JPS6337993B2 - - Google Patents
Info
- Publication number
- JPS6337993B2 JPS6337993B2 JP55075134A JP7513480A JPS6337993B2 JP S6337993 B2 JPS6337993 B2 JP S6337993B2 JP 55075134 A JP55075134 A JP 55075134A JP 7513480 A JP7513480 A JP 7513480A JP S6337993 B2 JPS6337993 B2 JP S6337993B2
- Authority
- JP
- Japan
- Prior art keywords
- level
- circuit
- signal
- imaging signal
- low
- 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
- 230000005856 abnormality Effects 0.000 claims description 34
- 238000003384 imaging method Methods 0.000 claims description 30
- 238000001514 detection method Methods 0.000 claims description 18
- 230000002159 abnormal effect Effects 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 5
- 238000005286 illumination Methods 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 230000000007 visual effect Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 206010047571 Visual impairment Diseases 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
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
- H04N23/80—Camera processing pipelines; Components thereof
- H04N23/81—Camera processing pipelines; Components thereof for suppressing or minimising disturbance in the image signal generation
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
Description
【発明の詳細な説明】
本発明はラスタ走査して得た撮像信号の信号レ
ベルの異常を検出する信号レベル異常検出回路に
関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal level abnormality detection circuit that detects an abnormality in the signal level of an imaging signal obtained by raster scanning.
一般に、ラスタ走査して撮像信号を得る例えば
ITVカメラや固体カメラ又はイメージセンサ等
（以下これらを単にセンサと称す）を使用してパ
ターン識別等を実施する場合、撮像信号レベルが
小さ過ぎるとパターンの外形切出しの設定が困難
になり、パターン中の疵検出感度等が低下する。
また撮像信号レベルが大き過ぎると、飽和領域に
入るので残像特性や焼き付きから同様にパターン
中の疵検出感度等が低下すると共に、センサの寿
命低下にもつながるから、撮像信号はそのダイナ
ミツクレンジに対して適当なレベル範囲内になけ
ればならない。 Generally, imaging signals are obtained by raster scanning, e.g.
When performing pattern identification using an ITV camera, solid-state camera, image sensor, etc. (hereinafter simply referred to as a sensor), if the imaging signal level is too low, it will be difficult to set the outline of the pattern, and the Decreases flaw detection sensitivity, etc.
Furthermore, if the imaging signal level is too large, it will enter the saturation region, which will similarly reduce the sensitivity for detecting defects in patterns due to afterimage characteristics and burn-in, and will also shorten the life of the sensor. must be within an appropriate level range.
そこで、撮像信号レベルは、センサを含むシス
テムの出荷時点や現地据付け時点において、入念
に適正レベルになるように調整される。しかし、
撮像信号レベルに関係する例えばカメラレンズの
絞り値（Ｆ値）は、稼動途中でのシステムの保守
や清掃時に自由に変り得るし、またセンサの劣化
や視野内を照明する照明系の劣化により撮像信号
レベルは適正値から容易に変化するから、撮像信
号レベルをそのダイナミツクレンジに対して適当
なレベル範囲内に維持しておくことは困難であ
る。 Therefore, the imaging signal level is carefully adjusted to an appropriate level when the system including the sensor is shipped or installed on site. but,
For example, the aperture value (F number) of the camera lens, which is related to the image signal level, can be changed freely during system maintenance or cleaning during operation, and the image capture may be affected by sensor deterioration or deterioration of the illumination system that illuminates the field of view. Since the signal level easily changes from an appropriate value, it is difficult to maintain the imaging signal level within an appropriate level range for its dynamic range.
その為に従来は、撮像信号のピーク値をホール
ドしてその値と設定光量異常レベル値とを比較
し、設定光量異常レベル値よりもピーク値の方が
大きい場合、信号レベル異常と判定するような信
号レベル異常検出回路を設け、撮像信号レベルを
常時監視してその異常時に警報を発するように対
策を講じていた。 To do this, conventional methods have held the peak value of the imaging signal and compared it with the set light level abnormality level value, and if the peak value is greater than the set light level abnormality level value, it is determined that the signal level is abnormal. A signal level abnormality detection circuit was installed, and measures were taken to constantly monitor the imaging signal level and issue an alarm when an abnormality occurred.
