JPH07135577A - Television receiver provided with scanning speed modulation circuit and contour emphasis circuit including the modulation circuit - Google Patents

Television receiver provided with scanning speed modulation circuit and contour emphasis circuit including the modulation circuit

Info

Publication number
JPH07135577A
JPH07135577A JP27943093A JP27943093A JPH07135577A JP H07135577 A JPH07135577 A JP H07135577A JP 27943093 A JP27943093 A JP 27943093A JP 27943093 A JP27943093 A JP 27943093A JP H07135577 A JPH07135577 A JP H07135577A
Authority
JP
Japan
Prior art keywords
circuit
scanning speed
speed modulation
output
signal
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
JP27943093A
Other languages
Japanese (ja)
Inventor
Kenichi Matsumoto
健一 松本
Kazuhiro Kaizaki
一洋 海崎
Akira Ueno
彰 上野
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.)
Hitachi Image Information Systems Inc
Hitachi Ltd
Hitachi Advanced Digital Inc
Original Assignee
Hitachi Image Information Systems Inc
Hitachi Ltd
Hitachi Video and Information System Inc
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 Hitachi Image Information Systems Inc, Hitachi Ltd, Hitachi Video and Information System Inc filed Critical Hitachi Image Information Systems Inc
Priority to JP27943093A priority Critical patent/JPH07135577A/en
Publication of JPH07135577A publication Critical patent/JPH07135577A/en
Pending legal-status Critical Current

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  • Picture Signal Circuits (AREA)
  • Details Of Television Scanning (AREA)

Abstract

PURPOSE:To prevent power consumption from being considerably increased even when a signal having lots of high frequency components such as a noise is received by a scanning speed modulation circuit 100 being a component of a video image contour emphasis circuit. CONSTITUTION:A video signal received at an input terminal 10 is processed by a scanning speed modulation signal processing circuit 20 and amplified by a variable gain amplifier circuit 30 and an amplifier circuit 40 and the amplified signal is fed to a scanning speed modulation coil 200 by an output circuit 50 to emphasize a contour of a video image. A current detection circuit 70 detects a mean current of the output circuit and a comparator circuit 80 compares the current with a reference voltage. When the former exceeds the latter as the result of comparison, the gain of the amplifier circuit 30 is reduced to suppress a current flowing to the output circuit 50.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、陰極線管表示装置に表
示する映像の輪郭強調を行う輪郭強調回路を備えたテレ
ビジョン受信機に関するものであり、更に詳しくは、か
かる輪郭強調回路を構成する構成要素としての走査速度
変調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 a television receiver provided with a contour emphasizing circuit for emphasizing the contour of an image displayed on a cathode ray tube display device, and more specifically, it constitutes such a contour emphasizing circuit. The present invention relates to a scanning speed modulation circuit as a constituent element.

【0002】[0002]

【従来の技術】テレビ画像の鮮鋭度を向上して画質の改
善を図る方法の一つとして、特公昭55−37903号
公報で開示されている如き、一定速度で走査する陰極線
管電子ビームの走査速度の変調を行い、陰極線管に表示
する映像の輪郭強調を行う走査速度変調方式が知られて
いる。この方式は、陰極線管電子ビームにおいて、その
走査速度を速めたところでは画像が暗くなり、走査速度
を遅くしたところでは画像が明るくなる事を利用したも
ので、ビーム電流を上げずに明るくすることができるた
め、ビームスポット径の増大による解像度劣化がない。
2. Description of the Related Art As one of the methods for improving the sharpness of a television image and improving the image quality, as described in Japanese Patent Publication No. 55-37903, the scanning of a cathode ray tube electron beam for scanning at a constant speed. A scanning speed modulation method is known in which the speed is modulated to enhance the contour of an image displayed on a cathode ray tube. This method utilizes the fact that in a cathode ray tube electron beam, the image becomes darker when the scanning speed is increased and becomes brighter when the scanning speed is slowed down. Therefore, the resolution does not deteriorate due to the increase of the beam spot diameter.

