JPS595410A - Digital data detector - Google Patents
Digital data detectorInfo
- Publication number
- JPS595410A JPS595410A JP11179883A JP11179883A JPS595410A JP S595410 A JPS595410 A JP S595410A JP 11179883 A JP11179883 A JP 11179883A JP 11179883 A JP11179883 A JP 11179883A JP S595410 A JPS595410 A JP S595410A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- digital data
- gate
- data detector
- data
- 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
Links
Classifications
-
- 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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/20—Repeater circuits; Relay circuits
- H04L25/24—Relay circuits using discharge tubes or semiconductor devices
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing For Digital Recording And Reproducing (AREA)
- Digital Magnetic Recording (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
〔発明の関連する技術分野〕
この発明はデジタル−データ検知器に関する。この発明
の応用例としては、この検知器をデジタルビデオテープ
レコーダに用いて記録信号の再生に使用することがあシ
、ここではこの応用例について説明する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to digital data detectors. An example of application of the present invention is to use this detector in a digital video tape recorder to reproduce recorded signals, and this application example will be described here.
磁気テープからデジタルデータを再生するとき、テープ
の欠陥のような異常が再生信号の振幅低下を起し、デー
タ検知過程の誤差を生ずる。この問題の効果を低減する
方法の1つけ、再生さhた信号を積分した後制限して、
そのような異常中振幅の低下した信号からの情報の回復
を助けることである。しかし、直流内容を有する記録コ
ードを用いると、再生された信号の零交点が積分処理で
移動するため、この方法はうまく行かな−。この移動は
データ検知過程で誤差を生ずることがある。When reproducing digital data from magnetic tape, anomalies such as defects in the tape cause a decrease in the amplitude of the reproduced signal, resulting in errors in the data sensing process. One way to reduce the effect of this problem is to limit the reproduced signal after integrating it.
The purpose is to aid in the recovery of information from signals with reduced amplitude during such abnormalities. However, if a recorded code with DC content is used, this method does not work because the zero crossing point of the reproduced signal moves due to the integration process. This movement may cause errors in the data sensing process.
今1つの検知法は制限を全く行わない微分器を用いるも
のである。この方法は零交点は正確であるが、検知誤差
を生ずる異常の問題が残る。直流内容を有するコードは
それを持たない同様のコードより多くの情報を含むため
、望ましい。Another detection method is to use a differentiator that does not impose any restrictions. Although this method is accurate at zero crossing points, there remains the problem of anomalies that cause detection errors. Codes with DC content are desirable because they contain more information than similar codes without it.
従って精度のよいコードを再生するデータ検知器が望ま
れる。Therefore, a data detector that reproduces codes with high accuracy is desired.
この発明によるデジタルデータ検知器は、再生さハたデ
ータを微分する微分手段と、その再生されたデータを積
分する積分手段と、その微分手段と積分手段に結合され
、積分されたデータに従つて上記微分されたデータをゲ
ーティングするゲート手段とを特徴とする。The digital data detector according to the present invention includes a differentiating means for differentiating reproduced data, an integrating means for integrating the reproduced data, and a digital data detector coupled to the differentiating means and the integrating means, according to the integrated data. The present invention is characterized by a gate means for gating the differentiated data.
第2図Aは非零復帰インターリーブ型フォーマットで記
録した仮定のデジタルビット列に対する記録ヘッド(図
示せず)の電流を示す。このフォーマットでは、「1」
がそのビットセルの中央で電流遷移を示すが、「0」は
この遷移を示さない。FIG. 2A shows the current in a recording head (not shown) for a hypothetical digital bit stream recorded in a non-return-to-zero interleaved format. In this format, "1"
exhibits a current transition at the center of its bit cell, while a ``0'' does not exhibit this transition.
従ってrOJの長く続くものは比較的直流内容か高く、
周波数内容が低いため、各ビットの検知が困難になる。Therefore, the long-lasting rOJ has a relatively high DC content;
The low frequency content makes it difficult to detect each bit.
