JPH0566653B2 - - Google Patents
Info
- Publication number
- JPH0566653B2 JPH0566653B2 JP18052584A JP18052584A JPH0566653B2 JP H0566653 B2 JPH0566653 B2 JP H0566653B2 JP 18052584 A JP18052584 A JP 18052584A JP 18052584 A JP18052584 A JP 18052584A JP H0566653 B2 JPH0566653 B2 JP H0566653B2
- Authority
- JP
- Japan
- Prior art keywords
- sector mark
- circuit
- sector
- output
- waveform
- 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.)
- Expired - Lifetime
Links
- 238000001514 detection method Methods 0.000 claims description 13
- 230000003287 optical effect Effects 0.000 claims description 8
- 230000008929 regeneration Effects 0.000 claims description 8
- 238000011069 regeneration method Methods 0.000 claims description 8
- 238000010586 diagram Methods 0.000 description 7
- 230000003321 amplification Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/005—Reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Optical Recording Or Reproduction (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光デイスクにおける長穴で構成された
特殊マークの検出方式に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting a special mark composed of an elongated hole on an optical disc.
光デイスクへ情報を記録する場合、例えば特願
昭57−51230号明細書（特開昭58−169337号）に
記載されているように、一記録単位毎にその始点
を示すマークを付けることが一般的である。ここ
では記録単位をセクタと呼び、上記マークをセク
タマークと呼ぶことにする。セクタマークはトラ
ツクTR上にデータとして記録される他の孤立穴
Ｐ（第１図Ａ）と区別出来るよう、第１図Ｂに示
すような長穴Ｑの組み合わせで構成される。
When recording information on an optical disk, for example, as described in Japanese Patent Application No. 57-51230 (Japanese Unexamined Patent Publication No. 58-169337), it is possible to attach a mark to each recording unit to indicate its starting point. Common. Here, the recording unit is called a sector, and the mark mentioned above is called a sector mark. The sector mark is composed of a combination of elongated holes Q as shown in FIG. 1B so that it can be distinguished from other isolated holes P (FIG. 1A) recorded as data on the track TR.
従って、長穴Ｑからなるセクタマーク部Ｍと孤
立穴Ｐからなるデータ部とが第２図Ａの如く連続
するトラツク上を光ヘツドで走査すると、光ヘツ
ド出力のセクタマーク波形は第２図Ｂの様にな
る。この場合、高周波特性の良い直流アンプは高
価なため、信号再生系でAC結合の高周波アンプ
を使って増幅を行なうと、増幅後の波形は、第２
図Ｃのように、時間的に変動する成分を持つこと
になる。このため、従来は第３図に示すような回
路を用いて、この変動分を除去してから、セクタ
マークの検出を行なつていた。 Therefore, when the optical head scans a track in which the sector mark part M made up of the elongated hole Q and the data part made up of the isolated hole P are continuous as shown in FIG. 2A, the sector mark waveform of the optical head output is It will look like this. In this case, since DC amplifiers with good high frequency characteristics are expensive, if an AC-coupled high frequency amplifier is used for amplification in the signal regeneration system, the waveform after amplification will be
As shown in Figure C, it has components that vary over time. For this reason, conventionally, a circuit as shown in FIG. 3 has been used to remove this variation before detecting a sector mark.
第３図において、増幅された読取り信号１は、
パルス化回路２で波形成形されてパルスとなり、
パルス幅・位置検出回路３に入力されて長穴の幅
と位置関係からセクタマークが認識され、セクタ
マーク検出信号４が出力される。 In FIG. 3, the amplified read signal 1 is
The waveform is shaped by the pulse generator 2 and becomes a pulse.
The signal is input to a pulse width/position detection circuit 3, a sector mark is recognized from the width and positional relationship of the elongated hole, and a sector mark detection signal 4 is output.
