JP2004241077A

JP2004241077A - Laser drive circuit and method, and optical disk device

Info

Publication number: JP2004241077A
Application number: JP2003031163A
Authority: JP
Inventors: Takashi Hoshino; 隆司星野
Original assignee: Hitachi LG Data Storage Inc
Current assignee: Hitachi LG Data Storage Inc
Priority date: 2003-02-07
Filing date: 2003-02-07
Publication date: 2004-08-26

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of reducing noise in recording operation, in an optical disk device. <P>SOLUTION: A recording clock and recording data are supplied to a prescribed circuit located inside an optical pickup in a state of mutual time sharing, to generate a recording light-emitting waveform for driving laser diode light emission, and then in a period during which the recording clock is absent, a laser diode is made to emit light, to carry out recording to an optical disk. The timing for the time sharing is decided by a control signal for recording timing generated, based on the recording clock. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、記録媒体としての光ディスクにレーザー光を照射しデータ情報の記録を行う技術に関する。
【０００２】
【従来の技術】
本発明の記録技術に関連する記録回路の従来例を図１０に示す。図１０において、１ｃは信号処理回路、２’はレーザーダイオードを発光駆動するためのダイオード駆動回路、３は、記録動作の基準となる記録クロックの生成を行う記録クロック生成回路、４は、記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成して出力する記録タイミング信号生成回路、５は、同じく記録クロックに基づき記録データを変調して出力する記録データ変調回路、７ａは、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する位相同期発振器（ＰＬＬ）、８はＰＬＬを構成する位相比較器、９は同じく低域通過フィルタ（ＬＰＦ）、１０は同じく周波数電圧制御発振器（ＶＣＯ）、１１は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と上記記録データと上記発光クロックとに基づき、レーザーダイオードを発光させる記録波形を生成する記録発光波形生成回路、１２はレーザーダイオードである。上記構成において、記録クロックは記録クロック生成回路３から位相同期発振器（ＰＬＬ）７ａに入力され、記録データは記録データ変調回路５から記録発光波形生成回路１１に入力される。記録クロックと記録データはそれぞれ互いに別々の信号線により光ピックアップ内の位相同期発振器（ＰＬＬ）７ａと記録発光波形生成回路１１に供給される。位相同期発振器（ＰＬＬ）７ａでは、入力された記録クロックに基づき発光クロックを生成する。記録発光波形生成回路１１には、上記記録データの他、上記記録タイミング信号生成回路４からの記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、上記位相同期発振器（ＰＬＬ）７ａからの上記発光クロックとが入力される。該記録発光波形生成回路１１では、入力された記録データと記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と発光クロックとに基づき、レーザーダイオードを発光させるための記録波形を生成し、レーザーダイオード１２を駆動する。
【０００３】
本発明に関連する従来技術が記載された特許文献としては例えば、特開平１１−２８３２４９号公報（特許文献１）、特開平１１−２１９５２４号公報（特許文献２）及び特開２００１−４３５３１号公報（特許文献３）がある。特開平１１−２８３２４９号公報には、光ディスク装置においてスイッチングタイミングのずれやエラーレートの低下を防ぐために、レーザー駆動集積回路に、レーザーダイオードを駆動する駆動波形情報を記憶する記憶手段を設け、該記憶手段の記憶情報に基づき駆動波形を復元するとともに、ディスクに記録する信号を基に上記記憶手段の駆動波形情報を選択するようにした構成が記載されている。特開平１１−２１９５２４号公報には、光ディスク装置においてスイッチングタイミングのずれやエラーレートの低下を防ぐために、電流の切り替え制御信号を、コード信号に変更して伝送する構成が記載されている。特開２００１−４３５３１号公報には、記録再生装置において、データの記録または再生動作を安定して行う記録ストラテジ制御可能なレーザードライバを半導体レーザーに近接させて設けた構成が記載されている。これら各公報記載の構成においては、データとクロックとは別個の伝送路により伝送される。
【０００４】
【特許文献１】
特開平１１−２８３２４９号公報
【特許文献２】
特開平１１−２１９５２４号公報
【特許文献３】
特開２００１−４３５３１号公報
【０００５】
【発明が解決しようとする課題】
上記図１０の従来技術においては、記録動作中も常時、高周波の記録クロックが光ピックアップ側に供給され、しかも、記録クロック生成回路と光ピックアップ内の回路とが長い接続線で接続される。このため、記録クロックによるノイズが他の回路（サーボ回路、ＡＴＩＰ検出回路等）に妨害を与え、記録の安定性を低下させるおそれがある。また、上記各公報記載の技術においても、記録動作中に常時、高周波の記録クロックが光ピックアップ側に供給されるため、これに基づく妨害が記録の安定性を損なうおそれがある。
本発明の課題点は、上記従来技術の状況に鑑み、光ディスク装置におけるレーザーダイオード駆動において、記録クロックによるノイズの影響を低減し、安定した記録動作を可能にすることである。
本発明の目的は、かかる課題点を解決できる技術の提供にある。
【０００６】
【課題を解決するための手段】
上記課題点を解決するために、本発明では、レーザーダイオードを駆動して光ディスクにデータを記録可能なレーザー駆動回路として、基本的に、記録クロックと記録データを互いに時分割で光ピックアップ内の所定の回路に供給してレーザーダイオード発光駆動用の記録発光波形を生成し、記録クロックのない期間にレーザーダイオードを発光させ光ディスクへの記録を行うようにする。時分割のタイミングは、記録クロックに基づき生成される記録タイミング用制御信号により決める。具体的には、（１）レーザー駆動回路（該当実施例：符号１ａ、１ｂ、２ａ、２ｂ、２ｃ、２ｄ、２ｅ）として、記録データの生成と、記録動作の基準となる記録クロックの生成と、該記録クロックに基づき記録タイミング用制御信号の生成とを行う第１の手段（該当実施例：符号３、４、５）と、少なくとも上記記録クロックに基づき、上記レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２の手段（該当実施例：符号７ａ、７ｂ、７ｃ、７ｄ、７ｅ）と、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成する第３の手段（該当実施例：符号１１）と、上記第３の手段への上記記録データの供給タイミングと、上記第２の手段への上記記録クロックの供給タイミングを、上記第１の手段の上記記録タイミング用制御信号に基づき時分割で切換える第４の手段（該当実施例：符号６）とを備え、記録時、上記記録クロックと上記記録データを時分割で上記第１の手段から、それぞれ上記第２の手段と上記第３の手段に供給する構成とする。（２）レーザー駆動回路（該当実施例：符号１ａ、１ｂ、２ａ、２ｂ、２ｃ、２ｄ、２ｅ）として、記録データを生成する記録データ生成手段（該当実施例：符号５）と、記録動作の基準となる記録クロックを生成する第１のクロック生成手段（該当実施例：符号３）と、上記記録クロックに基づき記録タイミング用制御信号を生成する制御信号生成手段（該当実施例：符号４）と、少なくとも上記記録クロックに基づき、上記レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段（該当実施例：符号７ａ、７ｂ、７ｃ、７ｄ、７ｅ）と、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成する波形生成手段（該当実施例：符号１１）と、上記波形生成手段への上記記録データの供給タイミングと、上記第２のクロック生成手段への上記記録クロックの供給タイミングを、上記記録タイミング用制御信号に基づき時分割で切換える切換え手段（該当実施例：符号６）とを備え、記録時、上記記録クロックと上記記録データを同一の信号線により時分割で、それぞれ上記第２のクロック生成手段と上記波形生成手段とに供給可能とした構成とする。（３）レーザー駆動回路（該当実施例：符号１ｂ、２ｅ）として、記録データを生成する記録データ生成手段（該当実施例：符号５）と、記録動作の基準となる記録クロックを生成する第１のクロック生成手段（該当実施例：符号３）と、上記生成された記録クロックを分周する第１の分周手段（該当実施例：符号２２）と、上記記録クロックに基づき記録タイミング用制御信号を生成する制御信号生成手段（該当実施例：符号４）と、周波数可変型発振手段と該発振手段の出力を分周する第２の分周手段（該当実施例：符号２１）を有し、該発振手段の分周された出力と上記分周された記録クロック、及び、該発振手段の分周された出力と上記記録データに基づき、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段（該当実施例：符号７ｅ）と、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成する波形生成手段（該当実施例：符号１１）と、上記波形生成手段への上記記録データの供給タイミングと上記第２のクロック生成手段への上記分周された記録クロックの供給タイミングを、上記記録タイミング用制御信号に基づき時分割で切換える切換え手段（該当実施例：符号６）とを備え、記録時、上記分周された記録クロックと上記記録データを同一の信号線により時分割で、それぞれ上記第２のクロック生成手段と上記波形生成手段とに供給し、該第２のクロック生成手段では、上記分周された記録クロックの入力期間では、該分周された記録クロックと上記発振手段の分周された出力との周波数誤差信号を選択して加算し、記録データの入力期間では、該記録データと上記発振手段の分周された出力との位相誤差信号を選択して加算し、上記記録クロックに同期した発光クロックを生成する構成とする。また、（４）レーザーにより光ディスクに対しデータを記録可能な構成を備えた光ディスク装置として、記録データと、記録動作の基準となる記録クロックと、該記録クロックに基づき記録タイミング用制御信号とを生成する第１の手段（該当実施例：符号３、４、５）と、少なくとも上記記録クロックに基づき、上記レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２の手段（該当実施例：符号７ａ、７ｂ、７ｃ、７ｄ、７ｅ）と、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成する第３の手段（該当実施例：符号１１）と、上記第３の手段への上記記録データの供給タイミングと、上記第２の手段への上記記録クロックの供給タイミングを、上記第１の手段の上記記録タイミング用制御信号に基づき時分割で切換える第４の手段（該当実施例：符号６）とを備え、記録時、上記記録クロックと上記記録データを時分割で上記第１の手段から、それぞれ上記第２の手段と上記第３の手段に供給するレーザー駆動回路（該当実施例：符号１ａ、１ｂ、２ａ、２ｂ、２ｃ、２ｄ、２ｅ）と、上記レーザー駆動回路により駆動されるレーザーダイオード（該当実施例：符号１２）と、対物レンズを備え上記レーザーダイオードからのレーザー光を光ディスクの記録面に照射する光学系と、少なくとも上記レーザーダイオードと上記光学系を含んで成るピックアップを移動させるピックアップ移動機構と、光ディスクを回転させるスピンドルモータと、該スピンドルモータを駆動するモータ駆動回路とを備えた構成とする。（５）光ディスク装置として、記録データを生成する記録データ生成手段（該当実施例：符号５）と、記録動作の基準となる記録クロックを生成する第１のクロック生成手段（該当実施例：符号３）と、上記記録クロックに基づき記録タイミング用制御信号を生成する制御信号生成手段（該当実施例：符号４）と、少なくとも上記記録クロックに基づき、上記レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段（該当実施例：符号７ａ、７ｂ、７ｃ、７ｄ、７ｅ）と、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成する波形生成手段（該当実施例：符号１１）と、上記波形生成手段への上記記録データの供給タイミングと、上記第２のクロック生成手段への上記記録クロックの供給タイミングを、上記記録タイミング用制御信号に基づき時分割で切換える切換え手段（該当実施例：符号６）とを備え、記録時、上記記録クロックと上記記録データを同一の信号線により時分割で、それぞれ上記第２のクロック生成手段と上記波形生成手段とに供給可能としたレーザー駆動回路（該当実施例：符号１ａ、１ｂ、２ａ、２ｂ、２ｃ、２ｄ、２ｅ）と、上記レーザー駆動回路により駆動されるレーザーダイオード（該当実施例：符号１２）と、対物レンズを備え上記レーザーダイオードからのレーザー光を光ディスクの記録面に照射する光学系と、少なくとも上記レーザーダイオードと上記光学系を含んで成るピックアップを移動させるピックアップ移動機構と、光ディスクを回転させるスピンドルモータと、該スピンドルモータを駆動するモータ駆動回路とを備えた構成とする。（６）光ディスク装置として、記録データを生成する記録データ生成手段（該当実施例：符号５）と、記録動作の基準となる記録クロックを生成する第１のクロック生成手段（該当実施例：符号３）と、上記生成された記録クロックを分周する第１の分周手段（該当実施例：符号２２）と、上記記録クロックに基づき記録タイミング用制御信号を生成する制御信号生成手段（該当実施例：符号４）と、周波数可変型発振手段（該当実施例：符号１０）と該発振手段の出力を分周する第２の分周手段（該当実施例：符号２１）を有し該発振手段の分周された出力と上記分周された記録クロック及び該発振手段の分周された出力と上記記録データに基づき上記レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段（該当実施例：符号７ｅ）と、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成する波形生成手段（該当実施例：符号１１）と、上記波形生成手段への上記記録データの供給タイミングと上記第２のクロック生成手段への上記分周された記録クロックの供給タイミングを、上記記録タイミング用制御信号に基づき時分割で切換える切換え手段（該当実施例：符号６）とを備え、記録時、上記分周された記録クロックと上記記録データを同一の信号線により時分割で、それぞれ上記第２のクロック生成手段と上記波形生成手段とに供給し、該第２のクロック生成手段では、上記分周された記録クロックの入力期間では、該分周された記録クロックと上記発振手段の分周された出力との周波数誤差信号を選択して加算し、記録データの入力期間では、該記録データと上記発振手段の分周された出力との位相誤差信号を選択して加算し、上記記録クロックに同期した発光クロックを生成するレーザー駆動回路（該当実施例：符号１ｂ、２ｅ）と、上記レーザー駆動回路により駆動されるレーザーダイオード（該当実施例：符号１２）と、対物レンズを備え上記レーザーダイオードからのレーザー光を光ディスクの記録面に照射する光学系と、少なくとも上記レーザーダイオードと上記光学系を含んで成るピックアップを移動させるピックアップ移動機構と、光ディスクを回転させるスピンドルモータと、該スピンドルモータを駆動するモータ駆動回路とを備えた構成とする。（７）光ディスクにデータを記録するためにレーザーダイオードを駆動するレーザー駆動方法として、記録データの生成と、記録動作の基準となる記録クロックの生成と、該記録クロックに基づき記録タイミング用制御信号の生成とを行うステップと、上記記録データの供給タイミングと上記記録クロックの供給タイミングとを、上記記録タイミング用制御信号に基づき時分割で切換えて供給するステップと、少なくとも上記供給された記録クロックに基づき、上記レーザーダイオードの発光タイミングを決定するための発光クロックを生成するステップと、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成するステップと、上記生成した記録波形をレーザーダイオードに供給するステップとを経て、上記レーザーダイオードの駆動を行う。（８）レーザー駆動方法として、記録データの生成と、記録動作の基準となる記録クロックの生成と、該記録クロックに基づき記録タイミング用制御信号の生成と、該記録クロックの分周とを行うステップと、上記記録データの供給タイミングと上記分周された記録クロックの供給タイミングとを、上記記録タイミング用制御信号に基づき時分割で切換えて供給するステップと、上記分周された記録クロック及び上記記録データに基づき、レーザーダイオードの発光タイミングを決定するための発光クロックを生成するステップと、上記記録データと上記発光クロックとに基づきレーザー発光の記録波形を生成するステップと、上記生成した記録波形をレーザーダイオードに供給するステップとを経て、上記レーザーダイオードの駆動を行う。
【０００７】
上記において、上記記録クロックは記録開始前に供給し、該記録クロックと発光クロックとを同期させる。記録中は記録データと発光クロックとの位相差を検出し同期させる。これにより、記録中は記録クロックの供給を不要にし該記録クロックに起因するノイズをなくす。
【０００８】
【発明の実施の形態】
以下、本発明の実施例につき、図面を用いて説明する。
図１及び図２は本発明の第１の実施例の説明図である。図１はレーザー駆動回路の構成図、図２は信号波形説明図である。
図１において、１ａは信号処理回路、２ａはレーザーダイオードを発光駆動するためのレーザーダイオード駆動回路、３は、記録動作の基準となる記録クロックの生成を行う第１のクロック生成手段としての記録クロック生成回路、４は、記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成して出力する制御信号生成手段としての記録タイミング信号生成回路、５は、同じく記録クロックに基づき記録データを変調して出力する記録生成手段としての記録データ変調回路、６は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき、信号処理回路１ａ側からレーザーダイオード駆動回路２ａ側への記録クロックの供給タイミングと記録データの供給タイミングとを時分割で切換える切換え手段としてのスイッチ、７ａは、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段としての位相同期発振器（ＰＬＬ）、８は位相同期発振器（ＰＬＬ）７ａを構成する位相比較器、９は同じく低域通過フィルタ（ＬＰＦ）、１０は同じく周波数可変型発振手段としての周波数電圧制御発振器（ＶＣＯ）、１１は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と上記記録データと上記発光クロックとに基づき、レーザーダイオードを発光させるための記録波形を生成する波形生成手段としての記録発光波形生成回路、１２はレーザーダイオードである。上記位相比較器８は、位相比較タイミングが不連続でも位相比較が可能な構成を有する。
【０００９】
上記構成において、記録クロック生成回路３で生成された記録クロックは、記録タイミング信号生成回路４と記録データ変調回路５とスイッチ６とに入力される。記録タイミング信号生成回路４では該入力された記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成し、記録データ変調回路では該入力された記録クロックに基づき記録データの変調を行う。該生成された記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と該変調された記録データも記録クロックとともにスイッチ６に入力される。該スイッチ６内では、入力された記録クロックと記録データのレーザーダイオード駆動回路２ａ側への供給タイミングを、記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき時分割で切換える。切換えられた記録クロックと記録データは時分割多重された信号として同じ信号線上を伝送され、レーザーダイオード駆動回路２ａ内の位相同期発振器（ＰＬＬ）７ａと記録発光波形生成回路１１とに供給される。位相同期発振器（ＰＬＬ）７ａ内では、入力された記録クロックに基づき位相比較器８と低域通過フィルタ（ＬＰＦ）９と周波数電圧制御発振器（ＶＣＯ）１０により発光クロックを生成するとともに、記録開始前の期間（記録クロックの入力期間）においては該周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録クロックの位相比較を行って位相差を検出し該両者の同期をとり、記録期間においては該周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録データの位相比較を行って位相差を検出しこれに基づき該両者の同期をとる。記録発光波形生成回路１１には、上記記録データの他、上記記録タイミング信号生成回路４からの記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、上記位相同期発振器（ＰＬＬ）７ａで生成された発光クロックとが入力される。該記録発光波形生成回路１１では、入力された記録データと記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と発光クロックとに基づき、レーザーダイオードを駆動して発光させるための記録波形を生成し出力する。
【００１０】
図２は、図１のレーザー駆動回路における信号波形説明図である。
図２において、（ａ）は記録クロックの信号波形、（ｂ）は記録データの信号波形、（ｃ）は記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））の波形、（ｄ）は記録クロックと記録データの多重信号の波形、（ｅ）は、発光クロックと記録クロックの位相誤差及び発光クロックと記録データの位相誤差の信号波形である。記録開始前期間（記録クロックの入力期間）と記録期間とにおいて、（ｅ）の位相誤差をなくすようにして同期がとられ、記録開始前期間（記録クロックの入力期間）で周波数電圧制御発振器（ＶＣＯ）１０の出力と記録クロックとの同期がとられ、記録期間中は該周波数電圧制御発振器（ＶＣＯ）１０の出力と記録データとの同期がとられて発光パルスが生成される。
【００１１】
上記第１の実施例によれば、記録期間では記録クロックの供給を断って記録動作を行うため、記録クロックに基づくノイズの影響をなくした安定な状態で記録を行うことができる。
【００１２】
図３及び図４は本発明の第２の実施例の説明図である。図３はレーザー駆動回路の構成図、図４は信号波形の説明図である。
本第２の実施例は、記録クロックの入力期間において位相比較と周波数比較の双方を行う場合の例である。
図３において、１ａは信号処理回路、２ｂはレーザーダイオードを発光駆動するためのレーザーダイオード駆動回路、３は、記録動作の基準となる記録クロックの生成を行う第１のクロック生成手段としての記録クロック生成回路、４は、記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成して出力する制御信号生成手段としての記録タイミング信号生成回路、５は、同じく記録クロックに基づき記録データを変調して出力する記録データ生成手段としての記録データ変調回路、６は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき、信号処理回路１ａ側からレーザーダイオード駆動回路２ｂ側への記録クロックの供給タイミングと記録データの供給タイミングとを時分割で切換える切換え手段としてのスイッチ、７ｂは、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段としての位相同期発振器（ＰＬＬ）、８は、位相同期発振器（ＰＬＬ）７ｂを構成する位相比較器、９は同じく低域通過フィルタ（ＬＰＦ）、１０は同じく周波数可変型発振手段としての周波数電圧制御発振器（ＶＣＯ）、１１は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と上記記録データと上記発光クロックとに基づき、レーザーダイオードを発光させる記録波形を生成する波形生成手段としての記録発光波形生成回路、１２はレーザーダイオード、１３は、入力される記録クロックと周波数電圧制御発振器（ＶＣＯ）１０の出力との周波数比較を行い周波数誤差を検出する周波数比較器、１４は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づいて切換えられ、記録クロックが入力されている期間中は上記周波数比較が行われるようにするためのスイッチ、１５は加算器である。上記位相比較器８は、位相比較タイミングが不連続でも位相比較が可能な構成を有する。