しかしながら、上記従来の信号レベル異常検出
回路は、ピーク値ホールド動作を行なうためノイ
ズ信号に弱く、またハレーシヨンに対する余裕が
ないから僅かなハレーシヨンでもレベル異常と判
定してしまう欠点があつた。一般的に撮像対象物
へ完全な拡散光で照明することは難しくどこかで
ハレーシヨンを起こす場合が多いから、従来方法
では、しばしば誤検出することになり、真の異常
を安定して検出することができない。また撮像対
象物によつては、あえてハレーシヨンを或る程度
発生させるような照明系でなければ疵等が顕著化
しないものがあるけれども、そのような照明方法
を採用することができないという不便もあつた。
更に、ピーク値ホールド回路へのマスキングが困
難なため、センサ観測視野の有効視野以外の周辺
部分からの影響を受け易いという欠点をも有して
いた。 However, the conventional signal level abnormality detection circuit described above has the disadvantage that it is susceptible to noise signals because it performs a peak value hold operation, and also has the disadvantage that even a slight halation is determined to be a level abnormality because there is no margin for halation. In general, it is difficult to illuminate the object to be imaged with completely diffused light, and halation often occurs somewhere, so conventional methods often result in false detections, making it difficult to stably detect true abnormalities. I can't. Furthermore, depending on the object to be imaged, flaws may not become noticeable unless an illumination system is used that intentionally generates halation to a certain extent, but there is also the inconvenience that such an illumination method cannot be used. Ta.
Furthermore, since it is difficult to mask the peak value hold circuit, it also has the disadvantage that it is easily influenced by peripheral parts other than the effective field of view of the sensor observation field.
本発明はこのような従来の欠点を改善したもの
であり、その目的は、ノイズ信号やハレーシヨン
に対して充分な余裕度を有し、真のレベル異常の
みを安定に検出することができる信号レベル異常
検出回路を提供することにある。以下実施例につ
いて詳細に説明する。 The present invention improves these conventional drawbacks, and its purpose is to provide a signal level that has sufficient margin against noise signals and halation, and that allows only true level abnormalities to be stably detected. An object of the present invention is to provide an abnormality detection circuit. Examples will be described in detail below.
第１図は本発明の実施例を表わす要部ブロツク
図であり、１は撮像信号の入力端子、２〜５は比
較回路、６はマスク信号の入力端子、７はインバ
ータ、８，９はアンド回路、１０，１１はパルス
カウント回路、１２，１３は設定値回路、１４は
オア回路、１５はアラーム出力端子、VHは高閾
値、VLは低閾値、ａ〜ｈは各部の信号を示す。
また第２図は第１図示回路を動作させた場合にお
ける撮像信号と比較回路２，３の閾値VH，VLと
の関係を表わす線図であり、２０は黒レベル、２
１は飽和レベル、２３は適正レベルの撮像信号、
２４は過小レベルの撮像信号、２５は過大レベル
の撮像信号、２６は水平同期信号であつて、適正
レベルと過小レベルの間に低閾値VLを設定し、
適正レベルと過大レベルの間に高閾値VHを設定
する。 FIG. 1 is a main part block diagram showing an embodiment of the present invention, in which 1 is an input terminal for an imaging signal, 2 to 5 are comparison circuits, 6 is an input terminal for a mask signal, 7 is an inverter, and 8 and 9 are an AND Circuit, 10 and 11 are pulse count circuits, 12 and 13 are set value circuits, 14 is an OR circuit, 15 is an alarm output terminal, V H is a high threshold value, V L is a low threshold value, and a to h indicate the signals of each part. .
Further, FIG. 2 is a diagram showing the relationship between the image pickup signal and the threshold values V H and V L of the comparator circuits 2 and 3 when the circuit shown in the first diagram is operated.
1 is the saturation level, 23 is the imaging signal at the appropriate level,
24 is an imaging signal of too low level, 25 is an imaging signal of excessive level, 26 is a horizontal synchronizing signal, and a low threshold value V L is set between the appropriate level and the too low level,
A high threshold value V H is set between the appropriate level and the excessive level.