パルス化回路２の中で、微分回路５は読取り信
号１から時間的に変動させる要因である信号の低
周波成分を除去し、第４図の微分波形６を発生す
る。微分波形６は比較器９，１０に入力され、そ
れぞれ基準電圧発生器７および８から発生したプ
ラス側基準電圧およびマイナス側基準電圧と比較
され、RSフリツプフロツプ１１をセツト、リセ
ツトする。この結果、フリツプフロツプ１１から
は、パルス化出力波形１４が得られる。セクタマ
ークは、Ｔ１，Ｔ２の２種類の長穴の組み合わせ
で構成されており、Ｔ１幅長穴検出器１５でＴ１
幅のパルスがあつたことを、Ｔ２幅長穴検出器１
６でＴ２幅のパルスがあつたことが検出される。
これらの検出信号は、遅延回路１７または遅延回
路１８によつて適当な遅延が施され、正常なセク
タマーク検出時には判定回路１９に複数の長穴検
出信号が揃つて入力され、長穴の位置関係の判定
結果によつてセクタマーク検出信号４が出力され
る。 In the pulsing circuit 2, a differentiating circuit 5 removes from the read signal 1 the low frequency component of the signal which is a factor causing temporal fluctuations, and generates a differentiated waveform 6 shown in FIG. Differential waveform 6 is input to comparators 9 and 10, and compared with the positive reference voltage and negative reference voltage generated from reference voltage generators 7 and 8, respectively, to set and reset RS flip-flop 11. As a result, a pulsed output waveform 14 is obtained from the flip-flop 11. The sector mark is composed of a combination of two types of elongated holes, T1 and T2, and the T1 width elongated hole detector 15
The T2 wide oblong hole detector 1 detects that a pulse of
At 6, it is detected that a pulse of T2 width has been applied.
These detection signals are appropriately delayed by a delay circuit 17 or 18, and when a sector mark is detected normally, a plurality of elongated hole detection signals are all input to the determination circuit 19, and the positional relationship of the elongated holes is determined. A sector mark detection signal 4 is output based on the determination result.
第４図において、プラス側基準電圧１２及びマ
イナス側基準電圧１３は、それぞれデイスクノイ
ズ２０に起因する微分波形６上のノイズ２１より
も充分大きくなければならない。 In FIG. 4, the plus side reference voltage 12 and the minus side reference voltage 13 must each be sufficiently larger than the noise 21 on the differential waveform 6 caused by the disk noise 20.
従来方式の問題は、分解能低下時にデータ部Ｄ
でもセクタマークを誤検出することにある。すな
わち、正常時のデータ部は第５図で波形１′に示
す如く、充分な振幅を持つている。この場合に
は、微分波形６′もプラス側基準電圧１２及びマ
イナス側基準電圧１３を越え、パルス化出力波形
１４′は短かいパルス幅の連続となり、セクタマ
ークとして誤検出されることはない。しかしなが
ら、分解能低下時には、データ部波形１″の振幅
が第６図の如く小さくなるため、微分波形６″も
小さくなつて、プラス側基準電圧１２及びマイナ
ス側基準電圧１３とすれすれになる。このため、
パルス化出力１４″が、あたかも長穴の場合のよ
うに、パルス幅が長い部分を発生し、パルスの
幅・位置関係がセクタマークと同一となつた時
に、セクタマークとして誤検出されることがあ
る。これが原因で、低分解能部分の読取り信頼度
が低下する恐れがある。 The problem with the conventional method is that the data section D
However, the problem lies in falsely detecting sector marks. That is, the data portion under normal conditions has sufficient amplitude, as shown by waveform 1' in FIG. In this case, the differential waveform 6' also exceeds the plus side reference voltage 12 and the minus side reference voltage 13, and the pulsed output waveform 14' becomes a series of short pulse widths, so that it will not be erroneously detected as a sector mark. However, when the resolution decreases, the amplitude of the data portion waveform 1'' becomes smaller as shown in FIG. 6, so the differential waveform 6'' also becomes smaller and becomes almost equal to the plus side reference voltage 12 and the minus side reference voltage 13. For this reason,
When the pulsed output 14'' generates a part with a long pulse width, as in the case of a long hole, and the pulse width and positional relationship are the same as the sector mark, it may be mistakenly detected as a sector mark. This may reduce the reliability of reading low-resolution parts.
