JPH03173271A - Cathode ray tube device - Google Patents

Cathode ray tube device

Info

Publication number
JPH03173271A
JPH03173271A JP31376889A JP31376889A JPH03173271A JP H03173271 A JPH03173271 A JP H03173271A JP 31376889 A JP31376889 A JP 31376889A JP 31376889 A JP31376889 A JP 31376889A JP H03173271 A JPH03173271 A JP H03173271A
Authority
JP
Japan
Prior art keywords
crt
voltage
vertical deflection
vertical
electron beam
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
JP31376889A
Other languages
Japanese (ja)
Inventor
Susumu Niino
新納 進
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP31376889A priority Critical patent/JPH03173271A/en
Publication of JPH03173271A publication Critical patent/JPH03173271A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To attain a CRT device not giving a damage to the CRT at a fault by providing a means detecting a vertical deflection voltage and a means relinquishing an electron beam of the CRT when the detected voltage is lower than a prescribed value. CONSTITUTION:Suppose that a vertical coupling capacitor 7 is short-circuited, a DC current of a waveform shown in waveform diagram (b) flows to a vertical deflection coil and an electron beam 12 is concentrated onto the upper part of a CRT 11. Let an impedance of a feedback resistor 8 be 1.5 ohm and a DC resistance of the vertical deflection coil be 6 ohms, then a DC current flowing from a vertical output transistor (TR) 13a causes a voltage of nearly 3V across the resistor 8 and a cathode-anode voltage of a Zener diode 4 reaches 7V or over. In this embodiment, since the Zener diode whose Zener diode voltage is 7V is employed, the current flows from the cathode to the anode, a TR 2 is turned on, a mute signal is sent to a video mute circuit 15, the video signal is muted and no electron beam 12 flows.

Description

【発明の詳細な説明】 (産業上の利用分野) この発明は、テレビジョン受信機等の陰極線管(以下、
rcRTJという)装置に関する。
DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to cathode ray tubes (hereinafter referred to as
rcRTJ) device.

(従来の技術〕 第2図は従来のCRT装置を示す回路図である。(Conventional technology) FIG. 2 is a circuit diagram showing a conventional CRT device.

図において、 (7)は垂直偏向カップリングコンデン
サ、 (8)はフィードバック抵抗、 (9)は電子銃
、(lO)は偏向ヨーク、(11)はCRT、(12)
は電子ビーム、 (13a) 、 (13b)は垂直出
力トランジスタ、(14)はCRTのアノードである。
In the figure, (7) is a vertical deflection coupling capacitor, (8) is a feedback resistor, (9) is an electron gun, (lO) is a deflection yoke, (11) is a CRT, (12)
is an electron beam, (13a) and (13b) are vertical output transistors, and (14) is an anode of a CRT.

つぎに、動作について説明する。Next, the operation will be explained.

CRT (11)のアノード(14)には、直流高電圧
が印加されており、電子ビーム(12)を発生させて蛍
光体に当てる原動力となっている。偏向ヨーク(lO)
の垂直偏向コイルには、第3図(a)に示すのこぎり被
電流が垂直出力トランジスタ(13a)。
A high DC voltage is applied to the anode (14) of the CRT (11), which serves as the driving force for generating an electron beam (12) and hitting the phosphor. Deflection yoke (lO)
The vertical deflection coil receives a sawtooth current as shown in FIG. 3(a) through a vertical output transistor (13a).

(13b)から通電されて垂直偏向磁界を発生し、電子
ビーム(12)をCRT (11)の上から下へ走査さ
せる。
(13b) generates a vertical deflection magnetic field and causes the electron beam (12) to scan from the top to the bottom of the CRT (11).

他方、偏向ヨーク(10)の水平偏向コイルには、図示
していない水平偏向回路から水平偏向電流が通電されて
水平偏向磁界を発生し、CRT (11)の蛍光面にラ
スタが形成される。垂直のこぎり波1流の+側の電流は
、垂直出力トランジスタ(13a)がONになったとき
に流れて垂直カップリングコンデンサ(7)を充電し、
−側の電流は垂直出力トランジスタ(13b)がONに
なったときカップリングコンデンサ(7)から流れ、垂
直帰線時間には垂直偏向コイルにパルス電圧が加えられ
、−側から+側へと電流が変化して、第3図(a)に示
すのこぎり被電流が形成されている。
On the other hand, a horizontal deflection current is applied to the horizontal deflection coil of the deflection yoke (10) from a horizontal deflection circuit (not shown) to generate a horizontal deflection magnetic field, and a raster is formed on the fluorescent screen of the CRT (11). The positive current of the first vertical sawtooth wave flows when the vertical output transistor (13a) is turned on and charges the vertical coupling capacitor (7).
The - side current flows from the coupling capacitor (7) when the vertical output transistor (13b) is turned on, and a pulse voltage is applied to the vertical deflection coil during the vertical retrace time, causing the current to flow from the - side to the + side. changes, forming the sawtooth current shown in FIG. 3(a).

