium at the same frequency as that of the conventional device, it is possible to reduce the number of changes in the device from the conventional device and to reproduce the sound with high sound quality.
[0038]
  Therefore, digital recording and playback that can improve the sound quality by reproducing analog waveforms more faithfully while avoiding complicated signal processing while ensuring compatibility with conventional methods for reading to recording media An apparatus can be provided.
[0039]
  In order to solve the above problems, a digital recording / reproducing apparatus of the present invention is a recording method in which a digital information signal digitized and compressed at a sampling frequency that is an integral multiple of a predetermined sampling frequency is recorded in the digital recording / reproducing apparatus described above. Sampling information recording means for recording as additional information separately from main information on the recording medium is provided.
[0040]
  That is, even in a high sound quality system in which an information signal converted into a digital information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency and recorded on the recording medium is recorded on the recording medium, the normal predetermined sampling frequency is set. Recorded. For this reason, unless the information recorded by the high sound quality method is recorded in, for example, the UTOC area of the recording medium, it cannot be properly reproduced by the high sound quality method.
[0041]
  However, according to the present invention, the additional information separately from the main information is recorded on the recording medium in which the digital information signal digitized and compressed at a sampling frequency that is an integral multiple of the predetermined sampling frequency is recorded. Sampling information recording means for recording as follows.
[0042]
  Therefore, when the reproduction is performed, it can be determined that the recording is performed by the high sound quality method by referring to the additional information. Therefore, the reproduction can be appropriately performed by the high sound quality method.
[0043]
  In addition, this makes it possible to read the content of the recording medium without reproducing the main information, and control so as not to reproduce in the conventional method.
[0044]
  As a result, it is possible to improve the sound quality by reproducing the analog waveform more faithfully while avoiding complicated signal processing and the like while ensuring compatibility with the conventional method for writing to and reading from the recording medium. A digital recording / reproducing apparatus can be provided.
[0045]
  In order to solve the above-mentioned problems, the digital recording / reproducing apparatus of the present invention provides a digital recording / reproducing apparatus described above, wherein additional information is obtained when the additional information is obtained from the recording medium on which the additional information is recorded by the sampling information recording means. The additional information operation control means for operating the decompression means and the analogization means at a sampling frequency that is an integral multiple of the sampling frequency is provided.
[0046]
  According to the above invention, when the additional information is obtained from the recording medium on which the additional information is recorded by the sampling information recording means, the additional information operation control means is the expansion means at a sampling frequency that is an integral multiple of the predetermined sampling frequency. And the analog means is operated.
[0047]
  Therefore, it is possible to set an appropriate sampling frequency without input from the outside what kind of sampling frequency is recorded by the additional information recorded on the recording medium. In other words, optimum reproduction is possible without manually determining whether the recording medium is recorded by the conventional method or the recording medium recorded by the high sound quality method. In addition, it is possible to prevent reproduction at a different sampling frequency by mistake.
[0048]
  In order to solve the above problems, the digital recording / reproducing apparatus of the present invention manages the digital information signal recorded in the first recording area or the second recording area of the recording medium in the above-described digital recording / reproducing apparatus. The distribution information recording means for recording the additional information in a third recording area such as UTOC of the recording medium is provided.
[0049]
  That is, when the main information is divided and recorded in the first recording area and the second recording area on the recording medium, it is preferable to record the additional information of the management data in a place where it can be read out immediately.
[0050]
  On the other hand, in the present invention, the distribution information recording means transmits the additional information for managing the digital information signal recorded in the first recording area or the second recording area of the recording medium to the third information such as UTOC of the recording medium. In the recording area.
[0051]
  Therefore, by recording the additional information of the management data in a location different from the location where the main information is recorded, the information recorded on the recording medium can be obtained quickly by simplifying the distinction between the information and the management data, and the processing time can be reduced. It can be shortened.
[0052]
  In order to solve the above-described problems, the digital recording / reproducing apparatus of the present invention is the digital recording / reproducing apparatus described above, in which the recording medium is sequentially assigned to the first recording area and the second recording area alternately for each sampling. At least one of the stored digital information signals is data that has passed through a filter.
[0053]
  According to the above-described invention, at least one of the digital information signals stored in the recording medium after being alternately and alternately allocated to the first recording area and the second recording area for each sampling is data through the filter.
[0054]
  For this reason, since at least one can be set to the same frequency band as when recording at a predetermined sampling frequency, the same level of data is not recorded in two places, and the method of using the recording medium is expanded. The
[0055]
  On the other hand, since the other can include data having a frequency higher than the Nyquist frequency, reproduction by a high sound quality system is also possible.
[0056]
  In order to solve the above problems, the digital recording / reproducing apparatus of the present invention is a filter data reproduction control for reproducing only data through a filter when reproducing at a predetermined sampling frequency in the digital recording / reproducing apparatus described above. Means are provided.
[0057]
  According to the above invention, the filter data reproduction control means reproduces only the data that has passed through the filter when reproducing at a predetermined sampling frequency.
[0058]
  For this reason, a signal sampled at a sampling frequency that is an integral multiple of the predetermined sampling frequency can be reproduced at the predetermined sampling frequency. In other words, this means that a recording medium recorded at a sampling frequency that is an integral multiple of the predetermined sampling frequency can be reproduced on a conventional machine, thereby ensuring the compatibility of the recording medium. Can do. However, the reproduction time is shorter than the time recorded on the recording medium by the conventional method.
[0059]
  In order to solve the above problems, a digital recording / reproducing apparatus of the present invention is a recording method in which a digital information signal digitized and compressed at a sampling frequency that is an integral multiple of a predetermined sampling frequency is recorded in the digital recording / reproducing apparatus described above. When reproducing the medium at a sampling frequency that is an integral multiple of the predetermined sampling frequency, the data in the first recording area and the data in the second recording area on the recording medium are rearranged in the original order, and the predetermined sampling is performed. Data connection control means for operating the decompression means and the analogization means at a sampling frequency that is an integral multiple of the frequency is provided.
[0060]
  According to the invention, when a recording medium on which a digital information signal digitized and compressed at a sampling frequency that is an integral multiple of a predetermined sampling frequency is reproduced at a sampling frequency that is an integral multiple of the predetermined sampling frequency, The data connection control means rearranges the data in the first recording area and the data in the second recording area in the original order in the recording medium, and expands and analogizes the data at a sampling frequency that is an integral multiple of a predetermined sampling frequency. Operate means.
[0061]
  For this reason, when reproducing a recording medium recorded at a sampling frequency that is an integral multiple of a predetermined sampling frequency, high-quality sound reproduction can be performed only by performing a reproduction operation in the reverse procedure of the recorded method.
[0062]
DETAILED DESCRIPTION OF THE INVENTION
    [Reference example]
  Of the present inventionBasic reference examples1 will be described with reference to FIGS. 1 and 2 as follows.
