JPH0310170B2 - - Google Patents
Info
- Publication number
- JPH0310170B2 JPH0310170B2 JP58202972A JP20297283A JPH0310170B2 JP H0310170 B2 JPH0310170 B2 JP H0310170B2 JP 58202972 A JP58202972 A JP 58202972A JP 20297283 A JP20297283 A JP 20297283A JP H0310170 B2 JPH0310170 B2 JP H0310170B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- recording
- dropout
- optical recording
- disk
- 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
- 230000003287 optical effect Effects 0.000 claims description 44
- 238000001514 detection method Methods 0.000 claims description 9
- 230000001678 irradiating effect Effects 0.000 claims 1
- 230000007423 decrease Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000002411 adverse Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 230000007547 defect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 230000002950 deficient Effects 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 238000007493 shaping process Methods 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
- G11B7/002—Recording, reproducing or erasing systems characterised by the shape or form of the carrier
- G11B7/0037—Recording, reproducing or erasing systems characterised by the shape or form of the carrier with discs
- G11B7/00375—Recording, reproducing or erasing systems characterised by the shape or form of the carrier with discs arrangements for detection of physical defects, e.g. of recording layer
-
- 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
- G11B27/36—Monitoring, i.e. supervising the progress of recording or reproducing
Landscapes
- Optical Recording Or Reproduction (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は光学的に記録再生できるデイスクに情
報を記録しこのデイスクから記録した情報を再生
するための光学的情報記録再生装置に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical information recording and reproducing apparatus for recording information on an optically recordable and reproducing disk and for reproducing the recorded information from the disk.
従来例の構成とその問題点
レーザー等の光を直径1μm以下の光に絞つて光
記録デイスクに高密度で信号を記録再生すること
は、ビデオデイスクの原盤に信号を記録する場合
に良く行なわれる。また、最近新しい光記録材料
の開発に伴つて、光デイスクにデイジタル信号や
ビデオ信号の光学的記録再生が行なわれている。
また、簡易な装置で高密度の信号の記録再生を行
なうために、光学的に検出可能な案内トラツクを
有するデイスクを用い、この案内トラツクに沿つ
てあるいは案内トラツク内に信号を記録再生する
ことが行なわれている。Conventional configurations and their problems Recording and reproducing signals at high density on optical recording disks by narrowing the light of a laser or other device to a beam with a diameter of 1 μm or less is often done when recording signals on the master disc of a video disk. . Furthermore, with the recent development of new optical recording materials, optical recording and reproduction of digital signals and video signals is being carried out on optical disks.
In addition, in order to record and reproduce high-density signals with a simple device, it is possible to use a disk with an optically detectable guide track and record and reproduce signals along or within this guide track. It is being done.
第１図に案内トラツク１を有する光記録デイス
ク２の一例を示す。上記のような案内トラツクの
一例として、深さが記録再生に使用する光源の光
の波長の約1/4で、幅がＷ（0.5〜1μm）の溝を用
いることが提案されている。この溝は、デイスク
上の信号記録領域の全面にわたつてスパイラル状
あるいは同心円状に適当なトラツクピツチＰで配
置される。 An example of an optical recording disk 2 having a guide track 1 is shown in FIG. As an example of the above-mentioned guide track, it has been proposed to use a groove with a depth of about 1/4 of the wavelength of light from a light source used for recording and reproduction and a width of W (0.5 to 1 .mu.m). These grooves are arranged spirally or concentrically at an appropriate track pitch P over the entire signal recording area on the disk.
このようなデイスクに記録材料４を蒸着し、レ
ーザ光を微小スポツト光に絞り照射すると記録材
料の反射率が変化し記録ピツト５が形成される。
第２図に光記録デイスクのフオーマツトの一例を
示す。第２図では、図面の簡略化のために一本の
信号記録トラツクのみを示す。図中、Ｎは、信号
記録トラツクを他のトラツクと区別するために固
有のアドレス番号をあらかじめ記録してある番号
信号を示す。n1，n2，…，nnは、一つの信号記録
トラツクを多数のセクターに分けて使用するため
の各セクターに固有なセクターアドレス信号が記
録されているセクター番地信号を示す。l1，l2，
…，lnは、各セクター番地に対応して必要な情報
信号が記録され再生される情報記録領域を示す。
なお、矢印はデイスクの回転方向を示す。 When a recording material 4 is vapor-deposited on such a disk and a laser beam is focused on and irradiated with a minute spot light, the reflectance of the recording material changes and recording pits 5 are formed.