【0003】ここで、映像の輪郭強調を行う輪郭強調回
路として、上記の如き、従来の走査速度変調方式を採る
輪郭強調回路を備えたテレビジョン受信機の構成を、図
2を用いて説明する。同図において、0は入力端子、1
00は走査速度変調回路、200は走査速度変調コイ
ル、300は映像信号処理回路、400はビデオ回路、
500は陰極線管カソード、600は陰極線管(ブラウ
ン管)である。
Here, the configuration of a television receiver including the above-described contour enhancement circuit adopting the conventional scanning velocity modulation method as a contour enhancement circuit for enhancing the contour of an image will be described with reference to FIG. . In the figure, 0 is an input terminal, 1
00 is a scanning speed modulation circuit, 200 is a scanning speed modulation coil, 300 is a video signal processing circuit, 400 is a video circuit,
Reference numeral 500 is a cathode ray tube cathode, and 600 is a cathode ray tube (Braun tube).

【0004】図2において、入力端子0に入力された映
像信号は、映像信号処理回路300で種々の所要の映像
信号処理を施され、ビデオ回路400で増幅され、ブラ
ウン管600のカソード500に入力され画像として映
し出される。また、入力端子0に入力された映像信号を
走査速度変調回路100に入力して、走査速度変調コイ
ル200に加える走査速度変調信号を作成する。
In FIG. 2, the video signal input to the input terminal 0 is subjected to various required video signal processing in the video signal processing circuit 300, amplified in the video circuit 400, and input to the cathode 500 of the cathode ray tube 600. It is displayed as an image. In addition, the video signal input to the input terminal 0 is input to the scanning speed modulation circuit 100 to create a scanning speed modulation signal to be applied to the scanning speed modulation coil 200.

【0005】特公昭55−37903号公報では、映像
信号を2次微分した信号を走査速度変調コイルに印加
し、輪郭強調のための補正電流として流してやること
で、上記の走査速度変調方式による輪郭強調を実現して
いる。その具体的方法を図3を用いて簡潔に説明する。
なお図3は、図2における各部信号の波形を示す信号波
形図である。
In Japanese Patent Publication No. 55-37903, a signal obtained by quadratic differentiation of a video signal is applied to a scanning velocity modulation coil, and is supplied as a correction current for enhancing the contour, whereby the contour according to the above scanning velocity modulation method is applied. The emphasis is realized. The specific method will be briefly described with reference to FIG.
3 is a signal waveform diagram showing the waveform of each signal in FIG.

【0006】図2、図3を参照する。入力端子0に図3
の(a)に示すような映像信号が入力されたとき、走査
速度変調コイル200に、図3の(b)に示すような信
号を印加し、図3の(c)に示すような補正電流を流す
ことにより、ブラウン管600上での映像の輝度変化
は、図3の(d)に示すようになる。ここで、(b)は
映像信号(a)の2次微分波形、(c)は映像信号
(a)の1次微分波形となっている。この結果、映像の
輪郭が強調され、鮮鋭度が向上する。
Please refer to FIG. 2 and FIG. Input terminal 0
When a video signal as shown in (a) is input, a signal as shown in (b) of FIG. 3 is applied to the scanning velocity modulation coil 200, and a correction current as shown in (c) of FIG. 3 is applied. As a result, the luminance change of the image on the cathode ray tube 600 becomes as shown in FIG. Here, (b) is the secondary differential waveform of the video signal (a), and (c) is the primary differential waveform of the video signal (a). As a result, the contour of the image is emphasized and the sharpness is improved.

【0007】[0007]

【発明が解決しようとする課題】さて特公昭55−37
903号公報で開示された走査速度変調回路では、例え
ば、入力端子0にノイズ等の高周波成分を多く含む映像
信号を入力すると、補正電流の実効値が大きくなり、消
費電力が大幅に増大するという問題があった。ここでノ
イズ等の高周波成分を多く含む映像信号としては、弱電
界時のテレビジョン信号とか、マルチバースト測定時に
測定器から出力されてテレビ受信機に印加される測定の
ための信号(ノイズではないのだが、高周波成分を多く
含む信号)などがある。
[Problems to be Solved by the Invention] Japanese Patent Publication No. 55-37
In the scanning velocity modulation circuit disclosed in Japanese Patent No. 903, for example, when a video signal containing a large amount of high frequency components such as noise is input to the input terminal 0, the effective value of the correction current increases and the power consumption significantly increases. There was a problem. Here, a video signal containing a lot of high-frequency components such as noise is a television signal in a weak electric field, or a signal for measurement output from a measuring instrument during multiburst measurement and applied to a television receiver (not noise However, there are many high-frequency components) and so on.

