JPS636777Y2 - - Google Patents
Info
- Publication number
- JPS636777Y2 JPS636777Y2 JP3134381U JP3134381U JPS636777Y2 JP S636777 Y2 JPS636777 Y2 JP S636777Y2 JP 3134381 U JP3134381 U JP 3134381U JP 3134381 U JP3134381 U JP 3134381U JP S636777 Y2 JPS636777 Y2 JP S636777Y2
- Authority
- JP
- Japan
- Prior art keywords
- video signal
- ray tube
- video
- cathode ray
- amplification stage
- 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
Links
- 230000003321 amplification Effects 0.000 claims description 7
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 7
- 230000000087 stabilizing effect Effects 0.000 claims description 4
- 230000001419 dependent effect Effects 0.000 claims description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
Landscapes
- Transforming Electric Information Into Light Information (AREA)
- Picture Signal Circuits (AREA)
Description
【考案の詳細な説明】
本考案はキヤラクタデイスプレイにおける映像
増幅段とブラウン管の映像信号印加用電極、例え
ばカソードとの結合に係り、特にアンダースキヤ
ン時のバツクラスタの輝度の映像信号に対する変
動を防止したバツクラスタの安定化回路に関す
る。[Detailed description of the invention] The present invention relates to the coupling between the video amplification stage and the video signal application electrode of a cathode ray tube, such as the cathode, in a character display, and particularly prevents variations in the brightness of the cross cluster with respect to the video signal during underscanning. This article relates to a stabilizing circuit for a cross cluster.
一般にブラウン管上に種々の文字、図面等を表
示するキヤラクタデイスプレイは、先ずその回路
構成として、映像出力段の負荷にブラウン管のカ
ソードを直流結合すると共に、そのグリツドを所
定電位に保つために可変抵抗器により固定バイア
スを与えていた。 In general, a character display that displays various characters, drawings, etc. on a cathode ray tube has a circuit configuration in which the cathode of the cathode is directly coupled to the load of the video output stage, and a variable resistor is used to maintain the grid at a predetermined potential. A fixed bias was applied depending on the instrument.
このとき前記映像出力段の入力側に加わる映像
信号により、即ち波形の相違によつて前記ブラウ
ン管のビーム電流に対応してバツクラスタの輝度
（明るさ）が変化してしまい、例えば１文字を表
示する場合と多数の文字を表示する場合とはかな
りバツクラスタの輝度が変化し、キヤラクタデイ
スプレイとしては大きな支障となつていた。 At this time, due to the video signal applied to the input side of the video output stage, that is, due to the difference in waveform, the luminance (brightness) of the cross cluster changes in accordance with the beam current of the cathode ray tube, and for example, one character is displayed. The brightness of the cross cluster changes considerably between when displaying a large number of characters and when displaying a large number of characters, which is a major problem when used as a character display.
これはキヤラクタデイスプレイが、アンダース
キヤン即ちブラウン管の画面上で縦横の各々に於
いて、文字、図形等の表示部分は全画面の高さ及
び幅を小さく設定してあり、斯る文字、図形等の
表示部分以外の部分に相当する非表示部分がバツ
クラスタとして、一定の明るさにならなければ、
文字、図面等の表示部分が見難い欠点が生じる。 This is because the character display is underscanned, which means that the height and width of the entire screen for displaying characters, figures, etc. is set to be small in both the vertical and horizontal directions on the screen of the cathode ray tube. If the non-display part corresponding to the part other than the display part becomes a cross cluster and does not have a constant brightness,
This results in the disadvantage that displayed parts such as characters and drawings are difficult to see.
そこで本考案は前記欠点を除去した新規なバツ
クラスタ安定化回路を提供するもので、以下図面
に従つて説明する。 Therefore, the present invention provides a new cross-cluster stabilizing circuit which eliminates the above-mentioned drawbacks, and will be described below with reference to the drawings.
