JPS5826875B2 - SECAM color video signal recording and playback system - Google Patents
SECAM color video signal recording and playback systemInfo
- Publication number
- JPS5826875B2 JPS5826875B2 JP52102664A JP10266477A JPS5826875B2 JP S5826875 B2 JPS5826875 B2 JP S5826875B2 JP 52102664 A JP52102664 A JP 52102664A JP 10266477 A JP10266477 A JP 10266477A JP S5826875 B2 JPS5826875 B2 JP S5826875B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- signal
- video signal
- carrier color
- color video
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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- Color Television Systems (AREA)
Description
【発明の詳細な説明】
本発明はＳＥＣＡＭ方式カラー映像信号記録再生方式に
係り、ＳＥＣＡＭ方式カラー映像信号の搬送色信号を少
なくとも周波数逓降回路を通して低域へ変換して記録し
、この周波数逓降された搬送色信号を周波数逓倍回路を
通して復元再生することにより、搬送色信号の記録帯域
を狭くしえ、もってカラー反転現象等を殆ど生ずること
なく良好な画面を得ることのできる記録再生方式を提供
することを目的とする。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a SECAM color video signal recording and reproducing method, in which the carrier color signal of the SECAM color video signal is converted to a low frequency signal through at least a frequency down-conversion circuit and recorded. Provided is a recording and reproducing method that can narrow the recording band of the carrier color signal by restoring and reproducing the carrier color signal through a frequency multiplication circuit, thereby obtaining a good screen with almost no color inversion phenomenon. The purpose is to
従来、ＳＥＣＡＭ方式カラー映像信号を磁気記録、再生
する方式の一例として、このカラー映像信号のうち輝度
信号は周波数変調波とし、搬送色信号はこの周波数変調
波とされた輝度信号の周波数帯域よりも低域へ周波数変
換し、これら両信号を周波数分割多重して磁気テープに
記録し、これを再生する方式があった。Conventionally, as an example of a method for magnetically recording and reproducing a SECAM color video signal, the luminance signal of this color video signal is a frequency modulated wave, and the carrier color signal is a frequency band that is higher than the frequency band of the luminance signal that is the frequency modulated wave. There was a method of converting the frequency to a lower frequency range, frequency-division multiplexing these two signals, recording them on a magnetic tape, and reproducing them.
しかるに、ＳＥＣＡＭ方式カラー映像信号においては、
搬送色信号は実質上ＦＭ波で、周波数偏移は約４．４
ＭＨｚ±５００ｋＨｚであり、側波帯まで考慮すると全
帯域は約４．４±ＩＭＨｚである。However, in the SECAM color video signal,
The carrier color signal is essentially an FM wave, with a frequency deviation of approximately 4.4
The frequency is MHz±500kHz, and the total band is approximately 4.4±IMHz when sidebands are considered.
然るに、上記従来方式では、上記搬送色信号を・＼テロ
ダインによる周波数変換によって低域へそのま＼周波数
変換していたため、その中心周波数が単に低域へ変わっ
ただけで周波数偏移帯域幅等は周波数変換前の搬送色信
号と全く同じであり、従って広い記録帯域を要し、この
ため特に一般家庭用ＶＴＲの如き比較的狭帯域で信号を
記録再生する装置に適用した場合は各所で制限を受けて
カラー反転現象が生じ、再生画像が極めて見づらいとい
う欠点があった。However, in the above conventional method, the carrier color signal was directly frequency-converted to the low frequency range by the terodyne frequency conversion, so even if the center frequency was simply changed to the low frequency range, the frequency shift bandwidth etc. It is exactly the same as the carrier color signal before frequency conversion, and therefore requires a wide recording band. Therefore, there are restrictions in various places, especially when applied to a device that records and reproduces signals in a relatively narrow band, such as a general home VTR. As a result, a color reversal phenomenon occurred, making the reproduced image extremely difficult to see.
本発明は上記の欠点を除去したものであり、以下図面と
共にその一実施例について説明する。The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.
第１図は本発明方式の記録系の一実施例のブロック系統
図を示す。FIG. 1 shows a block diagram of an embodiment of a recording system according to the present invention.
同図中、入力端子１より入来したＳＥＣＡＭ方式カラー
映像信号は二分され、一方は低域フィルタ２により輝度
信号が分離酊波され、他方は帯域フィルタ３により搬送
色信号が分離済波される。In the figure, a SECAM color video signal input from input terminal 1 is divided into two parts, one having a luminance signal separated by a low-pass filter 2, and the other having a carrier color signal separated by a bandpass filter 3. .
