JP2515086Y2 - Video intermediate frequency processing circuit - Google Patents
Video intermediate frequency processing circuitInfo
- Publication number
- JP2515086Y2 JP2515086Y2 JP1989026828U JP2682889U JP2515086Y2 JP 2515086 Y2 JP2515086 Y2 JP 2515086Y2 JP 1989026828 U JP1989026828 U JP 1989026828U JP 2682889 U JP2682889 U JP 2682889U JP 2515086 Y2 JP2515086 Y2 JP 2515086Y2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- video
- color
- band
- intermediate frequency
- 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
- H04N9/00—Details of colour television systems
- H04N9/64—Circuits for processing colour signals
- H04N9/647—I.F amplifiers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/60—Receiver circuitry for the reception of television signals according to analogue transmission standards for the sound signals
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Processing Of Color Television Signals (AREA)
- Television Receiver Circuits (AREA)
Description
【考案の詳細な説明】 ［考案の目的］ （産業上の利用分野） 本考案はテレビジョン受像機やビデオテープレコーダ
等に使用される映像中間周波処理回路に係り、特に映像
信号成分の高帯域化，色信号成分の同相歪改善，及び音
声信号成分のバズ軽減化を図った映像中間周波処理回路
に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a video intermediate frequency processing circuit used in a television receiver, a video tape recorder, etc., and particularly to a high band of a video signal component. The present invention relates to a video intermediate frequency processing circuit which is designed to improve the common mode distortion of color signal components and reduce the buzz of audio signal components.
（従来の技術） 従来、テレビジョン受像機等における受信方式の１つ
であるインタキャリア方式では、チューナで周波数変換
された映像キャリア成分と色キャリア成分と音声キャリ
ア成分を一種類の共通通過帯域を有する同一の中間周波
処理回路で増幅及び検波を行っている。従って、インタ
キャリア方式では中間周波処理回路を簡略化できる反
面、例えば映像信号と音声信号との干渉を生じ易い。そ
の為に、音声信号レベルは映像信号レベルより低くし、
また音声信号の映像への混入を防ぐために映像・音声キ
ャリア間のビート周波数に対応した音声トラップを設け
る等している。(Prior Art) Conventionally, in an inter-carrier system, which is one of the receiving systems in a television receiver or the like, a video carrier component, a color carrier component, and an audio carrier component that are frequency-converted by a tuner have a common pass band of one type. Amplification and detection are performed by the same intermediate frequency processing circuit included. Therefore, in the intercarrier system, the intermediate frequency processing circuit can be simplified, but, for example, interference between the video signal and the audio signal is likely to occur. Therefore, the audio signal level should be lower than the video signal level,
In addition, in order to prevent the audio signal from being mixed into the video, an audio trap corresponding to the beat frequency between the video and audio carrier is provided.
第４図は従来の映像中間周波処理回路を示すブロック
図である。FIG. 4 is a block diagram showing a conventional video intermediate frequency processing circuit.
この図において、アンテナ21からのテレビジョン信号
はチューナ22で中間周波信号（以下、IF信号という）に
変換された後、所定の帯域特性を有する弾性表面波フィ
ルタ等のPSF（Picture Surface acoustic wave Filte
r）回路23を通して映像中間周波増幅回路（以下、VIF回
路という）24に供給される。VIF回路24でIF増幅された
信号は、同期検波のためのタンク回路25を有した映像検
波回路（以下、DET回路という）26に供給され、出力端
子28に映像検波出力（コンポジットビデオ出力）を得
る。なお、上記DET回路26と上記VIF回路24間には、映像
検波出力に基づいてIF信号の振幅に比例したAGC電圧を
発生し、映像検波出力を一定するようにVIF回路24のゲ
インを制御するAGC回路27を設けてある。In this figure, a television signal from an antenna 21 is converted into an intermediate frequency signal (hereinafter referred to as an IF signal) by a tuner 22, and then a PSF (Picture Surface acoustic wave Filter) such as a surface acoustic wave filter having a predetermined band characteristic.
r) It is supplied to a video intermediate frequency amplifier circuit (hereinafter referred to as VIF circuit) 24 through a circuit 23. The signal IF-amplified by the VIF circuit 24 is supplied to a video detection circuit (hereinafter referred to as a DET circuit) 26 having a tank circuit 25 for synchronous detection, and a video detection output (composite video output) is output to an output terminal 28. obtain. Note that an AGC voltage proportional to the amplitude of the IF signal is generated between the DET circuit 26 and the VIF circuit 24 based on the video detection output, and the gain of the VIF circuit 24 is controlled so that the video detection output is constant. An AGC circuit 27 is provided.
