JPS5887992A - Color temperature correction circuit - Google Patents
Color temperature correction circuitInfo
- Publication number
- JPS5887992A JPS5887992A JP56186012A JP18601281A JPS5887992A JP S5887992 A JPS5887992 A JP S5887992A JP 56186012 A JP56186012 A JP 56186012A JP 18601281 A JP18601281 A JP 18601281A JP S5887992 A JPS5887992 A JP S5887992A
- Authority
- JP
- Japan
- Prior art keywords
- blue
- resistor
- detection circuit
- video signal
- variable resister
- 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
Links
- 238000001514 detection method Methods 0.000 claims abstract description 10
- 241001057181 Orcus Species 0.000 claims description 7
- 238000004904 shortening Methods 0.000 abstract 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/64—Circuits for processing colour signals
- H04N9/73—Colour balance circuits, e.g. white balance circuits or colour temperature control
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Video Image Reproduction Devices For Color Tv Systems (AREA)
- Processing Of Color Television Signals (AREA)
Abstract
Description
【発明の詳細な説明】 この発明は投写型テレビジョン受信機などにお邑 ける温度補正回路に関するものである。[Detailed description of the invention] This invention is useful for projection television receivers, etc. The present invention relates to a temperature correction circuit that can be used.
△
投写型テレビジョン受信機においては、輝度を上げるた
めに、陰極線管Ｃ以下ＯＲＴと略称する）の螢光面上へ
のビーム電流を大きくする必要がある。しかしながら、
この場合、青色螢光体は飽和しやすいために一赤、緑、
青の６色を合成したスクリーン上で白色部が黄色味を帯
びるという欠点があった。このため、種々提案されてい
る色温度補正回路を設けても、逆効果となるおそれがあ
った。Δ In a projection television receiver, in order to increase brightness, it is necessary to increase the beam current onto the fluorescent surface of a cathode ray tube (hereinafter abbreviated as ORT). however,
In this case, the blue phosphor is easily saturated, so the red, green,
There was a drawback in that white areas appeared yellowish on a screen that combined six colors of blue. For this reason, even if various proposed color temperature correction circuits are provided, there is a risk that the opposite effect will occur.
この発明はこのような従来の欠点全除去するものであっ
て、ビデオ信号の白ピークを検出し、これにもとづいて
青色の７オーカス電圧を規定値より若干ずらすことによ
り、青色では走査線部に電流が集中しないようにし、こ
れによって青色の飽和によυ白色部が黄色味を帯びるの
を防止した色温度補正回路を提供することを目的として
いる。This invention completely eliminates these conventional drawbacks by detecting the white peak of the video signal and, based on this, slightly shifting the blue 7 orcus voltage from the specified value. It is an object of the present invention to provide a color temperature correction circuit that prevents current concentration and thereby prevents white parts from becoming yellowish due to blue saturation.
以下、この発明の実施例を第１図にしたがって説明する
。図において、（１）はビデオ信号を増幅するビデオ増
１−器、（２Ｒ）、（２Ｇ）、（２Ｂ）は終段増幅器、
（３Ｒ）、（３Ｇ）、（３ｎ）はそれぞれ赤、緑、青の
各色に対応するＯ ＲＴ 、 （５Ｒ）、（５Ｇ）、（
５Ｂ）は赤、緑、青のそれぞれのフォーカス電圧を調整
する調整ボリウム、Ｖは高１１Ｌｌ：Ｅ印加端子である
。Embodiments of the present invention will be described below with reference to FIG. In the figure, (1) is a video amplifier that amplifies the video signal, (2R), (2G), and (2B) are final stage amplifiers,
(3R), (3G), and (3n) are O RT , (5R), (5G), ( corresponding to each color of red, green, and blue, respectively.
5B) is an adjustment volume for adjusting each focus voltage for red, green, and blue, and V is a high 11Ll:E application terminal.