【００１３】
上記構成において、記録クロック生成回路３で生成された記録クロックは、記録タイミング信号生成回路４と記録データ変調回路５とスイッチ６とに入力される。記録タイミング信号生成回路４では該入力された記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成し、記録データ変調回路では該入力された記録クロックに基づき記録データの変調を行う。該生成された記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と該変調された記録データも記録クロックとともにスイッチ６に入力される。該スイッチ６内では、入力された記録クロックと記録データのレーザーダイオード駆動回路２ｂ及び周波数比較器１３側への供給タイミングを、記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき時分割で切換える。切換えられた記録クロックと記録データは時分割多重された信号として、同じ信号線上を伝送され、レーザーダイオード駆動回路２ｂ内の位相同期発振器（ＰＬＬ）７ｂと記録発光波形生成回路１１と、周波数比較器１３に供給される。位相同期発振器（ＰＬＬ）７ｂ内では、入力された記録クロックに基づき位相比較器８と低域通過フィルタ（ＬＰＦ）９と周波数電圧制御発振器（ＶＣＯ）１０により発光クロックを生成するとともに、記録開始前の期間（記録クロックの入力期間）においては位相比較器８において周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録クロックの位相比較を行って位相差を検出した後、これに基づき該両者の同期をとり、記録期間においては周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録データの位相比較を行って位相差を検出しこれに基づき該両者の同期をとる。記録開始前の期間（記録クロックの入力期間）においては周波数比較器１３において周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録データの周波数比較が行われ、周波数誤差が検出される。該周波数誤差の信号と上記位相差の信号は加算器１５に入力される。周波数電圧制御発振器（ＶＣＯ）１０からは上記周波数誤差と上記位相差に基づき同期がとられた発光クロックが出力される。記録発光波形生成回路１１には、上記記録データの他、上記記録タイミング信号生成回路４からの記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、上記位相同期発振器（ＰＬＬ）７ｂで生成された発光クロックとが入力される。該記録発光波形生成回路１１では、入力された記録データと記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と発光クロックとに基づき、レーザーダイオードを駆動して発光させるための記録波形を生成し出力する。
【００１４】
図４は、図３のレーザー駆動回路における信号波形の説明図である。
図４において、（ａ）は記録クロックの信号波形、（ｂ）は記録データの信号波形、（ｃ）は記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））の波形、（ｄ）は記録クロックと記録データの多重信号の波形、（ｅ）は周波数電圧制御発振器（ＶＣＯ）１０の出力と記録クロックの周波数誤差の信号波形、（ｆ）は、周波数電圧制御発振器（ＶＣＯ）１０の出力と記録クロックの位相誤差及び周波数電圧制御発振器（ＶＣＯ）１０の出力と記録データの位相誤差の信号波形である。記録開始前期間（記録クロックの入力期間）では、（ｅ）の位相誤差と（ｆ）の周波数誤差との両方をなくすように同期がとられ、記録期間では、（ｆ）の位相誤差をなくすようにして同期がとられる。
【００１５】
上記第２の実施例によっても、記録期間では記録クロックの供給を断って記録動作を行うため、記録クロックに基づくノイズの影響をなくした安定な状態で記録を行うことができる。特に、周波数比較器を設けることにより、位相同期発振器（ＰＬＬ）における引き込み時間を短縮することができる。また、広範囲の周波数において短時間の引き込みが可能となる。
【００１６】
図５は本発明の第３の実施例の説明図である。
本第３の実施例は、記録クロックの入力期間において位相比較と周波数比較のいずれか一方を選択するようにした場合の例である。
図５において、１ａは信号処理回路、２ｃはレーザーダイオードを発光駆動するためのレーザーダイオード駆動回路である。信号処理回路１ａ内の構成は上記第１、第２の実施例の場合と同様である。レーザーダイオード駆動回路２ｃ内において、７ｃは、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段としての位相同期発振器（ＰＬＬ）、８は、位相同期発振器（ＰＬＬ）７ｃを構成する位相比較器、９は同じく低域通過フィルタ（ＬＰＦ）、１０は同じく周波数可変型発振手段としての周波数電圧制御発振器（ＶＣＯ）、１１は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と上記記録データと上記発光クロックとに基づき、レーザーダイオードを発光させる記録波形を生成する波形生成手段としての記録発光波形生成回路、１２はレーザーダイオード、１３は、入力される記録クロックと周波数電圧制御発振器（ＶＣＯ）１０の出力との周波数比較を行い周波数誤差を検出する周波数比較器、１６は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき、記録クロックが入力されている期間において上記位相比較器８の出力と上記周波数比較器１３の出力とを択一的に選択するためのスイッチである。上記位相比較器８は、上記周波数電圧制御発振器（ＶＣＯ）の出力と記録クロック及び記録データとの位相比較を行い各位相誤差を検出するものであり、位相比較タイミングが不連続でも位相比較が可能である。
【００１７】
上記構成において、記録クロック生成回路３で生成された記録クロックは、記録タイミング信号生成回路４と記録データ変調回路５とスイッチ６とに入力される。記録タイミング信号生成回路４では該入力された記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成し、記録データ変調回路では該入力された記録クロックに基づき記録データの変調を行う。該生成された記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と該変調された記録データも記録クロックとともにスイッチ６に入力される。該スイッチ６内では、入力された記録クロックと記録データのレーザーダイオード駆動回路２ｃ及び周波数比較器１３側への供給タイミングを、記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき時分割で切換える。切換えられた記録クロックと記録データは時分割多重された信号として、同じ信号線上を伝送され、レーザーダイオード駆動回路２ｃ内の位相同期発振器（ＰＬＬ）７ｃと記録発光波形生成回路１１と、周波数比較器１３に供給される。位相同期発振器（ＰＬＬ）７ｃ内では、入力された記録クロックに基づき位相比較器８と低域通過フィルタ（ＬＰＦ）９と周波数電圧制御発振器（ＶＣＯ）１０により発光クロックを生成するとともに、記録開始前の期間（記録クロックの入力期間）においては位相比較器８において周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録クロックとの位相比較を行って位相差を検出し、記録期間においては周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録データとの位相比較を行って位相差を検出する。記録開始前の期間（記録クロックの入力期間）においては周波数比較器１３において周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録クロックとの周波数比較が行われ、周波数誤差が検出される。該周波数誤差の信号と上記位相差の信号はスイッチ１６に入力される。スイッチ１６では記録クロックの入力期間における上記周波数誤差信号と上記位相差信号のいずれかを選択する。周波数電圧制御発振器（ＶＣＯ）１０からはこれに基づき同期がとられた発光クロックが出力される。記録発光波形生成回路１１には、上記記録データの他、上記記録タイミング信号生成回路４からの記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、上記位相同期発振器（ＰＬＬ）７ｃで生成された発光クロックとが入力される。該記録発光波形生成回路１１では、入力された記録データと記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と発光クロックとに基づき、レーザーダイオードを駆動して発光させるための記録波形を生成し出力する。
【００１８】
上記第３の実施例によっても、記録期間では記録クロックの供給を断って記録動作を行うため、記録クロックに基づくノイズの影響をなくした安定な状態で記録を行うことができる。特に、スイッチ１６で周波数比較を選択した場合は、上記第２の実施例と同様、位相同期発振器（ＰＬＬ）における引き込み時間を短縮することができる。さらに、位相比較器８を用いる場合と周波数比較器１３を用いる場合とで独立して回路設計を行うことができ、容易に実現可能である。
【００１９】
図６及び図７は本発明の第４の実施例の説明図である。図６はレーザー駆動回路の構成図、図７は信号波形の説明図である。
本第４の実施例は、記録クロックの入力期間において位相比較と周波数比較の双方を行い、かつ、周波数比較出力の加算を切る際に低域通過フィルタ（ＬＰＦ）の出力をホールドするようにした場合の例である。
図６において、１ａは信号処理回路、２ｄはレーザーダイオードを発光駆動するためのレーザーダイオード駆動回路である。信号処理回路１ａ内の構成は上記第１、第２及び第３の実施例の場合と同様である。レーザーダイオード駆動回路２ｄ内において、７ｄは、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段としての位相同期発振器（ＰＬＬ）、８は、位相同期発振器（ＰＬＬ）７ｄを構成する位相比較器、９は低域通過フィルタ（ＬＰＦ）、１０は周波数可変型発振手段としての周波数電圧制御発振器（ＶＣＯ）、１１は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と上記記録データと上記発光クロックとに基づき、レーザーダイオードを発光させる記録波形を生成する波形生成手段としての記録発光波形生成回路、１２はレーザーダイオード、１３は、入力される記録クロックと周波数電圧制御発振器（ＶＣＯ）１０の出力との周波数比較を行い周波数誤差を検出する周波数比較器、１４は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づいて制御され、記録クロックが入力されている期間中は上記周波数比較が行われるように切換えるスイッチ、１５は加算器、２３は、低域通過フィルタ（ＬＰＦ）９の出力をホールドするサンプルホールド回路、１７、１８は記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））の位相を遅らせる遅延器、２０はサンプルホールド回路２３を制御する信号を形成する信号形成回路である。上記位相比較器８は、位相比較タイミングが不連続でも位相比較が可能な構成を有する。
【００２０】
上記構成において、記録クロック生成回路３で生成された記録クロックは、記録タイミング信号生成回路４と記録データ変調回路５とスイッチ６とに入力される。記録タイミング信号生成回路４では該入力された記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成し、記録データ変調回路では該入力された記録クロックに基づき記録データの変調を行う。該生成された記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と該変調された記録データも記録クロックとともにスイッチ６に入力される。該スイッチ６内では、入力された記録クロックと記録データのレーザーダイオード駆動回路２ｄ及び周波数比較器１３側への供給タイミングを、記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき時分割で切換える。切換えられた記録クロックと記録データは時分割多重された信号として、レーザーダイオード駆動回路２ｄ内の位相同期発振器（ＰＬＬ）７ｄと記録発光波形生成回路１１と、周波数比較器１３に供給される。位相同期発振器（ＰＬＬ）７ｄ内では、入力された記録クロックに基づき位相比較器８と低域通過フィルタ（ＬＰＦ）９と周波数電圧制御発振器（ＶＣＯ）１０により発光クロックを生成するとともに、記録開始前の期間（記録クロックの入力期間）においては位相比較器８において周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録クロックの位相比較を行って位相差を検出した後、これに基づき該両者の同期をとり、記録期間においては周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録データの位相比較を行って位相差を検出しこれに基づき該両者の同期をとる。記録開始前の期間（記録クロックの入力期間）においては周波数比較器１３において周波数電圧制御発振器（ＶＣＯ）１０の出力と入力された記録データの周波数比較が行われ、周波数誤差が検出される。該周波数誤差の信号と上記位相差の信号は加算器１５に入力される。周波数電圧制御発振器（ＶＣＯ）１０からは上記周波数誤差と上記位相差に基づき同期がとられた発光クロックが出力される。記録クロックの入力期間が終了する時、スイッチ１４により周波数比較器１３からの周波数誤差信号の加算が停止される。サンプルホールド回路２３はこの時、低域通過フィルタ（ＬＰＦ）９の出力をホールドし、周波数電圧制御発振器（ＶＣＯ）１０に対しスイッチ１４による切換えに基づく過渡信号が印加されないようにし、発光クロックが変動しないようにする。このときのサンプルホールド回路２３のホールド動作は信号形成回路２０で形成された信号により制御される。該信号形成回路２０では上記遅延器１８からの信号や記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））により出力信号が形成される。記録発光波形生成回路１１には、上記記録データの他、上記記録タイミング信号生成回路４からの記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、上記位相同期発振器（ＰＬＬ）７ｄで生成された発光クロックとが入力される。該記録発光波形生成回路１１では、入力された記録データと記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と発光クロックとに基づき、レーザーダイオードを駆動して発光させるための記録波形を生成し出力する。
【００２１】
図７は、図６のレーザー駆動回路における信号波形の説明図である。
図７において、（ａ）は記録クロックの信号波形、（ｂ）は記録データの信号波形、（ｃ）は記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））の波形、（ｄ）は遅延器１７の出力信号の波形、（ｅ）は遅延器１８の出力信号の波形、（ｆ）はサンプルホールド回路２１の出力信号の波形、（ｇ）は記録クロックと記録データの多重信号の波形、（ｈ）は周波数電圧制御発振器（ＶＣＯ）１０の出力と記録クロックの周波数誤差の信号波形、（ｉ）は、周波数電圧制御発振器（ＶＣＯ）１０の出力と記録クロックの位相誤差及び周波数電圧制御発振器（ＶＣＯ）１０の出力と記録データの位相誤差の信号波形である。記録開始前期間（記録クロックの入力期間）では、（ｈ）の周波数誤差と（ｉ）の位相誤差との両方をなくすように同期がとられ、記録期間では、（ｉ）の位相誤差をなくすようにして同期がとられる。
【００２２】
上記第４の実施例も、記録期間では記録クロックの供給を断って記録動作を行うため、記録クロックに基づくノイズの影響をなくした安定な状態で記録を行うことができる。特に、記録クロックの入力期間に周波数比較を行うため、位相同期発振器（ＰＬＬ）における引き込み時間を短縮することができる。また、周波数比較器からの出力信号の加算器１５への入力を断つ際、サンプルホールド回路２１により、周波数電圧制御発振器（ＶＣＯ）１０に過渡信号が印加されるのを防ぎ、発光クロックの変動を抑えることが可能となる。
なお、上記サンプルホールド回路２１により、周波数電圧制御発振器（ＶＣＯ）１０に過渡信号が印加されるのを防ぐ構成は、上記第３の実施例の構成に付加することも可能である。
【００２３】
図８及び図９は本発明の第５の実施例の説明図である。図８はレーザー駆動回路の構成図、図９はその信号波形の説明図である。
本第５の実施例は、分周した記録クロックを用い、該記録クロックの入力期間において位相比較と周波数比較の双方を行う場合の例である。
図８において、１ｂは信号処理回路、２ｅはレーザーダイオードを発光駆動するためのレーザーダイオード駆動回路、３は、記録動作の基準となる記録クロックの生成を行う第１のクロック生成手段としての記録クロック生成回路、４は、記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成して出力する制御信号生成手段としての記録タイミング信号生成回路、５は、同じく記録クロックに基づき記録データを変調し出力する記録データ生成手段としての記録データ変調回路、２２は記録クロックを分周する第１の分周手段としての分周回路、６は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき、信号処理回路１ｂ側からレーザーダイオード駆動回路２ｅ側への、分周された記録クロックの供給タイミングと記録データの供給タイミングとを時分割で切換える切換え手段としてのスイッチ、７ｅは、レーザーダイオードの発光タイミングを決定するための発光クロックを生成する第２のクロック生成手段としての位相同期発振器（ＰＬＬ）、８は、位相同期発振器（ＰＬＬ）７ｅを構成する位相比較器、９は低域通過フィルタ（ＬＰＦ）、１０は周波数可変型発振手段としての周波数電圧制御発振器（ＶＣＯ）、２１は、周波数電圧制御発振器（ＶＣＯ）１０の出力を分周する第２の分周手段としての分周回路、１１は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と上記記録データと上記発光クロックとに基づき、レーザーダイオードを発光させる記録波形を生成する波形生成手段としての記録発光波形生成回路、１２はレーザーダイオード、１３は、入力される分周された記録クロックと周波数電圧制御発振器（ＶＣＯ）１０の出力との周波数比較を行い周波数誤差を検出する周波数比較器、１４は、上記記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき、記録クロック（分周した記録クロック）が入力されている期間中は上記周波数比較が行われるように切換えるためのスイッチ、１５は加算器である。分周回路２２の分周比と分周回路２１の分周比は等しくしてある。また、上記位相比較器８は、位相比較タイミングが不連続でも位相比較が可能な構成を有する。
【００２４】
上記構成において、記録クロック生成回路３で生成された記録クロックは、記録タイミング信号生成回路４と記録データ変調回路５と分周回路２２とに入力される。記録タイミング信号生成回路４では該入力された記録クロックに基づき記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））を生成し、記録データ変調回路では該入力された記録クロックに基づき記録データの変調を行い、分周回路２２では記録クロックの分周を行う。分周された記録クロックと、生成された記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、変調された記録データはスイッチ６に入力される。該スイッチ６内では、入力された、分周された記録クロックと記録データの、レーザーダイオード駆動回路２ｅ及び周波数比較器１３側への供給タイミングを、記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））に基づき時分割で切換える。切換えられた、分周された記録クロックと記録データは時分割多重された信号として、同じ信号線上を伝送され、レーザーダイオード駆動回路２ｅ内の位相同期発振器（ＰＬＬ）７ｅと記録発光波形生成回路１１と、周波数比較器１３に供給される。位相同期発振器（ＰＬＬ）７ｅ内では、入力された記録クロックに基づき位相比較器８と低域通過フィルタ（ＬＰＦ）９と周波数電圧制御発振器（ＶＣＯ）１０により発光クロックを生成するとともに、記録開始前の期間、すなわち分周された記録クロックの入力期間においては位相比較器８において、周波数電圧制御発振器（ＶＣＯ）１０の出力を分周回路２１で分周した信号と分周した記録クロックとの位相比較を行って位相差を検出した後、これに基づき該両者の同期をとり、記録期間においては周波数電圧制御発振器（ＶＣＯ）１０の出力を分周した信号と、入力された記録データとの位相比較を行って位相差を検出しこれに基づき該両者の同期をとる。記録開始前の期間、すなわち分周された記録クロックの入力期間では、周波数比較器１３において周波数電圧制御発振器（ＶＣＯ）１０の出力を分周した信号と入力された記録データとの周波数比較が行われ、周波数誤差が検出される。該周波数誤差の信号と上記位相差の信号は加算器１５に入力される。周波数電圧制御発振器（ＶＣＯ）１０からは上記周波数誤差と上記位相差に基づき同期がとられた発光クロックが出力される。記録発光波形生成回路１１には、上記記録データの他、上記記録タイミング信号生成回路４からの記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と、上記位相同期発振器（ＰＬＬ）７ｅで生成された発光クロックとが入力される。該記録発光波形生成回路１１では、入力された記録データと記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））と発光クロックとに基づき、レーザーダイオードを駆動し発光させるための記録波形を生成し出力する。
【００２５】
図９は、図８のレーザー駆動回路における信号波形の説明図である。
図９において、（ａ）は記録クロックの信号波形、（ｂ）は記録データの信号波形、（ｃ）は記録タイミング用制御信号（記録再生切替え信号（Ｒ／ＷＢ））の波形、（ｄ）は、分周した記録クロックと記録データの多重信号波形、（ｅ）は、周波数電圧制御発振器（ＶＣＯ）１０の出力を分周した信号と分周した記録クロックとの周波数誤差の信号波形、（ｆ）は、周波数電圧制御発振器（ＶＣＯ）１０の出力を分周した信号と分周した記録クロックとの位相誤差及び周波数電圧制御発振器（ＶＣＯ）１０の出力を分周した信号と記録データとの位相誤差の信号波形である。記録開始前期間（分周した記録クロックの入力期間）では、（ｅ）の位相誤差と（ｆ）の周波数誤差との両方をなくすように同期がとられ、記録期間では、（ｆ）の位相誤差をなくすようにして同期がとられる。
【００２６】
上記第５の実施例によっても、記録期間では記録クロックの供給を断つため、記録クロックに基づくノイズの影響をなくし安定な記録を行うことができる。特に、信号処理回路１ｂからレーザーダイオード駆動回路２ｅに送出するクロック周波数を発光クロックより低くすることができるため、高速記録に適する。また、周波数比較器を設けた構成のため、位相同期発振器（ＰＬＬ）における引き込み時間を短縮することができる。
【００２７】
なお、上記第１〜第５の実施例における各スイッチは論理回路により構成するものとする。
また、上記分周した記録クロックと周波数電圧制御発振器（ＶＣＯ）の出力を分周した信号とを用いる構成は、例えば上記第１の実施例、上記第３の実施例または上記第４の実施例の構成にも適用可能である。
【００２８】
【発明の効果】
本発明によれば、光ディスク装置において、記録クロックに基づくノイズの影響をなくした安定な記録が可能となる。
【図面の簡単な説明】
【図１】本発明の第１の実施例としてのレーザー駆動回路の構成例を示す図である。
【図２】図１のレーザー駆動回路の信号波形説明図である。
【図３】本発明の第２の実施例としてのレーザー駆動回路の構成例を示す図である。
