JPS63240276A - Television signal demodulator - Google Patents

Abstract

PURPOSE:To obtain multiplexed information without transmission distortion by inverting the phase of a subcarrier at each frame and each horizontal scanning period to attain a signal subjected to phase control to be in-phase after 263 horizontal scanning periods. CONSTITUTION:The subcarrier is controlled by a phase controller 15 in a way that its phase is inverted for one horizontal scanning period each or for one field or for one frame. The signal subjected to frequency conversion by the subcarrier having the phase as above is given to a modulator 11. A carrier P1 obtained from an oscillator 9 is modulated in terms of amplitude by an amplitude modulator 7 by using an output signal of an adder 6. The amplitude modulation wave obtained in this way is subjected to band limit by a 1st filter 8 to obtain a residual-side band and the result is fed to an adder 13. The carrier P1 obtained from the oscillator 9 is shifted in terms of phase by 90 deg. at a phase shifter 10 as a carrier P2. The signal modulated by the modulator 11 is subjected to band limit by a 2nd filter 12 and fed to the adder 13. The output of the adder 13 becomes a synthesized television signal.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、現行のテレビジョン放送信号に別の信号を多
重伝送した信号を復調するテレビジョン信号復調装置に
関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television signal demodulation device that demodulates a signal obtained by multiplexing and transmitting a current television broadcast signal with another signal.

従来の技術 我が国の現在のＮＴＳＣ［ナショナル　テレビジョン　
システム　コミッティ（Ｎａｔｉｏｎａｌ　Ｔｅ１ｅ−
ｖｉｓｉｏｎ　Ｓｙｓｔｅｍ　Ｃｏｍｍ１ｔｔｅｅ　）
　］方式によるカラーテレビジョン放送が昭和３５年に
開始されて以来、２５年以上が経過した。その間、高精
細な画面に対する要求と、テレビジョン受信機の性能向
上に伴い、各種の新しいテレビジョン方式が提案されて
いる。また、→ノーービスされる番組の内容自体も単な
るスタジオ番組や中継番組などから、シネマサイズの映
画の放送など、より高画質で臨場窓を伴う映像を有する
番組へと変化してきている。Conventional technology Japan's current NTSC [National Television
System Committee (National Te1e-
vision system comm1tee)
] More than 25 years have passed since color television broadcasting began in 1960. In the meantime, various new television systems have been proposed in response to demands for high-definition screens and improvements in the performance of television receivers. In addition, the content of the programs that are broadcast on no-bis is changing from simple studio programs and relay programs to programs that have higher quality images with realistic windows, such as cinema-sized movie broadcasts.

現行放送は、走査線数５２５本、２；１飛越走査、輝度
信号水平帯域幅４．２Ｍ１ｌｚ、アスペクト比４：３と
いう諸仕様（例えば、文献放送技術多書　カラーテレビ
ジョン　日本放送協会編、日本放送出版協会、１９６１
年、参照）を有しているが、このような背景のもとで現
行放送との両立性及び、水平解像度の向上を図ったテレ
ビジョン信号構成方法が提案されている。−例を以下に
述べる。（例えば、特願昭６１−１８０３３３号） 第４図は、送信側でのテレビジョン信号合成装置を示す
ブロック図である。輝度信号の高域成分を多重伝送する
ものとする。５１は搬送色信号入力端子、５２は輝度信
号入力端子、５３は第１フイルタ、５４は第２フイルタ
、５５は周波数変換器、５６は加算器、５７は振幅変調
器、５８は第３フイルタ、５９は発振器、６０は移相器
、６１は変調器、６２は第４フイルタ、６３は加算器、
６４は合成テレビジョン信号出力端子である。入力端子
５２から入力される輝度信号は、第１フイルタ５３及び
第２フイルタ５４に入力される。第２フイルタ５４で帯
域制限された輝度信号の高域成分は、周波数変換器５５
で低域に周波数変換される。第１フイルタ５３の出力は
、加算器５６で入力端子５１に入力される搬送色信号と
加算される。Current broadcasting has specifications such as the number of scanning lines: 525, 2:1 interlaced scanning, luminance signal horizontal bandwidth: 4.2M1lz, and aspect ratio: 4:3 (for example, the literature broadcasting technology multibook, Color Television, edited by Japan Broadcasting Corporation, Japan) Broadcast Publishing Association, 1961
However, against this background, a method for configuring television signals has been proposed that is compatible with current broadcasting and improves horizontal resolution. - Examples are given below. (For example, Japanese Patent Application No. 61-180333) FIG. 4 is a block diagram showing a television signal synthesis device on the transmitting side. It is assumed that the high-frequency components of the luminance signal are multiplexed and transmitted. 51 is a carrier color signal input terminal, 52 is a luminance signal input terminal, 53 is a first filter, 54 is a second filter, 55 is a frequency converter, 56 is an adder, 57 is an amplitude modulator, 58 is a third filter, 59 is an oscillator, 60 is a phase shifter, 61 is a modulator, 62 is a fourth filter, 63 is an adder,
64 is a composite television signal output terminal. The luminance signal input from the input terminal 52 is input to the first filter 53 and the second filter 54. The high frequency component of the luminance signal band-limited by the second filter 54 is transferred to a frequency converter 55.
The frequency is converted to a lower frequency range. The output of the first filter 53 is added to the carrier color signal input to the input terminal 51 by an adder 56.

