JPH0519224B2 - - Google Patents
Info
- Publication number
- JPH0519224B2 JPH0519224B2 JP57149100A JP14910082A JPH0519224B2 JP H0519224 B2 JPH0519224 B2 JP H0519224B2 JP 57149100 A JP57149100 A JP 57149100A JP 14910082 A JP14910082 A JP 14910082A JP H0519224 B2 JPH0519224 B2 JP H0519224B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- signal
- modulated
- audio signal
- video signal
- 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 - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/76—Television signal recording
- H04N5/91—Television signal processing therefor
- H04N5/92—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback
- H04N5/9201—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving the multiplexing of an additional signal and the video signal
- H04N5/9202—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving the multiplexing of an additional signal and the video signal the additional signal being a sound signal
- H04N5/9204—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving the multiplexing of an additional signal and the video signal the additional signal being a sound signal using frequency division multiplex
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/02—Analogue recording or reproducing
- G11B20/06—Angle-modulation recording or reproducing
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Television Signal Processing For Recording (AREA)
- Optical Recording Or Reproduction (AREA)
Description
【発明の詳細な説明】
本発明はビデオデイスクに映像および音声信号
を記録する記録方式に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording method for recording video and audio signals on a video disc.
従来の変調システムは、第１図に示す如く、入
力映像信号をFM変調器１によつてFM変調し、
入力オーデイオ信号をFM変調器２によつてFM
変調して、FM変調器１の出力信号とFM変調器
２の出力信号とを加算回路３によつて加算し、加
算回路３の出力信号をリミツタ４により振幅制限
する信号処理を行なつている。 As shown in FIG. 1, the conventional modulation system performs FM modulation on an input video signal using an FM modulator 1.
The input audio signal is converted to FM by FM modulator 2.
The output signal of the FM modulator 1 and the output signal of the FM modulator 2 are added by an adder circuit 3, and the output signal of the adder circuit 3 is amplitude-limited by a limiter 4. .
しかるにFM変調器１によりFM変調されたビ
デオRF信号の復調に必要な帯域は、変調指数が
１以下のため、被変調周波数の最高周波数による
１次側波帯が占める帯域（3.9〜13.5MHz）であ
る。このためオーデイオサブキヤリヤは１次側波
帯の影響を受けないように2.3及び2.8MHzに設定
されている。しかして、ビデオデイスクにおいて
はオーデイオ信号をパルス幅変調方式で多重化し
ているため、FM変調器２のキヤリヤレベルはビ
デオキヤリヤレベルの1/10程度にして混合してい
る。しかしリミツタにおいてさらに6dB低下す
る。このためビデオRF信号の２次側波帯のレベ
ルは１次側波帯に比較して低いが、オーデイオ
RF信号はビデオRF信号の高次、特に２次側波帯
による妨害を受けて、オーデイオRF信号のＳ／
Ｎおよび音質を悪化させる欠点があつた。 However, since the modulation index is less than 1, the band required for demodulating the video RF signal FM modulated by the FM modulator 1 is the band occupied by the primary sideband of the highest frequency of the modulated frequency (3.9 to 13.5 MHz). It is. For this reason, the audio subcarrier is set to 2.3 and 2.8MHz so as not to be affected by the primary sideband. However, since audio signals are multiplexed using a pulse width modulation method in a video disc, the carrier level of the FM modulator 2 is set to about 1/10 of the video carrier level for mixing. However, in the limiter, it is further reduced by 6 dB. Therefore, the level of the secondary sideband of the video RF signal is lower than that of the primary sideband, but the level of the secondary sideband of the video RF signal is lower than that of the primary sideband.
The RF signal is interfered with by the higher orders of the video RF signal, especially the secondary sideband, and the S/S of the audio RF signal.
There were drawbacks such as deterioration of N and sound quality.
本発明は上記にかんがみなされたもので、上記
の欠点を解消した記録媒体の記録方式を提供する
ことを目的とするものである。 The present invention has been made in view of the above, and an object of the present invention is to provide a recording method for a recording medium that eliminates the above-mentioned drawbacks.
以下、本発明を実施例により説明する。 The present invention will be explained below with reference to Examples.
第２図は本発明の一実施例を示すブロツク図で
ある。 FIG. 2 is a block diagram showing one embodiment of the present invention.
