DE2416483B2 - INFRARED VIEWER - Google Patents

Description

11. Infrared vision device according to one of the preceding claims, characterized in that the telescope (120) is preceded by a directional mirror (52) which directs the incident radiation from the scene to be observed into the telescope.

The invention relates to a infrared vision device with a telescope, a scanning mirror arranged on the image side of the telescope, which in executes a scanning movement in a first direction, and in a second direction in relation to the direction of the scanning movement perpendicular direction extending detector group and one coupled to the detector group Display device for generating an image of the scanned. Scene made up of synchronization pulses and time-division multiplexed video signals Makes use.

In one known from DT-OS 23 31 102 Infrared vision device is assigned an emitter group to the detector group, which has just as many emitter elements Like the detector group, it contains detector elements. Each emitter element is via an amplifier channel a video electronics connected to an associated detector element and emitted visible light with an intensity that differs from the intensity of the associated detector element radiation received. The visible light generated by the emitter group is over

an associated area of the scanning mirror of a television camera supplied so that on the image storage disk The television camera generates an image that corresponds to the image generated by the infrared radiation and which is electronically scanned by the television camera in the usual way. By this electronic scanning is generated in time-division multiplex video signals, which are then transmitted to the actual display device, thus a television set, can be fed. The television camera also produces the synchronization signals required to synchronize the display device.

With the known infrared vision device, «-Jso a double image conversion takes place, namely once the conversion of the image recorded by the infrared detectors of the infrared radiation into the visible image produced by means of the emitter group and the scanning mirror and the subsequent conversion this visible image by means of a television camera into electrical signals necessary for reproduction are suitable by means of a television display device. Every image transformation inevitably has one This results in a loss of quality and also requires considerable effort. In particular, is at light infrared vision devices use a television camera that requires high supply voltages requires, very annoying. Also make the optical means necessary for the double image conversion the known device is extensive and expensive.

The invention is based on the object of providing an infrared viewing device of the type described at the outset to improve that a multiple image conversion with the associated effort is unnecessary.

This object is achieved according to the invention in that a signal processor is provided which a device for deriving the synchronization pulses directly from the scanning movement of the Scanning mirror and multiplexers that work in real time and are coupled directly to the detector group for generating the video signals, which includes the detectors of the detector group in a specific one Scan the sequence in succession, each scan being characteristic of a data line in the second direction and a certain number of data lines during each scan of the scene in the first direction is generated, and that the display device to the synchronization pulses generated by the signal processor and respond to video signals.

In the infrared vision device according to the invention there is a direct conversion of the signals supplied by the detector elements into video signals, and the syndhronization signals are derived directly from the movement of the scanning mirror, for which purpose suitable sensors can be used. All optical devices going beyond the receiving optics are avoided, as are complex electron beam devices. The to. The signal processor used to generate the video signals in time division multiplexing can essentially be constructed from semiconductor components so that it can be accommodated in the smallest of spaces and does not require high operating voltages. The power requirement of such devices also remains low, so that the infrared vision device according to the invention can have a relatively small size and also a low weight. This fact is of outstanding importance for many purposes.

The simple structure of the infrared vision device according to the invention offers the possibility of creating additional facilities with simple means, such as inscribing an adjustable crosshair that is accurate and very reliable indication of the viewing direction in the displayed image guaranteed. There is still the possibility to compensate for disturbances resulting from an image of the strongly cooled detectors ίο result from reflective surfaces of the optics on themselves and because it is a kind of viewing of one's own mirror image through the detectors, hereinafter referred to as Narcissus images will.

Further details and configurations of the invention emerge from the following description of the embodiment shown in the drawing. The description and the drawing too In other Ausao features derived from the invention can be implemented individually or several can be used in any combination. It shows

F i g. 1 the schematic representation of a helicopter with a forward-looking infrared viewing device,

F i g. 2 a schematic representation of a rotatable shooter seat as an example of the application an infrared viewing device,

F i g. 3 the block diagram of an infrared viewing device,

F i g. 4 shows a block diagram to explain the sensor system used in an infrared viewing device,

F i g. 5 a schematic and partially exploded perspective illustration of a sensor unit;

F i g. 6 shows a schematic, perspective illustration of the opto-mechanical arrangement of the sensor unit according to FIG. 5 omitting housing parts,

F i g. 7 a schematic representation of the beam path in the optical system in the azimuth plane,

F i g. 8 a schematic representation of the beam path in the optical system in the elevation direction;

F i g. 9 shows, partly in side view and partly in section, the drive arrangement for an azimuth mirror the sensor unit according to FIG. 5,

Fig. 10 is a schematic side view for explanation the mode of operation of an alternating mirror of the sensor unit according to FIG. 5,

11 is a schematic side view for explanation an adjustment mirror of the sensor unit according to FIG. 5,

FIG. 12 is a schematic view of the adjusting mirror according to FIG. II along the line 12-12,
F i g. 13 a schematic, enlarged illustration of a slave arm of the adjusting mirror arrangement according to FIG. 11,

Fi g. 14 is a schematic side view of a synchronization generator the sensor unit according to FIG. 5,

F i g. 15 is a schematic view of the synchronization generator according to Fig. 14 along line 15-15,

16 is a schematic side view of the field of view switching device the sensor telescope in the position for a narrow field of view,

17 shows a schematic side view of the field of view switching device of the sensor telescope in the position for a wide field of view.

18 shows a schematic, perspective illustration a detector arrangement subdivided into sections, as is the case with the sensor unit according to FIG. 5 can be used,

19 shows a schematic representation for the purpose of illustration a signal source for Narcissus image compensation and automatic sensitivity control in the detector part of the system,

20 shows a schematic, perspective illustration for further explanation of the Narcissus image compensation,

21 shows a schematic, perspective illustration for further explanation of the automatic sensitivity control,

Fig. 22 is a schematic illustration of the further Explanation of the signal source for sensitivity control, .... "...".

23 shows a schematic section through the Signal source for automatic sensitivity control according to Fig. 22

24 shows a schematic, perspective illustration for further explanation of the automatic speed control

25 is a schematic circuit diagram of a modulator of the device for automatic sensing, from which it can see from a field of view can absorb walking energy. The pulpit that turns you in a helicopter can act, a suitable scanning device that can act the gaze field 14 scans horizontally while aligning; on the selected field of view in azimuth durcl Turning the pulpit and in elevation by setting a directional mirror takes place The Richtsysten

can have a stabilized cardanic suspension on position and speed circles as well as responding to directional commands as it is generally known in tech technology. In the illustrated Aus example, the azimuth scanning is carried out lengthways!

such lines as lines 21 and 23 during a first scan and along such lines as ^{lines 25} and 27 during a second scan for alternate field operation. The field of view can contain various objects such as

_ao for example a vehicle 19

I _n Fig. 2 is showing a pivotable Schützenplatz. u- the use of an infrared vision device; _in a helicopter or a slow FIu ₂ tool. The arrangement includes

, 5 the pulpit 12, which is on a part 40 of the helicopter

for further ^automatic Erläute ^Em P ^f -dlich-

Sre ^ r ^{8 ZUr AUTOMATIC EM} P ^f -dlich- for example a shooter, LlSem Stuhf 44S

kertseregulation, can. The pulpit 12 may have an exterior window 50

FIG. 27 shows a range of services for further development, which is, for example, based on Germa him

auterung of the automatic sensitivity ^ - can stand. A right mirror 52 SS

A * 28. and 28b together das.Blockschalt- Α ^^^ ΪΑ ^ Α

St ^{g ZUr SlgnaJverarbeitUn} S of ^the initiation causes. The one from the mirror

Circuit diagram de, filter- "SSS ^ VSfi ^ ^ em infrared senso,

^{Multiple level} ^

of a fast multiplex

Fig.31 shows the schematic circuit diagram of a control "logic of the device according F i g. 28,

