JPH0337258B2 - - Google Patents
Info
- Publication number
- JPH0337258B2 JPH0337258B2 JP60109858A JP10985885A JPH0337258B2 JP H0337258 B2 JPH0337258 B2 JP H0337258B2 JP 60109858 A JP60109858 A JP 60109858A JP 10985885 A JP10985885 A JP 10985885A JP H0337258 B2 JPH0337258 B2 JP H0337258B2
- Authority
- JP
- Japan
- Prior art keywords
- black
- voltage
- image pickup
- level
- output
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/10—Cameras or camera modules comprising electronic image sensors; Control thereof for generating image signals from different wavelengths
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Color Television Image Signal Generators (AREA)
- Processing Of Color Television Signals (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明はテレビジヨンカメラの自動黒レベル設
定装置に係り、例えば赤（Ｒ）、緑（Ｇ）、青
（Ｂ）の撮像管を用いたテレビジヨンカメラにお
いて、自動的に黒レベルを設定する装置に関す
る。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic black level setting device for a television camera, for example, a television camera using red (R), green (G), and blue (B) image pickup tubes. The present invention relates to a device for automatically setting a black level in a camera.
従来の技術
第２図は従来の自動黒レベル設定装置の一例の
ブロツク系統図を示す。Ｂ、Ｇ、Ｒの各撮像管か
らの出力はアンプ１B，１G，１Rにて増幅された
後黒固定回路２B，２G，２Rにて所定クランプレ
ベルを以て黒レベルをクランプされ、黒検出回路
３B，３G，３Rにて黒レベル平均電圧を取出され、
比較回路４1，４2に供給される。2. Prior Art FIG. 2 shows a block diagram of an example of a conventional automatic black level setting device. The outputs from the B, G, and R image pickup tubes are amplified by amplifiers 1B , 1G , and 1R , and then the black level is clamped at a predetermined clamp level by black fixing circuits 2B , 2G , and 2R . , the black level average voltage is extracted by the black detection circuits 3 B , 3 G , and 3 R ,
It is supplied to comparison circuits 4 1 and 4 2 .
比較回路４1においてＢの黒レベル平均電圧と
Ｇの黒レベル平均電圧とが比較されて比較誤差電
圧とされる一方、比較回路４2にてＲの黒レベル
平均電圧とＧの黒レベル平均電圧とが比較されて
比較誤差電圧とされ、夫々ADコンバータ５1，５
２にてAD変換され、夫々アンプ６B，６Rに供給さ
れてそのゲインを可変する。これにより、Ｂの黒
固定回路２B及びＲの黒固定回路２Rの夫々のクラ
ンプレベルはＧの黒固定回路２Gの出力を基準に
可変設定される。 In the comparison circuit 41 , the average black level voltage of B and the average black level voltage of G are compared and used as a comparison error voltage, while in the comparison circuit 42 , the average black level voltage of R and the average black level voltage of G are compared. are compared and set as a comparison error voltage, and the AD converters 5 1 and 5 are respectively
2 , the signals are AD-converted and supplied to amplifiers 6 B and 6 R, respectively, to vary their gains. As a result, the respective clamp levels of the B black fixing circuit 2 B and the R black fixing circuit 2 R are variably set based on the output of the G black fixing circuit 2 G.
発明が解決しようとする問題点
一般に、テレビジヨンカメラは焼付きやバイア
スライト等が原因となつてその出力電圧に経年変
化を生じる。上記従来装置は、単にＧを基準とし
てＢ、Ｒの黒レベルを設定しているだけであるの
で、Ｇの黒レベルが経年変化で変動すると、Ｂ、
Ｒもその変動したＧを基準として設定されてしま
い、画質を著しく損う問題点があつた。Problems to be Solved by the Invention Generally, television cameras experience changes in their output voltage over time due to burn-in, bias light, and the like. The conventional device described above simply sets the black levels of B and R using G as a reference, so if the black level of G changes over time, the black level of B and R changes over time.
R was also set based on the changed G, which caused a problem that significantly degraded image quality.
