JPH0292819U - - Google Patents

Info

Publication number
JPH0292819U
JPH0292819U JP161489U JP161489U JPH0292819U JP H0292819 U JPH0292819 U JP H0292819U JP 161489 U JP161489 U JP 161489U JP 161489 U JP161489 U JP 161489U JP H0292819 U JPH0292819 U JP H0292819U
Authority
JP
Japan
Prior art keywords
output
time constant
discharge time
hold
setting
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.)
Granted
Application number
JP161489U
Other languages
Japanese (ja)
Other versions
JP2542463Y2 (en
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed filed Critical
Priority to JP1989001614U priority Critical patent/JP2542463Y2/en
Publication of JPH0292819U publication Critical patent/JPH0292819U/ja
Application granted granted Critical
Publication of JP2542463Y2 publication Critical patent/JP2542463Y2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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  • Optical Recording Or Reproduction (AREA)

Description

【図面の簡単な説明】[Brief explanation of drawings]

第１図はこの考案の一実施例の構成を示すブロ
ツク図。第２図はこの考案の一実施例の作用の説
明に供するタイミング図。第３図は従来例の構成
を示すブロツク図。 Ｄ……ダイオード、Ｃ２……コンデンサ、Ｅ…
…加算器、Ｆ……比較器、Ｐ……基準電圧源、Ｒ
２およびＲ３……抵抗、Ｕ１およびＵ３……演算
増幅器。 FIG. 1 is a block diagram showing the configuration of an embodiment of this invention. FIG. 2 is a timing diagram for explaining the operation of one embodiment of this invention. FIG. 3 is a block diagram showing the configuration of a conventional example. D...Diode, C2 ...Capacitor, E...
...Adder, F...Comparator, P...Reference voltage source, R
2 and R 3 ...resistor, U 1 and U 3 ... operational amplifier.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 光デイスクからの反射光を４分割フオトダイオ
ードで受けて電気信号に変換した各出力を加算す
る加算手段と、加算手段の出力を入力とするピー
クホールド手段と、ピークホールド手段の放電時
定数を大きい時定数に設定する放電時定数設定手
段と、ピークホールド手段のホールド出力が基準
電圧レベル以下に低下したことを検出する比較手
段とを備え、比較手段からの検出出力を傷検出出
力としたことを特徴とするデイスクの傷検出回路
。 Adding means for receiving reflected light from the optical disk by a four-split photodiode and converting each output into an electrical signal; peak holding means for inputting the output of the adding means; and a discharge time constant of the peak holding means being increased. A discharge time constant setting means for setting a time constant and a comparison means for detecting that the hold output of the peak hold means has fallen below a reference voltage level are provided, and the detection output from the comparison means is used as the flaw detection output. Features a disc scratch detection circuit.
JP1989001614U 1989-01-12 1989-01-12 Disk scratch detection circuit Expired - Lifetime JP2542463Y2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1989001614U JP2542463Y2 (en) 1989-01-12 1989-01-12 Disk scratch detection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1989001614U JP2542463Y2 (en) 1989-01-12 1989-01-12 Disk scratch detection circuit

Publications (2)

Publication Number Publication Date
JPH0292819U true JPH0292819U (en) 1990-07-24
JP2542463Y2 JP2542463Y2 (en) 1997-07-30

Family

ID=31201650

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1989001614U Expired - Lifetime JP2542463Y2 (en) 1989-01-12 1989-01-12 Disk scratch detection circuit

Country Status (1)

Country Link
JP (1) JP2542463Y2 (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6032133A (en) * 1983-08-02 1985-02-19 Toshiba Corp Focus control circuit of optical disk record reproducer
JPS61117737A (en) * 1984-11-13 1986-06-05 Pioneer Electronic Corp Focus servo device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6032133A (en) * 1983-08-02 1985-02-19 Toshiba Corp Focus control circuit of optical disk record reproducer
JPS61117737A (en) * 1984-11-13 1986-06-05 Pioneer Electronic Corp Focus servo device

Also Published As

Publication number Publication date
JP2542463Y2 (en) 1997-07-30

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