【0008】特公昭55−37903号公報では、この
高周波成分による消費電力増大の問題については特に述
べられておらず、配慮されていなかった。本発明では、
かかる問題について配慮し、ノイズ等の高周波成分の多
い信号が入力されたときでも、消費電力が大幅に増大す
ることのない走査速度変調回路及び該変調回路を含む輪
郭強調回路を備えたテレビジョン受信機を提供すること
を目的とする。
Japanese Examined Patent Publication No. 55-37903 does not particularly mention or consider the problem of increase in power consumption due to the high frequency component. In the present invention,
Considering such a problem, a television receiver including a scanning speed modulation circuit and a contour enhancement circuit including the modulation circuit, which does not significantly increase power consumption even when a signal having many high frequency components such as noise is input. The purpose is to provide a machine.

【0009】[0009]

【課題を解決するための手段】上記目的達成のため、本
発明では、陰極線管表示装置に電子ビームの走査速度を
変調するための変調コイルを設けておき、該陰極線管表
示装置に映像を表示する際、走査速度変調回路から、そ
こで作成した走査速度変調信号を前記変調コイルに供給
して流すことにより、前記陰極線管表示装置に表示され
た映像の輪郭部の強調を行う輪郭強調回路における前記
走査速度変調回路として、
In order to achieve the above object, the present invention provides a cathode ray tube display device with a modulation coil for modulating the scanning speed of an electron beam, and displays an image on the cathode ray tube display device. In this case, the scanning speed modulation circuit supplies the scanning speed modulation signal created therein to the modulation coil to flow the signal, thereby enhancing the contour portion of the image displayed on the cathode ray tube display device. As a scanning speed modulation circuit,

【0010】表示すべき前記映像信号から前記走査速度
変調信号を作り出す走査速度変調信号処理回路と、該走
査速度変調信号処理回路の出力信号である走査速度変調
信号を増幅する可変利得増幅回路と、該可変利得増幅回
路の出力信号を増幅する増幅回路と、該増幅回路からの
増幅出力を前記変調コイルに供給して流してやるための
出力回路と、前記出力回路の出力電流を検出する電流検
出回路と、該電流検出回路による電流検出値と所与の基
準電圧値を比較する比較回路と、比較の結果、電流検出
値が基準電圧値を超えた場合に、前記可変利得増幅回路
の利得を低下させる利得制御手段と、から成る走査速度
変調回路を提案すると共に、かかる走査速度変調回路を
含む輪郭強調回路を備えたテレビジョン受信機を提案し
た。
A scanning speed modulation signal processing circuit for generating the scanning speed modulation signal from the video signal to be displayed, and a variable gain amplifier circuit for amplifying the scanning speed modulation signal which is an output signal of the scanning speed modulation signal processing circuit, An amplifier circuit for amplifying an output signal of the variable gain amplifier circuit, an output circuit for supplying an amplified output from the amplifier circuit to the modulation coil and causing it to flow, and a current detection circuit for detecting an output current of the output circuit. And a comparison circuit for comparing a current detection value by the current detection circuit with a given reference voltage value, and a gain of the variable gain amplification circuit is reduced when the current detection value exceeds the reference voltage value as a result of the comparison. The present invention proposes a scanning speed modulation circuit including the gain control means for controlling the gain control means, and a television receiver provided with a contour enhancement circuit including the scanning speed modulation circuit.

【0011】[0011]

【作用】本発明によれば、走査速度変調回路において、
ノイズ等の高周波成分の多い映像信号が入力されたとき
に、出力回路に流れる電流を抑制でき、消費電力が大幅
に増大することはない。
According to the present invention, in the scanning speed modulation circuit,
When a video signal having many high frequency components such as noise is input, the current flowing through the output circuit can be suppressed, and the power consumption does not increase significantly.

