JPS6164621U - - Google Patents
Info
- Publication number
- JPS6164621U JPS6164621U JP14837784U JP14837784U JPS6164621U JP S6164621 U JPS6164621 U JP S6164621U JP 14837784 U JP14837784 U JP 14837784U JP 14837784 U JP14837784 U JP 14837784U JP S6164621 U JPS6164621 U JP S6164621U
- Authority
- JP
- Japan
- Prior art keywords
- focus
- signal
- circuit
- zero
- error signal
- 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 4
- 238000010586 diagram Methods 0.000 description 2
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
Landscapes
- Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
Description
第１図は本考案回路の一実施例の系統図、第２
図は従来技術の説明に供する図、第３図及び第４
図はそれぞれ本考案の説明に供するフローチヤー
ト及び波形図をそれぞれ示す。
２…対物レンズ、３…デイスク、５…デイテク
タ、９…フオーカス用アクチユエータ、１０…ジ
ヤストフオーカス検出回路、１１…ＤＦＦ回路、
１２…ゼロクロス検出回路、１３…微分回路、１
４…比較器、１５…駆動信号発生回路、Ｓｗ１…
アナログスイツチ、Ｓｆ…フオーカスエラー信号
、Ｖｔｈ…スレシユホールド電圧、Ｓｄ…微分信
号。
Fig. 1 is a system diagram of one embodiment of the circuit of the present invention;
The figures are for explaining the prior art, Figures 3 and 4.
The figures respectively show a flowchart and a waveform diagram for explaining the present invention. 2... Objective lens, 3... Disk, 5... Detector, 9... Focus actuator, 10... Just focus detection circuit, 11... DFF circuit,
12... Zero cross detection circuit, 13... Differential circuit, 1
4...Comparator, 15...Drive signal generation circuit, Sw1 ...
Analog switch, Sf...focus error signal, Vth...threshold voltage, Sd...differential signal.
Claims (1)
フオーカスエラー信号を監視し、このフオーカス
エラー信号からジヤストフオーカス状態を検出し
たときフオーカスサーボンをオン状態にするフオ
ーカスサーボ引込み回路であり、 前記フオーカスエラー信号が所定の一の極性か
ら他の極性に変わる点に応答してゼロクロス信号
を発生するゼロクロス検出回路と、 前記フオーカスエラー信号を微分して微分信号
を形成する微分回路と、 前記ゼロクロス信号が発生されたときに前記微
分信号が所定の条件を満足すればジヤストフオー
カス信号を発生するフオーカス状態判別回路とを
具備し、 前記フオーカスサーボは前記ジヤストフオーカ
ス信号に応答してオン状態にされることを特徴と
するフオーカスサーボ引込み回路。[Claim for Utility Model Registration] A focus error signal is monitored while changing the relative distance between the disk and the objective lens, and when a just focus state is detected from this focus error signal, a focus servo is turned on. A focus servo pull-in circuit, comprising: a zero-cross detection circuit that generates a zero-cross signal in response to a point where the focus error signal changes from one predetermined polarity to another; and a zero-cross detection circuit that differentiates the focus error signal. The focus servo includes a differential circuit that forms a signal, and a focus state determination circuit that generates a just focus signal if the differential signal satisfies a predetermined condition when the zero cross signal is generated, and the focus servo A focus servo pull-in circuit characterized in that it is turned on in response to a just-focus signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14837784U JPS6164621U (en) | 1984-09-29 | 1984-09-29 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14837784U JPS6164621U (en) | 1984-09-29 | 1984-09-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6164621U true JPS6164621U (en) | 1986-05-02 |
Family
ID=30706592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14837784U Pending JPS6164621U (en) | 1984-09-29 | 1984-09-29 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6164621U (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54128707A (en) * | 1978-03-27 | 1979-10-05 | Mca Disco Vision | Focus servo device |
| JPS57113430A (en) * | 1980-12-29 | 1982-07-14 | Matsushita Electric Ind Co Ltd | Focus servo leading-device |
-
1984
- 1984-09-29 JP JP14837784U patent/JPS6164621U/ja active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54128707A (en) * | 1978-03-27 | 1979-10-05 | Mca Disco Vision | Focus servo device |
| JPS57113430A (en) * | 1980-12-29 | 1982-07-14 | Matsushita Electric Ind Co Ltd | Focus servo leading-device |
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