本発明は、Ｇ撮像管に対する黒固定回路のクラ
プレベルを可変抑制することにより、経年変化が
あつても良質の画像を得ることができるテレビジ
ヨンカメラの自動黒レベル設定装置を提供するこ
とを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic black level setting device for a television camera that can obtain high quality images even with aging by variably suppressing the clap level of a black fixing circuit for a G image pickup tube. do.
問題点を解決するための手段
第１図中、比較回路４3は緑撮像管の出力に対
する黒レベル平均電圧と基準電圧とを比較して比
較誤差電圧を得る手段、アンプ６Gはこの比較誤
差電圧にて緑撮像管に対する黒固定回路２G′のク
ランプレベルを可変設定する手段の各一実施例で
ある。Means for Solving the Problem In Fig. 1, the comparator circuit 43 is a means for comparing the black level average voltage for the output of the green image pickup tube with the reference voltage to obtain a comparison error voltage, and the amplifier 6G is a means for obtaining a comparison error voltage. This is an embodiment of means for variably setting the clamp level of the black fixing circuit 2 G ' for the green image pickup tube by voltage.
作 用
比較回路４3にて緑撮像管の出力に対する黒レ
ベル平均電圧と基準電圧とを比較して比較誤差電
圧を得、アンプ６Gにてこの比較誤差電圧にて上
記緑撮像管に対する黒固定回路のクランプレベル
を可変設定する。Function Comparison circuit 43 compares the black level average voltage for the output of the green image pickup tube with the reference voltage to obtain a comparison error voltage, and amplifier 6G uses this comparison error voltage to fix black for the green image pickup tube. Set the clamp level of the circuit variably.
実施例
第１図は本発明装置の一実施例のブロツク系統
図を示し、同図中、第２図と同一構成部分には同
一番号を付してその説明を省略する。同図におい
て、基準電圧発生回路７は経年変化のない初期時
のＧの黒検出回路３Gの出力レベルと等しい電圧
（基準電圧）を出力する構成とされている。Embodiment FIG. 1 shows a block system diagram of an embodiment of the apparatus of the present invention. In the figure, the same components as those in FIG. 2 are given the same numbers and their explanations will be omitted. In the figure, the reference voltage generation circuit 7 is configured to output a voltage (reference voltage) equal to the output level of the G black detection circuit 3 G at the initial time without any aging.
基準電圧発生回路７から取出された基準電圧と
黒検出回路３Gの出力電圧とは比較回路４3にて比
較されて比較誤差電圧とされ、ADコンバータ５3
にてAD変換されてアンプ６Gに供給され、比較回
路４3の出力レベルが零になるようにアンプ６Gの
ゲインを可変してＧの黒固定回路２G′のクランプ
レベルを可変設定する。これにより、テレビジヨ
ンカメラの出力に経年変化を生じてもＧの黒レベ
ルは前記初期時の値に設定される。 The reference voltage taken out from the reference voltage generation circuit 7 and the output voltage of the black detection circuit 3G are compared in the comparator circuit 43 to obtain a comparison error voltage, and the AD converter 53
It is AD converted and supplied to the amplifier 6G , and the gain of the amplifier 6G is varied so that the output level of the comparator circuit 43 becomes zero, and the clamp level of the black fixing circuit 2G ' of G is variably set. . As a result, even if the output of the television camera changes over time, the G black level is set to the initial value.
従つて、Ｂ、Ｒの黒固定回路２B，２Rのクラン
プレベルは正常値に可変設定されているＧを基準
に可変設定されるので、経年変化を生じても従来
回路のように画質を損なうことはない。 Therefore, the clamp levels of the B and R black fixing circuits 2 B and 2 R are variably set based on G, which is variably set to the normal value, so even if deterioration occurs over time, the image quality cannot be maintained as with conventional circuits. It won't be damaged.
