JPH04132481A - Video signal processing unit - Google Patents
Video signal processing unitInfo
- Publication number
- JPH04132481A JPH04132481A JP2255774A JP25577490A JPH04132481A JP H04132481 A JPH04132481 A JP H04132481A JP 2255774 A JP2255774 A JP 2255774A JP 25577490 A JP25577490 A JP 25577490A JP H04132481 A JPH04132481 A JP H04132481A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- video signal
- circuit
- noise
- switching
- 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
- 230000001360 synchronised effect Effects 0.000 claims abstract description 4
- 230000001934 delay Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 101710162453 Replication factor A Proteins 0.000 description 1
- 102100035729 Replication protein A 70 kDa DNA-binding subunit Human genes 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
Landscapes
- Picture Signal Circuits (AREA)
- Television Signal Processing For Recording (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、映像信号を記録再生する磁気記録再生装置に
おける映像信号処理に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to video signal processing in a magnetic recording and reproducing apparatus for recording and reproducing video signals.
従来の技術
映像信号を周波数変調し、1フィールド毎に異なる第1
.第2の磁気ヘッドによって記録再生する磁気記録再生
装置における映像信号の再生系の従来のブロック図を第
3図に示す。1.2は磁気ヘッド、3は切り換え回路、
4は周波数復調回路、5はローパスフィルタ、8は切り
換え信号発生装置である。前記の映像磁気記録再生装置
の動作を説明する。磁気記録媒体に記録された映像周波
数被変調波信号(以下RF倍信号略す)を、磁気ヘッド
1,2により再生し、その出力を切り換え回路3により
1フィールド毎に切り換え周波数復調回路4に出力する
。切り換え回路3は切り換え信号発生袋W8より供給さ
れる切り換え信号によって1フィールド毎に切り換わる
。周波数復調回路4は供給されたRF倍信号映像信号に
復調し、ローパスフィルタ5へ出力する。ローパスフィ
ルタ5では搬送波の2倍周波数成分を除去する。Conventional technology The video signal is frequency modulated, and the first
.. FIG. 3 shows a conventional block diagram of a video signal reproducing system in a magnetic recording and reproducing apparatus that performs recording and reproducing using a second magnetic head. 1.2 is a magnetic head, 3 is a switching circuit,
4 is a frequency demodulation circuit, 5 is a low-pass filter, and 8 is a switching signal generator. The operation of the above-mentioned video magnetic recording and reproducing apparatus will be explained. A video frequency modulated wave signal (hereinafter referred to as RF multiplied signal) recorded on a magnetic recording medium is reproduced by magnetic heads 1 and 2, and the output thereof is outputted to a switching frequency demodulation circuit 4 by a switching circuit 3 for each field. . The switching circuit 3 is switched for each field by a switching signal supplied from a switching signal generating bag W8. The frequency demodulation circuit 4 demodulates the supplied RF multiplied signal video signal and outputs it to the low-pass filter 5. The low-pass filter 5 removes the double frequency component of the carrier wave.
発明が解決しようとする課題
このような従来の再生系では、切り換え回路3の切り換
えの際にRF倍信号位相の不連続が生じ、モニタ画面下
部にノイズとなってあられれ、またジッタ成分により変
動するので、非常に目ざわりである。Problems to be Solved by the Invention In such a conventional reproduction system, discontinuity in the phase of the RF multiplied signal occurs when the switching circuit 3 switches, and noise appears at the bottom of the monitor screen, and fluctuations due to jitter components occur. Therefore, it is very noticeable.
