JPH01161986A - Color signal processing circuit - Google Patents

Color signal processing circuit

Info

Publication number
JPH01161986A
JPH01161986A JP62318960A JP31896087A JPH01161986A JP H01161986 A JPH01161986 A JP H01161986A JP 62318960 A JP62318960 A JP 62318960A JP 31896087 A JP31896087 A JP 31896087A JP H01161986 A JPH01161986 A JP H01161986A
Authority
JP
Japan
Prior art keywords
limiter
signal
color
output
missing
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.)
Pending
Application number
JP62318960A
Other languages
Japanese (ja)
Inventor
Yoshihiro Deguchi
出口 芳弘
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP62318960A priority Critical patent/JPH01161986A/en
Publication of JPH01161986A publication Critical patent/JPH01161986A/en
Pending legal-status Critical Current

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  • Processing Of Color Television Signals (AREA)

Abstract

PURPOSE:To obtain a color signal with less missing of color even if the feedback rate of a recursive filter component is increased or the improving effect of the S/N is increased by selecting optimizingly the character of a limiter in use. CONSTITUTION:A chroma signal is fed from an input terminal IN and added to an original chroma signal by an adder 3 via a delay device 2. In the selection of a delay of the delay device 2 is selected, e.g., as one horizontal scanning period(1H), a signal retarded by 1H at a color non-correlation section is fed to a limiter 4, and in the selection of the characteristic of the limiter 4, the limiter passes a signal below the limiter level and a signal over the limiter level is selected to a cause 0 or gradual 0, then as the output signal from the limiter 4, the signal with large amplitude with remarkable color missing is made nearly zero. Thus, the output is fed to a subtractor 1 via a coefficient device 5 with a feedback coefficient K2, then the output of the limiter 4 is almost zero in a large amplitude having a color whose missing is eminent in color missing. Thus, the color signal without color missing is obtained.

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等の磁気記録再生回路
に利用される色信号処理回路に関する。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color signal processing circuit used in a magnetic recording/reproducing circuit such as a video tape recorder.

(従来の技術) 近年、テレビや、ビデオテープレコーダの分野では、記
録カラー画像の高画質化の要求が高まってきている。
(Prior Art) In recent years, in the field of televisions and video tape recorders, there has been an increasing demand for higher quality recorded color images.

第2図は上述の高画質化技術の一例の1色信号を処理す
るためのクロマリカーシブ回路である。
FIG. 2 shows a chroma recursive circuit for processing a single color signal as an example of the above-mentioned high image quality technology.

1は第1の減算器、2は遅延器、3は加算器、4はリミ
ッタで、その特性は第3図の特性を有する。また5は帰
還係数に2の係数器、6は帰還係数(ミックス比)K□
の係数器、7は第2の減算器である。このように構成さ
れたクロマリカーシブ回路は次のように動作する。
1 is a first subtracter, 2 is a delay device, 3 is an adder, and 4 is a limiter, the characteristics of which are shown in FIG. Also, 5 is a feedback coefficient of 2, and 6 is a feedback coefficient (mix ratio) K□
, and 7 is the second subtractor. The chroma recursive circuit configured in this manner operates as follows.

まず、クロマ信号が入力端子INから印加されると、遅
延器2により遅延されて原クロマ信号と加算器3により
加算され、第2図のような一般のリミッタ特性を有する
リミッタ4により、リミッタレベル以下の成分をとり出
して帰還係数に2の係数器5を介してに2倍し、前記減
算器1によって原クロマ信号との差をとって垂直方向の
くし形特性にさせ、リミッタ4の出力を帰還係数に8の
係数器6を通し、減算器7を用いて原クロマ信号から減
算し出力とする。
First, when a chroma signal is applied from the input terminal IN, it is delayed by a delay device 2, added to the original chroma signal by an adder 3, and then set to a limiter level by a limiter 4 having general limiter characteristics as shown in FIG. The following components are extracted and multiplied by 2 through the feedback coefficient 2 coefficient multiplier 5, and the difference from the original chroma signal is taken by the subtracter 1 to create a vertical comb characteristic, and the limiter 4 outputs is passed through a coefficient unit 6 of 8 as a feedback coefficient, and subtracted from the original chroma signal using a subtracter 7 to output the result.

このような構成によって係数器5の帰還係数に2の値を
大きくして帰還率をあげていくと、クロマ信号のくし形
特性が急峻となり、クロマ信号の平担部のS/N比を改
善することができる。
With this configuration, when the feedback coefficient of the coefficient unit 5 is increased to a value of 2 to increase the feedback rate, the comb characteristic of the chroma signal becomes steeper, and the S/N ratio of the flat part of the chroma signal is improved. can do.

