JPH04313980A - Magnetic recording and reproducing device - Google Patents
Magnetic recording and reproducing deviceInfo
- Publication number
- JPH04313980A JPH04313980A JP3060174A JP6017491A JPH04313980A JP H04313980 A JPH04313980 A JP H04313980A JP 3060174 A JP3060174 A JP 3060174A JP 6017491 A JP6017491 A JP 6017491A JP H04313980 A JPH04313980 A JP H04313980A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- noise
- circuit
- luminance signal
- separated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims abstract description 10
- 239000000203 mixture Substances 0.000 claims abstract description 3
- 238000000926 separation method Methods 0.000 claims description 12
- 238000006243 chemical reaction Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 12
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 230000005684 electric field Effects 0.000 description 1
Landscapes
- Television Signal Processing For Recording (AREA)
- Processing Of Color Television Signals (AREA)
- Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
- Picture Signal Circuits (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、磁気記録再生装置（以
下、「ＶＴＲ」という）において、ノイズの多い入力映
像信号を記録する際の画質改善に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the image quality when recording a noisy input video signal in a magnetic recording/reproducing apparatus (hereinafter referred to as "VTR").
【０００２】0002
【従来の技術】図６は、ＶＴＲの記録系の基本構成を示
すブロック回路図である。図において、入力ビデオ信号
は、ＹＣ分離回路１で輝度信号Ｙと色信号Ｃに分離され
、輝度信号Ｙは、エンファシス回路２で高域強調され、
ＦＭ変調器３でＦＭ変調される。他方、色信号Ｃは、ク
ロマ低域変換器６で低域変換され、混合回路４でＦＭ変
調輝度信号と混合され、記録増幅器５を通して、記録ヘ
ッド７によって磁気テープ８に磁気記録される。2. Description of the Related Art FIG. 6 is a block circuit diagram showing the basic configuration of a recording system of a VTR. In the figure, an input video signal is separated into a luminance signal Y and a color signal C by a YC separation circuit 1, and the luminance signal Y is high-frequency emphasized by an emphasis circuit 2.
FM modulation is performed by an FM modulator 3. On the other hand, the color signal C is low frequency converted by a chroma low frequency converter 6, mixed with an FM modulated luminance signal by a mixing circuit 4, and magnetically recorded on a magnetic tape 8 by a recording head 7 through a recording amplifier 5.
【０００３】従来のＶＴＲでは、入力ビデオ信号が、例
えば弱電界地域でのテレビチュ─ナからの受信信号のよ
うにノイズが多い場合、そのまま記録すると、ざらざら
としたノイズも記録されるため、非常に見づらい再生画
面となる。従来、このような時は、再生時に、ＶＴＲや
ＴＶ受像機の画質をソフト側に調整して見やすくなるよ
うにしていた。しかし、思うように調整できないＶＴＲ
やＴＶ受像機も多く、また、再生された画質の状態に応
じてその都度、調整し直さなければならないという不便
もあった。With conventional VTRs, if the input video signal has a lot of noise, such as a signal received from a television tuner in a weak electric field area, if it is recorded as is, rough noise will also be recorded, making it extremely difficult to record. The playback screen becomes difficult to read. Conventionally, in such cases, during playback, the image quality of the VTR or TV receiver was adjusted to the software side to make it easier to see. However, the VTR cannot be adjusted as desired.
and TV receivers, and there was also the inconvenience of having to make readjustments each time depending on the state of the reproduced image quality.
【０００４】0004
【発明が解決しようとする課題】本発明は、上記の様な
課題を解決するためになされたもので、ノイズが多い入
力ビデオ信号であっても、ノイズが抑制された見やすい
画面を再生できるＶＴＲを得ることを目的とする。SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a VTR that can reproduce an easy-to-see screen with suppressed noise even when input video signals have a lot of noise. The purpose is to obtain.
【０００５】[0005]
【課題を解決するための手段】ＹＣ分離回路で分離され
た輝度信号のノイズ成分を除去するノイズキャンセラ回
路と、上記分離された輝度信号の水平同期期間のノイズ
の量を検出し、このノイズ検出量が基準量より多いとき
は上記ノイズキャンセラ回路でノイズが除去された輝度
信号を磁気テープに記録し、ノイズ検出量が基準量より
少ないときは、ＹＣ分離回路で分離された輝度信号を記
録するようにした点を特徴とする。[Means for Solving the Problems] A noise canceler circuit removes noise components of a luminance signal separated by a YC separation circuit, detects the amount of noise in the horizontal synchronization period of the separated luminance signal, and detects the amount of noise detected in the horizontal synchronization period of the separated luminance signal. When the amount of noise detected is greater than the reference amount, the luminance signal from which noise has been removed by the noise canceller circuit is recorded on the magnetic tape, and when the detected amount of noise is less than the reference amount, the luminance signal separated by the YC separation circuit is recorded. It is characterized by the following points.
