JPH02288489A - Pal/secam signal discriminator and pal/secam signal recording and reproducing device - Google Patents
Pal/secam signal discriminator and pal/secam signal recording and reproducing deviceInfo
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- JPH02288489A JPH02288489A JP1108846A JP10884689A JPH02288489A JP H02288489 A JPH02288489 A JP H02288489A JP 1108846 A JP1108846 A JP 1108846A JP 10884689 A JP10884689 A JP 10884689A JP H02288489 A JPH02288489 A JP H02288489A
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Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、ビデオテープレコーダ（以下ＶＴＲと呼ぶ）
等に用いられるＰＡＬ信号やＳＥＣＡＭ信号などの色信
号を処理する装置に関するものである。[Detailed Description of the Invention] Industrial Application Field The present invention is directed to a video tape recorder (hereinafter referred to as VTR).
The present invention relates to a device for processing color signals such as PAL signals and SECAM signals used in the following applications.
従来の技術
映像信号の伝送方式としてＰＡＬ方式やＳ Ｅ ＣＡ
Ｍ方式が用いられる。これらの両方の方式をＶＴＲに記
録する場合、回路規模を小さくするために回路を兼用で
きる記録再生方式が望ましい。従来これらの信号を記録
再生する際、ＶＨ３−ＶＴＲなどの民生用ＶＴＲでは搬
送色信号を低域に周波数変換して記録し、再生時には反
対に周波数を元に戻す方法がよく■いられている。また
そのような場合どの方式で記録されているか、或は記録
しようとする信号がどの方式かを判別する必要が生じる
。以下、第３図を参照しながら従来のＰＡＬ／ＳＥＣＡ
Ｍ信号判別装置およびＰＡＬ／ＳＥＣＡＭ信号記録再生
装置について説明する。Conventional technology The PAL system and S E CA are used as video signal transmission systems.
M method is used. When recording on a VTR using both of these methods, it is desirable to use a recording/reproducing method that allows the circuit to be used in common in order to reduce the circuit scale. Conventionally, when recording and reproducing these signals, in consumer VTRs such as VH3-VTRs, the frequency of the carrier color signal is converted to a lower frequency band, and then the frequency is converted back to the original frequency during playback. . In such a case, it becomes necessary to determine which method is being used to record or which method is used for the signal to be recorded. Below, with reference to Figure 3, the conventional PAL/SECA
The M signal discrimination device and the PAL/SECAM signal recording and reproducing device will be explained.
第３図は従来例の構成を示したブロック図である。記録
時には入力された搬送色信号は乗算器１０でキャリア発
生回路９から発生されるキャリアと乗算され低域に周波
数変換される。逆に、再生時には低域変換された搬送色
信号が元の周波数に周波数変換されて戻される。入力の
搬送色信号がＰＡＬ信号の場合は直角二相変調された信
号であり、ＳＥＣＡＭ信号の場合はＦ’Ｍ変調信号であ
る。FIG. 3 is a block diagram showing the configuration of a conventional example. During recording, the input carrier color signal is multiplied by a carrier generated from a carrier generation circuit 9 in a multiplier 10 and frequency-converted to a lower frequency band. Conversely, during reproduction, the carrier color signal that has been low-frequency converted is frequency-converted back to its original frequency. When the input carrier color signal is a PAL signal, it is a quadrature two-phase modulated signal, and when it is a SECAM signal, it is an F'M modulated signal.
ＳＥＣＡＭ方式の搬送色信号を低域に周波数変換して記
録する方法は、周波数変換回路をＰＡＬ方式の回路と兼
用できるので民生用ＶＴＲ等でよく用いられている。一
方、入力された搬送色信号がＰＡＬ方式かＳＥＣＡＭ方
式かを判別するためにＰＡＬ／ＳＥＣＡＭ信号判別回路
１が用いられる。The method of converting the frequency of a SECAM system carrier color signal to a low frequency band and recording the signal is often used in consumer VTRs and the like because the frequency conversion circuit can be used as a PAL system circuit. On the other hand, a PAL/SECAM signal discrimination circuit 1 is used to determine whether the input carrier color signal is of the PAL system or the SECAM system.