上記構成において、PSF回路23の帯域特性は第５図
（ａ）に示すようになっている。即ち、色キャリア成分
Ｃのレスポンスは通過帯域内のレスポンスより6dB低下
しており、また音声キャリア成分Ｓのレスポンスは18dB
程低下した特性となっている。そして、出力端子28に得
られるコンポジットビデオ出力の帯域特性は、第５図
（ｂ）に示すように色成分Ｃのレスポンスが低下してい
る。コンポジットビデオ出力は第５図（ｃ）に示すよう
な帯域特性を有した色帯域通過フィルタ（図示せず）を
経て、色成分Ｃが分離される。第５図（ｃ）において斜
線部分は色帯域内に入り込むクロスカラー成分を示して
いる。In the above structure, the band characteristic of the PSF circuit 23 is as shown in FIG. That is, the response of the color carrier component C is 6 dB lower than the response in the pass band, and the response of the voice carrier component S is 18 dB.
The characteristics have deteriorated. Then, in the band characteristic of the composite video output obtained at the output terminal 28, the response of the color component C is lowered as shown in FIG. 5 (b). The composite video output is passed through a color band pass filter (not shown) having a band characteristic as shown in FIG. 5 (c), and the color component C is separated. In FIG. 5 (c), the shaded portion indicates the cross color component that enters the color band.
以上のように構成された従来回路には、次のような問
題がある。The conventional circuit configured as described above has the following problems.
第１に、色キャリア成分の6dB低下により映像帯域が
伸ばし切れず映像キャリア成分の帯域低下を生ずる。第
２に、音声キャリア成分を18dB程低下させているので、
映像キャリア成分の混入によってバズ音が増加し、特に
離調時の音質が悪化する。第３に、色と音声のキャリア
成分によるビートが映像帯域内に入り込み、色・音声ビ
ート妨害として出現してくる。第４に、色成分の同相歪
が大きく、また色帯域内へのクロスカラー成分が大きい
ことである。First, the image carrier cannot be extended due to the decrease of 6 dB in the chrominance carrier component, resulting in a decrease in the image carrier component band. Second, since the voice carrier component is reduced by about 18 dB,
The buzz sound increases due to the mixing of the image carrier component, and the sound quality particularly during detuning deteriorates. Third, beats due to color and audio carrier components enter the video band and appear as color / audio beat interference. Fourth, the common mode distortion of the color components is large, and the cross color component in the color band is large.
（考案が解決しようとする課題） 上記の如く、従来の回路では、映像成分の帯域低下、
音声成分へ混入するバズ音の増加、色・音声成分のキャ
リアビートによる映像帯域へのビート妨害、色成分の同
相歪及び色帯域内へのクロスカラー妨害等の問題があっ
た。(Problems to be Solved by the Invention) As described above, in the conventional circuit, the band of the video component is lowered,
There are problems such as an increase in buzz sound mixed in the audio component, beat interference to the video band due to carrier beats of the color and audio components, in-phase distortion of the color component, and cross color interference within the color band.
そこで、本考案は上記の問題を除去するためのもの
で、映像成分の高帯域化、音声バズ音の軽減、色・音声
ビート妨害の軽減、色成分の同相歪改善及びクロスカラ
ー妨害の改善を図った映像中間周波処理回路を提供する
ことを目的とするものである。Therefore, the present invention is to eliminate the above-mentioned problems, and to improve the band of the video component, reduce the sound buzz sound, reduce the color / voice beat interference, improve the common-mode distortion of the color component, and improve the cross-color interference. It is an object of the present invention to provide an intended video intermediate frequency processing circuit.