F i g. 32 is a timing diagram for explanatory signals the timing of the device

33 and 34 timing diagrams of signals for " Explanation of the time control of the vertical image structure with an infrared viewing device,

35 and 36 timing diagrams of signals to explain the timing of the automatic, 0 see sensitivity control and the SteueTune "of the horizontal image structure, ^g

F i g. 37 the block diagram of a display device used in the infrared viewing device,

38 is a schematic representation of the screen of the display device according to Fig. 37 and

F i g. 39 a schematic representation of? Explanation of the cooling device for the detector arrangement of the viewing device. ^e

Passive infrared vision devices are used, for example, in vehicles, for example an aircraft 10, shown in FIG. 1, overflying part of the earth's surface. The aircraft has SseT neAjntirseite a rotating cockpit lf, Te is aimed at a desired location on the earth's surface 14 or in the field of view. The plane 10 can en helicopters, fixed-wing aircraft, a ^ dJ an IV ™

Be machines moving in one position

fc iLwe _e en ^ 62 connected to the gas, such as Freon.

hold nl \ f
S _n T'so d ft
Periscope #

gg
^D - ^S f ^UI W ^{advises 68 to} "

Axis of the ISeL Γα ^V0 ^ ^es f, ^he "'
K ^ l 12 and in T T, '"f ^U "?

^ ™ ^ ¹ ; ¹³ , ^{88 Pe} " ^SkOP? °

dr-fnS ,. ^ t α ^gC ' ^{contain the light of} 68 t ν ^ f ⁵ ^^' ^{in the} display device

Λ ^ ^ ^An invention suitable, ^{St. ellu} ° ß ^s - ^and speed

wuTdfs block SS f? T -κ ·,. ,, · ", _T , ^S ^ 'ocKschaltbdd according to Fig. 3 shows,

outer window ' lt e ^ nf ^V °° ^der , ^S ? f ^ne ,? ^un * ^d * S? received and supplied via the direction S * f \ sensor unit 74, as indicated by A »R * ° P ^tlsc ^ n paths 79 and 81. iird a N- ^ rΪ? η ^^ ^ei "P ^ genen energy

vom Sussien Fn \ ΐΤ-ί ^ ⁸ ? ^{16 paths? 8} "f *! L ^S ° ^{over the Rlchts} P ^ie g ^{el and}

⁷⁴ « ^inflected · ^egg " ^Si P ^aI '

₈₆ t T ί - the ^{video signal on an} 86. that for a sensor unit with Λ ⁷ De-

7 8

detectors N separate lines, one for each leads. The beam splitter 142 allows a portion of the infra video signal to be included. A cable 88 transmits suitable red signals. It also receives from nete scan sync signals which, at the system shown, a source 160 and reflected from the optics, form an azimuth scan sync signal which encompasses the shape of the outline of the narcissus. A display device 90 receives in 5 image has to cancel out the video signals combined by the optics and the alternating multiplex on a cable mirror 140 received Narcissus image, 92 and synchronization signals on a cable 94, to what is indicated by the multiplier 162 . on the screen of a suitable cathode ray tube The Narcissus image will produce a raster-shaped image towards the darstel. A suitable processing device reflects and is extinguished under a certain optical device or a periscope 70 receives io th scanning angle, which can be achieved, the image of the display device 90 so that it is perpendicular to the optical axis to a user for example through the eyepiece 72 when the mirror surface is perpendicular to the optical axis. The source 160 can also be viewed by a modulator. The system shown environmentally 168 is used, the Vo 90 from the source 160 geliefaßt a power supply unit 98 and a helium compressors ferten receives power, the signal obtained modusor 64. Both units are lines via a cable 99 and 15 on the surface of the Beam splitter 142 is controlled by a control panel 102 . Advantage from the control, from the 8 to 10 Vo by the spectral filter frame 102 is a brightness control signal 146 to the detector array 150 as a signal for automatic through a line 104 to the display device 90, a look sensitivity control (ARC) signal Reflectors-contrast Control signal via a line 106 that enables independent control of the amplification processor 82 and a field of view switching signal in response to the N channels of the system. The output is fed to a line 108 of the sensor unit 74 . The output signal of the detector group is transmitted to the N line for setting a display of the viewing direction, which lines of the cable 86 to the signal processor 82 is located on the image surface of the display device. A cooling unit 170 is connected to the cold shield, directives 148 , which can be set manually by the user, and the detector group 150 are connected. These signals on a cable 112 from the control panel 102 25 cooling unit can connect the above-mentioned helium comder sensor unit 74 and the signal processor 82 to the compressor 64 according to FIG. 3 included. The control of the guided to adjust the vertical and the horizontal gaze sensor unit takes place with the help of a line of sight direction. lers 171, who made a setting of the field of view of the Fig. 4 shows the block diagram of the sensor telescope 120 and the setting of the line of sight 74. As shown in FIG. 4, depending on a selected visual infrared sensor system, the fitting comprises a telescope 120 which enables the field. Motors 174, 176 and 178 drive infrared radiation originating from the scene through the horizontal scanning mirror 122 or which the outer window 50 receives via the directional mirror 52, the vertical directional mirror 136 or the alternating mirror (FIG. 3). 140 receives from this telescope.

a horizontal scanning mirror 122 and that of FIG. 35 FIG. 5 shows a schematic perspective scene as well as the representation of the sensor unit, derived from the Narcissus picture, with infrared radiation for the sake of simplicity. To create a synchronicity of the representation of expanded parts. As can be seen from the sationssignals, the energy source 126 leads the sensor unit to a housing 180 chronization generator 127 to the horizontal scanning, which is attached in the pulpit and connected to the telescope mirror 122 , which supplies energy from the horizontal down 40 120 which reflects the infrared signal from the probe mirror and receives it from a receiver 128 directional mirror and recorded by a field of view and as a synchronization signal via selector unit 182 , which is driven by a servomotor 172 a line 130 to a suitable amplifier 132 . The infrared signal is then supplied by, which then supplies it as a synchronization pulse to the telescope 120 to the horizontal scanning mirror via the cable 88 to the signal processor 82 45 122, which is shown with its Motc: 174. The scene and Narcissus image signals are then fed to the mirror surface 137 of the vertical directional mirror from the horizontal scanning mirror 122 to a vertical 136 and from there to the Altemier mirror 136 , which reflects a setting 140. The signal is then made possible by the alternation of the vertical guideline, which is mirror 140 to beam splitter 142 and from this like the line of the B-directional representation, 5 ° to the speculars forming the input window, which extends in the horizontal direction. Both the tralfilter 146 reflects. As can be seen, the source scene and the Narcissus image signal are arranged by 160 for the Narcissus signal in such a way that the vertical directional mirror supplies an alternating mirror 140 with energy to the beam splitter 142 , which is then supplied to the beam splitter 142 serves to alternate the location of the scan lines to the modulator 168 to generate a reference of the field of view while successive Azi 55 signals are received for the gain control, as shown in FIG. 1 The detector assembly 149 comprises a Dewa: has been explained. The scene signal is transmitted from 190 to the non-visible detector group, which is located in a housing 192 by means of a beam splitter 142 in front of the alternating mirror 140 . A suitable junction box 19 'made of optical material and a permeability 60 with cables which are used to lead out the N lines of 90 ⁰ Zo and a reflectivity of 8 to from the detectors are routed to the housing, which is for example made of a coated 192. Another connection 10 ⁰ O can have. The input window takes a box 198 evacuated to a suitable electrical Kabe Dewar, which is up the detector array for an opening 199 of the housing 180 for Her and is shown as a spectral filter 146, can provide electrical connections are provided. The Mo have such a selected thickness that there is only 65 gate 176 for the vertical directional mirror has an infrared energy of a selected working area adjusting shaft for the vertical directional mirror 136 and through a "suitable cold screen 148 a function for adjusting the vertical Direction of view «tekior arrangement 149 of a detector group 150 in line in the illustration, on the optical axis

from the telescope 120 to the housing 180 a

10

SSnZV ⁰² Γ ⁸ « ⁰ · ' ^{1161 Sei} ?' the metal parts have a large heat coefficient, which changes their linear expansion with temperature fluctuations Ein Dekl 210 it Ab

as well as reflect the rays that arise

Τ "" ^tHe ° ^{bjektiv from} einem'einzigen brecifenden
Germanium link consists. The scanning mirror 122 is located a certain distance from the
Dtkt 150 Ξ g

