JPH0325701A - Magnetic tape recording and reproducing device - Google Patents
Magnetic tape recording and reproducing deviceInfo
- Publication number
- JPH0325701A JPH0325701A JP1160464A JP16046489A JPH0325701A JP H0325701 A JPH0325701 A JP H0325701A JP 1160464 A JP1160464 A JP 1160464A JP 16046489 A JP16046489 A JP 16046489A JP H0325701 A JPH0325701 A JP H0325701A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- recording
- magnetic tape
- video
- audio
- 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
- 230000005236 sound signal Effects 0.000 claims abstract description 75
- 238000001514 detection method Methods 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 230000003321 amplification Effects 0.000 abstract description 21
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 21
- 238000001228 spectrum Methods 0.000 description 18
- 238000000034 method Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 101710096655 Probable acetoacetate decarboxylase 1 Proteins 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Landscapes
- Television Signal Processing For Recording (AREA)
- Recording Or Reproducing By Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は映像信号，ＦＭ音声信号及びＰＣＭ音声信号
を記録再生する磁気テープ記録再生装置に関し、特にそ
の各記録信号レベルの制御方法に関するものである．
〔従来の技術〕
第３図は映像信号，ＦＭ音声信号及びＰＣＭ音声信号を
同時に記録再生するタイプの従来の磁気テープ記録再生
装置のブロック図、第４図は従来の磁気記録再生装置の
映像信号，ＦＭ音声信号及びＰＣＭ音声信号のスペクト
ルを示す図であり、例えば特開昭６３−２８８４０２号
「回転ヘッド形多重記録再生装置」 （日立）の第１０
図及び第１１図に対応するものである．ここでは例とし
て、映像信号とＦＭ音声信号はＳ−ＶＨＳ方式磁気テー
プ記録再生装置（以下、単にＳ−ＶＨＳ方式ＶＴＲと呼
ぶ）と同様の方式にて記録再生され、ＰＣＭ信号は例え
ば１９８６年ＩＣＡＳＳＰ予稿「ビデオテーブレコーダ
における音声信号のディジタル化に関する研究」に示さ
れたように約２．６ＭｂｐｓのＰＣＭ信号をオフセット
型４相差動位相変！Ｊｌ（以下、単にＯ−ＱＤＰＳＫと
呼ぶ）されて記録再生されるものとしておく．
第３図〜第９図において、１は映像信号記録処理回路、
２は映像信号記録増幅回路、３は回転ドラム、４は映像
信号用磁気ヘッド（ビデオヘッド）５は磁気テープ、６
は映像信号再生増幅回路、７はスイッチ、８は映像信号
再生処理回路、９はＦＭ音声信号記録処理回路、ｌＯは
加算回路、１ｌはＦＭ音声信号記録処理回路、１２はＦ
Ｍ音声信号用磁気ヘッド（ＦＭＡヘッド）、１３はＦＭ
音声信号再生増幅回路、１４ａはＦＭ音声信号のＬチャ
ンネル（Ｌ−ＣＨ）戒分を分離するための帯域通過フィ
ルタ（ＢＰＦ−Ｌ）、１４ｂはＦＭ音声信号のＲチャン
ネル（Ｒ−ＣＨ）戒分を分離するための帯域通過フィル
タ（Ｂ Ｐ Ｆ−Ｒ）、１５はＦＭ音声信号再生処理回
路、１６はＰＣＭ音声信号記録処理部、１７はアナログ
・ディジタル変換回路（ＡＤＣ）、１８はディジタル音
声信号記録処理回路、１９はオフセット型４相差動位相
変調回路（以下、単に４相位相変調回路と呼ぶ）、２０
はＰＣＭ音声信号記録増幅回路、２１はＰＣＭ音声信号
用磁気ヘッド（ＰＣＭヘッド）、２２はＰＣＭ音声信号
再生増幅回路、２３はＰＣＭ音声信号再生処理部、２４
はオフセット型４相差勤位相変調信号復調回路（以下、
単に４相位相復調回路と呼ぶ）、２５はディジタル音声
信号再生処理回路、２６はディジタル・アナログ変換回
路（ＤＡＣ）、２７は映像信号特殊再生用可動磁気ヘッ
ド（特殊再生用可動ヘッド）、２８は特殊再生映像信号
再生増幅回路、２９は特殊再生用可動ヘッド制御回路（
制御回路）、３０はＦＭ変調された輝度信号（以下、単
にＹ−ＦＭ信号と呼ぶ）のスペクトル、３１は低域変換
された色信号（以下、単にＣ（Ｌ）’信号と呼ぶ）のス
ペクトル、３２はＦＭ変調されたＬ−ＣＨ側の音声信号
（以下、単にＦＭＡ−Ｌ信号と呼ぶ）のスペクトル、３
３はＦＭ変調されたＲ−ＣＨ側の音声信号（以下、単に
ＦＭＡ−Ｒ信号と呼ぶ）のスペクトル、３４は４相位相
変調されたＰＣＭ音声信号（以下、単にＱＤＰＳＫ信号
と呼ぶ）のスペクトル、３５は磁気テープ５のベースフ
ィルム、３６は磁気テープ５の磁性層、３７．３８及び
３９は各々磁性層３６に記録されたＦＭ音声信号、ＰＣ
Ｍ音声信号及び映像信号の記録跡（記録層）である。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic tape recording and reproducing device for recording and reproducing video signals, FM audio signals, and PCM audio signals, and particularly relates to a method of controlling the level of each recorded signal. be. [Prior Art] Fig. 3 is a block diagram of a conventional magnetic tape recording and reproducing device of the type that simultaneously records and reproduces video signals, FM audio signals, and PCM audio signals, and Fig. 4 shows video signals of the conventional magnetic recording and reproducing device. , FM audio signal, and PCM audio signal.