［考案の構成］ （課題を解決するための手段） 本考案の映像中間周波処理回路は、色帯域を含む所定
の映像帯域特性を有し、チューナで周波数変換された映
像キャリア成分を通過させる第１の帯域通過フィルタ
と、 所定の色・音声帯域特性を有して、前記チューナで周
波数変換され色・音声キャリア成分を通過させる第２の
帯域通過フィルタと、 平衡入力型の増幅器で構成され、前記第１の帯域通過
フィルタからの映像キャリア成分を増幅する第１の映像
中間周波増幅回路と、 平衡入力型の増幅器で構成され、前記第２の帯域通過
フィルタからの色・音声キャリア成分を増幅する第２の
映像中間周波増幅回路と、 前記第１の映像中間周波増幅回路からの映像キャリア
成分を検波する第１の検波回路と、 前記第２の映像中間周波増幅回路からの色・音声キャ
リア成分を検波する第２の検波回路と、 前記第１の検波回路の出力に基づいてAGC電圧を発生
し、前記第１の映像中間周波増幅回路及び前記第２の映
像中間周波増幅回路の利得を制御するAGC回路とを具備
して構成される。[Configuration of Device] (Means for Solving the Problem) A video intermediate frequency processing circuit of the present invention has a predetermined video band characteristic including a color band, and passes a video carrier component whose frequency is converted by a tuner. 1 band-pass filter, a second band-pass filter having a predetermined color / speech band characteristic and passing a color / speech carrier component that is frequency-converted by the tuner, and a balanced input type amplifier, A first video intermediate frequency amplifier circuit for amplifying a video carrier component from the first band pass filter, and a balanced input type amplifier for amplifying a color / audio carrier component from the second band pass filter. A second video intermediate frequency amplification circuit, a first detection circuit for detecting a video carrier component from the first video intermediate frequency amplification circuit, and a second video intermediate frequency amplification circuit. A second detection circuit for detecting the color / audio carrier components from the above, an AGC voltage is generated based on the output of the first detection circuit, and the first video intermediate frequency amplification circuit and the second video intermediate circuit. And an AGC circuit for controlling the gain of the frequency amplifier circuit.
（作用） 本考案においては、弾性表面波フィルタ等で構成され
る第１の帯域通過フィルタによって、映像キャリア成分
に対しては高帯域型のフィルタ特性を構成し、また同様
に弾性表面波フィルタ等で構成される第２の帯域通過フ
ィルタによって、色・音声キャリア成分に対しては非対
称双峰型の高帯域特性を構成したので、第1,第２のVIF
回路段で映像成分と色・音声成分が互いに干渉すること
がなく、色画質の改善、クロスカラー妨害の改善、音声
のバズ成分の軽減、色・音声ビート妨害の改善を行うこ
とができる。また、VIF回路段の入力方式を、映像処理
用，色・音声処理用ともバランス入力型としたので、外
部からの妨害信号に対する妨害排除性能の改善を図るこ
とができる。更に、IF AGCループについては、映像処理
系と色・音声処理系を同一のAGC電圧で制御するループ
を構成したので、２つの処理系に分離したことによるデ
メリットも改善される。(Operation) In the present invention, the first band-pass filter composed of a surface acoustic wave filter or the like constitutes a high band type filter characteristic for the image carrier component, and similarly, the surface acoustic wave filter or the like. Since the second bandpass filter composed of the above has formed an asymmetric bimodal high-band characteristic for the chromatic / voice carrier component, the first and second VIF
It is possible to improve the color image quality, improve cross color interference, reduce the buzz component of audio, and improve color / audio beat interference without the video component and the color / audio component interfering with each other in the circuit stage. Further, since the input method of the VIF circuit stage is a balanced input type for both video processing and color / audio processing, it is possible to improve the interference rejection performance against an interference signal from the outside. Further, as for the IF AGC loop, since the loop for controlling the video processing system and the color / audio processing system with the same AGC voltage is configured, the demerit of separating into two processing systems is also improved.
（実施例） 以下、図面に示した実施例に基づいて本考案を説明す
る。(Embodiment) Hereinafter, the present invention will be described based on an embodiment shown in the drawings.
第１図は本考案の一実施例の映像中間周波処理回路を
示すブロック図である。FIG. 1 is a block diagram showing a video intermediate frequency processing circuit according to an embodiment of the present invention.