（４）は一対のトランジスタ褥υ、（ロ）と抵抗（匈〜
（９）からなる白ピークの検出回路であって、この検出
回路（４）にはビデオ増幅′ａ（１）の増幅出力が入力
されるとともに、検出回路（４）の出力は次段のトラン
ジスタ１６１のベースへ与えられる。トランジスターの
コレクタ・エミッタ間には抵抗（６９）が並列に接続さ
れており、この抵抗−は青色の７オーカス電圧調整ボリ
ウム（５Ｂ）と直列に接続されている。トランジスター
と抵抗−とによって制御回路（６）が構成される。なお
、赤と緑の調整ボリウム（５Ｒ）、（５Ｇ）の一端は青
色の調整ボリウム（５Ｂ）の一端とともに高電圧印加端
子Ｖへ共通に接続されているが、その他端は青色とは異
なり、直＋１１接地されている。(4) is a pair of transistors υ, (b) and resistors (匈~
(9), the amplified output of the video amplifier 'a (1) is input to this detection circuit (4), and the output of the detection circuit (4) is transmitted to the transistor of the next stage. 161 is given to the base. A resistor (69) is connected in parallel between the collector and emitter of the transistor, and this resistor is connected in series with a blue 7-orcus voltage adjustment volume (5B). A control circuit (6) is constituted by a transistor and a resistor. Note that one end of the red and green adjustment volume (5R), (5G) is commonly connected to the high voltage application terminal V together with one end of the blue adjustment volume (5B), but the other end is different from the blue one. Direct+11 grounded.
以上の構成において、ビデオ信号のレベルが吐いときに
は、検出回路（４）の出力はｒＨＪとなってトランジス
ターがＯＮとなり、抵抗−を短絡するので、ボリウム（
５Ｂ）の一端はボリウム（５Ｒ）、（５Ｇ）と同様に接
地される。この状態で７オーカスが最適になるようボリ
ウム（５Ｒ） 、（５Ｇ）、（５Ｂ）を調整する。In the above configuration, when the level of the video signal is high, the output of the detection circuit (4) becomes rHJ, the transistor turns on, and the resistor - is short-circuited.
One end of 5B) is grounded like the volumes (5R) and (5G). In this state, adjust the volumes (5R), (5G), and (5B) so that 7 orcuses are optimal.
つぎに高振幅の白レベル信号が検出回路（４）で検出さ
れると、検出回路（４）の出力は「Ｌ」となってトラン
ジスターが０ＩＦＦとなり、抵抗■の短絡を解く。Next, when a high amplitude white level signal is detected by the detection circuit (4), the output of the detection circuit (4) becomes "L", the transistor becomes 0IFF, and the short circuit of the resistor (2) is released.
そうすると、青色の調整ボリウム（５Ｂ）に直列に抵抗
−が接続されることになるので、青色の７オーカス電圧
は調整値よシ若干ずれる。その結果、青の螢光体上では
ビームが走査線に対応して集中することがなく、ビーム
の飽和が避けられるので、白ピーク時においても青色の
欠如した、つまり黄色味を帯びた色が生じるのを防止す
ることができる。なお、青色は赤や緑に比べて７オーカ
スへの影響が少ないので、７オーカスをあまり犠牲にし
なくてすむ。またーこの発明は＃電７オーカス、磁界フ
ォーカスを問わず通用可能であることはいうまでもない
。In this case, since a resistor is connected in series to the blue adjustment volume (5B), the blue 7 orcus voltage deviates slightly from the adjustment value. As a result, the beam does not concentrate on the blue phosphor corresponding to the scanning line, and saturation of the beam is avoided, so even at the white peak, the color lacks blue, that is, has a yellowish tinge. This can be prevented from occurring. Note that blue has less influence on 7 orcus than red or green, so there is no need to sacrifice 7 orcus too much. Furthermore, it goes without saying that this invention is applicable regardless of #electronic7orcus or magnetic field focus.