This corresponds to Fig. 1 and Fig. 11. Here, as an example, video signals and FM audio signals are recorded and played back using a method similar to that of an S-VHS magnetic tape recording/reproducing device (hereinafter simply referred to as an S-VHS system VTR), and a PCM signal is, for example, a 1986 ICASSP As shown in the preliminary paper "Study on digitization of audio signals in video table recorders", a PCM signal of approximately 2.6 Mbps is converted into an offset type 4-phase differential phase shift! It is assumed that the data is recorded and reproduced using Jl (hereinafter simply referred to as O-QDPSK). In FIGS. 3 to 9, 1 is a video signal recording processing circuit;
2 is a video signal recording amplification circuit; 3 is a rotating drum; 4 is a video signal magnetic head (video head); 5 is a magnetic tape;
1 is a video signal reproduction amplification circuit, 7 is a switch, 8 is a video signal reproduction processing circuit, 9 is an FM audio signal recording processing circuit, 1O is an addition circuit, 1l is an FM audio signal recording processing circuit, 12 is F
M audio signal magnetic head (FMA head), 13 is FM
Audio signal regeneration amplification circuit, 14a is a band pass filter (BPF-L) for separating the L channel (L-CH) division of the FM audio signal, and 14b is the R channel (R-CH) division of the FM audio signal. 15 is an FM audio signal reproduction processing circuit, 16 is a PCM audio signal recording processing section, 17 is an analog-to-digital conversion circuit (ADC), and 18 is a digital audio signal. a recording processing circuit, 19 an offset type four-phase differential phase modulation circuit (hereinafter simply referred to as a four-phase phase modulation circuit), 20;
21 is a PCM audio signal recording amplification circuit; 21 is a PCM audio signal magnetic head (PCM head); 22 is a PCM audio signal reproduction amplification circuit; 23 is a PCM audio signal reproduction processing section; 24
is an offset type four-phase differential phase modulation signal demodulation circuit (hereinafter referred to as
25 is a digital audio signal reproduction processing circuit, 26 is a digital-to-analog conversion circuit (DAC), 27 is a movable magnetic head for special reproduction of video signals (movable head for special reproduction), 28 is a A special reproduction video signal reproduction amplification circuit, 29 a movable head control circuit for special reproduction (
control circuit), 30 is the spectrum of the FM-modulated luminance signal (hereinafter simply referred to as the Y-FM signal), and 31 is the spectrum of the low-frequency converted color signal (hereinafter simply referred to as the C(L)' signal). , 32 is the spectrum of the FM-modulated L-CH side audio signal (hereinafter simply referred to as the FMA-L signal); 3
3 is a spectrum of an FM-modulated R-CH side audio signal (hereinafter simply referred to as an FMA-R signal); 34 is a spectrum of a four-phase phase modulated PCM audio signal (hereinafter simply referred to as a QDPSK signal); 35 is the base film of the magnetic tape 5, 36 is the magnetic layer of the magnetic tape 5, 37, 38 and 39 are the FM audio signals recorded on the magnetic layer 36, and the PC
This is a recording trace (recording layer) of the M audio signal and video signal.
次に動作について説明する．
第３図において、ベースバンドの映像信号は映像信号記
録処理回路１に入力され、上記ベースバンドの映像信号
の輝度信号或分は同期先端レベルが５．４ＭＨｚに、白
ピークレベルが７．０ＭＨｚになるようにＦＭ変調され
、色信号威分は搬送周波数が６２９Ｈｚになるように低
域変換され、各々第４図（ａ）に３０及び３１で示すス
ペクトルを持つＹ−ＦＭ信号及びＣ （Ｌ）信号に変換
された後、加算されＲＦ映像信号として映像信号記録増
幅回路２．回転ドラム３に内蔵されたロータリートラン
ス（図示せず），ビデオへッド４を経由して磁気テーブ
５に記録される．また、上記ビデオヘッド４で再生され
たＲＦ映像信号は映像信号再生増幅回路６により増輻さ
れ、スイッチ７を経由して映像信号再生処理回路８によ
りベースバンドの映像信号に復元される，ＦＭ系音声信
号はＦＭ信号記録処理回路９に入力され、雑音低減処理
がなされた後Ｌ−Ｃ｝！側は１．３ＭＨｚ，Ｒ−ＣＨ側
は１．７Ｍｌ−１ｚの搬送波にて周波数変調され、第４
図（Ｃ）に３２．３３で示すスペクトルを持つＦＭＡ−
Ｌ信号及びＦＭＡ−Ｒ信号に変換され、加算回路１０に
より加算され、ＦＭＡ信号としてＦＭ音声記録増幅回路
１１，回転ドラム３に内蔵されたロータリートランス（
図示せず），ＦＭＡヘッド１２を経由して磁気テープ５
に記録される．また、上記ＦＭＡヘッド１２で再生され
たＦＭＡ信号はＦＭ音声信号再生増幅回路１３により増
幅された後、ＢＰＦ−Ｌ１４ａ及びＢＰＦ−Ｒ １ ４
ｂによりＦＭＡ−Ｌ信号とＦＭＡ−Ｒ信号が分離され
、ＦＭ音声信号再生処理回路１５により周波数変調信号
の復調と雑音低減処理がなされた後、音声信号に復元さ
れる。一方、ＰＣＭ系音声信号はＰＣＭ音声信号記録処
理部１６において、ＡＤＣ １ ７によりディジタル信
号に変換された後、ディジタル音声信号記録処理回路１
８により誤り訂正符号などを付加されてバルスコード変
調され、約２． ６ Ｍ ｂｐｓのＰＣＭ信号に変換さ
れ、４相位相変調回路１９にて例えば２．５ＭＨｚの搬
送波に対してＯ一ＱＤＰＳＫ変調され第４図（ｂ）の３
４で示すような２．５ＭＨｚを中心に±０．６５ＭＨｚ
の帯域幅のスペクトルを持つＱＤＰＳＫ信号としてＰＣ
Ｍ音声記録増幅回路２０．回転ドラム３に内藏されたロ
ータリートランス（図示せず），ＰＣＭヘッド２１を経
由して磁気テープ５に記録される。また、ＰＣＭヘッド
２工で再生されたＱＤＰＳＫ信号はＰＣＭ音声信号再生
増幅回路２２により増幅された後、ＰＣＭ音声信号再生
処理部２３の４相位相復調回路２４によりＰＣＭ信号に
復元され、デイジタル音声信号再生処理回路２５により
誤り訂正などの処理がなされ、ディジタル音声信号に復
元された後、ＤＡＣ２６により音声信号に復元される。Next, we will explain the operation. In FIG. 3, the baseband video signal is input to the video signal recording processing circuit 1, and the luminance signal or synchronization tip level of the baseband video signal is set to 5.4MHz, and the white peak level is set to 7.0MHz. The color signal signal is FM-modulated so that the carrier frequency is 629 Hz, and the color signal signal is low-pass converted so that the carrier frequency is 629 Hz. After being converted into a signal, it is added and sent as an RF video signal to a video signal recording amplification circuit 2. The data is recorded on a magnetic tape 5 via a rotary transformer (not shown) built into the rotating drum 3 and a video head 4. Further, the RF video signal reproduced by the video head 4 is amplified by a video signal reproduction amplification circuit 6, and restored to a baseband video signal by a video signal reproduction processing circuit 8 via a switch 7. The audio signal is input to the FM signal recording processing circuit 9, and after being subjected to noise reduction processing, L-C}! The frequency is modulated by a carrier wave of 1.3MHz on the side and 1.7Ml-1z on the R-CH side, and the fourth
FMA- with the spectrum shown at 32.33 in Figure (C)
The signal is converted into an L signal and an FMA-R signal, added by an adder circuit 10, and then sent as an FMA signal to an FM audio recording amplification circuit 11 and a rotary transformer built in the rotating drum 3 (
(not shown), the magnetic tape 5 via the FMA head 12
is recorded in Further, the FMA signal reproduced by the FMA head 12 is amplified by the FM audio signal reproduction amplification circuit 13, and then transmitted to the BPF-L14a and BPF-R14.