加算器５６の出力である映像ベースバンド信号で、発振
器５９から得られる搬送波Ｐ１を振幅変調器５７により
振幅変調する。得られた信号を第３フイルタ５８で帯域
制限し残留側波帯にした後に加算器６３に加える。発振
器５９から得られる搬送波Ｐ、を移相器６０により９０
°位相シフトさせたものを搬送波Ｐ２とする。周波数変
換器５５で周波数変換された信号で、搬送波Ｐ２を搬送
波除去両側波帯振幅変調する。変調された信号を第４フ
イルタ６２で帯域制限した後に加算器６３に加える。加
算器６３の出力が合成テレビジョン信号となる。すなわ
ち映像ベースバンド信号に輝度信号の高域成分が重畳さ
れて合成テレビジョン信号となる。The carrier wave P1 obtained from the oscillator 59 is amplitude-modulated by the amplitude modulator 57 using the video baseband signal output from the adder 56. The obtained signal is band-limited by a third filter 58 to form a residual sideband, and then added to an adder 63. The carrier wave P obtained from the oscillator 59 is shifted to 90 by the phase shifter 60.
The phase-shifted wave is defined as carrier wave P2. The carrier wave P2 is subjected to carrier removal double-sided band amplitude modulation using the frequency-converted signal by the frequency converter 55. The modulated signal is band-limited by a fourth filter 62 and then added to an adder 63. The output of adder 63 becomes a composite television signal. That is, the high frequency component of the luminance signal is superimposed on the video baseband signal to form a composite television signal.

