JPS592435B2 - color demodulator - Google Patents
color demodulatorInfo
- Publication number
- JPS592435B2 JPS592435B2 JP52147837A JP14783777A JPS592435B2 JP S592435 B2 JPS592435 B2 JP S592435B2 JP 52147837 A JP52147837 A JP 52147837A JP 14783777 A JP14783777 A JP 14783777A JP S592435 B2 JPS592435 B2 JP S592435B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- pal
- color
- secam
- color demodulation
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/64—Circuits for processing colour signals
- H04N9/642—Multi-standard receivers
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Processing Of Color Television Signals (AREA)
Description
【発明の詳細な説明】
本発明は、ＰＡＬ方式とＳＥＣＡＭ方式といつた２つの
カラーテレビジョン放送方式の信号のいずれをも受信し
、それぞれ適正な色復調を行なうことのできるＰＡＬ／
ＳＥＣＡＭ両用の色復調装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention provides a PAL/SECAM system that can receive signals of two color television broadcasting systems, PAL system and SECAM system, and perform appropriate color demodulation for each.
This invention relates to a color demodulation device for both SECAM and SECAM.
通常、同一国内においては同一放送方式が採用されてい
るのが一搬的であるが、国境地帯で両放送方式の電波が
受信できる地域あるいは放送方式が異なる地域を移動す
る場合などは同一の受信機でそれら異なつた放送方式に
よる信号を受像できることが必要となる。Normally, the same broadcasting system is adopted within the same country, but in areas where radio waves of both broadcasting systems can be received in border areas, or when moving between areas with different broadcasting systems, the same reception will be used. It is necessary for the device to be able to receive signals from these different broadcasting systems.
しかし、特に色信号変調方式の全く異なる方式を同一色
復調装置で復調することはできない。そこで両放送方式
の色復調装置が必要となるが、さらに、それらの両放送
方式の回路を受信信号に応じて適当に切替える必要が生
じる。本発明においては、各々で独立にＰＡＬあるいは
ＳＥＣＡＭ方式の色信号を復調できるＰＡＬ用色復調回
路とＳＥＣＡＭ用色復調回路を用い、新たに切替回路を
必要とせず、しかも切替えに必要な機能回路は、上記Ｐ
ＡＬか、あるいはＳＥＣＡＭ用色復調回路のいずれか一
方だけに含まれているだけで、受信している放送システ
ムに応じて、適当にＰＡＬもしくはＳＥＣＡＭ受信方式
に切替えられるＰＡＬ／ＳＥＣＡＭ両用色復調装置を提
供するものである。以下、本発明を図示の実施例に基い
て詳細に説明する。第１図に本発明の一実施例のプロツ
ク図を示す。However, in particular, completely different color signal modulation methods cannot be demodulated by the same color demodulation device. Therefore, color demodulation devices for both broadcasting systems are required, and it is also necessary to appropriately switch the circuits for both broadcasting systems depending on the received signal. In the present invention, a PAL color demodulation circuit and a SECAM color demodulation circuit are used, each of which can independently demodulate PAL or SECAM color signals, and no new switching circuit is required, and the functional circuits required for switching are , above P
A PAL/SECAM dual-use color demodulation device that is included in either the AL or SECAM color demodulation circuit and can be switched to PAL or SECAM reception mode appropriately depending on the receiving broadcasting system. This is what we provide. Hereinafter, the present invention will be explained in detail based on illustrated embodiments. FIG. 1 shows a block diagram of an embodiment of the present invention.
