JPH06243480A - Focus servo pull-in controller - Google Patents
Focus servo pull-in controllerInfo
- Publication number
- JPH06243480A JPH06243480A JP3159293A JP3159293A JPH06243480A JP H06243480 A JPH06243480 A JP H06243480A JP 3159293 A JP3159293 A JP 3159293A JP 3159293 A JP3159293 A JP 3159293A JP H06243480 A JPH06243480 A JP H06243480A
- Authority
- JP
- Japan
- Prior art keywords
- focus
- focus servo
- objective lens
- signal
- lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光学的記録再生装置に
おける光学ピックアップの対物レンズを、その焦点が記
録媒体の表面に合焦する位置であるフォーカスサーボに
引き込むためのフォーカスサーボ引き込み制御装置に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus servo pull-in control device for pulling an objective lens of an optical pickup in an optical recording / reproducing apparatus into a focus servo which is a position where its focus is focused on the surface of a recording medium. .
【０００２】[0002]
【従来の技術】近年、例えば光ディスク装置は映像信号
および音響信号の記録、再生に用いられており、該光デ
ィスク装置には、上述したようなフォーカスサーボ引き
込み制御装置が具備されている。2. Description of the Related Art In recent years, for example, optical disk devices have been used for recording and reproducing video signals and audio signals. The optical disk devices are equipped with the focus servo pull-in control device as described above.
【０００３】以下、図３および図４を参照しながら、前
記光ディスク装置に具備されている従来のフォーカスサ
ーボ引き込み制御装置の一例を説明する。An example of a conventional focus servo pull-in control device provided in the optical disk device will be described below with reference to FIGS. 3 and 4.
【０００４】図３は従来のフォーカスサーボ引き込み制
御装置の構成を示すブロック図、図４は同装置における
フォーカス信号とレンズ駆動指示信号の時間的変化を示
すグラフである。同図において、１は情報信号が記録さ
れた記録媒体、２は記録媒体１を回転させるスピンドル
モータ、３は光ビームを発生する光源、４は光源３から
の光ビームを集光する対物レンズ、５は記録媒体１にて
反射した光の方向を変えるハーフミラー、６は対物レン
ズ４を移動させて焦点位置を変化させるレンズ駆動手
段、７はハーフミラー５を介して記録媒体１からの反射
光を受光する受光素子、８はフォーカス信号を発生する
フォーカス信号発生手段、９は合焦点位置を検出する合
焦点位置検出手段、１０は対物レンズ４の移動方向を反
転させるためのフォーカスサーボ引き込み駆動出力を発
生するフォーカスサーボ引き込み駆動出力発生手段、１
１は対物レンズ４のフォーカス方向位置を示す情報であ
るフォーカス信号レベルを測定する信号レベル測定手
段、１２は対物レンズ４をフォーカスサーボに引き込む
ための信号を出力するフォーカスサーボ系ループフィル
タである。１３は、レンズ駆動手段６への動作指示をフ
ォーカスサーボ引き込み駆動出力発生手段１０が行う状
態とフォーカスサーボ系ループフィルタ１２が行う状態
とに択一的に切り換えるスイッチである。FIG. 3 is a block diagram showing a configuration of a conventional focus servo pull-in control device, and FIG. 4 is a graph showing temporal changes of a focus signal and a lens drive instruction signal in the same device. In the figure, 1 is a recording medium on which an information signal is recorded, 2 is a spindle motor for rotating the recording medium 1, 3 is a light source for generating a light beam, 4 is an objective lens for collecting the light beam from the light source 3, Reference numeral 5 is a half mirror that changes the direction of light reflected by the recording medium 1, 6 is lens driving means that moves the objective lens 4 to change the focus position, and 7 is reflected light from the recording medium 1 via the half mirror 5. A light receiving element for receiving the light, 8 is a focus signal generating means for generating a focus signal, 9 is a focus position detecting means for detecting a focus position, and 10 is a focus servo pull-in drive output for reversing the moving direction of the objective lens 4. Focus servo pull-in drive output generating means for generating
Reference numeral 1 is a signal level measuring means for measuring a focus signal level, which is information indicating the position of the objective lens 4 in the focus direction, and 12 is a focus servo loop filter for outputting a signal for pulling the objective lens 4 into the focus servo. A switch 13 selectively switches between a state in which the focus servo pull-in drive output generating means 10 and a state in which the focus servo loop filter 12 issues an operation instruction to the lens driving means 6.