[0063]
  BookReference exampleThe MD (mini-disc) recording / reproducing apparatus as a digital recording / reproducing apparatus of the above-described digital recording / reproducing apparatus maintains compatibility with the recording format of the conventional mini-disc (MD) in which recording is performed at the sampling frequency Fs = 44.1 kHz. This is a device for recording or reproducing a signal whose sound quality is improved as compared with a conventional mini-disc signal.
[0064]
  As shown in FIG. 1, the MD recording / reproducing apparatus 10 includes an input unit 12 for inputting an audio signal, a first low-pass filter (LPF) 11 for cutting the Nyquist frequency or higher, and an analog signal as a digital signal. An analog-to-digital converter (ADC) unit 6 as a digitizing means for conversion, a signal processing unit 4 for processing a digital signal or changing a transmission format, and reading a signal from a mini-disc 3 as a recording medium In order to record data on the mini-disc 3 at the time of recording, a pickup unit 1 as a recording means and a reading means for raising a temperature in a predetermined range of a writing area on the mini-disc 3 by laser light, and the pickup unit 1 The magnetic domain at the point where the temperature of the writing part of the mini-disc 3 was raised by irradiation of A magnetic head unit 2 as recording means for recording, and a memory unit 8 comprising a DRAM (Dynamic Random Access Memory) or the like for temporarily storing compressed data for recording or temporarily storing data read from the mini-disc 3 A control unit 9 as a sampling information recording means and an additional information operation control means comprising a microcomputer for controlling each part and converting the sampling frequency Fs, etc., and an ATRAC (Adaptive Transform Acoustic Coding) as a compression means and an expansion means A digital-analog converter unit 7 serving as an analog means for converting the digital data expanded by the unit 5 into analog data, an output unit 13 for outputting a signal converted into an analog signal, and external control contents are input. It consists of a key input unit 14.
[0065]
  The signal processing unit 4 includes a circuit for compressing or expanding a digital signal, and the ATRAC unit 5 is responsible for the mini-disc system. The ATRAC unit 5 performs digital signal compression or expansion processing by the ATRAC method. Here, the ATRAC system employed in the ATRAC unit 5 is a signal compression / decompression system proposed by Sony Corporation.
[0066]
  Since there are other systems for compressing or expanding digital signals, the digital signal compression / decompression system may be determined by the system configuration method and is not limited to the ATRAC system.
[0067]
  Next, the operation of the MD recording / reproducing apparatus 10 having the above configuration will be described along the flow of signals.
[0068]
  First, an input signal to the MD recording / reproducing apparatus 10 is an analog continuous signal such as an audio signal or an acoustic signal. When this continuous signal is input to the input unit 12 of the MD recording / reproducing apparatus 10, it is input to the first low-pass filter unit 11, which is the next step.
[0069]
  The first low-pass filter unit 11 cuts a frequency band equal to or higher than the Nyquist frequency in order to prevent aliasing noise during AD conversion.
[0070]
  Here, this Nyquist frequency isReference exampleThen, since the sampling frequency Fs in the analog-digital converter unit 6 is 88.2 kHz, the frequency is half that of 44.1 kHz. Ie bookReference exampleIn this case, the analog information signal can be recorded up to a frequency of 44.1 kHz, and can be recorded up to about twice the high frequency region as compared with a conventional signal that can be recorded only up to a frequency of 20 kHz. Hereinafter, a method capable of recording up to a frequency of 44.1 kHz will be referred to as a high sound quality method, and a method capable of recording only up to a frequency of 20 kHz will be referred to as a conventional method.
[0071]
  The analog acoustic signal whose frequency band equal to or higher than the Nyquist frequency is cut is input to the analog-digital converter unit 6.
[0072]
  The sampling frequency Fs of the analog / digital converter unit 6 is controlled by the control unit 9. Here, in the conventional method, the sampling frequency Fs in the analog-digital converter unit 6 is derived from the format of the mini-disc 3 and is 44.1 kHz as a predetermined sampling frequency.
[0073]
  But bookReference exampleIn this case, the sampling frequency Fs of the analog-digital converter section 6 is a sampling that is an integral multiple of this sampling frequency Fs = 44.1 kHz with respect to 44.1 kHz as the predetermined sampling frequency derived from the format of the mini-disc 3. Digitized at frequency Fs. The sampling frequency Fs for digitization may be an integer multiple of 44.1 kHz.Reference exampleIn this case, for example, a sampling frequency Fs = 88.2 kHz, which is twice as an integral multiple, is employed.
[0074]
  Therefore, the acoustic signal that is an analog signal input to the analog-digital converter unit 6 is sampled at a sampling frequency Fs = 88.2 kHz and converted into a digital signal, as shown in FIG.
[0075]
  The acoustic signal converted into the digital signal is input to the next signal processing circuit unit 4. The digital signal input to the signal processing circuit unit 4 is compressed to 1/5 by the ATRAC unit 5 in which the sampling frequency Fs is set to 88.1 kHz by the control unit 9.
[0076]
  Since the minidisc system is assumed here, the compression technique used is the ATRAC system. However, the compression technique is not necessarily limited to this. If the system is not limited to the minidisk, other compression techniques are used. Other methods such as MPEG (Moving Picture Experts Group) audio may be used.
[0077]
  Next, compression is performed by the ATRAC unit 5WasThe sound signal data is input to the memory unit 8 and stored therein. When a predetermined amount of the compressed acoustic signal is stored in the memory unit 8, as shown in FIG. 2B, the stored acoustic data is the sampling frequency Fs derived from the normal clock, that is, the format of the mini-disc 3 sequentially. Recording on the mini-disc 3 at 44.1 kHz.
[0078]
  That is, the acoustic signal data sampled at the sampling frequency Fs = 88.2 kHz and stored in the memory unit 8 is extended to the sampling frequency Fs = 44.1 kHz and recorded on the mini-disc 3. For this reason, the data frequency is also halved. Therefore, for example, when a 1 kHz acoustic signal is recorded on the mini-disc 3 by a high sound quality method, it is recorded at 500 Hz.
[0079]
  Like thisReference exampleThe input analog data is digitized at a sampling frequency Fs = 88.2 kHz, compressed, temporarily stored, and recorded on the mini disk 3 at a sampling frequency Fs = 44.1 kHz.
[0080]
  Here, in the conventional method, the input transfer rate is 1.4 Mbps (2 cH × 16 bits × 44.1 kHz), and the transfer rate of the compressed data, that is, the recording speed to the mini disc 3 is about 1/5, which is about 300 kbps. It has become.
[0081]
  But bookReference exampleSince the analog-digital converter unit 6 and the ATRAC unit 5 are operated at twice the speed, the input transfer rate is 2.8 Mbps (2 cH × 16 bits × 88.2 kHz), but the mini-disc 3 of compressed data is used. The recording speed is about 300 kbps, which is the same as in the conventional method, and the frequency of recording on the mini-disc 3 is doubled as compared with the conventional method to record the compressed signal.