FIG. 2 shows an example of the format of an optical recording disk. In FIG. 2, only one signal recording track is shown to simplify the drawing. In the figure, N indicates a number signal in which a unique address number is recorded in advance to distinguish the signal recording track from other tracks. n 1 , n 2 , . . . , n n represent sector address signals in which sector address signals unique to each sector are recorded for use by dividing one signal recording track into a large number of sectors. l 1 , l 2 ,
..., ln indicate information recording areas in which necessary information signals are recorded and reproduced corresponding to each sector address.
Note that the arrow indicates the direction of rotation of the disk.
光記録デイスクの記録内容を保証するためには
いくつかの方法がある。例えば記録信号の欠損を
起こす情報記録領域のドロツプアウトを記録前に
検査し、ドロツプアウトが存在するセクターには
記録を行なわないプリチエツク記録方式がある。
第３図にプリチエツク記録機能のある光学的情報
記録再生装置の構成を示す。６は半導体レーザ、
７は集光レンズ、８は例えばビームスプリツタ、
９はトラツキングミラー、１０は絞りレンズを示
す。絞りレンズ１０は半導体レーザ６の光を光記
録デイスク２上で直径1μm程度の光に絞り込む。
１１は光検出器でデイスク２からの反射学を検出
して電気信号に変換する。１２はデイスクモータ
を示し、光記録デイスク２を規定の速度で回転さ
せる。１３は半導体レーザ駆動回路で、半導体レ
ーザー６の光出力を記録、再生に応じて切換を行
い、セクター毎の光変調を行なう回路を示し、制
御装置１７より記録信号が入力される。１４は高
周波増幅器でデイスクからの反射光量の変化を再
生信号として出力することができる。この再生信
号を用いてトラツク番地、セクタ番地の検出をト
ラツク番地検出回路１５およびセクタ番地検出回
路１６で行い、特定のセクター情報領域をアクセ
スする。そしてそのセクター情報領域内のドロツ
プアウトを再生信号により検出し、もし規定個数
以上のドロツプアウトがあれば不良セクターとし
記録を行わず、次に続くセクター情報領域へスキ
ツプする。このように記録信号の保証は復調され
た信号がエラー訂正可能か否かの判断に基づいて
ドロツプアウトの規定個数を定め、規定個数以下
のセクター情報領域のみ記録することにより行
う。第４図は、実際に記録信号を欠損を与えるド
ロツプアウトの形態と光検出器出力信号波形を模
式的に示したものである。第４図ａは溝状案内ト
ラツク１で情報記録領域ｌの一部分を拡大した図
である。溝幅は0.5〜1μmである。第４図ｂは第
４図ａの案内トラツク１のトラツク平行方向の断
面図を示す。１８が溝間平坦部、１９が溝底のレ
ベルを示し、表面には記録材料４が蒸着されてい
る。第４図ｃは第４図ａ，ｂに示す如く案内トラ
ツクにトラツキング制御をかけたときの再生信号
の出力波形を示す。第４図ｄは分割された光検出
器１１の差動増幅器の出力信号波形を示す。第４
図ａにはいくつかのドロツプアウトの形態を模式
的に示してある。２１ａはピンホールと呼ばれて
いる欠陥で案内トラツク上に記録材料４が蒸着さ
れていない部分がある。この場合、反射率が低下
するため、再生信号波形は２２に示す様に変化す
る。一方差動増幅器２０出力の差信号は２３の様
に変化する。２４ａ，２４ｂは案内トラツク上に
記録材料の蒸着むら等による付着物がある欠陥を
示している。この場合はドロツプアウトの部分で
反射率が増加するため再生信号出力波形は２５の
様に、差信号出力波形は２６の様に変化する。２
７は案内トラツクの溝形状に欠陥があつたことを
示している。この場合、一般に全反射光量の変化
を示す再生信号には２８のように変化が少なく、
回折像変化が現れるため２９の様に差信号に変化
が大きい。第４図ｃ，ｄに示す様なドロツプアウ
ト検出信号は電圧比較器３０に入力され、波形整
形を行う。電圧比較器の基準電圧は、録再信号の
エンベロープに欠陥を与え、復調エラーを生じる
振幅値を持つドロツプアウトが検出できるレベル
に設定される。第４図ｃ，ｄでは再生信号は３１
ａ，３１ｂの基準電圧レベルで、差信号は３２
ａ，３２ｂの基準電圧のレベルに設定されてい
る。ところで光記録デイスクの反射率は未記録ト
ラツクにおいて15％程度である。この反射率は記
録材料４の蒸着条件の依存度が大きく、反射率で
10〜20％の範囲にバラツキがある。従つてドロツ
プアウト波形の振幅値も２倍程度変化する。３
３，３４，３５，３６に示す点線部の波形は、光
記録デイスクの反射率が低下し、ドロツプアウト
の振幅値が見かけ上小さくなり基準電圧レベル３
１ａ，３１ｂ，３２ａ，３２ｂに達しないためド
ロツプアウト検出が不可能となつた様子を示して
いる。このように反射率が低下したことによりド
ロツプアウトの振幅が減小しても、依然として録
再信号のエンベロープに欠陥を生じ、復調エラー
を起すことには変りはない。以上述べたように従
来の構成では、反射率の違う光記録デイスクを再
生した場合、録再信号に同じ悪影響を与えるドロ
ツプアウトでも、光記録デイスクにより、検出可
能であつたり、不可能であつたりして、ドロツプ
アウト検出の信頼性、安定性を欠く結果となる。
このような状態でデータの記録、再生を行うと、
反射率の低いデイスクにおいては、ドロツプアウ
トの検出能力が低下し、録再に影響を与えるドロ
ツプアウトが存在するセクターにも記録してしま
う。従つて復調エラーが増加し、記録データの信
頼性が著しく低下する。一方反射率の高いデイス
クを再生した場合には、録再信号のエンベロープ
に欠陥を与えないような微小振幅のドロツプアウ
トも検出する。そのため記録不可のセクター領域
と判断してしまい光記録デイスクのセクター利用
効率を低下させ、記録容量が小さくなつてしまう
欠点があつた。 There are several methods to guarantee the recorded contents of an optical recording disk. For example, there is a pre-check recording method in which dropouts in an information recording area that cause recording signal loss are checked before recording, and no recording is performed in sectors where dropouts exist.
FIG. 3 shows the configuration of an optical information recording/reproducing apparatus having a pre-check recording function. 6 is a semiconductor laser;
7 is a condenser lens, 8 is, for example, a beam splitter,
