JPS6150222A - Optical information recording and reproducing device - Google Patents
Optical information recording and reproducing deviceInfo
- Publication number
- JPS6150222A JPS6150222A JP17086784A JP17086784A JPS6150222A JP S6150222 A JPS6150222 A JP S6150222A JP 17086784 A JP17086784 A JP 17086784A JP 17086784 A JP17086784 A JP 17086784A JP S6150222 A JPS6150222 A JP S6150222A
- Authority
- JP
- Japan
- Prior art keywords
- equalizer
- waveform
- aberration
- optical system
- photodetector
- 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
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
Landscapes
- Optical Recording Or Reproduction (AREA)
Abstract
Description
【発明の詳細な説明】
技術分野
本発明は、光学式記録情報再生装置に関し、特にビデオ
ディスクやディジタルオーディオディスク等のディスク
状記録担体の記録情報を再生する光学式記録情報再生装
置に関するものである。TECHNICAL FIELD The present invention relates to an optical recorded information reproducing device, and more particularly to an optical recorded information reproducing device for reproducing recorded information on a disc-shaped record carrier such as a video disc or a digital audio disc. .
背景技術
従来この種の装置として第１図に示すものがあり九〇第
１図において、半導体レーザ１から発せらｆ’ＬＪｔ照
射ビームはコリメータＶンズ２で平行光にさｎ、ハーフ
プリズム３を経た後対物レンズ４によって集光さル、デ
ィスク５の紀鋒面ＳｃＬ上に微小径のスポット光として
結像させら几る。ディスク５の記録面５α上で回折さｎ
ｌｔ光に再び対物レンズ４′！ｉ−通りハーフプリズム
３で反射さ几、平凸レンズ６及びシリンドリカルレンズ
７を経て光検知器８の受光面に導かルる。光検知器８は
受光し７ｊ光を電気信号に変換する０光検出器８の出力
信号は波形等化器９により波形等化さｎ信号処理さｎる
。波形等化器９は第２図に示す如き周波数特性を有し、
高域の利得を上げることにより瞳の開口率を増大させる
。BACKGROUND ART Conventionally, there is a device of this type as shown in FIG. 1.90 In FIG. After that, the light is focused by the objective lens 4 and focused on the optical surface ScL of the disk 5 as a spot light with a minute diameter. diffracted on the recording surface 5α of the disk 5
Objective lens 4' again for lt light! It is reflected by the i-way half prism 3 and guided to the light receiving surface of the photodetector 8 via the plano-convex lens 6 and the cylindrical lens 7. The photodetector 8 receives light and converts the light into an electrical signal.The output signal of the photodetector 8 is waveform-equalized by a waveform equalizer 9 and subjected to signal processing. The waveform equalizer 9 has frequency characteristics as shown in FIG.
The pupil aperture ratio is increased by increasing the high-frequency gain.
かかる構成の記録情報再生装置でに、光学系の残存収ｚ
ｈ避けらｎなく、この収差によりジッターが生じ、再生
ディジタル信号の符号間に干渉が生じることになる。こ
の光学系の残存収差を少なく抑える之めにに、対物レン
ズ、ハーフプリズム等の光学部品の精度を高く保つ必要
があるので、部品が高価なものとなり、従って装置全体
のコストが高くなるという欠点があった。In a recorded information reproducing apparatus with such a configuration, residual condensation of the optical system
This aberration inevitably causes jitter, which causes interference between symbols of the reproduced digital signal. In order to keep the residual aberrations of this optical system to a minimum, it is necessary to keep the precision of optical parts such as the objective lens and half prism high, so the parts become expensive and the cost of the entire device increases. was there.
発明の概要
本発明に、上記のような従来のものの欠点を除去すべく
なざ几たもので、光学系残存収差許容限界を電気的に緩
和することにより、光学部品の要求精度を低減し、安価
な光学式記録情報再生装置を提供することを目的とする
。SUMMARY OF THE INVENTION The present invention has been elaborated to eliminate the drawbacks of the conventional ones as described above, and by electrically relaxing the tolerance limit for residual aberrations in the optical system, the required precision of optical components can be reduced. The purpose is to provide an inexpensive optical recording information reproducing device.
本発明による光学式記録情報再生装置は、光学系残存収
差に応じｍ周波数特性を有する波形等化器を備え、この
波形等化器によって光検出器の出力信号の波形等化を行
うことを特徴としている。The optical recording information reproducing apparatus according to the present invention is characterized in that it is equipped with a waveform equalizer having m frequency characteristics according to the residual aberration of the optical system, and that the waveform equalizer performs waveform equalization of the output signal of the photodetector. It is said that
以下、本発明の実施例を第３図に基づいて説明する。図
中第１図と同等部分は同一符号により示さ几でいる。Hereinafter, an embodiment of the present invention will be described based on FIG. In the figure, parts equivalent to those in FIG. 1 are designated by the same reference numerals.