The FMA-L signal and FMA-R signal are separated by b, and the FM audio signal reproduction processing circuit 15 demodulates the frequency modulated signal and performs noise reduction processing, and then restores it to an audio signal. On the other hand, the PCM audio signal is converted into a digital signal by the ADC 1 7 in the PCM audio signal recording processing section 16, and then converted to a digital signal by the digital audio signal recording processing circuit 1.
8, an error correction code etc. are added and pulse code modulation is performed. The signal is converted into a 6 M bps PCM signal, and then O-QDPSK modulated with respect to a 2.5 MHz carrier wave in the 4-phase phase modulation circuit 19 as shown in FIG. 4(b).
±0.65MHz around 2.5MHz as shown in 4
PC as a QDPSK signal with a spectrum of bandwidth
M audio recording amplification circuit 20. The data is recorded on the magnetic tape 5 via a rotary transformer (not shown) housed in the rotating drum 3 and the PCM head 21. In addition, the QDPSK signal reproduced by the PCM head 2 is amplified by the PCM audio signal reproduction amplifier circuit 22, and then restored to a PCM signal by the 4-phase phase demodulation circuit 24 of the PCM audio signal reproduction processing section 23, which converts the QDPSK signal into a digital audio signal. The reproduction processing circuit 25 performs processing such as error correction and restores the digital audio signal, and then the DAC 26 restores the audio signal.
また、ＶＴＲには特殊再生機能（サーチ再生等）があり
、特殊再生時にはテープ送り速度が異なり、磁気ヘッド
位置が固定されたビデオヘッド４では正確に記録軌跡を
走査できないため、特殊再生用可動ヘンド２７が用いら
れる．第５図（ａ）は例えば３倍速再生時のビデオヘッ
ド４によるヘッド軌跡を示す図であり、テープ送り速度
が異なるため、記録軌跡と再生ヘッド軌跡の角度が異な
り、正確に記録軌跡を走査できず、再生出力エンベロー
プは第５図中）に示すようになる。特殊再生用可動ヘッ
ド２７は磁気ヘッド及び磁気ヘッドの位置を変位させる
ためのアクチェエータから構或され、上記アクチュエー
夕には例えばバイモルフ等の電気一機械変換器が用いら
れる．特殊再生時に上記特殊再生用可動ヘッド２７によ
り再生されたＲＦ映像信号は特殊再生映像信号再生増幅
回路２８によって増幅され、制御回路２９に入力される
．制御回路２９は入力される再生出力エンベローブが最
大値になるように特殊再生用可動ヘッド２７のアクチュ
エー夕に対して制御電圧を加え、磁気ヘッドを変位させ
ることにより第５図（ｃ）， （ｄ）に示すように記録
軌跡を特殊再生用可動ヘッド２７が正確に走査し、最大
出力の再生出力エンベローブが常に得られる。特殊再生
映像信号再生増幅回路２８によって増幅されたＲＦ映像
信号はスイッチ７を経由して映像信号再生処理回路８に
よりベースバンドの映像信号に復元される．
次に上記ＲＦ映像信号，ＦＭＡ信号及びＱＤＰＳＫ信号
の磁気テープ上の記録跡について述べる．ほぼ同一の記
録トラックに複数の信号を重ねて記録する多層記録方式
においては各信号がクロストークにより雑音戒分となり
、相互に干渉し合うので各々磁気ヘッドのアジマス角を
変え、干渉の低減を行っている。なお、ＲＦ映像信号，
ＦＭＡ信号及びＱＤＰＳＫ信号の三種類の信号を順次記
録するため記録層が三層となるので、このような”記録
方弐を三層記録と呼ぶことにする．第６図に三層記録方
式による従来の磁気テープ記録再生装置の各記録信号跡
に対して垂直方向の磁気テーブ５の断面図及び各磁気ヘ
ッドの諸元を示す。磁気テープ５の磁性層３６にＦＭＡ
信号，ＱＤＰＳＫ信号，ＲＦ映像信号の順に記録され、
深層側から順にＦＭ音声信号記録層３７，ＰＣＭ音声信
号記録層３８．映像信号記録層３９が形成される．しか
しながら上記磁性層３６は記録される信号に対応した記
録層を有しているわけではなく、磁気ヘッドのへッドギ
ャップ、記録電流などにより定まる記録深さの違いによ
り結果として記録層が形威されているにすぎない．従っ
て、例えばＰＣＭ信号記録層３８の厚さは単にＱＤＰＳ
Ｋ信号記録電流だけで定まらず、ＲＦ映像信号記録電流
によっても変化することになる．
第７図に示す磁気ヘッド付近のＰ点（ｘ，ｙ）における
磁界Ｈ．とＨ，は例えば「磁気記録技術入門」 （総合
電子出版社：１９８８．６）のｐ５２の（５．２）式に
示されるようにヘッドギャップ内の磁界強度をＨ，とす
れば、
μＯ
と表わされる。従って最大記録深さＤ，は（４冫式をで
表わされる．Ｘ軸方向の磁化が重要であるので、（１）
式について考慮する．記録の深さがＤであることは深さ
Ｄにおける磁界Ｈ．が磁気テープの抗磁力Ｈｃに等しく
なったと考え、またへッドギャップ内磁界Ｈ．が記録電
流に比例すると仮定して、Ｘ−０，）Ｆ＝ｗＤ，Ｈ＊
＝ｌ｛ｃ，Ｈ．−Ｃ− １・（３）とおくと、（１）式
は
と書ける．（４）式から記録電流Ｉまたはへッドギャッ
プｇを大きくするか、磁気テープのＨｃを小さくすれば
記録深さＤが大きくなることがわかる。In addition, VTRs have special playback functions (search playback, etc.), and the tape feed speed is different during special playback, and the video head 4, which has a fixed magnetic head position, cannot accurately scan the recording trajectory, so the movable head for special playback is 27 is used. FIG. 5(a) is a diagram showing the head trajectory of the video head 4 during, for example, triple-speed playback. Since the tape feeding speed is different, the recording trajectory and the playback head trajectory have different angles, making it impossible to accurately scan the recording trajectory. First, the reproduction output envelope becomes as shown in FIG. The special reproduction movable head 27 is composed of a magnetic head and an actuator for displacing the position of the magnetic head, and an electro-mechanical converter such as a bimorph is used as the actuator. During special reproduction, the RF video signal reproduced by the special reproduction movable head 27 is amplified by the special reproduction video signal reproduction amplification circuit 28 and input to the control circuit 29. The control circuit 29 applies a control voltage to the actuator of the special playback movable head 27 so that the input playback output envelope reaches its maximum value, and displaces the magnetic head, thereby producing the results shown in FIGS. 5(c) and 5(d). ), the special reproduction movable head 27 accurately scans the recording locus, and the maximum output reproduction output envelope is always obtained. The RF video signal amplified by the special reproduction video signal reproduction amplification circuit 28 is restored to a baseband video signal by the video signal reproduction processing circuit 8 via the switch 7. Next, we will discuss the recording traces of the above-mentioned RF video signal, FMA signal, and QDPSK signal on the magnetic tape. In the multilayer recording method in which multiple signals are recorded overlappingly on almost the same recording track, each signal becomes noise due to crosstalk and interferes with each other, so the azimuth angle of each magnetic head is changed to reduce interference. ing. Note that the RF video signal,
Since three types of signals, FMA signal and QDPSK signal, are recorded sequentially, there are three recording layers, so this type of recording method is called three-layer recording. Figure 6 shows the three-layer recording method. A cross-sectional view of a magnetic tape 5 in a direction perpendicular to each recording signal trace of a conventional magnetic tape recording/reproducing device and specifications of each magnetic head are shown.