Reference numeral 9 indicates a tracking mirror, and reference numeral 10 indicates an aperture lens. The aperture lens 10 focuses the light from the semiconductor laser 6 onto the optical recording disk 2 to a diameter of approximately 1 μm.
A photodetector 11 detects the reflection from the disk 2 and converts it into an electrical signal. Reference numeral 12 denotes a disk motor, which rotates the optical recording disk 2 at a specified speed. Reference numeral 13 denotes a semiconductor laser drive circuit, which switches the optical output of the semiconductor laser 6 according to recording and reproduction, and performs optical modulation for each sector, to which a recording signal is input from the control device 17. 14 is a high frequency amplifier which can output changes in the amount of reflected light from the disk as a reproduction signal. Using this reproduced signal, the track address and sector address are detected by the track address detection circuit 15 and the sector address detection circuit 16, and a specific sector information area is accessed. Then, dropouts in the sector information area are detected by the reproduction signal, and if there are more than a specified number of dropouts, the sector is determined to be a bad sector and no recording is performed, and the sector is skipped to the next succeeding sector information area. In this way, recording signals are guaranteed by determining a prescribed number of dropouts based on a judgment as to whether the demodulated signal can be error corrected or not, and recording only the sector information area having the prescribed number or less. FIG. 4 schematically shows the form of dropout that actually causes a loss in the recording signal and the waveform of the photodetector output signal. FIG. 4a is an enlarged view of a part of the information recording area 1 of the groove-shaped guide track 1. The groove width is 0.5-1 μm. FIG. 4b shows a sectional view of the guide track 1 of FIG. 4a in a direction parallel to the track. Reference numeral 18 indicates a flat portion between the grooves, and 19 indicates the level of the groove bottom, on the surface of which recording material 4 is deposited. FIG. 4c shows the output waveform of the reproduced signal when tracking control is applied to the guide track as shown in FIGS. 4a and 4b. FIG. 4d shows the output signal waveform of the differential amplifier of the divided photodetector 11. Fourth
Figure a schematically shows several dropout configurations. 21a is a defect called a pinhole, and there is a portion on the guide track where the recording material 4 is not deposited. In this case, since the reflectance decreases, the reproduced signal waveform changes as shown in 22. On the other hand, the difference signal output from the differential amplifier 20 changes as shown in 23. Reference numerals 24a and 24b indicate defects in which deposits are deposited on the guide track due to uneven deposition of the recording material. In this case, since the reflectance increases at the dropout portion, the reproduced signal output waveform changes as shown in 25, and the difference signal output waveform changes as shown in 26. 2
7 indicates that there was a defect in the groove shape of the guide track. In this case, there is generally little change in the reproduced signal indicating the change in the amount of total reflection light, as shown in 28.