, re linear expansion at temperature is found in a certain distance

Change fluctuations. A cover 210 is for the 5 detector group 150 to Ξ through the

A F i g. 6 are the opto-mechanical ropes

BHckfclcbefindeΓ ^ ϊ

** ^Em P ^findli <* l «it to improve the detectors

and serves to determine the position of the telescope 120 along eSn and

to change the optical axis, and with one window that

Aperture 220, which can be present in some arrangements to limit the viewing angle or the detectors

' ^around

^ trained
^ ^οΙ1 ^ ^ηαΐ 8 concludes.

WärmekompensatoV 202 angfordnei to the _Fe ^ tube 120 with changes in temperature along the od ™. _s see axis shift zS so that ^g that di! Focus setting is retained. The horizontal AbS mirror 122 carries out a scanning movement in azimuth, as indicated by an arrow 224, S £ Λ SzTne is scanned in the range of the entire azimuth scanning angle K <on the detectors which are arranged in the Elevati ™. The signal received by the horizontal scanning mirror 122 is fed to the vertical directional mirror 136. folded, the Ai, ^;!. Mirror 140 supplied, folded again and reflected on the beam splitter 142 so that the Elevaticnsrichtung extends in the direction of the line formed by the De detector group, which is located in the detector arrangement 149. The scene is alternately fed to the detector group in the detector arrangement 149 from two partial images which are generated alternately by interlacing. ^{e S}

The F i g. 7 and 8 show an azimuth and elevation arrangement of the sensor unit, the function of which will now be explained in more detail, with the path of the optical beams. In the azimuth view, F i _ε 7, the window 50 _is shown in a straight line before the Femrohr. In the elevation view according to FIG. 8, the optical system between the diaphragm and the detectors is also shown with a straight optical axis in order to improve the clarity of the drawing. The rays at a long distance and at the far field of view are shown by zoned or dashed lines. The corresponding positions of the field of view selection unit are also shown by continuous and dashed lines. When operating with a wide field of view, a triplet of three spaced germanium elements is inserted between a simple optical element for a narrow field of view and the diaphragm by rotating the triplet 90 ° to align its axis with the optical axis 230 of the single link for the narrow field of view or lens 121. It should again be noted that the dashed lines both the field of view selector unit 182 in position to create a narrow field of view

S> SthHriW de? _lt ^Ab ; » ^te P «8f ' ^{122 dem}
' ^{the Alterniers} P> egel 140, the

S Ε ^ ΐ * the ^{window U6}

d _he anSrht Hp I, ■ ν ^l _f ^elweise broken SeitengeT 122 AHT _a 't ^ ^en "" fn ^ ntal-Abtastsp.ebewirkt / x / ^{is, by a cam}
a ί ^ ΐΐ ^ 254 ^ T '"τ ^ Ά ^ ^ l
the ileänen wave seat J ^ τϊ ι Ϊ ™
A η ν I ^der ^ ° ^{cken 250} ' ^an S ^e "
$?.?! "^" ^A i? ^the "cam 250 is below the

L ^ ^P ft ¹²² _u ^fastenl g ^l ^ * o that the

fct S aJJihS? t Ä ²⁵ ° ^rotates · ^{The cam}
«De? ff '^ ^{6 the Abt} ^ tspiegel during

tastbewLn f ^ ^{g of the N} ° ^{Ckens a! inear Ab} "
S · ! ^ ^N ß ^a " ^sf V ^{hrt and} during the remaining

£ wii ^ Ϊ ^{en angles 268 are} indicated,
* ™ * ^{π returns to the} starting position. The mirror

eela _e m cd ^ 'lT "^ f ^{5 on axis 2} " ⁷⁰

Schwenk Wer ^ T ** ^1Se ™ ^{dnem flexib} ' ^en
ZIt? be provided. The scanning mirror

iS ™ f ρ nl Ύ ™ ^{Frec luence v} ° n 60 Hz and performs that
S n _rH ^ho ™ ^tal about the detector group
klnn! ^{: The} . ^d ™ cam 250 driving motor 174
motor Ip- ^ h ^ ^running hysteresis-SynchronuntSeteenripfrT? ^m ^ ° ^{Cken about a} sixfold
Dif in "-? N ^ ^ebe S ^eko PP ^elt is

V Ii ^S - S ^{represents Esteli} te arrangement for turning ^{A1! erni} mirror 140 includes a perrna-

SfSS ^ ^ ^{2? 1} ' ^the " ^{vischen E} ' ^ektr0 '
^{d 73 bewe} § ^ba r "" d is en ^erbund with the ALTER, 7th To Laeerune the arrival ^V ^ S ^Bonds with the Ältemlerspiecel
Srf ^ n Vi ^U " ^{d 276 The La2e of the} alternating ττβ,! \ 7-7 - ^{1St d} ^? ^{Ei by a} suitable leaf spring
dnrr ^ -: Z \ ? | ^{r anchor 15} ^ eS ^{1 län} ^ s des
nferVnw? f given Weses. De ^ age-Jon, mV ^ t ^V ° ^{U the GaN} ₂ ssi ₂ n; ie, nes mono-Ii I ι ^^ «« «βογ driven"; and ^ echde, νΤΆ ^'beis g ^slightest, about 6 ms after occurrence
<™ ι _η - ™ ^{£ Π Rl} ™ ^tlm P ^uls es as a Folre of one in the Sidem riaii ^{Μ (Ιηιμ} Verzöaeruneskreises. Bei

MteVnip «- vfJ.» ^{Execution is > ie!} 'changes
^ ^uer nierspiegel 140 his Ste! luncu-a'hr »nHH ^ RiirV-

zi NA

ai F ei w

ei A Iu di di 3 »ai is

P <ei bi m A se sp

en ei] so

to Se eii

Sy off in ke

t,
η
O

return of the scanning mirror to the starting position. The alternating mirror can with respect to the optical device be arranged so that it can only pivot through an angle of 0.5 mrad needs.

11, 12 and 13 show the arrangement for adjusting the vertical directional mirror 136. The Motor 176 moves the vertical directional mirror 136 in response to a vertical directional signal that from is fed to control panel 102 (Fig. 3) over a certain angle when the system is on by rotating a slot assembly 282 about an axis 283. A Follower arm 284 rests on a pin 286 which, when the field of view is narrow, has a first position 288 and at A second position 290 occupies a wide field of view, as is determined by an arm 292 which extends to the servomotor 172 responds for the field of view adjustment. Arm 292 is through pin 286 a relatively stiff lever 287 is connected and is pivotable about an axis 296. A spring 294 holds the Arm in the position assigned to the narrow field of vision, provided that the servomotor 172 is not in the position shown by solid lines. The directional mirror 136 is about a stationary axis 304 pivotable and follows the movement of the follower arm 284. In the illustrated embodiment is l'v movement of the motor 1.76 for the directional mirror By hard stops (not shown) and a coupling to an angle range of ± 45 ° limited. This is used to fine-tune the elevation or vertical guideline in the Ahtastraster the motor 176 energizes to a total pivot of the Richtipiegel to effect the example can be about 10 °. When adjusting the vertical guideline when the field of view is narrow has taken place, the correction is retained when the system by means of the servomotor 172 on the large Field of view is switched. It was found that the effect of fine adjustment on focus is negligibly small.