signal, QDPSK signal, and RF video signal are recorded in this order.
FM audio signal recording layer 37, PCM audio signal recording layer 38. A video signal recording layer 39 is formed. However, the magnetic layer 36 does not have a recording layer corresponding to the signal to be recorded, and the shape of the recording layer is determined by the difference in recording depth determined by the head gap of the magnetic head, recording current, etc. There is only one. Therefore, for example, the thickness of the PCM signal recording layer 38 is simply QDPS.
It is not determined only by the K signal recording current, but also varies by the RF video signal recording current. The magnetic field H at point P (x, y) near the magnetic head shown in FIG. and H, for example, as shown in equation (5.2) on page 52 of "Introduction to Magnetic Recording Technology" (Songgo Denshi Publishing: June 1988), if the magnetic field strength in the head gap is H, then μO and expressed. Therefore, the maximum recording depth D is expressed as (4).Since the magnetization in the X-axis direction is important, (1)
Consider the expression. The fact that the recording depth is D means that the magnetic field H. is now equal to the coercive force Hc of the magnetic tape, and the magnetic field H in the head gap is considered to be equal to the coercive force Hc of the magnetic tape. Assuming that is proportional to the recording current, X-0,)F=wD,H*
=l{c, H. -C- By setting 1・(3), equation (1) can be written as . It can be seen from equation (4) that the recording depth D can be increased by increasing the recording current I or the head gap g, or by decreasing the Hc of the magnetic tape.
なお、磁気ヘッドギャップ内の磁界Ｈ，は磁気ヘッドが
飽和しなければ（３）式に従うが、飽和した場合磁気ヘ
ッドの飽和磁束密度をＢ．とすれば磁気へッドギャップ
内の飽和磁界は、
で表わされる。ここで、Ｓ−ＶＨＳ方式のＶＴＲの場合
を想定すれば、およそＨｃ−９０００．，Ｂ．−４００
０Ｇである．また、
ｕｏ −４ Ｘ １ ０−’ （Ｈ／ｍ） ，（Ｇ）＝
１ ０−’ ［Ｗｂ／ｍ” ）＝１ ０−’ （Ｈ −
Ａ／ｍ” ）４ ｒｔ Ｘ １ ０−’ （０＠ ）
− （Ａ／ ｍ）であるので（６）式は、
Ｄ． −１．３ ６ ｇ ・
・・（７）と書ける，Ｓ−ＶＨＳ方式ＶＴＲの場合、ビ
デオへッドギャップｇｖ＝０．４μｍ，ＦＭＡヘソドギ
ャップｇＦ＝１．３μｍ程度であるので、ＰＣＭへッド
ギャップｇｒ＝０．５μｍに設定しておく。この場合、
各々の磁気ヘッドの最大記録深さは各々、Ｄｓｔｖ＞−
０．５ ４ ／Ｊｒｎ， ＤＩ（Ｐ＋−０．６ ８
ｕｍ，Ｄ， （，， −１． ７ ６ ａ ｍ
”｛８）程度になる。なお、磁気記
録は複雑であるので上記記録深さは一応の目安である．
一方記録深さの最大値はλ／４（λ：記録波長）である
のでＲＦ映像信号，ＱＤＰＳＫ信号及びＦＭＡ信号の中
心周波数を６．０ＭＨｚ，２．５ＭＨｚ及び１．５ＭＨ
ｚとし、磁気ヘッドと磁気テープの相対速度を５，８ｍ
／ｓとすれば各々、
λ
４
λ
（Ｆ）−０．９７μｍ
・・・（９）
４
？なる．上記（８）式と（９）式から、Ｄａ（Ｆ）−Ｄ
ａ．■
λ
＝１．０８μｍ〉
（Ｆ）＝０．９７μｍ
４
λ
Ｄ喀（ｒ》−
（Ｖ）
４
＝０．４ ４ ｔｌｍ＜ （Ｐ） ＝０．５ ８
ａｍ４
の関係が戒立する．即ち、ＦＭＡ信号に対しては十分な
記録層の厚さがとれるが、ＲＦ映像信号とＱＤＰＳＫ信
号については少なくとも一方の記録層の厚さが不十分に
ならざるを得ないことになる。Note that the magnetic field H in the magnetic head gap follows equation (3) if the magnetic head is not saturated, but if it is saturated, the saturation magnetic flux density of the magnetic head is B. Then, the saturation magnetic field in the magnetic head gap is expressed as . Here, assuming the case of an S-VHS system VTR, approximately Hc-9000. ,B. -400
It is 0G. Also, uo −4 X 1 0−' (H/m) , (G)=
1 0-'[Wb/m'')=10-' (H-
A/m” )4 rt X 1 0-' (0@)
- (A/m), so equation (6) is:D. -1.3 6 g ・
...(7) In the case of an S-VHS system VTR, the video head gap gv = 0.4 μm and the FMA head gap gF = approximately 1.3 μm, so the PCM head gap gr = 0.5 μm is set. put. in this case,
The maximum recording depth of each magnetic head is Dstv>-
0.5 4 /Jrn, DI(P+-0.6 8
um, D, (,, -1. 7 6 a m
It will be approximately {8). Since magnetic recording is complicated, the above recording depth is only a rough guide.
On the other hand, since the maximum value of the recording depth is λ/4 (λ: recording wavelength), the center frequencies of the RF video signal, QDPSK signal, and FMA signal are set to 6.0 MHz, 2.5 MHz, and 1.5 MHz.
z, and the relative speed of the magnetic head and magnetic tape is 5.8 m.