ＰＡＬ／ＳＥＣＡＭ信号判別回路１に於て、入力された
搬送色信号はＦＭ復調器２でＦＭ復調されデイエンファ
シス回路４でデイエンファシスされる。デイエンファシ
ス回路４の出力はサンプル・ホールド回路６と７に送ら
れる。サンプル・ホールド回路６と７はタイミング発生
回路５がら発生するタイミング信号によりそれぞれ２水
平同期期間おきにデイエンファシス回路４の出力のバー
スト期間の信号レベルをホールドする。例えばサンプル
・ホールド回路６は偶数番目のラインのバースト信号を
、サンプル・ホールド回路７は奇数番目のラインのバー
スト信号のレベルをホールドする。In the PAL/SECAM signal discrimination circuit 1, the input carrier color signal is FM demodulated by an FM demodulator 2 and de-emphasized by a de-emphasis circuit 4. The output of de-emphasis circuit 4 is sent to sample and hold circuits 6 and 7. The sample and hold circuits 6 and 7 each hold the signal level of the output of the de-emphasis circuit 4 during the burst period every two horizontal synchronization periods using a timing signal generated by the timing generation circuit 5. For example, the sample and hold circuit 6 holds the level of the burst signal on the even numbered line, and the sample and hold circuit 7 holds the level of the burst signal on the odd numbered line.
レベル比較器８はサンプル・ホールド回路６と７から得
られた偶数番目と奇数番目のラインのバーストレベルを
比較する。また、キャリア発生回路３はＦＭ復調に必要
なキャリアを発生する。A level comparator 8 compares the burst levels of the even and odd lines obtained from the sample and hold circuits 6 and 7. Further, the carrier generation circuit 3 generates carriers necessary for FM demodulation.
つぎに、第４図を用いて動作をさらに詳しく説明する。Next, the operation will be explained in more detail using FIG.
第４図はＰＡＬ方式とＳＥＣＡＭ方式の色副搬送波の周
波数スペクトルを示している。横軸が周波数であり単位
はＭＨｚ、縦軸は各成分のレベルである。ＰＡＬ方式の
キャリアは４．４３３Ｇ１８７５ＭＨｚである。ＳＥＣ
ＡＭ方式では１水平同期期間（以下ＩＨと呼ぶ）毎にＢ
−Ｙ信号とＲ−Ｙ信号が交互に伝送され、それらの搬送
波周波数はそれぞれ４．２５ＭＨｚ、４．４０６２５Ｍ
Ｈｚである。つまりＳＥＣＡＭ方式の色副搬送波周波数
はＩＨ毎に入れ替わる。ところで、ＦＭ復調器２は入力
周波数に比例したレベルの出力を得る回路であるから、
一定周波数のキャリアを用いてＳＥＣＡＭ信号をＦＭ復
調すると復調出力のレベルがＩＨ毎に変化することにな
るので、キャリア発生回路３はＩＨ毎にＢ−Ｙ信号とＲ
−Ｙ信号の周波数のキャリアを発生してＦＭ復調器の出
力レベルを一定にする。従って、入力される搬送色信号
がＰＡＬ方式の色信号の場合には色副搬送波周波数は一
定であるから、逆にＦＭ復調器２の出力レベルがＩＨ毎
に変動する。その結果、ＰＡＬ信号の場合はサンプル・
ホールド回路６と７の出力は異なり、ＳＥＣＡＭ信号の
場合は等しくなる。従って、レベル比較器８でサンプル
・ホールド回路６と７の出力を比較すればＰＡＬ方式か
ＳＥＣＡＭ方式かを判別することができる。このような
ＦＭ復調器を利用したＰＡＬ／ＳＥＣＡＭ信号判別装置
は例えば米国特許４２４０１０２号公報、（Ｉｄｅｎｔ
ｉｆｉｃａｔｉｏｎ ５ｙｓｔｅＩＩｌｆｏｒ ＳＥＣ
ＡＭ ｏｒ ＳＥＣＡＭ／ＰＡＬ ｃｏｌｏｒ ｔｅｌ
ｅｖｌｓｌｏｎ ｒｅ−ｃｅｌｖｅｒｓ）に述べられて
いる。FIG. 4 shows frequency spectra of color subcarriers in the PAL system and the SECAM system. The horizontal axis represents frequency in MHz, and the vertical axis represents the level of each component. The carrier of the PAL system is 4.433G1875MHz. SEC
In the AM system, B is transmitted every horizontal synchronization period (hereinafter referred to as IH).