[0082]
  Therefore, in the conventional method, recording was performed on the mini disc 3 once every about 2 seconds and about 0.5 seconds.Reference exampleThen, recording is performed on the mini-disc 3 once every about 1 second and about 0.5 second.
[0083]
  Further, since the compression amount is not changed for the data recording area, the actual data amount is doubled and the data recording area is also doubled. This means that since the recording area of the mini-disc 3 is defined, the actual recordable time is halved compared to the conventional recordable time. That is, for example, in the case of the mini-disc 3 capable of recording for 80 minutes, it can be shown that data for 80 minutes can be recorded only for half of that which can be recorded for 40 minutes.
[0084]
  Here, a management method when recording on the mini-disc 3 in such a manner will be described.
[0085]
  In general, in the UTOC (User Table Of Contents) area 3d (see FIG. 4) as a third recording area which is a user data management area in the mini-disc 3, incidental information data of the recorded acoustic data is recorded. It seems to be a bookReference exampleThen, the accompanying information data includes that the main information is data sampled at a sampling frequency Fs = 88.2 kHz which is twice a predetermined sampling frequency Fs = 44.1 kHz.
[0086]
  That is, information that cannot be reproduced by the conventional method is assigned to the incidental information data as information that is separate from the conventional management data. As a result, when the mini-disc 3 created at the above-mentioned double sampling frequency Fs = 88.2 kHz is reproduced by the conventional method, it can be managed not to cause problems such as noise.
[0087]
  Next, at the time of reproduction, information recorded through the pickup unit 1 is obtained from the mini-disc 3 at the same speed as the conventional method, that is, the sampling frequency Fs = 44.1 kHz. Here, the recording information is read out before the main information is read out. First, management data indicating that the data is the mini-disc 3 obtained by digitizing and compressing data from the UTOC information at twice the sampling frequency Fs = 88.2 kHz. Then, this management data is input to the control unit 9. The control unit 9 controls the ATRAC unit 5 and the digital / analog converter unit 7 in the signal processing unit 4 to operate at the sampling frequency Fs = 88.2 kHz based on the obtained management data.
[0088]
  Next, the data obtained from the recorded main information part is stored in the memory part 8 through the signal processing part 4 as the compressed data. When a predetermined amount of the read data is stored in the memory unit 8, the data is taken out from the memory unit 8 in the stored order and input to the signal processing circuit 4.
[0089]
  The data input to the signal processing unit 4 is input to the ATRAC unit 5 that is switched to the decompression operation by the control unit 9. The operation sampling frequency Fs of the ATRAC unit 5 is set to operate at 88.2 kHz based on the management data input to the control unit 9, and is a sampling frequency Fs that is twice the normal sampling frequency.
[0090]
  That is, the compressed acoustic data is expanded by the ATRAC unit 5 and decoded into digital data having a sampling frequency Fs = 88.2 kHz. The digital signal decoded at the sampling frequency Fs = 88.2 kHz is a digital analog whose operation is set at twice the sampling frequency Fs = 88.2 kHz based on the management data of the control unit 9 as in the ATRAC unit 5. Input to the converter unit 7.
[0091]
  As shown in FIG. 2 (c), the data input to the digital-analog converter unit 7 operating at the double sampling frequency Fs = 88.2 kHz is converted into the original wideband analog signal and converted to analog. The signal is output to the output unit 13 as a signal.
[0092]
  As a result, the analog signal can be reproduced up to the frequency = 44.1 kHz, so that the reproduction in the high frequency region is possible and the high sound quality can be obtained as compared with the conventional case.
[0093]
  2A, 2B, and 2C, the transition of the waveform is the same as the waveform recorded on the mini-disc 3 shown in FIG. 2B compared to FIGS. 2A and 2C. This is because the band has been lowered because it was recorded at 44.1 kHz, and as described above, the data amount is twice as much as that of the conventional method. ing.
[0094]
  Further, if the sound signal data sampled at the sampling frequency Fs = 88.2 kHz and recorded in the memory unit 8 is recorded as it is on the mini disc 3 at the sampling frequency Fs = 88.2 kHz, the data recorded on the mini disc 3 is recorded. Although the amount is doubled, when recording on the mini-disc 3, in order to record at the same sampling frequency Fs = 44.1 kHz as in the conventional method, the time axis is doubled, and the recording area is the same as in the conventional method. It takes twice as much.
[0095]
  Like thisReference exampleIn the MD recording / reproducing apparatus 10, a digital information signal obtained by converting an analog information signal and digitized is recorded on the mini disk 3 at a predetermined sampling frequency Fs = 44.1 kHz, which is defined as a recording format of the mini disk 3. Play from disc 3.
[0096]
  Here, when the analog information signal is recorded on the mini-disc 3, first, the analog-digital converter unit 6 performs the analog information signal at the sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency Fs = 44.1 kHz. Is converted into a digital information signal.
[0097]
  That is, when an analog information signal is digitized, it can be converted only up to about a half of the sampling frequency Fs. Conventionally, analog information in a higher frequency region than a frequency of about 20 kHz is considered in consideration of filter characteristics and the like. The signal could not be converted.
[0098]
  But bookReference exampleThen, the analog information signal is converted into a digital signal at a sampling frequency Fs = 88.2 kHz which is twice a predetermined sampling frequency = 44.1 kHz defined by the conventional mini-disc 3. Therefore, when converted to digital at twice the sampling frequency Fs = 88.2 kHz, an analog information signal in a high frequency region up to a half frequency 44.1 kHz can be converted. As a result, it is possible to convert an analog information signal in a high frequency region that is approximately twice as high as that in the prior art.
[0099]
  Next, the digital information signal converted at the sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency is similarly sampled by the ATRAC unit 5 twice the predetermined sampling frequency Fs = 44.1 kHz. Compressed at Fs = 88.2 kHz.
[0100]
  The compressed digital information signal is then recorded on the mini disk 3 by the pickup unit 1 and the magnetic head unit 2 at a sampling frequency Fs = 44.1 kHz, which is a predetermined sampling frequency Fs determined on the mini disk 3. Is done. Therefore, since recording is performed on the mini disc 3 at the sampling frequency Fs = 44.1 kHz, which is a predetermined sampling frequency determined on the mini disc 3, recording can be performed without any problem.
[0101]
  As a result, even when data in a wide band is included, recording can be performed at a predetermined sampling frequency Fs = 44.1 kHz when recording on the mini-disc 3. That is, since the conventional recording technique can be used and recording can be performed up to the high frequency region without providing complicated signal processing means, high quality can be ensured by reducing the number of changing elements in the apparatus.