第５図は、受信側でのテレビジョン信号復調装置を示す
ブロック図である。７１はアンテナ、７２はチューナ、
７３は映像中間周波フィルタ、７４は映像検波器、７５
は搬送波再生回路、７６は輝度・色信号分離回路、７７
はフィルタ、７８は移相器、７９は多重信号検波器、８
０は周波数変換器、８１は加算器、８２は搬送色信号出
力端子、８３は輝度信号出力端子である。送信側から送
出された信号はアンテナ７１で受信され、チューナ７２
で中間周波数帯に周波数変換され、映像中間周波フィル
タ７３で帯域制限される。帯域制限された信号は、映像
検波器７４、搬送波再生回路７５に供給される。搬送波
再生回路７５では、同期検波用の搬送波ＩＩを再生する
。帯域制限された信号は、搬送波■１で映像検波器７４
において検波され、映像ベースバント°信号となる。映
像ベースバンド信号は、輝度・色信号分離回路７４で輝
度信号と搬送色信号に分離され、分離された１般送色信
号は出力端子８２に出力される。またチューナ７２の出
力はフィルタ７７で帯域制限する。搬送波再生回路７５
から得られる搬送波Ｉ、を移相器７８により送信装置側
で位相シフトさせた方向と同じ方向に９０°位相シフト
させた搬送波Ｉ２で、フィルタ７７の出力信号を多重信
号検波器７９において同期検波する。検波された信号は
周波数変換器８０で本来の周波数に変換され、輝度・色
信号分離回路７６で分離された輝度信号の低域成分と、
加算器８１で加算されて広帯域の輝度信号となり出力端
子８３に出力される。FIG. 5 is a block diagram showing a television signal demodulator on the receiving side. 71 is an antenna, 72 is a tuner,
73 is a video intermediate frequency filter, 74 is a video detector, 75
76 is a carrier wave regeneration circuit, 76 is a luminance/color signal separation circuit, and 77 is a carrier wave regeneration circuit.
is a filter, 78 is a phase shifter, 79 is a multiple signal detector, 8
0 is a frequency converter, 81 is an adder, 82 is a carrier color signal output terminal, and 83 is a luminance signal output terminal. A signal sent from the transmitting side is received by the antenna 71 and sent to the tuner 72.
The signal is frequency-converted to an intermediate frequency band by the video intermediate frequency filter 73, and is band-limited by the video intermediate frequency filter 73. The band-limited signal is supplied to a video detector 74 and a carrier wave recovery circuit 75. The carrier wave regeneration circuit 75 regenerates the carrier wave II for synchronous detection. The band-limited signal is transmitted to the video detector 74 using the carrier wave 1.
The signal is detected in the video baseband signal and becomes a video baseband signal. The video baseband signal is separated into a luminance signal and a carrier color signal by a luminance/color signal separation circuit 74, and the separated general color signal is outputted to an output terminal 82. Further, the output of the tuner 72 is band-limited by a filter 77. Carrier wave regeneration circuit 75
The output signal of the filter 77 is synchronously detected in the multiple signal detector 79 using the carrier wave I2 obtained by shifting the phase of the carrier wave I obtained from the carrier wave I by 90° in the same direction as the direction in which the phase was shifted by the phase shifter 78 on the transmitter side. . The detected signal is converted to the original frequency by a frequency converter 80, and the low frequency component of the luminance signal is separated by a luminance/chrominance signal separation circuit 76.
The signals are added by an adder 81 to form a broadband luminance signal, which is output to an output terminal 83.

発明が解決しようとする問題点 以上のように、多重信号で搬送波を直交変調し帯域制限
したものを変調された主映像信号に重畳した場合、映像
検波方式によっては、またゴーストなど伝送歪が生じて
いるときには、主映像信号に対する多重信号のクロスト
ークが発生し妨害となりやすい。またゴーストなど伝送
歪が生じているときには、多重信号に対する主映像信号
のクロストークも発生し、多重信号の良好な再生ができ
にくい場合がある。Problems to be Solved by the Invention As mentioned above, when a carrier wave is orthogonally modulated using a multiplexed signal and a band-limited signal is superimposed on a modulated main video signal, transmission distortion such as ghosting may occur depending on the video detection method. When the main video signal is being used, crosstalk between the multiplexed signal and the main video signal is likely to occur and cause interference. Furthermore, when transmission distortion such as ghosting occurs, crosstalk between the main video signal and the multiplexed signal also occurs, making it difficult to reproduce the multiplexed signal well.

本発明はかかる問題点に鑑みてなされたもので、現行の
テレビジョン方式と両立性があり、特に現行のテレビジ
ョン受像機にあたえる妨害を少なくし、また伝送歪によ
る影響を軽減することを特徴とし、規格で定められた帯
域内で多量の情報を多重伝送できるテレビジョン信号を
復調することのできるテレビジョン復調装置を提供する
ことを目的とする。The present invention has been made in view of these problems, and is compatible with current television systems, and is particularly characterized by reducing interference to current television receivers and reducing the effects of transmission distortion. It is an object of the present invention to provide a television demodulator that can demodulate a television signal that can multiplex transmit a large amount of information within a band defined by a standard.