この図において、アンテナ１からのテレビジョン信号
はチューナ２にて周波数変換されIF信号となって映像処
理用の第１の表面波フィルタ（以下、PSF−１回路とい
う）３に入力すると同時に、色・音声処理用の第２の表
面波フィルタ（以下、PSF−２回路という）４に入力す
る。PSF−１回路３及びPSF−２回路４の帯域特性はそれ
ぞれ第３図（ａ）及び（ｂ）に示すようになっている。
PSF−１回路３を通過したIF信号は第１の映像中間周波
増幅回路（以下、VIF−１回路という）５を経て、同期
検波を行うためのタンク回路６を有した映像検波回路
（以下、DET−１回路という）７に入り、その出力端子
８に映像検波出力（コンポジットビデオ出力）を得る。
上記DET−１回路７とVIF−１回路５との間には、IF信号
の振幅に比例したAGC電圧を発生してVIF−１回路５のゲ
インを御するAGC回路９が設けてある。一方、PSF−２回
路４を通過したIF信号は第２の映像中間周波増幅回路
（以下、VIF−２回路という）10を経て、検波回路（以
下、DET−２回路という）11に入り、その出力端子12に
色・音声の検波出力を得る。なお、上記AGC回路９のAGC
電圧はVIF−２回路10のゲインを制御するのにも使用さ
れる。In this figure, a television signal from an antenna 1 is frequency-converted by a tuner 2 to become an IF signal, which is input to a first surface wave filter (hereinafter referred to as PSF-1 circuit) 3 for image processing, and at the same time, a color signal is input. -Input to the second surface wave filter (hereinafter referred to as PSF-2 circuit) 4 for voice processing. The band characteristics of the PSF-1 circuit 3 and the PSF-2 circuit 4 are as shown in FIGS. 3 (a) and 3 (b), respectively.
The IF signal that has passed through the PSF-1 circuit 3 passes through a first video intermediate frequency amplification circuit (hereinafter, referred to as VIF-1 circuit) 5 and a video detection circuit (hereinafter, referred to as a tank detection circuit 6 having a tank circuit 6 for performing synchronous detection. A DET-1 circuit) 7 is entered, and an image detection output (composite video output) is obtained at its output terminal 8.
An AGC circuit 9 is provided between the DET-1 circuit 7 and the VIF-1 circuit 5 to control the gain of the VIF-1 circuit 5 by generating an AGC voltage proportional to the amplitude of the IF signal. On the other hand, the IF signal that has passed through the PSF-2 circuit 4 passes through a second video intermediate frequency amplifier circuit (hereinafter referred to as VIF-2 circuit) 10 and enters a detection circuit (hereinafter referred to as DET-2 circuit) 11, A color / voice detection output is obtained at the output terminal 12. The AGC of the above AGC circuit 9
The voltage is also used to control the gain of the VIF-2 circuit 10.
上記VIF−１回路５及び上記VIF−２回路10としては、
両回路とも第２図（ａ）に示すような平衡（バランス）
入力型の増幅器を用いる。第２図（ａ）において、VIF
増幅器は、差動対を成す２つのトランジスタQ1,Q2と、
トランジスタQ1,Q2の共通エミッタに接続したトランジ
スタQ3と、トランジスタQ1,Q2の各コレクタと電源端子1
6間に接続した抵抗R1,R2と、トランジスタQ3のエミッタ
と基準電位点間に接続した抵抗R3とで構成されている。
なお、電源端子16には直流電源＋Vccを接続している。
トランジスタQ1,Q2のベースに接続した入力端子13,14に
はPSF−１回路３又はPSF−２回路４からの信号を入力
し、トランジスタQ3のベースに接続した端子15にはAGC
電圧を入力し、トランジスタQ1,Q2のコレクタに接続し
た出力端子17,18から増幅信号を取り出し次段のDET−１
回路７又はDET−２回路11に供給する。なお、以上述べ
たバランス入力型の増幅器に対してアンバランス入力型
増幅器とは、第２図（ｂ）に示すようなトランジスタQ
4,抵抗R4,R5から成る増幅器を指している。As the VIF-1 circuit 5 and the VIF-2 circuit 10,
Both circuits are balanced as shown in Fig. 2 (a).