【図４】図３のレーザー駆動回路の信号波形説明図である。
【図５】本発明の第３の実施例を示す図である。
【図６】本発明の第４の実施例としてのレーザー駆動回路の構成例を示す図である。
【図７】図６のレーザー駆動回路の信号波形説明図である。
【図８】本発明の第５の実施例としてのレーザー駆動回路の構成例を示す図である。
【図９】図８のレーザー駆動回路の信号波形説明図である。
【図１０】従来のレーザー駆動回路の構成例を示す図である。
【符号の説明】
１ａ、１ｂ、１ｃ…信号処理回路、２ａ、２ｂ、２ｃ、２ｄ、２ｅ、２’…レーザーダイオード駆動回路、３…記録クロック生成回路、４…記録タイミング信号生成回路、５…記録データ変調回路、６、１４、１６…スイッチ、７ａ、７ｂ、７ｃ、７ｄ、７ｅ…位相同期発振器（ＰＬＬ）、８…位相比較器、９…低域通過フィルタ（ＬＰＦ）、１０…周波数電圧制御発振器（ＶＣＯ）、１１…記録発光波形生成回路、１２…レーザーダイオード、１３…周波数比較器、１５…加算器、１７、１８…遅延器、２１、２２…分周回路、２３…サンプルホールド回路。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technology for recording data information by irradiating an optical disk as a recording medium with a laser beam.
[0002]
[Prior art]
FIG. 10 shows a conventional example of a recording circuit related to the recording technique of the present invention. In FIG. 10, 1c is a signal processing circuit, 2 'is a diode driving circuit for driving a laser diode to emit light, 3 is a recording clock generating circuit for generating a recording clock which is a reference of a recording operation, and 4 is a recording clock. A recording timing signal generating circuit that generates and outputs a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the recording data; and a recording data modulation circuit that modulates recording data based on a recording clock and outputs the same. , 7a are a phase-locked oscillator (PLL) for generating an emission clock for determining the emission timing of the laser diode, 8 is a phase comparator constituting the PLL, 9 is a low-pass filter (LPF), and 10 is also a The frequency voltage controlled oscillator (VCO) 11 receives the recording timing control signal (recording / reproduction switching signal (R / WB) )), The recording data, and the light emission clock, a recording light emission waveform generation circuit for generating a recording waveform for causing the laser diode to emit light, and 12 is a laser diode. In the above configuration, the recording clock is input from the recording clock generation circuit 3 to the phase locked oscillator (PLL) 7a, and the recording data is input from the recording data modulation circuit 5 to the recording light emission waveform generation circuit 11. The recording clock and the recording data are supplied to a phase-locked oscillator (PLL) 7a and a recording light emission waveform generation circuit 11 in the optical pickup through separate signal lines. The phase-locked oscillator (PLL) 7a generates an emission clock based on the input recording clock. In addition to the recording data, the recording emission waveform generation circuit 11 includes a recording timing control signal (recording / reproduction switching signal (R / WB)) from the recording timing signal generation circuit 4 and the phase-locked oscillator (PLL) 7a. And the above-mentioned light emission clock. The recording / emission waveform generation circuit 11 generates a recording waveform for causing the laser diode to emit light based on the input recording data, the recording timing control signal (recording / reproduction switching signal (R / WB)), and the emission clock. Drive the laser diode 12.
[0003]
Patent documents describing the prior art related to the present invention include, for example, JP-A-11-283249 (Patent Document 1), JP-A-11-219524 (Patent Document 2), and JP-A-2001-43531. (Patent Document 3). Japanese Patent Application Laid-Open No. H11-283249 discloses a laser drive integrated circuit provided with storage means for storing drive waveform information for driving a laser diode in order to prevent a shift in switching timing and a decrease in error rate in an optical disk device. A configuration is described in which a drive waveform is restored based on information stored in the means and the drive waveform information in the storage means is selected based on a signal to be recorded on a disk. Japanese Patent Laying-Open No. 11-219524 describes a configuration in which a current switching control signal is changed to a code signal and transmitted in order to prevent a shift in switching timing and a decrease in error rate in an optical disk device. Japanese Patent Application Laid-Open No. 2001-43531 describes a configuration in which a recording strategy controllable laser driver for stably recording or reproducing data is provided close to a semiconductor laser in a recording and reproducing apparatus. In the configurations described in these publications, data and a clock are transmitted through separate transmission paths.
[0004]
[Patent Document 1]
JP-A-11-283249
[Patent Document 2]
JP-A-11-219524
[Patent Document 3]
JP 2001-43531 A
[0005]
[Problems to be solved by the invention]
In the prior art shown in FIG. 10, a high-frequency recording clock is always supplied to the optical pickup side even during the recording operation, and the recording clock generation circuit and the circuit in the optical pickup are connected by a long connection line. For this reason, noise due to the recording clock may interfere with other circuits (servo circuit, ATIP detection circuit, etc.) and reduce the recording stability. Also, in the techniques described in the above publications, since a high-frequency recording clock is always supplied to the optical pickup side during the recording operation, interference based on this may impair recording stability.
An object of the present invention is to reduce the influence of noise due to a recording clock in a laser diode drive in an optical disc device and to achieve a stable recording operation in view of the situation of the related art.
An object of the present invention is to provide a technique capable of solving such a problem.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a laser drive circuit capable of driving a laser diode to record data on an optical disc. To generate a recording light emission waveform for driving laser diode light emission, and cause the laser diode to emit light during a period without a recording clock to perform recording on an optical disk. The time division timing is determined by a recording timing control signal generated based on the recording clock. Specifically, (1) as a laser drive circuit (corresponding embodiment: reference numerals 1a, 1b, 2a, 2b, 2c, 2d, 2e), generation of recording data and generation of a recording clock as a reference of a recording operation. A first means for generating a recording timing control signal based on the recording clock (applicable embodiment: reference numerals 3, 4, and 5); and determining the light emission timing of the laser diode based at least on the recording clock. Means for generating a light emission clock (corresponding embodiment: reference numerals 7a, 7b, 7c, 7d, 7e) and a third means for generating a recording waveform of laser emission based on the recording data and the light emission clock. Means (corresponding embodiment: reference numeral 11), the supply timing of the recording data to the third means, and the supply timing of the recording clock to the second means. Means for switching in a time division manner on the basis of the control signal for recording timing of the means (corresponding embodiment: reference numeral 6). In recording, the recording clock and the recording data are time-divisionally divided into the first means. From the second means and the third means, respectively. (2) As a laser drive circuit (corresponding embodiment: reference numerals 1a, 1b, 2a, 2b, 2c, 2d, 2e), a recording data generating means (corresponding embodiment: reference numeral 5) for generating recording data; A first clock generating means for generating a reference recording clock (corresponding embodiment: reference numeral 3); a control signal generating means for generating a recording timing control signal based on the recording clock (corresponding embodiment: reference numeral 4); A second clock generating means (corresponding embodiment: reference numerals 7a, 7b, 7c, 7d, 7e) for generating an emission clock for determining an emission timing of the laser diode based on at least the recording clock; A waveform generating means for generating a recording waveform of laser emission based on the data and the emission clock (corresponding embodiment: reference numeral 11); Switching means for switching the supply timing of the recording data and the supply timing of the recording clock to the second clock generation means in a time division manner based on the control signal for recording timing (corresponding embodiment: reference numeral 6); At the time of recording, the recording clock and the recording data can be supplied to the second clock generating means and the waveform generating means in a time-division manner through the same signal line. (3) As a laser driving circuit (corresponding embodiment: reference numerals 1b and 2e), a recording data generating means (corresponding embodiment: reference numeral 5) for generating recording data, and a first for generating a recording clock as a reference of a recording operation. Clock generating means (corresponding embodiment: reference numeral 3), first frequency dividing means (corresponding embodiment: reference numeral 22) for dividing the generated recording clock, and a recording timing control signal based on the recording clock. , A variable frequency oscillating means, and a second frequency dividing means (frequency: 21) for dividing the output of the oscillating means. Based on the divided output of the oscillating means and the divided recording clock, and the emission clock for determining the emission timing of the laser diode based on the divided output of the oscillating means and the recording data. A second clock generating means (corresponding embodiment: reference numeral 7e), a waveform generating means (corresponding embodiment: reference numeral 11) for generating a recording waveform of laser emission based on the recording data and the light emission clock, Switching means for switching the supply timing of the recording data to the generating means and the supply timing of the divided recording clock to the second clock generating means in a time-division manner based on the control signal for recording timing : During recording, the frequency-divided recording clock and the recording data are supplied to the second clock generating means and the waveform generating means in a time-division manner by the same signal line, respectively. In the second clock generation means, during the input period of the divided recording clock, the divided recording clock and the divided output of the oscillation means are output. A wave number error signal is selected and added, and during a recording data input period, a phase error signal between the recording data and the divided output of the oscillating means is selected and added, and a light emission clock synchronized with the recording clock is selected. Is generated. (4) As an optical disc apparatus having a configuration capable of recording data on an optical disc by a laser, a recording data, a recording clock as a reference for a recording operation, and a recording timing control signal based on the recording clock are generated. And a second means for generating an emission clock for determining the emission timing of the laser diode based on at least the recording clock (applicable embodiment: 3, 4, 5). : A reference numeral 7a, 7b, 7c, 7d, 7e), a third means (corresponding embodiment: reference numeral 11) for generating a recording waveform of laser emission based on the recording data and the emission clock, and The supply timing of the recording data to the means and the supply timing of the recording clock to the second means are determined by the recording time of the first means. A fourth means (pertinent embodiment: reference numeral 6) for switching in a time-division manner based on a control signal for switching, and when recording, the recording clock and the recording data are time-divisionally divided from the first means by the first means. 