上記輝度信号は周波数変調器４に供給され、ここで所定
帯域のＦＭ波とされた後、不要成分を除去する高域フィ
ルタ５を経て混合器６に供給される。The luminance signal is supplied to a frequency modulator 4, where it is converted into an FM wave of a predetermined band, and then supplied to a mixer 6 through a high-pass filter 5 that removes unnecessary components.
他方、上記搬送色信号は、周知のように１水平走査期間
毎に交互にＢ−Ｙ信号又はＲ−Ｙ信号で周波数変調され
たＦＭ波（中心周波数約４．４ ＭＨｚ ）で、オート
マチック・カラーレベル・コントロール回路（ＡＣＣ回
路）７に供給されここで所定の一定レベルとされた後、
リミッタ８により振幅制限されて不要ＡＭ成分が除去さ
れる。On the other hand, as is well known, the carrier color signal is an FM wave (center frequency approximately 4.4 MHz) whose frequency is modulated alternately with the B-Y signal or the R-Y signal every horizontal scanning period, and is an automatic color signal. After being supplied to the level control circuit (ACC circuit) 7 and set at a predetermined constant level,
A limiter 8 limits the amplitude and removes unnecessary AM components.
このリミッタ８より取り出された搬送色信号は、本発明
の要部をなす１／２周波数逓降回路を構成するフリップ
フロップ９に供給され、ここでカウントダウンされて周
波数が７に逓降される。The carrier color signal taken out from the limiter 8 is supplied to a flip-flop 9 constituting a 1/2 frequency down-down circuit which is the essential part of the present invention, and is counted down here to down-regulate the frequency to 7.
このフリップフロップ９より取り出された搬送色信号は
、この百円波数逓降により、中心周波数を約２．２ Ｍ
Ｈｚとされると共に、その周波数偏移をフリップフロッ
プ９の入力搬送色信号のそれのｉに縮小されている。The carrier color signal taken out from this flip-flop 9 has a center frequency of approximately 2.2 M due to this 100-circle wave number down-down.
Hz and its frequency deviation is reduced to i of that of the input carrier color signal of the flip-flop 9.
フリップフロップ９より取り出された上記搬送色信号は
周波数変換器１０に供給され、ここで局部発振器１１よ
りの例えば２．８ ＭＨｚの発振周波数により周波数変
換された後、遮断周波数１．５ ＭＨｚの低域フィルタ
ー２を通して中心周波数約６００ｋＨｚの低域変換搬送
色信号として取り出され、更に前記混合器６に供給され
て前記ＦＭ変調波とされた輝度信号と混合される。The carrier color signal taken out from the flip-flop 9 is supplied to a frequency converter 10, where it is frequency-converted by an oscillation frequency of, for example, 2.8 MHz from a local oscillator 11, and then converted to a low cut-off frequency of 1.5 MHz. The signal is passed through a bandpass filter 2 and taken out as a low-pass conversion carrier color signal with a center frequency of about 600 kHz, and further supplied to the mixer 6 where it is mixed with the luminance signal converted into the FM modulated wave.
混合器６の出力混合信号は磁気−＼ラド１３により磁気
テープ１４上に磁気記録される。The output mixed signal of the mixer 6 is magnetically recorded on a magnetic tape 14 by a magnetic tape 13.
ここで、磁気テープ１４上に記録される上記混合信号の
帯域すなわち記録帯域は、フリップフロップ９による低
域変換搬送色信号の周波数偏移の縮小に伴なって小とさ
れている。Here, the band of the mixed signal recorded on the magnetic tape 14, that is, the recording band, is made small as the frequency shift of the low frequency conversion carrier color signal by the flip-flop 9 is reduced.
次に上記の磁気テープ１４からＳＥＣＡＭ方式カラー映
像信号を再生する場合の動作につき説明する。Next, the operation when reproducing a SECAM system color video signal from the above magnetic tape 14 will be explained.
第２図は本発明方式の再生系の一実施例のブロック系統
図を示す。FIG. 2 shows a block diagram of an embodiment of the reproducing system according to the present invention.
磁気・＼ラド１３により再生された混合信号は前置増幅
器１５を通して二分され、一方は遮断周波数１．５ＭＨ
ｚの高域フィルタ１６に供給されてＦＭ波とされている
輝度信号が分離ｐ波され、他方は遮断周波数１．５ Ｍ
Ｈｚの低域フィルター７に供給されて低域変換搬送色信
号が分離Ｆ波される。The mixed signal regenerated by the magnetic/rad 13 is divided into two through a preamplifier 15, one of which has a cutoff frequency of 1.5 MH.