An input type amplifier is used. In Fig. 2 (a), VIF
The amplifier includes two transistors Q1 and Q2 that form a differential pair,
Transistor Q3 connected to the common emitter of transistors Q1 and Q2, collectors of transistors Q1 and Q2, and power supply terminal 1
It is composed of resistors R1 and R2 connected between 6 and a resistor R3 connected between the emitter of the transistor Q3 and the reference potential point.
A DC power supply + Vcc is connected to the power supply terminal 16.
The signals from the PSF-1 circuit 3 or PSF-2 circuit 4 are input to the input terminals 13 and 14 connected to the bases of the transistors Q1 and Q2, and the AGC is input to the terminal 15 connected to the base of the transistor Q3.
Input the voltage and take out the amplified signal from the output terminals 17 and 18 connected to the collectors of the transistors Q1 and Q2.
It is supplied to the circuit 7 or the DET-2 circuit 11. An unbalanced input type amplifier, as opposed to the balanced input type amplifier described above, is a transistor Q as shown in FIG.
An amplifier consisting of 4, resistors R4 and R5.
第３図は第１図の回路各部における帯域特性を示すも
のである。第３図（ａ）は上記PSF−１回路３の映像帯
域特性を示している。この特性は、第５図に示したPSF
回路の特性に比し、色キャリア成分Ｃの帯域にまで伸び
た高帯域型の特性となっている。また、第３図（ｂ）は
上記PSF−２回路４の帯域特性を示し、色キャリア成分
Ｃ及び音声キャリア成分Ｓの帯域を含む非対称双峰型の
高帯域型特性となっている。第３図（ｃ）は上記DET−
１回路７の出力レスポンスであり、（ａ）の特性に対応
して映像成分が高帯域化されている。第３図（ｄ）は上
記DET−２回路11の出力レスポンスであり、（ｂ）の特
性に対応して点線に示すような出力レスポンスが得られ
る。第３図（ｄ）において実線は色帯域成分、一点鎖線
は音声帯域成分であり、斜線部分が色帯域に入り込むク
ロスカラー成分（輝度信号の高域成分等）を示してい
る。FIG. 3 shows band characteristics in each part of the circuit shown in FIG. FIG. 3A shows the video band characteristic of the PSF-1 circuit 3. This characteristic is the PSF shown in Fig. 5.
Compared with the circuit characteristics, it has a high band type characteristic that extends to the band of the color carrier component C. Further, FIG. 3 (b) shows the band characteristic of the PSF-2 circuit 4, which has an asymmetric bimodal high band type characteristic including the bands of the color carrier component C and the voice carrier component S. Figure 3 (c) shows the above DET-
This is an output response of one circuit 7, and the video component has a high band corresponding to the characteristic of (a). FIG. 3D shows the output response of the DET-2 circuit 11, and the output response shown by the dotted line is obtained corresponding to the characteristic of FIG. In FIG. 3 (d), the solid line indicates the color band component, the alternate long and short dash line indicates the voice band component, and the shaded portion indicates the cross color component (high-frequency component of the luminance signal, etc.) that enters the color band.
以上の構成においては、PSF−１回路３とPSF−１回路
４とで映像キャリア成分と色・音声キャリア成分を分離
処理し、各々独立した帯域フィルタを形成させることに
より、両成分が互いに干渉するのを軽減することができ
る。これによって映像成分の高帯域化、色・音声成分の
分離処理による色の高画質化（同相歪の軽減及びクロス
カラー妨害の改善）、音声成分に混入するバズ成分の軽
減化を実現できる。In the above configuration, the PSF-1 circuit 3 and the PSF-1 circuit 4 separate the video carrier component and the color / audio carrier component to form independent band filters, so that both components interfere with each other. Can be reduced. As a result, it is possible to increase the band of the video component, improve the image quality of the color by separating the color and audio components (reduce common-mode distortion and improve cross-color interference), and reduce the buzz component mixed in the audio component.
