WO2005114987A1

WO2005114987A1 - Device for detecting an object scene

Info

Publication number: WO2005114987A1
Application number: PCT/EP2005/005115
Authority: WO
Inventors: Hans Dieter Tholl; Rainer Baumann; Joachim Barenz
Original assignee: Diehl Bgt Defence Gmbh & Co. Kg
Priority date: 2004-05-22
Filing date: 2005-05-12
Publication date: 2005-12-01

Abstract

The invention relates to a device (112) for detecting an object scene. Said device comprises an imaging optical system (120) and at least three detectors (114, 116, 118), optically linked with the optical system (120). The inventive device is characterized by an optical branching (2, 32, 52, 62, 82, 96, 150) having a compact prism array with a number of prisms (4, 6, 8, 10, 34, 36, 38, 40, 54, 56, 58, 60, 64, 66, 68, 70, 72), a first, a second and a third outer beam passage surface (88, 90, 92, 94) and a partially reflecting layer (24, 44, 48, 76, 84, 98) that optically links the first beam passage surface (88) with the second and third beam passage surface (90, 92, 94). The prism array comprises a second partially reflecting layer (26, 46, 50, 78, 86, 100, 102, 104) that is aligned at an angle to the first partially reflecting layer (24, 44, 48, 76, 84, 98). The optical system (120) has a first stationary part (124) and a mobile part (122) that can be swiveled in relation to the first part (124) by at least one axis (132, 136). The optical branching (2, 32, 52, 62, 82, 96, 150) is mounted in the stationary part (124) of the optical system (120). The inventive device allows to detect a large solid angle and is very compact.

Description

Device for capturing an object scene

The invention is based on a device for detecting an object scene with an imaging optical system and at least three detectors connected to the optical system.

With such a device, at least three independent pieces of information from the object scene can be evaluated. Such devices are known for example from US 3,333,053 or from US 3,610,818. The known devices are structurally large. To observe large solid angles, the devices as a whole have to be pivoted disadvantageously, since the individual components are arranged rigidly to one another.

The object of the invention is to provide a device of the type mentioned at the outset which is structurally small and with which unproblematicly large solid angles can be observed.

This object is achieved according to the invention by a device of the type mentioned at the outset in that a) an optical branch is provided with a compact prism arrangement which has a number of prisms, a first, a second and a third outer beam passage surface and a partially reflecting layer which optically connects the first beam passage area to the second and third beam passage area, the prism arrangement having a second comprises partially reflective layer, which is oriented at an angle to the first partially reflective layer, that b) the optical system comprises a first structurally fixed part and a movable part which is pivotable relative to the first part about at least one axis, and that c) the optical branching in the structurally fixed Part of the optical system is arranged.

Optical branching as such is known in particular in the form of a beam splitter cube, which consists of two prisms in the form of a cube half each, which are connected to one another along a cube diagonal surface. A partially reflecting layer in the form of a dichroic interference filter can be attached to one of the facing cube diagonal surfaces. To separate several spectral ranges, several beam splitter cubes are optically connected in series. In addition, a second partially reflective layer is included, which is oriented at an angle to the first partially reflective layer. Radiation passing through a beam passage area can be led out of the prism arrangement in three different directions, as a result of which there is no need to cascade optical branches.

The optical system comprises a first structurally fixed part and a movable part which can be pivoted about at least one axis relative to the first part. A particularly small and mechanically stable device is achieved in that the optical branch is arranged in the structurally fixed part of the optical system. A large angle of the object scene can be captured. In addition, the detectors can remain focused on the object scene during a movement of the structurally fixed part relative to the object scene by a compensating movement of the movable part. The optical branching and detectors provided for detection need not be moved.

The device is particularly suitable for a missile for detecting targets. The structurally fixed part is particularly direct or indirect firmly connected to an outer shell of the missile. The movable part is expediently arranged within a window dome of the missile.

The partially reflecting layer is advantageously tilted by approximately 45 ° ± 5 ° to the optical axis of the system and expediently arranged in the parallel beam path in order to avoid asymmetrical, uncorrectable astigmatism.

