DE2401267A1 - Infra-red thermal image system - uses mechanical scanning of scene and detector and light source arrangement - Google Patents

Abstract

The infrared thermal radiation is received by an objective and converted to visible radiation, which is superimposed on the scene image of an image amplifier. A rotary receiver head receives the thermal targest and emits the optical information of the visible radiation thus produced. The optical information is passed to the image amplifier by means of a fixed optical fibre line. The fixed mounting of the fibre line supports the abutment for the rotary receiver head. An auto-collimation mirror is arranged in front of the detector unit. The infrared objective and the optics of the fibre line are accommodated in the housing.

Description

Thermal imaging system, e.g. thermal direction finder with mechanical scanning of the visual image The invention relates to a thermal imaging system such as a thermal direction finder with mechanical Scanning the scene and a detector and light source arrangement, which is generated by a Objectively absorbed thermal radiation (IR) is converted into visible radiation and this superimposed on the scene image of an image intensifier.

A row of detectors is guided through the image of the scene and the electrical detector signal is further processed and, if necessary, via electrical Lines fed to the playback location Field of view can be searched for thermal targets, these possibly in an image intensifier viewing device be displayed in such a way that the location of the Heat target in the with the Image intensifier viewing device appears in the correct position. This requires a considerable amount of electronic elements and circuits, especially also for synchronization between scanning system and playback device.

The object of the invention is to find the correct position with less effort To achieve reproduction of a heat signal independent of the movement of the scan. This object is achieved in that a rotatable receiver head for recording the thermal targets and optical information delivery of the generated visible radiation and for forwarding the optical information to the image intensifier device at least a fixed-space optical fiber line are provided.

This achieves the following advantages: The correct position reproduction of the heat signal becomes inevitable regardless of the movement of the heat detector achieved.

Furthermore, the interfering device-specific thermal radiation received by the detector largely reduced.

The entire electronic signal processing is spatially united and can therefore be well shielded against external electromagnetic interference.

In addition, the number of expensive for processing thermal radiation necessary IR lenses are reduced to a minimum.

The drawing shows exemplary embodiments.

1 shows a thermal direction finder with spatially fixed IR optics, FIG. 2 shows optics that are moved together with the detector arrangement, FIG. 3 shows a schematic view Embodiment for the heat target reproduction in a light amplifier device.

According to Fig. 1, the thermal direction finder consists in principle of a housing 1, in which the IR lens 2, the imaging optics 3 at the input of an optical fiber line 4 made of glass fibers or the like.

whose initial part 4 'and a mechanical drive element 5 for the pivoting movement of the receiver head 10 mounted at 12 are fixed. The housing 1 is aligned with the scene. The in-line detector array 6 that Signalele 'ronilç 7 and the row-like arrangement of light sources 8 are together arranged with an autocollimation mirror 9 in the receiver head 10.

The receiver head 10, which receives the supply voltage via slip rings 13 is supplied, is mounted in the housing 1 so that the vertically aligned detector arrangement 6 is located in the image plane and executes a horizontal movement there.

The expedient Peltier-cooled row detector arrangement is moved together with d'Autokollimaticnsspiegel itself, so that the detectors the See scene strips one after the other. with appropriate storage and Movement of the receiver block can also have a vertical movement the detectors arranged in a horizontal row in this case will.

The autocollimation mirror 9 is expediently spherical Perforated mirror designed for the angle outside the current receiving angle produces autocollimation in a known manner. The imaging optics 3 forms a Light side of the moving light source arrangement 8 to the input of the fiber line 4 ', the other end of which the observer simultaneously with the light screen of an image intensifier tube can be viewed through a magnifying glass 14.

According to FIG. 3, there are basically two feed lines for the fiber line 4 alternatively possible, e.g. via a beam splitter prism 15 or via optics 16 to the cathode of the image amplifier 17.

The pivot point or the axis of rotation 10a of the receiver head 10 is expediently placed in the center of curvature of the generally curved image field. the Detectors of the detector arrangement 6 are optionally located on an arc of a circle to be arranged according to the radius of curvature. On a leveling of the field of view and the The use of complex IR optics can therefore be dispensed with.