さらに、第２図に示した如くVIF段の入力方式を映像
処理段，色・音声処理段共に、バランス型の入力形態と
することにより、外部からの妨害信号に対する妨害排除
性能の改善を図ることができる。IF AGCループについて
も、映像処理段と、色・音声処理段を同一のAGC電圧に
て制御することにより、同一形式のAGCループにてゲイ
ンの同一化を図ることができ、分離処理による不利益を
生じることが無い。Furthermore, as shown in Fig. 2, the input method of the VIF stage is a balanced type input method for both the video processing stage and the color / audio processing stage to improve the interference rejection performance against interference signals from the outside. You can Also for the IF AGC loop, by controlling the video processing stage and the color / audio processing stage with the same AGC voltage, the gain can be made the same in the same type of AGC loop, which is a disadvantage due to separation processing. Does not occur.
［考案の効果］ 以上述べたように本考案によれば、映像処理と色・音
声処理を分離し、かつ各VIF段をバランス入力型とした
ので、映像成分の高帯域化が可能となりこれによって解
像度の向上を図ることができる。また、色成分に対する
同相歪の改善及びクロスカラー妨害の改善、音声成分へ
のバズ音の軽減、色・音声ビート妨害の改善などを図る
ことが可能となる。従って、テレビジョン受像機等の映
像機器の高画質化を実現することができる。[Advantages of the Invention] As described above, according to the present invention, the video processing and the color / audio processing are separated, and each VIF stage is of the balanced input type, so that the bandwidth of the video component can be increased, thereby The resolution can be improved. In addition, it is possible to improve common-mode distortion for color components, improve cross-color interference, reduce buzz to audio components, and improve color / audio beat interference. Therefore, it is possible to realize high image quality of video equipment such as a television receiver.
第１図は本考案の一実施例の映像中間周波処理回路を示
すブロック図、第２図は第１図の映像中間周波増幅回路
に用いるバランス入力型増幅器を説明する回路図、第３
図は第１図の要部における帯域特性を説明する説明図、
第４図は従来の映像中間周波処理回路を示すブロック
図、第５図は第４図の要部における帯域特性を説明する
説明図である。 ２……チューナ、３……第１のPSF回路、４……第２のP
SF回路、５……第１のVIF回路、７……第１のDET回路、
８……映像出力端子、９……AGC回路、10……第２のVIF
回路、11……第２のDET回路、12……色・音声出力端
子。1 is a block diagram showing a video intermediate frequency processing circuit of an embodiment of the present invention, FIG. 2 is a circuit diagram illustrating a balanced input type amplifier used in the video intermediate frequency amplifying circuit of FIG. 1, and FIG.
The figure is an explanatory view for explaining the band characteristic in the main part of FIG.
FIG. 4 is a block diagram showing a conventional video intermediate frequency processing circuit, and FIG. 5 is an explanatory diagram for explaining the band characteristic in the main part of FIG. 2 ... tuner, 3 ... first PSF circuit, 4 ... second PF
SF circuit, 5 ... first VIF circuit, 7 ... first DET circuit,
8 ... video output terminal, 9 ... AGC circuit, 10 ... second VIF
Circuit, 11 …… Second DET circuit, 12 …… Color / audio output terminal.