/s, respectively, λ 4 λ (F) - 0.97 μm...(9) 4 ? Become. From the above equations (8) and (9), Da(F)−D
a. ■ λ = 1.08 μm〉 (F) = 0.97 μm 4 λ D (r》- (V) 4 =0.4 4 tlm< (P) =0.5 8
AM4's relationship is in order. That is, although the recording layer can have a sufficient thickness for the FMA signal, at least one of the recording layers must have an insufficient thickness for the RF video signal and the QDPSK signal.
ＰＣＭへッドギャップを０．６μｍより大きくすれば上
記問題点の解決にはなるが、ＱＤＰＳＫ信号の高域戒分
に対するヘッド感度の低下などが問題となるため実用的
ではない．ゆえに、三層記録方式ＶＴＲにおていはＲＦ
映像信号とＱＤ Ｐ Ｓ Ｋ信号の記録電流のバランス
が重要な課題である。Making the PCM head gap larger than 0.6 μm would solve the above problem, but it is not practical because it would cause problems such as a decrease in head sensitivity to the high frequency range of the QDPSK signal. Therefore, in a three-layer recording VTR, RF
An important issue is the balance between the recording currents of the video signal and the QD PSK signal.
第８図はＦＭＡ信号とＱＤＰＳＫ信号の記録電流を固定
し、ＲＦ映像信号の記録電流を変化させた場合のＰＣＭ
信号記録層３８と映像信号記録層３９の変化を示すもの
であり、記録電流設定中心値Ｉ ａｐ＆に対して（ａ）
は０．９ Ｘ Ｉ ｏｐｔ ，（ｂ）はＩ ｏｓｔｔ（
Ｃ）は１．１ｘｌｏｐｔとした場合を示す。ＦＭ音声信
号記録Ｍ３１とＰＣＭ音声信号記録層３８の記録深さＤ
，とＤＰは変化していないが、映像信号記・・・（１ω
録層３９の記録深さＤｖは記録電流に対応して深くなる
。従って、ＰＣＭ音声信号記録層３８の厚さＤ２は小さ
く、映像信号記録層３９の厚さは大きくなる。Figure 8 shows the PCM when the recording current of the FMA signal and QDPSK signal is fixed and the recording current of the RF video signal is changed.
It shows the changes in the signal recording layer 38 and the video signal recording layer 39, and (a) with respect to the recording current setting central value I ap&.
is 0.9 X I opt , (b) is I ostt (
C) shows the case of 1.1xlopt. Recording depth D of FM audio signal recording M31 and PCM audio signal recording layer 38
, and DP remains unchanged, but video signal recording... (1ω) The recording depth Dv of the recording layer 39 increases in accordance with the recording current. Therefore, the thickness D2 of the PCM audio signal recording layer 38 becomes smaller. , the thickness of the video signal recording layer 39 increases.
第９図と第１０図は第８図に示す記録条件に対応するＰ
ＣＭヘッド１９の再生信号スペクトル（ＥＰモードの例
）とＰＣＭブロックエラーレートの一例を示す図である
．
第９図に示す再生信号スペクトルはＣ （Ｌ）信号３１
，ＦＭＡ−Ｌ信号３２，ＦＭＡ−Ｒ信号３３及びＱＤＰ
ＳＫ信号３４の戒分を有するが、ＲＦ映像信号記録電流
Ｉｖによる再生スペクトルの変化はＱＤＰＳＫ信号３４
が最も大であり、Ｉｖ＝０．９ ＩｏｐＬ ， Ｉｏ
ｐＬ ． １．１ １．．ｔと変化させると約２． ５
ｄ Ｂずつ小さくなる．なお、Ｉｖ＝０で示したスペ
クトルはＱＤＰＳＫ信号３４だけを記録した場合の再生
スペクトルである．第１０図のＥＰで示すＰＣＭブロッ
クエラーレートの変化が第９図で示す再生スペクトルに
対応するものであるが、Ｉｖ ””０．９ １。−ｔ
， Ｉ−ｐｔ ， １． １ １。−ｔ と変化させ
るに従い、ＰＣＭブロックエラーレートはほぼ１桁ずつ
悪化している．また、同様にＱＤＰＳＫ信号の記録電流
を変化させた場合にはＰＣＭ音声信号記録層３８の記録
深さＤＰは記録電流に対応して深くなり、ＦＭ音声信号
記録層３７の厚さが減少しＦＭ音声信号の信号対雑音化
（Ｓ／Ｎ）が劣化する．
次に磁気テープ５の特性の影響について述べる．磁気テ
ープの抗磁力ＨｃはＳ−ＶＨＳ用テープで８５０〜９５
００．程度であるが、（４）式に示すようにＨｃも記録
深さを決定する要因の１つであり、８５００．と９５０
０．の違いは記録電流が約１０％変化することに相当し
、従ってＱＤＰＳＫ信号３４の再生信号レベルが約２ｄ
Ｂ変化することを意味する．
以上述べたように三層記録方式磁気テープ記録再生装置
においては各記録層を形威する記録電流や磁気テープの
抗磁力により上記各記録層の厚さが変化し、従って各記
録層の再生信号のＳ／Ｎが変化し、十分なＳ／Ｎが得ら
れなくなることがあった。Figures 9 and 10 show P corresponding to the recording conditions shown in Figure 8.
3 is a diagram showing an example of a reproduced signal spectrum (an example of EP mode) of the CM head 19 and a PCM block error rate. FIG. The reproduced signal spectrum shown in FIG. 9 is the C (L) signal 31.
, FMA-L signal 32, FMA-R signal 33 and QDP
Although it has the precepts of the SK signal 34, changes in the reproduction spectrum due to the RF video signal recording current Iv are similar to the QDPSK signal 34.
is the largest, Iv=0.9 IopL, Io
pL. 1.1 1. ．． If you change it to t, it will be about 2. 5
It decreases by dB. Note that the spectrum indicated by Iv=0 is the reproduced spectrum when only the QDPSK signal 34 is recorded. The change in the PCM block error rate shown by EP in FIG. 10 corresponds to the reproduction spectrum shown in FIG. 9, and Iv ""0.91. -t
, I-pt, 1. 1 1. -t, the PCM block error rate worsens by approximately one order of magnitude. Similarly, when the recording current of the QDPSK signal is changed, the recording depth DP of the PCM audio signal recording layer 38 becomes deeper corresponding to the recording current, the thickness of the FM audio signal recording layer 37 decreases, and the FM The signal-to-noise ratio (S/N) of the audio signal deteriorates. Next, we will discuss the effects of the characteristics of the magnetic tape 5. The coercive force Hc of magnetic tape is 850 to 95 for S-VHS tape.
00. However, as shown in equation (4), Hc is also one of the factors that determines the recording depth, and 8500. and 950
0. The difference corresponds to a change in the recording current of about 10%, and therefore the reproduction signal level of the QDPSK signal 34 changes by about 2d.