【０００５】次に、上記構成のフォーカスサーボ引き込
み制御装置の動作を説明する。まず光源３から放射され
た光ビームが、スピンドルモータ２により回転される記
録媒体１に、対物レンズ４により集光され、この記録媒
体１の記録面上に照射されて反射する。この反射光は、
ハーフミラー５により方向を変えられ、受光素子７に照
射される。受光素子７で検出された光量を示す信号は、
フォーカス信号発生手段８によりフォーカス信号に変換
される。Next, the operation of the focus servo pull-in control device having the above structure will be described. First, the light beam emitted from the light source 3 is condensed by the objective lens 4 on the recording medium 1 rotated by the spindle motor 2, and is irradiated onto the recording surface of the recording medium 1 to be reflected. This reflected light is
The direction is changed by the half mirror 5 and the light receiving element 7 is irradiated with the light. The signal indicating the amount of light detected by the light receiving element 7 is
It is converted into a focus signal by the focus signal generating means 8.
【０００６】ここで、対物レンズ４を、その焦点が記録
媒体１の表面に合焦位置であるフォーカスサーボに引き
込む場合においては、レンズ駆動手段６への駆動指示を
フォーカスサーボ引き込み駆動出力発生手段１０が行う
ようにスイッチ１３を図３の状態から一方の接点１４1
側に切り換える。そうすると、フォーカスサーボ引き込
み駆動出力発生手段１０からレンズ駆動手段６へ駆動指
示信号が送られ該駆動指示信号に基づいて対物レンズ４
を一度最下点まで移動させた後、該最下点から引き上げ
ながら、合焦点位置において前記フォーカス信号のレベ
ルを信号レベル測定手段１１により測定し、その測定結
果に基づいてフォーカスサーボ系ループフィルタ１２の
感度調整を行う。これに引き続いて、最上点まで移動し
た対物レンズ４を引き下げながら合焦点位置検出手段９
により合焦点位置の検出を行い、合焦点位置を検出した
ならばスイッチ１３を図３に示す如く他方の接点１４2
側に切り換える。そうするとフォーカスサーボ系ループ
フィルタ１２からレンズ駆動手段６へ駆動指示信号が送
られ、該駆動指示信号に基づいて対物レンズ４を駆動し
て前記フォーカスサーボに引き込むものである。When the objective lens 4 is pulled into the focus servo whose focus is on the surface of the recording medium 1 at the focus position, a drive instruction to the lens driving means 6 is issued to the focus servo pull-in drive output generating means 10. one contact 14 1 of the switch 13 to perform from the state of FIG. 3
Switch to the side. Then, a drive instruction signal is sent from the focus servo pull-in drive output generating means 10 to the lens driving means 6, and the objective lens 4 is sent based on the drive instruction signal.
Is moved to the lowest point once, and then the level of the focus signal is measured by the signal level measuring means 11 at the in-focus position while pulling up from the lowest point, and based on the measurement result, the focus servo system loop filter 12 Adjust the sensitivity of. Following this, the in-focus position detecting means 9 is pulled down while lowering the objective lens 4 that has moved to the highest point.
The in-focus position is detected by means of the switch, and if the in-focus position is detected, the switch 13 is moved to the other contact 14 2 as shown in FIG.
Switch to the side. Then, a drive instruction signal is sent from the focus servo system loop filter 12 to the lens driving means 6, and the objective lens 4 is driven based on the drive instruction signal to pull in the focus servo.