Claims (1)
チューナで周波数変換された映像キャリア成分を通過さ
せる第１の帯域通過フィルタと、 所定の色・音声帯域特性を有し、前記チューナで周波数
変換され色・音声キャリア成分を通過させる第２の帯域
通過フィルタと、 平衡入力型の増幅器で構成され、前記第１の帯域通過フ
ィルタからの映像キャリア成分を増幅する第１の映像中
間周波増幅回路と、 平衡入力型の増幅器で構成され、前記第２の帯域通過フ
ィルタからの色・音声キャリア成分を増幅する第２の映
像中間周波増幅回路と、 前記第１の映像中間周波増幅回路回路からの映像キャリ
ア成分を検波する第１の検波回路と、 前記第２の映像中間周波増幅回路からの色・音声キャリ
ア成分を検波する第２の検波回路と、 前記第１の検波回路の出力に基づいてAGC電圧を発生
し、前記第１の映像中間周波増幅回路及び前記第２の映
像中間周波増幅回路の利得を制御するAGC回路と、 を具備したことを特徴とする映像中間周波処理回路。1. A predetermined video band characteristic including a color band,
A first band-pass filter for passing a video carrier component whose frequency is converted by a tuner; and a second band-pass which has a predetermined color / audio band characteristic and passes a color / audio carrier component whose frequency is converted by the tuner. A first video intermediate frequency amplifier circuit configured by a filter, a balanced input type amplifier for amplifying a video carrier component from the first band-pass filter, and a balanced input type amplifier by the second video intermediate frequency amplifier circuit. A second video intermediate frequency amplification circuit for amplifying a color / audio carrier component from the band pass filter; a first detection circuit for detecting the video carrier component from the first video intermediate frequency amplification circuit circuit; A second detection circuit for detecting color / audio carrier components from the second video intermediate frequency amplification circuit; and an AGC voltage generated based on the output of the first detection circuit, Video intermediate frequency processing circuit, characterized in that it comprises a and a AGC circuit for controlling the gain of the video intermediate frequency amplifying circuit and the second video intermediate frequency amplifier circuit.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989026828U JP2515086Y2 (en) | 1989-03-08 | 1989-03-08 | Video intermediate frequency processing circuit |
| GB9003614A GB2229877B (en) | 1989-03-08 | 1990-02-16 | Video intermediate frequency processing circuit |
| DE4006059A DE4006059A1 (en) | 1989-03-08 | 1990-02-26 | VIDEO INTERFACE PROCESSING CIRCUIT |
| KR1019900002911A KR940010614B1 (en) | 1989-03-08 | 1990-03-06 | Image intermediate frequency signal processing unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989026828U JP2515086Y2 (en) | 1989-03-08 | 1989-03-08 | Video intermediate frequency processing circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02118373U JPH02118373U (en) | 1990-09-21 |
| JP2515086Y2 true JP2515086Y2 (en) | 1996-10-23 |
Family
ID=12204133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1989026828U Expired - Lifetime JP2515086Y2 (en) | 1989-03-08 | 1989-03-08 | Video intermediate frequency processing circuit |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP2515086Y2 (en) |
| KR (1) | KR940010614B1 (en) |
| DE (1) | DE4006059A1 (en) |
| GB (1) | GB2229877B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6542725B2 (en) | 1996-05-15 | 2003-04-01 | Thomson Licensing S.A. | Amplifier circuit arrangement for alternatively processing a digital or an analog signal |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR743694A (en) * | 1931-12-26 | 1933-04-03 | ||
| GB460675A (en) * | 1935-11-27 | 1937-02-02 | Gen Electric Co Ltd | Improvements in or relating to television receivers and the like |
| US3787612A (en) * | 1972-07-03 | 1974-01-22 | Zenith Radio Corp | Signal processing system for television receiver having acoustic surface wave devices for improved tuning and video demodulation |
| NL7300370A (en) * | 1973-01-12 | 1974-07-12 | ||
| JPS5816652B2 (en) * | 1975-09-09 | 1983-04-01 | ソニー株式会社 | Jiyushinki |
| JPS54154889A (en) * | 1978-05-26 | 1979-12-06 | Kobe Steel Ltd | Punching device for marking machine |
| US4660087A (en) * | 1986-02-28 | 1987-04-21 | Rca Corporation | Video signal processing system with offset sound trap |
| US4718086A (en) * | 1986-03-27 | 1988-01-05 | Rca Corporation | AGC in sound channel of system for processing a scrambled video signal |
| JP2675550B2 (en) * | 1987-03-31 | 1997-11-12 | 株式会社東芝 | Intermediate frequency processing circuit |
-
1989
- 1989-03-08 JP JP1989026828U patent/JP2515086Y2/en not_active Expired - Lifetime
-
1990
- 1990-02-16 GB GB9003614A patent/GB2229877B/en not_active Expired - Fee Related
- 1990-02-26 DE DE4006059A patent/DE4006059A1/en active Granted
- 1990-03-06 KR KR1019900002911A patent/KR940010614B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| GB9003614D0 (en) | 1990-04-11 |
| KR940010614B1 (en) | 1994-10-24 |
| GB2229877B (en) | 1993-09-01 |
| KR900015525A (en) | 1990-10-27 |
| GB2229877A (en) | 1990-10-03 |
| JPH02118373U (en) | 1990-09-21 |
| DE4006059A1 (en) | 1990-09-20 |
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