JPS63105921U - - Google Patents
Info
- Publication number
- JPS63105921U JPS63105921U JP20091886U JP20091886U JPS63105921U JP S63105921 U JPS63105921 U JP S63105921U JP 20091886 U JP20091886 U JP 20091886U JP 20091886 U JP20091886 U JP 20091886U JP S63105921 U JPS63105921 U JP S63105921U
- Authority
- JP
- Japan
- Prior art keywords
- detection means
- focus
- level
- deviation amount
- servo circuit
- 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
- 238000001514 detection method Methods 0.000 claims description 11
- 230000003287 optical effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 8
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 2
Landscapes
- Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
Description
第１図はこの考案の一実施例によるフオーカス
サーボ回路の要部の構成を示す回路図、第２図は
従来のフオーカスサーボ回路の全体構成を示すブ
ロツク図、第３図は第２図に示す光ピツクアツプ
３内に設けられている光センサＳｅと、第２図に
示すフオーカスエラー信号検出回路５と、レンズ
駆動信号発生回路７の一部を示す図、第４図はフ
オーカスエラー信号ＦＥの理想特性を示す図、第
５図はフオーカスエラー信号ＦＥの実際の特性を
示す図、第６図は歪補正を行つた後のフオーカス
エラー信号ＦＥの特性を示す図、第７図は従来の
レンズ駆動信号発生回路７の構成を示すブロツク
図、第８図は従来のフオーカスサーボ回路におけ
るフイードバツクループのオープンループゲイン
を示す図である。
１……ＣＤ（コンパクトデイスク）、５……フ
オーカスエラー信号検出回路（フオーカスずれ量
検出手段）、５ｆ……可変抵抗（レベル調整手段
）、１１……演算増幅器（レベルクロス検出手段
）、３０，３１……抵抗。
FIG. 1 is a circuit diagram showing the configuration of the main parts of a focus servo circuit according to an embodiment of this invention, FIG. 2 is a block diagram showing the overall configuration of a conventional focus servo circuit, and FIG. A diagram showing a part of the optical sensor Se provided in the optical pickup 3 shown in FIG. 2, the focus error signal detection circuit 5 shown in FIG. 2, and a part of the lens drive signal generation circuit 7, and FIG. FIG. 5 is a diagram showing the ideal characteristics of the signal FE, FIG. 5 is a diagram showing the actual characteristics of the focus error signal FE, FIG. 6 is a diagram showing the characteristics of the focus error signal FE after distortion correction, and FIG. The figure is a block diagram showing the configuration of a conventional lens drive signal generation circuit 7, and FIG. 8 is a diagram showing the open loop gain of the feedback loop in the conventional focus servo circuit. 1...CD (compact disk), 5...Focus error signal detection circuit (focus deviation amount detection means), 5f...variable resistor (level adjustment means), 11...operational amplifier (level cross detection means), 30 , 31...Resistance.
Claims (1)
取装置におけるフオーカスサーボ回路において、
フオーカスずれ量に対応する電圧を出力するフオ
ーカスずれ量検出手段と、前記フオーカスずれ量
検出手段の検出出力が基準レベルを横切つた時こ
れを検出するレベルクロス検出手段と、前記基準
レベルを変化させるレベル調整手段とを具備し、
前記レベルクロス検出手段の検出結果に基づいて
サーボ引き込みを行うことを特徴とするフオーカ
スサーボ回路。 In a focus servo circuit in an optical reading device that reads information recorded on a rotating disk,
a focus deviation amount detection means for outputting a voltage corresponding to the focus deviation amount; a level cross detection means for detecting when the detection output of the focus deviation amount detection means crosses a reference level; and a level cross detection means for changing the reference level. and a level adjustment means,
A focus servo circuit characterized in that servo pull-in is performed based on a detection result of the level cross detection means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20091886U JPS63105921U (en) | 1986-12-27 | 1986-12-27 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20091886U JPS63105921U (en) | 1986-12-27 | 1986-12-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63105921U true JPS63105921U (en) | 1988-07-08 |
Family
ID=31163885
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20091886U Pending JPS63105921U (en) | 1986-12-27 | 1986-12-27 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63105921U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0486223U (en) * | 1990-11-30 | 1992-07-27 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61175936A (en) * | 1985-01-29 | 1986-08-07 | Nec Corp | Focus servo-device in optical information recording device |
-
1986
- 1986-12-27 JP JP20091886U patent/JPS63105921U/ja active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61175936A (en) * | 1985-01-29 | 1986-08-07 | Nec Corp | Focus servo-device in optical information recording device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0486223U (en) * | 1990-11-30 | 1992-07-27 |
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