【０００７】以上の動作において、図３のａ点における
フォーカス信号と、ｂ点におけるレンズ駆動指示信号の
時間的変化は図４に示す通りである。In the above operation, the temporal changes of the focus signal at the point a and the lens drive instruction signal at the point b in FIG. 3 are as shown in FIG.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、前記従
来のフォーカスサーボ引き込み制御装置においては、一
度、対物レンズ４を合焦点位置に移動させ、フォーカス
信号のレベルを測定した後、再度、対物レンズ４を初期
位置に戻してから、この対物レンズ４を移動させてフォ
ーカスサーボに引き込むようになっていた。However, in the conventional focus servo pull-in control device, the objective lens 4 is once moved to the in-focus position, the level of the focus signal is measured, and then the objective lens 4 is moved again. After returning to the initial position, the objective lens 4 is moved and pulled into the focus servo.
【０００９】このため、対物レンズ４の移動距離が長く
なり、フォーカス信号レベルの測定後、速やかに対物レ
ンズをフォーカスサーボに引き込むことができないとい
う欠点があった。Therefore, there is a drawback that the moving distance of the objective lens 4 becomes long and the objective lens cannot be quickly pulled into the focus servo after measuring the focus signal level.
【００１０】本発明は、上記事情に鑑みてなされたもの
で、フォーカス信号レベルの測定後、速やかに、対物レ
ンズをフォーカスサーボに引き込むことができるフォー
カスサーボ引き込み制御装置を提供することを目的とす
る。The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a focus servo pull-in control device capable of quickly pulling the objective lens into the focus servo after measuring the focus signal level. .
【００１１】[0011]
【課題を解決するための手段】上記目的を達成するた
め、本発明のフォーカスサーボ引き込み制御装置は、フ
ォーカス信号レベルの測定が完了したことを検出する測
定完了検出手段と、該測定完了検出手段の検出信号に基
づいて対物レンズをフォーカスサーボに引き込むべく対
物レンズの移動方向を反転させる移動方向反転手段とを
具備したことを特徴とするものである。In order to achieve the above object, the focus servo pull-in control device of the present invention comprises a measurement completion detecting means for detecting the completion of the measurement of the focus signal level, and a measurement completion detecting means of the measurement completion detecting means. And a moving direction reversing means for reversing the moving direction of the objective lens in order to draw the objective lens into the focus servo based on the detection signal.
【００１２】[0012]
【作用】本発明は、上記構成によって、まず、フォーカ
ス信号レベルの測定を完了したことを測定完了検出手段
が検出すると、その検出信号に基づいて、移動方向反転
手段が対物レンズの移動方向を反転させ、この対物レン
ズを、その焦点が記録媒体の表面に合焦する位置である
フォーカスサーボに引き込む。これにより、フォーカス
サーボ引き込み完了までの対物レンズの移動距離が最小
限となり、対物レンズを、フォーカス信号レベルの測定
後、速やかにフォーカスサーボに引き込むことができ
る。According to the present invention, when the measurement completion detecting means detects that the focus signal level measurement is completed, the moving direction reversing means reverses the moving direction of the objective lens based on the detection signal. Then, the objective lens is pulled into the focus servo, which is the position where the focal point of the objective lens is focused on the surface of the recording medium. This minimizes the moving distance of the objective lens until the focus servo pull-in is completed, and the objective lens can be pulled into the focus servo promptly after measuring the focus signal level.
【００１３】[0013]
【実施例】以下、本発明のフォーカスサーボ引き込み制
御装置の一実施例について、図１及び図２を参照しなが
ら説明する。図１は本発明の一実施例に係るフォーカス
サーボ引き込み制御装置の構成を示すブロック図、図２
は同装置におけるフォーカス信号とレンズ駆動指示信号
の時間的変化を示すグラフである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the focus servo pull-in control device of the present invention will be described below with reference to FIGS. 1 is a block diagram showing the configuration of a focus servo pull-in control device according to an embodiment of the present invention, FIG.