A large solid angle can be detected by the device, the pivotable part of which is oriented at least two perpendicular to one another

Axes is pivotable. In particular, the movable part comprises a first part which is arranged in a holding device pivotable about the first axis and a second part which is arranged in a holding device pivotable about the second axis. The holding device is, for example, a frame.

The prism arrangement is compact and thus free of a gas-filled cavity at least in the beam path. It comprises outer beam passage surfaces, which can optionally be coated and can limit the prism arrangement to the outside. To minimize the reflection losses at the

Beam passage areas are expediently coated with an antireflection coating. The partially reflecting layers can be arranged between mutually facing surfaces of the prisms and can, for example, form a low pass or a high pass which allows radiation to pass below or above a frequency limit. It is also possible to design a partially reflecting layer as a bandpass filter, which reflects a partial spectral range of the incident radiation with high effectiveness and transmits the remaining partial spectral range with high effectiveness. The prisms have a high transmission for the entire spectral range.

The partially reflecting layers are arranged at an angle to one another and are therefore neither parallel nor antiparallel, but at an angle of in particular over 10 ° to one another. Two or more of the same kind, not in one Layer-produced partially reflective layers which are aligned in the prism arrangement and which are provided for illumination through a single beam passage area can be regarded as a single partially reflective layer. An optical connection between two beam passage areas is established by guiding radiation passing through a beam passage area into the other beam passage area with the aid of a partially reflecting layer. The steering preferably takes place in such a way that radiation entering perpendicularly through a beam passage area is directed through a partially reflecting layer to the other beam passage area in such a way that it strikes this beam passage area perpendicularly.

The invention encompasses the use of the optical branching as a beam splitter, one of the beam passage areas being configured as a beam entry area and the other two beam passage areas being configured as first and second beam exit areas, and the partially reflecting layer comprising a first part of the radiation entering the first beam exit area and a second Part of the radiation entering through the beam entry surface directs into the second beam exit surface. The second partially reflecting layer directs a third part of the radiation entering through the beam entry surface into a third beam exit surface. With the same advantage, the invention comprises an optical branching, which is used as a beam connector, the first partially reflecting layer guiding radiation entering the prism arrangement through two different beam passage areas into the third beam passing area designed as a beam exit area and the second partially reflecting layer through a further one

Beam passage area in the prism arrangement also directs radiation into the beam exit area.

At a larger angle of the partially reflecting layers to one another, in particular at a right angle, the partially reflecting layers are inclined, in particular tilted by 45 °, to the optical axis of the beam path. , According to the Fresnef formulas, an air gap would result in high reflection losses. The prisms are therefore advantageously firmly connected to one another, advantageously by means of a suitable adhesive, for example an optical putty. The refractive index of the adhesive must be close to that of the prism material to prevent reflection losses. Furthermore, the adhesive must have a high transmission, that is to say a vanishing absorption, for the spectral range in transmission, in particular for the entire spectral range. Both the adhesive layer and the partially reflecting layers are advantageously very thin, for example 10 μm to 20 μm, so that neither the adhesive nor the interference layer system in transmission cause any significant asymmetrical aberration.

A small optical branching can be achieved in that the partially reflecting layers are each arranged in one plane, the planes interpenetrating one another within the prism arrangement. The compact prism arrangement is expediently cube-shaped. An optical branching which is particularly small in terms of installation space and has a sufficient number of beam passage areas can be achieved.

In a further embodiment of the invention, the partially reflecting layers are arranged perpendicular to one another. An effective reflection and an orthogonal beam path can be achieved, which is particularly advantageous in a prism arrangement designed as a cube.

The partially reflecting layers are advantageously each designed as a dichroic filter, in particular as an interference layer system. It is possible to selectively separate and investigate frequency bands from the entire incident spectrum and, for example, each as a dielectric one

Interference layer system can be formed. Such an interference layer system comprises up to 100 preferably between 10 and 25 evaporated dielectric layers made of alternately arranged different materials with different refractive indices.