Since a change in the diffraction image appears, there is a large change in the difference signal as shown in 29. Dropout detection signals as shown in FIGS. 4c and 4d are input to a voltage comparator 30 and subjected to waveform shaping. The reference voltage of the voltage comparator is set at a level at which a dropout having an amplitude value that causes a defect in the envelope of the recording/reproduction signal and causes a demodulation error can be detected. In Figure 4c and d, the reproduced signal is 31
At the reference voltage level of a, 31b, the difference signal is 32
It is set to the level of the reference voltage of a and 32b. Incidentally, the reflectance of an optical recording disk is about 15% on unrecorded tracks. This reflectance is highly dependent on the deposition conditions of the recording material 4, and the reflectance is
There is variation in the range of 10-20%. Therefore, the amplitude value of the dropout waveform also changes by about twice. 3
In the waveforms shown in the dotted line portions 3, 34, 35, and 36, the reflectance of the optical recording disk decreases, and the amplitude value of the dropout appears to decrease, resulting in a reference voltage level of 3.
1a, 31b, 32a, and 32b, dropout detection is no longer possible. Even if the dropout amplitude decreases due to the decrease in reflectance, defects still occur in the envelope of the recording/reproduction signal and demodulation errors still occur. As described above, in conventional configurations, when optical recording disks with different reflectances are played back, dropouts that have the same negative effect on recording and playback signals may or may not be detectable depending on the optical recording disk. As a result, dropout detection becomes unreliable and unstable.
If you record or play data in such a state,
On discs with low reflectivity, the ability to detect dropouts is reduced, and dropouts that affect recording and playback are recorded even in sectors where they exist. Therefore, demodulation errors increase and the reliability of recorded data decreases significantly. On the other hand, when a disc with a high reflectance is reproduced, a dropout with a minute amplitude that does not cause a defect in the envelope of the recording/reproducing signal is also detected. For this reason, the sector area is determined to be non-recordable, resulting in a decrease in the sector usage efficiency of the optical recording disk, resulting in a reduction in recording capacity.
発明の目的
本発明は上記従来例の問題点を解消するもの
で、反射率の異なる光記録デイスクを再生して
も、録再信号に悪影響を与えるドロツプアウトの
みを確実に検出し、復調後のエラー訂正能力によ
り不良セクターを決定しプリチエツク記録を行う
ことにより復調後のエラーレートを向上させるこ
とを目的とする。Purpose of the Invention The present invention solves the above-mentioned problems of the prior art.Even if optical recording disks with different reflectances are played back, only dropouts that adversely affect the recording/playback signal can be reliably detected, and errors after demodulation can be detected. The purpose of this method is to improve the error rate after demodulation by determining defective sectors based on correction ability and performing pre-check recording.
発明の構成
本発明は、光記録デイスクからの反射光を受光
した光検出器出力信号に含まれるドロツプアウト
の２値化を行う電圧比較器の基準電圧を、光記録
デイスクの反射率の変化と比例した変化を示す前
記光検出器の和信号を用いて発生させるように構
成した光学的記録再生装置であり、反射率の異な
るデイスクを再生しても、録再信号に悪影響を与
えるドロツプアウトのみを確実に検出し、不良セ
クターを判断するため、信頼性の高いプリチエツ
ク記録が可能であり、光記録デイスクの記録内容
の保証には不可欠なものである。Structure of the Invention The present invention sets the reference voltage of a voltage comparator that binarizes a dropout included in a photodetector output signal that receives reflected light from an optical recording disk in proportion to a change in the reflectance of the optical recording disk. This optical recording and reproducing device is configured to generate a signal using the sum signal of the photodetector that indicates a change in reflectance, and even when reproducing discs with different reflectances, it is possible to ensure that only dropouts that adversely affect the recording and reproducing signal are generated. Since this method detects and determines defective sectors, highly reliable pre-check recording is possible, which is essential for guaranteeing the recorded contents of optical recording disks.