[0102]
  Therefore, MD recording that can improve the sound quality by reproducing the analog waveform more faithfully while avoiding complicated signal processing while ensuring compatibility with the conventional method in writing to the mini-disc 3. The playback device 10 can be provided.
[0103]
  Also bookReference exampleIn the MD recording / reproducing apparatus 10, the pickup unit 1 that reads a digital information signal from the mini-disc 3 at a predetermined sampling frequency Fs = 44.1 kHz, and the digital information signal read by the pickup unit 1 is converted into the recording format of the mini-disc 3. The ATRAC unit 5 that expands at a sampling frequency Fs = 88.2 kHz which is twice the sampling frequency Fs = 44.1 kHz to be determined, and the digital information signal expanded from the ATRAC unit 5 are converted into the predetermined sampling frequency Fs = 44.1 kHz. And a digital-analog converter section 7 for converting into an analog information signal at a sampling frequency Fs = 88.2 kHz.
[0104]
  That is, when the mini-disc 3 recorded by the high-quality MD recording / reproducing apparatus 10 is reproduced, first, the pickup unit 1 is a sampling frequency determined in the recording format of the mini-disc 3 from the mini-disc 3, for example, sampling frequency Fs = Read the digital information signal at 44.1 kHz. Since this reading is performed at the sampling frequency Fs = 44.1 kHz, which is the predetermined sampling frequency of the mini-disc 3, it can be read without any problem.
[0105]
  Next, the digital information signal read by the pickup unit 1 is expanded by the ATRAC unit 5 at a sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency Fs = 44.1 kHz. Further, the digital information signal expanded by the ATRAC unit 5 is converted by the digital / analog converter unit 7 into an analog information signal at a sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency Fs = 44.1 kHz. Is done.
[0106]
  As a result, the data recorded on the mini-disc 3 at the sampling frequency Fs = 44.1 kHz is read out, expanded at twice the predetermined sampling frequency Fs = 44.1 kHz, and then converted from digital to analog for high-quality sound reproduction. be able to.
[0107]
  As for reproduction, since the data is read from the mini disk 3 at the same frequency as that of the conventional device, it is possible to reduce the number of changes in the device from the conventional device and to reproduce the sound with high sound quality.
[0108]
  Therefore, MD recording that can improve the sound quality by reproducing the analog waveform more faithfully while avoiding complicated signal processing while ensuring compatibility with the conventional method for reading to the mini-disc 3. The playback device 10 can be provided.
[0109]
  By the way, a high-quality sound system for recording on the mini-disc 3 an information signal which is converted into a digital information signal at a sampling frequency Fs = 88.2 kHz which is twice the sampling frequency Fs = 44.1 kHz defined in the recording format of the mini-disc 3 However, when recording on the mini-disc 3, recording is performed at a normal predetermined sampling frequency Fs = 44.1 kHz. For this reason, unless the information recorded in the high sound quality system is recorded in, for example, the UTOC area of the mini-disc 3, it cannot be properly reproduced in the high sound quality system.
[0110]
  But bookReference exampleAccording to the present invention, the mini-disc 3 is a mini-disc 3 on which a digital information signal that has been digitized and compressed at a sampling frequency Fs = 88.2 kHz that is twice the predetermined sampling frequency Fs = 44.1 kHz is recorded. In addition, a control unit 9 for recording additional information separately from the main information is provided.
[0111]
  Therefore, when the reproduction is performed, it can be determined that the recording is performed by the high sound quality method by referring to the additional information. Therefore, the reproduction can be appropriately performed by the high sound quality method.
[0112]
  In addition, this makes it possible to read the contents of the mini-disc 3 without reproducing the main information, and it is possible to control so as not to reproduce in the conventional method.
[0113]
  As a result, while maintaining compatibility with the conventional method for writing to and reading from the mini-disc 3, it avoids complicated signal processing, and reproduces analog waveforms more faithfully to improve sound quality. The MD recording / reproducing apparatus 10 to be obtained can be provided.
[0114]
  Also bookReference exampleIn the MD recording / reproducing apparatus 10, when the additional information is obtained from the mini-disc 3 in which the additional information is recorded by the control unit 9, the control unit 9 doubles the predetermined sampling frequency Fs = 44.1 kHz. The ATRAC unit 5 and the digital / analog converter unit 7 are operated at the sampling frequency Fs = 88.2 kHz.
[0115]
  Therefore, the additional information recorded on the mini-disc 3 can be set to an appropriate sampling frequency without input from the outside what sampling frequency is recorded. In other words, optimal reproduction is possible without determining whether the disc is a mini disc 3 recorded by a conventional method or a mini disc 3 recorded by a high sound quality method. In addition, it is possible to prevent reproduction at a different sampling frequency by mistake.
[0116]
    [Embodiment 1]
  The embodiment of the present invention will be described with reference to FIGS. 3 to 7 as follows. For convenience of explanation, the above-mentionedReference exampleThe members having the same functions as those shown in the drawings are denoted by the same reference numerals, and the description thereof is omitted.
[0117]
  In the MD recording / reproducing apparatus of the present embodiment,Reference exampleAs in the case of the analog-digital converter unit 6, the ATRAC unit 5, and the digital-analog converter unit 7, the sampling frequency Fs = 88.2 which is twice the sampling frequency Fs = 44.1 kHz set for recording on the mini-disc 3. The conversion process and the compression / decompression process are performed at 2 kHz. When recording to the mini-disc 3, the data is divided into two for each sampling data and recorded at the sampling frequency Fs = 44.1 kHz. As a result, both the conventional method and the high sound quality method can be switched and reproduced easily.
[0118]
  That is, in the MD recording / reproducing apparatus 20 as the digital recording / reproducing apparatus of the present embodiment, the memory unit 8 has two areas, an A area 8a and a B area 8b, as shown in FIG. A second low-pass filter (LPF) unit 21 is provided between the signal processing unit 4 and the A region 8 a in the memory unit 8.
[0119]
  Then, the signal compressed at the sampling frequency Fs = 88.2 kHz by the ATRAC unit 5 of the signal processing unit 4 is sequentially stored in the memory unit 8 for every odd term and even term in sampling. Specifically, odd terms in sampling are sequentially stored in the A region 8a of the memory unit 8 via the second low-pass filter unit 21 as a filter, and even terms in sampling are sequentially stored directly in the B region 8b of the memory unit 8. The
[0120]
  In the present embodiment, the second low-pass filter unit 21 is provided before the input of the A region 8a in the memory unit 8. However, the present invention is not limited to this, and the input of the B region 8b in the memory unit 8 is not limited thereto. Even before. In other words, the second low-pass filter unit 21 is inserted before the input of at least one region before being input to the A region 8a or the B region 8b of the memory unit 8.
[0121]
  The second low-pass filter unit 21 is set with a cutoff frequency so as to cut the Nyquist frequency or higher corresponding to the sampling frequency Fs = 44.1 kHz. Here, the cutoff frequency is set to 20 kHz. The reason why the cutoff frequency of the second low-pass filter unit 21 is set to 20 kHz will be described in detail in the explanation at the time of reproduction to be described later.