発明の効果
本発明装置によれば、Ｂ、Ｒの黒固定回路のク
ランプレベルは経年変化のない初期時の値に設定
されているＧを基準に可変設定されているので、
経年変化を生じても良質に画像を得ることがで
き、黒不安定要素を考慮する必要がないので設計
の余裕度を向上し得、特に、電気的増感時の黒バ
ランスずれを生じないので、画質を一段と向上し
得る等の特長を有する。Effects of the Invention According to the device of the present invention, the clamp levels of the B and R black fixed circuits are variably set with respect to G, which is set to an initial value that does not change over time.
It is possible to obtain high-quality images even if changes occur over time, and there is no need to consider black instability factors, which improves the margin of design.In particular, there is no shift in black balance during electrical sensitization. , it has features such as being able to further improve image quality.
第１図は本発明装置の一実施例のブロツク系統
図、第２図は従来装置の一例のブロツク系統図で
ある。
２B，２G′，２R……黒固定回路、３B，３G，３R
……黒検出回路、４1，４2，４3……比較回路、
６B，６G，６R……アンプ、７……基準電圧発生
回路。
FIG. 1 is a block system diagram of an embodiment of the apparatus of the present invention, and FIG. 2 is a block system diagram of an example of a conventional apparatus. 2 B , 2 G ′, 2 R ……Black fixed circuit, 3 B , 3 G , 3 R
...Black detection circuit, 4 1 , 4 2 , 4 3 ... Comparison circuit,
6 B , 6 G , 6 R ...Amplifier, 7...Reference voltage generation circuit.
Claims (1)
青撮像管の出力に対する黒レベル平均電圧とを比
較して得た比較誤差電圧にて該青撮像管に対する
黒固定回路のクランプレベルを可変設定する一
方、該緑撮像管の出力に対する黒レベル平均電圧
と赤撮像管の出力に対する黒レベル平均電圧とを
比較して得た比較誤差電圧にて該赤撮像管に対す
る黒固定回路のクランプレベルを可変設定する機
能を設けられたテレビジヨンカメラの自動黒レベ
ル設定装置において、上記緑撮像管の出力に対す
る黒レベル平均電圧と基準電圧とを比較して比較
誤差電圧を得、該比較誤差電圧にて上記緑撮像管
に対する黒固定回路のクランプレベルを可変設定
する手段を更に設けてなることを特徴とするテレ
ビジヨンカメラの自動黒レベル設定装置。1. The clamp level of the black fixing circuit for the blue image pickup tube is variably set using the comparison error voltage obtained by comparing the average black level voltage for the output of the green image pickup tube and the average black level voltage for the output of the blue image pickup tube. , variably sets the clamp level of the black fixing circuit for the red image pickup tube using the comparison error voltage obtained by comparing the average black level voltage for the output of the green image pickup tube and the average black level voltage for the output of the red image pickup tube. In an automatic black level setting device for a television camera equipped with this function, the black level average voltage for the output of the green image pickup tube is compared with a reference voltage to obtain a comparison error voltage, and the green image pickup is performed using the comparison error voltage. An automatic black level setting device for a television camera, further comprising means for variably setting a clamp level of a black fixing circuit to a tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60109858A JPS61269482A (en) | 1985-05-22 | 1985-05-22 | Automatic black level setting device for television camera |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60109858A JPS61269482A (en) | 1985-05-22 | 1985-05-22 | Automatic black level setting device for television camera |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61269482A JPS61269482A (en) | 1986-11-28 |
| JPH0337258B2 true JPH0337258B2 (en) | 1991-06-05 |
Family
ID=14520977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60109858A Granted JPS61269482A (en) | 1985-05-22 | 1985-05-22 | Automatic black level setting device for television camera |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61269482A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2621099B2 (en) * | 1990-06-21 | 1997-06-18 | 富士写真光機株式会社 | Video signal processing circuit |
| JPH08321970A (en) * | 1995-05-26 | 1996-12-03 | Nec Corp | Black level correction circuitry for television camera device |
-
1985
- 1985-05-22 JP JP60109858A patent/JPS61269482A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61269482A (en) | 1986-11-28 |
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