問題点を解決するための手段 上記問題点を解決するために本発明のテレビジョン信号
復調装置は、残留側波帯振幅変調されたテレビジョン信
号の残留側波帯域内または前記残留側波帯振幅変調の映
像搬送波の周波数に関して前記残留側波帯とは対称な帯
域内もしくは両帯域内に、一水平走査期間毎に、また一
フィールド毎に、あるいは一フレーム毎に位相反転した
副搬送波により多重元信号を周波数変換した多重信号で
、前記映像搬送波と同一周波数でかつ位相が９０°異な
る搬送波を両側波帯振幅変調し、映像搬送波周波数で半
分に減衰し、かつ前記映像搬送波周波数に関して奇対称
な振幅特性を有するナイキストフィルタにより残留側波
帯にした信号を、帰線期間で搬送波除去し前記テレビジ
ョン信号に重畳した信号を、直交ひずみを除去するフィ
ルタで帯域制限し、同期検波することにより前記多重信
号を復調し、前記副搬送波と同一周波数、同一位相の再
生副搬送波により周波数変換することによって多重元信
号を復調する手段を具備した構成となっている。Means for Solving the Problems In order to solve the above-mentioned problems, the television signal demodulator of the present invention provides a television signal demodulation device that uses the vestigial sideband amplitude within the vestigial sideband of a vestigial sideband amplitude modulated television signal or the vestigial sideband amplitude. Multiplexing is performed by subcarriers whose phase is inverted every horizontal scanning period, every field, or every frame, in a band symmetrical to the vestigial sideband or in both bands with respect to the frequency of the video carrier wave of modulation. A multiplexed signal obtained by converting the frequency of a signal, in which a carrier wave having the same frequency as the video carrier wave and having a phase different by 90 degrees is modulated in double-sided band amplitude, the amplitude is attenuated by half at the video carrier frequency, and the amplitude is oddly symmetrical with respect to the video carrier frequency. The carrier wave is removed from the signal made into a residual sideband by a Nyquist filter having characteristics, and the signal superimposed on the television signal is band-limited by a filter that removes orthogonal distortion, and synchronous detection is performed to perform the multiplexing. The configuration includes means for demodulating the signal and converting the frequency using a reproduced subcarrier having the same frequency and the same phase as the subcarrier, thereby demodulating the multiplexed signal.

作用 本発明は、上記した方法によって、現行テレビジョン放
送の規格の帯域内で別の情報を多重伝送可能とするテレ
ビジョン信号を生成することにより、専用の受信機では
従来のテレビジョン放送の映像のみならず、伝送歪によ
る影響少なく多重された情報をも得ることができる。Effect of the Invention The present invention uses the above-described method to generate a television signal that enables multiplex transmission of different information within the band of the current television broadcasting standard, so that a dedicated receiver can transmit images of conventional television broadcasting. In addition, multiplexed information can also be obtained with less influence from transmission distortion.

実施例 以下本発明の一実施例について、図面を参照しながら説
明する。EXAMPLE An example of the present invention will be described below with reference to the drawings.