-Y signal and R-Y signal are transmitted alternately, and their carrier frequencies are 4.25MHz and 4.40625M, respectively.
It is Hz. In other words, the color subcarrier frequency of the SECAM system is changed every IH. By the way, since the FM demodulator 2 is a circuit that obtains an output with a level proportional to the input frequency,
When the SECAM signal is FM demodulated using a carrier of a constant frequency, the level of the demodulated output changes for each IH, so the carrier generation circuit 3 converts the BY signal and the R
- Generate a carrier at the frequency of the Y signal to keep the output level of the FM demodulator constant. Therefore, when the input carrier color signal is a PAL color signal, the color subcarrier frequency is constant, and conversely, the output level of the FM demodulator 2 varies for each IH. As a result, in the case of PAL signals, the sample
The outputs of hold circuits 6 and 7 are different and equal in the case of SECAM signals. Therefore, by comparing the outputs of the sample and hold circuits 6 and 7 with the level comparator 8, it is possible to determine whether the system is a PAL system or a SECAM system. A PAL/SECAM signal discrimination device using such an FM demodulator is disclosed in, for example, U.S. Pat. No. 4,240,102, (Ident
5ysteIIlfor SEC
AM or SECAM/PAL color tel
evlslon re-celvers).
発明が解決しようとする課題
しかしながら上記の構成では、ＳＥＣＡＭ方式の搬送色
信号を復調せず周波数変換して処理するＶＴＲのような
装置では、周波数変換回路以外にＰＡＬとＳＥＣＡＭ信
号を判別するためにＦＭ復調装置をよけいに具備する必
要があり、回路規模が大きくなる課題があった。Problems to be Solved by the Invention However, with the above configuration, in a device such as a VTR that processes a SECAM carrier color signal by frequency converting it without demodulating it, in addition to the frequency conversion circuit, there is a need to distinguish between PAL and SECAM signals. It is necessary to provide an extra FM demodulator, which poses a problem of increasing the circuit scale.
本発明は上記課題に鑑み、ＳＥＣＡＭ方式の搬送色信号
を復調するＦＭ復調器を用いずにＰＡＬ方式とＳＥＣＡ
Ｍ方式を判別するＰＡＬ／ＳＥＣＡＭ信号判別装置を提
供することを目的とする。In view of the above-mentioned problems, the present invention has been developed to combine the PAL system and SECA system without using an FM demodulator for demodulating the carrier color signal of the SECAM system.
An object of the present invention is to provide a PAL/SECAM signal discriminating device that discriminates M format.
課題を解決するための手段
上記問題点を解決するため本発明のＰＡＬ／ＳＥＣＡＭ
信号判別装置は、記録時には搬送色信号であり、再生時
には低域変換された搬送色信号である入力信号を互いに
位相が直交する２つの色耀号に一定周波数だけ周波数変
換し、ＰＡＬ方式の場合は前記２つの色信号は色差信号
となるような周波数変換回路と、前記周波数変換回路か
ら出力された前記２つの色信号のバースト信号のレベル
を検出するレベル検出回路と、前記レベル検出口路の出
力と前記レベル検出回路の１水平同期期間前の出力との
差を算出する演算回路と、前記演算回路の出力と基準レ
ベルとを比較しその出力をＰＡＬ／ＳＥＣＡＭ判別信号
とするように構成されるものである。Means for Solving the Problems In order to solve the above problems, the PAL/SECAM of the present invention
The signal discrimination device frequency-converts the input signal, which is a carrier color signal during recording and a carrier color signal after low frequency conversion during playback, by a certain frequency into two color signals whose phases are orthogonal to each other. a frequency conversion circuit for converting the two color signals into color difference signals; a level detection circuit for detecting the level of a burst signal of the two color signals output from the frequency conversion circuit; an arithmetic circuit that calculates the difference between the output and the output of the level detection circuit one horizontal synchronization period before, and a computation circuit that compares the output of the arithmetic circuit with a reference level and uses the output as a PAL/SECAM discrimination signal. It is something that
作用
本発明は上記の構成により、ＦＭ復調器を用いずＰＡＬ
とＳＥＣＡＭ信号を判別することができる。Operation The present invention has the above-described configuration, and can perform PAL without using an FM demodulator.