In a further embodiment of the invention, at least one partially reflecting layer comprises a polarization filter. Information about the polarization of the incident radiation, in particular in addition to spectral information, can be evaluated. A comprising the polarization filter Partially reflecting layer can be designed such that a part of the incident radiation which is polarized in a certain direction is reflected and the rest of the radiation is transmitted. In addition to the polarization filter, the partially reflecting layer can additionally comprise a spectral filter of a desired type. It is also possible that the polarization filter alone is the essential optical

Property of the partially reflecting layer. The optical branching expediently comprises at least one partially reflecting layer with a polarization filter and at least one partially reflecting layer with a spectral filter. Spectral information and polarization information can be obtained simultaneously.

A selective filtering out of desired properties of the radiation can be achieved if one partially reflecting layer is transparent to radiation reflecting on the other partially reflecting layer. The layers do not influence each other and allow the information obtained to be easily evaluated.

A particularly simple configuration of the optical branching, which is small and inexpensive in terms of installation space, can be achieved if the prisms are four prisms assembled into a cuboid, each with a hypotenuse surface, two

Catheter surfaces and two mutually parallel side surfaces are. The cuboid is especially a cube.

A further advantage of the invention is achieved if one of the prisms forms a beam passage area with its hypotenuse surface and the first

The catheter surface of the prism is coated with a first partially reflective layer and the second catheter surface of the prism is coated with a second partially reflective layer that is different from the first. The radiation reflected by the partially reflecting layers only crosses an adhesive layer between the prisms, as a result of which a high intensity of the reflected radiation can be achieved. A particularly cost-effective production of the prism arrangement can be achieved if one of the catheter surfaces of the prisms is coated with a partially reflective layer.

Further spectral information or information on the polarization of the in the

Radiation incident on the prism arrangement can be obtained if the prism arrangement comprises at least a third partially reflecting layer, which is angled to the first and second partially reflecting layers. The third partially reflecting layer advantageously directs radiation incident in the third layer into a fourth beam passage area. The third partially reflecting layer is expediently arranged in a plane which, within the prism arrangement, penetrates the planes of the first and second partially reflecting layer likewise arranged in one plane. When using the optical branching as a beam splitter, the third partially reflecting layer can convert part of the radiation incident into it into a third

Steer the beam exit surface.

Four pieces of information, in particular five pieces of information on the incident radiation, can be evaluated separately if the prism arrangement has a cube shape, an outer surface of the cube being

Serves beam entrance surface and at least four of the remaining five outer surfaces each serve as a beam exit surface.

The invention is not restricted to cuboid or cube-shaped prism arrangements, but can be implemented in any form that appears advantageous to the person skilled in the art. The Platonic solids, which are composed of the same polygons, represent particularly favorable shapes. For example, the prism arrangement can be designed as a pentagon dodecahedron with twelve beam passage areas each in the form of an equilateral pentagon. One or more beam passage areas can be used as the beam entry area and one or more beam passage areas as the beam exit area. Complex beam paths and information distributions can be realized in the most compact form. A beam splitter cube whose entrance surface is perpendicular to the optical axis has the advantage that it only produces a rotationally symmetrical aberration, in particular a color error, which can be easily corrected by preceding or following lenses. The beam splitter cube can therefore be used in the parallel, convergent or divergent beam path. The

Beam splitter cubes also have the advantage over other beam splitting means that they take up little space in the device, since all beam incidence angles in the optical material of the beam splitter cube are reduced by the refractive index factor 1 / n. The beam splitting means is preferably a dichroic beam splitter cube. Such a beam splitter cube has spectrally generating ones compared to others

Beam splitter means the advantage of simple manufacture and great mechanical resilience.

drawing

Further advantages result from the following description of the drawing. Exemplary embodiments of the invention are shown in the drawing. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

Show it:

1 shows an optical branch configured as a cube with four prisms and two partially reflecting layers, FIG. 2 shows an optical branch with another arrangement of two partially reflecting layers, FIG. 3 shows an optical branch with a further arrangement of two partially reflecting layers, FIG. 4 an optical branching with five prisms, FIG. 5 an arrangement as in FIG. 1 with a polarizing and a spectral partially reflecting layer, FIG. 6 an optical branching designed as a cube with four partially reflecting layers angled to one another and FIG. 7 a device for detecting an object scene with a cube-shaped beam splitter.