【0012】[0012]

【実施例】以下、本発明の実施例を図面を参照して説明
する。図1は、本発明の一実施例としての走査速度変調
回路を示すブロック図である。同図において、100S
は本発明による走査速度変調回路、10は入力端子、2
0は走査速度変調信号処理回路、30は可変利得増幅回
路、40は増幅回路、50は出力回路、70は電流検出
回路、80は比較回路、200は走査速度変調コイル、
である。
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a scanning speed modulation circuit as an embodiment of the present invention. In the figure, 100S
Is a scanning speed modulation circuit according to the present invention, 10 is an input terminal, 2 is
0 is a scanning speed modulation signal processing circuit, 30 is a variable gain amplification circuit, 40 is an amplification circuit, 50 is an output circuit, 70 is a current detection circuit, 80 is a comparison circuit, 200 is a scanning speed modulation coil,
Is.

【0013】図3は、先に図2における各部信号の波形
を示す信号波形図であると説明したが、図1に示す本発
明の実施例における各部信号の波形を説明するのにも役
立つ信号波形図であるので、以下、図1、図3を参照し
て回路動作を説明する。
Although FIG. 3 has been described above as a signal waveform diagram showing the waveform of each part signal in FIG. 2, a signal useful for explaining the waveform of each part signal in the embodiment of the present invention shown in FIG. Since it is a waveform diagram, the circuit operation will be described below with reference to FIGS. 1 and 3.

【0014】入力端子10に入力された映像信号(図3
の(a))は、走査速度変調信号処理回路20で所要の
信号処理を施され、図3の信号(b)となる。この信号
(b)は、可変利得増幅回路30および増幅回路40で
増幅されて、出力回路50によって、走査速度変調コイ
ル200に印加される。この時、走査速度変調コイル2
00には、図3の(c)に示すような電流が流れ、ブラ
ウン管600上(図2)での映像の輝度変化は、図3
(d)に示すようになり、映像の輪郭強調が行える。
A video signal input to the input terminal 10 (see FIG.
3 (a) is subjected to necessary signal processing by the scanning speed modulation signal processing circuit 20 and becomes the signal (b) in FIG. This signal (b) is amplified by the variable gain amplifier circuit 30 and the amplifier circuit 40, and is applied to the scanning speed modulation coil 200 by the output circuit 50. At this time, the scanning velocity modulation coil 2
A current as shown in (c) of FIG. 3 flows through 00, and the luminance change of the image on the cathode ray tube 600 (FIG. 2) is as shown in FIG.
As shown in (d), the contour of the image can be emphasized.

【0015】そして、電流検出回路70で出力回路50
に流れる平均電流を検出し、比較回路80で別に定めた
基準電圧値(図示せず)と比較する。この比較の結果、
平均電流検出値が基準電圧値より小さい場合は、可変利
得増幅回路30の利得制御は行なわないが、平均電流検
出値が基準電圧値を越えたとき、可変利得増幅回路30
の利得を低下させることにより、走査速度変調コイル2
00に印加する信号振幅を低下させ、出力回路50に流
れる電流を抑制する。
The current detection circuit 70 outputs the output circuit 50.
The average current flowing through the circuit is detected and compared with a reference voltage value (not shown) separately determined by the comparison circuit 80. As a result of this comparison,
When the average current detection value is smaller than the reference voltage value, the gain control of the variable gain amplification circuit 30 is not performed, but when the average current detection value exceeds the reference voltage value, the variable gain amplification circuit 30 is not.
Scanning speed modulation coil 2 by reducing the gain of
The amplitude of the signal applied to 00 is reduced, and the current flowing through the output circuit 50 is suppressed.

【0016】ここで、平均電流検出値が基準電圧値を越
える場合について説明する。図1において、入力端子1
0にノイズ等の高周波成分の多い信号が入力されると、
走査速度変調コイル200には、図4に示す如き波形の
電流が流れ、電流の実効値が増大する。ここで図4は、
走査速度変調回路にノイズ等の高周波成分の多い信号が
入力されたときに、走査速度変調コイルに流れる電流波
形の一例を示す波形図である。
The case where the average current detection value exceeds the reference voltage value will be described. In FIG. 1, the input terminal 1
When a signal with many high frequency components such as noise is input to 0,
A current having a waveform as shown in FIG. 4 flows through the scanning velocity modulation coil 200, and the effective value of the current increases. Here, in FIG.
It is a waveform diagram which shows an example of the current waveform which flows into a scanning velocity modulation coil, when the signal with many high frequency components, such as noise, is input into the scanning velocity modulation circuit.