and SECAM signals.
また本発明はＰＡＬの復調された色差信号を出力するこ
ともできる。Further, the present invention can also output a PAL demodulated color difference signal.
実施例
以下、本発明のＰＡＬ／ＳＥＣＡＭ信号判別装置及びＰ
ＡＬ／ＳＥＣＡＭ信号記録再生装置について第１図を用
いて説明する。Examples Below, the PAL/SECAM signal discriminator and PAL/SECAM signal discriminator of the present invention will be described.
The AL/SECAM signal recording and reproducing device will be explained using FIG.
第１図は本発明の第１の実施例の構成を示したブロック
図である。FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention.
第１図に於て、入力端子４４に入力される信号は、記録
時は搬送色信号であり再生時には低域変換された搬送色
信号である。この入力信号は乗算器２３，２４、キャリ
ア発生回路２５、ローパスフルタ２６．２７から構成さ
れる周波数変換回路２０に入力される。キャリア発生回
路２５はＰＡＬ方式の互いに位相の９０度異なる２つの
キャリアを発生する。従って、記録時には４．４３３１
１ｉ１８７５ＭＨＺであり、再生時には例えばＶＨ８−
ＶＴＲの場合６２７ＫＨｚである。このキャリアは入力
信号と乗算器２３．２４で乗算されローパスフィルタ２
６゜２７で濾波される。従って、ローパスフィルタ２６
と２７の出力には直交した２つの色差信号が得られる。In FIG. 1, the signal input to the input terminal 44 is a carrier color signal during recording, and is a carrier color signal subjected to low frequency conversion during reproduction. This input signal is input to a frequency conversion circuit 20 comprising multipliers 23 and 24, a carrier generation circuit 25, and low-pass filters 26 and 27. The carrier generation circuit 25 generates two carriers of the PAL system having phases different from each other by 90 degrees. Therefore, when recording, 4.4331
1i1875MHZ, for example, VH8-
In the case of a VTR, it is 627 KHz. This carrier is multiplied by the input signal in multipliers 23 and 24 and is filtered through a low-pass filter 2.
Filtered at 6°27. Therefore, the low pass filter 26
Two orthogonal color difference signals are obtained from the outputs of and 27.
つまり周波数変換回路２０はこの場合ＰＡＬの搬送色信
号の復調回路として動作する。これらの色差信号は乗算
器２８と２９、キャリア発生回路３０、加算器２２から
構成される変調回路２１に入力される。キャリア発生回
路３０は記録時には例えばｖＨ８＠ｖＴＲの場合８２７
ＫＨｚの−ｔ−ヤリアを、再生時には４．４３３Ｇ１８
７５ＭＨＺの互いに９０度位相の異なる２つのキャリア
を発生する。In other words, the frequency conversion circuit 20 in this case operates as a demodulation circuit for the PAL carrier color signal. These color difference signals are input to a modulation circuit 21 comprising multipliers 28 and 29, a carrier generation circuit 30, and an adder 22. For example, in the case of vH8@vTR, the carrier generation circuit 30 generates 827 during recording.
-t-yaria of KHz, 4.433G18 when playing
Two 75 MHZ carriers having a phase difference of 90 degrees are generated.