The synchronization generator is now illustrated with reference to FIGS explained in more detail. It comprises a transmitter 312, which can be, for example, a gallium arsenide diode, a sensor 314, which can be, for example, a silicon diode, and a reflector or Deflecting mirror 316, which can be a suitable spherical reflector. All these We assembled "" wirVen with the scanning mirror 122. The transmitter 312 cooperates with a suitable direct current source and forms a continuous wave radiation source. The sensor 314 carries current signals from a suitable electronic unit 320 too, which includes an amplifier and vertical sync pulses generated. When the scanning mirror 122 passes a certain position, a synchronization pulse is generated educated. The energy emanating from the transmitter 312 is transmitted to the scanning mirror 122, and from there to the deflecting mirror 316 reflected back onto the scanning mirror 122 and then onto the sensor 314 when the scanning mirror 122 assumes a certain angular position. This synchronization pulse that occurs during each azimuth scan generated by the scanning mirror is used in the system for displaying the horizontal bar a crosshair to synchronize the horizontal display, the display blanking and the drive used for the Altemier mirror. The shape of the vertical sync pulse, the appears on a line 322 is determined by the size of the aperture of the transmitter 312 and the angular velocity of the scanning mirror is determined.

The switching of the field of view will now be explained in more detail with reference to FIGS. 16 and 17 will. When working with a narrow field of vision, the servomotor 172 takes the position shown in FIG. 16 so that the light does not pass through the wide-angle cell 234 of the field of view selection unit 182, but only the lens 121 for the narrow field of view. With the setting illustrated in FIG. 17 to a large The field of view is the wide-angle cell 234 of the servomotor 172 about an axis 236 in such a position panned so that the triplet creates a large field of view. The arrangement includes a switch 238, which switches off the motor in every end position, and a stop 240 for the two operating positions of the wide-angle cell 234.

The detector group 150, which comprises three detector sections 332, 334 and 336, will now be explained in more detail with reference to FIG. The individual detectors, such as detectors 338 and 339, for example, can be photoconductive elements. Each detector section may be constructed so that a plate of detector material is soldered to a Kovar carrier and the Kovar carrier is attached to a sapphire insulator to provide electrical insulation. The detectors are then manufactured by an etching process, by means of which material is removed from between the individual detector elements. The electrical contact to each detector element can be brought about by making a wire connection to a printed circuit (not shown). Suitable cold shields are provided, such as cold barriers 340 and 342, which have a stack of N slots in front of each detector. These slits form an effective opening for a noticeable reduction in scattered photons. It should be noted that other suitable cold screens can be used with such a device. By dividing the detector group into detector sections 332, 334 and 336, improved focusing of the optical system is achieved.

The extinction is now based on FIGS. 19 and 20 of the Narcissus picture explained. The reflectivity of the elements of the optical system, including of the window 50 and all other reflective optical elements, even if an anti-reflective coating is used, high enough to get an image of the detectors on the window unc other optical elements on the scanning mirror and back to the cold entry window of the Dewa and to reflect to the detector group. Since the Azi mut scanning mirror between the detector group around the optical system is arranged, a Nar ziß-3ild is generated when the scanning mirror perpendicular to the optical axis. While the scanning is mirroring · η moves from one side to the other, win the pattern of the optical links resulting from the internal temperature of the detector! faintly imaged on the detectors when the scanning mirror is perpendicular to the optical axis This disruptive heat pattern is caused by the low reflection factor of the coated window

13 ¹⁴

heavily muffled. The sensitivity control, which is kept at lowest temperatures, delivers the intended detectors within the cold shielding similar, modulated inin.iüi-r.czü ^ ignai lur aie, however, because of this very low temperature, have automatic! to nälen of the signal processor of the device D _ie in the high-sensitivity setting of 5 Detek- main function oer automaüscheri Empfindhchkeitstoren to be more visible in a sufficiently strong Wännekontrast all N Karatur. There is then an image of the localization, the sensitivity of all the deciss images does not take place, because the detectors in the detector elements of the group are based on the same value at the focal point of the lens. Accordingly, this can be achieved by setting the gain of each channel em system a weak BUd of a detector enclosure. Although this setting could be made with the help of the normal to the optical axis or with selected damping conditions, when scanning parallel to the outer window, this would require continuous manual adjustment. Some arrangements may require satisfactory operation of the device. flexion of Narcissus image to some extent, the automatic sensitivity control effected by tilting the outer window loading a continuous adjustment of the lifetime hummed angle can be prevented during a and it can be in 15 the Detektorgmppe and saves N manual egg some arrangements, _n the picture of the detector out of position. Furthermore, the automatic allows half of the narrow field of view to be placed. Even sensitivity control, the replacement of certain arrangements, however, the image of optical parts of the system appears without the detectors being monitored when the wide field of view has to be sensitivity adjustment. is posed. The Narcissus image is not generated by ao automatic sensitivity control makes the window, but also by the optical system by monitoring the sensitivity of each de, including the tektorkanals for two fields of view and the automatic control of the telescope. The path of the Narcissus image after channel enhancement to achieve uniform reflection at the optics is shown in Fig. 20 through an image use. The arrow 345 indicated by the modulator 168. The path of the energy of the scar 15 supplied signal illuminated uniformly all Detekziß signal source to the optics and gates after reflection and, together with the out of view back to the beam splitter by the arrow 347 field incident energy, a composite Siwiedergegeben. gnal that is amplified. That from the modulator

In the illustrated arrangement the reference signal supplied by Narcissus 168 is in each channel of the

Signal source 160 with a suitable, variable 30 signal processor from the composite signal

Energy source 158 connected to a temperature and pulled out with the help of a synchronous detector

to generate which in the illustrated system approximately rectified to pin DC control signal

640 ° K and obtained by the infrared ray, which is proportional to the sensitivity.

The control signal is then fed to a diode 146

was reflected by the optics, and to the detection 35 the gain control glicd in each Signalverstüj-

gates by moving from the source 160 to the optics, fed through ker. The system also enables a

the beam splitter 142 and through the window 146 through contrast adjustment in a large area

is enough. In this way, a vertical image 163 changing the intensity of the energy generated by the source 160

the Narcissus signal source generated which delivered the cold signal.

Deletes the narcissus image or at least its effects. Since the beam splitter 142 indirectly transmits the infrared radiation supplied by Narcissus and 90% of the energy incident on its surface to the beam conductor 142 and a modulated one, a substantial proportion of the source 160 emitted by the slot 350 to a reflecting mirror surface Radiation to modulator 352. This path is shown by lines 358 and 364 168 for automatic sensitivity control 45. A tuning fork-like, vibrating fed. The 8 to 10 ¹ Vo of the beams, which are reflected by the shutter 360 in front of the mirror surface 352 arranged beam splitter, are sinusoidally modulated by the net and depending on a driving sensor optical system back to the detector arrangement inflected from the slit 350 to effect the erasure of the narcissus image and thus the intensity of the rewiring. The energy source i58 can be variable, 50 inflecting infrared signal with a frequency of so that the source 160 is in the range of the desired 45 Hz Detector group 150 can be changed in order to optimally erase the modulated Siziss image indicated by lines 364 and also reflect an ordinary contrast signal that can be set as a common reference signal. In Fig. 20 the optics are shown as 55 being routed through all channels of the system. Although an optical unit 344 is shown in order to move from the beam splitter 142 to only 8 to 10% of the modulus, so that all optical elements are reflected during operation, the energy obtained contributes to the Narcissus effect. It is especially important that the Narcissus processor is sufficient for use as a reference signal in the signal tone. The image appears on the detectors through the beam splitter and that at this 60 urgent modulated energy is scattered and the cancellation stnttfiprW from the same scanning position. added to the system.