第１図に於いて、必要に応じて増幅又は減衰さ
れた撮像信号ａは、入力端子１から比較回路２，
３の一方の入力端子に加えられる。比較回路２
は、撮像信号ａと他方の入力端子に加わる例えば
第２図に示すような高閾値VHとを比較し、撮像
信号ａが高閾値VHより大きい間その出力を“１”
にすることにより、撮像信号の高レベル異常領域
を検出するものである。また比較回路３は、撮像
信号ａと例えば第２図に示すような低閾値VLと
を比較して撮像信号ａが低閾値VLより大きい間
その出力を“１”にすることにより、撮像信号ａ
が低閾値VL以上に達する領域を検出するもので
ある。 In FIG. 1, an image signal a that has been amplified or attenuated as necessary is transmitted from an input terminal 1 to a comparator circuit 2,
is applied to one input terminal of 3. Comparison circuit 2
compares the image signal a with a high threshold value V H applied to the other input terminal, for example as shown in FIG.
By doing so, high-level abnormal regions of the imaging signal are detected. Further, the comparison circuit 3 compares the imaging signal a with a low threshold value V L as shown in FIG. signal a
This is to detect an area where the value reaches a low threshold value V L or higher.
比較回路２の出力信号ｂは、アンド回路８にお
いて、目的とする視野以外の周辺部等をマスクす
る信号ｃと論理積がとられ、パルスカウント回路
１０に入力される。同様に比較回路３の出力信号
ｄがアンド回路９でマスク信号ｃと論理積をとら
れ、パルスカウント回路１１に加えられる。ここ
でマスク操作を行なうのはセンサ観測視野の有効
視野以外の周辺部分からの影響を受けないように
するためである。パルスカウント回路１０は、ア
ンド回路８の出力信号ｅに含まれるパルス数を一
視野に亘つてカウントし、撮像信号ａが前記マス
ク操作で抽出された所定領域内で高閾値VHに達
した回数を求めこれを比較回路４の一方の入力端
子に出力する。またパルスカウント回路１１は、
アンド回路９の出力信号に含まれるパルス数を
一視野に亘つてカウントし、撮像信号ａが前記マ
スク操作で抽出された所定領域内で低閾値VLに
達した回数を求めこれを比較回路５の一方の入力
端子に出力する。 The output signal b of the comparator circuit 2 is ANDed in an AND circuit 8 with a signal c for masking peripheral areas other than the target field of view, and is inputted to a pulse count circuit 10. Similarly, the output signal d of the comparison circuit 3 is logically ANDed with the mask signal c by the AND circuit 9 and is applied to the pulse count circuit 11. The reason why the mask operation is performed here is to avoid being influenced by peripheral parts other than the effective field of view of the sensor observation field. The pulse count circuit 10 counts the number of pulses included in the output signal e of the AND circuit 8 over one field of view, and counts the number of times the imaging signal a reaches the high threshold value V H within the predetermined region extracted by the mask operation. is determined and outputted to one input terminal of the comparator circuit 4. Further, the pulse count circuit 11
The number of pulses included in the output signal of the AND circuit 9 is counted over one field of view, and the number of times the imaging signal a reaches the low threshold value V L within the predetermined region extracted by the mask operation is determined and this is calculated by the comparison circuit 5 Output to one input terminal of
設定値回路１２には、撮像信号ａが所定領域内
で何回以上高閾値VHに達したとき高レベル異常
と判定するのかの基準となる高レベル異常に関す
る基準値が設定されており、比較回路４は、パル
スカウント回路１０の内容がその高レベル異常に
関する基準値を越えたとき、高レベル異常検出信
号ｇをオア回路１４に出力する。また設定値回路
１３には、撮像信号ａが所定領域内で何回以上低
閾値VLを越えれば適正レベルと判定するのかの
基準となる低レベル異常に関する基準値が設定さ
れており、比較回路５は、パルスカウント回路１
１の内容がその低レベル異常に関する基準値に満
たないとき、低レベル異常検出信号ｈをオア回路
１４に出力する。従つて、オア回路１４からは高
レベル異常検出信号ｇと低レベル異常検出信号ｈ
の論理和信号が出力されることになり、これがア
ラーム出力となる。なお、パルスカウント回路１
１の値は視野観測初期では設定値回路１３の設定
値より常に小さいから、その視野観測初期に低レ
ベル異常検出信号ｈが出力されることになる。そ
こで、視野観測終了時点でアラーム出力をチエツ
クする等の処置を講じておくものである。 A reference value regarding a high level abnormality is set in the set value circuit 12, which is a standard for determining a high level abnormality when the imaging signal a reaches the high threshold value VH within a predetermined area. The circuit 4 outputs a high level abnormality detection signal g to the OR circuit 14 when the content of the pulse count circuit 10 exceeds the reference value regarding the high level abnormality. Further, the set value circuit 13 is set with a reference value regarding a low level abnormality, which is a standard for determining how many times the imaging signal a must exceed the low threshold value V L within a predetermined area to be determined to be at an appropriate level. 5 is a pulse count circuit 1
When the content of 1 does not meet the reference value regarding the low level abnormality, a low level abnormality detection signal h is output to the OR circuit 14. Therefore, the OR circuit 14 outputs a high level abnormality detection signal g and a low level abnormality detection signal h.