以上述べたように、この発明によれば、ビデオ信号の白
ピークを検出して青色の７オーカス電圧を規定値よりず
らすことによシ、青色での飽和を避けるようにしたので
、画面上の白文字等が黄色味を帯びるのを有効に防止す
ることができる。As described above, according to the present invention, saturation in the blue color is avoided by detecting the white peak of the video signal and shifting the blue 7 orcus voltage from the specified value. It is possible to effectively prevent white characters etc. from becoming yellowish.
図面はこの発明の色濡変補正回路の実施例を示す回路図
である。
（１）・・・ビデオ増＋１緒、（３Ｒ） 、 （３Ｇ）
、 （３Ｂ）・・・ＯＲＴ、（４）・・・検出回路、（
５Ｒ） ＋ （５Ｇ ） 、 （５Ｂ ）・・・調整ボ
リウム、（６）・・・制御回路。
代理人葛野信−（外１名）The drawing is a circuit diagram showing an embodiment of the color variation correction circuit of the present invention. (1)...Video increase + 1, (3R), (3G)
, (3B)...ORT, (4)...detection circuit, (
5R) + (5G), (5B)...adjustment volume, (6)...control circuit. Agent Shin Kuzuno (1 other person)
Claims (1)
オ増幅器の出力により駆動される赤、緑、青の各色に対
応する陰極１ｌｌＩ管と、赤、緑、青のそれぞれの７オ
ーカス′亀ＥＥ′ｔｔ調整する調整回路と、上記ビデオ
信号の白ピークを検出する検出回路と、この検出回路が
白ピークを検出したときに青色の７オーカス亀田を調整
値よりずらすように制御する制御回路とを備えたことを
特徴とする色温度補正回路。(1) A video amplifier that amplifies the video signal, 111 cathode tubes corresponding to each color of red, green, and blue driven by the output of this video amplifier, and 7 orifices each of red, green, and blue 'Turtle EE' tt adjustment, a detection circuit that detects the white peak of the video signal, and a control circuit that controls the blue 7 orcus Kameda to be shifted from the adjustment value when the detection circuit detects the white peak. A color temperature correction circuit characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56186012A JPS5887992A (en) | 1981-11-18 | 1981-11-18 | Color temperature correction circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56186012A JPS5887992A (en) | 1981-11-18 | 1981-11-18 | Color temperature correction circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5887992A true JPS5887992A (en) | 1983-05-25 |
Family
ID=16180828
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56186012A Pending JPS5887992A (en) | 1981-11-18 | 1981-11-18 | Color temperature correction circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5887992A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4982276A (en) * | 1989-01-19 | 1991-01-01 | Matsushita Electric Industrial Co., Ltd. | Focussing adjustment changeover circuit for projection TV receiver |
| JPH08265793A (en) * | 1995-03-27 | 1996-10-11 | Nec Corp | White balance control circuit and control method |
| EP1289315A2 (en) | 2001-07-27 | 2003-03-05 | Hitachi, Ltd. | Video display device and color temperature correction method for the same |
-
1981
- 1981-11-18 JP JP56186012A patent/JPS5887992A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4982276A (en) * | 1989-01-19 | 1991-01-01 | Matsushita Electric Industrial Co., Ltd. | Focussing adjustment changeover circuit for projection TV receiver |
| JPH08265793A (en) * | 1995-03-27 | 1996-10-11 | Nec Corp | White balance control circuit and control method |
| EP1289315A2 (en) | 2001-07-27 | 2003-03-05 | Hitachi, Ltd. | Video display device and color temperature correction method for the same |
| EP1289315A3 (en) * | 2001-07-27 | 2005-04-27 | Hitachi, Ltd. | Video display device and color temperature correction method for the same |
| EP2148516A1 (en) * | 2001-07-27 | 2010-01-27 | Hitachi Ltd. | Video display device and color temperature correction method for the same |
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