課題を解決するための手段
本発明は、上記の目的を達成するために、映像信号を周
波数変調し1フィールド毎に異なる第1、第2の2つの
磁気ヘッドによって記録再生する磁気記録再生装置にお
いて、前記の第1.第2の磁気ヘッドと、第1.第2の
磁気ヘッドの出力信号を切り換える第1の切り換え回路
と、前記の切り換え回路を制御する切り換え信号発生装
置と、周波数復調回路と、ローパスフィルタと、1水平
同期期間遅延する遅延回路と第2切り換え回路と、第2
の切り換え回路を制御する信号発生装置を有し、第1の
制御信号と第2の制御信号が同期していることを特徴と
する。Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a magnetic recording and reproducing apparatus that frequency-modulates a video signal and records and reproduces it using two different first and second magnetic heads for each field. , the above-mentioned No. 1. a second magnetic head; a first switching circuit that switches the output signal of the second magnetic head, a switching signal generator that controls the switching circuit, a frequency demodulation circuit, a low-pass filter, a delay circuit that delays by one horizontal synchronization period, and a second switching circuit that switches the output signal of the second magnetic head. a switching circuit and a second
The present invention is characterized in that the first control signal and the second control signal are synchronized.
作用
本発明は上記した構成により、再生RF信号を1フィー
ルドごとに切り換える際に生しるRF倍信号位相の不連
続に起因する映像信号のノイズ部分を、1水平同期期間
前のそれに相当する部分で置き換えるものである。Effect of the Invention With the above-described configuration, the present invention replaces the noise portion of the video signal caused by the discontinuity of the RF multiplied signal phase that occurs when switching the reproduced RF signal for each field by converting it into a portion corresponding to that one horizontal synchronization period before. It is replaced by .
実施例
以下、本発明の一実施例について第1図および第2図を
参照しながら説明する。第1図において、磁気ヘッド1
.2で磁気記録媒体に記録されたRF倍信号再生し、こ
のRF倍信号1フィールド毎に切り換え回路3で切り換
える。切り換え回路3は制御信号発生装置8で制御され
る。この出力を周波数復調回路4で映像信号に復調し、
ローパスフィルタ5で搬送波の2倍の周波数成分を除去
する。この映像信号を1水平同期期間遅延する遅延回路
6と切り換え回路7で構成される回路を通過してモニタ
(図示せず)に出力する。この切り換え回路7は制御信
号発生装置9によって制御され、制御信号発生装置9の
信号は制御信号発生装置8の信号と同期している。EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2. In FIG. 1, a magnetic head 1
.. 2, the RF multiplied signal recorded on the magnetic recording medium is reproduced, and the switching circuit 3 switches the RF multiplied signal every field. The switching circuit 3 is controlled by a control signal generator 8. This output is demodulated into a video signal by the frequency demodulation circuit 4,
A low-pass filter 5 removes frequency components twice the carrier wave. This video signal passes through a circuit consisting of a delay circuit 6 that delays one horizontal synchronization period and a switching circuit 7, and is output to a monitor (not shown). This switching circuit 7 is controlled by a control signal generator 9, and the signal of the control signal generator 9 is synchronized with the signal of the control signal generator 8.
上記の構成において動作を説明する。磁気ヘッド1.2
で磁気記録媒体よりRF倍信号再生し第2図の(a)の
ような制御信号で切り換え回路3を切り換えると、RF
倍信号C1に位相の不連続Aを生じる。このRF倍信号
周波数復調回路4で映像信号に復調すると(dlのよう
にノイズBを含んだものとなる。telはローパスフィ
ルタ5を通過するため(clよりローパスフィルタ5の
遅延時間τだけ遅延したものである。制御信号発生装置
では制御信号第2図(alの立ち上がりと立ち下がりの
エツジに同期し第2図(blに示すような幅1 (1>
τ)の制御信号を発生し、切り換え回路7を制御する。The operation in the above configuration will be explained. magnetic head 1.2
When the RF multiplied signal is reproduced from the magnetic recording medium and the switching circuit 3 is switched with a control signal as shown in FIG. 2(a), the RF
A phase discontinuity A occurs in the doubled signal C1. When demodulated into a video signal by this RF double signal frequency demodulation circuit 4, it becomes a video signal (like dl that includes noise B). Since tel passes through the low-pass filter 5 (it is delayed from cl by the delay time τ of the low-pass filter 5) The control signal generator generates a width 1 (1>
τ) to control the switching circuit 7.
切り換え回路7には第2図telに示すようなローパス
フィルタ5の出力信号と第2図げ)に示すようなローパ
スフィルタ5の出力信号を遅延回路6によって1水平同
期期間遅延された信号が供給されている。The switching circuit 7 is supplied with the output signal of the low-pass filter 5 as shown in FIG. 2 and a signal obtained by delaying the output signal of the low-pass filter 5 as shown in FIG. has been done.