A logical sum signal will be output, and this will serve as an alarm output. In addition, pulse count circuit 1
Since the value of 1 is always smaller than the set value of the set value circuit 13 at the beginning of visual field observation, the low level abnormality detection signal h is output at the early stage of visual field observation. Therefore, measures should be taken such as checking the alarm output at the end of visual field observation.
このように本実施例回路は、撮像信号が所定領
域内で低閾値VLにある回数以上達しないか又は
高閾値VHにある回数以上達したときにレベル異
常と判定するように構成されているから、設定値
回路１２，１３のそれぞれの設定値を例えば実際
の対象物を撮像して得た実測データに基づいて統
計的手法により求めておけば、所望のレベル異常
のみを安定に検出することが可能になり、ノイズ
信号やハレーシヨンの影響を受けて誤検出するこ
とは皆無になる。従つて、照明系の自由度が増
し、正確なパターン識別の実施が可能になる。 In this way, the circuit of this embodiment is configured to determine that the level is abnormal when the imaging signal does not reach the low threshold V L a certain number of times or more within a predetermined area, or reaches the high threshold V H a certain number of times or more. Therefore, if the set values of the set value circuits 12 and 13 are calculated using a statistical method based on actual measurement data obtained by imaging an actual object, only the desired level abnormality can be stably detected. This makes it possible to eliminate erroneous detections due to the effects of noise signals and halation. Therefore, the degree of freedom of the illumination system increases, and accurate pattern identification becomes possible.
なお第１図において、アンド回路８の出力信号
ｅとセンサの画面分割クロツクとの論理積および
アンド回路９の出力信号と分割クロツクとの論
理積をとり、これをパルスカウント回路１０，１
１の入力とすれば、高レベル異常領域の面積およ
び低閾値以上の面積が求まる。従つて、設定値回
路１２に許容し得る高レベル領域の最大面積を高
レベル異常に関する基準値として設定し、また設
定値回路１３に適正レベルとして最小限必要とす
る面積を低レベル異常に関する基準値として設定
しておくことにより、画面上の異常レベルの面積
の大小に基づいた異常レベル検出を実施すること
が可能となる。このような構成に依れば、より正
確な検出を行なうことができるものである。 In FIG. 1, the output signal e of the AND circuit 8 and the screen division clock of the sensor are ANDed, and the output signal of the AND circuit 9 and the division clock are logically
If 1 is input, the area of the high level abnormality region and the area above the low threshold value are found. Therefore, the maximum area of the high level region allowable in the set value circuit 12 is set as the reference value for high level abnormalities, and the minimum area required for the set value circuit 13 as an appropriate level is set as the reference value for low level abnormalities. By setting as , it becomes possible to detect the abnormal level based on the size of the area of the abnormal level on the screen. According to such a configuration, more accurate detection can be performed.
以上の説明から判るように、本発明に依れば、
撮像信号が所定領域内で所定回数若しくは所定面
積だけ低閾値以上に達しないか、又は撮像信号が
所定領域内で所定回数若しくは所定面積だけ高閾
値に達したとき、レベル異常と判定するものであ
り、従来の如くピーク値ホールド動作を行なわな
いので、ノイズ信号およびハレーシヨンに対する
余裕度が大きく、安定したレベル異常検出が可能
となる。従つて、本発明回路をパターン識別装置
等に適用すれば、照明系の自由度が増し装置の信
頼性、寿命の向上等が図れて非常に有効である。
なお本発明は先の実施例にのみ限定されるもので
なく、その他各種付加変更し得るものである。 As can be seen from the above description, according to the present invention,
A level abnormality is determined when the imaging signal does not reach the low threshold or higher for a predetermined number of times or a predetermined area within a predetermined area, or when the imaging signal reaches the high threshold for a predetermined number of times or a predetermined area within a predetermined area. Since the peak value holding operation is not performed as in the conventional method, there is a large margin against noise signals and halation, and stable level abnormality detection is possible. Therefore, if the circuit of the present invention is applied to a pattern identification device or the like, the degree of freedom of the illumination system will increase, and the reliability and life of the device will be improved, which is very effective.