これらのキャリアは乗算器２８と２９で周波数変換回路
２０で復調された色差信号と乗算され、その出力が加算
器２２で加算される。その結果出力端子４５には直角二
相変調された搬送色信号が得られる。These carriers are multiplied by the color difference signal demodulated by the frequency conversion circuit 20 in multipliers 28 and 29, and the outputs thereof are added together in an adder 22. As a result, a carrier color signal subjected to quadrature two-phase modulation is obtained at the output terminal 45.
以上の動作に於て、周波数変換回路２０と変調回路２１
の従属接続は、例えば記録時に入力端子４４から入力さ
れた４、４３３８１８７５Ｍ ＨＺの搬送色信号が出力
端子４５に８２７ＫＨｚの搬送色信号となって出力され
るので、従来例の周波数変換の動作に相当する。再生の
場合もその逆の周波数変換が行なわれる。しかも周波数
変換された信号と同時に、復調された色差信号も得るこ
とができる。In the above operation, the frequency conversion circuit 20 and the modulation circuit 21
For example, the subordinate connection of 4,43381875 MHz carrier color signal inputted from the input terminal 44 during recording is output as an 827 kHz carrier color signal to the output terminal 45, so this corresponds to the frequency conversion operation of the conventional example. do. In the case of reproduction, the reverse frequency conversion is also performed. Moreover, a demodulated color difference signal can be obtained simultaneously with the frequency-converted signal.
入力端子４４からの入力信号がＳＥＣＡＭ方式の信号の
場合、今述べたように周波数変換回路２０と変調回路２
１は周波数変換の動作を行なうので、従来例と同様に出
力端子４５には、記録時は低域変換された搬送色信号が
再生時は記録時の元の周波数の搬送色信号が得られる。If the input signal from the input terminal 44 is a SECAM signal, the frequency conversion circuit 20 and the modulation circuit 2 are used as described above.
1 performs a frequency conversion operation, so that, as in the conventional example, at the output terminal 45, a low frequency converted carrier color signal is obtained during recording, and a carrier color signal having the original frequency at the time of recording is obtained during reproduction.
この場合周波数変換回路２０から出力される２つの色信
号の周波数は、入力端子４４から入力した搬送色信号の
周波数からキャリア発生回路２５の出力の周波数を弓い
た値になる。このことを第２図を用いて説明する。In this case, the frequencies of the two color signals output from the frequency conversion circuit 20 are a value obtained by subtracting the frequency of the carrier color signal input from the input terminal 44 and the frequency of the output of the carrier generation circuit 25. This will be explained using FIG. 2.
第２図は周波数変換回路２０の出力信号のスペクトルを
現わしており、横軸は周波数で単位はＭ Ｈｚ １
縦軸は各スペクトルのレベルを示している。ａは入力が
ＰＡＬ方式、ｂとＣはＳＥＣＡＭ方式の搬送色信号の場
合であり、ｂはＲ−Ｙ信号、ＣはＢ−Ｙ信号である。先
にもべたように、周波数変換回路２０の出力には入力周
波数からキャリア発生回路２５のキャリア周波数だけ周
波数が低域に変換され、しかもキャリア周波数はＰＡＬ
の色副搬送波周波数であるので、入力がＰＡＬ信号の場
合には第２図ａに示すようにＤＣに周波数変換される。FIG. 2 shows the spectrum of the output signal of the frequency conversion circuit 20, where the horizontal axis is the frequency and the unit is MHz 1.
The vertical axis indicates the level of each spectrum. A is a case where the input is a PAL system carrier color signal, b and C are a SECAM system carrier color signal, b is an RY signal, and C is a BY signal. As mentioned earlier, the frequency of the output of the frequency conversion circuit 20 is converted from the input frequency to a lower frequency by the carrier frequency of the carrier generation circuit 25, and the carrier frequency is PAL.
Since the color subcarrier frequency is , if the input is a PAL signal, the frequency is converted to DC as shown in FIG. 2a.
