JPS59127223A - Video signal reproducing device - Google Patents
Video signal reproducing deviceInfo
- Publication number
- JPS59127223A JPS59127223A JP58002641A JP264183A JPS59127223A JP S59127223 A JPS59127223 A JP S59127223A JP 58002641 A JP58002641 A JP 58002641A JP 264183 A JP264183 A JP 264183A JP S59127223 A JPS59127223 A JP S59127223A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- frequency
- band
- pilot
- amplifier
- 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
- 238000001514 detection method Methods 0.000 abstract description 4
- 230000010355 oscillation Effects 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 239000000284 extract Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000012937 correction Methods 0.000 description 2
- 239000011295 pitch Substances 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
- G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
- G11B15/46—Controlling, regulating, or indicating speed
- G11B15/467—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven
- G11B15/4673—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating
- G11B15/4675—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking
- G11B15/4676—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking using signals recorded in tracks disposed in parallel with the scanning direction
- G11B15/4677—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking using signals recorded in tracks disposed in parallel with the scanning direction using auxiliary signals, i.e. pilot signals
- G11B15/4678—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking using signals recorded in tracks disposed in parallel with the scanning direction using auxiliary signals, i.e. pilot signals superimposed on the main signal track
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B21/00—Head arrangements not specific to the method of recording or reproducing
- G11B21/02—Driving or moving of heads
- G11B21/10—Track finding or aligning by moving the head ; Provisions for maintaining alignment of the head relative to the track during transducing operation, i.e. track following
- G11B21/103—Track finding or aligning by moving the head ; Provisions for maintaining alignment of the head relative to the track during transducing operation, i.e. track following on tapes
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/584—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes
- G11B5/588—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes by controlling the position of the rotating heads
- G11B5/592—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes by controlling the position of the rotating heads using bimorph elements supporting the heads
- G11B5/5921—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes by controlling the position of the rotating heads using bimorph elements supporting the heads using auxiliary signals, e.g. pilot signals
- G11B5/5922—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes by controlling the position of the rotating heads using bimorph elements supporting the heads using auxiliary signals, e.g. pilot signals superimposed on the main signal
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
Abstract
Description
【発明の詳細な説明】
く技術分野〉
本発明はビデオ信号再生装置に関し、特に自動トラッキ
ング制御装置を備えたビデ第４ｇ号再生装置に関する。DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a video signal reproducing device, and more particularly to a video signal reproducing device No. 4G equipped with an automatic tracking control device.
以下、本発明をビデオ信号を磁気テープ上に記録する磁
気記録再生装置（以下、ＶＴＲ）を例にして説明する。The present invention will be explained below using a magnetic recording/reproducing apparatus (hereinafter referred to as a VTR) that records video signals on a magnetic tape as an example.
〈従来技術の説明〉
近年、高密度記録の進歩に伴い、トラックピッチを狭く
しだ長時間の記録、再生を可能にしたＶＴＲが開発され
ている。この様に狭トラツクピッチで記録されたテープ
を再生する際重要となるのは再生ヘッドを記録済テープ
上トラックにいかにして良好にトラッキングさせるかと
言うことであり、これまでいくつかの方式が提案、実施
されている。従来の一般的な方法は、垂直同期も号に同
期したコントロール信号（以下、ＣＴＬ信号と称す）を
ビデオトラックとは別に専用コントロールトラックにあ
らかじめ記録し、再生時、前記ＣＴ Ｌ イｉ号を用い
てトラッキングを行うものであった。最近、この方式と
は異り、隣接する４つのビデオトランクに夫々異なる４
種の周波数信号（以゛下、４ｆパイロット信号）をビデ
オ信号の各フィールド信号に重畳して記録し、再生時に
は、再生しようとするビデオトラックの両隣接トラック
からの４ｆパイロット信号の再生レベルの差からトラッ
キング信号を得て、両再生レベルを等しくすることでト
ラッキングを得る方式が注目されて来ている。この方式
には、固定ヘッドを必要としない、トラッキング信号用
の専用トラックを必要としない、得られるトラッキング