3 is a graph showing temporal changes of a focus signal and a lens drive instruction signal in the same device.
【００１４】１は情報信号が記録された記録媒体、２は
記録媒体１を回転させるスピンドルモータ、３は光ビー
ムを発生する光源、４は光源３からの光ビームを集光す
る対物レンズ、５は記録媒体１にて反射した光の方向を
変えるハーフミラー、６は対物レンズ４を移動させて焦
点位置を変化させるレンズ駆動手段、７はハーフミラー
５を介して記録媒体１からの反射光を受光する受光素
子、８はフォーカス信号を発生するフォーカス信号発生
手段、９は合焦点位置を検出する合焦点位置検出手段、
１０は対物レンズ４の移動方向を反転させるためのフォ
ーカスサーボ引き込み駆動出力を発生するフォーカスサ
ーボ引き込み駆動出力発生手段、１１は対物レンズ４の
フォーカス方向位置を示す情報であるフォーカス信号レ
ベルを測定する信号レベル測定手段、１２は対物レンズ
４をフォーカスサーボに引き込むための信号を出力する
フォーカスサーボ系ループフィルタである。１３は、レ
ンズ駆動手段６への動作指示をフォーカスサーボ引き込
み駆動出力発生手段１０が行う状態とフォーカスサーボ
系ループフィルタ１２が行う状態とに択一的に切り換え
るスイッチである。Reference numeral 1 is a recording medium on which an information signal is recorded, 2 is a spindle motor for rotating the recording medium 1, 3 is a light source for generating a light beam, 4 is an objective lens for focusing the light beam from the light source 3, 5 Is a half mirror that changes the direction of the light reflected by the recording medium 1, 6 is a lens driving unit that moves the objective lens 4 to change the focus position, and 7 is the half mirror 5 that reflects the reflected light from the recording medium 1. A light receiving element for receiving light, 8 is a focus signal generating means for generating a focus signal, 9 is a focus position detecting means for detecting a focus position,
Reference numeral 10 is a focus servo pull-in drive output generating means for generating a focus servo pull-in drive output for reversing the moving direction of the objective lens 4, and 11 is a signal for measuring the focus signal level, which is information indicating the focus direction position of the objective lens 4. The level measuring means 12 is a focus servo loop filter that outputs a signal for pulling the objective lens 4 into the focus servo. A switch 13 selectively switches between a state in which the focus servo pull-in drive output generating means 10 and a state in which the focus servo loop filter 12 issues an operation instruction to the lens driving means 6.
【００１５】また、信号レベル測定手段１１と合焦点位
置検出手段９との間には、信号レベル測定手段１１によ
るフォーカス信号レベルの測定が完了したことを検出す
る測定完了検出手段１５が設けてあり、フォーカスサー
ボ引き込み駆動出力発生手段１０とスイッチ１３の一方
の接点１４1との間には、フォーカスサーボ引き込み駆
動出力の方向を反転させる駆動出力方向反転手段１６が
設けてある。Further, between the signal level measuring means 11 and the focus position detecting means 9, there is provided a measurement completion detecting means 15 for detecting that the measurement of the focus signal level by the signal level measuring means 11 is completed. , between one of the contact 14 1 of the focus servo pull-in drive output generating means 10 and the switch 13, the drive output direction reversing means 16 which reverses the direction of the focus servo pull-in drive output is provided.
【００１６】次に上記構成のフォーカスサーボ引き込み
制御装置の動作を説明する。まず、光源３から放射され
た光ビームが、スピンドルモータ２により回転される記
録媒体１に、対物レンズ４により集光され、この記録媒
体１の記録面上に照射されて反射する。この反射光は、
ハーフミラー５により方向を変えられ、受光素子７に照
射される。この受光素子７で検出された光量を示す信号
は、フォーカス信号発生手段８によりフォーカス信号に
変換される。Next, the operation of the focus servo pull-in control device having the above structure will be described. First, the light beam emitted from the light source 3 is condensed on the recording medium 1 rotated by the spindle motor 2 by the objective lens 4, and is irradiated onto the recording surface of the recording medium 1 to be reflected. This reflected light is
The direction is changed by the half mirror 5 and the light receiving element 7 is irradiated with the light. A signal indicating the amount of light detected by the light receiving element 7 is converted into a focus signal by the focus signal generating means 8.