【０００６】[0006]
【作用】輝度信号のノイズ量の検出を、水平同期期間で
行うようにしたので、輝度信号の画像信号の変化に影響
されることなく、ノイズの量を検出することができる。
そして、この検出されたノイズ量が基準量より多い場合
だけ、ノイズキャンセラ回路でノイズ成分を抑圧した輝
度信号と、低域変換した色信号とを混合したビデオ信号
を磁気テープに記録するので、この磁気テープから再生
すると、ノイズの少ない画面が得られる。[Operation] Since the amount of noise in the luminance signal is detected during the horizontal synchronization period, the amount of noise can be detected without being affected by changes in the image signal of the luminance signal. Then, only when the detected amount of noise is greater than the reference amount, a video signal is recorded on the magnetic tape, which is a mixture of the luminance signal whose noise component has been suppressed by the noise canceler circuit and the color signal which has been converted to low frequency. Playing back from tape provides a screen with less noise.
【０００７】[0007]
【実施例】図１は、本発明の一実施例のブロック回路図
である。図において、９はノイズ検知回路、１０はノイ
ズキャンセラ回路、１１は切換スイッチで、ノイズキャ
ンセラ回路１０は、ハイパスフィルタ（ＨＰＦ）１２，
リミッタ回路１３，極性反転回路１４および合成回路１
５で構成されている。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block circuit diagram of an embodiment of the present invention. In the figure, 9 is a noise detection circuit, 10 is a noise canceller circuit, 11 is a changeover switch, and the noise canceler circuit 10 is a high pass filter (HPF) 12,
Limiter circuit 13, polarity inversion circuit 14 and synthesis circuit 1
It consists of 5.
【０００８】次に、動作を説明する。ＹＣ分離回路１で
分離された輝度信号Ｙは、ノイズ検知回路９と、ノイズ
キャンセラ回路１０に入力される。図２は、ノイズ検知
回路９を示す図、図３は、その各部の信号波形図である
。図２において、クランプされて同期信号が一定の直流
電位になっている輝度信号Ｙ（図３（ａ））は、Ｔｒ１
，Ｔｒ２によって水平同期期間の信号ｂ（図３（ｂ））
が抽出される。この信号ｂは、Ｃ２ とＲ４，Ｒ５ で
構成されたハイパスフィルタによってノイズの高域成分
Ｃ（図３（ｃ））のみがとり出される。この高域成分Ｃ
はＴｒ３で増幅され、Ｔｒ４とＣ４ によって検波され
て、ノイズ成分の量に応じたレベルの図３（ｄ）に示す
波形の直流電圧信号ｄが得られる。Next, the operation will be explained. The luminance signal Y separated by the YC separation circuit 1 is input to a noise detection circuit 9 and a noise canceller circuit 10. FIG. 2 is a diagram showing the noise detection circuit 9, and FIG. 3 is a signal waveform diagram of each part thereof. In FIG. 2, the luminance signal Y (FIG. 3(a)) whose synchronization signal is clamped at a constant DC potential is Tr1
, Tr2, the horizontal synchronization period signal b (Fig. 3(b))
is extracted. From this signal b, only the high-frequency component C of noise (FIG. 3(c)) is extracted by a high-pass filter composed of C2, R4, and R5. This high frequency component C
is amplified by Tr3, detected by Tr4 and C4, and a DC voltage signal d having a waveform shown in FIG. 3(d) with a level corresponding to the amount of noise components is obtained.