〔発明が解決しようとする課題) 従来のCRT装置は、垂直カップリングコンデンサ(7
)が短絡したり、容量ぬけなどが生じると、垂直偏向電
流が第3図(b)に示すような波形の直流電流となるた
め、電子ビーム(12)が第2図に示すようにCRT 
(11)の上部に集中し、CRT (11)を損傷する
という問題点があった。
[Problem to be solved by the invention] Conventional CRT devices have vertical coupling capacitors (7
) is short-circuited or the capacitance is lost, the vertical deflection current becomes a direct current with the waveform shown in Figure 3(b), and the electron beam (12) is connected to the CRT as shown in Figure 2.
There was a problem in that it concentrated on the upper part of the CRT (11) and damaged the CRT (11).

この発明は上記のような問題点を解消するためになされ
たもので、垂直偏向電流が直流電流となったときでもC
RTを損傷することのないCRT装置を得ることを目的
とする。
This invention was made to solve the above problems, and even when the vertical deflection current becomes a direct current, the C
An object of the present invention is to obtain a CRT device that does not damage the RT.

〔課題を解決するための手段〕[Means to solve the problem]

この発明に係るCRT装置は、垂直偏向電圧を検出し、
この検出電圧が所定値より低いとき、CRTの電子ビー
ムを発生させないように制御するようにしたものである
A CRT device according to the present invention detects a vertical deflection voltage,
When this detection voltage is lower than a predetermined value, the CRT is controlled so as not to generate an electron beam.

〔作用〕[Effect]

この発明における垂直偏向電圧検出手段は、垂直偏向電
流が正常なのこぎり波であるとき高電圧を検出し、異常
な直流波になったとき低電圧を検出する。CRTの電子
ビーム制御手段は、検出電圧が所定値より高いとき作動
せず、所定値より低くなったとき電子ビームが発生しな
いようにCRTを制御する。
The vertical deflection voltage detection means in this invention detects a high voltage when the vertical deflection current is a normal sawtooth wave, and detects a low voltage when the vertical deflection current is an abnormal DC wave. The electron beam control means of the CRT does not operate when the detected voltage is higher than a predetermined value, and controls the CRT so that no electron beam is generated when the detected voltage is lower than a predetermined value.

(発明の実施例〕 以下、この発明の実施例について説明する。(Embodiments of the invention) Examples of the present invention will be described below.

第1図において、 (6)は抵抗で、その一端は垂直カ
ップリングコンデンサ(7) の+側に接続され、他端
はコンデンサ(5)の+側に接続されて積分回路を構成
している。(4)はツェナーダイオードで、アノードが
コンデンサ(5)の+側に接続され、カソードはダイオ
ード(3)のカソードに接続され、そのダイオード(3
)のアノードはトランジスタ(2)のベースに接続され
、トランジスタ(2)のエミッタは電源に接続され、コ
レクタは映像ミュート回路(15)に接続されている。
In Figure 1, (6) is a resistor, one end of which is connected to the + side of vertical coupling capacitor (7), and the other end connected to the + side of capacitor (5), forming an integrating circuit. . (4) is a Zener diode, the anode of which is connected to the + side of the capacitor (5), the cathode of which is connected to the cathode of the diode (3);
) is connected to the base of the transistor (2), the emitter of the transistor (2) is connected to the power supply, and the collector is connected to the video mute circuit (15).

映像ミュート回路(15)は、トランジスタ(2)から
信号が入力されたとき、CRT (11)の電子銃(9
)に入力される映像信号をブランクレベルに保持して電
子ビーム(12)が発生しないようにCRT (11)
を制御する。
The video mute circuit (15) mutes the electron gun (9) of the CRT (11) when a signal is input from the transistor (2).
) to keep the video signal input to the CRT (11) at a blank level so that no electron beam (12) is generated.
control.

つぎに、動作を説明する。Next, the operation will be explained.

いま、垂直カップリングコンデンサ(7)が短絡したと
すると、垂直偏向コイルには、第3図(b)に示すよう
な波形の直流電流が流れ、電子ビーム(12)はCRT
 (II)の上部に集中して流れることとなる。フィー
ドバック抵抗(8)のインピーダンスを1.5Ω、垂直
偏向コイルの直流抵抗を6Ωとすると、垂直出力トラン
ジスタ(13a)から流れ込む直流電流量はフィードバ
ック抵抗(8)のところで約3v程度となり、ツェナー
ダイオード(4)のカソードとアノードの電位差は7v
以上になる。
Now, if the vertical coupling capacitor (7) is short-circuited, a DC current with a waveform as shown in Figure 3(b) flows through the vertical deflection coil, and the electron beam (12) is connected to the CRT.
The flow will be concentrated in the upper part of (II). Assuming that the impedance of the feedback resistor (8) is 1.5Ω and the DC resistance of the vertical deflection coil is 6Ω, the amount of DC current flowing from the vertical output transistor (13a) will be approximately 3V at the feedback resistor (8), ) The potential difference between the cathode and anode is 7V.
That's all.

