DE3514380A1 - Afocal thermal imager - Google Patents

Abstract

The afocal thermal imager, which is constructed as an ancillary apparatus for an optical apparatus, for example a sight, has an image recording and reproduction part with an imaging ratio of 1:1, its optical axes being intended to be aligned parallel. The detector device 10 of the image recording part 3.1 has a detector which consists of at least one detector element, and the image reproduction part 3.2 has a display which consists of pixels which are arranged in the form of a matrix. At least one pixel is unambiguously allocated to each detector element, the allocation between in each case one detector element and one pixel being displaceable by defined steps in the line and/or column direction of the respective matrix. In consequence, the optical axes 5 and 15 of the image recording and reproduction parts 3.1 and 3.2 can be aligned parallel. <IMAGE>

Description

04/18/85, 0438Α ΖΤΤ8 Mn / bk

9726 Patent Department

Afocal thermal imaging device

The invention relates to an afocal, designed as an attachment for an optical device, e.g. a visor Thermal imaging device, with an imaging part in the infrared for generating electrical image signals, which has an input optics and a detector device, and having an image display part connected to the image pick-up part for generating an image in the visible from the electrical image signals and with output optics, with image recording / and playback part together have an aspect ratio of 1: 1 and their optical axes are aligned parallel are in particular according to patent P 33 38 496.

In the main patent P 33 38 496 is an afocal thermal imaging device described, in which the image display part has a cathode ray tube and an axis harmonization is made between image recording and reproducing part in that one on the screen Line mark of the image pickup part that appears as an image by electrically shifting the image in the cathode ray tube is brought to coincide with a line mark applied to the screen.

The operation of cathode ray tubes requires one relatively high electrical expenditure, so that other components will be preferred for image reproduction in the future. So-called displays come into question here, with increasing miniaturization of the individual picture elements (Pixels) have achieved a resolution that is sufficient for many purposes.

The object of the invention is to provide an afocal thermal imaging device of the type mentioned above, in which

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a problem-free axis harmonization is also possible when using a display in the image reproduction part.

This object is achieved by a thermal imaging device designed according to the characterizing features of claim 1 solved.

Provided that both the detector and the display are fixedly arranged within a housing exist between the detector elements and the pixels of the display due to the digital Electronic connection always has a clear assignment, which is in contrast to the use of cathode ray tubes also not changed by voltage fluctuations and the like. So it is sufficient to harmonize the axes from the image recording and playback part to a specific point in the area or on a separate board with the Aiming at the sight and then the image on the image reproduction part with the thermal imaging device connected upstream to move gradually until the same point appears again in the optical axis of the sight. With an aspect ratio of 1: 1, the optical axes of the image recording and reproducing device are then parallel. On separate line marks arranged in the image recording or reproduction part be waived.

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The invention is described in more detail below with reference to two exemplary embodiments, some of which are shown schematically.
Show it:

1 shows an afocal thermal imaging device with a detector array that captures the entire image;

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9726 Patent Department

2 shows an afocal thermal imaging device with a scanning device guiding the image via a detector.

In front of the exit opening of a visor 1 with a Directional mirror 2, a thermal imaging device 3 is arranged, which together with the visor or the directional mirror is rotatable so that the optical axis 4 of the visor 1 is always parallel to the axis 5 of the thermal imaging device. The thermal imaging device 3 consists of an image recording part 3.1 and an image reproduction part 3.2. The imaging part 3.1 according to FIG. 1 essentially has infrared optics 6 and 8 and a detector surface array 10. The from the individual detector elements of the detector surface array The charges generated 10 are stored in a charge displacement element designed as a pixel memory 7 (Charge-Coupled Device, CCD). The enrollment process is clock-controlled by a clock generation 16, which is controlled by an electronic synchronization unit 17 as well as by a manually operated clock 18 is controlled. The CCD line memory is also read out via a clock generator 19, which can be operated manually by the synchronization unit 17 and another Clock 20 is controlled.

The image is reproduced on an LED display 11, the image area of which via an output optics 13 as well a partially transparent corner mirror 14 is reflected into the beam path 4 of the visor 1. The optics 6, 8 and 13 are coordinated so that with the given area sizes of the detector 10 and the Displays 11 result in an aspect ratio of 1: 1.