以下では地上放送の場合を例にとり、輝度信号の高域成
分が多重伝送されているものとする。第１図はテレビジ
ョン信号復調装置のブロック図の一例である。３１はア
ンテナ、３２はチューナ、３３は映像中間周波フィルタ
、３４は映像検波器、３５は搬送波再生回路、３７はフ
ィルタ、３８は移相器、３９は多重信号検波器、３６は
輝度・色信号分離回路、４１は加算器、４０は周波数変
換回路、４２は搬送色信号出力端子、４３は輝度信号出
力端子、４４は副搬送波入力端子である。送信側から送
出された信号はアンテナ３１で受信され、チューナ３２
で中間周波数帯に周波数変換され、映像中間周波フィル
タ３３で帯域制限される。帯域制限された信号は、映像
検波器３４、搬送波再生回路３５に供給される。搬送波
再生回路３５では、同期検波用の搬送波■１を再生する
。帯域制限された信号は、搬送波１１で映像検波器３４
において検波される。またチューナ３２の出力はフィル
タ３７で帯域制限する。搬送波再生回路３５から得られ
る搬送波■１を移相器３８により送信側と同一方向に９
０°位相シフトさせた搬送波Ｉ２で、帯域制限された信
号を多重信号検波器３９において同期検波する。検波出
力は周波数変換回路４０において、送信時の副搬送波と
同一周波数、同一位相の副搬送波で周波数変換され、高
域輝度信号成分Ｙ、となる。映像検波器３４の出力は輝
度・色信号分離回路３６に入力され、搬送色信号Ｃと低
域輝度信号成分ＹＬに分離される。高域輝度信号成分Ｙ
、と低域輝度信号成分ＹＬは加算器４１で加算され、広
帯域の輝度信号となる。In the following, we will take the case of terrestrial broadcasting as an example, and assume that high-frequency components of luminance signals are multiplexed and transmitted. FIG. 1 is an example of a block diagram of a television signal demodulator. 31 is an antenna, 32 is a tuner, 33 is a video intermediate frequency filter, 34 is a video detector, 35 is a carrier wave regeneration circuit, 37 is a filter, 38 is a phase shifter, 39 is a multiple signal detector, 36 is a brightness/color signal 41 is an adder, 40 is a frequency conversion circuit, 42 is a carrier color signal output terminal, 43 is a luminance signal output terminal, and 44 is a subcarrier input terminal. The signal sent from the transmitting side is received by the antenna 31, and the tuner 32
The signal is frequency-converted to an intermediate frequency band by the video intermediate frequency filter 33, and band-limited by the video intermediate frequency filter 33. The band-limited signal is supplied to a video detector 34 and a carrier recovery circuit 35. The carrier wave regeneration circuit 35 regenerates the carrier wave 1 for synchronous detection. The band-limited signal is transmitted to a video detector 34 using a carrier wave 11.
The wave is detected at Further, the output of the tuner 32 is band-limited by a filter 37. The carrier wave 1 obtained from the carrier wave regeneration circuit 35 is shifted 9 in the same direction as the transmitting side by the phase shifter 38.
The band-limited signal is synchronously detected by the multiple signal detector 39 using the carrier wave I2 with a 0° phase shift. The detected output is frequency-converted in the frequency conversion circuit 40 using a subcarrier having the same frequency and phase as the subcarrier during transmission, and becomes a high-band luminance signal component Y. The output of the video detector 34 is input to a luminance/chrominance signal separation circuit 36, where it is separated into a carrier color signal C and a low-band luminance signal component YL. High-frequency luminance signal component Y
, and the low-band luminance signal component YL are added by an adder 41 to form a wideband luminance signal.

次に本発明の一実施例における送信側でのテレビジョン
信号合成装置のブロック図を第２図に示す。輝度信号の
高域成分を多重する場合を例にとって説明するが、多重
信号は輝度信号の高域成分に限るものではない。２は輝
度信号入力端子、３は周波数分離器、５は周波数変換器
、４は副搬送波、１５は位相制御器、１は搬送色信号入
力端子、６は加算器、７は振幅変調器、８は第１フイル
タ、９は発振器、１０は移相器、１１は変調器、１２は
第２フイルタ、１３は加算器、１４は合成テレビジョン
信号出力端子である。輝度信号を周波数分離器３で高域
輝度信号成分ＹＨと低域輝度信号成分ＹＬに分離する。Next, FIG. 2 shows a block diagram of a television signal combining apparatus on the transmitting side in an embodiment of the present invention. An example will be explained in which high-frequency components of a luminance signal are multiplexed, but the multiplexed signal is not limited to high-frequency components of a luminance signal. 2 is a luminance signal input terminal, 3 is a frequency separator, 5 is a frequency converter, 4 is a subcarrier, 15 is a phase controller, 1 is a carrier color signal input terminal, 6 is an adder, 7 is an amplitude modulator, 8 1 is a first filter, 9 is an oscillator, 10 is a phase shifter, 11 is a modulator, 12 is a second filter, 13 is an adder, and 14 is a composite television signal output terminal. A frequency separator 3 separates the brightness signal into a high-band brightness signal component YH and a low-band brightness signal component YL.