実施例の説明
第５図は本発明における一実施例の光学的情報
記録再生装置の構成を示す図である。従来例と同
一構成要素には同一番号を付してある。光記録デ
イスク２からの反射光は光検出器１１で受光し、
高周波増幅器１４に入力されて再生信号として出
力される。再生信号は記録されたデータの復調、
トラツク番地、セクター番地の検出に使われる。
再生信号に現われるドロツプアウト２５は電圧比
較器３０ａに、分割された光検出器の差信号に現
われるドロツプアウト２９は電圧比較器３０ｂに
入力され、各々基準電圧と比較し波形整形されパ
ルス出力される。この基準電圧は従来例３１ａ，
３１ｂに示す様な固定電圧を用いない。再生信号
は、光検出器１１で受けた全反射光量の変化が信
号波形に現われる。しかし高周波増幅器１４を用
いているため、DCから低域の周波数成分は出力
されない。３７は和増幅器であり、受光した全反
射光量のレベルを表わしている。和増幅器３７は
オペアンプ等を用いてDCの周波数成分から増幅
できるが、高周波増幅器１４の様に高域特性は持
たない。従つて和信号は光記録デイスク２の反射
率と比例したレベルを表わしている。和信号出力
はローパスフイルター３８に入力される。ローパ
スフイルターのカツトオフ周波数は、デイスク２
の回転周波数付近に設定される。従つてローパス
フイルターフイルター３８の出力は、デイスク面
そのものの反射率と比例した変化を示し、番地信
号、ドロツプアウト信号波形には応答しない。こ
のローパスフイルター出力を可変抵抗器３９に加
えて、電圧比較器の基準電圧を設定する。反射率
の基準となる光記録デイスクを再生し、復調され
た録再信号がエラー訂正可能か否かの判断に基づ
いて、ドロツプアウト振幅値の許容値に基準電圧
４０を設定する。この様に基準電圧を設定すれ
ば、光記録デイスク２の反射率が変化して、ドロ
ツプアウトの振幅値が見かけ上変化しても、基準
電圧が反射率と比例して変化するため、録再信号
に悪影響を与えるドロツプアウトのみを確実に検
出することができる。第６図は反射率の異なる光
記録デイスクＡとＢにおけるドロツプアウト信号
の波形と、和信号により発生させた基準電圧４０
とのレベル関係を示す図である。第６図ａは再生
信号に現われるドロツプアウト波形で従来例の第
４図ｃに対応している。第６図ｂは差信号に現わ
れるドロツプアウト波形を表しており従来例の第
４図ｄに対応している。光記録デイスクＡは反射
率が高いため録再信号に同程度の悪影響を与える
ドロツプアウトの振幅値も大きい。しかし和信号
により発生させた基準電圧４０ａは、このデイス
クの反射率と比例したレベルになるため、録再信
号に影響を与えないような微小振幅のドロツプア
ウトを検出することはない。一方光記録デイスク
Ｂのように反射率の低い場合は、ドロツプアウト
の振幅値も見かけ上小さくなるが、基準電圧４０
ｃも反射率に比例してレベルが低くなるため、録
再信号に悪影響を与えるドロツプアウトを確実に
検出することができる。なお第５図の電圧比較器
３０ａ，３０ｂは正方向のドロツプアウトを２値
化する構成となつているが、ローパスフイルタ出
力をさらに反転増幅することにより負方向のドロ
ツプアウトを２値化する基準電圧４１ａ〜４１ｄ
を発生させることができる。DESCRIPTION OF EMBODIMENTS FIG. 5 is a diagram showing the configuration of an optical information recording/reproducing apparatus according to an embodiment of the present invention. Components that are the same as those of the conventional example are given the same numbers. The reflected light from the optical recording disk 2 is received by a photodetector 11,
The signal is input to the high frequency amplifier 14 and output as a reproduced signal. The playback signal is demodulated from the recorded data,
Used to detect track addresses and sector addresses.