【0017】このため、図1において、電流検出回路7
0で検出される平均電流検出値も増大し、基準電圧値を
越えることになる。このようなときに、可変利得増幅回
路30の利得を低下させることにより、走査速度変調コ
イル200に印加する信号振幅を低下させ、出力回路5
0に流れる電流を抑制する。こうして消費電力の増大を
大幅に抑えることができる。
Therefore, in FIG. 1, the current detection circuit 7
The average current detection value detected at 0 also increases and exceeds the reference voltage value. In such a case, by decreasing the gain of the variable gain amplifier circuit 30, the amplitude of the signal applied to the scanning speed modulation coil 200 is decreased and the output circuit 5
The current flowing to 0 is suppressed. In this way, an increase in power consumption can be significantly suppressed.

【0018】図5は、図1における走査速度変調信号処
理回路20の具体例を示すブロック図である。図5にお
いて、21はLC微分回路、22もLC微分回路であ
る。図5に示すように、走査速度変調信号処理回路20
は、簡単な2次微分回路で構成できる。
FIG. 5 is a block diagram showing a specific example of the scanning speed modulation signal processing circuit 20 in FIG. In FIG. 5, 21 is an LC differentiating circuit, and 22 is also an LC differentiating circuit. As shown in FIG. 5, the scanning speed modulation signal processing circuit 20
Can be constructed by a simple second order differentiating circuit.

【0019】図6は、本発明の一実施例としての走査速
度変調回路の具体例を示す回路図である。この回路図
は、図1に示すブロック図において、可変利得増幅回路
30、増幅回路40、出力回路50、走査速度変調コイ
ル200、電流検出回路70、および、比較回路80の
部分に相当する回路図である。以下、この回路例の動作
を説明する。
FIG. 6 is a circuit diagram showing a specific example of the scanning speed modulation circuit as an embodiment of the present invention. This circuit diagram corresponds to the variable gain amplifier circuit 30, the amplifier circuit 40, the output circuit 50, the scanning speed modulation coil 200, the current detection circuit 70, and the comparison circuit 80 in the block diagram shown in FIG. Is. The operation of this circuit example will be described below.

【0020】図6において、電流検出抵抗器71及び平
滑コンデンサ72で、出力トランジスタ52のコレクタ
電流の平均値を電圧に変換し、その電圧値(以下、平均
電流検出値と呼ぶ)を、定電圧源81で定めた基準電圧
値と比較する。平均電流検出値が基準電圧値より小さい
場合は、トランジスタ33はカットオフ状態となり、図
中破線で囲まれた可変利得増幅回路30の利得は、トラ
ンジスタ31、32と抵抗器34、35で決定される。
In FIG. 6, the current detection resistor 71 and the smoothing capacitor 72 convert the average value of the collector current of the output transistor 52 into a voltage, and the voltage value (hereinafter referred to as the average current detection value) is converted into a constant voltage. The reference voltage value determined by the source 81 is compared. When the average current detection value is smaller than the reference voltage value, the transistor 33 is in a cutoff state, and the gain of the variable gain amplifier circuit 30 surrounded by the broken line in the figure is determined by the transistors 31 and 32 and the resistors 34 and 35. It

【0021】平均電流検出値が基準電圧値を越えると、
トランジスタ33に電流が流れはじめ、可変利得増幅回
路30の利得が低下し、走査速度変調コイル200に印
加する信号振幅が低下し、出力トランジスタ51、52
に流れる電流が抑制される。この例では、抵抗器82,
83の抵抗値を変えることで、可変利得増幅回路30の
可変感度を容易に調節することができる。
When the average current detection value exceeds the reference voltage value,
The current starts to flow through the transistor 33, the gain of the variable gain amplifier circuit 30 decreases, the amplitude of the signal applied to the scanning speed modulation coil 200 decreases, and the output transistors 51 and 52 are output.
The electric current flowing through is suppressed. In this example, resistors 82,
By changing the resistance value of 83, the variable sensitivity of the variable gain amplifier circuit 30 can be easily adjusted.

【0022】以上説明した本発明にかかる走査速度変調
回路を含む輪郭強調回路を備えたテレビジョン受信機の
実施例は、図2において、その走査速度変調回路100
を本発明にかかる走査速度変調回路に置き換えることに
より容易に実現できるので、これ以上の説明は不要であ
ろう。
The embodiment of the television receiver provided with the contour enhancement circuit including the scanning speed modulation circuit according to the present invention described above is shown in FIG.
Can be easily realized by substituting the scanning speed modulation circuit according to the present invention with, so further explanation will be unnecessary.