信号（以下、ＡＴＦ信号と称す）の周波数特性が良好で
、比較的高い周波数成分のトラッキングまで制御可能で
ある等の利点が多い。しかしながら、前記した４周波記
録方式によるＡＴＦ再生信号は、再生ヘッド間の再生効
率のバラツキ、再生ヘッド間のヘッド幅のバラツキもし
くは偏差、再生ヘッドの周波数特性による４ｆパイロツ
トイ）号の再生レベルのバラツキ、４°ｆパイロット信
号の記録レベルのバラツキ、使用するテープによる４ｆ
パイロット信号の再生レベルのバラツキ等の理由で、Ａ
ＴＦ出力信号にフィールド単位で階段状のレベル変動を
生じ易かった。通常、再生時のトラッキング制御は回転
再生ヘッドの回転位相基準に対してキャプスタン軸の回
転位相を制御する方式を採用しているが、その制御対象
であるキャプスタンモータは、その周波数応答特性が一
般的に放出以下である為、前記ＡＴＦ信号のフィールド
ごとに起−こるレベル変動には追従せず、その平均値で
位相制御される。従って、再生ヘッドが回転ドラムに固
定されている方式のヘリカルスキャンＶＴＲでは再生ヘ
ッドごとにトラッキング調整ができないので互いに反対
側に固定されているヘッドから生ずるＡＴＦ信号のノイ
ズ成分の影響を受け、ミストラッキングの原因となって
いた。さらに、再生４ｆパイロット信号のレベル変動は
それに含まれる両隣接トラックからのクロストーク量の
レベル変動も意味しており、この両クロストークの差を
もってＡＴＦ信号としている関係上、レベル変動はその
ままＡＴＦ信号のトラッキングエラー検出感度に影響し
、ひいてはキャプスタン位相制御ループのループゲイン
が変動することを示しており、トラッキング制御の安定
性をかく原因となっていた。<Description of the Prior Art> In recent years, with the progress of high-density recording, VTRs have been developed that have narrower track pitches and are capable of recording and reproducing over long periods of time. When playing back a tape recorded with such a narrow track pitch, the important thing is how to make the playback head track the recorded tape tracks well, and several methods have been proposed so far. ,It has been implemented. In the conventional general method, a control signal synchronized with the vertical synchronization signal (hereinafter referred to as CTL signal) is recorded in advance on a dedicated control track separate from the video track, and during playback, the CTL signal is used. The system was used for tracking. Recently, unlike this method, four adjacent video trunks each have different
A different frequency signal (hereinafter referred to as 4f pilot signal) is superimposed and recorded on each field signal of a video signal, and during playback, the difference in the playback level of 4f pilot signals from both adjacent tracks of the video track to be played back is recorded. A method that obtains tracking by obtaining a tracking signal from a source and making both reproduction levels equal has been attracting attention. This method does not require a fixed head, does not require a dedicated track for tracking signals, has good frequency characteristics of the resulting tracking signal (hereinafter referred to as ATF signal), and can track relatively high frequency components. It has many advantages such as being controllable. However, the ATF reproduction signal by the above-mentioned 4-frequency recording method has variations in reproduction efficiency between reproduction heads, variations or deviations in head width between reproduction heads, and variations in reproduction level of the 4f pilot toy due to frequency characteristics of the reproduction heads. Variation in recording level of 4°f pilot signal, 4f depending on the tape used
Due to reasons such as variations in the reproduction level of the pilot signal,
Step-like level fluctuations tend to occur in the TF output signal on a field-by-field basis. Normally, tracking control during playback uses a method that controls the rotational phase of the capstan shaft relative to the rotational phase reference of the rotating playback head, but the capstan motor that is the object of this control has a frequency response characteristic. Since it is generally lower than the emission level, it does not follow the level fluctuations that occur from field to field of the ATF signal, and the phase is controlled by the average value thereof. Therefore, in a helical scan VTR in which the playback head is fixed to a rotating drum, tracking adjustment cannot be made for each playback head, so it is affected by the noise component of the ATF signal generated from the heads fixed on opposite sides, resulting in mistracking. It was causing this. Furthermore, the level fluctuation of the reproduced 4f pilot signal also means the level fluctuation of the amount of crosstalk from both adjacent tracks included in it, and since the difference between these two crosstalks is used as the ATF signal, the level fluctuation is directly reflected in the ATF signal. This indicates that the tracking error detection sensitivity of the capstan phase control loop is affected, which in turn causes the loop gain of the capstan phase control loop to fluctuate, which is a cause of poor tracking control stability.