uas self-image only appears with such a structure and the mode of operation of the module

Palpation position in which the intra-red Jbnuigie m uci oulators 168 are illustrated with reference to FIGS. 22, 23 and 24

giving a normal to the window or along the explained in more detail. The mirror 352 is on a carrier

normal optical axis is received. S5 attached near the slot 350, which is made by strips 363

With reference to FIGS. 21 and 19, the we- and 365 is limited, / τ the ends of the carrier

According to the automatic sensitivity regulation, tuning forks 367 and 369 are attached

treatment treated. A signal source for the automa- arms or tines each with one of the strips 363

15 16

and 365 are connected. Each tuning fork has 45 Hz from the push-pull synchronous detector

a control unit 371 or 373, which is suppressed with one in 368 , so that the Bezuessienal for the

Fig. 25 shown connected circuit arrangement and sensitivity control during processing

and is used to control the tuning forks in such a way that the image signals are not disrupted

em that it causes it to oscillate at the desired frequency.

gen and open and close the slot. Each The signal processor, whose block diagram the

Control unit includes drive coil 375 and FIG. 28 a and 28 b show, includes the circuit

an anchor 377 extending from the arm or tine assemblies for converting the N detector

the tuning fork extends into the drive coil, signals received by the sensor unit

and can add another coil 379 and an armature, into a single line, one by time division multiplexing

387 for supplying a feedback signal for the video signal received. In addition, the

grasp. The control unit 389 for the tuning fork 367 signal processor the synchronization signals for the

includes similar armature and coils 381 and 383. Display device and the synchronization and

The two tuning forks 367 and 369 are driven by drive signals for the source of the reference signal for

a connecting bar 342, which by means of a zen- 15 the sensitivity control and the aging

central leaf spring 366 is attached to a carrier, mirror in the sensor unit. The signal processing

held. makes of a two-stage multiplex processing

As the circuit diagram of FIG. 25 shows, the N signals supplied by the detector group becomes a modulation signal which uses a frequency of 45 Hz. The first stage of the multiplex processing has, from the line 372 via a coupling ao takes place in units that are arranged in groups of N / 4 channels capacitor esnem integrator of the drive signal source to a video output signal for each 193, which generates a sinusoidal signal that to create a unity. Each of the cables 780 to 783 is fed to an amplifier 38'il which comprises drive signals for / V / 4 individual lines for each Λ74 which generates the drive coils 379 and 381. The other detectors used. The units 785 to 788 coils 375 and 383 generate negative feedback »5 respond to the approval signals for the input of the amplifier 380 via the cables 780 to 783 , lead signals and generate each during around the quality and the response time of the circuit to a clock interval a single output signal, decrease. If the unit 785 is considered, the modulation of the Narcissus signal with a frequency contains a power unit 790 W / 4 amplifiers and the synchronous frequency of 45 Hz. 30 detector unit 792 Λ '/ 4 detectors, each of which

As shown in the block diagram of the device with the amplifier of the corresponding channel for automatic sensitivity control according to bound isi, and a multiplexer 794, the N / 4Schal-F i g. 26, the detector group receives ter and contains a shift register in which a control 150 energy from the modulator 168 is shifted as a function of the impulse A through N / 4 flip-flops in order to be controlled by a synchronization circuit 370, each of which is a different one in succession / V / 4 detector to put a source of a signal at the frequency of signals on an output line 398 . The 45 Hz acts, and from a contrast control signal, units 786, 787 and 788 are also formed, which is fed to the device 374 on a line 372 from a contrast control as well as the unit 785 and supply signals. The signals formed by the detector input lines 400, 401 and 402. The pulses from group 150 are then transmitted via * o clocks I, II, III and IV result in a filter characteristic unit 785, the detectors in the N lines 1, 5, 9, 13, etc., fed in the post pre-amplifier 376, the training unit 786, the detectors 2, 6, 10, 14, etc., in the input signals to a synchronous detector 378 fed to unit 787, the detectors 3, 7, 11 , 15 etc. and in, which causes an individual control of the amplifier unit 788, the detectors 4, 8, 12, 16 etc. to reduce the N preamplifiers. The synchronous 45 is sampled, the signals of which are then sent to the detector 378, receiving from the synchronizing switching lines 398, 400, 401 and 402 given evaluation 370 a reference signal at 45 Hz to a synch. The synchronous detection units, how to effect the synchronous detection of the modulated signals , are received as synchronous detectors are supplied to the synchronous detectors. corresponding lines 410 and 412 antiphase

From the preamplifier 376 50 train signals of 45 Hz are also fed by a counter-clock converter over N signals on separate lines to a multi- 414, which feeds a signal from a 1: 8 splitter 418 empplexer 380 , which captures these N signals. A 360 Hz generator 415 conducts an alternating video signal, which is fed to a video amplifier 382 current signal, a square-wave converter 416 iu, from and further to a mixer 384. In which the signal is then sent via the 1: 8 divider 4118 to become dependent on a cancellation signal that arrives at the push-pull driver 414. The 1: 8 divider 418 synchronizing circuit 370 is supplied, the feeds the 45 Hz signal also on a line 420 mixer 384 to the reference signal for the sensitive to a driver 422 , which in turn is based on a power control, the, in the system was used. tung 772 the signal of the reference signal source in which the video signal is then supplies the sensor unit 384 from the mixer. A variable direct current is supplied to the display device 90, which provides a contrast control 423 that provides a visual signal and generates the image that is viewed 432 on a line 430 by the user of the driver 422 and a reference signal cancellation circuit, for example through a telescope to, to can be. reliable deletion of the reference signal

Like F i g. 27 shows, contains the reference signal for the ensure. The regulation of the reference signal be-sensitivity regulation, the frequency of which is 45 Hz 65, the amplification in the N channels is correct and that amounts, no odd harmonics, to the large extent of the contrast in the display. A

times the frame rate of the illustrated system of square to sine converter 434 receives which are 45 Hz-30 Hz. The even harmonics of the frequency signal from the 1: 8 divider and carries a sinusoidal signal

to the reference signal cancellation circuit 432, which is a regulated amplifier which is responsive to the Contrast control signal responds. A clear signal is provided on line 434 to summing amplifier 440 to remove the reference signal from the video signal S.

The video signals supplied by the four slow multiplexers are sampled synchronously by a fast multiplexer 450. The multiplex frequency is chosen with respect to the azimuth sampling frequency so that all N detectors are scanned during each azimuth resolution element of the display. Since the fast sampling for the very slow multiplexers takes place at different times, the clock signals for the slow * 5 multiplexers are delayed so that the sampling of the four slow multiplexers takes place at times when their output signals have maximum values. The output lines 398, 400, 401 and 402 feed the video output signals to the high-speed multiplexer 450 via a buffer 452, which may contain four ao delay lines. Multiplexer 450 includes four high speed switches controlled by clock signals G 1, G 2, G 3 and G 4. The purpose of the buffer 452 is to reduce the compensation signals produced by the switching processes.