低域輝度信号成分ＹＬは加算器６で搬送色信号と加算さ
れる。高域輝度信号成分Ｙ□は周波数変換器５で副搬送
波により周波数変換される。第３図（ａｌ　（ｂｌに示
すように、例えば輝度信号の高域成分４．２〜５．２Ｍ
Ｈｚを４．２Ｍｆｌｚの副搬送波で０〜１　、　ＱＭＨ
ｚに周波数変換するものとする。このとき副搬送波は位
相制御器１５により、一水平走査期間毎に、または一フ
ィールド毎に、または一フレーム毎に位相が反転するよ
うに制御される。このような位相の副搬送波により周波
数変換された信号は変調器１１に人力される。加算器６
の出力信号で、発振器９から得られる搬送波Ｐ１を振幅
変調器７により振幅変調する。得られた振幅変調波を第
１フイルタ８で帯域制限し残留側波帯にした後に加算器
１３に加える。発振器９から得られる搬送波Ｐ＋を移相
器１０により９０°位相シフトさせたものを搬送波Ｐ２
とする。変調器１１において、周波数変換器５の出力信
号で、搬送波Ｐ２を両側波帯振幅変調し帰線期間では搬
送波除去両側波帯振幅変調する。なお、移相器１０の位
相シフト方向は固定でもよいが、例えば一水平走査期間
毎に位相シフト方向を変えてやってもよい。変調された
信号を第２フィルタ１２で帯域制限した後に加算器１３
に加える。The low-band luminance signal component YL is added to the carrier color signal by an adder 6. The high-frequency luminance signal component Y□ is frequency-converted by a frequency converter 5 using a subcarrier. As shown in Figure 3 (al (bl), for example, the high frequency component of the luminance signal is 4.2 to 5.2M
Hz with 4.2Mflz subcarrier from 0 to 1, QMH
Assume that the frequency is converted to z. At this time, the phase of the subcarrier is controlled by the phase controller 15 so that the phase thereof is inverted every horizontal scanning period, every field, or every frame. The signal frequency-converted by the subcarrier having such a phase is input to the modulator 11 . Adder 6
The amplitude modulator 7 modulates the amplitude of the carrier wave P1 obtained from the oscillator 9 using the output signal. The obtained amplitude modulated wave is band-limited by the first filter 8 to form a residual sideband, and then added to the adder 13. The carrier wave P+ obtained from the oscillator 9 is phase-shifted by 90° by the phase shifter 10, and the carrier wave P2 is obtained by shifting the phase of the carrier wave P+ by 90° by the phase shifter 10.
shall be. In the modulator 11, the carrier wave P2 is amplitude-modulated in both sidebands using the output signal of the frequency converter 5, and during the retrace period, the carrier wave is removed and amplitude-modulated in both sidebands. Note that the phase shift direction of the phase shifter 10 may be fixed, but it may also be changed, for example, every horizontal scanning period. After band-limiting the modulated signal with the second filter 12, the adder 13
Add to.

加算器１３の出力が合成テレビジョン信号となる。The output of adder 13 becomes a composite television signal.

すなわち映像ベースバンド信号に多重信号が重畳されて
合成テレビジョン信号となる。なお、ここでは第１フイ
ルタの出力信号と第２フイルタの出力信号を加算したが
、第２フイルタの出力信号を振幅変調器７の出力信号と
加算したのちに第１フイルタ８に入力し、第１フイルタ
８の出力信号を合成テレビジョン信号としてもよい。That is, the multiplexed signal is superimposed on the video baseband signal to form a composite television signal. Although the output signal of the first filter and the output signal of the second filter are added here, the output signal of the second filter is added to the output signal of the amplitude modulator 7 and then inputted to the first filter 8. The output signal of one filter 8 may be a composite television signal.