すなわち色差信号に復調される。ＳＥＣＡＭ信号の場合
記録時には、Ｂ−Ｙ信号のときは入力の搬送色信号周波
数がさきに述べたように４．２５ＭＨＺＮ Ｒ−Ｙ信
号のときは４．４０８２５ＭＨｚであるから、ＰＡＬの
色副搬送波周波数４．４３３１１ｉ１８７５ＭＨｚとの
差をとるとそれぞれｂとＣに示すように０．０２７３ｆ
ｉ８７５Ｍ ＨＺ、 ０．１８３６１８７５Ｍ ＨＺ
になる。That is, it is demodulated into a color difference signal. In the case of a SECAM signal, when recording, the input carrier color signal frequency is 4.25MHz for the B-Y signal, and 4.40825MHz for the R-Y signal, so the PAL color subcarrier frequency Taking the difference from 4.43311i1875MHz is 0.0273f as shown in b and c, respectively.
i875M HZ, 0.18361875M HZ
become.
また、再生時には周波数変換回路２０の入力は低域変換
された搬送色信号であるが、記録時に低域変換されると
き、ＰＡＬ方式の場合もＳＥＣＡＭ方式の場合も同じ周
波数だけ周波数変換されているので両方式の搬送波周波
数の相対関係は変わらない。従って、再生時も周波数の
関係は第２図と同じになる。Furthermore, during playback, the input to the frequency conversion circuit 20 is a carrier color signal that has been low-frequency converted, but when low-frequency conversion is performed during recording, the frequency is converted by the same frequency in both the PAL system and the SECAM system. Therefore, the relative relationship between the carrier frequencies of both methods remains unchanged. Therefore, during reproduction, the frequency relationship is the same as in FIG. 2.
このような周波数を有する２つの色信号はレベル検出回
路３５に入力される。レベル検出回路３５において、バ
ーストゲート回路４２．４３でバースト期間の信号を抜
き出し、２東回路３１．３２でそれぞれのレベルを２乗
し、それらの出力は加算器３３で加算されて、平方根回
路３４でその平方根が算出される。つまりレベル検出回
路３５は入力される２つの信号の２乗の和の平方根を算
出する。従って、この場合のように、入力される２つの
信号が位相の直交する信号の場合は信号の振幅が算出さ
れることになる。このようにして得られたレベルは演算
回路４７に送られる。演算回路４７に於て、入力信号は
遅延回路３７でＩＨ遅延され、ＩＨ遅延していない信号
との差が減算回路３６で算出され、絶対値回路３８でそ
の絶対値が算出される。この出力はローパスフィルタ３
９を通って比較回路４０で基準レベルと比較され、その
出力はＰＡＬ／ＳＥＣＡＭ信号判別信号として出力端子
４６へ出力される。Two color signals having such frequencies are input to the level detection circuit 35. In the level detection circuit 35, the burst gate circuits 42 and 43 extract the signals during the burst period, the two east circuits 31 and 32 square the respective levels, the outputs are added together in the adder 33, and the square root circuit 34 The square root of it is calculated. In other words, the level detection circuit 35 calculates the square root of the sum of the squares of the two input signals. Therefore, when the two input signals have orthogonal phases as in this case, the amplitude of the signal is calculated. The level thus obtained is sent to the arithmetic circuit 47. In the arithmetic circuit 47, the input signal is delayed by IH in the delay circuit 37, the difference with the signal not delayed by IH is calculated in the subtraction circuit 36, and its absolute value is calculated in the absolute value circuit 38. This output is low pass filter 3
9 and is compared with a reference level in a comparator circuit 40, and its output is outputted to an output terminal 46 as a PAL/SECAM signal discrimination signal.