[0122]
  Next, when the compressed data stored in the A area 8a and B area 8b in the memory unit 8 reaches a predetermined amount, the data stored in the memory unit 8 is alternately called from the A area 8a and B area 8b, and the magnetic head unit 2 is recorded on the mini-disc 3 at a sampling frequency Fs = 44.1 kHz. In the case of recording on the mini disc 3, as in the case of storing in the memory unit 8, the data in the A area 8a and the data in the B area 8b are respectively stored in the main information of the mini disk 3 as shown in FIG. In the recording user area 3c, which is a recording place, the A recording area 3a as the first recording area or the B recording area 3b as the second recording area is recorded separately.
[0123]
  In the case where the odd-numbered and even-numbered data are alternately recorded in time series without dividing the area on the mini-disc 3, and the parts are linked by the link information managed by the UTOC sector. Since the part of the mini-disc 3 is defined as 255 for the entire disc, it will immediately fail.
[0124]
  The UTOC management in the UTOC area 3d of the data in the two areas on the mini-disc 3, that is, the A recording area 3a and the B recording area 3b is the data of either the A recording area 3a or the B recording area 3b, in this case the A recording The odd-numbered data in the area 3a may be managed in the UTOC sector 0 as usual. When the other is managed by the UTOC sector 0, data similar to the data in the A recording area 3a and the data in the B recording area 3b are usually recorded, so that the track number setting, etc. However, there is a problem that the same music is played twice even though they are strictly different. Therefore, the UTOC management of the data in the B recording area 3b in the mini-disc 3 uses the UTOC sector 5 and later which are not checked by the conventional method. In this embodiment, the UTOC sector 5 is used for even-numbered data management.
[0125]
  Table 1 shows an example in which music management data of odd-numbered sampling data is recorded in UTOC sector 0 and music management data of even-numbered sampling data is recorded in UTOC sector 5.
[0126]
[Table 1]

[0127]
  Here, “TNO.” Is a track number. In addition, TNO. 1 and TNO. 3 shows a song recorded by a high-quality sound system. 1 and TNO. 3 odd-numbered sampling data is managed in the UTOC sector 0.
[0128]
  TNO. The start address of the odd-numbered sampling data 1 is “a0” and the end address is “b0”.
[0129]
  In addition, TNO. The even-numbered sampling data of 1 is managed in the UTOC sector 5. The TNO. The start address of even-numbered sampling data 1 is “a5” and the end address is “b5”.
[0130]
  In addition, TNO. The odd number 3 sampling data has a start address “e0” and an end address “f0”.
[0131]
  Furthermore, TNO. The even-numbered sampling data 3 is managed in the UTOC sector 5. The TNO. The start address of the even-numbered sampling data 3 is “e5” and the end address is “f5”.
[0132]
  TNO. No. 2 has no data managed in the UTOC sector 5 and is a normally recorded song, that is, a song recorded by the conventional method, and is managed only by the UTOC sector 0. TNO. The start address in the second disk is “c0”, and the end address is “d0”.
[0133]
  As described above, by managing odd-numbered sampling data and even-numbered sampling data in the UTOC sector, UTOC sector 0 is confirmed for reproduction in the conventional system, so there is data here. For example, data recorded by normal sampling and data obtained by sampling at twice the sampling frequency Fs = 88.2 kHz can be reproduced. That is, regardless of which method is used for recording, when the conventional method is used for reproduction, the UTOC sector 5 is ignored and data in the even-numbered area is not reproduced.
[0134]
  Therefore, the mini-disc 3 recorded by the high sound quality system can be compatible with the conventional system. However, in the case of the mini-disc 3 which has obtained data at twice the sampling frequency Fs = 88.2 kHz, the recordable time for the even area is substantially shortened.
[0135]
  Further, in such a method of recording in the A recording area 3a or B recording area 3b of the mini-disc 3 alternately for every odd term and even term in sampling, as shown in FIG. 5A, the sampling frequency Fs = 88. After the analog information signal is digitally converted and compressed at 2 kHz, the A recording area 3a or B recording area 3b of the mini-disc 3 has a sampling frequency Fs as shown in FIGS. = 44.1 kHz.
[0136]
  Further, when the mini-disc 3 recorded in this way is reproduced, as shown in FIG. 5D, it is expanded at the sampling frequency Fs = 88.2 kHz and converted into an analog information signal.
[0137]
  A reproducing operation in the MD recording / reproducing apparatus 20 having the above-described configuration will be described with reference to flowcharts shown in FIGS.
[0138]
  First, when reading the UTOC information recorded on the mini-disc 3, as shown in FIG. 6, the pickup unit 1 first reads out the UTOC sector 0 from the UTOC area of the recorded mini-disc 3 (S1). .
[0139]
  Next, it is determined whether the UTOC sector 5 is used (S2). If the UTOC sector 5 is used in S2, the UTOC sector 5 is read (S3).
[0140]
  On the other hand, if the UTOC sector 5 is not used, nothing is done in the UTOC read, and the process exits the UTOC read flow.
[0141]
  Next, after reading out the UTOC sector 5 in S3, the station number, start address and end address of the song recorded by the high sound quality system are stored in the memory unit 8 (S4).
[0142]
  The above UTOC reading procedure is performed by controlling the signal processing unit 4 by the control unit 9 as the distribution information recording means.
[0143]
  Next, when the mini-disc 3 is reproduced, as shown in FIG. 7, first, whether or not high-quality sound reproduction is performed is input from the key input unit 14 (S11).
[0144]
  Next, when reproducing the high sound quality, it is determined from the data stored in the memory unit 8 whether or not the recorded mini-disc 3 is a song recorded with high sound quality (S12).
[0145]
  That is, data is recorded in the UTOC sector 5 when high sound quality recording is performed, and data is not recorded in the UTOC sector 5 when high sound quality recording is not performed. Therefore, whether or not high-quality sound recording is performed can be determined based on whether or not data is recorded in the UTOC sector 5.
[0146]
  If normal playback is designated in the key input in S11, the process proceeds to S17, which will be described later, in S12, because it is not a song recorded with high sound quality.
[0147]
  In this flowchart, whether or not high sound quality reproduction is performed is input from the key input unit 14 in S11. However, the present invention is not limited to this. For example, high sound quality reproduction is always prioritized and high sound quality recording is performed. If the mini-disc 3 only plays back high-quality sound, S11 may be omitted and the process may start from S12.
[0148]
  Next, the sampling frequency Fs in the ATRAC unit 5 that performs the expansion process in the signal processing unit 4 and the digital / analog converter unit 7 is set according to the determination result of whether or not the song has been recorded with high sound quality in S12. That is, the sampling frequency Fs is set to 88.2 kHz for a song recorded with high sound quality (S13), and the sampling frequency Fs is set to 44.1 kHz for normal recording (S17). This is performed by the control unit 9 as filter data reproduction control means and data connection control means.