The congruence of IR recording and playback becomes independent from the movement of the receiver head because the IR- (tjek -tiv'2 and the imaging optics 3 are arranged rigidly to one another and with the rigidly mounted housing are connected. The geometry of the light row of the light source arrangement 8 is correct with the geometry of the detector arrangement 6 in terms of absolute dimensions. In order to achieve this, a geometry-adapting arrangement may be provided in front of the light source arrangement 8 Arrange light guide (not shown in the figure). The storage of the recipient block 10 is therefore not critical. The receiver head 10 swings along about the bearing axis 10a low frequency (e.g. 1 Hz).

The movement is z.%. Magnets of the drive elements excited by electricity 5, which act in the horizontal direction, forced.

In the arrangement described, the IR optics are on the in general correct larger horizontal field of view angle.

The arrangement according to FIG. 2 basically contains the same elements like the arrangement according to FIG. 1 with the difference that the IR optics 2 'with the receiver head 10 forms a mechanical unit which is moved as a whole. The optical imaging system consists of a lens 3 'attached to the receiver head 10 and of that in the bearing piece 11 attached lens 3 in front of the fiber line end 4 '. The optical imaging system 3, 3 'and the fiber line end 4' are rigidly connected to the bearing piece 11, in which the receiver head 10 moves. Appropriately, the detectors are the Detector arrangement 6 to be arranged in the axis of rotation 10b in order to reduce the acceleration forces to keep it small. The light source arrangement 8, identical in its geometry to that Detector arrangement 6 is to be arranged outside the axis of rotation.

The bearing elements 12, slip rings 13 for the supply of the supply voltage to the receiver head 10 0 and the mechanical drive 5 are also in the bearing piece 11 housed. This arrangement is based on the generally smaller vertical Correct field of view angle.

Multiple image reproduction is also possible in both arrangements Attachment of several parallel operated light sources and corresponding imaging systems possible with optical fiber cables.

Combined thermal sighting and thermal imaging systems can also be implemented will. All that is needed is a high-resolution IR lens and a second row correspondingly smaller detectors.

Claims (9)

Patent claims: : / 1; IThermal imaging system, e.g. thermal direction finder, with mechanical scanning the scene and a detector and light source arrangement that is captured by a lens The absorbed thermal radiation (IR) is converted into visible radiation and this dem Scene image of an image intensifier, characterized in that a rotatable receiver head for receiving the heat targets and optical information output the generated visible radiation and for the transmission of the optical information at least one fixed optical fiber line is provided on the image intensifier device are. 2. Wärniobildsystein according to claim 1, characterized in that the spatially fixed holder of the fiber line (4) the counter bearing (12) for the rotatable Receiver head (10) carries an autocollimation mirror in front of the detector arrangement (6) (9) is arranged. 3 thermal imaging system according to claim 1 or 2, characterized in that, that the TR lens (2) of the receiver head (10) and the holder of the fiber line (4) are housed with their input optics (3) in a housing (1). 4. Thermal imaging system according to claim 1, characterized in that the Fiber line (4) in one as a counter bearing (12 ') for the receiver head (10) serving housing (11) is housed, and the input optics of the fiber line (4) from one attached to the housing (11) and from one attached to the receiver head (10) Lens (3, 3i) consists (Fig. 2). 5. Thermal imaging system according to claim 4, characterized in that the IR lens (2 ') is attached to the receiver head (10), and the one on the receiver head (10) attached lens (3 ') of the input optics and the light source arrangement (8) are outside the axis of rotation (10b) of the receiver head (10). 6. Thermal imaging system according to claim 1 or one of the following, characterized characterized in that a bupe (14) is provided at the exit of the fiber line (4). 7. Thermal imaging system according to claim 1 or one of the following, characterized characterized in that the thermal target information is applied to the cathode of the image intensifier device is fed. 8. Thermal imaging system according to claim 6, characterized in that the Would you? Ez elirformation about one. arranged in the output of the image intensifier device Beam splitter is fed. 9. Thermal imaging system according to claim 1 or one of the following, characterized characterized in that a controllable magnet for the pivoting movement mg of the receiver head is provided as a mechanical drive element (5).