JPH0153546B2 - - Google Patents
Info
- Publication number
- JPH0153546B2 JPH0153546B2 JP4917880A JP4917880A JPH0153546B2 JP H0153546 B2 JPH0153546 B2 JP H0153546B2 JP 4917880 A JP4917880 A JP 4917880A JP 4917880 A JP4917880 A JP 4917880A JP H0153546 B2 JPH0153546 B2 JP H0153546B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- white compression
- white
- start point
- control circuit
- 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
- 230000006835 compression Effects 0.000 claims description 28
- 238000007906 compression Methods 0.000 claims description 28
- 238000001514 detection method Methods 0.000 claims description 6
- 238000003384 imaging method Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 4
- 238000005070 sampling Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Picture Signal Circuits (AREA)
Description
【発明の詳細な説明】
本発明は撮像装置の映像信号の白圧縮特性を自
動的に調整するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention automatically adjusts the white compression characteristics of a video signal of an imaging device.
撮像装置では、映像モニターのブラウン管の振
幅特性に合わせるために定格振幅以上の映像信号
に白圧縮特性をもたせている。この特性は第１図
に示すように、通常撮像管から取出した映像信号
１に対し、定格振幅Ａから白圧縮特性が開始し、
定格振幅以上の信号を約1/7に圧縮し白圧縮映像
信号１′のような波形を得る。 In an imaging device, a video signal having a rated amplitude or more is given white compression characteristics in order to match the amplitude characteristics of a cathode ray tube of a video monitor. As shown in Fig. 1, this characteristic starts from the rated amplitude A for the video signal 1 extracted from the normal image pickup tube, and the white compression characteristic starts from the rated amplitude A.
A signal with an amplitude greater than the rated amplitude is compressed to approximately 1/7 to obtain a waveform similar to white compressed video signal 1'.
従来、白圧縮特性は手動で調整していた。この
ため、調整時間が長くかかること、常に同じ値に
調整することが困難なことなどの欠点があつた。 Conventionally, white compression characteristics were adjusted manually. For this reason, there were drawbacks such as a long adjustment time and difficulty in always adjusting to the same value.
本発明はこれらの欠点を除去するために、白圧
縮特性を小形計算機を用いて自動的に調整するよ
うにしたものである。 In order to eliminate these drawbacks, the present invention automatically adjusts the white compression characteristics using a small computer.
第２図は本発明の一実施例を示す構成ブロツク
図であつて、１は映像信号、２は誤差検出回路、
３はサンプルホールド回路、４はアナログ・デイ
ジタル変換器、５は小形電子計算機、６，７，８
はデイジタル・アナログ変換器、９，１０は被制
御映像信号の白圧縮開始点レベル制御信号および
白圧縮率制御信号である。 FIG. 2 is a configuration block diagram showing an embodiment of the present invention, in which 1 is a video signal, 2 is an error detection circuit,
3 is a sample and hold circuit, 4 is an analog-to-digital converter, 5 is a small electronic computer, 6, 7, 8
1 is a digital-to-analog converter, and 9 and 10 are a white compression start point level control signal and a white compression rate control signal of the controlled video signal.
ここで各制御信号９，１０は撮像装置の白圧縮
制御回路（図示せず）に入力される。 Here, each control signal 9, 10 is input to a white compression control circuit (not shown) of the imaging device.
この動作はまず、誤差検出回路２で、被制御映
像信号１（定格の３倍ののこぎり波テスト信号）
と小形電子計算機５で作られデイジタル・アナロ
グ変換器６でアナログ信号に変換された白圧縮開
始点用基準レベル（第３図のＡ）とを比較し、そ
の差信号を検出する。この差信号出力は、サンプ
ルホールド回路３で、小形電子計算機５からの第
３図ａに示すサンプルパルスP1，P2によつて対
応した２カ所における差信号レベルがサンプリン
グホールドされ、各々アナログ・デイジタル変換
器４で変換され小形電子計算機５に供給される。
小形電子計算機５では、この２カ所でサンプリン
グした差信号のレベルが等しくなるような制御信
号を算出し、デイジタル・アナログ変換器８を経
て、白圧縮制御回路に制御信号１０を供給する。
これに基づいて白圧縮制御回路で映像信号１の制
御がなされる。この動作は上記２カ所における差
信号レベルが等しくなるまで反復される。 This operation begins with the error detection circuit 2, which uses the controlled video signal 1 (a sawtooth wave test signal three times the rated value).
and a white compression start point reference level (A in FIG. 3) created by the small computer 5 and converted into an analog signal by the digital/analog converter 6, and the difference signal is detected. This difference signal output is sampled and held in the sample and hold circuit 3 by sample pulses P 1 and P 2 shown in FIG. It is converted by a digital converter 4 and supplied to a small electronic computer 5.