本発明の一実施例においては、第１図に示した
従来の変調システムにおいてさらにFM変調器１
と加算器３との間に、オーデイオRF帯域成分を
除去するノツチフイルタ５が接続してある。 In one embodiment of the present invention, the conventional modulation system shown in FIG.
A notch filter 5 is connected between the adder 3 and the adder 3 for removing audio RF band components.
そこでFM変調器１により変調されたビデオ
RF信号の帯域中の高次側波帯成分のうちオーデ
イオRF帯域内に入る成分はノツチフイルタ５に
より除去される。したがつて従来の欠点は解消す
る。 So the video modulated by FM modulator 1
Among the high-order sideband components in the RF signal band, the components falling within the audio RF band are removed by the notch filter 5. Therefore, the conventional drawbacks are eliminated.
これは、FM変調器１で変調されたビデオRF
信号の帯域は１次側波帯が通過する帯域を確保す
れば充分であるためであつて、第３図ａに示す
FM変調器１のビデオRF信号は、ノツチフイル
タ５によりその第２次下側側波帯成分が除去され
て第３図ｂに示す如くになる。 This is the video RF modulated by FM modulator 1.
This is because it is sufficient to secure the signal band through which the primary sideband passes, as shown in Figure 3a.
The video RF signal of the FM modulator 1 has its secondary lower sideband component removed by the notch filter 5, and becomes as shown in FIG. 3b.
そこでノツチフイルタ５の出力信号とFM変調
器２から出力されるオーデイオRF信号とが加算
器３で加算され、リミツタ４でオーデイオRF信
号がパルス幅変調で多重化され、リミツタ４で振
幅制限されて、リミツタ４の出力信号の周波数分
布は第３図ｃに示す如くノツチフイルタ５にて除
去された帯域にオーデイオRF信号が位置するこ
とになり、オーデイオRF信号帯域内に入るビデ
オRF信号成分は無くなる。この場合に、ビデオ
RF信号はノツチフイルタ５による伝送系によつ
て振幅歪および位相歪が生じ、復調ビデオ信号に
歪を発生させるが、フイルタ５にノツチフイルタ
を用いることによつて、画質の低下を最小限にす
ることが可能である。 Therefore, the output signal of the notch filter 5 and the audio RF signal output from the FM modulator 2 are added in the adder 3, the audio RF signal is multiplexed by pulse width modulation in the limiter 4, and the amplitude is limited in the limiter 4. As shown in FIG. 3c, the frequency distribution of the output signal of the limiter 4 is such that the audio RF signal is located in the band removed by the notch filter 5, and no video RF signal component falls within the audio RF signal band. In this case, the video
Amplitude distortion and phase distortion occur in the RF signal due to the transmission system using the notch filter 5, which causes distortion in the demodulated video signal. However, by using a notch filter as the filter 5, the deterioration in image quality can be minimized. It is possible.
またビデオRF信号中の上側波帯は除去してい
ないために、リミツタ４の出力信号中に下側波帯
がオーデイオRF信号帯域に現われるが、これは
抑圧されている。さらに、ノツチフイルタ５の減
衰率をオーデイオRF帯域に発生するビデオRF信
号の高調波の量に比例して変化させるようにする
ことも可能である。このように構成することによ
り、オーデイオRF信号への妨害量に応じた制御
が可能となる。 Furthermore, since the upper sideband in the video RF signal is not removed, a lower sideband appears in the audio RF signal band in the output signal of the limiter 4, but this is suppressed. Furthermore, it is also possible to change the attenuation rate of the notch filter 5 in proportion to the amount of harmonics of the video RF signal generated in the audio RF band. With this configuration, control can be performed according to the amount of interference to the audio RF signal.
本発明は、周波数変調オーデイオ信号帯域に落
ちる周波数変調ビデオ信号の２次の下側波帯成分
をノツチフイルタによつて抑圧低減した後にこの
周波数変調ビデオ信号と周波数変調オーデイオ信
号とを周波数多重するようにしたので、ハイパス
フイルタやバンドパスフイルタでは除去できなか
つた周波数変調オーデイオ信号帯域に落ちる周波
数変調ビデオ信号成分を除去することができ、こ
れによつてオーデイオ信号のＳ／Ｎや音質が改善
されて忠実な音声再生を行うことができるという
格別の効果が得られるものである。 The present invention uses a notch filter to suppress and reduce the secondary lower sideband components of a frequency modulated video signal falling in the frequency modulated audio signal band, and then frequency-multiplexes the frequency modulated video signal and the frequency modulated audio signal. Therefore, it is possible to remove the frequency modulated video signal components that fall in the frequency modulated audio signal band, which could not be removed by high pass filters or band pass filters. This improves the S/N and sound quality of the audio signal and increases the fidelity. This provides a special effect of being able to reproduce sound.