第1図はこの発明による検知器のブロック図を示す。磁
気再生ヘッド10が記録されたテープ(図示せず)K接
触して記録された信号を再生し、再生された信号は増幅
器12で増幅された後、等化器14によシ記録再生応答
特性に対して周波数と位相の等化が行わhる。第2図A
の記録信号に対するこの等化信号を第2図BK示す。こ
の等化信号は第2図CK示す出力波形を持つ積分器16
と第2図りに示す出力波形を持つ微分器18に印加され
る。FIG. 1 shows a block diagram of a detector according to the invention. The magnetic reproducing head 10 comes in contact with a recorded tape (not shown) to reproduce the recorded signal, and the reproduced signal is amplified by the amplifier 12 and then passed to the equalizer 14 to determine the recording/reproducing response characteristics. Frequency and phase equalization is performed for h. Figure 2A
This equalized signal for the recorded signal is shown in FIG. 2BK. This equalized signal is transmitted to the integrator 16 having the output waveform shown in FIG.
is applied to the differentiator 18 having an output waveform shown in the second diagram.
第2図Bの正負のピークが第2図C,Dの信号の零交点
と一致することが判る。微分器18の出力信号は第2図
E[示す出力信号を有する制限器20に印加さhる。こ
の出力信号は第2図A、の原信号と零交点が極めて精密
に一致するが、第2図Bの波形か零軸に近いとき、テー
プ、ヘッドおよび増幅器の雑音のような異常によって生
ずる(シェージングとして現力、る)擬似零交点を他に
多数含んでいる。従ってこの擬似零交点は取除かない限
シ「1」と誤解される。擬似零交点を除去するには、制
限器20からの信号を%ビット遅延器22に印加して、
真の零交点がゲート制御信号(上述)の中央に生ずるよ
うにする。遅延器22の出力信号はゲート24の人力に
印加される。It can be seen that the positive and negative peaks in FIG. 2B coincide with the zero crossing points of the signals in FIGS. 2C and D. The output signal of the differentiator 18 is applied to a limiter 20 having an output signal shown in FIG. This output signal has a zero crossing point that matches the original signal in Figure 2A very precisely, but when the waveform in Figure 2B is close to the zero axis, it is caused by abnormalities such as tape, head, and amplifier noise ( As shading, it contains many other pseudo-zero intersections. Therefore, unless this pseudo zero crossing point is removed, it will be mistaken as "1". To remove the false zero crossing, the signal from limiter 20 is applied to a % bit delayer 22;
The true zero crossing point occurs at the center of the gate control signal (described above). The output signal of the delay device 22 is applied to the input of the gate 24.
ゲート制<=j倍信号発生するため、積分器16の出力
を制限器26に印加し、ここで制限された信号を次に単
発(単安定)マルチバイブレーク28に印加する。この
マルチバイブレータ28ハ制限器26からの信号の零交
点によりトリガされる。この単発マルチバイブレータ2
8の出力信号は第2図Gに示すようにほぼ1ビツト長の
持続時間を有し、ゲート24にゲート制御信号として印
加さhる。ゲート24が「開」 (第21EI Gの信
号が高レベル)のとき、ゲート人力点Fの信J8′はゲ
ート出力点Hに通過するが、ゲート24が「閉」(第2
図Gの信号が低レベル)のときはその出力信号がゲート
内のコンデンサ(図示せず)Kよシ前の値を保つ。この
結果出力波形は@2図Hのようになり、第2図Fのよう
な異常を含まないことか判る。この第2図Hの波形を原
波形AJC比較すると、極性が反転して1ビツト長だけ
ずれている以外全く同一の非零復帰インターリーブ型波
形であることが判る。第2図!−(の非零復帰インター
リーブ型出力信号は必要に応じて第2図1の非零復帰型
信号に変換することができる。In order to generate a gated <= j times signal, the output of the integrator 16 is applied to a limiter 26, and the signal limited here is then applied to a single (monostable) multi-by-break 28. The multivibrator 28 is triggered by the zero crossing of the signal from the limiter 26. This single-shot multivibrator 2
The output signal of 8 has a duration of approximately one bit long, as shown in FIG. 2G, and is applied to gate 24 as a gate control signal. When the gate 24 is "open" (the 21st EI G signal is at a high level), the signal J8' at the gate power point F passes through to the gate output point H, but when the gate 24 is "closed" (the 21st EI G signal is at a high level)
When the signal in Figure G is at a low level, the output signal maintains the value before the capacitor (not shown) K in the gate. As a result, the output waveform becomes as shown in Figure 2H, and it can be seen that it does not include the abnormality shown in Figure 2F. When the waveform of FIG. 2H is compared with the original waveform AJC, it is found that they are exactly the same non-zero return interleaved waveforms except that the polarity is reversed and the length is shifted by one bit. Figure 2! The non-return-to-zero interleaved output signal of -( can be converted to the non-return-to-zero signal of FIG. 1 if necessary.