In the figures 1 to 6 embodiments of the optical branching are shown as they are suitable for use in a device of the type mentioned.

FIG. 1 shows an optical branch 2 with a compact prism arrangement comprising four prisms 4, 6, 8, 10. The prisms 4, 6, 8, 10 are made of

Calcium fluoride manufactured, which is transmissive in a spectral range of λ = 0.2 μm - 9.0 μm. They have a triangular cross section and each include a hypotenuse surface 12, 14, 16, 18, which each serves as a beam passage surface. In the example of use shown in FIG. 1 the optical junction 2 as a beam splitter, the hypotenuse surface 18 serves as a beam entry surface, and the hypotenuse surfaces 12, 14, 16 each serve as a beam exit surface. Without changing the arrangement, it is also possible to radiate into the hypotenuse surfaces 12, 14, 16 and to use the hypotenuse surface 18 as the beam exit surface, that is to say the optical branching 2 as

Beam connector to use. The hypotenuse surfaces 12, 14, 16, 18 are each provided with an anti-reflection coating, not shown, in order to keep reflection losses as low as possible when radiation enters and exits the hypotenuse surface 18 or from the hypotenuse surfaces 12, 14, 16.

The four prisms 4, 6, 8, 10, which when put together result in a compact, cube-shaped prism arrangement, each have two catheter surfaces 20, 22, of which only the two catheter surfaces 20, 22 of the prism 10 are provided with reference symbols for the sake of clarity. The catheter surface 20 of the prism

10 is coated with a first partially reflecting layer 24, which is designed as a dichroic layer from a 15 μm thick interference layer system. This first partially reflecting layer 24 continues on a catheter surface of the prism 8, so that the first partially reflecting layer 24 is arranged essentially completely on a cube diagonal of the optical branch 2. A second partially reflecting layer 26, which is also a dichroic interference layer system, is applied to the second catheter surface 22 of the prism 10. The second partially reflecting layer 26 is also continued on a catheter surface of the prism 4, so that the second partially reflecting layer 26 is also essentially completely on one

Cube diagonal surface of the optical branch 2 is arranged. The partially reflecting layers 24, 26 are arranged between mutually facing catheter surfaces of the prisms 4, 6, 8, 10.

The two partially reflecting layers 24, 26 are oriented at an angle of 90 ° to one another, so that part of the radiation incident perpendicularly into the hypotenuse surface 18 is directed through the two partially reflecting layers 24, 26 in each case perpendicular to the hypotenuse surfaces 12 and 16, respectively. The rest Radiation radiates essentially freely into the hypotenuse surface 14 of the prism 6.

The four prisms 4, 6, 8, 10 are each connected to the cube-shaped compact prism arrangement by a thin adhesive layer 28, the adhesive of the adhesive layer 28 being transmissive for infrared radiation. To prevent reflection losses, the refractive index of the adhesive is close to the refractive index of the material of the prisms 4, 6, 8, 10. The partially reflecting layers 24, 26 and the adhesive layer 28 are shown much thicker for clarity than between them

Prisms 4, 6, 8, 10 are applied. The adhesive layer 28 and the partially reflecting layers 24, 26 are tilted by 45 ° to the optical axis of the incident radiation from all hypotenuse surfaces 12, 14, 16, 18. The first partially reflecting layer 24 thus optically connects the hypotenuse surface 18 to the hypotenuse surfaces 14, 16, and the second partially reflecting layer

26 connects the hypotenuse surface 18 to the hypotenuse surfaces 12, 14.

The first partially reflecting layer 24 is manufactured in such a way that it reflects radiation in a frequency band between 1 μm and 1.5 μm and transmits infrared radiation in another frequency range essentially unimpeded. The second partially reflecting layer 26 reflects a frequency band between 3.5 μm and 4 μm essentially completely and transmits other infrared radiation.