ところで、周波数変換回路２ｏの出力の２つの色信号は
ローパスフィルタ２６．２７で帯域制限されている。そ
の周波数特性の例を第２図に示している。図から判るよ
うにローパスフィルタ２６゜２７で帯域制限されると第
２図ａ＋ ｂＨＣのレベルには差が生じる。前に述べ
たように、ＰＡＬ方式の場合にはその搬送波周波数は一
定であるが、ＳＥＣＡＭ方式の場合にはＩＨ毎に異なる
（第２図すとＣ）。従って、レベル検出器３５の出力は
ＩＨ毎に異なるレベルが出方されるので、減算回路の出
力はＰＡＬ方式の場合は零であるが、ＳＥＣＡＭ方式の
場合は第２図すとＣのレベル差に相゛当する値が生じる
。従って、この絶対値を比較回路４０で零かそうでない
かを判別すれば久方端子４４からの入力信号がＰＡＬ方
式がＳＥＣＡＭ方式かを判別することができる。Incidentally, the two color signals output from the frequency conversion circuit 2o are band-limited by the low-pass filters 26 and 27. An example of the frequency characteristics is shown in FIG. As can be seen from the figure, when the band is limited by the low-pass filters 26 and 27, a difference occurs between the levels of a+bHC in FIG. 2. As mentioned earlier, in the case of the PAL system, the carrier wave frequency is constant, but in the case of the SECAM system, it differs for each IH (C in Figure 2). Therefore, the output of the level detector 35 is a different level for each IH, so the output of the subtraction circuit is zero in the case of the PAL system, but in the case of the SECAM system, the level difference of C in Figure 2 is A value corresponding to is generated. Therefore, by determining whether this absolute value is zero or not using the comparison circuit 40, it is possible to determine whether the input signal from the long terminal 44 is the PAL system or the SECAM system.
なお、以上の説明でキャリア発生回路２５はＰＡＬの色
副搬送波を発生するとしたが、ＰＡＬ方式とＳＥＣＡＭ
方式の判別はＳＥＣＡＭの色副搬送波周波数がＩＨ毎に
異なることを利用しているので、別の一定の周波数を用
いてもＰＡＬ／ＳＥＣＡＭ信号判別装置は動作する。In the above explanation, it is assumed that the carrier generation circuit 25 generates a PAL color subcarrier.
Since the system discrimination utilizes the fact that the color subcarrier frequency of SECAM differs from IH to IH, the PAL/SECAM signal discriminator can operate even if another fixed frequency is used.
発明の効果
以上の説明から明らかなように、本発明を用いればＳＥ
ＣＡＭ方式の搬送色信号を復調するＦＭ復調器を用いず
にＰＡＬ方式とＳＥＣＡＭ方式を判ｙＪＩＶすることが
できる。Effects of the Invention As is clear from the above explanation, if the present invention is used, SE
It is possible to distinguish between the PAL system and the SECAM system without using an FM demodulator that demodulates the carrier color signal of the CAM system.
また本発明によれば、ＰＡＬ方式の搬送色信号を記録再
生するために周波数変換する一方で、復調された色差信
号を得ることができる。Further, according to the present invention, a demodulated color difference signal can be obtained while converting the frequency of a PAL carrier color signal for recording and reproduction.
第１図は本発明の実施例の構成を示したブロック図、第
２図は周波数変換回路２ｏの出方信号と、ローパスフィ
ルタ２８．２７の周波数特性を示した特性図、第３図は
従来例の構成を示したブロック図、第４図はＰＡＬとＳ
ＥＣＡＭ方式の色副搬送波周波数を示した特性図である
。
１−ＰＡＬ／ＳＥＣＡＭ判別回路、 １０−・・乗算
器、 ２０・・・周波数変換回路、路、 ３５・・
・レベル検出回路、
フィルタ、 ４７・・・演算回路。Fig. 1 is a block diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a characteristic diagram showing the output signal of the frequency conversion circuit 2o and the frequency characteristics of the low-pass filters 28 and 27, and Fig. 3 is a conventional A block diagram showing the configuration of an example, Figure 4 shows PAL and S
FIG. 3 is a characteristic diagram showing color subcarrier frequencies of the ECAM method. 1-PAL/SECAM discrimination circuit, 10-... multiplier, 20... frequency conversion circuit, circuit, 35...
・Level detection circuit, filter, 47...Arithmetic circuit.