It should be noted that the present invention is not limited to the above-mentioned embodiments, but may be modified in various ways.
第１図は本発明の実施例を表わす要部ブロツク
図、第２図は第１図示回路を動作させた場合にお
ける信号波形の一例を表わす線図である。
１は撮像信号の入力端子、２〜５は比較回路、
６はマスク信号の入力端子、７はインバータ、
８，９はアンド回路、１０，１１はパルスカウン
ト回路、１２，１３は設定値回路、１４はオア回
路、１５はアラーム出力端子、VHは高閾値、VL
は低閾値である。
FIG. 1 is a block diagram of a main part showing an embodiment of the present invention, and FIG. 2 is a diagram showing an example of signal waveforms when the circuit shown in FIG. 1 is operated. 1 is an input terminal for the imaging signal, 2 to 5 are comparison circuits,
6 is a mask signal input terminal, 7 is an inverter,
8 and 9 are AND circuits, 10 and 11 are pulse count circuits, 12 and 13 are set value circuits, 14 is an OR circuit, 15 is an alarm output terminal, V H is a high threshold value, and V L
is a low threshold.
Claims (1)
異常を検出する信号レベル異常検出回路におい
て、前記撮像信号を所定の高レベル閾値と比較し
て前記撮像信号の高レベル異常領域を検出する比
較回路、該比較回路出力を処理して前記撮像信号
が前記高レベル閾値に達した回数または面積を求
めるパルスカウント回路、該パルスカウント回路
出力が高レベル異常に関する基準値を越えたとき
高レベル異常検出信号を出力する比較回路、前記
撮像信号を所定の低レベル閾値と比較して前記撮
像信号が該低レベル閾値以上に達する領域を検出
する比較回路、該比較回路出力を処理して前記撮
像信号が前記低レベル閾値に達した回数または面
積を求めるパルスカウント回路、該パルスカウン
ト回路出力が低レベル異常に関する基準値に達し
ないとき低レベル異常検出信号を出力する比較回
路を具備したことを特徴とする信号レベル異常検
出回路。1. In a signal level abnormality detection circuit that detects an abnormality in the signal level of an imaging signal obtained by raster scanning, a comparison circuit that compares the imaging signal with a predetermined high-level threshold to detect a high-level abnormal region of the imaging signal. , a pulse count circuit that processes the comparison circuit output to determine the number of times or area of the imaging signal reaching the high level threshold; and a high level abnormality detection signal when the pulse count circuit output exceeds a reference value regarding the high level abnormality. a comparison circuit that compares the imaging signal with a predetermined low-level threshold and detects an area where the imaging signal exceeds the low-level threshold; and a comparison circuit that processes the output of the comparison circuit so that the imaging signal A signal characterized by comprising a pulse count circuit for determining the number of times or area of reaching a low level threshold, and a comparison circuit that outputs a low level abnormality detection signal when the output of the pulse count circuit does not reach a reference value regarding a low level abnormality. Level abnormality detection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7513480A JPS572171A (en) | 1980-06-04 | 1980-06-04 | Detecting circuit for fault in signal level |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7513480A JPS572171A (en) | 1980-06-04 | 1980-06-04 | Detecting circuit for fault in signal level |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS572171A JPS572171A (en) | 1982-01-07 |
| JPS6337993B2 true JPS6337993B2 (en) | 1988-07-27 |
Family
ID=13567408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7513480A Granted JPS572171A (en) | 1980-06-04 | 1980-06-04 | Detecting circuit for fault in signal level |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS572171A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0728381B2 (en) * | 1982-08-25 | 1995-03-29 | オリンパス光学工業株式会社 | Electronic imager |
| JPH0650906B2 (en) * | 1984-02-24 | 1994-06-29 | オリンパス光学工業株式会社 | Electronic imager |
| JPH0786630B2 (en) * | 1986-12-26 | 1995-09-20 | 富士写真フイルム株式会社 | Aperture drive control method for electronic still camera |
-
1980
- 1980-06-04 JP JP7513480A patent/JPS572171A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS572171A (en) | 1982-01-07 |
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