同図において、ＰＡＬ信号を受信したとき、ＰＡＬ用色
復調回路２１におけるＲ−Ｙ信号用同期検波回路１では
、Ｒ−Ｙ搬送色信号ａをＲ−Ｙ局部搬送波ｂを利用して
同期検波し、赤色差（Ｒ−Ｙ）信号ｃを得る。また、Ｂ
−Ｙ信号用同期検波回路２では、Ｂ−Ｙ搬送色信号ｄを
Ｂ−Ｙ局部搬送波ｅを利用して同期検波し、青色差（Ｂ
−Ｙ）信号ｆを得る。上記の赤色差信号ｃおよび青色差
信号ｆは各々（Ｒ−Ｙ）ＰＡＬ用スイツチ回路３および
（Ｂ−Ｙ）ＰＡＬ用スイツチ回路４を通して、それぞれ
ＰＡＬ用色復調回路２１の赤色差出力端子５および青色
差出力端子６に導かれる。一方、ＳＥＣＡＭ用色復調回
路２２では、ＳＥＣＡＭ方式の信号を受信したとき、Ｒ
−Ｙ信号用ＦＭ検波器７において、ＦＭ変調されたＲ−
Ｙ搬送色信号ｇをＦＭ検波して赤色差信号ｈを得、（Ｒ
−Ｙ）ＳＥＣＡＭスイツチ回路１０を通して、ＳＥＣＡ
Ｍ用色復調回路２２の赤色差出力端子１２に供給される
。同様にＢ−Ｙ信号用ＦＭ検波器８において、ＦＭ変調
されたＲ−Ｙ搬送色信号１をＦＭ検波して青色差信号Ｊ
を得、（Ｂ−Ｙ）ＳＥＣＡＭスイツチ回路１１を通して
青色差出力端子１３に供給される。この場合、前記Ｒ−
Ｙ信号用ＦＭ検波器７およびＢ−Ｙ信号用ＦＭ検波器８
の出力直流レベルは、システム判別信号発生器９からの
出力信号すなわち、受信している信号がＰＡＬかあるい
はＳＥＣＡＭかを示すシステム判別信号に応じて変化す
る。（Ｒ−Ｙ）および（Ｂ−Ｙ）ＳＥＣＡＭスイツチ回
路１０，１１はその入力端子の直流電圧に応じて、その
入力を色差信号出力端子１２，１３に供給したり、その
供給を停止したりする。すなわちＳＥＣＡＭ信号を受信
している時だけ、ＳＥＣＡＭスイツチ回路１０，１１は
導通するようになつている。また、ＳＥＣＡＭスイツチ
回路１０，１１の出力端子の直流レベルも受信している
システムに応じて変化し、色差出力端子５と１２，６と
１３を接続したＰＡＬ用色復調回路２１のＰＡＬ用スイ
ツチ回路３および４は、前記ＳＥＣＡＭ用スイツチ回路
１０および１１の出力端子の直流レベルによつて制御さ
れ、ＰＡＬ方式の信号を受信している時のみ、上記ＰＡ
Ｌ用スイツチ回路３，４は導通する。以上説明した構成
によつて、共通に接続された色差出力端子５と１２、お
よび６と１３には、受信しているシステムに応じて適当
な復調器で復調された色差信号が得られる。In the figure, when a PAL signal is received, the RY signal synchronous detection circuit 1 in the PAL color demodulation circuit 21 synchronously detects the RY carrier color signal a using the RY local carrier b. , obtain a red color difference (RY) signal c. Also, B
-Y signal synchronous detection circuit 2 performs synchronous detection of the B-Y carrier color signal d using the B-Y local carrier e, and detects the blue color difference (B
-Y) Obtain signal f. The above red difference signal c and blue difference signal f are passed through the (R-Y) PAL switch circuit 3 and (B-Y) PAL switch circuit 4, respectively, to the red difference output terminal 5 and the PAL color demodulation circuit 21, respectively. It is guided to the blue color difference output terminal 6. On the other hand, in the SECAM color demodulation circuit 22, when receiving the SECAM system signal, the R
- In the Y signal FM detector 7, the FM-modulated R-
The Y carrier color signal g is FM-detected to obtain the red difference signal h, and (R
-Y) SECA through the SECAM switch circuit 10
It is supplied to the red difference output terminal 12 of the M color demodulation circuit 22. Similarly, in the FM detector 8 for the B-Y signal, the FM-modulated R-Y carrier color signal 1 is FM-detected to produce the blue difference signal J.
and is supplied to the blue color difference output terminal 13 through the (B-Y) SECAM switch circuit 11. In this case, the R-
FM detector 7 for Y signal and FM detector 8 for B-Y signal
The output DC level changes according to the output signal from the system discrimination signal generator 9, that is, the system discrimination signal indicating whether the received signal is PAL or SECAM. (RY) and (B-Y) SECAM switch circuits 10 and 11 supply the input to the color difference signal output terminals 12 and 13 or stop the supply, depending on the DC voltage at the input terminal. . That is, the SECAM switch circuits 10 and 11 are rendered conductive only when receiving the SECAM signal. In addition, the DC level of the output terminals of the SECAM switch circuits 10 and 11 changes depending on the receiving system, and the PAL switch circuit of the PAL color demodulation circuit 21 which connects the color difference output terminals 5 and 12, and 6 and 13. 3 and 4 are controlled by the DC level of the output terminals of the SECAM switch circuits 10 and 11, and the PA
The L switch circuits 3 and 4 are rendered conductive. With the configuration described above, the commonly connected color difference output terminals 5 and 12 and 6 and 13 can obtain color difference signals demodulated by an appropriate demodulator depending on the receiving system.
