JPS6444453U - - Google Patents
Info
- Publication number
- JPS6444453U JPS6444453U JP14026687U JP14026687U JPS6444453U JP S6444453 U JPS6444453 U JP S6444453U JP 14026687 U JP14026687 U JP 14026687U JP 14026687 U JP14026687 U JP 14026687U JP S6444453 U JPS6444453 U JP S6444453U
- Authority
- JP
- Japan
- Prior art keywords
- reference level
- pass filter
- reproduction signal
- scratch
- measuring device
- 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
- 230000003287 optical effect Effects 0.000 claims description 7
- 238000010586 diagram Methods 0.000 description 4
Landscapes
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Manufacturing Optical Record Carriers (AREA)
Description
第１図は本考案の光デイスクの傷測定装置の一
実施例を示す構成図、第２図は本考案の光デイス
クの傷測定装置の他の実施例を示す構成図、第３
図および第６図は従来の光デイスクの傷測定装置
の一例を示す構成図、第４図、第５図および第７
図はその動作状態を示す波形図である。
１……光デイスク、２……測定ヘツド、３，３
１，３２……比較回路、４……ハイパスフイルタ
、５……ローパスフイルタ、６……基準レベル設
定回路、７……反転増幅器、８……オアゲート。
FIG. 1 is a block diagram showing one embodiment of the optical disk scratch measuring device of the present invention, FIG. 2 is a block diagram showing another embodiment of the optical disk scratch measuring device of the present invention, and FIG.
6 and 6 are block diagrams showing an example of a conventional optical disc scratch measuring device, and FIGS. 4, 5, and 7
The figure is a waveform diagram showing the operating state. 1... Optical disk, 2... Measuring head, 3, 3
1, 32... Comparison circuit, 4... High pass filter, 5... Low pass filter, 6... Reference level setting circuit, 7... Inverting amplifier, 8... OR gate.
Claims (1)
レベルと比較して再生信号のレベル変化から傷の
有無を検出するようにした光デイスクの傷測定装
置において、前記再生信号と基準レベルとを比較
する比較回路の前段に挿入され再生信号の高周波
成分を抽出するハイパスフイルタと、前記再生信
号の直流成分を抽出するローパスフイルタと、こ
のローパスフイルタの出力に応じて前記比較回路
に供給する基準レベルの大きさを変化させる基準
レベル設定回路とを具備してなる光デイスクの傷
測定装置。 In an optical disc scratch measuring device, the reproduction signal proportional to the reflectance of the optical disc is compared with a reference level and the presence or absence of a scratch is detected from a change in the level of the reproduction signal, and the reproduction signal is compared with the reference level. a high-pass filter inserted before the comparator circuit to extract high-frequency components of the reproduced signal; a low-pass filter to extract the DC component of the reproduced signal; and a reference level supplied to the comparator circuit according to the output of the low-pass filter. An optical disk scratch measuring device comprising a reference level setting circuit for changing the intensity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14026687U JPS6444453U (en) | 1987-09-14 | 1987-09-14 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14026687U JPS6444453U (en) | 1987-09-14 | 1987-09-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6444453U true JPS6444453U (en) | 1989-03-16 |
Family
ID=31404279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14026687U Pending JPS6444453U (en) | 1987-09-14 | 1987-09-14 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6444453U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7661187B2 (en) | 2004-12-15 | 2010-02-16 | Hitachi Global Storage Technologies Netherlands B.V. | Manufacturing method for magnetic disk drive |
-
1987
- 1987-09-14 JP JP14026687U patent/JPS6444453U/ja active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7661187B2 (en) | 2004-12-15 | 2010-02-16 | Hitachi Global Storage Technologies Netherlands B.V. | Manufacturing method for magnetic disk drive |
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