JPH0695768B2 - Image quality switching circuit of television receiver - Google Patents
Image quality switching circuit of television receiverInfo
- Publication number
- JPH0695768B2 JPH0695768B2 JP60157280A JP15728085A JPH0695768B2 JP H0695768 B2 JPH0695768 B2 JP H0695768B2 JP 60157280 A JP60157280 A JP 60157280A JP 15728085 A JP15728085 A JP 15728085A JP H0695768 B2 JPH0695768 B2 JP H0695768B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- switching circuit
- circuit
- video
- image quality
- 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
Landscapes
- Processing Of Color Television Signals (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明はビデオ入力端子を有するテレビジョン受像機の
画質切換回路に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image quality switching circuit of a television receiver having a video input terminal.
従来の技術 近年、テレビジョン受像機にビデオ入力端子を有するも
のが多くなっており、ビデオ機器が接続できるようにな
ってきた。ビデオ入力信号は、通常の放送信号の様に帯
域制限を受けないため、テレビジョン受像機では周波数
特性を改善し、解像度の向上は目ざましいものである。2. Description of the Related Art In recent years, many television receivers have a video input terminal, and a video device can be connected. Since the video input signal is not subject to band limitation like a normal broadcast signal, the frequency characteristic is improved and the resolution is remarkably improved in the television receiver.
第２図は従来のビデオ切換回路を示す。10はRF入力のテ
レビ放送信号、11はビデオ入力端子より入力されるビデ
オ信号、12はCRTに表示するためのドライブ信号、13は
テレビ放送信号10を検波しビデオ帯域にする検波回路、
14は検波回路13出力のテレビ信号と前記ビデオ信号11と
の切換える入力切換回路、15は切換えられた信号の周波
数特性補正回路である。FIG. 2 shows a conventional video switching circuit. 10 is an RF input TV broadcast signal, 11 is a video signal input from a video input terminal, 12 is a drive signal for displaying on a CRT, 13 is a detection circuit that detects the TV broadcast signal 10 and converts it into a video band,
Reference numeral 14 is an input switching circuit for switching between the television signal output from the detection circuit 13 and the video signal 11, and 15 is a frequency characteristic correction circuit for the switched signal.
この様な回路で、ビデオ入力端子から入力されたビデオ
信号11の周波数特性を改善して、解像度を向上させてい
る。With such a circuit, the frequency characteristic of the video signal 11 input from the video input terminal is improved to improve the resolution.
発明が解決しようとする問題点 このような従来の構成では、帯域制限をうけたテレビ信
号も、周波数特性補正回路15を通り、周波数特性を伸ば
すことになる。テレビ信号は、ビデオ入力端子から入力
される信号の様に、特性の安定した信号ではなく、種々
の電波状況により位相特性などさまざまであり、リンギ
ングなど多い信号もある。この信号を周波数特性補正回
路15で周波数特性をのばせば、ドット妨害などが強調さ
れ、逆に画質が悪化するという問題点を有していた。Problems to be Solved by the Invention With such a conventional configuration, a television signal subjected to band limitation also passes through the frequency characteristic correction circuit 15 to extend the frequency characteristic. A TV signal is not a signal having stable characteristics like a signal input from a video input terminal, but has various phase characteristics such as phase characteristics depending on various radio wave conditions, and some signals include ringing. If the frequency characteristic correction circuit 15 extends the frequency characteristic of the signal, dot interference or the like is emphasized, and conversely the image quality deteriorates.
本発明は入力切換回路でテレビ放送信号を選択した時に
CRTで再生される画像の画質を改善することができ、し
かも入力切換回路でビデオ入力信号を選択した時にCRT
で再生される画像の画質を悪化させることがない画質切
換回路を提供することを目的とする。The present invention is applied when a television broadcast signal is selected by the input switching circuit.
It is possible to improve the image quality of the image reproduced by the CRT, and when the video input signal is selected by the input switching circuit, the CRT
It is an object of the present invention to provide an image quality switching circuit which does not deteriorate the image quality of an image reproduced by.
問題点を解決するための手段 本発明の画質切換回路は、検波されてビデオ帯域に変換
されたテレビ信号とビデオ入力端子よりのビデオ入力信
号との一方を切換回路で選択して出力するよう構成する
と共に、前記切換回路の出力のビデオ信号をクロマ信号
と輝度信号に分離する信号分離回路と、搬送色信号成分
を除去するトラップ回路とを設け、前記切換回路の切換
に連動してテレビ信号側を選択時に前記トラップ回路が
前記信号分離回路の輝度信号出力ラインに挿入されるよ
う構成したことを特徴とする。The image quality switching circuit of the present invention is configured so that the switching circuit selects and outputs one of a television signal detected and converted into a video band and a video input signal from a video input terminal. In addition, a signal separation circuit for separating the video signal output from the switching circuit into a chroma signal and a luminance signal, and a trap circuit for removing the carrier color signal component are provided, and the television signal side is linked with the switching of the switching circuit. Is selected, the trap circuit is inserted into the luminance signal output line of the signal separation circuit.
作用 この構成によると、入力切換回路でテレビ放送信号側を
選択した時に輝度信号にトラップを挿入するため、ビデ
オ入力信号を選択した時の周波数特性を劣化させること
なく、テレビ信号のドット妨害を軽減できる。Effect With this configuration, a trap is inserted in the luminance signal when the TV broadcast signal side is selected by the input switching circuit, so the dot interference of the TV signal is reduced without degrading the frequency characteristics when the video input signal is selected. it can.
実施例 以下、本発明の一実施例第１図に基づいて説明する。Embodiment An embodiment of the present invention will be described below with reference to FIG.