切り換え回路7は前記第2図(blに示す制御信号によ
って制御されるので、その出力信号は第2図tg+に示
すようなノイズ部分が1水平同期期間前の映像信号で置
き換えられたノイズBのない映像信号となる。Since the switching circuit 7 is controlled by the control signal shown in FIG. 2 (bl), its output signal is the noise B shown in FIG. The result will be a video signal that does not match.
このように本発明の実施例の映像信号処理装置によれば
、ノイズ部分の映像信号を1水平同期期間前の相当部分
に置き換えることで、ノイズのない映像信号が得られる
。As described above, according to the video signal processing device according to the embodiment of the present invention, a noise-free video signal can be obtained by replacing the noise portion of the video signal with a portion corresponding to one horizontal synchronization period earlier.
発明の効果
以上の説明から明らかなように、本発明によれば、磁気
ヘッド出力切り換えの際に生しるRF倍信号位相の不連
続が原因となる映像信号のノイズを1水平同期期間前の
相当部分の映像信号と置き換えることにより除去できる
ので、大画面でもノイズのない良好な画面を得ることが
できる。Effects of the Invention As is clear from the above explanation, according to the present invention, the noise in the video signal caused by the discontinuity of the RF multiplied signal phase that occurs when switching the magnetic head output is reduced one horizontal synchronization period before. Since the noise can be removed by replacing a considerable portion of the video signal, a good screen without noise can be obtained even on a large screen.
第1図は本発明の一実施例の映像信号処理装置の構成を
示すブロック図、第2図は装置の各部の信号波形、第3
図は従来の映像信号処理装置のブロック図である。
6・・・・・・1水平同期期間遅延回路、7・・・・・
・切り換え回路、9・・・・・・制御信号発生装置。
代理人の氏名 弁理士小鍜治明 はが2名第
図
第
図FIG. 1 is a block diagram showing the configuration of a video signal processing device according to an embodiment of the present invention, FIG. 2 shows signal waveforms of each part of the device, and FIG.
The figure is a block diagram of a conventional video signal processing device. 6...1 horizontal synchronization period delay circuit, 7...
-Switching circuit, 9...control signal generator. Name of agent: Patent attorney Haruaki Ogata
Claims (1)
第2の磁気ヘッドによって記録再生する磁気記録再生装
置において、前記の第1、第2の磁気ヘッドと、第1、
第2の磁気ヘッドの出力信号を切り換える第1の切り換
え回路と、前記の切り換え回路を制御する切り換え信号
発生装置と、周波数復調回路と、ローパスフィルタと、
1水平同期期間遅延する遅延回路と、第2の切り換え回
路と、第2の切り換える第1の切り換えと、前記の切り
換え回路を制御する切り換え信号発生装置とを有し、第
1の制御信号と第2の制御信号が同期していることを特
徴とする映像信号処理装置。The first frequency-modulated video signal is different for each field.
In a magnetic recording and reproducing device that performs recording and reproducing using a second magnetic head, the first and second magnetic heads;
a first switching circuit that switches the output signal of the second magnetic head, a switching signal generator that controls the switching circuit, a frequency demodulation circuit, and a low-pass filter;
It has a delay circuit that delays by one horizontal synchronization period, a second switching circuit, a first switching that switches the second, and a switching signal generator that controls the switching circuit, and includes a first control signal and a second switching circuit. A video signal processing device characterized in that two control signals are synchronized.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2255774A JPH04132481A (en) | 1990-09-25 | 1990-09-25 | Video signal processing unit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2255774A JPH04132481A (en) | 1990-09-25 | 1990-09-25 | Video signal processing unit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04132481A true JPH04132481A (en) | 1992-05-06 |
Family
ID=17283441
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2255774A Pending JPH04132481A (en) | 1990-09-25 | 1990-09-25 | Video signal processing unit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04132481A (en) |
-
1990
- 1990-09-25 JP JP2255774A patent/JPH04132481A/en active Pending
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