この実施例では、ツェナー電圧が7vのツェナーダイオ
ードを用いているので、カソードからアノードへ電流が
流れ込み、トランジスタ(2)がONになって映像ミュ
ート回路(15)へミュート信号が送出され、映像信号
がミュートされて電子ビーム(12)が流れなくなる。
In this embodiment, a Zener diode with a Zener voltage of 7V is used, so current flows from the cathode to the anode, turning on the transistor (2) and sending a mute signal to the video mute circuit (15), which mutes the video signal. is muted and the electron beam (12) no longer flows.

このため、CRT (11)が損傷されることはない。Therefore, the CRT (11) will not be damaged.

なお、電源のON、OFF時にも゛同様に作動してCR
T (11)を保護する作用を有している。
Furthermore, CR operates in the same way when the power is turned on and off.
It has the effect of protecting T (11).

また、ダイオード(3)は、垂直偏向電流の波形が正常
な場合には、トランジスタ(2)が作動するのを阻止す
る作用を有している。
Further, the diode (3) has a function of preventing the transistor (2) from operating when the waveform of the vertical deflection current is normal.

なお、上記実施例では、電子銃に印加される映像信号に
ミュートを掛けて電子ビームを消滅させてCRTを保護
したが、水平発振回路の動作を止めて直流高電圧の発生
を止めるようにしてもよい。
In the above embodiment, the video signal applied to the electron gun is muted to extinguish the electron beam to protect the CRT, but the operation of the horizontal oscillation circuit is stopped to stop the generation of DC high voltage. Good too.

〔発明の効果〕〔Effect of the invention〕

以上のようにこの発明によれば、垂直偏向電圧を検出す
る手段と、この検出電圧が所定値より低くなったときC
RTの電子ビームを消滅させる手段とを備えたものであ
るから、垂直カップリングコンデンサの短絡等によって
垂直偏向電流が直流電流となったときは電子ビームを消
滅させ、CRTを損傷させないCRT装置が得られる効
果がある。
As described above, according to the present invention, there is provided means for detecting a vertical deflection voltage, and when the detected voltage becomes lower than a predetermined value, the
Since the device is equipped with a means for extinguishing the electron beam of the RT, when the vertical deflection current becomes a direct current due to a short circuit in the vertical coupling capacitor, etc., the electron beam is extinguished and a CRT device that does not damage the CRT can be obtained. It has the effect of

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

第1図はこの発明の一実施例のブロック回路図、第2図
は従来のCRT装置のブロック回路図、第3図は垂直偏
向電流波形図である。 (2)・・・トランジスタ、 (3)・・・ダイオード
、 (4)・・・ツェナーダイオード、 (7)・・・
カップリングコンデンサ、 (8)・・・フィードバッ
ク抵抗、(9)・・・電子銃、(10)・・・偏向ヨー
ク、(11)・・・CRT、(12)・・・電子ビーム
、(13a) 、 (13b)・・・垂直出力トランジ
スタ、(15)・・・映像ミュート回路、(16)・・
・積分回路。 なお、各図中、同一符号はそれぞれ同一 または相当部
分を示す。
FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a block circuit diagram of a conventional CRT device, and FIG. 3 is a vertical deflection current waveform diagram. (2)...Transistor, (3)...Diode, (4)...Zener diode, (7)...
Coupling capacitor, (8)... Feedback resistor, (9)... Electron gun, (10)... Deflection yoke, (11)... CRT, (12)... Electron beam, (13a ), (13b)...Vertical output transistor, (15)...Video mute circuit, (16)...
・Integrator circuit. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

【特許請求の範囲】[Claims] (1)電子銃から発射された電子ビームを蛍光面に当て
て発光させる陰極線管と、上記電子ビームを偏向させる
偏向ヨークと、この偏向ヨークの垂直偏向コイルに垂直
偏向電流を給電する垂直偏向回路と、上記垂直偏向コイ
ルに印加される垂直偏向電圧を検出する手段と、この検
出電圧が所定の電圧値より低いとき上記電子ビームが発
生しないように制御する手段とを備えた陰極線管装置。
(1) A cathode ray tube that emits electron beams emitted from an electron gun by hitting a phosphor screen, a deflection yoke that deflects the electron beams, and a vertical deflection circuit that supplies vertical deflection current to the vertical deflection coil of this deflection yoke. A cathode ray tube device comprising: means for detecting a vertical deflection voltage applied to the vertical deflection coil; and means for controlling the electron beam so as not to be generated when the detected voltage is lower than a predetermined voltage value.
JP31376889A 1989-12-01 1989-12-01 Cathode ray tube device Pending JPH03173271A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP31376889A JPH03173271A (en) 1989-12-01 1989-12-01 Cathode ray tube device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP31376889A JPH03173271A (en) 1989-12-01 1989-12-01 Cathode ray tube device

Publications (1)

Publication Number Publication Date
JPH03173271A true JPH03173271A (en) 1991-07-26

Family

ID=18045292

Family Applications (1)

Application Number Title Priority Date Filing Date
JP31376889A Pending JPH03173271A (en) 1989-12-01 1989-12-01 Cathode ray tube device

Country Status (1)

Country Link
JP (1) JPH03173271A (en)

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