2 and a laser driving circuit (corresponding embodiment: 1a, 1b, 2a, 2b, 2c, 2d, 2e) for supplying to the third means, and a laser diode driven by the laser driving circuit (corresponding to Example: reference numeral 12), an optical system having an objective lens and irradiating the recording surface of the optical disk with laser light from the laser diode, and a pickup moving mechanism for moving a pickup including at least the laser diode and the optical system. And a spindle motor for rotating the optical disk, and a motor drive circuit for driving the spindle motor. (5) As an optical disk device, a recording data generating means (corresponding embodiment: reference numeral 5) for generating recording data, and a first clock generating means (corresponding embodiment: reference numeral 3) for generating a recording clock serving as a reference of a recording operation ), A control signal generating means for generating a recording timing control signal based on the recording clock (corresponding embodiment: reference numeral 4), and an emission clock for determining the emission timing of the laser diode based on at least the recording clock Clock generating means (corresponding embodiment: reference numerals 7a, 7b, 7c, 7d, 7e), and waveform generating means (corresponding embodiment: generating a recording waveform of laser emission based on the recording data and the emission clock) Example: Reference numeral 11), the supply timing of the recording data to the waveform generation means, and the supply timing to the second clock generation means Switching means for switching the supply timing of the recording clock in a time-division manner on the basis of the control signal for recording timing (corresponding embodiment: reference numeral 6). In recording, the recording clock and the recording data are connected by the same signal line. A laser drive circuit (corresponding embodiment: 1a, 1b, 2a, 2b, 2c, 2d, 2e) which can be supplied to the second clock generating means and the waveform generating means in a time-division manner, respectively; A laser diode driven by a drive circuit (corresponding embodiment: reference numeral 12), an optical system having an objective lens and irradiating the recording surface of the optical disk with laser light from the laser diode, and at least the laser diode and the optical system. A pickup moving mechanism for moving the pickup, and a spindle motor for rotating the optical disk. When, a configuration in which a motor driving circuit for driving the spindle motor. (6) As an optical disk device, a recording data generating means (corresponding embodiment: reference numeral 5) for generating recording data, and a first clock generating means (corresponding embodiment: reference numeral 3) for generating a recording clock serving as a reference of a recording operation. ), First frequency dividing means for dividing the generated recording clock (corresponding embodiment: reference numeral 22), and control signal generating means for generating a recording timing control signal based on the recording clock (corresponding embodiment) 4), a variable frequency oscillating means (corresponding embodiment: reference numeral 10), and a second frequency dividing means (corresponding embodiment: reference numeral 21) for dividing the output of the oscillating means. Generating a second emission clock for determining the emission timing of the laser diode based on the divided output, the divided recording clock, and the divided output of the oscillating means and the recording data; A lock generating unit (corresponding embodiment: reference numeral 7e); a waveform generating unit (corresponding embodiment: reference numeral 11) for generating a recording waveform of laser emission based on the recording data and the emission clock; Switching means for switching the supply timing of the recording data and the supply timing of the divided recording clock to the second clock generation means in a time-division manner based on the control signal for recording timing (corresponding embodiment: reference numeral 6) During recording, the divided recording clock and the recording data are supplied to the second clock generating means and the waveform generating means in a time-division manner through the same signal line, respectively. In the clock generation means, during the input period of the divided recording clock, a frequency error signal between the divided recording clock and the divided output of the oscillation means is output. Is selected and added, and during the recording data input period, a phase error signal between the recording data and the frequency-divided output of the oscillating means is selected and added to generate an emission clock synchronized with the recording clock. A laser drive circuit (corresponding embodiment: reference numerals 1b and 2e), a laser diode (corresponding embodiment: reference numeral 12) driven by the laser drive circuit, and an objective lens are provided. An optical system for irradiating a surface, a pickup moving mechanism for moving at least a pickup including the laser diode and the optical system, a spindle motor for rotating an optical disk, and a motor drive circuit for driving the spindle motor. Configuration. (7) As a laser driving method for driving a laser diode to record data on an optical disk, generation of recording data, generation of a recording clock serving as a reference for a recording operation, and generation of a recording timing control signal based on the recording clock. Performing the generation, supplying the recording data supply timing and the recording clock supply timing in a time division manner based on the recording timing control signal, and supplying the recording data supply timing. Generating an emission clock for determining the emission timing of the laser diode, generating a recording waveform of laser emission based on the recording data and the emission clock, and transmitting the generated recording waveform to the laser diode. Supplying the laser For driving the diode. (8) As a laser driving method, a step of generating recording data, generating a recording clock serving as a reference of a recording operation, generating a recording timing control signal based on the recording clock, and dividing the recording clock. Supplying the recording data supply timing and the divided recording clock supply timing in a time-division manner based on the recording timing control signal; and supplying the divided recording clock and the recording Generating a light emission clock for determining a light emission timing of a laser diode based on the data; generating a laser emission recording waveform based on the recording data and the light emission clock; Driving the laser diode through the step of supplying to the diode
[0007]
In the above, the recording clock is supplied before the start of recording, and the recording clock and the emission clock are synchronized. During recording, the phase difference between the recording data and the emission clock is detected and synchronized. This eliminates the need to supply a recording clock during recording and eliminates noise due to the recording clock.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIGS. 1 and 2 are explanatory diagrams of a first embodiment of the present invention. FIG. 1 is a configuration diagram of a laser drive circuit, and FIG. 2 is an explanatory diagram of a signal waveform.
In FIG. 1, 1a is a signal processing circuit, 2a is a laser diode driving circuit for driving a laser diode to emit light, and 3 is a recording clock as a first clock generating means for generating a recording clock as a reference of a recording operation. The generating circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the recording clock, and outputs the recording timing signal as a control signal generating means. A recording data modulation circuit 6 as recording generation means for modulating recording data based on the recording data and outputting the data from the signal processing circuit 1a based on the recording timing control signal (recording / reproduction switching signal (R / WB)). The supply timing of the recording clock and the supply timing of the recording data to the diode drive circuit 2a are time-divided. A switch 7a as a switching means for switching, a phase-locked oscillator (PLL) as a second clock generation means for generating an emission clock for determining the emission timing of the laser diode, and 8 a phase-locked oscillator (PLL) 7a The phase comparator, 9 is a low-pass filter (LPF), 10 is a frequency voltage controlled oscillator (VCO) also as a variable frequency oscillating means, and 11 is the recording timing control signal (recording / reproduction switching signal ( R / WB)), a recording light emission waveform generation circuit as a waveform generation means for generating a recording waveform for causing a laser diode to emit light based on the recording data and the light emission clock, and 12 is a laser diode. The phase comparator 8 has a configuration capable of comparing phases even when the phase comparison timing is discontinuous.
[0009]
In the above configuration, the recording clock generated by the recording clock generation circuit 3 is input to the recording timing signal generation circuit 4, the recording data modulation circuit 5, and the switch 6. The recording timing signal generation circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the input recording clock, and the recording data modulation circuit generates recording data based on the input recording clock. Modulation. The generated recording timing control signal (recording / reproduction switching signal (R / WB)) and the modulated recording data are also input to the switch 6 together with the recording clock. In the switch 6, the supply timing of the input recording clock and the recording data to the laser diode drive circuit 2a is switched in a time division manner based on a recording timing control signal (recording / reproduction switching signal (R / WB)). The switched recording clock and recording data are transmitted on the same signal line as time-division multiplexed signals, and are supplied to a phase locked oscillator (PLL) 7a and a recording light emission waveform generation circuit 11 in the laser diode driving circuit 2a. In the phase-locked oscillator (PLL) 7a, an emission clock is generated by a phase comparator 8, a low-pass filter (LPF) 9, and a frequency-voltage controlled oscillator (VCO) 10 based on the input recording clock, and before the recording starts. In the period (recording clock input period), the phase of the output of the frequency voltage controlled oscillator (VCO) 10 is compared with the input recording clock to detect a phase difference, and the two are synchronized. The phase of the output of the frequency voltage controlled oscillator (VCO) 10 is compared with the input recording data to detect a phase difference, and the two are synchronized based on this. In addition to the recording data, the recording emission waveform generation circuit 11 includes a recording timing control signal (recording / reproduction switching signal (R / WB)) from the recording timing signal generation circuit 4 and the phase-locked oscillator (PLL) 7a. And the light emission clock generated in step (1). The recording light emission waveform generation circuit 11 records a recording waveform for driving a laser diode to emit light based on the input recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)), and a light emission clock. Generate and output