テレビ放送信号１は検波回路６で検波されてビデオ帯域
信号となり、入力切換回路７において、ビデオ入力端子
から入力されたビデオ信号２と切り換えられる。切換え
られた信号は、コムフィルタ等の輝度信号とクロマ信号
の分離回路８によりクロマ信号３と輝度信号４とに分離
される。一方、入力切換回路７で生じる切換信号５を利
用し、スイッチング用のトランジスタＱをテレビ放送受
像時のみ導通させて3.58MHzのトラップ９を、輝度信号
４の出力ラインに挿入する。The television broadcast signal 1 is detected by the detection circuit 6 to be a video band signal, and is switched to the video signal 2 input from the video input terminal by the input switching circuit 7. The switched signal is separated into a chroma signal 3 and a luminance signal 4 by a luminance signal and chroma signal separation circuit 8 such as a comb filter. On the other hand, by utilizing the switching signal 5 generated in the input switching circuit 7, the switching transistor Q is made conductive only when the television broadcast is received, and the 3.58 MHz trap 9 is inserted in the output line of the luminance signal 4.
このようにしたため、ビデオ入力端子より入力された帯
域制限を受けないビデオ信号は周波数特性の良い信号と
して処理され、一方、テレビ放送信号は検波回路６でも
周波数特性補正が行なわれ入力切換回路７以降でさらに
周波数特性補正が行なわれドット妨害は大きくなるが、
この約3.58MHzのトラップ９によりドット妨害を軽減で
きる。As a result, the video signal inputted from the video input terminal which is not subject to band limitation is processed as a signal having a good frequency characteristic, while the television broadcast signal is also subjected to frequency characteristic correction by the detection circuit 6 and the input switching circuit 7 and thereafter. In addition, the frequency characteristic is corrected and the dot interference increases, but
This 3.58 MHz trap 9 can reduce dot interference.
発明の効果 以上説明のように本発明のテレビジョン受像機の画質切
換回路は、入力切換回路でテレビ放送信号側を選択した
ときにだけ輝度信号に搬送波色信号成分を除去するトラ
ップを挿入し、ビデオ入力信号側を選択したときには前
記トラップを挿入しない回路構成であるため、ビデオ入
力信号側を選択したときの周波数特性を劣化させること
がなく、ビデオ入力信号の画質を変えることなく（悪化
させることなく）テレビ放送信号側を選択したときのド
ット妨害を軽減してCRTで再生される画像の画質を改善
することができる。As described above, the image quality switching circuit of the television receiver of the present invention inserts the trap for removing the carrier color signal component in the luminance signal only when the television broadcasting signal side is selected by the input switching circuit, Since the circuit configuration does not insert the trap when the video input signal side is selected, the frequency characteristic when the video input signal side is selected is not deteriorated and the image quality of the video input signal is not changed (deteriorated). It is possible to reduce the dot interference when the TV broadcast signal side is selected and improve the image quality of the image reproduced by the CRT.
第１図は本発明の画質切換回路の一実施例のブロック
図、第２図は従来のビデオ切換回路のブロック図であ
る。 １……テレビ放送信号、２……ビデオ入力信号、４……
輝度信号、６……検波回路、７……入力切換回路、８…
…輝度・クロマ信号分離回路、９……3.58MHzトラッ
プ、Ｑ……スイッチングトランジスタFIG. 1 is a block diagram of an embodiment of an image quality switching circuit of the present invention, and FIG. 2 is a block diagram of a conventional video switching circuit. 1 ... TV broadcast signal, 2 ... video input signal, 4 ...
Luminance signal, 6 ... Detection circuit, 7 ... Input switching circuit, 8 ...
… Brightness / chroma signal separation circuit, 9 …… 3.58MHz trap, Q …… Switching transistor
Claims (2)
信号とビデオ入力端子よりのビデオ入力信号との一方を
切換回路で選択して出力するよう構成すると共に、前記
切換回路の出力のビデオ信号をクロマ信号と輝度信号に
分離する信号分離回路と、搬送色信号成分を除去するト
ラップ回路とを設け、前記切換回路の切換に連動してテ
レビ信号側を選択時に前記トラップ回路が前記信号分離
回路の輝度信号出力カラインに挿入されるよう構成した
テレビジョン受像機の画質切換回路。1. A switching circuit selects and outputs one of a television signal detected and converted into a video band and a video input signal from a video input terminal, and a video signal output from the switching circuit. Is provided with a signal separation circuit for separating the chroma signal and the luminance signal, and a trap circuit for removing the carrier color signal component. When the television signal side is selected in association with the switching of the switching circuit, the trap circuit is the signal separation circuit. The image quality switching circuit of the television receiver configured to be inserted in the luminance signal output line of.
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
ョン受像機の画質切換回路。2. An image quality switching circuit for a television receiver according to claim 1, wherein the trap circuit is a 3.58 MHz trap.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60157280A JPH0695768B2 (en) | 1985-07-17 | 1985-07-17 | Image quality switching circuit of television receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60157280A JPH0695768B2 (en) | 1985-07-17 | 1985-07-17 | Image quality switching circuit of television receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6218892A JPS6218892A (en) | 1987-01-27 |
| JPH0695768B2 true JPH0695768B2 (en) | 1994-11-24 |
Family
ID=15646205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60157280A Expired - Lifetime JPH0695768B2 (en) | 1985-07-17 | 1985-07-17 | Image quality switching circuit of television receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0695768B2 (en) |
-
1985
- 1985-07-17 JP JP60157280A patent/JPH0695768B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6218892A (en) | 1987-01-27 |
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