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04/18/85, 0438A ZTT8 Mn / bk 9726

The optical axis 15 of the image display part is defined by the image element of the LED display, the lies on the optical axis 4 of the visor 1. For the parallel alignment of the optical axes 5 and 15 must exactly one detector element can be assigned to this picture element, in such a way that a mark 12, which is connected to the sight without a thermal imaging device, if the thermal imaging device was connected, it was exactly at the same point appears. This assignment and thus the axis harmonization between the image recording and playback device takes place by the manually operated clocks 18 and 20 in the χ and y directions. By the clock 18 is the reading of an image line into the shift register of the pixel memory 7 is offset in time, which is a shift corresponds to an image line in the x-direction to the left or right. With the manually operated clock generator 20, the reading out of an entire image line is offset in time, which results in a shift in the y-direction means above or below. In this way, the image 12 of the mark 12 can be viewed on the one defining the optical axis 15 Image element are shifted (12 "), so that with an aspect ratio of 1: 1 between image recording and playback device the axis harmonization is established.

In the embodiment shown in FIG. 2, instead of a large-area detector array, a single element or a detector line 10 'consisting of a few elements is used, which scans an image field by means of a scanning device 9 (scanner). The scanning device 9 essentially has two mutually perpendicular scanning directions in working ^, ¹ electrically controlled units 9.1 and 9.2. The radiation incident through the optics 6 and 8 first hits a height-deflecting mirror of the unit

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9.1, by means of a drive controlled by a control 21, a vertical pivoting movement with a given frequency. The radiation arrives from the unit 9.1 which effects the height deflection then on to horizontal scanning 9.2, which is essentially a mirror polygon, which rotates at high speed scans a horizontal line of images. The mirror polygon also has one electric drive and is controlled by a speed control 22. On the axis of the Mirror polygons sits a rotation angle sensor 9.3, whose Signals of an electronic synchronization unit 17 are fed.

The radiation deflected in this way then reaches the infrared detector 10 ', its electrical output signals written into a charge shifting element of a pixel memory 7 (charge-coupled device, CCD) will. The writing process is done clock-controlled by a clock generator 23, which is from the electronic synchronization unit 17, as well as controlled by a manually operated clock generator 24 will. The CCD line memory is read out in a synchronized manner by the synchronization unit 17. The signals read out are then shown on an LED display 11, analogous to that shown in FIG Embodiment supplied.

The axis harmonization between the image recording and playback part takes place, as in the first exemplary embodiment, by means of an external mark 12, its image 12 'is again shifted on the LED display until it is exactly on the optical axis 4 of the visor 1 is (12 "). The shift in the line direction (x-direction) takes place analogously to that in FIG

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04/18/85, 0438Ά ΖΤΤβ Mn / bk 9726

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Embodiment described in that the reading of an image line in the shift register of the pixel memory 7 is shifted in time by the clock 24, which is a shift of an image line corresponds to left or right. The vertical displacement takes place in that the alternating current control signal of the controller 21 for the height deflection mirror the unit 9.1 a DC voltage signal from the manually operable transmitter 25 is added or subtracted therefrom. This will make the center position of the Height deflection mirror and thus the optical axis adjusted in height. The adjustment is advantageously carried out in defined steps that correspond exactly to a line spacing.

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Claims (3)

Claims 1. Afocal, as an attachment for an optical device, e.g. 8. a visor, trained thermal imaging device, with an image recording part in the infrared for generating electrical Elldsignale, which an input optics and having a detector device, and having an image display part connected to the image pick-up part to generate an image in the visible from the electrical Image signals as well as with an output optics, with image recording and playback part together Have an aspect ratio of 1: 1 and their optical axes are aligned parallel, especially after Patent P 33 38 496, characterized by the following features: a) the detector device (10, 10) of the image recording part (3.1) has a detector consisting of at least one detector element, _% b) the image reproduction part (3.2) has a display consisting of image elements arranged in a matrix (11) on, c) at least one picture element is uniquely assigned to each detector element and e) the assignment between one detector element and each a picture element is to be defined in steps Row and / or column direction of the respective matrix can be displaced in such a way that the optical Axes (5 and 15) of the image capturing and reproducing part (3.1 and 3.2) are parallel. 35H380 MBB Patent department 04/18/85, 0438A ZTT8 Mn / bk 9726 10 2. Afocal thermal imaging device according to claim 1, characterized in that the Detector device (10) has a detector array capturing the entire image and each Detector element via an image point memory (7) each one image element of the image reproduction part (3.2) is assigned and that by shifting the pixels in the pixel memory (7) the assignment to the picture elements of the picture display part (3.2) can be changed. 3. Afocal thermal imaging device according to claim 1, characterized in that the image recording part (3.1) one, the image line by line a detector (10) consisting of one or more detector elements leading scanning device (9) comprises that the image generated in this way on the detector (10 *) is stored in a pixel memory (7) and that by shifting the pixels the assignment to the picture elements of the picture display part (3.2) can be changed in the picture element memory (7) is. 25th 30th 35