B means to change. As mentioned above, in a three-layer recording type magnetic tape recording/reproducing device, the thickness of each recording layer changes due to the recording current that affects each recording layer and the coercive force of the magnetic tape, and therefore the reproduction signal of each recording layer changes. In some cases, the S/N of the image changes, making it impossible to obtain a sufficient S/N.
従来の三層記録方式磁気テープ記録再生装置は以上のよ
うに構威されており、記録電流の変化や磁気テープの抗
磁力の違いなどにより各記録層の厚さなどが変化し、映
像信号，ＰＣＭ音声信号，ＦＭ音声信号のいずれかの信
号のＳ／Ｎが十分でなくなり、映像または音声信号の品
質が劣化するなどの問題があった．
この発明は上記のような問題点を解消するためになされ
たもので、記録電流の変化や磁気テープの抗磁力の違い
に対しても常にほぼ一定の記録層が実現でき、高画質・
高音質の再生信号が得られる磁気テープ記録再生装置を
得ることを目的としている。The conventional three-layer recording type magnetic tape recording/reproducing device is structured as described above, and the thickness of each recording layer changes due to changes in the recording current and differences in the coercive force of the magnetic tape. There were problems such as the S/N of either the PCM audio signal or the FM audio signal becoming insufficient, and the quality of the video or audio signal deteriorating. This invention was made to solve the above-mentioned problems, and it is possible to realize a recording layer that remains almost constant even with changes in recording current and differences in coercive force of magnetic tape, resulting in high image quality and
The object of the present invention is to obtain a magnetic tape recording and reproducing device that can obtain high-quality reproduction signals.
〔課題を解決するための手段］
この発明に係る磁気テープ記録再生装置は、各信号の記
録時に特殊再生用可動ヘッドを用いて同時再生を行い、
再生信号レベルもしくは雑音レベルにより各記録信号の
記録の深さを直接的または間接的に検出し、最適な各記
録信号レベルを選定する手段と、上記選定手段により得
られた適切な各記録信号レベルに利得を制御する手段と
を備えたものである．
〔作用〕
この発明における磁気テープ記録再生装置は、記録信号
を記録と同時に再生することにより、各記録信号の深さ
を直接的または間接的に検出し、各記録信号レベルを適
切な値に制御する構或としたから、各再生信号について
良好なＳ／Ｎが実現できる．
〔実施例〕
以下、この発明の一実施例を図について説明する．
第ｌ図において、１は映像信号処理回路、２は映像信号
記録増幅回路、３は回転ドラム、４はビデオヘッド、５
は磁気テープ、９はＦＭ音声信号記録処理回路、１０は
加算回路、１１はＦＭ音声信号記録処理回路、１２はＦ
ＭＡヘシド、１６はＰＣＭ音声信号記録処理部、２０は
ＰＣＭ音声信号記録増幅回路、２１はＰＣＭヘッド、２
７は特殊再生用可動ヘッド、２８は特殊再生映像信号再
生増幅回路、２９は制御回路、５０は利得制御部、５１
はＹ−ＦＭ信号を分離するための第１のフィルタ（ＢＰ
ＦＩ）、５２はＦＭＡ−Ｌ信号３２及びＦＭＡ−Ｒ信号
３３を分離するための第２のフィルタ（ＢＰＦ２）、５
３はＱＤＰＳＫ信号３４を分離するための第３のフィル
タ（Ｂ Ｐ Ｆ ３ ）、５４〜５６は第１〜第３の検
出回路、４７は係数制御回路、５８〜６０は第１〜第３
の利得可変回路である．
次に動作について説明する。[Means for Solving the Problems] A magnetic tape recording and reproducing apparatus according to the present invention performs simultaneous reproduction using a special reproduction movable head when recording each signal,
A means for directly or indirectly detecting the recording depth of each recording signal based on the playback signal level or noise level and selecting an optimal recording signal level, and an appropriate recording signal level obtained by the above selection means. and a means for controlling the gain. [Operation] The magnetic tape recording/reproducing device of the present invention detects the depth of each recording signal directly or indirectly by reproducing recording signals at the same time as recording, and controls the level of each recording signal to an appropriate value. Since the structure is configured such that a good S/N ratio can be achieved for each reproduced signal. [Example] An example of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a video signal processing circuit, 2 is a video signal recording amplification circuit, 3 is a rotating drum, 4 is a video head, and 5 is a video signal processing circuit.
9 is a magnetic tape, 9 is an FM audio signal recording processing circuit, 10 is an addition circuit, 11 is an FM audio signal recording processing circuit, and 12 is an F
MA Hesid, 16 is a PCM audio signal recording processing section, 20 is a PCM audio signal recording amplification circuit, 21 is a PCM head, 2
7 is a movable head for special reproduction, 28 is a special reproduction video signal reproduction amplification circuit, 29 is a control circuit, 50 is a gain control section, 51
is the first filter (BP
FI), 52 is a second filter (BPF2) for separating the FMA-L signal 32 and FMA-R signal 33;
3 is a third filter (B P F 3 ) for separating the QDPSK signal 34, 54 to 56 are first to third detection circuits, 47 is a coefficient control circuit, and 58 to 60 are first to third filters.
This is a variable gain circuit. Next, the operation will be explained.