本発明の目的は、上述したAC結合高周波アン
プ使用による波形の変動を除去し、分解能低下の
影響を受けることなくセクタマークのデイジタル
化信号パルスを取り出せるようにしたセクタマー
ク検出装置を提供することにある。
SUMMARY OF THE INVENTION An object of the present invention is to provide a sector mark detection device that eliminates waveform fluctuations caused by the use of an AC-coupled high-frequency amplifier as described above, and is capable of extracting digitized signal pulses of sector marks without being affected by resolution degradation. be.
セクタマークは各セクタの先頭にあるため、セ
クタマークの直前にはギヤツプと呼ばれる未書込
領域が一定長続いている。この部分は全反射の信
号レベルにあるため、このレベルを基準にすれ
ば、テレビ受像機等で用いられている直流再生回
路を使用して、AC結合高周波アンプで失われた
低周波成分を再生することが可能である。従来方
式では微分回路により、さらに低周波成分を除去
していた為、セクタマーク自身の低周波成分迄除
去しており、その結果、セクタマークとその他の
信号との区別が出来なくなつたものであり、直流
再生回路による低周波成分の再生がこの解決に効
果を発揮する。
Since the sector mark is located at the beginning of each sector, an unwritten area called a gap continues for a certain length immediately before the sector mark. Since this part is at the signal level of total reflection, if we use this level as a reference, we can use the DC regeneration circuit used in television receivers etc. to regenerate the low frequency components lost in the AC coupled high frequency amplifier. It is possible to do so. In the conventional method, a differentiating circuit was used to further remove low frequency components, which also removed the low frequency components of the sector marks themselves, and as a result, it was no longer possible to distinguish between sector marks and other signals. Regeneration of low frequency components using a DC regeneration circuit is effective in solving this problem.
以下、本発明の一実施例を第７図、第８図によ
り説明する。
An embodiment of the present invention will be described below with reference to FIGS. 7 and 8.
第７図は、従来例として説明した第３図のパル
ス化回路２に代る本発明によるセクタマーク検出
装置（パルス化回路）の構成図を示す。増幅され
た読取り信号１（第８図の上段に示す）は直流再
生回路２９に加えられ、直流分が回復される。こ
の結果、直流再生出力波形３０は、第８図の中段
に示す様に、全反射信号レベルに揃えられてピー
クホールド回路３１に入力される。ピークホール
ド回路３１では、セクタマークのピーク電圧３２
を保持し、これを適当な分圧比で分圧して基準電
圧３３を出力する。直流再生出力波形３０は比較
器３４で基準電圧３３と比較され、第８図の下段
に示す様なパルス化出力３５となる。本実施例に
よれば、データ部パルス化出力３６は、分解能に
関係なく、セクタマークより充分小さいパルスと
なり、データ部におけるセクタマーク誤検出を防
止できる。 FIG. 7 shows a configuration diagram of a sector mark detection device (pulsing circuit) according to the present invention, which replaces the pulsing circuit 2 of FIG. 3 described as a conventional example. The amplified read signal 1 (shown in the upper part of FIG. 8) is applied to a DC regeneration circuit 29 to recover the DC component. As a result, the DC reproduction output waveform 30 is input to the peak hold circuit 31 after being adjusted to the total reflection signal level, as shown in the middle part of FIG. In the peak hold circuit 31, the peak voltage 32 of the sector mark
is held and divided at an appropriate voltage division ratio to output a reference voltage 33. The DC reproduction output waveform 30 is compared with a reference voltage 33 by a comparator 34, resulting in a pulsed output 35 as shown in the lower part of FIG. According to this embodiment, the data section pulsed output 36 becomes a pulse that is sufficiently smaller than the sector mark, regardless of the resolution, and erroneous detection of sector marks in the data section can be prevented.