第１図は本考案のバツクラスタ安定化回路、第
２図イ，ロ及び第３図は同回路の説明波形図を示
す。第１図において１は入力端子、２は映像出力
トランジスタ３を有する映像増幅段、４は負荷抵
抗、５，６は分圧抵抗、７，８及び９は直流電圧
端子、１０は電圧依存性可変抵抗素子として設け
たバリスタ、１１，１２はデカツプリングコンデ
ンサ、１３はブラウン管、１４は輝度調整用の可
変抵抗器、１５，１６は逆流阻止用ダイオード、
１７はバイパス用コンデンサ、１８，１９はバイ
アス用抵抗を示す。 FIG. 1 shows a cross-cluster stabilizing circuit of the present invention, and FIGS. 2A, 2B, and 3 show explanatory waveform diagrams of the same circuit. In Fig. 1, 1 is an input terminal, 2 is a video amplification stage having a video output transistor 3, 4 is a load resistor, 5, 6 are voltage dividing resistors, 7, 8, and 9 are DC voltage terminals, and 10 is a voltage-dependent variable A varistor was provided as a resistance element, 11 and 12 are decoupling capacitors, 13 is a cathode ray tube, 14 is a variable resistor for brightness adjustment, 15 and 16 are backflow blocking diodes,
17 is a bypass capacitor, and 18 and 19 are bias resistors.
いま仮に入力端子１に映像信号v1が印加された
とき（例えば文字「Ｈ」に対応する映像信号とす
る）映像出力トランジスタ３に流れる電流は比較
的小さいので、Ｂ点即ちブラウン管１３のカソー
ド電位は分圧点Ｃの電位にほぼ等しい。この状態
にて前述の可変抵抗器１４をバツクラスタが消え
た状態に設定されているとすると、このときのブ
ラウン管１３のバイアスをEc1とする。 Now, when a video signal v 1 is applied to the input terminal 1 (for example, a video signal corresponding to the letter "H"), the current flowing through the video output transistor 3 is relatively small, so the voltage at point B, that is, the cathode potential of the cathode ray tube 13 is approximately equal to the potential at the voltage dividing point C. In this state, if the variable resistor 14 is set so that the cross cluster disappears, the bias of the cathode ray tube 13 at this time is set to E c1 .
次に映像信号v2が前記入力端子１に印加される
と（T2＞T1）、前記映像出力トランジスタ３に
は、前述の場合に比し大きな電流が流れて、ブラ
ウン管１３のカソード電位は負荷抵抗４における
電圧降下が大きいことから、前述の場合に比して
下がり、従つてブラウン管１３に対するバイアス
は浅くなろうとする。このときのバイアスをEc2
とすると、前記バイアスEc1及びEc2に対応するブ
ラウン管１３のカソード電流Ikは第３図において
Ik1及びIk2にて示す如く、Ik1＜Ik2となり、その
変動分ΔIkが生じる。前記変動分ΔIkにより、映
像信号v2の場合のバツクラスタはv1の場合に比し
て明るくなつてしまい、画面上映像信号に対応す
る文字又は図形等が見難くなる。 Next, when the video signal v 2 is applied to the input terminal 1 (T 2 > T 1 ), a larger current flows through the video output transistor 3 than in the above case, and the cathode potential of the cathode ray tube 13 becomes Since the voltage drop across the load resistor 4 is large, it is lower than in the case described above, and therefore the bias to the cathode ray tube 13 tends to become shallower. The bias at this time is E c2
Then, the cathode current I k of the cathode ray tube 13 corresponding to the biases E c1 and E c2 is as shown in FIG.
As shown by Ik 1 and Ik 2 , Ik 1 <Ik 2 , and the variation ΔIk occurs. Due to the variation ΔIk, the cross cluster in the case of the video signal v2 becomes brighter than in the case of v1 , making it difficult to see characters, figures, etc. corresponding to the video signal on the screen.
ところが前記映像信号v2が入力端子１に印加さ
れ、負荷抵抗４による電圧降下が大になつたと
き、バリスタ１０に加わる電圧が増大することに
なるので、その内部抵抗は減少し、Ｃ点の電位を
下げるように働き、これによつてブラウン管１３
のカソード電位は前記映像信号v1の場合と同じ値
に向つて上昇する。 However, when the video signal v 2 is applied to the input terminal 1 and the voltage drop due to the load resistor 4 becomes large, the voltage applied to the varistor 10 increases, its internal resistance decreases, and the voltage at point C increases. It works to lower the potential, thereby causing the cathode ray tube 13
The cathode potential of increases towards the same value as in the case of the video signal v1 .