A quartz clock 458 feeds clock signals to a ring counter 460, the outputs of which are fed to a decoder 462 _; d ** r signals Gl, Gl, G 3 and G 4 to a driver 464 and the multiplexer 450. Furthermore, clock signals are fed to a logic 468 which generates the control signals A, B, C and D, a synchronization signal for the vertical display on a line 469 and a vertical delete signal on a line 471. A binary counter 472 also responds to the quartz clock 458 and supplies signals for controlling the logic 468. Furthermore, the counter 472 is supplied with a reset signal from the logic 468 via a reset logic 474. The video signal is fed from the multiplexer 450 on a line 480 to the summing amplifier 440 and from this via a line 482 to the display device 90. In addition to the cancel signal on the line 436, the summing amplifier 440 receives a directional synchronization signal on a line 484 and a horizontal canceling pulse on a line 486. The summing amplifier 440 can be formed by a conventional operational amplifier, which has a number of parallel input resistors, which with connected to the input terminal, and whose input terminal is connected to the output terminal via a bypass resistor. The directional synchronization signal of the synchronization generator 127 is fed on a line 488 to an amplitude discriminator 490 and from this to a directional delay circuit 492, a horizontal synchronization delay circuit 494 and an alternating delay circuit 496. The directional delay circuit 492 can be variable and have parallel delay branches which can be selected via line 493 from the field of view selector 171 (FIG. 4), so that the signal is added to the video signal in the correct manner that the horizontal directive as vertical line written on the screen of the cathode ray tube. A gate 498 is responsive to the delayed alternate signal to place the delayed directional signal on line 484 only during every other field. A one-shot 4199 is responsive to the horizontal sync delay circuit 494 to provide horizontal alignment pulses on line 486. The signal from the monoflop 499 is also fed to the display device as a synchronization signal on a line 513. A monoflop driver 504 responds to the output signal of the alternating delay circuit 496 and forms alternating control signals on lines 515 and 517 for the alternating mirror, which are phase-shifted by 180 ° with respect to one another, and a display alternating signal on a line 518 fed via a gate 506 on a line 519 to the output of the detector of the central channel in order to generate the vertical directional signal for the display. A reversing switch 510 is used to supply signals to the motor for the vertical viewing direction in the sensor unit for a movement in the desired direction for setting the vertical guideline.

In Fig. 29, it is the one having a filter characteristic Amplifier and multiplexer shown for a single channel pointing to a detector 522 responds, which may be detector # 1 of detector group 150. Of the Amplifier includes a transistor 524 of the PNP type, the emitter of which is through a suitable resistor and a parallel capacitor connected to ground and its collector connected to a capacitor is connected to the input line 526 of an operational amplifier 528. The output signal of detector 522 becomes the base of transistor 524 and, via a resistor 530, the collector of the transistor, which in turn is connected to a voltage source via a resistor 531 is. The other input of operational amplifier 528 is connected to ground. To the exit a line 536 is connected. The input line 526 is connected to a capacitor 538, which in turn is connected to a bridge comprising two diodes 540 and 542 connected in series are connected so that the cathode of one and the anode of the other diode with a common Connection point 541 are connected, while the other anode or cathode with capacitors 544 and 546 are connected, of which the capacitor 546 is at a common connection point 545 and is connected to a line 548. The anode of the diode 540 is with a Line 550 connected. Line 536 connected to the output of the operational amplifier is connected via a resistor 554 to a connection point 549, which in turn is via a line 547 with the connection point 545 between the two capacitors 544 and 546 in connection stands. The connection point 549 is also connected to ground via a resistor 560 as well as via a resistor 562 is connected to the input line 526. Line 548 is with the collector a MOS field effect transistor 570 acting as a switch, while the line 550 is connected to is connected to the collector of a MOS field effect transistor 572, which also acts as a switch. the Both field effect transistors form the synchronous detector 571 for the automatic sensitivity control. The emitters of the field effect transistors 570 and 572 are connected to line 536 through a low-pass filter. The Gatts of the field effect transistors

sn ve si} fü V

sti 5 '

^S ? si}

ur be ch de at ds W W in

Ψ an de sa 54 sa ve 54 Lt W Ri sei ge

m (bii un W da du rel W W Gi ητ Ai bi

ge sp 5C

ing
earth
gsiin
gsnd
nd
in the
? sct-
19th
ils

i n
> r
ir

are each connected to one of the lines 410 and 412, on which the anti-phase rectangular signals from push-pull driver 414 (Fig. 28). With the line 536 is "also a Bias source 575 connected.

In operation, the gain of operational amplifier 528 is determined by resistors 562, 554 and KiQ and the impedance of diodes 540 and 542. The switches formed by the field effect transistors 570 and 572, which form the synchronous detector 571, are in equilibrium when the reference signal for the sensitivity control has a certain amplitude and the current through the diodes 540 and 542 is fixed. In the event of a change, for example a decrease in the amplitude of the reference signal detected by the synchronous detector 571, the current flowing through the diodes 540 and 542 decreases, so that the impedance formed by one of the diodes decreases and the ratio between the resistors 554 and 560 increases. In this way, the gain of each individual channel is automatically regulated as a function of the reference signal which is processed by the synchronous detector 571.

Accordingly, depending on the drive signals, one of the field effect transistors with the frequency of the reference signal is turned on while the other is blocked, and vice versa. The effect of the synchronous detector is to charge the capacitors 544 and 546 so that the diodes 540 and 542, which are connected in series with said capacitors in parallel, in the forward direction be traversed by electricity. The diodes 540 and 542 are preferably silicon diodes with low Leakage current, and it becomes their resistance to an AC signal from which is flowing through them Quiescent current determined. For example, the AC impedance of diodes 540 and 542 can be 26, divided by the quiescent current in milliamps. So if the ones on the capacitors 544 and 546 pending voltage is sufficient to generate a quiescent current of 1 μΑ through the diodes then the AC impedance of these diodes would be about 26,000 ohms.

The connection point 545 common to the two capacitors 544 and 546 is with the connection point 549 of the voltage divider formed by the resistors 554 and 560. Of the The value of the resistors 554 and 560 is chosen so that that from the connection point 549 to the connection point 545 applied AC signal has a relatively low value. For example, the Resistor 554 has a value of 1000 ohms and resistor 560 has a value of 10 ohms. Of the The reason for this is that optimum operating characteristics with minimal distortion are obtained when the Amplitude of the AC signal supplied to junction 545 on a preselected, is kept relatively low level, for example at a peak voltage of about 50 mV. The AC signal coupled across diodes 540 and 542 is taken from junction 541 via capacitor 538 to the input line 526 of the operational amplifier 528.

For the mode of operation of the circuit arrangement for automatic gain control according to In Fig. 29, it is important that the gain of this circuit arrangement is a function of the feedback impedance between the output line 536 and the input line 526. The value of this Feedback impedance and thus the gain of the circuit arrangement is determined by the alternating current impedance of diodes 540 and 542 is determined as a function of the strength of the power supplied to the diodes Stromes is. The synchronous detector 571 supplies this which determines the impedance of the diodes 540 and 542 Direct current as a function of the level of the reference signal in the output signal on the line 536.

With regard to the polarity, the circuit arrangement is shown in FIG. 29 structured in such a way that when that Reference signal on output line 536 increases; the control current in diodes 540 and 542 also increases. Because the alternating current impedance of the diodes is an inverse function of the amount flowing through them Direct current has an increase in the output

a ° signal and the resulting increase in the Control current results in a decrease in the alternating current impedance of the diodes, so that the input of operational amplifier 528, a stronger negative feedback current can be supplied can, whereby the gain of this stage decreases.

As indicated above, the AC signals applied to diodes 540 and 542 are intended to be on a small, predetermined levels are kept, for example at a peak voltage of 50 mV, to keep distortion to a minimum. For this purpose an AC coupling of the Diodes are made to a virtual output that is determined by the voltage divider with resistors 554 and 560 is formed. For example, in a typical application, resistor 554 may be a Value of 1000 ohms and the resistor 560 have a value of 10 ohms. As a result, a Achieved reduction in the amplitude of the signal fed to the diodes by about 100: 1.