しかも、システム判別信号発生回路９は一方の色復調回
路にのみ設置するだけで良く、上記ＰＡＬ用およびＳＥ
ＣＡＭ用色復調回路間にシステム判別信号を供給するた
めの端子を新たに設ける必要がない等の利点を有する。
第２図に本発明の具体的実施例の回路構成を示す。Moreover, the system discrimination signal generation circuit 9 only needs to be installed in one of the color demodulation circuits;
This has the advantage that there is no need to newly provide a terminal for supplying a system discrimination signal between the CAM color demodulation circuits.
FIG. 2 shows a circuit configuration of a specific embodiment of the present invention.
第２図において、第１図のプロツクと同一の符号を付し
た回路は同一の機能を有する。同図において、ＰＡＬ用
色復調回路２１のトランジスタ１０１，１０２，１０３
，１０４，１０５，１０６で構成した２重変衡変調器に
、図示するように搬送色信号と局部搬送波を加えること
によつて、接続点１０７に上記搬送色信号を同期検波し
た色差信号がＰＡＬ信号受信時に得られる。上記接続点
１０７の直流レベルは、電源電圧Ｖ。Ｏから抵抗１０８
の電圧降下分を差し引いた値となる。これは、抵抗１０
８を流れる電流源のトランジスタ１０９のコレクタ電流
の略々半分である。一方、ＳＥＣＡＭ用色復調回路２２
のトランジスタ１１１，１１２，１１３，１１４，１１
５，１１６で構成した２重変衡変調器に、図示するよう
にＦＭ変調されたＳＥＣＡＭ方式の搬送色信号と、その
中心周波数において９０゜移相された信号を加えること
によつて、ＦＭ検波された色差信号が接続点１２０に得
られる。In FIG. 2, circuits with the same reference numerals as the blocks in FIG. 1 have the same functions. In the figure, transistors 101, 102, 103 of the PAL color demodulation circuit 21
, 104, 105, and 106, by adding a carrier color signal and a local carrier wave as shown in the figure, a color difference signal obtained by synchronously detecting the carrier color signal at a connection point 107 is output as a PAL signal. Obtained when receiving a signal. The DC level at the connection point 107 is the power supply voltage V. resistance 108 from O
The value is obtained by subtracting the voltage drop. This is a resistance of 10
This is approximately half of the collector current of the transistor 109 of the current source flowing through the current source. On the other hand, the color demodulation circuit 22 for SECAM
Transistors 111, 112, 113, 114, 11
FM detection is performed by adding an FM-modulated SECAM carrier color signal and a signal phase-shifted by 90° at its center frequency to a double-balanced modulator composed of 5,116 elements as shown in the figure. The resulting color difference signal is obtained at the connection point 120.
その接続点１２０の直流レベルは、電源電圧ＶｃＯより
抵抗１１９の電圧降下分を差し引いた値となる。今、Ｓ
ＥＣＡＭ信号を受信していて、システム判別信号発生回
路９から、トランジスタ１１８を導通せしめるのに十分
ではない出力、例えば接地レベルの信号がトランジスタ
１１８に加わつた場合、電流源トランジスタ１１７は導
通状態にある。The DC level at the connection point 120 is the value obtained by subtracting the voltage drop across the resistor 119 from the power supply voltage VcO. Now, S
When an ECAM signal is being received and an output from the system determination signal generation circuit 9 that is not sufficient to make the transistor 118 conductive, for example, a ground level signal is applied to the transistor 118, the current source transistor 117 is in a conductive state. .