The small computer 5 calculates a control signal that makes the levels of the difference signals sampled at these two locations equal, and supplies the control signal 10 to the white compression control circuit via the digital-to-analog converter 8.
Based on this, the white compression control circuit controls the video signal 1. This operation is repeated until the difference signal levels at the two locations become equal.
この結果、映像信号１は、第３図ａに矢印で示
すように制御され、１′のようになる。次に、同
様にして、第３図ｂに示すようなサンプリングパ
ルスP3を小形電子計算機５からサンプリングホ
ールド回路３に供給し、このサンプル位置での白
圧縮映像信号１′と基準レベルＡとの差信号レベ
ルをアナログ・デイジタル変換器４を介して小形
電子計算機５に供給する。小形電子計算機５で
は、このサンプリングホールドした差信号レベル
が０になるような制御信号を算出し、デイジタ
ル・アナログ変換器７を経てこの制御信号９を白
圧縮制御回路に供給する。この動作は、このレベ
ル差が０になるまで反復される。この結果、映像
信号１は、第３図ｂに矢印で示すように制御さ
れ、１″のようになる。 As a result, the video signal 1 is controlled as shown by the arrow in FIG. 3a, and becomes 1'. Next, in the same manner, a sampling pulse P3 as shown in FIG. The difference signal level is supplied to a small electronic computer 5 via an analog-to-digital converter 4. The small electronic computer 5 calculates a control signal such that the sampled and held difference signal level becomes 0, and supplies this control signal 9 to the white compression control circuit via the digital/analog converter 7. This operation is repeated until this level difference becomes zero. As a result, the video signal 1 is controlled as shown by the arrow in FIG. 3b, and becomes 1''.
次に第３図ｃに示すような映像信号の白映像部
分のできるだけ後端に位置するサンプルパルス
P4を小形電子計算機５よりサンプルホールド回
路３に供給する。さらに小形電子計算機５はデイ
ジタル・アナログ変換器６を介して誤差検出回路
２に第３図ｃのＢで示す白圧縮映像振幅用基準レ
ベルを発生する。そして、この基準レベルＢと映
像信号１″は誤差検出回路２で比較され、その差
信号がサンプルホールド回路３でサンプルホール
ドされ、アナログ・デイジタル変換器４を経て小
形電子計算機５に供給される。ここで小形電子計
算機５はこの差信号が０になるような制御信号を
算出し、デイジタル・アナログ変換器８を経て白
圧縮制御回路にこの制御信号１０を供給する。こ
の動作は差信号が０になるまで反復される。 Next, a sample pulse located at the rear end of the white video portion of the video signal as shown in FIG.
P4 is supplied from the small electronic computer 5 to the sample hold circuit 3. Furthermore, the small computer 5 generates a white compressed video amplitude reference level shown at B in FIG. 3c to the error detection circuit 2 via the digital-to-analog converter 6. This reference level B and the video signal 1'' are compared in an error detection circuit 2, and the difference signal is sampled and held in a sample and hold circuit 3, and is supplied to a small computer 5 via an analog-to-digital converter 4. Here, the small computer 5 calculates a control signal such that this difference signal becomes 0, and supplies this control signal 10 to the white compression control circuit via the digital-to-analog converter 8.This operation is performed so that the difference signal becomes 0. is repeated until .
この結果映像信号１は第３図ｃの１のように
なる。 As a result, the video signal 1 becomes as shown in 1 in FIG. 3c.
以上の動作の結果得られた、制御信号９，１０
を最終的白圧縮制御値すなわち、第３図ｂのＡを
定格映像振幅、第３図ｃのＢを白圧縮映像振幅と
して小形電子計算機５の内部に記憶させておくこ
とによつて白圧縮特性は自動的にしかも、常に一
様に調整できる。 Control signals 9 and 10 obtained as a result of the above operations
are the final white compression control values, that is, A in FIG. 3b is the rated image amplitude and B in FIG. can be adjusted automatically and uniformly at all times.