When infrared light is irradiated in a wavelength range that is in

1 is denoted by λ, the hypotenuse surface 18 reflects infrared light in the spectral range λi = 1 μm to 1.5 μm from the first partially reflecting layer 24 and directs it to the hypotenuse surface 16, which serves as the beam exit surface of the optical branch 2. The second partially reflecting layer 26 reflects infrared radiation with λ ₂ = 3.5 μm to 4 μm and directs it to the hypotenuse surface 12 of the prism 4. The remaining infrared radiation in the wave range λ, which is not within the two frequency bands λi and λ ₂ , becomes transmitted by both partially reflecting layers 24, 26 and leaves the optical branch 2 through the hypotenuse surface 14 of the prism 6. This residual spectral range is designated λR.

FIG. 2 shows a further optical branch 32 with four prisms 34, 36, 38, 40, which together form a compact cube-shaped prism arrangement. Analogously to the optical branching 2 shown in FIG. 1, the prisms 34, 36, 38, 40 are connected to one another with an adhesive layer 42 and provided with a partially reflecting layer 44, 46 from a dichroic interference system on only one of their cathetus surfaces. In this way, inexpensive production of the partially reflecting layers 44, 46 can be achieved.

Except for the different arrangements of the partially reflecting layers 44, 46 on the prisms 34, 36, 38, 40, the optical branch 32 corresponds to the optical branch 2.

Another possibility of coating two partially reflecting layers

48, 50 in an optical branch 52 designed as a beam splitter cube is shown in FIG. Here, two prisms 54, 56 are uncoated on their catheter surfaces and two prisms 58, 60 each have a part of the partially reflecting layers 48, 50 on both catheter surfaces.

A somewhat different arrangement of an optical branch 62 is shown in FIG. As in the previous figures, the optical branching 62 is designed as a trichroic beam splitter cube, which in this case, however, comprises four rectangular prisms 64, 66, 68, 70 and a rectangular prism 72. Around the cuboid prism 72, the prisms 64, 66, 68, 70 are glued to their hypotenuse surface with a thin adhesive layer 74. The beam passage areas of the optical branch 62 are each formed by cathetic areas of the prisms 64, 66, 68, 70. A thin dichroic interference layer system is applied to the hypotenuse surfaces of the prisms 64, 66, 68, 70, the dichroic layer applied to the prisms 64, 68 forming a first partially reflecting layer 76 and the dichroic layer applied to the prisms 66, 70 forms a second partially reflective layer 78. Both partially reflecting layers 76, 78 thus consist of two partial layers, each parallel to one another are aligned and are illuminated by radiation which passes through a beam passage area of the optical branch 62.

Another embodiment of the invention is shown in FIG. 5. FIG. 5 shows an optical branching 82 designed as a beam splitter cube, which in FIG

The difference between the optical branch 82 and the optical branch 2 is that the first partially reflecting layer 84 is a polarization layer which reflects radiation oscillating perpendicular to the plane of the paper and radiation oscillating parallel to the plane of the paper transmitted. A second partially reflecting layer 86 of the optical branching 2 is designed as a low-pass filter, which allows radiation between 5 μm and 10 μm to pass through and reflects radiation with a wavelength between 1 μm and 5 μm.

When infrared radiation in the spectral range λ is irradiated by the

Beam passage area 88, the portion of radiation oscillating parallel to the paper plane in a second frequency band λ = 5 μm-10 μm is neither reflected by the polarization filter of the first partially reflecting layer 84 nor by the spectral filter of the second partially reflecting layer 86. This radiation component passes through the optical branch 82 essentially unhindered and exits the optical branch 82 through the beam passage area 90. The portion of radiation in the second frequency band λ _{2 which} vibrates perpendicular to the paper plane is reflected by the first partially reflecting layer 84 and leaves the optical branching 82 through the beam passage area 92. A portion which is oscillating in the paper plane in a first frequency band λ _\ = 1 μm - 5 μm becomes only reflects and leaves the optical branching 82 through the second partially reflecting layer 86 by emerging vertically through a beam passage area 94. The portion of radiation in the first frequency band λi which vibrates perpendicularly to the plane of the paper is reflected by both partially reflecting layers 84, 86 and leaves the optical branch 82 through the same beam passage area 88 in which it is radiated into the optical branch 82. FIG. 6 shows an optical branch 96 designed as a pentachroic beam splitter cube with 14 prisms made of, for example, zinc sulfide cleartran, which have a high transmission for radiation in the spectral range λ = 0.4 μm-14 μm. (Cleartran is a registered trademark of the Rohm & Haas Company, Wobum, MA 01801, USA.) The prisms have four partially reflective layers

