DE2035893C3 - Method and device for suppressing noise in an infrared camera - Google Patents
Method and device for suppressing noise in an infrared cameraInfo
- Publication number
- DE2035893C3 DE2035893C3 DE2035893A DE2035893A DE2035893C3 DE 2035893 C3 DE2035893 C3 DE 2035893C3 DE 2035893 A DE2035893 A DE 2035893A DE 2035893 A DE2035893 A DE 2035893A DE 2035893 C3 DE2035893 C3 DE 2035893C3
- Authority
- DE
- Germany
- Prior art keywords
- infrared
- detector
- beam path
- signals
- amplifier
- 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
- 238000000034 method Methods 0.000 title claims 5
- 230000001360 synchronised effect Effects 0.000 claims description 4
- 230000001629 suppression Effects 0.000 claims description 2
- 230000005855 radiation Effects 0.000 claims 4
- 230000003321 amplification Effects 0.000 claims 1
- 238000009529 body temperature measurement Methods 0.000 claims 1
- 230000003247 decreasing effect Effects 0.000 claims 1
- 230000006866 deterioration Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 claims 1
- 238000005562 fading Methods 0.000 claims 1
- 230000002349 favourable effect Effects 0.000 claims 1
- 238000003199 nucleic acid amplification method Methods 0.000 claims 1
- 238000011144 upstream manufacturing Methods 0.000 claims 1
- 238000005070 sampling Methods 0.000 description 2
- 238000005259 measurement 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
- H04N23/20—Cameras or camera modules comprising electronic image sensors; Control thereof for generating image signals from infrared radiation only
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Radiation Pyrometers (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
Description
Ausgang 8 des Verstärkers 7 ergibt sich dann ein mit Rauschanteilen verschiedener Frequenzen angereichertes Signal (Kurvenzug 22 in F i g. 4), bei dem vor allem die tief ffequenten Rauschanteile eine starke Veränderung und Verzerrung hervorgerufen haben.Output 8 of amplifier 7 then results in a with Noise components of different frequencies enriched signal (curve 22 in FIG. 4), in which before In particular, the low-frequency noise components caused a strong change and distortion.
Um nun diese Verzerrungen zu beseitigen, wird jeweils zu den Zeiten, in denen dem Strahlengang des Detektors 6 die Bezugsflächen 11 der Umlaufblende 3 eingeblendet sind, durch einen Xaktgeber 5 ein synchrones Tastsignal erzeugt, mit dem eine Schwarzsteuerschaltung 9 beaufschlagt wird. Diese stellt einen konstanten Bezugspegel für die vom Verstärker? erhaltenen Signale her, indem die bei der Messung der Bezugsflächen 11 erhaltenen Signale wieder auf einen konstanten Ausgangswert gebracht werfen.In order to eliminate this distortion, the times when the beam path of the Detector 6, the reference surfaces 11 of the rotating screen 3 are faded in by a clock generator 5 a synchronous key signal is generated, with which a black control circuit 9 is applied. This provides a constant reference level for the amplifier? signals obtained by the signals obtained during the measurement of the reference surfaces 11 throw brought back to a constant starting value.
Auf diese Weise ergibt sich an einem Signalausgang 10 ein in F i g. 5 durch den Kurvenzug 23 dargestellter Signalverlauf. Es ist ersichtlich, daß das am Signalausgang 10 anstehende verstärkte Detektorsimdzwar noch die hochfrequenten Rauschanteile enthält, daß jedoch die störenden niederfrequenten Rauschanteile um so stärker unterdrückt sind, je tiefer sie bezüglich ihrer Frequenz im Vergleich zu der Tastfrequenz liegen.This results in a signal output 10 in FIG. 5 represented by the curve 23 Waveform. It can be seen that the amplified detector present at the signal output 10 is indeed still contains the high-frequency noise components, but that the disturbing low-frequency Noise components are suppressed to a greater extent, the lower they are with regard to their frequency in comparison to the Sampling frequency lie.