Claims (3)
換された搬送色信号であるＰＡＬあるいはＳＥＣＡＭ方
式の入力信号を互いに位相が直交する２つの色信号に一
定周波数だけ周波数変換し、ＰＡＬ方式の場合は前記２
つの色信号は色差信号となるような周波数変換回路と、 前記周波数変換回路から出力された前記２つの色信号の
バースト信号のレベルを検出するレベル検出回路と、 前記レベル検出回路の出力と前記レベル検出回路の１水
平同期期間前の出力との差を算出する演算回路とを具備
し、 前記演算回路の出力と基準レベルとを比較しその出力を
ＰＡＬ／ＳＥＣＡＭ判別信号とするＰＡＬ／ＳＥＣＡＭ
信号判別装置。(1) A PAL or SECAM input signal, which is a carrier color signal during recording and a carrier color signal after low frequency conversion during playback, is frequency-converted by a certain frequency into two color signals whose phases are orthogonal to each other. In the case of 2 above
a frequency conversion circuit for converting one color signal into a color difference signal; a level detection circuit for detecting the level of a burst signal of the two color signals output from the frequency conversion circuit; and an output of the level detection circuit and the level. A PAL/SECAM, comprising: an arithmetic circuit that calculates a difference between the output of the detection circuit one horizontal synchronization period before, and that compares the output of the arithmetic circuit with a reference level and uses the output as a PAL/SECAM discrimination signal.
Signal discrimination device.
置に、周波数変換回路で周波数変換された２つの色信号
を直角二相変調する変調回路を具備したことを特徴とす
るＰＡＬ／ＳＥＣＡＭ信号記録再生装置。(2) PAL/SECAM signal recording, characterized in that the PAL/SECAM signal discriminating device according to claim 1 is equipped with a modulation circuit that performs orthogonal two-phase modulation of two color signals frequency-converted by a frequency conversion circuit. playback device.
れぞれ抜き出す第１と第２のバーストゲート回路と、 前記第１と第２のバーストゲート回路の出力をそれぞれ
２乗する第１と第２の２乗回路と、前記第１と第２の２
乗回路の出力を加算する加算器と、 前記加算器の出力の平方根を算出する平方根回路とを具
備して成ることを特徴とする請求項１に記載のＰＡＬ／
ＳＥＣＡＭ信号判別装置。(3) The level detection circuit includes first and second burst gate circuits that respectively extract bursts of two color signals, and first and second burst gate circuits that square the outputs of the first and second burst gate circuits, respectively. , and the first and second 2
2. The PAL/PAL system according to claim 1, further comprising: an adder that adds the outputs of the multiplication circuit; and a square root circuit that calculates the square root of the output of the adder.
SECAM signal discrimination device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1108846A JPH02288489A (en) | 1989-04-27 | 1989-04-27 | Pal/secam signal discriminator and pal/secam signal recording and reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1108846A JPH02288489A (en) | 1989-04-27 | 1989-04-27 | Pal/secam signal discriminator and pal/secam signal recording and reproducing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02288489A true JPH02288489A (en) | 1990-11-28 |
Family
ID=14495069
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1108846A Pending JPH02288489A (en) | 1989-04-27 | 1989-04-27 | Pal/secam signal discriminator and pal/secam signal recording and reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02288489A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0614320A2 (en) * | 1993-03-04 | 1994-09-07 | SANYO ELECTRIC Co., Ltd. | Television receiver and television signal determination circuit |
-
1989
- 1989-04-27 JP JP1108846A patent/JPH02288489A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0614320A2 (en) * | 1993-03-04 | 1994-09-07 | SANYO ELECTRIC Co., Ltd. | Television receiver and television signal determination circuit |
| EP0614320A3 (en) * | 1993-03-04 | 1994-11-02 | Sanyo Electric Co | Television receiver and television signal determination circuit. |
| KR100320047B1 (en) * | 1993-03-04 | 2002-03-21 | 다카노 야스아키 | TV receiver and TV signal discrimination circuit |
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