98, 100, 102, 104. The first partially reflecting layer 98 and the second partially reflecting layer 100 are designed analogously to the partially reflecting layers 24, 26 of the optical branching 2 from FIG. 1. The third and fourth partially reflecting layers 102, 104 are each parallel to two further cube diagonals arranged so that all four partially reflecting layers 98,

100, 102, 104 are arranged at an angle of 45 ° to a beam entry surface 106 of the optical branch 96. Four frequency bands λi, λ ₂ , λ ₃ , λ are cut out from radiation of the spectral range λ, which enters the optical branching 96 through the beam entry surface 106, through the partially reflecting layers 98, 100, 102, 104, and a residual spectral range λ leaves the optical one Branch 96 is essentially unimpeded on the beam exit surface of the optical branch 96 opposite the beam entry surface 106. It is also possible to provide only three partially reflecting layers or only two partially reflecting layers which are not perpendicular to one another

Cube diagonals are arranged.

The optical branching 96 comprises two pyramid-shaped prisms, the square base surface of which forms the beam entry surface 106 or the invisible beam exit surface for radiation of the residual spectral range λ _R. Furthermore, the optical branch 96 comprises eight four-surface prisms and four six-surface prisms, so that the optical branch 96 consists of 14 prisms which are joined together by an adhesive layer 108 to form a compact prism arrangement.

FIG. 7 shows a device 112 for detecting an object scene, which comprises three optical detectors 114, 116, 118 and an optical system 120 which consists of two parts 122, 124. The device 112 is arranged in a shell 126 of a missile. The nose of the missile is from a hemispherical Cathedral or window 128 formed. The device 112 has a rolling frame 130 which is rotatably mounted about a rolling axis 132. The roll axis 132 coincides with the longitudinal axis of the missile. A pitch frame 134 is pivotally mounted in the rolling frame 132 about a pitch axis 136. The rolling frame 130 allows the pitch frame 134 to pivot about the pitch axis

136 through an angle of approximately 180 °.

A telescopic lens 138 is attached to the pitch frame 134 and can be pivoted into a hemisphere-sized solid angle. A first deflecting prism 140 for deflecting the optical axis is also attached to the pitch frame 134

142, which coincides with the roll axis 132 in the region of the telescope optics 138, into the pitch axis 136. The hypotenuse surface of the deflection prism 140 forms an angle of 45 ° with the optical axis 142. The entry catheter surface of the deflection prism 140 can be convex and the exit catheter surface of the deflection prism 140 can be concave, so that the deflection prism 140 is one

Has lens effect. In this way, an intermediate image of the object scene can be achieved between the deflection prism 140 and a second deflection prism 144. The use of the deflection prism 140 as a lens reduces the number of reflecting surfaces and thus light losses due to scattered light. Furthermore, through a clever choice of materials and refractive index of the deflection prisms 140,

144, 146, 148 the optical system 120 are passively temperature compensated.

Two deflection prisms 146, 148 are held in the rolling frame 130, which deflect the optical axis 142 first parallel to the rolling axis 132, then parallel to the pitch axis 136 and then into the rolling axis 132. The second deflection prism 144 sits on the

Pitch axis 136. Its hypotenuse surface is inclined by 45 ° to the pitch axis 136 and to the optical axis 142, once deflected. The catheter surfaces of the deflection prism 144 can be configured analogously to the catheter surfaces of the deflection prism 140, so that an intermediate image is arranged between the second deflection prism 144 and the third deflection prism 146 and in an analogous manner between the third deflection prism 146 and the fourth deflection prism 148. The hypotenuse surfaces of the deflection prisms 146, 148 are in turn inclined by 45 ° to the optical axis 142, so that the Imaging beam path from the telescope optics 138 is directed into an optical branch 150.