[0010]
FIG. 2 is an explanatory diagram of signal waveforms in the laser drive circuit of FIG.
2A shows a recording clock signal waveform, FIG. 2B shows a recording data signal waveform, FIG. 2C shows a recording timing control signal (recording / reproduction switching signal (R / WB)) waveform, and FIG. Shows the waveform of the multiplexed signal of the recording clock and the recording data, and (e) shows the signal waveform of the phase error between the emission clock and the recording clock and the phase error between the emission clock and the recording data. In the pre-recording start period (recording clock input period) and the recording period, synchronization is achieved so as to eliminate the phase error of (e), and in the pre-recording start period (recording clock input period), the frequency voltage control oscillator ( The output of the VCO 10 is synchronized with the recording clock, and during the recording period, the output of the frequency voltage controlled oscillator (VCO) 10 is synchronized with the recording data to generate a light emission pulse.
[0011]
According to the first embodiment, during the recording period, the supply of the recording clock is cut off to perform the recording operation, so that the recording can be performed in a stable state without the influence of noise based on the recording clock.
[0012]
FIGS. 3 and 4 are explanatory diagrams of a second embodiment of the present invention. FIG. 3 is a configuration diagram of a laser driving circuit, and FIG. 4 is an explanatory diagram of a signal waveform.
The second embodiment is an example in which both the phase comparison and the frequency comparison are performed during the input period of the recording clock.
In FIG. 3, 1a is a signal processing circuit, 2b is a laser diode driving circuit for driving a laser diode to emit light, and 3 is a recording clock as a first clock generating means for generating a recording clock serving as a reference of a recording operation. The generating circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the recording clock, and outputs the recording timing signal as a control signal generating means. A recording data modulating circuit 6 as a recording data generating means for modulating the recording data based on the recording data and outputting the same from the signal processing circuit 1a based on the recording timing control signal (recording / reproduction switching signal (R / WB)). The supply timing of the recording clock to the laser diode drive circuit 2b and the supply timing of the recording data A switch 7b as a switching means for switching by a splitter; a phase-locked oscillator (PLL) as a second clock generation means for generating an emission clock for determining the emission timing of the laser diode; and 8 a phase-locked oscillator (PLL). 9) a phase comparator constituting 7b, 9 a low-pass filter (LPF), 10 a frequency voltage controlled oscillator (VCO) also as a variable frequency oscillating means, and 11 a recording timing control signal (recording / reproducing). A recording light emission waveform generation circuit as a waveform generation means for generating a recording waveform for causing a laser diode to emit light based on the switching signal (R / WB), the recording data, and the light emission clock, 12 a laser diode, and 13 an input Frequency comparison between the output recording clock and the output of the frequency voltage controlled oscillator (VCO) 10. A frequency comparator 14 for detecting a frequency error is switched based on the recording timing control signal (recording / reproduction switching signal (R / WB)), and performs the frequency comparison during a period in which a recording clock is input. A switch 15 for controlling the operation is an adder. The phase comparator 8 has a configuration capable of comparing phases even when the phase comparison timing is discontinuous.
[0013]
In the above configuration, the recording clock generated by the recording clock generation circuit 3 is input to the recording timing signal generation circuit 4, the recording data modulation circuit 5, and the switch 6. The recording timing signal generation circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the input recording clock, and the recording data modulation circuit generates recording data based on the input recording clock. Modulation. The generated recording timing control signal (recording / reproduction switching signal (R / WB)) and the modulated recording data are also input to the switch 6 together with the recording clock. In the switch 6, the supply timing of the input recording clock and recording data to the laser diode drive circuit 2b and the frequency comparator 13 side is determined based on a recording timing control signal (recording / reproduction switching signal (R / WB)). Switching by time division. The switched recording clock and recording data are transmitted on the same signal line as time-division multiplexed signals, and a phase-locked oscillator (PLL) 7b in the laser diode driving circuit 2b, a recording light emission waveform generation circuit 11, a frequency comparator 13 is supplied. In the phase-locked oscillator (PLL) 7b, a phase comparator 8, a low-pass filter (LPF) 9, and a frequency-voltage controlled oscillator (VCO) 10 generate an emission clock based on the input recording clock, and before starting recording. In the period (input period of the recording clock), the phase comparator 8 compares the phase of the output of the frequency-voltage controlled oscillator (VCO) 10 with the input recording clock to detect a phase difference. During the recording period, the phase of the output of the frequency voltage controlled oscillator (VCO) 10 is compared with the input recording data to detect a phase difference, and based on this, the two are synchronized. In a period before the start of recording (recording clock input period), the frequency comparator 13 compares the frequency of the output of the frequency voltage controlled oscillator (VCO) 10 with the input recording data, and detects a frequency error. The signal of the frequency error and the signal of the phase difference are input to the adder 15. A frequency-voltage controlled oscillator (VCO) 10 outputs a light-emitting clock synchronized based on the frequency error and the phase difference. In addition to the recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)) from the recording timing signal generation circuit 4 and the phase-locked oscillator (PLL) 7 b And the light emission clock generated in step (1). The recording light emission waveform generation circuit 11 records a recording waveform for driving a laser diode to emit light based on the input recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)), and a light emission clock. Generate and output
[0014]
FIG. 4 is an explanatory diagram of signal waveforms in the laser drive circuit of FIG.
4A shows a recording clock signal waveform, FIG. 4B shows a recording data signal waveform, FIG. 4C shows a recording timing control signal (recording / reproduction switching signal (R / WB)) waveform, and FIG. Is a waveform of a multiplexed signal of a recording clock and recording data, (e) is a signal waveform of an output of the frequency voltage controlled oscillator (VCO) 10 and a frequency error of the recording clock, and (f) is a signal waveform of the frequency voltage controlled oscillator (VCO) 10. FIG. 3 is a signal waveform of a phase error between an output and a recording clock and a phase error between an output of a frequency voltage controlled oscillator (VCO) 10 and recording data. In the pre-recording start period (recording clock input period), synchronization is established so as to eliminate both the phase error of (e) and the frequency error of (f), and in the recording period, the phase error of (f) is eliminated. In this way, synchronization is achieved.
[0015]
According to the second embodiment as well, during the recording period, the supply of the recording clock is cut off to perform the recording operation, so that the recording can be performed in a stable state without the influence of noise based on the recording clock. In particular, by providing the frequency comparator, the pull-in time in the phase locked oscillator (PLL) can be reduced. Further, a short-time pull-in can be performed in a wide range of frequencies.
[0016]
FIG. 5 is an explanatory diagram of the third embodiment of the present invention.
The third embodiment is an example in which one of the phase comparison and the frequency comparison is selected during the input period of the recording clock.
In FIG. 5, reference numeral 1a denotes a signal processing circuit, and 2c denotes a laser diode drive circuit for driving the laser diode to emit light. The configuration inside the signal processing circuit 1a is the same as in the first and second embodiments. In the laser diode driving circuit 2c, reference numeral 7c denotes a phase-locked oscillator (PLL) as a second clock generating means for generating an emission clock for determining the emission timing of the laser diode, and 8 denotes a phase-locked oscillator (PLL). 7c is a phase comparator, 9 is a low-pass filter (LPF), 10 is a frequency-voltage controlled oscillator (VCO) also as a variable frequency oscillating means, 11 is the recording timing control signal (recording / reproduction switching). Signal (R / WB)), the recording data, and the light emission clock, a recording light emission waveform generation circuit as a waveform generation means for generating a recording waveform for causing a laser diode to emit light, 12 is a laser diode, and 13 is an input. Frequency comparison between the recording clock and the output of the frequency voltage controlled oscillator (VCO) 10. A frequency comparator 16 for detecting a frequency error, based on the recording timing control signal (recording / reproduction switching signal (R / WB)), outputs the output of the phase comparator 8 during the period in which the recording clock is being input. A switch for selectively selecting the output of the frequency comparator 13. The phase comparator 8 detects the phase error by comparing the phase of the output of the frequency voltage controlled oscillator (VCO) with the recording clock and the recording data, and enables the phase comparison even if the phase comparison timing is discontinuous. It is.