〈発明の目的〉
本発明は上述の如き欠点に鑑み、再生パイロット信号の
レベル差が存在しても、良好なトラッキングを行うこと
ができるトラッキング制御信号を得ることができるビデ
オ信号再生装置の提供を目的としている。<Object of the Invention> In view of the above-mentioned drawbacks, the present invention aims to provide a video signal reproducing device capable of obtaining a tracking control signal capable of performing good tracking even if there is a level difference between reproduced pilot signals. The purpose is
〈実施例の説明〉 本発明の一実施例を図面を参照して詳細に説明する。<Explanation of Examples> An embodiment of the present invention will be described in detail with reference to the drawings.
第１図は本実施例の再生装置の基本ブロック図である。FIG. 1 is a basic block diagram of the reproducing apparatus of this embodiment.
図において、ｌｌａ 、１１ｂはテープトラック上に記
録されたビデオ信号、及びトラックに重畳して記録され
た４ｆパイロット信号を再生する為に回転ドラム（不図
示）の対向する位置に取りつけられた再生ヘッド、１２
ａ 、 １２ｂは再生ヘッドｌｌａ 、 ｌｌｂによっ
て再生された信号を前記回転ドラムから取り出す為のロ
ータリートランス、１３ａ 、 １３ｂは前置増幅器、
１４は前記再生ヘッドｌｌａ 、 ｌｌｂが夫々テープ
上を走査している時に再生を行うべく信号ラインを切換
る切換スイッチ、１５は切換スイーツチ１４がらの再生
信号のうちビデオ信号を復調して出力するビデオ信号処
理回路、１６は再生信号のうち４ｆパイロット信号を抜
き出すバンドパスフィルタ、１７は再生ヘッドｌｌａ
、 ｌｌｂの基本的特性、特に前記４ｆパイロット信号
の帯域における周波数特性を補正する為の周波数イコラ
イザ、１８は４ｆパイロット信号の再生出力レベル′を
一定に保つオートゲインコントロール増幅器（以下ＡＧ
Ｃアンプ）、１９は再生された４ｆパイロット信号と、
該パイロット信号と同じ周波数ローテーション（ｆ＋
ｒ ｆｇｓ ｆ４ｔ ｆ！ｌ＋ ｆｌｔ・・・）で発振
する４周波信号との乗算器である。In the figure, lla and 11b are playback heads attached to opposite positions of a rotating drum (not shown) for playing back the video signal recorded on the tape track and the 4f pilot signal recorded superimposed on the track. , 12
a, 12b are rotary transformers for extracting the signals reproduced by the reproducing heads lla, llb from the rotating drum; 13a, 13b are preamplifiers;
Reference numeral 14 denotes a changeover switch that switches the signal line for playback when the playback heads lla and llb scan the tape, and 15 a video signal that demodulates and outputs the video signal of the playback signal from the switch 14. Signal processing circuit, 16 is a band pass filter that extracts the 4f pilot signal from the reproduced signal, 17 is a reproduction head lla
, a frequency equalizer for correcting the basic characteristics of the 4f pilot signal, especially the frequency characteristics in the band of the 4f pilot signal, and 18 an auto gain control amplifier (hereinafter referred to as AG) that keeps the reproduction output level of the 4f pilot signal constant.
C amplifier), 19 is the regenerated 4f pilot signal,
The same frequency rotation (f+
r fgs f4t f! This is a multiplier with a 4-frequency signal that oscillates at 1+flt...).
４ｆパイロット侶号の周波数ｆｌｔ ｆ２． ｆ、、
ｆ、を夫々ｆ＋ ＜ ｆｔ ＜ ｆｓ ＜ ｆ４とした
とき、ｆ、−ｆ、＝ｆ、−ｆ、＝ Ｆ、 、 ｆ４−
ｆ、＝ ｆ、−ｆ、＝ Ｆ、と設定されるが、２０は周
波数Ｆ、近傍の周波数成分のみを抜き出すバンドパスフ
ィルタ、２２は周波数Ｆ、近傍の周波数成分のみを抜き
出すバンドパスフィルタ、２１．２３は夫々周波数Ｆ、
、 Ｆ、の検波回路、２４は差動アンプ、２５は反転
アンプ、２６はヘッド切換パルスに合わせて差動アンプ
２４の出力を用いるか、反転アンプ２５の出力を用いる
かを切換えるスイッチ、２７はスイッチ２６の出力を増
幅するアンプ、２８は再生ヘッド１１ａ。4f pilot's frequency flt f2. f...