第１図は従来の変調システムのブロツク図、第
２図は本発明の一実施例のブロツク図、第３図は
本発明の一実施例の作用の説明に供する周波数ス
ペクトラムである。
１……FM変調器、２……RM変調器、３……
加算器、４……リミツタ、５……ノツチフイル
タ。
FIG. 1 is a block diagram of a conventional modulation system, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a frequency spectrum for explaining the operation of an embodiment of the present invention. 1...FM modulator, 2...RM modulator, 3...
Adder, 4...limiter, 5...notch filter.
Claims (1)
変調して１次の側波帯が占める帯域が3.9〜
13.5MHzの範囲を有する周波数変調ビデオ信号を
発生させると共に、2.3MHzおよび2.8MHzの搬送
波をオーデイオ信号でそれぞれ周波数変調して周
波数変調ビデオ信号より充分低い搬送波レベルの
周波数変調オーデイオ信号を発生させることによ
つてこの周波数変調オーデイオ信号が周波数変調
ビデオ信号の１次の下側波帯より低い帯域を占め
るようにし、これらの周波数変調された信号を周
波数多重して記録媒体に記録するようにした記録
方式において、 前記周波数変調ビデオ信号から前記周波数変調
オーデイオ信号と重なる２次の下側波帯成分をノ
ツチフイルタにより抑圧低減した後、前記周波数
変調オーデイオ信号と周波数多重するようにした
ことを特徴とする記録媒体の記録方式。[Scope of Claims] 1. Frequency modulation of a video signal containing a color signal component in the high frequency range so that the band occupied by the first-order sideband is 3.9 to 3.9.
A frequency modulated video signal having a range of 13.5 MHz is generated, and a carrier wave of 2.3 MHz and 2.8 MHz is frequency modulated with an audio signal to generate a frequency modulated audio signal having a carrier wave level sufficiently lower than that of the frequency modulated video signal. Therefore, a recording method in which this frequency-modulated audio signal occupies a band lower than the primary lower sideband of the frequency-modulated video signal, and these frequency-modulated signals are frequency-multiplexed and recorded on a recording medium. A recording medium characterized in that the secondary lower sideband component overlapping with the frequency modulated audio signal is suppressed and reduced from the frequency modulated video signal by a notch filter, and then frequency multiplexed with the frequency modulated audio signal. recording method.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57149100A JPS5940308A (en) | 1982-08-30 | 1982-08-30 | Modulating system of video disk recorder |
| DE8383304991T DE3381815D1 (en) | 1982-08-30 | 1983-08-30 | VIDEO DISK RECORDING AND PLAYBACK SYSTEM. |
| EP19830304991 EP0107295B1 (en) | 1982-08-30 | 1983-08-30 | Video disc type recording and reproducing system |
| US06/527,721 US4683502A (en) | 1982-08-30 | 1983-08-30 | Video disc type recording and reproducing system with interference reduction filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57149100A JPS5940308A (en) | 1982-08-30 | 1982-08-30 | Modulating system of video disk recorder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5940308A JPS5940308A (en) | 1984-03-06 |
| JPH0519224B2 true JPH0519224B2 (en) | 1993-03-16 |
Family
ID=15467693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57149100A Granted JPS5940308A (en) | 1982-08-30 | 1982-08-30 | Modulating system of video disk recorder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5940308A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0634297B2 (en) * | 1985-11-06 | 1994-05-02 | 三洋電機株式会社 | Frequency multiplexing circuit for optical video disc recorder |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5550788A (en) * | 1978-10-06 | 1980-04-12 | Hitachi Ltd | Cross talk reduction device |
| JPS56144690A (en) * | 1980-04-14 | 1981-11-11 | Matsushita Electric Ind Co Ltd | Recording system for video signal |
-
1982
- 1982-08-30 JP JP57149100A patent/JPS5940308A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5940308A (en) | 1984-03-06 |
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