第３図において、光検知器８と第１の波形等化器９との
間に第２の波形等化器１ｏが設けらｎており、七ノ１以
外は第１図と同じ構成である。第２の波形等化器１０は
光学系残存収差に応じた周波数特性を有し、光検知器８
の出力信号を無収差光学系で読み出した信号と同等な信
号へ補正するものでおる。第１の波形等化器９は、従来
と同様に、第２図に示す如き周波数特性を有し、第２の
波形等化器９の出力信号の高域を増幅して再生信号の開
口度を増加させるためのもので６る。In FIG. 3, a second waveform equalizer 1o is provided between the photodetector 8 and the first waveform equalizer 9, and the configuration is the same as in FIG. 1 except for No. 1. . The second waveform equalizer 10 has frequency characteristics according to the residual aberration of the optical system, and
The output signal is corrected to a signal equivalent to the signal read out by the aberration-free optical system. The first waveform equalizer 9 has frequency characteristics as shown in FIG. 2, as in the past, and amplifies the high frequency range of the output signal of the second waveform equalizer 9 to improve the aperture of the reproduced signal. It is intended to increase 6.
Ｅ ＦＭ （８−ｔｏ −１４Ｍｏｄｕｌａｔｉｏｎ
）信号を無収差光学系で再生しｍ場合の再生信号の波
形を第４図に示す。こｎに対し、収差のある３種類の光
学系Ａ、Ｂ、Ｃでの再生信号の波形を第５図囚。E FM (8-to-14Modulation
) The waveform of the reproduced signal is shown in FIG. 4 when the signal is reproduced by an aberration-free optical system. In contrast, Figure 5 shows the waveforms of the reproduced signals in three types of optical systems A, B, and C that have aberrations.
ｆＢｌ 、 ｔＯＫ示す。第２の波形等化器１０はこｎ
ら光学系Ａ、Ｂ、Ｃの各収差に応じた周波数特性を有す
るので心り、各周波数特性を第６図囚、 ［Ｂ］ 、
ｔｃ）に、１に各等化出力を第７図ｆＡｌ 、 ｔＢｌ
、 （ＣＩＫそｎぞｎ示す。fBl, tOK is shown. The second waveform equalizer 10 is
Since the optical systems A, B, and C have frequency characteristics corresponding to each aberration, the respective frequency characteristics are shown in Figure 6, [B],
tc) and each equalization output to 1 in Fig. 7 fAl, tBl
, (CIK is shown.
第４図の波形と第７図ｕ〜ｔＣＩの各波形との対比から
明らかなように、光学系に収差がありても、その収差に
応じｍ周波数特性を有する第２の波形等化器１０によっ
て電気的に補正を行うことにより、無収差光学系での再
生信号とほぼ同等な信号が得らｎるのである。As is clear from the comparison between the waveform in FIG. 4 and the waveforms u to tCI in FIG. By electrically correcting the aberrations, a signal almost equivalent to the reproduced signal from an aberration-free optical system can be obtained.
第８図には、第２の波形等化器１０の具体的な構成が示
さｎており、当該波形等化器１０はトランスバーサルフ
ィルター構成であって、フィルターの係数が再生信号の
みにより適応的に決定さｎる。今、光検知器８の出力信
号’ｔｕｔ）とすると、この出力信号ｗ（ｔｔは波形等
化器１０によりサンプリングタイムＴ毎にサンプリング
Ｇ” Ｊ＋Ｎ ｒ”ｋ＋Ｎ−１’・・・・・・”ｋ−ｈ
と時系列データとなる。そして各データ”ｋ＋、 に
重みＣ−Ｎ＋）（）＝０置“・・・２Ｎ）を付与した後
加算することにより出力Ａｆｔｌｔ−得る。収差に応じ
て重みＣ−Ｎ＋、を変化させるＣとにより、光学系の収
差により生じるジッターの補正がなさｎるのである。第
８図に示した波形等化器１０は、ＣＣＤ（チャージカッ
プルドデバイス）等の可変遅延素子により実現さｎる。FIG. 8 shows a specific configuration of the second waveform equalizer 10. The waveform equalizer 10 has a transversal filter configuration, and the coefficients of the filter are adaptive to only the reproduced signal. Determined. Now, assuming that the output signal 'tut) of the photodetector 8 is the output signal w (tt), this output signal w (tt) is sampled by the waveform equalizer 10 at every sampling time T. k-h
becomes time series data. Then, the output Aftlt- is obtained by adding a weight C-N+) ()=0 setting "...2N) to each data "k+" and then adding it. By changing the weight C-N+ according to the aberration, the jitter caused by the aberration of the optical system can be corrected. The waveform equalizer 10 shown in FIG. 8 is realized by a variable delay element such as a CCD (charge coupled device).