When f, respectively, are f+ < ft < fs < f4, f, -f, = f, -f, = F, , f4-
f, = f, -f, = F, where 20 is a frequency F, a band pass filter that extracts only nearby frequency components, 22 is a frequency F, a band pass filter that extracts only nearby frequency components, 21 .23 is the frequency F, respectively.
, F, a detection circuit 24, a differential amplifier, 25 an inverting amplifier, 26 a switch for switching whether to use the output of the differential amplifier 24 or the output of the inverting amplifier 25 in accordance with the head switching pulse, and 27 a switch. An amplifier 28 amplifies the output of the switch 26, and a reproduction head 11a.
１１ｂが切換わった事を示すヘッド切換パルスの入力端
子、２９は４周波信号の入力端子、３０は再生ビデオ信
号の出力゛端子、３１はＡＴＦ信号の出力により再生ヘ
ッド、若しくはキャプスタンモータ等のテープ走行系を
駆動制御するトラッキング制御回路である。11b is an input terminal for a head switching pulse indicating switching, 29 is an input terminal for a 4-frequency signal, 30 is an output terminal for a playback video signal, and 31 is a terminal for controlling the playback head or capstan motor etc. by outputting an ATF signal. This is a tracking control circuit that drives and controls the tape running system.
以下、第１図の動作を説明する。The operation shown in FIG. 1 will be explained below.
不図示１のビデオテープ上にはビデオ信号の各フィール
ド毎にトラックが形成され、夫々のトラックに周波数ｆ
ｌｔ ｆｔ、ｆｔ１ ｆｓのパイロット信号が順番に、
しかもビデオ信号に重畳して記録されている。再生ヘッ
ドｌｌａ’、 ｌｌｂから再生された信号はロータリー
トランス１２ａ 、 １２ｂ 、再生アンプ１３ａ 、
１３ｂ及び切換スイッチ１４を経て、ビデオ信号処理
回路１５及びバンドパスフィルタ１６に出力される。再
生信号のうちビデオ信号成分はビデオ信号処理回路１５
で再生ビデオ信号に復調され、例えはＴＶ受像器等に出
力される。A track is formed on a video tape (not shown) for each field of the video signal, and each track has a frequency f.
The pilot signals of lt ft and ft1 fs are sequentially
Moreover, it is recorded superimposed on the video signal. The signals reproduced from the reproduction heads lla' and llb are transmitted to rotary transformers 12a, 12b, reproduction amplifiers 13a,
13b and the changeover switch 14, the signal is output to the video signal processing circuit 15 and the bandpass filter 16. The video signal component of the reproduced signal is processed by the video signal processing circuit 15.
The signal is demodulated into a reproduced video signal and output to, for example, a TV receiver.
又、再生信号のうちの４ｆパイロット信号はバンドパス
フィルタ１６でその帯域のみが得られ、後で詳細に説明
するイコライザ１７、及びＡＧＣアンプ１８を介して乗
算器１９の一方の入力端子に入力される。乗算器１９の
もう一方の入力端子には再生４ｆパイロット信号の周波
数ローテーションと同じ周波数ローテーションの発振周
波数信号が入力される。従って、乗算器１９からは、発
振周波数信号と再生パイロット信号クロストーク成分の
周波数との差周波数Ｆ、 、 Ｆ２の信号が得られる。Also, the 4f pilot signal of the reproduced signal is filtered in a bandpass filter 16 to obtain only its band, and is inputted to one input terminal of a multiplier 19 via an equalizer 17 and an AGC amplifier 18, which will be explained in detail later. Ru. The other input terminal of the multiplier 19 receives an oscillation frequency signal having the same frequency rotation as that of the regenerated 4f pilot signal. Therefore, the multiplier 19 obtains signals of difference frequencies F, , F2 between the oscillation frequency signal and the frequency of the reproduced pilot signal crosstalk component.
そして周波数Ｆ１近傍の信号はバンドパスフィルタ２ｏ
で、周波数Ｆ２近傍の・君号はバンドパスフィルタ２２
で取ジ出され、夫々検波回路２１．２３で検波される。And the signal near frequency F1 is filtered by band pass filter 2o.