この場合、接続点１２０の直流レベルを、回路のバラツ
キを考慮して、前記ＰＡＬ用色復調回路１０７の直流レ
ベルよりも充分低い電圧にしておく。例えば抵抗１０８
と１１９を同一の値に選び、電流源トランジスタ１１７
のコレクタ電流を電流源トランジスタ１０９のコレクタ
電流の倍に選ぶことによつて、接続点１２０の直流レベ
ルを、接続点１０７の直流レベルより低く選べる。この
場合、コレクタ接地型のＰＮＰ型トランジスタ１２１の
エミツタ電圧は、接続点１２０の直流電圧よりもトラン
ジスタ１２１のエミツタ接合電位だけ高い電圧となる。
トランジスタ１２１のエミツタは色差出力端子１２ある
いは１３と５あるいは６を介して、ＰＡＬ用色復調回路
２１のコレクタ接地形のＰＮＰ型トランジスタ１１０の
エミツタに接続されているので、トランジスタ１１０の
エミツタ直流電圧をトランジスタ１１０のベース偏倚電
圧、すなわち接続点１０７より低くなるように前記接続
点１２０の電圧を設定しておけば、トランジスタ１１０
のエミツタ接合は逆バイアスとなり、トランジスタ１１
０は遮断状態となる。一方、ＰＡＬ信号を受信した場合
、システム判別信号発生回路９から、トランジスタ１１
８を導通状態とするシステム判別信号を供給すれば、電
流源トランジスタ１１７は遮断状態となり、接続点１２
０の直流電圧は電源電圧。In this case, the DC level of the connection point 120 is set to a voltage sufficiently lower than the DC level of the PAL color demodulation circuit 107, taking into account circuit variations. For example, resistor 108
and 119 are selected to have the same value, and the current source transistor 117
By choosing the collector current of current source transistor 109 to be twice the collector current of current source transistor 109, the DC level at node 120 can be chosen to be lower than the DC level at node 107. In this case, the emitter voltage of the common collector PNP transistor 121 is higher than the DC voltage at the connection point 120 by the emitter junction potential of the transistor 121.
The emitter of the transistor 121 is connected to the emitter of the PNP type transistor 110 whose collector is grounded in the PAL color demodulation circuit 21 via the color difference output terminals 12 or 13 and 5 or 6, so that the emitter DC voltage of the transistor 110 is If the voltage at the connection point 120 is set to be lower than the base bias voltage of the transistor 110, that is, the voltage at the connection point 107, the transistor 110
The emitter junction of transistor 11 becomes reverse biased.
0 is a cutoff state. On the other hand, when a PAL signal is received, the transistor 11 is output from the system discrimination signal generation circuit 9.
If a system discrimination signal is supplied that makes the current source transistor 117 conductive, the current source transistor 117 is cut off, and the connection point 12
The DC voltage of 0 is the power supply voltage.
ｏに等しくなり、トランジスタ１２１は遮断状態となる
。このとき、トランジスタ１１０は導通状態になる。な
お、上記実施例においては、システム判別信号発生回路
９はＳＥＣＡＭ用色復調回路２２に含まれているが、Ｐ
ＡＬ用色復調回路２１の方にのみ含めた場合でも同様に
実施でき、同様な効果が得られることは、いうまでもな
い。o, and the transistor 121 is turned off. At this time, transistor 110 becomes conductive. In the above embodiment, the system discrimination signal generation circuit 9 is included in the SECAM color demodulation circuit 22, but P
It goes without saying that even if it is included only in the AL color demodulation circuit 21, it can be implemented in the same way and the same effect can be obtained.
また、実際に本発明を実施する場合、前記ＰＡＬ用色復
調回路２１およびＳＥＣＡＭ用色復調回路２２は集積回
路で構成し得る。Furthermore, when the present invention is actually implemented, the PAL color demodulation circuit 21 and the SECAM color demodulation circuit 22 may be constructed of integrated circuits.
以上の説明から明らかなように、本発明は、一方の色復
調回路、例えばＳＥＣＡＭ用色復調回路内だけに設けた
至つて簡単な回路構成でもつて、ＰＡＬ信号とＳＥＣＡ
Ｍ信号のいずれかを切替え受信し得るもので、その効果
は極めて大きいものがある。As is clear from the above description, the present invention is capable of transmitting PAL signals and SECA signals even with a very simple circuit configuration provided only in one color demodulation circuit, for example, a SECAM color demodulation circuit.
It is possible to switch and receive either of the M signals, and the effect is extremely large.
第１図は本発明の一実施例を示すプロツク図、第２図は
本発明の具体例を示す要部回路構成図である。
１，２・・・・・・同期検波回路、３，４・・・・・・
ＰＡＬ用スイツチ回路、５，６，１２，１３・・・・・
・色差信号出力端子、７，８・・・・・・ＦＭ検波回路
、９・・・・・・システム判別信号発生回路、１０，１
１・・・・・・ＳＥＣＡＭ用スイツチ回路、２１・・・
・・・ＰＡＬ用色復調回路、２２・・・・・・ＳＥＣＡ
Ｍ用色復調回路、１０７，１２０・・・・・・接続点、
１１０，１２１・・・・・・トランジスタ。FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing the main circuit configuration of a specific example of the present invention. 1, 2... Synchronous detection circuit, 3, 4...
PAL switch circuit, 5, 6, 12, 13...
・Color difference signal output terminal, 7, 8... FM detection circuit, 9... System discrimination signal generation circuit, 10, 1
1... SECAM switch circuit, 21...