なお、上記実施例では、第１及び第２の波形等化器９及
び１０を互いに別手段として設けたが、両者を単一の回
路構成とすることも可能である。In the above embodiment, the first and second waveform equalizers 9 and 10 are provided as separate means, but it is also possible to have a single circuit configuration for both.
発明の詳細
な説明したように、本発明によｎば、光学系の収差に応
じｍ周波数特性を有する波形等化器を設け、０の等化器
によって該収差により生ずるジッターを電気的に補正す
るようにしたので、光学部品の要求精度を低く抑えるこ
とができ、対物レンズ等としてグラスチック製品等の安
価な部品を使えるから、安価な光学式記録情報再生装置
が得らｎる。As described in detail, according to the present invention, a waveform equalizer having m-frequency characteristics is provided according to the aberration of the optical system, and jitter caused by the aberration is electrically corrected by the equalizer of 0. This makes it possible to keep the required accuracy of optical parts low, and to use inexpensive parts such as glass products as the objective lens, etc., resulting in an inexpensive optical recording information reproducing apparatus.
第１図は従来例金示す構成図、第２図は第１四における
波形等化器の周波数特性図、第３図は本発明の一実施例
を示す構成図、第４図は無収差光学系での再生信号の波
形図、第５図へ〜ｔｅｌは収差のある３種類の光学系Ａ
−Ｃでの再生信号の波形図、第６図囚〜［Ｃ）は第３図
における第２の区形等化器の該光学系Ａ−Ｃの各収差に
応じｔ周波８特注図、第７図（５）〜（ＣＩは第６図囚
〜ｔｅｌの周波数特注を有する波形等化器の等化出力を
示す波形図、第８図は第３図における第２の波形等化器
の具体例を示す構成図である。
主要部分の符号の説明Fig. 1 is a block diagram showing a conventional example, Fig. 2 is a frequency characteristic diagram of a waveform equalizer in 14, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 is an aberration-free optical To the waveform diagram of the reproduced signal in the system, see Figure 5 ~ tel indicates three types of optical systems A with aberrations.
The waveform diagram of the reproduced signal at -C, Figure 6-[C] is a t-frequency 8 custom-made diagram according to each aberration of the optical system A-C of the second section equalizer in Figure 3. Figure 7 (5) - (CI is a waveform diagram showing the equalized output of the waveform equalizer with a custom frequency of Figure 6 - tel, Figure 8 is a concrete diagram of the second waveform equalizer in Figure 3) It is a configuration diagram showing an example. Explanation of symbols of main parts.
Claims (1)
体から記録情報を読み出すために前記記録担体の記録面
上に微小スポット光を結像させかつ前記記録面を経た光
を前記光検知器に導く光学系とを備えた光学式記録情報
再生装置であつて、前記光学系の収差に応じた周波数特
性を有する波形等化器を備え、前記波形等化器によつて
前記光検知器の出力信号の波形等化を行うことを特徴と
する光学式記録情報再生装置。a photodetector that converts light into an electrical signal; and a photodetector that focuses a minute spot light on the recording surface of the record carrier in order to read recorded information from the disk-shaped record carrier, and that transmits the light that has passed through the recording surface. The optical recording information reproducing apparatus is equipped with an optical system that guides the photodetector to An optical recording information reproducing device characterized by equalizing the waveform of an output signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17086784A JPS6150222A (en) | 1984-08-16 | 1984-08-16 | Optical information recording and reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17086784A JPS6150222A (en) | 1984-08-16 | 1984-08-16 | Optical information recording and reproducing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6150222A true JPS6150222A (en) | 1986-03-12 |
Family
ID=15912781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17086784A Pending JPS6150222A (en) | 1984-08-16 | 1984-08-16 | Optical information recording and reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6150222A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7701818B2 (en) | 2005-09-20 | 2010-04-20 | Hitachi-Lg Data Storage, Inc. | Optical disk apparatus with controller for changing an amount of lifting and a control method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5930249A (en) * | 1982-08-12 | 1984-02-17 | Canon Inc | Method and device for optical information processing |
-
1984
- 1984-08-16 JP JP17086784A patent/JPS6150222A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5930249A (en) * | 1982-08-12 | 1984-02-17 | Canon Inc | Method and device for optical information processing |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7701818B2 (en) | 2005-09-20 | 2010-04-20 | Hitachi-Lg Data Storage, Inc. | Optical disk apparatus with controller for changing an amount of lifting and a control method thereof |
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