A feature of the described system is to provide a circuit arrangement for automatic sensitivity control, which is responsive to a reference signal having a specific, predetermined frequency in order to maintain a specific gain in a processing channel, but which is not responsive to a data signal which is processed simultaneously with the reference signal will. When operating the circuit arrangement according to FIG. 29, the balanced push-pull synchronous detector 571 is controlled by driver signals which are fed to the gates of the field effect transistors 572 and 570, so that the synchronous detector generates an effective output signal only from input signals with the frequency of the driver signals or their odd harmonics (F i g. 27). Output signals that could be generated by input signals with even harmonics of the frequency of the drive signals are eliminated due to the balanced push-pull structure of the synchronous detector. In an imaging system, the data signals must have frequencies that are multiples of the vertical scanning frequency, that is to say frequencies of η · 30 Hz in the embodiment under consideration, where 11 is an integer. As a result, the data signals cannot contribute to the output signal of the synchronous detector 571 unless a state occurs in which a multiple of the vertical scanning frequency /

is equal to an odd multiple of the drive signals fed to the gates of the field effect transistors. In other words, data signals cannot contribute significantly to the gain control as long as / i-30 = w-45, where η is any integer and m is an odd integer.

The amplified signal on the line 536 is then fed via a suitable low-pass arrangement to a line 580 and then to a slow multiplex switch 582 which contains MOS field effect transistors 584 and 586 as switches, the collectors of which are connected to the line 580, the emitters to the output line 398 and whose gates are connected to a line 588. The multiplex switch 582 is controlled by a suitably biased driver transistor 590 from a flip-flop 592, which is the first flip-flop of the type described in the description of FIG. 28 mentioned shift register can act. The flip-flop 592 receives a clock signal as well as a control signal / !, which can be fed to the (7 input of the flip-flop. In this way, according to the control signal A during every fourth clock period, the signal on the line 536, which has been determined and has its gain controlled, is sampled and sampled on the output line 398 so that it can be fed to the high-speed multiplexer 450 (Fig. 28) The shift register can contain N / 4 flip-flops, such as flip-flops 592 and 593, of which only flip-flop 592 receives control signal A and at where the input and output terminals are swapped for each subsequent flip-flop.

FIG. 30 shows one of the high speed switches that can be used in multiplexer 450. The signal to be switched is supplied on line 398 which, after passing through buffer 452 (FIG. 28), is supplied to the anode or cathode of diodes 521 and 523, the cathode or anode of which with the cathode or anode of diodes 525 and 527. The anodes of the diodes 523 and 527 are connected via a resistor to a terminal to which the signal G 1 is supplied, The cathodes of the diodes 521 and 525 are also connected via a resistor to a terminal to which the signal UI is supplied. the output signal is supplied from the anode and cathode of the diodes 525 and 527 of the conduit 480 which is connected through a resistor to generate a suitable bias voltage to ground. a similar switch may be on the multiplexed signals of the first stages of all Multiplexers 794, 795, 797 and 799 address.

The logic functions and the timing of the device discussed will now be described with reference to FIG. The ring counter 460 contains / tf flip-flops Z18 and Z19, which respond to the quartz clock 458 and continuously perform a binary count. The decoder 462 contains NAND gates G 1, G2, G3 and G4, which respond to the output signals ZIS, ZI9 and Z18, ZI9 and ZIg. Address Z19 or Z18, Z19. The driver 464 contains NAND gates G 29 to G 32, the output signals of which are the signals clock I, clock II, clock III and clock IV. The elements Gl, G 2, G 3 and G 4 supply synchronization signals for the high-speed multiplexer, which are referred to as signals Gl, G 2, G 3 and G 4. The signal G1 is fed to a gate G 7 and negated in order to form a clock signal C 2. The clock signal C 1 is the output signal of the quartz clock 458. The binary counter 472 contains / K flip-flops Z1 to ZN, each of which responds to the clock signal Cl to count in the usual manner. The reset logic 474 contains a flip-flop Z 20, which supplies a reset signal via a member GIl to the flip-flops, such as the flip-flops Zl and Z2, and via a member G12 to flip-flops, such as the flip-flop ZiV. A member G9 responds to the signals Zl to ZN and supplies a signal via a member G 8 to the control input of the flip-flop Z 20 and a NOT member G 10 dem. X input of flip-flop Z 20. Member G 8 also receives clock signal C 1.

The logic 468 contains a member G 27 which responds to the signals Z1 to ZN and supplies a signal to a member G 28 which negates the signal and sends it to the line 469 as a synchronization signal for the vertical deflection. The logic 468 also includes

such a member G 15 for generating erase signals, which responds to the signals Zl to ZN and whose output signal is fed to a member G16. The output signal of the element G 16 is then sent together with the clock signal Cl to a element G 26

supplied, which generates the cancellation or blanking signal for the vertical deflection on line 471. A member G 13 responds to the signals Z1 to ZN and feeds a signal to a member G 17, the output signal of which is fed to member G 26. That

The output signal of the element G13 is also fed to a element G14, the output signal of which is combined each with one of the clock signals 1 to IV elements G18 to G 21 is supplied. With the Links G 18 to G 21 are each one of links

G 22 to G25 connected, which negate the output signals of the elements G 18 to G 21 and form the control signals A to D.

Curve 475 in Fig. 32 shows that the horizontal blanking after the conclusion of this display

lur.gsrasters is done. During each of the vertical scans represented by curve 477 a vertical line is formed in the display. A vertical synchronization signal according to curve 652 defines the vertical scanning.

while the horizontal sync signal is represented by curve 655. Every horizontal scan according to curve 479 defines a horizontal field that is one line from the other is offset. The control signal for alternating the

Fields according to curve 653 are fed to the alternating mirror on line 517 (FIG. 28).

As shown in Fig. 33, the quarzuhi produces 458 pulses of curve 610, which in the entire multiplex and display system to its syn-

chronization can be used. The ring counter 46 (1 generates pulses of curves 612 and 614, which the output signals of the flip-flops Z18 and Z19 reproduce to form clock signals of reduced frequency. The negated signals ZT8 and ZI5

are represented by curves 616 and 620. The gates G 1 to G 4 generate high speed synchronization signals according to curves 621 to 624. It should be noted that the decoder 462 the output signals of the ring counter 460 are

since to form the pulse trains of the signals Gl to G 4, which are passed through the driver ^ 464 to form the clock signals I to IV. The signals Gl to G 4 are also ak synchronization

ntauf

: ise
ipied

'P-Si-
;in
tie
les
read

lie
: m
nd

ng
ch
: n,
en
: d.

!he ;in at en as ; m

; slie

Each-
Ie
al

ties
le

ir s i-I e

signals for the fast multiplexer are used to control its four switches. The clock signals G 29 to G 32 for the slow multiplexer are the signals clock I to clock IV, which are the negated signals G 1 to G 4 according to curves 628 to 631 .

In FIG. 34 the output signal of the element G 13 is shown as curve 634 . It is the negated form of the signal G 14 and defines the end of the blanking or jump back period of the elevation scanning according to curve 477, which is used for illustration. The reset pulses GI1 and G12 for the counter 472 are represented by curve 645, while the pulse G9 is represented by curve 647. The output signals of the elements G 29 to G 32, which are the signals clock I to clock IV, are illustrated by the curves 653 to 656. These are the control signals for the slow multiplexers which are fed to the flip-flop registers of the multiplexers, for example multiplexer 794 in FIG. 28. The control signals A to D according to curves 640 to 643 control the high-speed multiplexer. The high speed clock signal is represented by curve 659. The vertical signal G 15 is represented by curve 646 and the signal generated by element G 17 is represented by curve 648. The vertical blanking signal G 26, which is formed from the signals of the elements G 16 and G 17 and the clock signal C1, is shown by curve 650, while the vertical synchronization signal G 28 is shown by curve 652 d'.e.