なお、前述の動作は、小形電子計算機５に設定
したプログラムにしたがつて行なわれる。 Note that the above-mentioned operations are performed according to a program set in the small computer 5.
以上説明したごとく、本発明によれば、撮像装
置の白圧縮特性の自動調整に際し、特殊な階段状
テスト信号を必要とせず、確実に、しかも常に一
様に、短時間で調整でき、撮像装置の各種調整の
自動化に適用して有効である。 As explained above, according to the present invention, when automatically adjusting the white compression characteristics of an imaging device, the adjustment can be made reliably, always uniformly, and in a short time without requiring a special step-like test signal. It is effective when applied to the automation of various adjustments.
第１図は映像信号の白圧縮特性を示す波形図、
第２図は本発明の一実施例を示すブロツク構成
図、第３図は本発明の動作説明用波形図である。
１：被制御映像信号、２：誤差検出回路、３：
サンプルホールド回路、４：アナログ・デイジタ
ル変換器、５：小形電子計算機、６，７，８：デ
イジタル・アナログ変換器、９，１０：制御信号
である。
Figure 1 is a waveform diagram showing the white compression characteristics of the video signal.
FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a waveform diagram for explaining the operation of the present invention. 1: Controlled video signal, 2: Error detection circuit, 3:
Sample and hold circuit, 4: analog/digital converter, 5: small electronic computer, 6, 7, 8: digital/analog converter, 9, 10: control signal.
Claims (1)
る所定のテスト用映像信号と小形電子計算機に設
定された白圧縮開始点用基準レベルとの差信号を
検出し、上記小形電子計算機によつて、該差信号
出力の所定期間隔たつた２ケ所における該差信号
のそれぞれの検出レベルが等しくなるような白圧
縮率制御信号を算出するとともに、該信号を上記
白圧縮制御回路に上記テスト用映像信号制御用信
号として供給し、これによつて制御された上記テ
スト用映像信号の所定位置における信号レベルが
上記白圧縮開始点用基準レベルに等しくなるよう
な白圧縮開始点用制御信号を算出・記憶するとと
もに、該信号を上記白圧縮制御回路に白圧縮開始
点用制御信号として供給し、これによつて制御さ
れた上記テスト用映像信号の白映像部分の最後端
位置における信号レベルが上記小形電子計算機に
設定された白圧縮映像振幅用基準レベルに等しく
なるような白圧縮率制御信号を算出・記憶すると
ともに、該信号を上記白圧縮制御回路に白圧縮率
制御信号として供給し、これによつて上記白圧縮
制御回路を自動制御することを特徴とする撮像装
置の白圧縮特性自動調整方法。1. Detect a difference signal between a predetermined test video signal obtained from an imaging device having a white compression control circuit and a reference level for a white compression start point set in a small computer, and use the small computer to A white compression ratio control signal is calculated so that the detection levels of the difference signal at two points with a predetermined interval between outputs of the difference signal are equal, and the signal is sent to the white compression control circuit to control the test video signal. calculating and storing a control signal for a white compression start point such that the signal level at a predetermined position of the test video signal controlled by the signal is equal to the reference level for the white compression start point; At the same time, the signal is supplied to the white compression control circuit as a white compression start point control signal, and the signal level at the rear end position of the white video portion of the test video signal controlled by this signal is set to the small electronic computer. Calculates and stores a white compression ratio control signal that is equal to a white compression video amplitude reference level set at A method for automatically adjusting white compression characteristics of an imaging device, comprising automatically controlling the white compression control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4917880A JPS56146367A (en) | 1980-04-16 | 1980-04-16 | Automatic control system for white compression characteristic of pickup device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4917880A JPS56146367A (en) | 1980-04-16 | 1980-04-16 | Automatic control system for white compression characteristic of pickup device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56146367A JPS56146367A (en) | 1981-11-13 |
| JPH0153546B2 true JPH0153546B2 (en) | 1989-11-14 |
Family
ID=12823793
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4917880A Granted JPS56146367A (en) | 1980-04-16 | 1980-04-16 | Automatic control system for white compression characteristic of pickup device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56146367A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58164368U (en) * | 1982-04-26 | 1983-11-01 | 日立電子株式会社 | Television camera characteristic automatic adjustment device |
-
1980
- 1980-04-16 JP JP4917880A patent/JPS56146367A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56146367A (en) | 1981-11-13 |
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