The luminance signal that is supplied to the high-pass filter 16 of
The signal is supplied to a Hz low-pass filter 7, and the low-pass converted carrier color signal is separated into F-waves.
高域フィルター６よりの再生ＦＭ輝度信号は、ＦＭ復調
器１８に供給され、ここでＦＭ復調されて輝度信号に戻
された後混合器１９に供給される。The reproduced FM luminance signal from the high-pass filter 6 is supplied to an FM demodulator 18, where it is FM demodulated and returned to a luminance signal, which is then supplied to a mixer 19.
また低域フィルタ１７よりの中心周波数約６００ｋＨｚ
の再生低域変換搬送色信号は、周波数変換器２０に供給
されＪここで局部発振器２１よりの発振周波数２．８
Ｍｌｌｌｚにより周波数変換されて中心周波数が約２．
２ＭＨｚとされた後２逓倍回路２２に供給される。Also, the center frequency from the low-pass filter 17 is approximately 600kHz.
The reproduced low-pass converted carrier color signal is supplied to a frequency converter 20 where the oscillation frequency from the local oscillator 21 is 2.8.
Mllz converts the frequency so that the center frequency is approximately 2.
After being adjusted to 2 MHz, it is supplied to the doubler circuit 22.
この２逓倍回路２２は例えば両波整流回路で構成されて
おり、周知のように入力ＦＭ波の中心周波数を２倍にす
ると共（こ、各瞬時瞬時における周波数も２倍にするこ
とによって周波数偏移も２倍にされたＦＭ波を出力する
。This doubler circuit 22 is composed of, for example, a double-wave rectifier circuit, and as is well-known, it doubles the center frequency of the input FM wave (and also doubles the frequency at each instantaneous moment, resulting in frequency deviation). It outputs FM waves with twice the frequency.
従って、上記２逓倍回路２２より不要周波数成分を除去
する帯域フィルタ２３を経て取り出された信号は、中心
周波数並びに周波数偏移の両方共に復元されたＳＥＣＡ
Ｍ方式の再生搬送色信号となる。Therefore, the signal extracted from the doubler circuit 22 through the bandpass filter 23 for removing unnecessary frequency components is the SECA signal with both the center frequency and frequency deviation restored.
This becomes an M system reproduction carrier color signal.
この再生搬送色信号は前記混合器１９に供給され、ここ
でＦＭ復調器１８よりの再生輝度信号と混合されＳＥＣ
ＡＭ方式カラー映像信号として出力端子２４より出力さ
れる。This reproduced carrier color signal is supplied to the mixer 19, where it is mixed with the reproduced luminance signal from the FM demodulator 18 and SEC
The signal is output from the output terminal 24 as an AM color video signal.
このように、本実施例によれば搬送色信号を低域へ変換
して記録するに際し、フリップフロップ９により周波数
偏移を縮小して記録し、再生時は２逓倍回路２２で元に
戻すようにしているため、記録帯域が比較的狭帯域の一
般家庭用ＶＴＲに適用した場合においても、カラー反転
現象を殆ど生ずることなく、良好な再生画像を得ること
ができる。In this way, according to the present embodiment, when converting the carrier color signal to a low frequency band and recording it, the flip-flop 9 reduces the frequency deviation and records it, and when reproducing it, the doubler circuit 22 restores it to the original value. Therefore, even when applied to a general home VTR with a relatively narrow recording band, a good reproduced image can be obtained with almost no color inversion phenomenon.
なお、本発明は上記実施例に限定されるものでなく他の
種々の変形例が考えられるものである。Note that the present invention is not limited to the above-mentioned embodiments, and various other modifications are possible.
例えば第１図において周波数逓降と周波数変換との順序
を逆とし、周波数変換器１０及び局部発振器１１をリミ
ッタ８の入力側に設けるようにしてもよい。For example, the order of frequency downlinking and frequency conversion in FIG. 1 may be reversed, and the frequency converter 10 and local oscillator 11 may be provided on the input side of the limiter 8.