[0017]
In the above configuration, the recording clock generated by the recording clock generation circuit 3 is input to the recording timing signal generation circuit 4, the recording data modulation circuit 5, and the switch 6. The recording timing signal generation circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the input recording clock, and the recording data modulation circuit generates recording data based on the input recording clock. Modulation. The generated recording timing control signal (recording / reproduction switching signal (R / WB)) and the modulated recording data are also input to the switch 6 together with the recording clock. In the switch 6, the supply timing of the input recording clock and the recording data to the laser diode drive circuit 2c and the frequency comparator 13 side is determined based on a recording timing control signal (recording / reproduction switching signal (R / WB)). Switching by time division. The switched recording clock and recording data are transmitted on the same signal line as time-division multiplexed signals, and the phase-locked oscillator (PLL) 7c in the laser diode driving circuit 2c, the recording emission waveform generation circuit 11, the frequency comparator 13 is supplied. In the phase-locked oscillator (PLL) 7c, an emission clock is generated by a phase comparator 8, a low-pass filter (LPF) 9, and a frequency voltage controlled oscillator (VCO) 10 based on the input recording clock, and before the recording starts. In the period (recording clock input period), the phase comparator 8 compares the phase of the output of the frequency-voltage controlled oscillator (VCO) 10 with the input recording clock to detect a phase difference. The phase difference between the output of the voltage controlled oscillator (VCO) 10 and the input recording data is detected to detect a phase difference. In the period before the start of recording (input period of the recording clock), the frequency comparator 13 compares the frequency of the output of the frequency-voltage controlled oscillator (VCO) 10 with the input recording clock, and detects a frequency error. The signal of the frequency error and the signal of the phase difference are input to the switch 16. The switch 16 selects one of the frequency error signal and the phase difference signal during the recording clock input period. The frequency-voltage controlled oscillator (VCO) 10 outputs a synchronized light-emitting clock based on this. In addition to the recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)) from the recording timing signal generation circuit 4 and the phase-locked oscillator (PLL) 7 c And the light emission clock generated in step (1). The recording light emission waveform generation circuit 11 records a recording waveform for driving a laser diode to emit light based on the input recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)), and a light emission clock. Generate and output
[0018]
According to the third embodiment as well, during the recording period, the supply of the recording clock is cut off to perform the recording operation, so that the recording can be performed in a stable state without the influence of noise based on the recording clock. In particular, when the frequency comparison is selected by the switch 16, the pull-in time in the phase locked oscillator (PLL) can be reduced as in the second embodiment. Further, the circuit can be designed independently in the case where the phase comparator 8 is used and the case where the frequency comparator 13 is used, and can be easily realized.
[0019]
6 and 7 are explanatory diagrams of a fourth embodiment of the present invention. FIG. 6 is a configuration diagram of a laser driving circuit, and FIG. 7 is an explanatory diagram of a signal waveform.
In the fourth embodiment, both the phase comparison and the frequency comparison are performed during the input period of the recording clock, and the output of the low-pass filter (LPF) is held when the addition of the frequency comparison output is stopped. This is an example of the case.
In FIG. 6, reference numeral 1a denotes a signal processing circuit, and 2d denotes a laser diode drive circuit for driving the laser diode to emit light. The configuration inside the signal processing circuit 1a is the same as in the first, second and third embodiments. In the laser diode drive circuit 2d, 7d is a phase-locked oscillator (PLL) as a second clock generating means for generating an emission clock for determining the emission timing of the laser diode, and 8 is a phase-locked oscillator (PLL) 7d is a phase comparator, 9 is a low-pass filter (LPF), 10 is a frequency voltage controlled oscillator (VCO) as a variable frequency oscillating means, 11 is the recording timing control signal (recording / reproduction switching signal ( R / WB)), a recording light emission waveform generation circuit as a waveform generation means for generating a recording waveform for causing a laser diode to emit light based on the recording data and the light emission clock, 12 is a laser diode, and 13 is input recording. Frequency error between the clock and the output of the frequency voltage controlled oscillator (VCO) 10 The frequency comparator 14 to be detected is controlled based on the recording timing control signal (recording / reproduction switching signal (R / WB)) so that the frequency comparison is performed during a period in which a recording clock is input. A switch for switching, 15 is an adder, 23 is a sample-and-hold circuit for holding the output of the low-pass filter (LPF) 9, and 17 and 18 are phases of a recording timing control signal (recording / reproduction switching signal (R / WB)). Is a signal forming circuit for forming a signal for controlling the sample-and-hold circuit 23. The phase comparator 8 has a configuration capable of comparing phases even when the phase comparison timing is discontinuous.
[0020]
In the above configuration, the recording clock generated by the recording clock generation circuit 3 is input to the recording timing signal generation circuit 4, the recording data modulation circuit 5, and the switch 6. The recording timing signal generation circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the input recording clock, and the recording data modulation circuit generates recording data based on the input recording clock. Modulation. The generated recording timing control signal (recording / reproduction switching signal (R / WB)) and the modulated recording data are also input to the switch 6 together with the recording clock. In the switch 6, the supply timing of the input recording clock and recording data to the laser diode drive circuit 2d and the frequency comparator 13 side is determined based on a recording timing control signal (recording / reproduction switching signal (R / WB)). Switching by time division. The switched recording clock and recording data are supplied as time-division multiplexed signals to the phase-locked oscillator (PLL) 7d, recording light emission waveform generation circuit 11, and frequency comparator 13 in the laser diode driving circuit 2d. In the phase-locked oscillator (PLL) 7d, an emission clock is generated by a phase comparator 8, a low-pass filter (LPF) 9, and a frequency voltage controlled oscillator (VCO) 10 based on the input recording clock, and before the recording starts. In the period (input period of the recording clock), the phase comparator 8 compares the phase of the output of the frequency-voltage controlled oscillator (VCO) 10 with the input recording clock to detect a phase difference. During the recording period, the phase of the output of the frequency voltage controlled oscillator (VCO) 10 is compared with the input recording data to detect a phase difference, and based on this, the two are synchronized. In a period before the start of recording (recording clock input period), the frequency comparator 13 compares the frequency of the output of the frequency voltage controlled oscillator (VCO) 10 with the input recording data, and detects a frequency error. The signal of the frequency error and the signal of the phase difference are input to the adder 15. A frequency-voltage controlled oscillator (VCO) 10 outputs a light-emitting clock synchronized based on the frequency error and the phase difference. When the input period of the recording clock ends, the addition of the frequency error signal from the frequency comparator 13 is stopped by the switch 14. At this time, the sample-and-hold circuit 23 holds the output of the low-pass filter (LPF) 9 to prevent a transient signal based on switching by the switch 14 from being applied to the frequency-voltage controlled oscillator (VCO) 10, and the light emission clock fluctuates. Not to be. At this time, the holding operation of the sample and hold circuit 23 is controlled by the signal formed by the signal forming circuit 20. In the signal forming circuit 20, an output signal is formed by a signal from the delay unit 18 or a control signal for recording timing (recording / reproduction switching signal (R / WB)). In addition to the recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)) from the recording timing signal generation circuit 4 and the phase-locked oscillator (PLL) 7 d And the light emission clock generated in step (1). The recording light emission waveform generation circuit 11 records a recording waveform for driving a laser diode to emit light based on the input recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)), and a light emission clock. Generate and output
[0021]
FIG. 7 is an explanatory diagram of signal waveforms in the laser drive circuit of FIG.
7A shows a recording clock signal waveform, FIG. 7B shows a recording data signal waveform, FIG. 7C shows a recording timing control signal (recording / reproduction switching signal (R / WB)) waveform, and FIG. Is the waveform of the output signal of the delay unit 17, (e) is the waveform of the output signal of the delay unit 18, (f) is the waveform of the output signal of the sample and hold circuit 21, and (g) is the multiplexed signal of the recording clock and the recording data. (H) is a signal waveform of the frequency error between the output of the frequency voltage controlled oscillator (VCO) 10 and the recording clock, and (i) is the phase error and the frequency voltage of the output of the frequency voltage controlled oscillator (VCO) 10 and the recording clock. 3 is a signal waveform of a phase error between an output of a control oscillator (VCO) 10 and recording data. In the pre-recording start period (recording clock input period), synchronization is established so as to eliminate both the frequency error of (h) and the phase error of (i), and in the recording period, the phase error of (i) is eliminated. In this way, synchronization is achieved.
[0022]