(発明が解決しようとする問題点) しかしながら、上記の構成では、クロマ信号のS/N比
を改善するためにリカーシブのくし形特性を急峻にして
、帰還特性を向上させると、色の非相関部では第2図の
特性のダイオードにより構成される一般のリミッタを使
用しているため、非相関部の色の遅延@2による遅れ分
が一定として出力され、それが帰還係数に2の係数器5
を介して入力側に帰還されるため、さらに色落ちが大き
くなるという問題点が生じていた。
(Problem to be Solved by the Invention) However, in the above configuration, if the recursive comb characteristic is made steeper to improve the S/N ratio of the chroma signal and the feedback characteristic is improved, the color uncorrelation Since the section uses a general limiter consisting of a diode with the characteristics shown in Figure 2, the delay due to the color delay @2 of the non-correlation section is output as a constant, and it is used as the feedback coefficient by the coefficient multiplier of 2. 5
Since the color is fed back to the input side via the filter, there has been a problem that color fading becomes even greater.

本発明は上記の問題点を排除して、リミッタ特性を適当
にすることによって、色落ちを改善する色信号処理回路
の提供を目的とするものである。
An object of the present invention is to eliminate the above-mentioned problems and provide a color signal processing circuit that improves color fading by optimizing limiter characteristics.

(問題点を解決するための手段) 上記の問題点を解決するため本発明は色信号処理回路に
おいて、リミッタレベル以下の信号を通過させ、それ以
上の信号はOまたは徐々に0とする特性のリミッタを使
用することによって解決する。
(Means for Solving the Problems) In order to solve the above problems, the present invention provides a color signal processing circuit with a characteristic in which signals below the limiter level are passed through, and signals above the limit are set to 0 or gradually become 0. Solved by using a limiter.

(作 用) 上記の構成により本発明は、クロマ信号のS/Nを改善
するために遅延器で構成されるリカーシブフィルタの帰
還率を高めることにより、くし形特性を急峻にさせても
1色落ちの少ない色信号処理回路が形成される。
(Function) With the above configuration, the present invention improves the S/N ratio of the chroma signal by increasing the feedback rate of the recursive filter composed of a delay device, so that even if the comb characteristic is made steep, one color can be processed. A color signal processing circuit with less dropout is formed.

(実施例) 以下、本発明の色信号処理回路を実施例によって前出第
2図を用いて説明する。
(Embodiment) Hereinafter, the color signal processing circuit of the present invention will be explained by way of an embodiment using FIG. 2 mentioned above.

第2図構成の色信号処理回路において、まず、入力端子
INからクロマ信号が印加され、遅延器2を経て加算器
3により原クロマ信号と加算される。ここで遅延器2の
遅延量を、たとえば1水平走査期間(以下、IHと略す
)とすれば1色の非相関部では、1H遅れた信号がリミ
ッタ4に印加されるが、このとき、リミッタ4の特性を
第1図のように、リミッタレベル以下の信号は通過させ
、それ以上の信号を0または徐々に0とする特性にして
おけば、色の非相関部で生ずるIH遅れた信号も、リミ
ッタレベル以下の信号のみを通過させ。
In the color signal processing circuit shown in FIG. 2, first, a chroma signal is applied from an input terminal IN, passes through a delay device 2, and is added to the original chroma signal by an adder 3. Here, if the delay amount of the delay device 2 is, for example, one horizontal scanning period (hereinafter abbreviated as IH), a signal delayed by 1H is applied to the limiter 4 in the uncorrelated part of one color. If the characteristics of 4 are set as shown in Figure 1, in which signals below the limiter level are passed through and signals above it are 0 or gradually become 0, IH-delayed signals that occur in uncorrelated areas of colors can also be eliminated. , only passes signals below the limiter level.