更にこのとき抵抗１８を介して点Ｄの電位は減
少し、これに伴いブラウン管１３のバイアスは
Ec2からEc1に等しくなつて、カソード電流Ikは
Ik2＝Ik1になり、その結果バツクラスタの輝度は
一定に保たれることになる。 Furthermore, at this time, the potential at point D decreases via the resistor 18, and the bias of the cathode ray tube 13 accordingly decreases.
E c2 becomes equal to E c1 , and the cathode current Ik is
Ik 2 =Ik 1 , and as a result, the brightness of the cross cluster is kept constant.
ここで点Ｄにおける正の電位及びインピーダン
スの値は点Ｃより高いものとする。 Here, it is assumed that the positive potential and impedance value at point D are higher than at point C.
以上の通り本考案によれば、映像増幅段の負荷
抵抗に接続されたバリスタ等の電圧依存性可変抵
抗素子により、映像信号の内容によつてブラウン
管のカソード及びグリツドの直流電位が変化する
のを防止でき、従つて該ブラウン管のバイアスを
一定に保ち得るので、バツクラスタの安定化が可
能となり、本考案回路はキヤラクタデイスプレイ
に用いれば、極めて有用である。 As described above, according to the present invention, a voltage-dependent variable resistance element such as a varistor connected to the load resistor of the video amplification stage prevents changes in the DC potential of the cathode and grid of the cathode ray tube depending on the content of the video signal. Since the bias of the cathode ray tube can be kept constant, it is possible to stabilize the cross cluster, and the circuit of the present invention is extremely useful when used in a character display.
なお映像信号の極性に応じてブラウン管のグリ
ツドに該映像信号を印加しても前述のカソード印
加の場合と同様の効果が得られる。 Note that even if the video signal is applied to the grid of the cathode ray tube depending on the polarity of the video signal, the same effect as in the case of cathode application described above can be obtained.
第１図は本考案のバツクラスタの安定化回路、
第２図イ，ロ及び第３図は本考案の説明波形図を
示す。
主な図番の説明、２……映像増幅段、３……映
像出力トランジスタ、４……負荷抵抗、１０……
バリスタ、１３……ブラウン管、１４……可変抵
抗器、１８，１９……バイアス抵抗。
Figure 1 shows the cross cluster stabilization circuit of the present invention.
FIGS. 2A and 2B and FIG. 3 show explanatory waveform diagrams of the present invention. Explanation of main drawing numbers, 2 ...Video amplification stage, 3...Video output transistor, 4...Load resistor, 10...
Varistor, 13... Braun tube, 14... Variable resistor, 18, 19... Bias resistor.
Claims (1)
加用の電極を直流結合し、所定の文字又は図形を
表示するキヤラクタデイスプレイにおいて、前記
映像増幅段に接続された負荷抵抗とアース間に電
圧依存性可変抵抗素子を接続すると共に該電圧依
存性可変抵抗素子の一端を抵抗を介して輝度調整
用の可変抵抗器の一端に接続し、前記映像増幅段
の入力端子に印加される映像信号に対し、バツク
ラスタの輝度を一定に保つことを特徴としたバツ
クラスタの安定化回路。 In a character display in which a cathode ray tube's video signal application electrode is DC-coupled to the output side of the video amplification stage and a predetermined character or figure is displayed, there is a voltage dependence between the load resistor connected to the video amplification stage and the ground. A variable resistance element is connected, and one end of the voltage-dependent variable resistance element is connected to one end of a brightness adjustment variable resistor via a resistor, and for a video signal applied to the input terminal of the video amplification stage, A stabilizing circuit for the cross cluster, which is characterized by keeping the brightness of the cross cluster constant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3134381U JPS636777Y2 (en) | 1981-03-05 | 1981-03-05 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3134381U JPS636777Y2 (en) | 1981-03-05 | 1981-03-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57146188U JPS57146188U (en) | 1982-09-14 |
| JPS636777Y2 true JPS636777Y2 (en) | 1988-02-26 |
Family
ID=29828776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3134381U Expired JPS636777Y2 (en) | 1981-03-05 | 1981-03-05 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS636777Y2 (en) |
-
1981
- 1981-03-05 JP JP3134381U patent/JPS636777Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57146188U (en) | 1982-09-14 |
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