【０００９】この直流電圧信号ｄは、水平同期信号によ
って切り換えられるＳｗ１によつて水平同期期間の信号
成分のみが取り出され、Ｃ５ ，Ｔｒ５でサンプルホー
ルドされて、ノイズの量に応じた、連続した直流出力電
圧ｅ（図（ｅ））が出力される。このようにして得られ
た検波出力ｅを、Ｒ１１，Ｃ６ で積分して安定させ、
コンパレータＣｏｍ１で基準電位と比較し、その電位よ
り直流電位ｅの方が高い場合には“Ｌ”レベル、低い場
合には“Ｈ”レベルとなるスイッチ切換信号ｆを出力す
る。From this DC voltage signal d, only the signal component of the horizontal synchronization period is taken out by Sw1 which is switched by the horizontal synchronization signal, and sampled and held by C5 and Tr5 to generate a continuous DC voltage signal according to the amount of noise. An output voltage e (figure (e)) is output. The detection output e obtained in this way is integrated and stabilized by R11 and C6,
A comparator Com1 compares the DC potential with a reference potential, and outputs a switch switching signal f which becomes an "L" level when the DC potential e is higher than the reference potential, and an "H" level when it is lower.
【００１０】図４は、本実施例のノイズキャンセラ回路
１０の一例を示すブロック回路図、図５は、その各部の
信号波形図である。ノイズの乗った入力輝度信号Ｙ（図
５（ａ））から、ハイパスフィルタ１２によってノイズ
を含んだ高域成分ｇを抽出し、リミッタ回路１３で高域
成分ｇ（図５（ｇ））の中でノイズより大きな信号部分
をカットし、極性反転回路１４でその信号の極性を反転
した信号ｈ（図５（ｈ））を得る。この信号ｈは、ほと
んどノイズ成分しか含まれていないので、合成回路１５
で、この信号ｈと入力輝度信号Ｙとを合成してノイズの
抑制された出力輝度信号Ｙ０ （図５（ｉ））を出力す
る。FIG. 4 is a block circuit diagram showing an example of the noise canceller circuit 10 of this embodiment, and FIG. 5 is a signal waveform diagram of each part thereof. The high-pass filter 12 extracts the noise-containing high-frequency component g from the noise-containing input luminance signal Y (FIG. 5(a)), and the limiter circuit 13 extracts the noise-containing high-frequency component g (FIG. 5(g)). The signal portion larger than the noise is cut off, and the polarity inversion circuit 14 inverts the polarity of the signal to obtain a signal h (FIG. 5(h)). Since this signal h contains almost only noise components, the synthesis circuit 15
Then, this signal h and the input luminance signal Y are combined to output the noise-suppressed output luminance signal Y0 (FIG. 5(i)).
【００１１】切換スイッチ１１は、スイッチ切換信号ｆ
が“Ｈ”レベルのときはａ端子側に切り換えられて、Ｙ
Ｃ分離回路１から入力された輝度信号ＹをＦＭ復調器３
に入力し、“Ｌ”レベルのときはｂ端子側に切り換えら
れて、ノイズキャンセラ回路１０から入力された輝度信
号Ｙ０ をＦＭ復調器３に入力する。この結果、ＹＣ分
離回路１から出力される輝度信号Ｙに含まれているノイ
ズの量が、コンパレータＣｏｍ１における基準電位によ
って定まる量より多いときは、自動的に、ノイズキャン
セラ回路１０でノイズが抑圧された輝度信号Ｙ０ が磁
気テープ８に記録されるので、この磁気テープ８から再
生された輝度信号には、ノイズの少ないビデオ信号が得
られる。The changeover switch 11 receives a switch changeover signal f
When is at “H” level, it is switched to the a terminal side and Y
The luminance signal Y input from the C separation circuit 1 is sent to the FM demodulator 3.
When it is at the "L" level, it is switched to the b terminal side, and the luminance signal Y0 input from the noise canceller circuit 10 is input to the FM demodulator 3. As a result, when the amount of noise contained in the luminance signal Y output from the YC separation circuit 1 is greater than the amount determined by the reference potential in the comparator Com1, the noise is automatically suppressed by the noise canceller circuit 10. Since the luminance signal Y0 is recorded on the magnetic tape 8, the luminance signal reproduced from the magnetic tape 8 provides a video signal with less noise.
【００１２】なお、図２に示したノイズ検知回路９、お
よび図４に示したノイズキャンセラ回路１０は、この構
成に限られるものでないことはいうまでもない。It goes without saying that the noise detection circuit 9 shown in FIG. 2 and the noise canceller circuit 10 shown in FIG. 4 are not limited to this configuration.