それ以上のレベルの信号は出力されないことになるから
、リミッタ4の出力信号としては、色落ちが目立つ色の
大振幅の信号は殆どOとなる。したがって、その出力を
帰還係数に2の係数器5を経て減算器1に印加すれば1
色落ちの目立つ色の大振幅信号においては、リミッタ4
の出力は殆どOとなり、従来のような色落ちの部分が帰
還されることはなくなる。すなわち色落ちが改善される
から、上記のリミッタ4の出力を係数器6によりK、倍
し、減算器7で原人カクロマ信号と減算させて色落ちの
少ない色信号を得ることができる。
Since a signal with a level higher than that will not be outputted, the output signal of the limiter 4 is almost O for a large amplitude signal of a color with noticeable color fading. Therefore, if the output is applied to the subtracter 1 through the coefficient unit 5 of 2 as a feedback coefficient, 1
For large amplitude signals with noticeable color fading, use limiter 4.
The output is almost O, and discolored parts are no longer fed back as in the conventional case. That is, since the color fading is improved, the output of the limiter 4 is multiplied by K by the coefficient multiplier 6, and subtracted from the original person's color signal by the subtracter 7, thereby obtaining a color signal with less color fading.

(発明の効果) 以上説明して明らかなよう′に本発明は、リカーシブ回
路により構成する色信号処理回路において、それに用い
るリミッタの特性を最適に選ぶことによって、リカーシ
ブフィルタ構成部分の帰還率を上げてS/N比の改善効
果をよくしても1色落ちが少ない色信号が得られる効果
がある。
(Effects of the Invention) As is clear from the above explanation, the present invention improves the feedback rate of the recursive filter component by optimally selecting the characteristics of the limiter used in the color signal processing circuit constituted by the recursive circuit. Even if the S/N ratio is improved, a color signal with less color loss can be obtained.

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

第1図は本発明に用いるリミッタの特性の一例を示す図
、第2図は本発明の一実施例回路を示すブロック図、第
3図は一般のリミッタ特性を示す図である。 1.7・・・減算器、2・・・遅延器、3・・・加算器
、4・・・ リミッタ、5,6・・・係数器。 特許出願人 松下電器産業株式会社 第1図 第2図 3・・77II+簿農    4  ソミッタ5.6・
 ll!F、*x 第3図
FIG. 1 is a diagram showing an example of the characteristics of a limiter used in the present invention, FIG. 2 is a block diagram showing an embodiment of the circuit of the present invention, and FIG. 3 is a diagram showing the characteristics of a general limiter. 1.7...Subtractor, 2...Delay unit, 3...Adder, 4...Limiter, 5,6...Coefficient unit. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 2 Figure 3... 77II + Bookkeeping 4 Somitta 5.6.
ll! F, *x Figure 3

Claims (1)

【特許請求の範囲】[Claims] 入力信号を遅延させる遅延器と、この遅延器出力と入力
信号との和をとる加算器と、その加算器の出力をリミッ
タレベル以下の信号は通過させ、リミッタレベル以上の
信号入力を0とするか、または徐々に0とするリミッタ
と、前記リミッタの出力をK_2倍する第1の係数器と
、その係数器出力と入力信号との差をとる第1の減算器
と、上記リミッタの出力をK_1倍する第2の係数器と
、その出力と入力信号との差をとる第2の減算器とによ
り構成したことを特徴とする色信号処理回路。
A delay device that delays the input signal, an adder that takes the sum of the output of this delay device and the input signal, and a signal that is below the limiter level is passed through the output of the adder, and a signal that is input above the limiter level is set to 0. or a limiter that gradually sets the output to 0, a first coefficient multiplier that multiplies the output of the limiter by K_2, a first subtractor that takes the difference between the output of the coefficient multiplier and the input signal, and 1. A color signal processing circuit comprising a second coefficient multiplier that multiplies by K_1 and a second subtracter that takes the difference between its output and an input signal.
JP62318960A 1987-12-18 1987-12-18 Color signal processing circuit Pending JPH01161986A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62318960A JPH01161986A (en) 1987-12-18 1987-12-18 Color signal processing circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62318960A JPH01161986A (en) 1987-12-18 1987-12-18 Color signal processing circuit

Publications (1)

Publication Number Publication Date
JPH01161986A true JPH01161986A (en) 1989-06-26

Family

ID=18104913

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62318960A Pending JPH01161986A (en) 1987-12-18 1987-12-18 Color signal processing circuit

Country Status (1)

Country Link
JP (1) JPH01161986A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61228792A (en) * 1985-04-03 1986-10-11 Matsushita Electric Ind Co Ltd Chrominance signal processor
JPS61247193A (en) * 1985-04-25 1986-11-04 Matsushita Electric Ind Co Ltd Comb line filter

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61228792A (en) * 1985-04-03 1986-10-11 Matsushita Electric Ind Co Ltd Chrominance signal processor
JPS61247193A (en) * 1985-04-25 1986-11-04 Matsushita Electric Ind Co Ltd Comb line filter

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