Using the curves shown in FIG. 35, the devices for generating the clock signals will now be explained in more detail. The pulses of curve 660 form the square-wave signal with a frequency of 360 Hz, which is generated by the square-wave shaper 416 in FIG. 28 is delivered. After the reduction in the ratio 1: 8 in the divider 418, the antiphase driver signals for the synchronous detectors are generated by the push-pull driver 414, which are reproduced by the curves 662 and 664. The reference signal according to curve 666 is used by the modulator in the sensor unit.

In FIG. 36, curve 668 shows the horizontal directional signal which is used to synchronize the system for generating a horizontal blanking pulse according to curve 670 and an alternating pulse according to curve 672. The horizontal deflection signal used in the illustration is illustrated by curve 479 and is derived from a horizontal sync signal 655 obtained by delaying the horizontal directional signal on curve 668. The horizontal pulse is delayed in the directional delay circuit 492 in order to form the horizontal direction pulse according to curve 669.

On hand F i g. 37 the display system will now be explained in more detail. The display device contains a cathode ray tube 675, in front of whose screen 673 a suitable telescope or other magnifying device is arranged so that the image of the scanned scene reproduced on the screen can be conveniently viewed. The horizontal synchronization signal according to curve 655 is fed on line 513 to a horizontal oscillator 676, which can be a multivibrator which is designed so that its frequency sweep is slightly lower than the operating frequency during synchronization. The horizontal oscillator supplies pulses to a horizontal deflection generator 678 which has a linearly increasing signal Hefert which is applied to the horizontal deflection coil of the cathode ray tube 675. The vertical synchronization pulse according to curve 652 is fed on line 469 to a vertical oscillator 677, which can again be a multivibrator that supplies square-wave pulses for controlling a vertical deflection generator 679 . The alternating pulse according to curve 672 is fed on line 518 to the vertical deflection generator 679 in order to add the alternating signal necessary for the interlacing of the images to the control signal fed to the vertical deflection coil of the cathode ray tube. The video signal according to curve 690, which contains the data provided by the detectors at a predetermined frequency, is fed via line 482 to a video amplifier 692 which amplifies the multiplexed video signal to the level required to modulate the electron beam from the cathode ray tube. The video amplifier 692 can be, for example, a differential DC amplifier with a sensitivity of 2 V for black and white. One half of the output of the video amplifier 692 can be fed to the control grid and the other half can be fed to the cathode of the cathode ray tube 675. In some arrangements, the cathode signal can also be fed to the acceleration electrode via the power supply 682 in order to reduce defocusing of the cathode ray tube by signals of medium to high brightness. A brightness control signal is provided to video amplifier 692 from a source 695 in control panel 102 (FIG. 3) via line 104.

As can be seen from the schematic representation of the screen 673 in FIG. 38, the raster used comprises a certain number of horizontal lines which result from the multiplex processing and a certain number of vertical lines which result from the horizontal or azimuth scanning. The corresponding vertical and horizontal guidelines 698 and 700 are shown centered on the screen 673. An area delimited by dashed lines 701 is the display area in which the Narcissus effect would occur at a certain scanning angle if care had not been taken to erase the Narcissus image.

Fig. 39 finally illustrates the cooling system, which consists of two units, namely a helium compressor and a cooler, of which the cooler is part of the sensor unit. The helium compressor may include a compressor pump 714, a heat exchanger 716, a fan 718, and a line 720 that supplies helium to the cooling unit 726 through an oil separator 722 and an adsorber 724. The cooling unit can comprise an expansion valve and a suitable heat-conducting arrangement from which the gas is returned via a return line 730 to the compressor pump: 714. A structure 732 is disposed in the dewar near the detectors, as is known in the art. This type of cooling system is known and therefore does not need to be described individually.

Accordingly, a simplified and improved infrared viewing device has been described in which the detectors are nested and with the help of a flat mirror a horizontal scan of the field of view he follows. For the vertical direction, the detector signals are amplified and time-division multiplexed processed a single line of video signal, which is then played back in the display device. The display device includes a cathode ray tube that provides a visual representation of the received Provides infrared information in a grid that corresponds to a television grid. The grid is horizontally to the mechanical scanning by the mirror in the sensor unit and vertically to that through the electronic sampling generated by multiplexing is synchronized. Since both samples are timed linear and run in one direction, only one synchronization pulse is required for each scan. The system for the automatic regulation of the sensitivity leads into the optical devices a reference signal and enables individual and automatic control of the gain in

ίο every detector channel. By subsequent removal of the reference signal, an accurate and reliable representation can be obtained when viewing the scene is passively sampled.

In addition 24 sheets of drawings

Claims (10)

Patent claims: 1. Infrared viewing device with a telescope, a scanning mirror arranged on the image side of the telescope, which performs a scanning movement in a first direction, a detector group extending in a second direction perpendicular to the direction of the scanning movement, and a display device coupled to the detector group for generating an image of the scanned scene, which makes use of synchronization pulses and time-division multiplexed video signals, characterized in that a signal processor (82) is provided which has a device (122) for deriving the synchronization pulses directly from the scanning movement of the scanning mirror 122) and directly Multi-ao »lexer (380 ) coupled to the detector group 150) and working in real time for generating the video signals which the detectors of the detector group (150) scan one after the other in a specific sequence, each scan being characteristic of a data line in the second direction h and a certain number of data lines are recorded during each scan of the scene in the first direction, and that the display device (90) responds to the synchronization pulses and video signals generated by the signal processor (82). 2. Inf rarotsichtgei ät according to claim 1, characterized in that the first direction is the azitnut direction and the second direction is the elevation direction, that the signal processor (82) generate a horizontal synchronization pulse and the multiplexer (380) generate a vertical synchronization pulse, which is also fed to the display device (90). 3. Infrared viewing device according to claim 1 or 2, characterized in that the detector group 4 = (150) has a certain number of detector elements which are arranged in the vertical direction so that the detector elements define a vertical line in the display device, and that between the telescope (120 ) and the detector group (150) an alternating mirror (140) is arranged and an alternating signal source (496, 504) is provided which is coupled to the alternating mirror (140) and the display device (90) in order to bring about an alternating display of the vertical lines. 4. Infrared viewing device according to one of the preceding claims, characterized in that the signal processor (82) comprises a line of sight signal source which is coupled to the detector group (150) and serves to form a vertical line of sight in the display device (90), and that between Telescope (120) and detector group (150) a vertical directional mirror (136) is provided for adjusting the relative position of the detector group (150) in the vertical direction, which effects the adjustment of the vertical position of the vertical line of sight in the display device. 5. Infrared vision device according to e: inem of the preceding claims, characterized in that that the signal processor (82) comprises an adjustable horizontal line of sight signal source, which responds to the Hcrteontal synchronization pulse and with the Darstellunes ^ device (90) for Formation of a horizontal line of sight is coupled. 6. Infrared vision device according to one of the preceding claims, characterized in that it has a cold source on the detector group (150) , which causes the creation of a Narcissus image by reflection on optical members, and that between the telescope (120) and the detector group ( 150) a beam splitter (142) is arranged, to which energy is supplied from a Narcissus signal source (160) by which the effect of the Narcissus image is compensated. 7. Infrared vision device according to claim 6, characterized in that a modulator (168) is present, from which the beam splitter (142) is supplied with a modulated reference signal, and that the signal processor (82) has a device for gain control responsive to the reference signal. 8. Infrared vision device according to claim 7, characterized in that each detector of the detector group (150) is connected to the multiplexers (380) by its own, amplifier (376) containing channel, each of which is responsive to the reference signal. 9. Infrared vision device according to one of the preceding claims, characterized eek ^ nn ^ rfct ^ t. that the telescope (120) can optionally be adjusted to a wide or narrow field of view. 10. Infrared vision device according to claim 9, characterized in that for lenses ^ ¹ * "" ns telescope (120) from narrow to wide field of view in the beam path optical members (182) can be switched on.