...PAL color demodulation circuit, 22...SECA
M color demodulation circuit, 107, 120... connection point,
110,121...transistor.
Claims (1)
色復調路およびＳＥＣＡＭ用色復調回路を含み、前記Ｐ
ＡＬ用色復調回路およびＳＥＣＡＭ用色復調回路をそれ
ぞれ別個の集積回路内に集積化し、前記１つの集積回路
内に集積化されたＰＡＬ用色復調回路の同期検波回路と
ＰＡＬ色差信号出力端子の間にはＰＡＬ用スイッチ回路
を設け、他方、別の１つの集積回路内に集積化されたＳ
ＥＣＡＭ用色復調回路のＦＭ検波回路とＳＥＣＡＭ色差
信号出力端子の間にはＳＥＣＡＭ用スイッチ回路を設け
、さらに受信中の信号がＰＡＬ方式とＳＥＣＡＭ方式の
いずれであるかを判明するシステム判別信号発生回路を
設け、このシステム判別信号発生回路を具備せる１つの
集積回路内に集積化されたＳＥＣＡＭ用色復調回路のＳ
ＥＣＡＭ用スイッチ回路の入力直流電圧を１つの集積回
路内に集積化されたＰＡＬ用色復調回路のＰＡＬ用スイ
ッチ回路の一定なる入力直流電圧に対して高電圧あるい
は低電圧になるように変化させて前記スイッチ回路のい
ずれか一方を導通させ、前記共通接続された色差信号出
力端子に、前記システム判別信号発生回路の出力信号に
応じて、ＰＡＬ用色復調回路で処理された色差出力とＳ
ＥＣＡＭ用色復調回路で処理された色差出力のいずれか
一方を選択的に発生させるごとく構成したことを特徴と
する色復調装置。1 includes a PAL color demodulation path and a SECAM color demodulation circuit whose color difference signal output terminals are commonly connected;
An AL color demodulation circuit and a SECAM color demodulation circuit are integrated into separate integrated circuits, and between the synchronous detection circuit of the PAL color demodulation circuit integrated in the one integrated circuit and the PAL color difference signal output terminal. is provided with a PAL switch circuit, and on the other hand, an S
A SECAM switch circuit is provided between the FM detection circuit of the ECAM color demodulation circuit and the SECAM color difference signal output terminal, and a system discrimination signal generation circuit that determines whether the signal being received is PAL or SECAM. S of the color demodulation circuit for SECAM integrated in one integrated circuit equipped with this system discrimination signal generation circuit.
The input DC voltage of the ECAM switch circuit is changed to be a high voltage or a low voltage with respect to the constant input DC voltage of the PAL switch circuit of the PAL color demodulation circuit integrated in one integrated circuit. Either one of the switch circuits is made conductive, and the color difference output processed by the PAL color demodulation circuit and S
A color demodulation device characterized in that it is configured to selectively generate one of the color difference outputs processed by an ECAM color demodulation circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52147837A JPS592435B2 (en) | 1977-12-08 | 1977-12-08 | color demodulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP52147837A JPS592435B2 (en) | 1977-12-08 | 1977-12-08 | color demodulator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5480032A JPS5480032A (en) | 1979-06-26 |
| JPS592435B2 true JPS592435B2 (en) | 1984-01-18 |
Family
ID=15439362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP52147837A Expired JPS592435B2 (en) | 1977-12-08 | 1977-12-08 | color demodulator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS592435B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6386828U (en) * | 1986-11-21 | 1988-06-06 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57171888A (en) * | 1981-04-16 | 1982-10-22 | Mitsubishi Electric Corp | Multisystem color television receiver |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51102517A (en) * | 1975-03-07 | 1976-09-10 | Sony Corp | KARAATEREBIJUZOKINOKIRIKAEHOHO |
| JPS52116113A (en) * | 1976-03-26 | 1977-09-29 | Toshiba Corp | Tv picture receiver |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5440775Y2 (en) * | 1975-01-22 | 1979-11-30 |
-
1977
- 1977-12-08 JP JP52147837A patent/JPS592435B2/en not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51102517A (en) * | 1975-03-07 | 1976-09-10 | Sony Corp | KARAATEREBIJUZOKINOKIRIKAEHOHO |
| JPS52116113A (en) * | 1976-03-26 | 1977-09-29 | Toshiba Corp | Tv picture receiver |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6386828U (en) * | 1986-11-21 | 1988-06-06 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5480032A (en) | 1979-06-26 |
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