So, the symbol near frequency F2 is the bandpass filter 22.
and detected by detection circuits 21 and 23, respectively.
そして、検波出力は差動アンプ２４で差動増幅され、差
動アンプ２４の出力と該出力を反転アンプ２５で反転し
た出力が交互にアンプ２７に入力され、ＡＴＦ信号が得
られる。ＡＴＦ信号出力はトラッキング制御回路３１に
入力され、不図示のキャプスタンモータの駆動を制御し
てヘッドトラッキングを制御する。The detected output is differentially amplified by a differential amplifier 24, and the output of the differential amplifier 24 and the output obtained by inverting the output by an inverting amplifier 25 are alternately input to an amplifier 27 to obtain an ATF signal. The ATF signal output is input to the tracking control circuit 31, which controls the drive of a capstan motor (not shown) to control head tracking.
第２図は再生ヘッドが良好にオントラックしている状態
での４ｆパイロット信号の再生レベルを示す周波数スペ
クトラムで、（イ）はバンドパスフィルタ１６の出力、
（ロ）はイコライザ１７の出力、（ハ）はＡＧＣアンプ
１８の出力である。FIG. 2 is a frequency spectrum showing the reproduction level of the 4f pilot signal when the reproduction head is well on-track; (a) is the output of the bandpass filter 16;
(b) is the output of the equalizer 17, and (c) is the output of the AGC amplifier 18.
バンドパスフィルタ１６から得られる再生４ｆパイロッ
ト信号は第２図（イ）に示す様に記録及び再生ヘッドの
周波数特性、再生ヘッド１１ａ。The reproduced 4f pilot signal obtained from the bandpass filter 16 has the frequency characteristics of the recording and reproducing heads, and the reproducing head 11a, as shown in FIG. 2(a).
１１ｂの幅が多少異なること、或は取付位置の偏差、再
生ヘッドの効率の違い、使用するビデオテープの周波数
特性等により、各フィールド毎にレベルのバラツキを持
っている。このレベル差のうち、記録、再生ヘッド及び
ビデオテープの周波数特性、特に再生ヘッドの周波数特
性によるレベル差については、前記周波数特性（第２図
（イ）に破線で示す）に対して逆の周波数特性をもつイ
コライザ１７により第２図（ロ）に示す如く補正してい
る。The level varies from field to field due to slight differences in the width of the tape 11b, deviations in mounting position, differences in efficiency of the reproducing head, frequency characteristics of the video tape used, etc. Of this level difference, the level difference due to the frequency characteristics of the recording head, the playback head, and the video tape, especially the frequency characteristics of the playback head, is the frequency that is opposite to the frequency characteristic (shown by the broken line in Figure 2 (a)). An equalizer 17 having a characteristic is used for correction as shown in FIG. 2(b).
従って、トラッキングがずれだ場合には再生トラックに
隣接する前後のトラックからの４ｆパイロット信号の再
生レベルも前記周波数特性を補償する如くイコライザ１
７にょシ補正されるので適正なトラッキング信号が得ら
れる。Therefore, when the tracking is out of alignment, the equalizer 1 adjusts the playback level of the 4f pilot signals from the tracks adjacent to the playback track to compensate for the frequency characteristics.
Since the correction is performed by 7 degrees, an appropriate tracking signal can be obtained.
更に１再生ヘツドｌｌａ 、 ｌｌｂの幅の違い、或は
位置の偏差、再生ヘッドの効率の違い等によるレベルの
差はＡＧＣアンプ１８で第２図（ハ）に示す如く補正さ
れ、再生レベルはＡＧＣレベルに等しくなる。Furthermore, differences in level due to differences in the width of one reproduction head lla, llb, deviation in position, difference in efficiency of the reproduction head, etc. are corrected by the AGC amplifier 18 as shown in FIG. 2 (c), and the reproduction level is equal to the level.
このように構成することにょシトラックごとにＡＴＦ信
号の直流レベル又はゲインが変化することがなくなり、
常に良好なトラッキングが可能となるものである。By configuring in this way, the DC level or gain of the ATF signal does not change for each rack, and
Good tracking is always possible.