Also in the fourth embodiment, since the recording operation is performed by cutting off the supply of the recording clock during the recording period, the recording can be performed in a stable state without the influence of the noise based on the recording clock. In particular, since the frequency comparison is performed during the input period of the recording clock, the pull-in time in the phase locked oscillator (PLL) can be reduced. When the input of the output signal from the frequency comparator to the adder 15 is cut off, the sample-and-hold circuit 21 prevents a transient signal from being applied to the frequency-voltage controlled oscillator (VCO) 10 and suppresses the fluctuation of the emission clock. It can be suppressed.
The configuration for preventing the transient signal from being applied to the frequency voltage controlled oscillator (VCO) 10 by the sample and hold circuit 21 can be added to the configuration of the third embodiment.
[0023]
FIGS. 8 and 9 are explanatory diagrams of a fifth embodiment of the present invention. FIG. 8 is a configuration diagram of a laser drive circuit, and FIG. 9 is an explanatory diagram of a signal waveform thereof.
The fifth embodiment is an example in which both the phase comparison and the frequency comparison are performed during the input period of the recording clock using the divided recording clock.
In FIG. 8, 1b is a signal processing circuit, 2e is a laser diode driving circuit for driving a laser diode to emit light, and 3 is a recording clock as a first clock generating means for generating a recording clock as a reference of a recording operation. The generating circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the recording clock, and outputs the recording timing signal as a control signal generating means. A recording data modulating circuit as recording data generating means for modulating and outputting recording data based on the data, a frequency dividing circuit 22 as a first frequency dividing means for dividing the recording clock, and a recording timing control signal (6) Based on the recording / reproduction switching signal (R / WB), the signal from the signal processing circuit 1b to the laser diode driving circuit 2e is The switch 7e serves as a switching means for switching the supply timing of the recording clock and the supply timing of the recording data in a time-division manner, and a switch 7e serves as a second clock generation means for generating an emission clock for determining the emission timing of the laser diode. Is a phase comparator that constitutes a phase locked oscillator (PLL) 7e, 9 is a low-pass filter (LPF), and 10 is a frequency voltage controlled oscillator (VCO) as a variable frequency oscillating means. ), 21 are frequency divider circuits as second frequency dividing means for dividing the output of the frequency voltage controlled oscillator (VCO) 10, and 11 is the recording timing control signal (recording / reproduction switching signal (R / WB) ), The above-described recording data and the above-mentioned emission clock, a waveform generating means for generating a recording waveform for causing the laser diode to emit light. A recording light emission waveform generating circuit, 12 is a laser diode, and 13 is a frequency comparator which compares the frequency of the input divided recording clock with the output of the frequency voltage controlled oscillator (VCO) 10 to detect a frequency error , 14 are switched based on the recording timing control signal (recording / reproduction switching signal (R / WB)) so that the frequency comparison is performed during the period in which the recording clock (divided recording clock) is input. Is an adder. The dividing ratio of the dividing circuit 22 and the dividing ratio of the dividing circuit 21 are made equal. Further, the phase comparator 8 has a configuration capable of comparing phases even when the phase comparison timing is discontinuous.
[0024]
In the above configuration, the recording clock generated by the recording clock generation circuit 3 is input to the recording timing signal generation circuit 4, the recording data modulation circuit 5, and the frequency dividing circuit 22. The recording timing signal generation circuit 4 generates a recording timing control signal (recording / reproduction switching signal (R / WB)) based on the input recording clock, and the recording data modulation circuit generates recording data based on the input recording clock. And the frequency dividing circuit 22 divides the frequency of the recording clock. The divided recording clock, the generated recording timing control signal (recording / reproduction switching signal (R / WB)), and the modulated recording data are input to the switch 6. In the switch 6, the supply timing of the input divided clock and the recording data to the laser diode drive circuit 2e and the frequency comparator 13 side is controlled by a recording timing control signal (recording / reproduction switching signal (R / WB)) to perform switching in a time division manner. The switched divided recording clock and recording data are transmitted on the same signal line as time-division multiplexed signals, and the phase-locked oscillator (PLL) 7e and the recording emission waveform generation circuit 11 in the laser diode driving circuit 2e are transmitted. Is supplied to the frequency comparator 13. In the phase-locked oscillator (PLL) 7e, an emission clock is generated by a phase comparator 8, a low-pass filter (LPF) 9, and a frequency-voltage controlled oscillator (VCO) 10 based on the input recording clock, and before the recording starts. , Ie, during the input period of the divided recording clock, in the phase comparator 8, the phase of the signal obtained by dividing the output of the frequency voltage controlled oscillator (VCO) 10 by the frequency dividing circuit 21 and the divided recording clock After comparing and detecting the phase difference, the two are synchronized based on the phase difference. During the recording period, the phase of the signal obtained by dividing the output of the frequency-voltage controlled oscillator (VCO) 10 and the input recording data are compared. The phase difference is detected by comparison, and based on this, the two are synchronized. In the period before the start of recording, that is, in the input period of the divided recording clock, the frequency comparator 13 compares the frequency of the signal obtained by dividing the output of the frequency voltage controlled oscillator (VCO) 10 with the inputted recording data. Then, a frequency error is detected. The signal of the frequency error and the signal of the phase difference are input to the adder 15. A frequency-voltage controlled oscillator (VCO) 10 outputs a light-emitting clock synchronized based on the frequency error and the phase difference. In addition to the recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)) from the recording timing signal generation circuit 4 and the phase-locked oscillator (PLL) 7 e And the light emission clock generated in step (1). The recording light emission waveform generation circuit 11 generates a recording waveform for driving a laser diode to emit light based on the input recording data, a recording timing control signal (recording / reproduction switching signal (R / WB)), and a light emission clock. Generate and output.
[0025]
FIG. 9 is an explanatory diagram of signal waveforms in the laser drive circuit of FIG.
9A shows a recording clock signal waveform, FIG. 9B shows a recording data signal waveform, FIG. 9C shows a recording timing control signal (recording / reproduction switching signal (R / WB)) waveform, and FIG. Is a multiplexed signal waveform of a divided recording clock and recording data, (e) is a signal waveform of a frequency error between a signal obtained by dividing the output of the frequency voltage controlled oscillator (VCO) 10 and a divided recording clock, ( f) is a phase error between the signal obtained by dividing the output of the frequency voltage controlled oscillator (VCO) 10 and the divided recording clock, and the difference between the signal obtained by dividing the output of the frequency voltage controlled oscillator (VCO) 10 and the recording data. It is a signal waveform of a phase error. In the pre-recording start period (input period of the divided recording clock), synchronization is established so as to eliminate both the phase error of (e) and the frequency error of (f). Synchronization is achieved so as to eliminate errors.
[0026]
According to the fifth embodiment as well, the supply of the recording clock is cut off during the recording period, so that the effect of noise based on the recording clock can be eliminated and stable recording can be performed. In particular, since the clock frequency transmitted from the signal processing circuit 1b to the laser diode driving circuit 2e can be lower than the emission clock, it is suitable for high-speed recording. Further, since the frequency comparator is provided, the pull-in time in the phase locked oscillator (PLL) can be reduced.
[0027]
Each switch in the first to fifth embodiments is configured by a logic circuit.
The configuration using the divided recording clock and the signal obtained by dividing the output of the frequency voltage controlled oscillator (VCO) is described in, for example, the first embodiment, the third embodiment, or the fourth embodiment. The present invention can also be applied to the above configuration.
[0028]
【The invention's effect】
According to the present invention, it is possible to perform stable recording in an optical disk device without the influence of noise based on a recording clock.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of a laser drive circuit according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of signal waveforms of the laser drive circuit of FIG. 1;
FIG. 3 is a diagram illustrating a configuration example of a laser drive circuit according to a second embodiment of the present invention;
FIG. 4 is an explanatory diagram of signal waveforms of the laser drive circuit of FIG. 3;
FIG. 5 is a diagram showing a third embodiment of the present invention.
FIG. 6 is a diagram illustrating a configuration example of a laser driving circuit according to a fourth embodiment of the present invention.
7 is an explanatory diagram of signal waveforms of the laser drive circuit of FIG.
FIG. 8 is a diagram illustrating a configuration example of a laser driving circuit according to a fifth embodiment of the present invention.
9 is an explanatory diagram of signal waveforms of the laser drive circuit of FIG.
FIG. 10 is a diagram illustrating a configuration example of a conventional laser drive circuit.
[Explanation of symbols]
1a, 1b, 1c: signal processing circuit, 2a, 2b, 2c, 2d, 2e, 2 ': laser diode driving circuit, 3: recording clock generation circuit, 4: recording timing signal generation circuit, 5: recording data modulation circuit, 6, 14, 16: switch, 7a, 7b, 7c, 7d, 7e: phase-locked oscillator (PLL), 8: phase comparator, 9: low-pass filter (LPF), 10: frequency-voltage controlled oscillator (VCO) Reference numeral 11: a recording light emission waveform generation circuit; 12, a laser diode; 13, a frequency comparator; 15, an adder; 17, 18, a delay unit; 21, 22, a frequency dividing circuit;