A dropout 25 appearing in the reproduced signal is inputted to a voltage comparator 30a, and a dropout 29 appearing in the difference signal of the divided photodetectors is inputted to a voltage comparator 30b, where they are compared with a reference voltage, waveform-shaped, and pulsed. This reference voltage is the conventional example 31a,
A fixed voltage as shown in 31b is not used. In the reproduced signal, a change in the amount of total reflection light received by the photodetector 11 appears in the signal waveform. However, since the high frequency amplifier 14 is used, low frequency components are not output from DC. 37 is a sum amplifier, which represents the level of the amount of total reflected light received. The sum amplifier 37 can amplify the DC frequency component using an operational amplifier or the like, but unlike the high frequency amplifier 14, it does not have high frequency characteristics. Therefore, the sum signal represents a level proportional to the reflectance of the optical recording disk 2. The sum signal output is input to a low pass filter 38. The cutoff frequency of the low-pass filter is
The rotation frequency is set around the rotation frequency of Therefore, the output of the low-pass filter 38 shows a change proportional to the reflectance of the disk surface itself, and does not respond to the address signal or dropout signal waveform. This low-pass filter output is applied to the variable resistor 39 to set the reference voltage of the voltage comparator. An optical recording disk serving as a reference for reflectance is reproduced, and a reference voltage 40 is set as an allowable value for the dropout amplitude value based on a judgment as to whether or not the demodulated recording/reproduction signal can be error corrected. If the reference voltage is set in this way, even if the reflectance of the optical recording disk 2 changes and the amplitude value of the dropout appears to change, the reference voltage will change in proportion to the reflectance, so the recording/playback signal will change. It is possible to reliably detect only dropouts that have an adverse effect on Figure 6 shows the waveforms of dropout signals on optical recording disks A and B with different reflectances, and the reference voltage 40 generated by the sum signal.
It is a figure showing the level relationship with. FIG. 6a shows a dropout waveform appearing in the reproduced signal and corresponds to FIG. 4c of the conventional example. FIG. 6b shows a dropout waveform appearing in the difference signal, and corresponds to FIG. 4d of the conventional example. Since the optical recording disk A has a high reflectance, the amplitude of dropout, which has a similar adverse effect on the recording/reproduction signal, is also large. However, since the reference voltage 40a generated by the sum signal has a level proportional to the reflectance of the disk, dropouts with minute amplitudes that do not affect the recording/reproducing signal are not detected. On the other hand, when the reflectance is low like optical recording disk B, the dropout amplitude value also appears to be small, but the reference voltage 40
Since the level of c also decreases in proportion to the reflectance, it is possible to reliably detect dropouts that adversely affect recording/reproduction signals. Note that the voltage comparators 30a and 30b in FIG. 5 are configured to binarize the dropout in the positive direction, but the reference voltage 41a binarizes the dropout in the negative direction by further inverting and amplifying the output of the low-pass filter. ~41d
can be generated.
なお図面中、４２はデイジタル復調回路、４３
はエラー訂正回路、４４はドロツプアウト検査回
路である。 In the drawing, 42 is a digital demodulation circuit, and 43 is a digital demodulation circuit.
4 is an error correction circuit, and 44 is a dropout check circuit.
以上述べたように本発明によれば、反射率の異
なる光記録デイスクを再生しても、録再信号の悪
影響を与えるドロツプアウトのみを確実に検出で
きる。従つてドロツプアウトが検出されたセクタ
ーをスキツプして記録すれば、復調後のエラーレ
ートを向上させることができる。 As described above, according to the present invention, even if optical recording disks having different reflectances are reproduced, only dropouts that adversely affect recording/reproduction signals can be reliably detected. Therefore, if the sector in which dropout has been detected is skipped and recorded, the error rate after demodulation can be improved.
発明の効果
本発明の光学的記録再生装置は、記録再生信号
のエンベロープを減少させ復調エラーを起こさせ
る有害なドロツプアウト検出に際し、光記録デイ
スクからの反射光を受光した光検出器出力信号に
含まれるドロツプアウトの２値化を行う電圧比較
器の基準電圧を、光記録デイスクの反射率と比例
したレベルを示す前記光検出器の和信号を用いて
発生させるように構成したので、反射率の異なる
光デイスクを再生しても、録再信号に悪影響を与
えるドロツプアウトのみを確実に検出することが
できる。従つてドロツプアウトが検出されたセク
ターをスキツプして記録すれば、復調後のエラー
レートを向上させることができる。Effects of the Invention The optical recording and reproducing apparatus of the present invention detects a harmful dropout that reduces the envelope of a recording and reproducing signal and causes a demodulation error, and detects a dropout that is included in the output signal of a photodetector that receives reflected light from an optical recording disk. Since the reference voltage of the voltage comparator that binarizes the dropout is generated using the sum signal from the photodetector that indicates a level proportional to the reflectance of the optical recording disk, it is possible to Even when a disc is played back, it is possible to reliably detect only dropouts that adversely affect recording/playback signals. Therefore, if the sector in which dropout has been detected is skipped and recorded, the error rate after demodulation can be improved.