尚、本実施例では、イコライザの出力をＡＧＣアンプに
接続しているが、逆にＡＧＣアンプの出力をイコライザ
に接続して構成することも可能である。又、パイロット
信号の帯域における周波数特性を補償する補償手段とし
ては、イコライザの他に、パイロット信号の各周波数を
別々に取り出し、夫々異なる利得のアンプで増幅する様
構成することも可能である。In this embodiment, the output of the equalizer is connected to the AGC amplifier, but it is also possible to connect the output of the AGC amplifier to the equalizer. In addition to the equalizer, the compensating means for compensating the frequency characteristics in the band of the pilot signal may be configured to separately extract each frequency of the pilot signal and amplify each frequency with an amplifier having a different gain.
〈効果の説明〉
以上の如き構成により、ＡＴＦ信号の直流レベル及びゲ
インがトラック毎に変化することがなくな９、良好なＡ
ＴＦ信号を得ることができる為、良好なトラッキング制
御が可能となる。<Description of Effects> With the above configuration, the DC level and gain of the ATF signal do not change from track to track9, resulting in a good ATF signal.
Since a TF signal can be obtained, good tracking control is possible.
第１図は本実施例の再生装置の制御ブロック図、第２図
は再生ヘッドが良好にオントラックしている状態での４
ｆパイロット信号の再生レベルを示す周波数スペクトラ
ムを示す図である。
図において、ｌｌａ 、 ｌｌｂは再生ヘッド、１５は
ビデオ信号処理回路、１６はバンドパスフィルタ、１７
はイコライザ、１８はＡＧＣアンプ、１９は乗算器、３
１はトラッキング制御回路を夫々示す。
出願人 キャノン株式会社FIG. 1 is a control block diagram of the playback device of this embodiment, and FIG. 2 is a control block diagram of the playback device of this embodiment.
FIG. 3 is a diagram showing a frequency spectrum showing the reproduction level of the f pilot signal. In the figure, lla and llb are playback heads, 15 is a video signal processing circuit, 16 is a band pass filter, and 17
is an equalizer, 18 is an AGC amplifier, 19 is a multiplier, 3
1 indicates a tracking control circuit, respectively. Applicant Canon Co., Ltd.
Claims (1)
ックに相異なる周波数のパイロット信号をビデオ信号に
重畳して記録したビデオテープからビデオ信号を再生す
るビデオ信号再生装置に於いて、前記ビデオ信号及び前
記パイロット信号−を再生する再生ヘッドと、前記再生
ヘッドの前記パイロット信号の帯域に於ける周波数特性
を補償する補償手段と、前記パイロット信号の再生レベ
ルを一定に保つＡＧＣアンプとを有することを特徴とす
る自動トラッキング装置を備えたビデオ信号再生装置。In a video signal reproducing apparatus that reproduces a video signal from a video tape recorded by superimposing pilot signals of different frequencies on adjacent tracks on a video signal in order to obtain a tracking control signal during reproduction, the video signal and the pilot The present invention is characterized by comprising a reproducing head for reproducing a signal, compensating means for compensating the frequency characteristics of the reproducing head in the band of the pilot signal, and an AGC amplifier for keeping the reproduction level of the pilot signal constant. Video signal reproducing device with automatic tracking device.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58002641A JPS59127223A (en) | 1983-01-11 | 1983-01-11 | Video signal reproducing device |
| US06/569,781 US4587580A (en) | 1983-01-11 | 1984-01-10 | Video signal reproducing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58002641A JPS59127223A (en) | 1983-01-11 | 1983-01-11 | Video signal reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59127223A true JPS59127223A (en) | 1984-07-23 |
| JPH0263265B2 JPH0263265B2 (en) | 1990-12-27 |
Family
ID=11534993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58002641A Granted JPS59127223A (en) | 1983-01-11 | 1983-01-11 | Video signal reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59127223A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985005522A1 (en) * | 1984-05-11 | 1985-12-05 | Matsushita Electric Industrial Co., Ltd. | Magnetic recording/reproducing apparatus |
-
1983
- 1983-01-11 JP JP58002641A patent/JPS59127223A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985005522A1 (en) * | 1984-05-11 | 1985-12-05 | Matsushita Electric Industrial Co., Ltd. | Magnetic recording/reproducing apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0263265B2 (en) | 1990-12-27 |
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