【００１７】ここで、対物レンズ４を、前記フォーカス
サーボに引き込む場合においては、レンズ駆動手段６へ
の駆動指示をフォーカスサーボ引き込み駆動出力発生手
段１０、１１が行うようにスイッチ１３を図１の状態か
ら一方の接点１４a側に切り換える。そうすると、フォー
カスサーボ引き込み駆動出力発生手段１０からレンズ駆
動手段６への駆動指示信号が送られ、該駆動指示信号に
基づいて対物レンズ４を一度最下点まで移動させた後、
該最下点から引き上げながら、全焦点位置において前記
フォーカス信号のレベルを信号レベル測定手段１１によ
り測定し、その測定結果に基づいてフォーカスサーボ系
ループフィルタ１２の感度調整を行う。これに引き続い
て、測定完了検出手段１５により前記フォーカス信号レ
ベルの測定完了を検出したならば、駆動出力反転手段１
６により、対物レンズ４の移動方向を反転させ、この対
物レンズ４を引き下げながら合焦点位置放出手段９によ
り合焦点位置の検出を行い、合焦点位置を検出したなら
ばスイッチ１３を図１に示す如く他方の接点１４b側に
切り換える。そうするとフォーカスサーボ系ルループフ
ィルタ１２からレンズ駆動手段６へ駆動指示信号が送ら
れ、該駆動指示信号に基づいて、対物レンズ４を駆動し
て前記フォーカスサーボに引き込むものである。Here, when the objective lens 4 is pulled into the focus servo, the switch 13 is set to the state shown in FIG. 1 so that the focus servo pull-in drive output generating means 10 and 11 give a drive instruction to the lens driving means 6. From one contact 14 a side. Then, a drive instruction signal is sent from the focus servo pull-in drive output generating means 10 to the lens driving means 6, and the objective lens 4 is once moved to the lowest point based on the drive instruction signal.
While raising from the lowest point, the level of the focus signal is measured by the signal level measuring means 11 at all focal positions, and the sensitivity of the focus servo system loop filter 12 is adjusted based on the measurement result. Subsequent to this, if the measurement completion detecting means 15 detects the measurement completion of the focus signal level, the drive output inverting means 1
6, the moving direction of the objective lens 4 is reversed, the focusing point emitting means 9 detects the focusing point while pulling down the objective lens 4, and if the focusing point is detected, the switch 13 is shown in FIG. As described above, the contact is switched to the other contact 14 b side. Then, a drive instruction signal is sent from the focus servo system loop filter 12 to the lens drive means 6, and based on the drive instruction signal, the objective lens 4 is driven and pulled into the focus servo.
【００１８】以上の動作において、図１のａ点における
フォーカス信号と、ｂ点におけるレンズ駆動指示信号の
時間的変化は図２に示す通りである。該図２にて明確な
ように、本発明装置の方が従来装置に比して対物レンズ
４の移動距離が短くなって、フォーカス信号レベルの測
定完了後、速やかに対物レンズをフォーカスサーボに引
き込むことができるものである。In the above operation, the temporal changes of the focus signal at point a and the lens drive instruction signal at point b in FIG. 1 are as shown in FIG. As is clear from FIG. 2, in the device of the present invention, the moving distance of the objective lens 4 is shorter than that of the conventional device, and the objective lens is quickly pulled into the focus servo after the measurement of the focus signal level is completed. Is something that can be done.