第１図は案内トラツクを有する光記録デイスク
の構造を示す一部断面斜視図、第２図は光記録デ
イスクのフオーマツトを示す図、第３図は従来の
光学的記録再生装置の構成を示すブロツク構成
図、第４図はドロツプアウト検出方法を説明する
ためのドロツプアウト形態図と信号波形図、第５
図は本発明の一実施例における光学的記録再生装
置の構成を示すブロツク構成図、第６図は同実施
例におけるドロツプアウト検出方法を説明するた
めの信号波形図である。
２……光記録デイスク、１１……光検出器、３
０ａ，３０ｂ……電圧比較器、３７……和増幅
器、３９……可変抵抗器、４４……ドロツプアウ
ト検査回路。
FIG. 1 is a partially sectional perspective view showing the structure of an optical recording disk having a guide track, FIG. 2 is a diagram showing the format of the optical recording disk, and FIG. 3 is a block diagram showing the configuration of a conventional optical recording/reproducing device. 4 is a dropout configuration diagram and a signal waveform diagram for explaining the dropout detection method, and 5th is a block diagram.
The figure is a block diagram showing the configuration of an optical recording/reproducing apparatus in one embodiment of the present invention, and FIG. 6 is a signal waveform diagram for explaining a dropout detection method in the same embodiment. 2... Optical recording disk, 11... Photodetector, 3
0a, 30b... Voltage comparator, 37... Sum amplifier, 39... Variable resistor, 44... Dropout test circuit.
Claims (1)
心円状またはスパイラル状の案内トラツクとトラ
ツク番地領域、情報記録領域とを有する光記録デ
イスクに照射し情報を記録再生する手段と、情報
を記録する前に光記録デイスクからの反射光を少
くとも２個以上の分割面を持つた光検出器で受光
し、光記録デイスク面上のドロツプアウトを前記
光検出器のそれぞれの分割面で受光した検出出力
の差信号および／または再生信号を用いて検査す
る手段と、前記光検出器出力信号に含まれるドロ
ツプアウトの２値化を行う電圧比較器の基準電圧
を前記光検出器のそれぞれの分割面で受光した検
出出力の和信号により発生させる手段とを備えた
光学的記録再生装置。1. A means for recording and reproducing information by focusing a light source such as a laser into a minute spot light and irradiating it onto an optical recording disk having a concentric or spiral guide track, a track address area, and an information recording area, and a means for recording and reproducing information; Then, the reflected light from the optical recording disk is received by a photodetector having at least two or more split surfaces, and the dropout on the optical recording disk surface is detected as the detection output of the light received by each of the split surfaces of the photodetector. A means for testing using a difference signal and/or a reproduction signal, and a reference voltage of a voltage comparator for binarizing the dropout included in the output signal of the photodetector, which is received by each divided surface of the photodetector. An optical recording/reproducing device comprising means for generating a signal using a sum signal of detection outputs.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20297283A JPS6095732A (en) | 1983-10-28 | 1983-10-28 | Optical recording and reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20297283A JPS6095732A (en) | 1983-10-28 | 1983-10-28 | Optical recording and reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6095732A JPS6095732A (en) | 1985-05-29 |
| JPH0310170B2 true JPH0310170B2 (en) | 1991-02-13 |
Family
ID=16466206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20297283A Granted JPS6095732A (en) | 1983-10-28 | 1983-10-28 | Optical recording and reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6095732A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5416319B2 (en) * | 1973-10-25 | 1979-06-21 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5416319U (en) * | 1977-07-07 | 1979-02-02 |
-
1983
- 1983-10-28 JP JP20297283A patent/JPS6095732A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5416319B2 (en) * | 1973-10-25 | 1979-06-21 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6095732A (en) | 1985-05-29 |
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