【0023】[0023]

【発明の効果】本発明によれば、テレビジョン受信機等
の輪郭強調回路を構成する走査速度変調回路において、
ノイズ等の高周波成分の多い信号が入力されたときに、
出力回路に流れる電流を抑制でき、消費電力を低減でき
る。従って、出力回路のトランジスタの電力損失も低減
されるので、出力回路のトランジスタに、安価な素子を
使用できる利点もある。
According to the present invention, in a scanning speed modulation circuit which constitutes an outline emphasis circuit of a television receiver or the like,
When a signal with many high frequency components such as noise is input,
The current flowing through the output circuit can be suppressed and power consumption can be reduced. Therefore, the power loss of the transistor of the output circuit is also reduced, and there is an advantage that an inexpensive element can be used for the transistor of the output circuit.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例としての走査速度変調回路を
示すブロック図である。
FIG. 1 is a block diagram showing a scanning speed modulation circuit as an embodiment of the present invention.

【図2】走査速度変調回路を含む映像輪郭強調回路を備
えたテレビジョン受信機の構成例を示すブロック図であ
る。
FIG. 2 is a block diagram showing a configuration example of a television receiver including a video contour enhancement circuit including a scanning speed modulation circuit.

【図3】図1又は図2に示す走査速度変調回路の各部動
作波形を示す信号波形図である。
3 is a signal waveform diagram showing operation waveforms of respective parts of the scanning speed modulation circuit shown in FIG. 1 or FIG.

【図4】高周波成分の多い信号が入力されたときの走査
速度変調コイルの電流波形例を示す波形図である。
FIG. 4 is a waveform diagram showing an example of a current waveform of the scanning velocity modulation coil when a signal having many high frequency components is input.

【図5】図1における走査速度変調信号処理回路の具体
例を示すブロック図である。
5 is a block diagram showing a specific example of a scanning speed modulation signal processing circuit in FIG.

【図6】本発明の一実施例としての走査速度変調回路の
具体例を示す回路図である。
FIG. 6 is a circuit diagram showing a specific example of a scanning speed modulation circuit as an embodiment of the present invention.

【符号の説明】[Explanation of symbols]

20…走査速度変調信号処理回路、21,22…LC微
分回路、30…可変利得増幅回路、31,32,33,
51,52…トランジスタ、34,35,71,82,
83…抵抗器、40…増幅回路、50…出力回路、72
…コンデンサ、81…定電圧源、70…電流検出回路、
80…比較回路、100…走査速度変調回路、100S
…本発明による走査速度変調回路、200…走査速度変
調コイル、300…映像信号処理回路、400…ビデオ
回路、500…カソード、600…ブラウン管
20 ... Scan speed modulation signal processing circuit, 21, 22 ... LC differentiating circuit, 30 ... Variable gain amplifying circuit, 31, 32, 33,
51, 52 ... Transistors, 34, 35, 71, 82,
83 ... Resistor, 40 ... Amplifying circuit, 50 ... Output circuit, 72
... Capacitor, 81 ... Constant voltage source, 70 ... Current detection circuit,
80 ... Comparison circuit, 100 ... Scanning speed modulation circuit, 100S
... scan speed modulation circuit according to the present invention, 200 ... scan speed modulation coil, 300 ... video signal processing circuit, 400 ... video circuit, 500 ... cathode, 600 ... cathode ray tube

───────────────────────────────────────────────────── フロントページの続き (72)発明者 海崎 一洋 神奈川県横浜市戸塚区吉田町292番地 株 式会社日立製作所情報映像メディア事業部 内 (72)発明者 上野 彰 神奈川県横浜市戸塚区吉田町292番地 株 式会社日立画像情報システム内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Umizaki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Information & Video Media Division (72) Akira Ueno Yoshida, Totsuka-ku, Yokohama-shi, Kanagawa 292, Machi Incorporated company Hitachi Image Information System