本発明によれば、AC結合高周波アンプ使用に
よる波形の変動を除去し、分解能の低下によるセ
クタマーク誤検出を防止して、高信頼度で低コス
トのセクタマーク検出装置を提供できる。
According to the present invention, it is possible to eliminate waveform fluctuations caused by the use of an AC-coupled high-frequency amplifier, prevent erroneous sector mark detection due to a decrease in resolution, and provide a highly reliable and low-cost sector mark detection device.
第１図Ａ，Ｂはそれぞれ光デイスク上のデータ
とマークの関係を説明するための図、第２図Ａ，
Ｂ，Ｃはセクタマークの長穴と読取り波形の説明
図、第３図は従来のセクタマーク検出回路の説明
図、第４図〜第６図は上記従来回路における信号
波形を説明するための図、第７図は本発明の一実
施例を示す回路図、第８図はその波形説明図であ
る。
２９……直流再生回路、３１……ピークホール
ド回路、３４……電圧比較器。
Figures 1A and 1B are diagrams for explaining the relationship between data and marks on an optical disk, and Figure 2A,
B and C are explanatory diagrams of sector mark slots and read waveforms, FIG. 3 is an explanatory diagram of a conventional sector mark detection circuit, and FIGS. 4 to 6 are diagrams for explaining signal waveforms in the above conventional circuit. , FIG. 7 is a circuit diagram showing one embodiment of the present invention, and FIG. 8 is a waveform explanatory diagram thereof. 29...DC regeneration circuit, 31...Peak hold circuit, 34...Voltage comparator.
Claims (1)
タ情報が孤立穴によつて記録され、未記録部分が
全反射面をもつ光デイスクから前記セクタマーク
情報を検出するセクタマーク検出装置において、
光ヘツドからの出力信号を入力として全反射側の
レベルの揃つた信号として出力する直流再生回路
と、該直流再生回路の出力信号ピーク電圧を保持
し、これを分圧して基準電圧として出力するピー
クホールド回路と、該ピークホールド回路の出力
を基準に上記直流再生回路出力を２値化する電圧
比較器とを有し、該電圧比較器から得られるパル
スのパターンから前記セクタマーク情報を識別す
るようにしたことを特徴とする光デイスクにおけ
るセクタマーク検出装置。1. In a sector mark detection device for detecting sector mark information from an optical disk in which sector mark information is recorded on a track by elongated holes and data information is recorded by isolated holes, and the unrecorded portion has a total reflection surface,
A DC regeneration circuit that receives the output signal from the optical head and outputs it as a signal with a uniform level on the total reflection side, and a peak circuit that holds the output signal peak voltage of the DC regeneration circuit, divides it, and outputs it as a reference voltage. It has a hold circuit and a voltage comparator that binarizes the output of the DC reproduction circuit based on the output of the peak hold circuit, and is configured to identify the sector mark information from the pulse pattern obtained from the voltage comparator. A sector mark detection device for an optical disk, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18052584A JPS6159626A (en) | 1984-08-31 | 1984-08-31 | Mark detection system of optical disc |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18052584A JPS6159626A (en) | 1984-08-31 | 1984-08-31 | Mark detection system of optical disc |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6159626A JPS6159626A (en) | 1986-03-27 |
| JPH0566653B2 true JPH0566653B2 (en) | 1993-09-22 |
Family
ID=16084786
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18052584A Granted JPS6159626A (en) | 1984-08-31 | 1984-08-31 | Mark detection system of optical disc |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6159626A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5355356A (en) * | 1993-05-19 | 1994-10-11 | Maxoptix Corporation | Charge pump for restoring DC in an optical recording read channel |
-
1984
- 1984-08-31 JP JP18052584A patent/JPS6159626A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6159626A (en) | 1986-03-27 |
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