上述の如く、本発明になるＳＥＣＡＭ方式カラー映像信
号記録再生方式は、ＳＥＣＡＭ方式カラー映像信号の搬
送色信号を少なくともフリップフロップにより構成され
る１／２周波数逓降回路に通して記録媒体に記録し、こ
の記録媒体から再生した既記録低域変換搬送色信号を周
波数逓倍回路を通して上記ＳＥＣＡＭ方式カラー映像信
号の搬送色信号に復元するようにしたため、従来にくら
べて記録される低域変換搬送色信号の周波数偏移帯域を
縮小でき、従って記録帯域が比較的狭帯域である一般家
庭用ＶＴＲ等に適用してもカラー反転現象を殆ど生ずる
ことのない良好な再生画像を得ることができ、フリップ
フロップを用いて１／２周波数逓降を行っているので逓
降回路の構成が簡単になる等の特長を有するものである
。As described above, the SECAM color video signal recording and reproducing method according to the present invention records the carrier color signal of the SECAM color video signal on a recording medium by passing it through a 1/2 frequency down-down circuit constituted by at least a flip-flop. Since the recorded low-pass converted carrier color signal reproduced from this recording medium is restored to the carrier color signal of the above-mentioned SECAM system color video signal through a frequency multiplication circuit, the recorded low-pass converted carrier color signal is lower than that of the conventional method. It is possible to reduce the frequency shift band of the flip-flop, and therefore, it is possible to obtain good reproduced images with almost no color reversal phenomenon even when applied to general home VTRs etc. whose recording band is relatively narrow. Since the 1/2 frequency step-down is carried out using the 1/2 frequency step-down circuit, the structure of the step-down circuit can be simplified.
第１図は本発明方式の記録系の一実施例のブロック系統
図、第２図は本発明方式の再生系の一実施例のブロック
系統図である。
１・・・・・・ＳＥＣＡＭ方式カラー映像信号入力端子
、８・・・・・・リミッタ、９・・・・・・フリップフ
ロップ、２２・・・・・・２逓倍回路、２４・・・・・
・再生ＳＥＣＡＭ方式カラー映像信号出力端子。FIG. 1 is a block diagram of an embodiment of a recording system according to the present invention, and FIG. 2 is a block diagram of an embodiment of a reproduction system according to the present invention. 1...SECAM color video signal input terminal, 8...Limiter, 9...Flip-flop, 22...2 multiplier circuit, 24...・
- Playback SECAM color video signal output terminal.
Claims (1)
波数変調されている搬送色信号とを分離し、輝度信号を
波数数変調し搬送色信号を該周波数変調された輝度信号
帯域よりも低い帯域へ変換し、これら両信号を混合して
記録媒体に記録し、これをもとのＳＥＣＡＭ方式カラー
映像信号に再生する方式において、上記搬送色信号を少
なくともフリップフロップにより構成される１／２周波
数逓降回路に通して該搬送色信号の周波数偏移帯域を縮
小して記録媒体に記録し、この記録媒体から再生した既
記録低域変換搬送色信号を周波数逓倍回路を通して上記
ＳＥＣＡＭ方式カラー映像信号の搬送色信号に復元する
ことを特徴とするＳＥＣＡＭ方式カラー映像信号記録再
生方式。i Separating a luminance signal and a frequency-modulated carrier color signal from a SECAM color video signal, modulating the luminance signal with wave number and converting the carrier color signal to a band lower than the frequency-modulated luminance signal band; In the method of mixing these two signals, recording them on a recording medium, and reproducing them into the original SECAM color video signal, the carrier color signal is passed through a 1/2 frequency down-converter circuit composed of at least flip-flops. The frequency shift band of the carrier color signal is reduced and recorded on a recording medium, and the recorded low frequency converted carrier color signal reproduced from this recording medium is passed through a frequency multiplication circuit to become the carrier color signal of the SECAM color video signal. A SECAM color video signal recording and reproducing method characterized by restoration.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52102664A JPS5826875B2 (en) | 1977-08-29 | 1977-08-29 | SECAM color video signal recording and playback system |
| FR7824839A FR2402367A1 (en) | 1977-08-29 | 1978-08-28 | Recording and reproduction of SECAM colour signals - requires separation of luminance and chrominance signals for frequency conversion |
| IT27111/78A IT1098743B (en) | 1977-08-29 | 1978-08-29 | SYSTEM FOR THE RECORDING AND / OR REPRODUCTION OF COLOR VIDEO SIGNALS OF THE SECAM SYSTEM |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52102664A JPS5826875B2 (en) | 1977-08-29 | 1977-08-29 | SECAM color video signal recording and playback system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5437426A JPS5437426A (en) | 1979-03-19 |
| JPS5826875B2 true JPS5826875B2 (en) | 1983-06-06 |
Family
ID=14333492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP52102664A Expired JPS5826875B2 (en) | 1977-08-29 | 1977-08-29 | SECAM color video signal recording and playback system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5826875B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53116733A (en) * | 1977-03-22 | 1978-10-12 | Sony Corp | Secam color video signal recording device |
-
1977
- 1977-08-29 JP JP52102664A patent/JPS5826875B2/en not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53116733A (en) * | 1977-03-22 | 1978-10-12 | Sony Corp | Secam color video signal recording device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5437426A (en) | 1979-03-19 |
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