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 陰極線管表示装置に電子ビームの走査速
度を変調するための変調コイルを設けておき、該陰極線
管表示装置に映像を表示する際、走査速度変調回路か
ら、そこで作成した走査速度変調信号を前記変調コイル
に供給して流すことにより、前記陰極線管表示装置に表
示された映像の輪郭部の強調を行う輪郭強調回路におけ
る前記走査速度変調回路であって、 表示すべき前記映像信号から前記走査速度変調信号を作
り出す走査速度変調信号処理回路と、該走査速度変調信
号処理回路の出力信号である走査速度変調信号を増幅す
る可変利得増幅回路と、該可変利得増幅回路の出力信号
を増幅する増幅回路と、該増幅回路からの増幅出力を前
記変調コイルに供給して流してやるための出力回路と、
前記出力回路の出力電流を検出する電流検出回路と、該
電流検出回路による電流検出値と所与の基準電圧値を比
較する比較回路と、比較の結果、電流検出値が基準電圧
値を超えた場合に、前記可変利得増幅回路の利得を低下
させる利得制御手段と、から成ることを特徴とする走査
速度変調回路。
1. A cathode-ray tube display device is provided with a modulation coil for modulating the scanning speed of an electron beam, and when an image is displayed on the cathode-ray tube display device, a scanning speed created by the scanning speed modulation circuit thereat. The scanning speed modulation circuit in a contour enhancement circuit for enhancing a contour portion of an image displayed on the cathode ray tube display device by supplying a modulation signal to the modulation coil and causing the modulation signal to flow. A scanning speed modulation signal processing circuit for generating the scanning speed modulation signal from the scanning speed modulation signal processing circuit, a variable gain amplification circuit for amplifying the scanning speed modulation signal which is an output signal of the scanning speed modulation signal processing circuit, and an output signal of the variable gain amplification circuit. An amplifying circuit for amplifying, and an output circuit for supplying the amplified output from the amplifying circuit to the modulation coil and letting it flow.
A current detection circuit that detects the output current of the output circuit, a comparison circuit that compares the current detection value of the current detection circuit with a given reference voltage value, and the comparison result shows that the current detection value exceeds the reference voltage value. In this case, the scanning speed modulation circuit comprises: a gain control means for reducing the gain of the variable gain amplification circuit.
【請求項2】 請求項1に記載の走査速度変調回路にお
いて、前記電流検出回路が、前記出力回路を構成する出
力トランジスタのコレクタに流れる電流を検出する回路
から成ることを特徴とする走査速度変調回路。
2. The scanning speed modulation circuit according to claim 1, wherein the current detection circuit includes a circuit that detects a current flowing through a collector of an output transistor that constitutes the output circuit. circuit.
【請求項3】 請求項1又は2に記載の走査速度変調回
路を含む輪郭強調回路を備えたことを特徴とするテレビ
ジョン受信機。
3. A television receiver comprising an edge enhancement circuit including the scanning speed modulation circuit according to claim 1. Description:
JP27943093A 1993-11-09 1993-11-09 Television receiver provided with scanning speed modulation circuit and contour emphasis circuit including the modulation circuit Pending JPH07135577A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP27943093A JPH07135577A (en) 1993-11-09 1993-11-09 Television receiver provided with scanning speed modulation circuit and contour emphasis circuit including the modulation circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP27943093A JPH07135577A (en) 1993-11-09 1993-11-09 Television receiver provided with scanning speed modulation circuit and contour emphasis circuit including the modulation circuit

Publications (1)

Publication Number Publication Date
JPH07135577A true JPH07135577A (en) 1995-05-23

Family

ID=17610965

Family Applications (1)

Application Number Title Priority Date Filing Date
JP27943093A Pending JPH07135577A (en) 1993-11-09 1993-11-09 Television receiver provided with scanning speed modulation circuit and contour emphasis circuit including the modulation circuit

Country Status (1)

Country Link
JP (1) JPH07135577A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010051428A (en) * 1999-11-05 2001-06-25 톰슨 라이센싱 에스.에이. Signal processing for scanning beam velocity modulation
JP2013187559A (en) * 2012-03-05 2013-09-19 Asahi Kasei Electronics Co Ltd Pulse generation circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010051428A (en) * 1999-11-05 2001-06-25 톰슨 라이센싱 에스.에이. Signal processing for scanning beam velocity modulation
JP2013187559A (en) * 2012-03-05 2013-09-19 Asahi Kasei Electronics Co Ltd Pulse generation circuit

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