[0149]
  Next, in the case of a song recorded with high sound quality, odd-numbered data and even-numbered data are alternately read for each fixed block and stored in the A area 8a and the B recording area 3b of the memory unit 8 (S14). Note that the capacity of a certain block is determined by the capacity of the memory unit 8 to be used.
[0150]
  Next, the odd-numbered data that is the sampling data of the UTOC sector 0 and the even-numbered data that is the sampling data of the UTOC sector 5 are rearranged in the original order by the signal processing unit 4 as data connection control means. (S15).
[0151]
  Next, the data rearranged in the original order is input to the ATRAC unit 5 of the signal processing unit 4 and decompressed data is compressed. The operation of the ATRAC unit 5 here is performed at the set sampling frequency Fs = 88.2 kHz.
[0152]
  The digital data expanded by the ATRAC unit 5 operating at the sampling frequency Fs = 88.2 kHz is converted into the digital analog converter operating at the set sampling frequency Fs = 88.2 kHz, similarly to the ATRAC unit 5. Input to part 7.
[0153]
  The digital data input to the digital-analog converter unit 7 is converted into an analog signal here, and high-quality sound reproduction is started (S16).
[0154]
  On the other hand, if it is determined in S12 that the song is not recorded with high sound quality, the sampling frequency Fs is set to 44.1 kHz in S17 as described above, then the sampling data managed by UTOC sector 0 is read, and the memory unit 8 Is accumulated in the A area 8a (S18).
[0155]
  When a certain amount of data is accumulated, the process proceeds to S16, where the data stored in the memory unit 8 is read again and input to the signal processing unit 4. The signal processing unit 4 performs an expansion process in the ATRAC unit 5 set to the sampling frequency Fs = 44.1 kHz. The expanded data is converted into an audio analog signal by the digital / analog converter unit 7 set to the sampling frequency Fs = 44.1 kHz, and the reproduction of the sound is started.
[0156]
  In the case of normal reproduction, the reproduction frequency is 20 kHz because the sampling frequency Fs = 44.1 kHz.
[0157]
  Here, the meaning of having passed through the second low-pass filter unit 21 when the odd-numbered data in the sampling is put in the A region 8a of the memory unit 8 described above.
[0158]
  That is, if the second low-pass filter unit 21 is not provided, it is not possible to suppress the occurrence of aliasing noise caused by setting the sampling frequency Fs to 44.1 kHz. Like the conventional method, the odd-numbered data in the sampling is passed through the second low-pass filter unit 21 before being stored so that the data can be reproduced at the sampling frequency Fs = 44.1 kHz. This is recorded on the assumption that the odd-numbered data recorded in the A recording area 3a of the mini-disc 3 does not contain a component having a frequency of 20 kHz or more.
[0159]
  By adopting this method, it is possible to reproduce by the conventional method, and even the mini disc 3 recorded for reproduction of the high sound quality method can be reproduced although the reproduction time is shortened.
[0160]
  As described above, in the MD recording / reproducing apparatus 20 of the present embodiment, the pickup unit 1 and the magnetic head unit 2 are sampled twice the sampling frequency Fs = 44.1 kHz determined by the ATRAC unit 5 in the recording format of the minidisk 3. The digital information signal compressed at the frequency Fs = 88.2 kHz is divided and recorded on the A recording area 3a and the B recording area 3b of the mini-disc 3 alternately every sampling.
[0161]
  For this reason, each grouped data can be distributed to two A recording areas 3a and B recording areas 3b. As a result, the data recorded in the A recording area 3a and the B recording area 3b can be read separately, and reading from the mini-disc 3 is simplified. Therefore, data management can be simplified. Also, for data read access, the access time can be shortened because the data recording area is limited.
[0162]
  By the way, when the main information is divided and recorded in the A recording area 3a and the B recording area 3b in the mini disc 3, it is preferable to record the additional information of the management data in a place where it can be read out immediately.
[0163]
  In contrast, in the present embodiment,The control unit 9Additional information for managing the digital information signal recorded in the A recording area 3a or B recording area 3b of the mini disk 3 is recorded in the UTOC area 3d of the mini disk 3.
[0164]
  Therefore, by recording the additional information of the management data in a location different from the recording user area 3c for recording the main information, the information recorded on the mini-disc 3 can be obtained quickly by simplifying the distinction between the information and the management data. And the processing time can be shortened.
[0165]
  Further, in the MD recording / reproducing apparatus 20 of the present embodiment, at least one of the A information among the digital information signals stored in the mini-disc 3 by being alternately allocated to the A recording area 3a and the B recording area 3b for each sampling. The recording area 3 a is data that has passed through the second low-pass filter unit 21.
[0166]
  For this reason, at least one of the frequency bands can be set to the same frequency band as when recording at the sampling frequency Fs = 44.1 kHz defined in the recording format of the mini-disc 3, so that the same level of data is recorded in two places. In addition, the usage of the mini-disc 3 is expanded.
[0167]
  Furthermore, on the contrary, since the other can include data having a Nyquist frequency (20 kHz) or higher, reproduction by a high sound quality system is also possible.
[0168]
  Further, in the MD recording / reproducing apparatus 20 of the present embodiment, the control unit 9 reproduces only the data via the second low-pass filter unit 21 when reproducing at the predetermined sampling frequency Fs = 44.1 kHz. .
[0169]
  Therefore, a signal sampled at a sampling frequency Fs = 88.2 kHz that is twice the sampling frequency Fs = 44.1 kHz can be reproduced at the sampling frequency Fs = 44.1 kHz. In other words, this means that a mini-disc 3 recorded at a sampling frequency Fs = 88.2 kHz which is twice the sampling frequency Fs = 44.1 kHz can be reproduced on a conventional machine. The compatibility of the disk 3 can be reliably maintained. However, the reproduction time is shorter than the time recorded on the mini disc 3 by the conventional method.
[0170]
  In the MD recording / reproducing apparatus 20 of the present embodiment, the digital information signal is digitized and compressed at a sampling frequency Fs = 88.2 kHz which is twice the sampling frequency Fs = 44.1 kHz defined in the recording format of the mini-disc 3. Is reproduced at a sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency Fs = 44.1 kHz, the control unit 9 causes the data in the A recording area 3a of the minidisc 3 to be reproduced. And the data in the B recording area 3b are rearranged in the original order, and the ATRAC section 5 and the digital / analog converter section 7 are operated at a sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency Fs = 44.1 kHz. .
[0171]
  For this reason, when reproducing the mini-disc 3 recorded at the sampling frequency Fs = 88.2 kHz which is twice the predetermined sampling frequency Fs = 44.1 kHz, it is only necessary to perform the reproducing operation in the reverse procedure of the recorded method. High sound quality playback is possible.