Claims

A laser drive circuit capable of driving a laser diode and recording data on an optical disc,
First means for generating recording data, generating a recording clock serving as a reference for a recording operation, and generating a recording timing control signal based on the recording clock;
Second means for generating an emission clock for determining emission timing of the laser diode based on at least the recording clock;
Third means for generating a recording waveform of laser emission based on the recording data and the emission clock;
A fourth method in which the supply timing of the recording data to the third means and the supply timing of the recording clock to the second means are time-divisionally switched based on the recording timing control signal of the first means. Means,
A laser driving circuit, wherein during recording, the recording clock and the recording data are supplied in a time sharing manner from the first means to the second means and the third means, respectively. .

A laser drive circuit capable of driving a laser diode and recording data on an optical disc,
Recording data generating means for generating recording data;
First clock generation means for generating a recording clock serving as a reference for a recording operation;
Control signal generating means for generating a recording timing control signal based on the recording clock;
Second clock generation means for generating an emission clock for determining emission timing of the laser diode based on at least the recording clock;
Waveform generating means for generating a recording waveform of laser emission based on the recording data and the emission clock,
Switching means for switching the supply timing of the recording data to the waveform generating means and the supply timing of the recording clock to the second clock generating means in a time division manner based on the recording timing control signal;
A laser driving circuit characterized in that during recording, the recording clock and the recording data can be supplied to the second clock generating means and the waveform generating means in a time-division manner through the same signal line, respectively. .

The second clock generating means receives a signal obtained by time-divisionally superimposing the recording clock and the recording data, and includes a variable frequency oscillating means. During the input period of the recording clock, the recording clock and the oscillation means The frequency error signal with the output or the frequency error signal and the phase error signal are selected and added, and during the recording data input period, the phase error signal between the recording data and the output of the oscillation means is selected and added. 3. The laser drive circuit according to claim 2, wherein the laser drive circuit is configured to generate a light emission clock synchronized with the recording clock.

The second clock generation means receives a signal obtained by time-divisionally superimposing the recording clock and the recording data, and includes a variable frequency oscillating means. During the recording clock input period, the recording clock and the oscillating means A frequency error signal with the output is selected and added. During the recording data input period, a phase error signal between the recording data and the output of the oscillating means is selected and added. 3. The laser driving circuit according to claim 2, wherein the laser driving circuit is configured to generate a light emission clock synchronized with the recording clock.

A laser drive circuit capable of driving a laser diode and recording data on an optical disc,
Recording data generating means for generating recording data;
First clock generation means for generating a recording clock serving as a reference for a recording operation;
First frequency dividing means for dividing the generated recording clock,
Control signal generating means for generating a recording timing control signal based on the recording clock;
Frequency oscillating means, and second frequency dividing means for dividing the output of the oscillating means. The frequency-divided output of the oscillating means, the divided recording clock, and the frequency of the oscillating means. Second clock generation means for generating a light emission clock for determining a light emission timing of the laser diode based on the circulated output and the recording data;
Waveform generating means for generating a recording waveform of laser emission based on the recording data and the emission clock,
Switching means for switching the supply timing of the recording data to the waveform generating means and the supply timing of the divided recording clock to the second clock generating means in a time-division manner based on the recording timing control signal;
During recording, the divided clock signal and the recording data are supplied to the second clock generation means and the waveform generation means in a time-division manner through the same signal line, respectively, and the second clock In the generation unit, during the input period of the divided recording clock, a frequency error signal between the divided recording clock and the divided output of the oscillating unit is selected and added, and the input period of the recording data is selected. A laser drive circuit characterized in that a phase error signal between the recording data and the frequency-divided output of the oscillation means is selected and added to generate an emission clock synchronized with the recording clock.

6. A configuration according to claim 5, wherein the frequency division value of the recording clock in the first frequency division means is equal to the frequency division value of the output of the variable frequency oscillation means in the second frequency division means. Laser drive circuit.

An optical disk device having a configuration capable of recording data on an optical disk by a laser,
First means for generating recording data, a recording clock serving as a reference for a recording operation, and a recording timing control signal based on the recording clock, and determining a light emission timing of the laser diode based on at least the recording clock. Means for generating a light emission clock for generating the laser light, a third means for generating a recording waveform of laser emission based on the recording data and the light emission clock, and a timing of supplying the recording data to the third means. And fourth means for switching the supply timing of the recording clock to the second means in a time-division manner based on the control signal for recording timing of the first means. A laser driving circuit for supplying the recording data in a time-sharing manner from the first means to the second means and the third means, respectively;
A laser diode driven by the laser drive circuit,
An optical system that includes an objective lens and irradiates the recording surface of the optical disc with laser light from the laser diode;
A pickup moving mechanism that moves a pickup including at least the laser diode and the optical system,
A spindle motor for rotating an optical disc;
A motor drive circuit for driving the spindle motor;
An optical disc device characterized by comprising:

An optical disk device having a configuration capable of recording data on an optical disk by a laser,
Recording data generating means for generating recording data, first clock generating means for generating a recording clock that is a reference for a recording operation, control signal generating means for generating a recording timing control signal based on the recording clock, Second clock generation means for generating an emission clock for determining the emission timing of the laser diode based on the recording clock; and waveform generation for generating a recording waveform of laser emission based on the recording data and the emission clock. Means for switching the supply timing of the recording data to the waveform generating means and the supply timing of the recording clock to the second clock generating means in a time-division manner based on the control signal for recording timing. During recording, the recording clock and the recording data are transmitted through the same signal line. In time division, a laser driving circuit respectively and can be supplied to the said second clock generating means and said waveform generating means,
A laser diode driven by the laser drive circuit,
An optical system that includes an objective lens and irradiates the recording surface of the optical disc with laser light from the laser diode;
A pickup moving mechanism that moves a pickup including at least the laser diode and the optical system,
A spindle motor for rotating an optical disc;
A motor drive circuit for driving the spindle motor;
An optical disc device characterized by comprising:

An optical disk device having a configuration capable of recording data on an optical disk by a laser,
Recording data generating means for generating recording data, first clock generating means for generating a recording clock serving as a reference for a recording operation, first frequency dividing means for dividing the generated recording clock, and recording Control signal generating means for generating a recording timing control signal based on a clock; variable frequency oscillating means; and second frequency dividing means for dividing the output of the oscillating means. Second clock generating means for generating an emission clock for determining the emission timing of the laser diode based on the divided recording clock, the divided output of the oscillating means, and the recording data; and A waveform generating means for generating a recording waveform of laser emission based on the data and the emission clock; and a timing of supplying the recording data to the waveform generating means. Switching means for switching the supply timing of the divided recording clock to the second clock generating means in a time-division manner based on the recording timing control signal, and when recording, the divided recording clock and the recording Data is supplied to the second clock generation means and the waveform generation means in a time-division manner by the same signal line, and the second clock generation means performs the input period of the divided recording clock, A frequency error signal between the frequency-divided recording clock and the frequency-divided output of the oscillating means is selected and added, and during the recording data input period, the frequency of the recording data is divided by the frequency-divided output of the oscillating means. A laser drive circuit that selects and adds the phase error signals of the above and generates a light emission clock synchronized with the recording clock;
A laser diode driven by the laser drive circuit,
An optical system that includes an objective lens and irradiates the recording surface of the optical disc with laser light from the laser diode;
A pickup moving mechanism that moves a pickup including at least the laser diode and the optical system,
A spindle motor for rotating an optical disc;
A motor drive circuit for driving the spindle motor;
An optical disc device characterized by comprising:

A laser driving method for driving a laser diode to record data on an optical disc,
Generating recording data, generating a recording clock serving as a reference for the recording operation, and generating a recording timing control signal based on the recording clock;
Supplying the recording data supply timing and the recording clock supply timing in a time division manner based on the recording timing control signal;
Based on at least the supplied recording clock, generating a light emission clock for determining the light emission timing of the laser diode,
Generating a recording waveform of laser emission based on the recording data and the emission clock;
Supplying the generated recording waveform to a laser diode;
And driving the laser diode through the method.

A laser driving method for driving a laser diode to record data on an optical disc,
Generating recording data, generating a recording clock serving as a reference for a recording operation, generating a recording timing control signal based on the recording clock, and dividing the recording clock;
Supplying the recording data supply timing and the divided recording clock supply timing in a time division manner based on the recording timing control signal;
Based on the divided recording clock and the recording data, generating an emission clock for determining the emission timing of the laser diode,
Generating a recording waveform of laser emission based on the recording data and the emission clock;
Supplying the generated recording waveform to a laser diode;
And driving the laser diode through the method.