以上述べたように、多重元信号を周波数変換する副搬送
波の位相を一水平走査期間毎に、または−フィールド毎
に、または一フレーム毎に反転させることにより、主映
像信号に対する多重信号のクロストークが生じた場合で
もクロストーク成分の位相が、一水平走査期間毎に、ま
たは一フィールド毎に、または一フレーム毎に反転する
ことになるので視覚的には目立たなくなる。すなわち現
行のテレビジョン受像機に与える妨害は少なくなる。つ
まり、ＮＴＳＣ方式において色信号多重時の妨害を目の
蓄積効果により軽減できるように、色副搬送波の位相を
一水平走査期間毎に、そして−フレーム毎に反転するよ
うに選んでいるのと同様のことがいえるのである。As mentioned above, by inverting the phase of the subcarrier that frequency-converts the multiplexed signal every horizontal scanning period, every field, or every frame, crosstalk of the multiplexed signal with respect to the main video signal can be avoided. Even if this occurs, the phase of the crosstalk component is inverted every horizontal scanning period, every field, or every frame, so it is not visually noticeable. That is, less interference is caused to current television receivers. In other words, in the same way as in the NTSC system, the phase of the color subcarrier is selected to be inverted every horizontal scanning period and every frame, so that interference during multiplexing of color signals can be reduced by the accumulation effect of the eye. The following can be said.

また多重信号復調時に、ゴースト等の伝送歪があイ１．
ば、多重信号に対する主映像信号のクロストークが発生
することがある。しかし、前記したように多重元信号を
周波数変換する副搬送波の位相を一水平走査期間毎に、
または一フィールド毎に、または一フレーム毎に反転さ
せ、多重信号復調時にはこの副搬送波と同位相の副搬送
波で周波数変換すれば、多重元信号は正規の位相で再生
できる。Also, when demodulating multiplexed signals, transmission distortion such as ghosts may occur.1.
For example, crosstalk between the main video signal and the multiplexed signal may occur. However, as mentioned above, the phase of the subcarrier that frequency-converts the multiplexed signal is changed every horizontal scanning period.
Alternatively, if the subcarrier is inverted every field or every frame and the frequency is converted using a subcarrier having the same phase as this subcarrier during demodulation of the multiplexed signal, the multiplexed signal can be reproduced with a normal phase.

そして伝送歪による多重信号に対する主映像信号のクロ
ストークは反転位相になるので、クロストークが生じた
としても視覚的には目立たなくなる。Since crosstalk between the main video signal and the multiplexed signal due to transmission distortion has an inverted phase, even if crosstalk occurs, it is not visually noticeable.

すなわち、多重信号復調時にも伝送歪の影響を軽減する
ことができる。That is, the influence of transmission distortion can be reduced even during multiplex signal demodulation.

また多重元信号を周波数変換する副搬送波の位相を一水
平走査期間毎にかつ一フレーム毎に反転するようにし、
かつ２６３水平走査期間後に同相となるように位相制御
すれば、−フィールド後で色副搬送波の位相が同相のと
きに多重元信号を周波数変換する副搬送波の位相は逆相
になり、色に与える妨害は目の蓄積効果等によってさら
にすくなくなる。In addition, the phase of the subcarrier that frequency-converts the multiplexed signal is inverted every horizontal scanning period and every frame,
And if the phase is controlled so that they are in phase after 263 horizontal scanning periods, then when the color subcarriers are in phase after -field, the phase of the subcarrier that frequency-converts the multiplexed signal will be in reverse phase, which is applied to the color. The interference is further reduced by the accumulation effect of the eyes.