Diese Tastfrequenz, die der Frequenz, nut der die Bezugsflächen in den Strahlengang des Detektors 6 gelangen, entspricht, kann leicht durch Veränderung der Drehzahl des die Umlaufblende antreibenden Motors gesteuert werden. Zweckmäßig ist es jedoch, die Drehzahl so festzulegen, daß nach jedem BiIdpunkl, einem Bruchteil eines Bildpunktes oder einer Vielzahl von Bildpunkten der Infrarot-Kamera ein Bezugssignal erzeugt wird. Durch Variation der Tastfrequenz wird gleichzeitig das Maß der Unterdrückung der niederfrequenten Rauschteile gesteuert.This keying frequency, that of the frequency, the use of the Reference surfaces get into the beam path of the detector 6, corresponds, can easily by changing the speed of the motor driving the rotating shutter can be controlled. However, it is useful to set the speed so that after each picture, a fraction of a pixel or a large number of pixels of the infrared camera Reference signal is generated. By varying the sampling frequency, the degree of suppression is also increased of the low-frequency noise parts controlled.
Hierzu 1 Blatt Zeichnungen 1 sheet of drawings
Claims (3)
konstantes Bezugspotential bringen. Die Einrichtung zur Durchführung des Verfahrensthe, characterized thatinan fade-in of a reference surface with a constant, known manner at regular intervals temperature has become known "Electronics world", the in the beam path of the infrared detector xo October 1967, p. 23 to 27 and W); However, (6) a reference surface (11) with cootant temperature, this measure is displayed there for the purpose of emergence and that at the same time precise temperature measurement and display. The lower one behind the amplifier (7) to suppress the harmful noise was in contrast acted upon with the help of additional pulses in the known black control circuit (9) with pushbutton arrangement, which reached the additional filters of the reference 15 on a path that leads signals corresponding to area values away from the solution according to the invention,
bring constant reference potential. The facility to carry out the procedure
die synchron mit der Zeilenfrequenz im Zeilenrück- 60 Während Fig. 2 den zeitlichen Verlauf des durch lauf erfolgt. Weiterhin bekannt ist, daß dabei die das Objektiv 2 tretenden Strahlungsflusses mit dem Störsignale, die eine kleinere Frequenz als die Zeilen- Kurvenzug 20 wiedergibt, stellt der Kurvenzug 21 in frequenz aufweisen, unterdrückt werden. Fig. 3 den zeitlichen Verlauf der vom Detektor 6When watching television, the black value control radiation is known to generate a reference signal corresponding to the temperature of the tion to restore the constant component, surfaces 11 in the detector 6,
which is synchronized with the line frequency in the return line. It is also known that the radiation flow entering the lens 2 with the interference signals, which reproduces a lower frequency than the line curve 20, the curve 21 represents in frequency, are suppressed. 3 shows the time profile of the detector 6
vor, bei dem in an sich bekannter Weise in regeimäßi- Die im Infrarot-Detektor 6 eingehende StrahlungTo solve the above-mentioned object, the radiation received is suggested, with only amplitude values being plotted in the ordinate-rich invention for an infrared camera,
before, in which in a known manner in regeimäßi- The incoming radiation in the infrared detector 6
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2035893A DE2035893C3 (en) | 1970-07-20 | 1970-07-20 | Method and device for suppressing noise in an infrared camera |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2035893A DE2035893C3 (en) | 1970-07-20 | 1970-07-20 | Method and device for suppressing noise in an infrared camera |
Publications (3)
Publication Number | Publication Date |
---|---|
DE2035893A1 DE2035893A1 (en) | 1972-01-27 |
DE2035893B2 DE2035893B2 (en) | 1972-06-22 |
DE2035893C3 true DE2035893C3 (en) | 1973-01-04 |
Family
ID=5777286
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE2035893A Expired DE2035893C3 (en) | 1970-07-20 | 1970-07-20 | Method and device for suppressing noise in an infrared camera |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE2035893C3 (en) |
-
1970
- 1970-07-20 DE DE2035893A patent/DE2035893C3/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE2035893B2 (en) | 1972-06-22 |
DE2035893A1 (en) | 1972-01-27 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
C3 | Grant after two publication steps (3rd publication) | ||
E77 | Valid patent as to the heymanns-index 1977 | ||
EHJ | Ceased/non-payment of the annual fee |