従って、この発明により微分された信号の零交点の正確
な性質と積分された信号の異常の少ない(またはない)
性質が組合されることが容易に理解される。Therefore, the exact nature of the zero crossing points of the differentiated signal and the less (or no) abnormality of the integrated signal according to the present invention
It is easily understood that the properties are combined.
八
形色である。
16・・・積分手段、18・・・微分手段、24・・・
ゲート手段。It is an octahedral color. 16... Integrating means, 18... Differentiating means, 24...
gate means.
Claims (1)
生されたデータを積分する積分手段と、上記微分手段と
上記積分手段に結合さh、積分されたデータに従って上
記微分さねたデータをゲーティングするゲート手段とを
含むデジタルデータ検知装置。(1) Differentiating means for differentiating the reproduced data, integrating means for integrating the reproduced data, coupled to the differentiating means and the integrating means, and calculating the differentiated data according to the integrated data. and gating means for gating.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US39087182A | 1982-06-22 | 1982-06-22 | |
US390871 | 1982-06-22 |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS595410A true JPS595410A (en) | 1984-01-12 |
JPH0376522B2 JPH0376522B2 (en) | 1991-12-05 |
Family
ID=23544285
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP11179883A Granted JPS595410A (en) | 1982-06-22 | 1983-06-21 | Digital data detector |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPS595410A (en) |
DE (1) | DE3322251C2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63209006A (en) * | 1987-02-25 | 1988-08-30 | Toshiba Corp | Signal processing circuit |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3533467C2 (en) * | 1985-09-19 | 1999-01-21 | Tandberg Data | Method and arrangement for the interference-free detection of data contained in data signals |
DE3717981A1 (en) * | 1987-05-27 | 1988-12-08 | Tandberg Data | Method and circuit arrangement for converting analog signals into binary signals |
DE19829985A1 (en) * | 1998-07-04 | 2000-01-05 | Mannesmann Rexroth Ag | Differentiation method for staircase signals |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2135320A1 (en) * | 1971-07-15 | 1973-01-25 | Licentia Gmbh | CIRCUIT THAT DETECTIVES PARTS AND ELIMINATES INTERFERENCE |
US3810232A (en) * | 1972-10-18 | 1974-05-07 | Singer Co | Magnetic memory read system for digital recordings |
-
1983
- 1983-06-21 JP JP11179883A patent/JPS595410A/en active Granted
- 1983-06-21 DE DE19833322251 patent/DE3322251C2/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63209006A (en) * | 1987-02-25 | 1988-08-30 | Toshiba Corp | Signal processing circuit |
Also Published As
Publication number | Publication date |
---|---|
JPH0376522B2 (en) | 1991-12-05 |
DE3322251C2 (en) | 1994-01-13 |
DE3322251A1 (en) | 1983-12-22 |
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