第１図における′１〜５，９〜１２，１６，２０，２１
．２７〜２９の動作は第３図と同様であるので説明を一
部省略する．
較像信号，ＦＭ系音声信号及びＰＣＭ系音声信号は各々
の記録信号経路を経由して磁気テープ上に三層記録され
、同時に特殊再生用可動ヘッド２７が記録信号の再生を
行なう．上記再生信号は特殊再生映像信号再生増幅回路
２８により増幅された後、制御回路２９に入力され、制
御回路２９が最大出力の再生エンベローブが常に得られ
るように特殊再生用可動ヘッド２７の位置を変位させる
ので、三層記録された記録軌跡を正確に走査することに
なる。第２図（ａ）に特殊再生用可動ヘッド２７で再生
された再生信号スペクトルを示す。特殊再生用可動へッ
ド２７は±６″のアジマス角に設定されており、同一ア
ジマス角で記録されているＹ−ＦＭ信号３０，Ｃ（Ｌ）
信号３１については通常の再生信号レベルが得られるが
、Ｆ Ｍ Ａ − Ｌ信号３２，ＦＭＡ−Ｒ信号３３，
ＱＤＰＳＫ信号３４については異なったアジマス角で記
録されているため、クロストークによる雑音或分として
再生される．上記再生信号は制御回路２９以外に利得制
御部５０にも入力され、各記録信号レベルの良否の判定
が行われる。Ｙ−ＦＭ信号３０，ＦＭＡ−Ｌ信号３２，
ＦＭＡ−Ｒ信号３３及びＱＤＰＳＫ信号３４については
再生信号レベルの検出を容易にするため、第ｌのＢＰＦ
５ １．第２のＢＰＦ５２．第３のＢＰＦ５３によって
帯域制限され、第２図（ｂ）． （Ｃ）， （ｄ）で示
すような信号スペクトルとなる．第２図（ｂ）， （Ｃ
）． （ψで示す再生信号は各々検出回路５４〜５６に
より再生信号レベルが検出され、係数制御回路５７に送
られ、記録モード信号（ＳＰ／ＥＰ），ヘッド切替信号
（Ｈ−ＳＷ）により記録モード記録跡に対応して上記再
生信号レベルが設定値に対して大きいか小さいかを判定
し、各信号レベルが各々の設定値を満足するように第１
〜第３の利得可変回路５８〜６０により各記録信号レベ
ルを制御する．
以上により、ＦＭ音声信号，ＰＣＭ音声信号，及び映偽
信号を順に重ねて記録する三層記録方式の磁気テープ記
録再生装置における各記録層の記録状態を常に適切な値
に制御できる。'1-5, 9-12, 16, 20, 21 in Figure 1
．． Since the operations 27 to 29 are the same as those shown in FIG. 3, some explanations will be omitted. The calibration signal, FM audio signal, and PCM audio signal are recorded in three layers on the magnetic tape via respective recording signal paths, and at the same time, the special reproduction movable head 27 reproduces the recorded signals. The playback signal is amplified by the special playback video signal playback amplification circuit 28 and then input to the control circuit 29, and the control circuit 29 displaces the position of the special playback movable head 27 so that the maximum output playback envelope is always obtained. Therefore, the recording locus recorded in three layers can be accurately scanned. FIG. 2(a) shows a reproduction signal spectrum reproduced by the special reproduction movable head 27. The special reproduction movable head 27 is set at an azimuth angle of ±6'', and the Y-FM signal 30, C (L) recorded at the same azimuth angle.
For signal 31, a normal reproduction signal level is obtained, but for FMA-L signal 32, FMA-R signal 33,
Since the QDPSK signal 34 is recorded at different azimuth angles, it is reproduced as some noise due to crosstalk. In addition to the control circuit 29, the reproduction signal is also input to a gain control section 50, and the quality of each recording signal level is determined. Y-FM signal 30, FMA-L signal 32,
Regarding the FMA-R signal 33 and the QDPSK signal 34, in order to facilitate detection of the reproduction signal level, the first BPF
5 1. Second BPF52. Bandwidth is limited by the third BPF 53, as shown in FIG. 2(b). The signal spectrum will be as shown in (C) and (d). Figure 2(b), (C
). (The reproduction signal level of the reproduction signal indicated by ψ is detected by the detection circuits 54 to 56, respectively, and is sent to the coefficient control circuit 57, and the recording mode is recorded by the recording mode signal (SP/EP) and head switching signal (H-SW). It is determined whether the reproduced signal level is larger or smaller than the set value in accordance with the trace, and the first
~The third variable gain circuits 58 to 60 control each recording signal level. As described above, it is possible to always control the recording state of each recording layer to an appropriate value in a three-layer recording type magnetic tape recording and reproducing apparatus that sequentially records an FM audio signal, a PCM audio signal, and a video/false signal in an overlapping manner.
なお、上記実施例では三層の各再生信号レベルを検出し
て三層すべての各記録信号レベルを制御するようにした
が、特定の信号のみについて再生信号レベルを検出し、
特定の信号のみについて記録信号レベルを制御してもよ
い．
また映像信号についてはＹ−ＦＭ信号３０についてのみ
再生信号レベルを検出して映像信号記録レベルを制御す
るようにしたが、Ｃ （Ｌ）信号３ｌについても再生信
号レベルを検出し、Ｙ−ＦＭ信号３０及びＣ （Ｌ）信
号３１について各々記録信号レベルを制御してもよい。Note that in the above embodiment, each reproduction signal level of the three layers is detected to control each recording signal level of all three layers, but the reproduction signal level of only a specific signal is detected,
The recording signal level may be controlled only for specific signals. Regarding the video signal, the playback signal level is detected only for the Y-FM signal 30 to control the video signal recording level, but the playback signal level is also detected for the C (L) signal 3l, and the Y-FM signal The recording signal level of each of the signals 30 and 31 may be controlled.
またＦＭ音声信号についてはＦＭＡ−Ｌ信号３２及びＦ
ＭＡ−Ｒ信号３３について同一のフィルタを用いて再生
信号レベルを検出し、ＦＭ音声信号記録レベルを制御し
たが、ＦＭＡ−Ｌ信号３２及びＦＭＡ−Ｒ信号３３を各
々別のフィルタで再生信号レベルを検出し、各々につい
て記録信号レベルを制御してもよいし、いずれか一方に
ついて再生信号レベルを検出し、記録信号レベルを制御
してもよい．
また、上記実施例では三層記録方式について述べたが、
二層記録，四層記録方式であってもよい。Regarding FM audio signals, FMA-L signal 32 and F
The reproduction signal level of the MA-R signal 33 was detected using the same filter and the FM audio signal recording level was controlled, but the reproduction signal level of the FMA-L signal 32 and FMA-R signal 33 was detected using separate filters. The recording signal level may be detected for each of them and the recording signal level may be controlled, or the reproduction signal level may be detected for either one and the recording signal level may be controlled. In addition, although the above embodiment describes a three-layer recording method,
A two-layer recording method or a four-layer recording method may be used.
また、各層に記録される信号はＦＭ音声信号，ＰＣＭ音
声信号及び映像信号としたが、これは他の信号であって
もよいし、各信号の変調方式は他の方式であってもよい
。Further, although the signals recorded in each layer are an FM audio signal, a PCM audio signal, and a video signal, they may be other signals, and the modulation method of each signal may be another method.
以上のように、この発明によれば各記録信号を記録と同
時に特殊再生用可動ヘッドを用いて再生することにより
記録の深さを検出し、各記録信号レベルを適切な値に制
御する構或としたから、常に良好なＳ／Ｎの各再生信号
が得られる磁気テープ記録再生装置を記録レベル検出用
磁気ヘッドを追加することなしに実現できる効果がある
。As described above, according to the present invention, the depth of recording is detected by reproducing each recording signal using a special reproduction movable head at the same time as recording, and the level of each recording signal is controlled to an appropriate value. Therefore, it is possible to realize a magnetic tape recording/reproducing apparatus which can always obtain reproduction signals with a good S/N ratio without adding a recording level detecting magnetic head.