【００１９】[0019]
【発明の効果】以上のように、本発明のフォーカスサー
ボ引き込み制御装置によれば、対物レンズの移動距離が
最小限で、フォーカス信号の変動の調整と、対物レンズ
のフォーカスサーボへの引き込みを行うことが可能であ
り、フォーカス信号レベルの測定完了から対物レンズの
フォーカスサーボへの引き込み完了までの時間を従来に
比して３０％程度短縮できる効果を奏する。As described above, according to the focus servo pull-in control device of the present invention, the movement distance of the objective lens is minimized, and the fluctuation of the focus signal is adjusted and the objective lens is pulled into the focus servo. Therefore, there is an effect that the time from the completion of the measurement of the focus signal level to the completion of the drawing of the objective lens into the focus servo can be shortened by about 30% as compared with the conventional case.
【図１】本発明の一実施例に係るフォーカスサーボ引き
込み制御装置の概略構成を示すブロック図FIG. 1 is a block diagram showing a schematic configuration of a focus servo pull-in control device according to an embodiment of the present invention.
【図２】同装置におけるフォーカス信号とレンズ駆動指
示信号の時間的変化を示すグラフFIG. 2 is a graph showing temporal changes of a focus signal and a lens drive instruction signal in the same device.
【図３】従来のフォーカスサーボ引き込み制御装置の概
略構成を示すブロック図FIG. 3 is a block diagram showing a schematic configuration of a conventional focus servo pull-in control device.
【図４】同装置従来におけるフォーカス信号とレンズ駆
動指示信号の時間的変化を示すグラフFIG. 4 is a graph showing a temporal change of a focus signal and a lens drive instruction signal in the same apparatus in the related art.
【符号の説明】 １ 記録媒体 ４ 対物レンズ １０ フォーカスサーボ引き込み駆動出力発生手段 １６ フォーカスサーボ引き込み駆動出力方向反転手段
（移動方向反転手段） １１ フォーカス信号のレベル測定手段 １５ 測定完了検出手段[Explanation of reference numerals] 1 recording medium 4 objective lens 10 focus servo pull-in drive output generating means 16 focus servo pull-in drive output direction reversing means (moving direction reversing means) 11 focus signal level measuring means 15 measurement completion detecting means
Claims (1)
アップの対物レンズを、その焦点が記録媒体の表面に合
焦する位置であるフォーカスサーボに引き込むためのフ
ォーカスサーボ引き込み制御装置であって、前記対物レ
ンズのフォーカス方向位置を示す情報であるフォーカス
信号レベルの測定が完了したことを検出する測定完了検
出手段と、該測定完了検出手段の検出信号に基づいて前
記対物レンズを前記フォーカスサーボに引き込むべく前
記対物レンズの移動方向を反転させる移動方向反転手段
とを具備したことを特徴とするフォーカスサーボ引き込
み制御装置。1. A focus servo pull-in control device for pulling an objective lens of an optical pickup in an optical recording / reproducing apparatus into a focus servo, which is a position where its focus is focused on the surface of a recording medium. Measurement completion detecting means for detecting that the measurement of the focus signal level, which is information indicating the focus direction position of the object, is completed, and the objective for pulling the objective lens into the focus servo based on the detection signal of the measurement completion detecting means. A focus servo pull-in control device, comprising: a moving direction reversing means for reversing a moving direction of a lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3159293A JPH06243480A (en) | 1993-02-22 | 1993-02-22 | Focus servo pull-in controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3159293A JPH06243480A (en) | 1993-02-22 | 1993-02-22 | Focus servo pull-in controller |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06243480A true JPH06243480A (en) | 1994-09-02 |
Family
ID=12335466
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3159293A Pending JPH06243480A (en) | 1993-02-22 | 1993-02-22 | Focus servo pull-in controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06243480A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005071398A (en) * | 2003-08-22 | 2005-03-17 | Pioneer Electronic Corp | Optical pickup device and optical recording medium reproducing device |
-
1993
- 1993-02-22 JP JP3159293A patent/JPH06243480A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005071398A (en) * | 2003-08-22 | 2005-03-17 | Pioneer Electronic Corp | Optical pickup device and optical recording medium reproducing device |
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