【００１３】[0013]
【発明の効果】本発明によれば、記録しようとする入力
ビデオ信号が、ノイズの多いものであるときは、自動的
に、ノイズキャンセラ回路を通してノイズを抑圧したビ
デオ信号を磁気テープに記録し、ノイズの少ないもので
あるときは、そのまま記録するようにしたので、当該磁
気テープをＶＴＲで再生したとき、画質調整しなくても
ノイズの少ない再生画面が得られる効果がある。According to the present invention, when the input video signal to be recorded has a lot of noise, the video signal with noise suppressed through the noise canceler circuit is automatically recorded on the magnetic tape, and the noise is eliminated. When the magnetic tape has a small amount of noise, it is recorded as is, so that when the magnetic tape is played back on a VTR, a playback screen with less noise can be obtained without adjusting the image quality.
【図１】本発明の一実施例のブロック回路図である。FIG. 1 is a block circuit diagram of an embodiment of the present invention.
【図２】本実施例のノイズ検知回路のブロック回路図で
ある。FIG. 2 is a block circuit diagram of the noise detection circuit of this embodiment.
【図３】このノイズ検知回路の各部の信号波形図である
。FIG. 3 is a signal waveform diagram of each part of this noise detection circuit.
【図４】本実施例のノイズキャンセラ回路のブロック回
路図である。FIG. 4 is a block circuit diagram of the noise canceller circuit of this embodiment.
【図５】このノイズキャンセラ回路の各部の信号波形図
である。FIG. 5 is a signal waveform diagram of each part of this noise canceller circuit.
【図６】従来のＶＴＲの記録系のブロック回路図である
。FIG. 6 is a block circuit diagram of a recording system of a conventional VTR.
１ ＹＣ分離回路 ３ ＦＭ変調器 ４ 混合回路 ７ 記録ヘッド ８ 磁気テープ ９ ノイズ検知回路 １０ ノイズキャンセラ回路 １１ 切換スイッチ 1 YC separation circuit 3 FM modulator 4 Mixed circuit 7 Recording head 8 Magnetic tape 9 Noise detection circuit 10 Noise canceller circuit 11 Selector switch
Claims (1)
分離するＹＣ分離回路と、この分離された輝度信号のノ
イズ成分を除去するノイズキャンセラ回路と、上記ＹＣ
分離回路の出力輝度信号または上記ノイズキャンセラ回
路の出力信号を選択して出力する切換スイッチと、上記
輝度信号の水平同期信号期間のノイズ量を検出し、この
検出したノイズ量が基準量より多いときは上記ノイズキ
ャンセラ回路の出力輝度信号を選択し、少ないときは上
記ＹＣ分離回路で分離された輝度信号を選択するように
上記切換スイッチを制御する切換信号を出力するノイズ
検知回路とを備え、上記切換スイッチの出力信号と上記
ＹＣ分離回路で分離された色信号を低域変換した信号と
を混合して磁気テープに記録するように構成されてなる
磁気記録再生装置。1. A YC separation circuit that separates an input video signal into a luminance signal and a color signal, a noise canceller circuit that removes noise components from the separated luminance signal, and a YC separation circuit that removes a noise component from the separated luminance signal.
A changeover switch selects and outputs the output luminance signal of the separation circuit or the output signal of the noise canceller circuit, and detects the amount of noise in the horizontal synchronization signal period of the luminance signal, and when the detected amount of noise is greater than the reference amount. a noise detection circuit that outputs a switching signal that controls the changeover switch to select the output brightness signal of the noise canceller circuit and select the brightness signal separated by the YC separation circuit when there is less, the changeover switch A magnetic recording/reproducing device configured to mix the output signal of the above and a signal obtained by low-frequency conversion of the color signal separated by the YC separation circuit and record the mixture on a magnetic tape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3060174A JPH04313980A (en) | 1991-03-25 | 1991-03-25 | Magnetic recording and reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3060174A JPH04313980A (en) | 1991-03-25 | 1991-03-25 | Magnetic recording and reproducing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04313980A true JPH04313980A (en) | 1992-11-05 |
Family
ID=13134531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3060174A Pending JPH04313980A (en) | 1991-03-25 | 1991-03-25 | Magnetic recording and reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04313980A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5956095A (en) * | 1996-05-30 | 1999-09-21 | Matsushita Electric Industrial Co., Ltd. | Noise suppression apparatus |
-
1991
- 1991-03-25 JP JP3060174A patent/JPH04313980A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5956095A (en) * | 1996-05-30 | 1999-09-21 | Matsushita Electric Industrial Co., Ltd. | Noise suppression apparatus |
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