第１図はこの発明の一実施例による磁気テープ記録再生
装置の横戒図、第２図はこの発明の一実施例の特殊再生
用可動ヘッドによる再生信号スペクトルを示す図、第３
図は従来の磁気テープ記録再生装置の構或図、第４図は
映像信号，ＦＭ音声信号及びＰＣＭ音声信号のスペクト
ルを示す図、第５図は特殊再生用可動ヘッドの動作を説
明するための図、第６図は各磁気ヘッドの諸元及び三層
記録による記録跡（記録７！）の一例を説明するための
図、第７図は磁気ヘッドのモデルを示す図、第８図．第
９図，第１０図はそれぞれＲＦ映像信号記録ｔ流に対す
るＰＣＭ音声信号記録層の厚さ，ＱＤＰＳＫ信号の再生
スペクトル．及びＰＣＭ音声信号のブロックエラーレー
トに与える影響の一例を示す図である。
図において、１は映像信号記録処理回路、２は映像信号
記録増幅回路、３は回転ドラム、４はビデオヘッド、５
は磁気テープ、９はＦＭ音声信号記録処理回路、１０は
加算回路、１１はＦＭ音声信号記録処理回路、ｌ２はＦ
ＭＡヘッド、１６ばＰＣＭ音声信号記録処理部、２０は
ＰＣＭ音声信号記録増幅回路、２１はＰＣＭヘッド、２
７は特殊再生用可動ヘッド、２８は特殊再生映像信号再
生増幅回路、２９は制御回路、５０は利得制御部、５ｌ
〜５３は第１ないし第３のＢＰＦ、５４〜５６は第１な
いし第３の検出回路、５７は係数制御回路、５８〜６０
は第１ないし第３の利得制御回路である。
なお図中同一符号は同一又は相当部分を示す。FIG. 1 is a horizontal diagram of a magnetic tape recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a diagram showing a reproduced signal spectrum by a movable head for special reproduction according to an embodiment of the present invention, and FIG.
Figure 4 shows the configuration of a conventional magnetic tape recording and reproducing device, Figure 4 shows the spectrum of a video signal, FM audio signal, and PCM audio signal, and Figure 5 shows a diagram for explaining the operation of a movable head for special reproduction. Figure 6 is a diagram for explaining the specifications of each magnetic head and an example of the recording trace (record 7!) by three-layer recording, Figure 7 is a diagram showing a model of the magnetic head, and Figure 8. Figures 9 and 10 respectively show the thickness of the PCM audio signal recording layer and the reproduction spectrum of the QDPSK signal for the RF video signal recording stream. FIG. 3 is a diagram illustrating an example of the influence on the block error rate of a PCM audio signal. In the figure, 1 is a video signal recording processing circuit, 2 is a video signal recording amplification circuit, 3 is a rotating drum, 4 is a video head, and 5 is a video signal recording processing circuit.
9 is a magnetic tape, 9 is an FM audio signal recording processing circuit, 10 is an addition circuit, 11 is an FM audio signal recording processing circuit, l2 is F
MA head, 16 PCM audio signal recording processing section, 20 PCM audio signal recording amplification circuit, 21 PCM head, 2
7 is a movable head for special reproduction, 28 is a special reproduction video signal reproduction amplification circuit, 29 is a control circuit, 50 is a gain control section, 5l
53 are first to third BPFs, 54 to 56 are first to third detection circuits, 57 are coefficient control circuits, 58 to 60
are first to third gain control circuits. Note that the same reference numerals in the figures indicate the same or equivalent parts.
Claims (1)
、上記音声信号または他の音声信号を映像フィールドに
対応したディジタルデータに変換し、位相変調した音声
位相変調信号と、輝度信号を周波数変調し、色信号を低
域変換して合成した映像信号とを順に磁気テープ上に重
ね記録し再生する磁気テープ記録再生装置であって、 特殊再生時に上記磁気テープ上に記録された映像信号の
トラックを追従する特殊再生用可動磁気ヘッドを有し、 上記音声周波数変調信号、音声位相変調信号及び映像信
号を記録すると同時に該信号を上記可動再生磁気ヘッド
を用いて再生し、各記録信号レベルを検出する検出手段
と、該検出された記録信号レベルに基づいて上記各記録
信号レベルを制御する記録電流制御手段とを備え、 上記各記録信号レベルの最適制御が可能であることを特
徴とする磁気テープ記録再生装置。(1) An audio frequency modulated signal obtained by frequency modulating an audio signal, an audio phase modulated signal obtained by converting the above audio signal or other audio signal into digital data corresponding to a video field and phase modulating it, and a luminance signal that is frequency modulated. A magnetic tape recording and reproducing device that sequentially records and reproduces a video signal synthesized by low-frequency conversion of a color signal on a magnetic tape, which tracks the video signal recorded on the magnetic tape during special playback. It has a movable magnetic head for special reproduction that tracks the audio frequency modulation signal, the audio phase modulation signal, and the video signal, and at the same time reproduces the signals using the movable reproduction magnetic head and detects the level of each recorded signal. Magnetic tape recording comprising a detection means and a recording current control means for controlling each of the recording signal levels based on the detected recording signal level, and capable of optimally controlling each of the recording signal levels. playback device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1160464A JP2584514B2 (en) | 1989-06-22 | 1989-06-22 | Magnetic tape recording / reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1160464A JP2584514B2 (en) | 1989-06-22 | 1989-06-22 | Magnetic tape recording / reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0325701A true JPH0325701A (en) | 1991-02-04 |
| JP2584514B2 JP2584514B2 (en) | 1997-02-26 |
Family
ID=15715510
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1160464A Expired - Fee Related JP2584514B2 (en) | 1989-06-22 | 1989-06-22 | Magnetic tape recording / reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2584514B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05122653A (en) * | 1991-10-29 | 1993-05-18 | Matsushita Electric Ind Co Ltd | Magnetic recording and reproducing device of color video signal and sound signal |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53130006A (en) * | 1977-04-20 | 1978-11-13 | Sony Corp | Frame feed recorder/reproducer |
| JPS61117703A (en) * | 1984-11-12 | 1986-06-05 | Sony Corp | Setting method of recording current |
| JPS63102002A (en) * | 1986-10-17 | 1988-05-06 | Victor Co Of Japan Ltd | Multiplex magnetic recording and reproducing device |
-
1989
- 1989-06-22 JP JP1160464A patent/JP2584514B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53130006A (en) * | 1977-04-20 | 1978-11-13 | Sony Corp | Frame feed recorder/reproducer |
| JPS61117703A (en) * | 1984-11-12 | 1986-06-05 | Sony Corp | Setting method of recording current |
| JPS63102002A (en) * | 1986-10-17 | 1988-05-06 | Victor Co Of Japan Ltd | Multiplex magnetic recording and reproducing device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05122653A (en) * | 1991-10-29 | 1993-05-18 | Matsushita Electric Ind Co Ltd | Magnetic recording and reproducing device of color video signal and sound signal |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2584514B2 (en) | 1997-02-26 |
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