発明の効果 以上の説明から明らかなように、主映像信号と多重信号
とのクロストークの影響を視覚的に軽減することができ
るので、伝送歪等があっても主映像信号と同様多重信号
も良好に復調することができる。Effects of the Invention As is clear from the above explanation, the influence of crosstalk between the main video signal and the multiplexed signal can be visually reduced, so even if there is transmission distortion, the multiplexed signal will be treated as well as the main video signal. Good demodulation is possible.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例における受信側でのテレビジ
ョン信号復調装置を示すブロック図、第２図は本発明の
一実施例における送信側でのテレビジョン信号合成装置
を示すブロック図、第３図は輝度信号高域成分の周波数
変換図、第４図は従来例における送信側でのテレビジョ
ン信号合成装置を示すブロック図、第５図は従来例にお
ける受信側でのテレビジョン信号復調装置を示すブロッ
ク図である。 １０、３８・・・・・・移相器、１２・・・・・・第２
フイルタ、１５・・・・・・位相制御器、３３・・・・
・・映像中間周波フィルタ、３７・・・・・・フィルタ
、４０・・・・・・周波数変換回路。FIG. 1 is a block diagram showing a television signal demodulation device on the receiving side according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a television signal combining device on the transmitting side according to an embodiment of the present invention. Fig. 3 is a frequency conversion diagram of the high-frequency component of a luminance signal, Fig. 4 is a block diagram showing a television signal synthesis device on the transmitting side in the conventional example, and Fig. 5 is a television signal demodulation on the receiving side in the conventional example. FIG. 2 is a block diagram showing the device. 10, 38... Phase shifter, 12... Second
Filter, 15... Phase controller, 33...
...Video intermediate frequency filter, 37...Filter, 40...Frequency conversion circuit.

Claims (2)

【特許請求の範囲】[Claims] （１）残留側波帯振幅変調されたテレビジョン信号の残
留側波帯域内または前記残留側波帯振幅変調の映像搬送
波の周波数に関して前記残留側波帯とは対称な帯域内も
しくは両帯域内に、一水平走査期間毎に、また一フィー
ルド毎に、あるいは一フレーム毎に位相反転した副搬送
波により多重元信号を周波数変換した多重信号で、前記
映像搬送波と同一周波数でかつ位相が９０°異なる搬送
波を両側波帯振幅変調し、映像搬送波周波数で半分に減
衰し、かつ前記映像搬送波周波数に関して奇対称な振幅
特性を有するナイキストフィルタにより残留側波帯にし
た信号を、帰線期間で搬送波除去し前記テレビジョン信
号に重畳した信号を、直交ひずみを除去するフィルタで
帯域制限し、同期検波することにより前記多重信号を復
調し、前記副搬送波と同一周波数、同一位相の再生副搬
送波により周波数変換することによって多重元信号を復
調することを特徴とするテレビジョン信号復調装置。(1) Within the vestigial sideband of a vestigial sideband amplitude modulated television signal, or within a band symmetrical to the vestigial sideband with respect to the frequency of the video carrier wave of the vestigial sideband amplitude modulation, or within both bands. , a multiplexed signal obtained by converting the frequency of a multiplexed signal using a subcarrier whose phase is inverted every horizontal scanning period, every field, or every frame, and a carrier wave having the same frequency as the video carrier wave and having a phase different by 90 degrees. The signal is amplitude modulated in both sidebands, attenuated by half at the video carrier frequency, and made into a vestigial sideband by a Nyquist filter having amplitude characteristics oddly symmetrical with respect to the video carrier frequency, and the carrier is removed during the retrace period. Band-limiting the signal superimposed on the television signal with a filter that removes orthogonal distortion, demodulating the multiplexed signal by performing synchronous detection, and converting the frequency using a regenerated subcarrier having the same frequency and phase as the subcarrier. 1. A television signal demodulation device characterized in that it demodulates a multiplexed signal. （２）副搬送波は一水平走査期間毎にかつ一フレーム毎
に位相反転し、かつ２６３水平走査期間後に同相となる
ように位相制御された信号であることを特徴とする特許
請求の範囲第（１）項記載のテレビジョン信号復調装置
。(2) The subcarrier is a signal whose phase is inverted every horizontal scanning period and every frame, and whose phase is controlled so that it becomes the same phase after 263 horizontal scanning periods ( 1) The television signal demodulator according to item 1).