[0172]
【The invention's effect】
  As described above, the digital recording / reproducing apparatus of the present invention is digitized by the digitizing means for converting an analog information signal into a digital information signal at a sampling frequency that is an integral multiple of a predetermined sampling frequency, and by the digitizing means. Compression means for compressing the digital information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency, and the digital information signal compressed by the compression means., And assign them alternately to the first recording area and the second recording area of the recording medium in turn for each sampling.Recording means for recording at the predetermined sampling frequency.
[0173]
  Therefore, the analog information signal is converted to digital at a sampling frequency that is an integral multiple of a predetermined sampling frequency defined by the conventional recording medium. It is possible to convert analog information signals in a high frequency range up to an integer multiple of frequency. As a result, it is possible to convert an analog information signal in a high-frequency region that is approximately an integral multiple of that in the prior art.
[0174]
  Even in a state where broadband data is included, recording can be performed at a predetermined sampling frequency when recording on a recording medium. That is, since the conventional recording technique can be used and recording can be performed up to the high frequency region without providing complicated signal processing means, high quality can be ensured by reducing the number of changing elements in the apparatus.
[0175]
  Therefore, digital recording and playback that can improve the sound quality by reproducing analog waveforms more faithfully while avoiding complicated signal processing while ensuring compatibility with conventional methods for writing to recording media There exists an effect that an apparatus can be provided.
[0176]
  The recording means also converts the digital information signal compressed by the compression means at a sampling frequency that is an integral multiple of a predetermined sampling frequency to the first recording area and the second recording area of the recording medium alternately every sampling. Sort and record.
[0177]
Therefore, each grouped data can be divided into two first recording areas and second recording areas. As a result, data recorded in the first recording area and the second recording area can be read separately, and reading from the recording medium is simplified. Therefore, data management can be simplified. In addition, data read access is also limited because the data recording area is limited, so that the access time can be shortened.
[0178]
  As described above, the digital recording / reproducing apparatus of the present invention is the above-described digital recording / reproducing apparatus, wherein the reading means reads the digital information signal from the recording medium at a predetermined sampling frequency, and the digital information signal read by the reading means. Is expanded at a sampling frequency that is an integral multiple of the predetermined sampling frequency, and the digital information signal expanded by the expansion means is converted into an analog information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency. And analogizing means.
[0179]
  SoThisTherefore, data recorded on a recording medium at a predetermined sampling frequency can be read out and expanded at an integral multiple of the predetermined sampling frequency, and then digital-to-analog conversion can be performed for high sound quality reproduction.
[0180]
  As for reproduction, since the data is read from the recording medium at the same frequency as that of the conventional device, it is possible to reduce the number of changes in the device from the conventional device and to reproduce the sound with high sound quality.
[0181]
  Therefore, digital recording and playback that can improve the sound quality by reproducing analog waveforms more faithfully while avoiding complicated signal processing while ensuring compatibility with conventional methods for reading to recording media There exists an effect that an apparatus can be provided.
[0182]
  As described above, the digital recording / reproducing apparatus of the present invention is a recording medium on which a digital information signal digitized and compressed at a sampling frequency that is an integral multiple of a predetermined sampling frequency in the above-described digital recording / reproducing apparatus is recorded. In other words, the recording medium is provided with sampling information recording means for recording as additional information separately from the main information.
[0183]
  Therefore, when the reproduction is performed, it can be determined that the recording is performed by the high sound quality method by referring to the additional information, and therefore, the reproduction can be appropriately performed by the high sound quality method.
[0184]
  In addition, this makes it possible to read the content of the recording medium without reproducing the main information, and control so as not to reproduce in the conventional method.
[0185]
  As a result, it is possible to improve the sound quality by reproducing the analog waveform more faithfully while avoiding complicated signal processing and the like while ensuring compatibility with the conventional method for writing to and reading from the recording medium. There is an effect that a digital recording / reproducing apparatus can be provided.
[0186]
  As described above, when the additional information is obtained from the recording medium on which the additional information is recorded by the sampling information recording means in the digital recording / reproducing apparatus described above, the digital recording / reproducing apparatus of the present invention has a predetermined sampling frequency. Additional information operation control means for operating the decompression means and the analogization means at a sampling frequency that is an integer multiple of.
[0187]
  Therefore, it is possible to set an appropriate sampling frequency without input from the outside what kind of sampling frequency is recorded by the additional information recorded on the recording medium. In other words, optimum reproduction is possible without manually determining whether the recording medium is recorded by the conventional method or the recording medium recorded by the high sound quality method. In addition, there is an effect that it is possible to prevent reproduction at a different sampling frequency by mistake.
[0188]
  As described above, the digital recording / reproducing apparatus of the present invention has the additional information for managing the digital information signal recorded in the first recording area or the second recording area of the recording medium in the above-described digital recording / reproducing apparatus. Distribution information recording means for recording in a third recording area such as UTOC of the recording medium is provided.
[0189]
  Therefore, by recording the additional information of the management data in a location different from the location where the main information is recorded, the information recorded on the recording medium can be obtained quickly by simplifying the distinction between the information and the management data, and the processing time There is an effect that can be shortened.
[0190]
  As described above, the digital recording / reproducing apparatus of the present invention is stored in the recording medium in the above-described digital recording / reproducing apparatus in such a manner that the first recording area and the second recording area are alternately allocated to the recording medium sequentially for each sampling. At least one of the digital information signals is data that has passed through a filter.
[0191]
  Therefore, at least one of them can have the same frequency band as when recording at a predetermined sampling frequency, so that the same level of data is not recorded in two places, and the method of using the recording medium is expanded. The
[0192]
  On the other hand, since the other can include data of the Nyquist frequency or higher, there is an effect that reproduction by a high sound quality system is also possible.
[0193]
  As described above, the digital recording / reproducing apparatus of the present invention is provided with the filter data reproduction control means for reproducing only the data through the filter when reproducing at a predetermined sampling frequency in the digital recording / reproducing apparatus described above. It is what has been.
[0194]
  Therefore, a signal sampled at a sampling frequency that is an integral multiple of the predetermined sampling frequency can be reproduced at the predetermined sampling frequency. In other words, this means that a recording medium recorded at a sampling frequency that is an integral multiple of a predetermined sampling frequency can be reproduced on a conventional machine, and thereby compatibility in writing to and reading from the recording medium. There is an effect that can be reliably maintained.
[0195]
  As described above, the digital recording / reproducing apparatus of the present invention is a recording medium that records a digital information signal that has been digitized and compressed at a sampling frequency that is an integral multiple of a predetermined sampling frequency in the digital recording / reproducing apparatus described above. When reproducing at a sampling frequency that is an integral multiple of the predetermined sampling frequency, the data of the first recording area and the data of the second recording area on the recording medium are rearranged in the original order, and an integer of the predetermined sampling frequency A data connection control means for operating the decompression means and the analogization means at a double sampling frequency is provided.
[0196]
  Therefore, when playing back a recording medium recorded at a sampling frequency that is an integral multiple of the predetermined sampling frequency, it is possible to achieve high-quality sound playback only by performing a playback operation in the reverse procedure of the recorded method. Play.
[Brief description of the drawings]
FIG. 1 shows the present invention.Reference examples on which to baseFIG.
[Figure 2]Reference exampleIt is a conceptual waveform diagram which shows the signal in each position in the circuit block of (a), and (a) operates by sampling an information signal with a sampling frequency Fs = 88.2 kHz.DiA conceptual waveform in an analog-digital converter unit for digitization and an ATRAC unit for compression, (b) shows a conceptual waveform recorded on a mini-disc at a sampling frequency Fs = 44.1 kHz, (c) 2 shows conceptual waveforms in an ATRAC section that operates and expands an information signal at a sampling frequency Fs = 88.2 kHz and a digital analog converter section that performs analog conversion.
FIG. 3 shows an MD recording / reproducing apparatus according to the present invention.EmbodimentFIG.
FIG. 4 is a plan view showing the structure of a mini-disc which is recorded by sorting the odd and even terms of sampling by the MD recording / reproducing apparatus.
FIG. 5 is a conceptual waveform diagram showing a signal at each position in a circuit block of the MD recording / reproducing apparatus. FIG. 5A shows an information signal operated by sampling at a sampling frequency Fs = 88.2 kHz.DiThe conceptual waveform in the analog-digital converter part which digitizes and the ATRAC part which performs compression is shown, (b) is the concept of odd-numbered sampling recorded at the sampling frequency Fs = 44.1 kHz in the A recording area of the mini-disc. (C) shows the waveform of the even-numbered sampling recorded at the sampling frequency Fs = 44.1 kHz in the B recording area of the mini-disc, and (d) shows the odd-numbered and even-numbered waveforms. ATRAC performs expansion by operating the combined information signal at a sampling frequency Fs = 88.2 kHz.
2 shows conceptual waveforms in a digital analog converter unit for analog and analog conversion.
FIG. 6 is a flowchart showing an operation when reading a mini-disc recorded by a high sound quality method in the MD recording / reproducing apparatus.
FIG. 7 is a flowchart showing an operation when a mini-disc recorded by a high sound quality method is read out and reproduced by the MD recording / reproducing apparatus.
FIGS. 8A and 8B are explanatory diagrams showing a digital processing procedure of an analog acoustic signal waveform.
FIG. 9 is a block diagram showing a conventional MD recording / reproducing apparatus.
FIG. 10 is a conceptual waveform diagram showing a signal at each position in the circuit block of the MD recording / reproducing apparatus. FIG. 10A shows an information signal operated by sampling at a sampling frequency Fs = 44.1 kHz.Di(B) shows a conceptual waveform recorded at a sampling frequency Fs = 44.1 kHz in the same manner as in the mini-disc, (b) shows a conceptual waveform in an analog / digital converter part for digitization and an ATRAC part for compression, (c ) Shows conceptual waveforms in the ATRAC section that operates the information signal at the sampling frequency Fs = 44.1 kHz and decompresses it, and in the digital-analog converter section that performs analog conversion.
[Explanation of symbols]
  1 Pickup unit (recording means, reading means)
  2 Magnetic head (recording means)
  3 Mini-disc (recording medium)
  3a A recording area (first recording area)
  3b B recording area (second recording area)
  3c Recording user area (where main information is recorded)
  3d UTOC area (third recording area)
  4 Signal processor (data connection control means)
  5 ATRAC section (compression means, expansion means)
  6 Analog-digital converter [ADC] section (digitization means)
  7 Digital-analog converter [DAC] section (analogization means)
  8 Memory part
  8a A area
  8b B area
  9 Control unit (sampling information recording means, additional information operation control means,
                        Distribution information recording means, filter data reproduction control means
                        , Data connection control means)
10 MD recording / reproducing device
20 MD recording / reproducing apparatus
21 Second low-pass filter section (filter)

Claims (8)

In a digital recording / reproducing apparatus that records or reproduces a digital information signal obtained by converting an analog information signal into a digital signal at a predetermined sampling frequency determined on the recording medium.
Digitizing means for converting an analog information signal into a digital information signal at a sampling frequency which is an integral multiple of the predetermined sampling frequency;
Compression means for compressing the digital information signal digitized by the digitizing means at a sampling frequency that is an integral multiple of the predetermined sampling frequency;
Recording means for allocating the digital information signal compressed by the compression means to the first recording area and the second recording area of the recording medium in turn alternately for each sampling and recording at the predetermined sampling frequency; A digital recording / reproducing apparatus comprising: Reading means for reading a digital information signal from a recording medium at a predetermined sampling frequency;
Decompression means for decompressing the digital information signal read by the reading means at a sampling frequency that is an integral multiple of the predetermined sampling frequency;
2. An analog means for converting the digital information signal expanded by the expansion means into an analog information signal at a sampling frequency that is an integral multiple of the predetermined sampling frequency. Digital recording / reproducing device.   Sampling information recording means for recording as additional information separately from the main information on the recording medium that the digital information signal is digitized and compressed at a sampling frequency that is an integral multiple of a predetermined sampling frequency. The digital recording / reproducing apparatus according to claim 1, wherein the digital recording / reproducing apparatus is provided.   When the additional information is obtained from the recording medium on which the additional information is recorded by the sampling information recording means, the additional information operation control means for operating the decompression means and the analog means at a sampling frequency that is an integral multiple of a predetermined sampling frequency. 4. The digital recording / reproducing apparatus according to claim 3, wherein the digital recording / reproducing apparatus is provided. Distributing information recording means for recording additional information for managing the digital information signal recorded in the first recording area or the second recording area in the recording medium in the third recording area of the recording medium is provided. The digital recording / reproducing apparatus according to claim 1. The digital information signal stored in the recording medium alternately and alternately allocated to the first recording area and the second recording area for each sampling is at least one of the data through a filter. 5. The digital recording / reproducing apparatus according to 5. 7. A digital recording / reproducing apparatus according to claim 6, further comprising filter data reproduction control means for reproducing only data that has passed through a filter when reproducing at a predetermined sampling frequency. When a recording medium on which a digital information signal digitized and compressed at a sampling frequency that is an integral multiple of the predetermined sampling frequency is reproduced at a sampling frequency that is an integral multiple of the predetermined sampling frequency, The data in the recording area and the data in the second recording area are rearranged in the original order, and an integer multiple of the predetermined sampling frequency 7. A digital recording / reproducing apparatus according to claim 6, further comprising data connection control means for operating the decompression means and the analogization means at a sampling frequency.

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