In the optical branch 150, the radiation of the imaging beam path is divided into two frequency bands and a residual spectral range, as described for FIG. 1. The radiation in a frequency band which is between 0.4 μm and 0.8 μm in visible light is fed to the detector 114, which is sensitive in this frequency band. Radiation from the second frequency band, which is in the near infrared between 0.8 μm and 1.5 μm, is fed to the detector 118. The detector 118 is sensitive in the near infrared between 1.5 μm and 1.6 μm, this second spectral path serving to receive active LADAR radiation, which in particular also provides the exact object distances. The main path in transmission through the optical branching 150 is provided for the infrared spectral range between 2 and 5 μm, which also enables a passive detection of an object scene

Allows night and bad weather.

In FIG. 7, the optical branch 150 is arranged in front of lenses of a detector objective 152 of the spectral path in transmission. Here, the two other spectral paths in reflection have their own detector objective 154, 156. It is also possible to arrange the optical branch 150 between or after detector objectives 152, 154, 156, whereby the number of lenses can be reduced, but a chromatic one for a wide overall spectrum Aberration is not easy to correct.

Instead of the optical branching 150 configured as a beam splitter cube, other of the optical branching 32, 52, 62, 82, 96 described above can also be used in the device 112. Other optical branches, such as beam splitter plates or beam splitter membranes, are also possible. The beam splitter plates should be tilted 45 ° to the optical axis 142 of the optical system 120. The invention related to the device relates to any optical branching that splits a beam path in two or more directions or combines two or more incident beam paths into one outgoing beam path. A beam splitter cube as an optical branch 150, the beam entry surface of which is perpendicular to the optical axis 142, has the advantage that it only produces a rotationally symmetrical aberration, in particular a color error, which can be easily corrected by modifying the preceding or following lenses. A beam splitter cube can therefore be used in the parallel, convergent or divergent beam path. A beam splitter cube also has the advantage over the beam splitter plate or a beam splitter membrane that it takes up much less space in the device 112, since all the beam incidence angles in the optical material are around the

Refractive index factor 1 / n can be reduced.

The optical branching 150 forms, together with the detector objectives 152, 154, 156, the structurally fixed part 124 of the optical system 120. The structurally fixed part 124 is fixedly held in the shell 126 of the missile. The part 122 of the optical system 120 is movably mounted relative to this structurally fixed part 124, a first part being fixedly connected to the rolling frame 130 and thus being one-dimensionally movable about the rolling axis 132 and a second part being fastened to the pitch frame 134 and being two-dimensionally movable , namely about the roll axis 132 and about the pitch axis 136.

The arrangement of the optical branching 150 in the structurally fixed optical part 124 has the advantage that a beam splitting takes place only in a structurally fixed manner, whereby space, material and thus costs can be saved.

reference numeral

2 branching 60 prism

4 prism 62 optical branching

6 prism 64 prism

8 prism 66 prism

10 prism 68 prism

12. Hypotenuse surface 70 prism

14 Hypotenuse surface 72 prism

16 Hypotenuse surface 74 adhesive layer

18 hypotenuse surface 76 layer

20 catheter surface 78 layer

22 catheter surface 82 branching

24 layer 84 layer

26 shift 86 shift

28 adhesive layer 88 beam passage area

32 optical branching 90 beam passage area

34 Prisma 92 S steel passage area

36 Prism 94 Beam passage area

38 prism 96 branching

40 prism 98 layer

42 adhesive layer 100 layer

44 layer 102 layer

46 layer 104 layer

48 Layer 106 beam entry area

50 layer 108 adhesive layer

52 optical branching 112 device

54 prism 114 detector

56 prism 116 detector

58 prism 118 detector 120 System 146 deflection prism

122 part 148 deflection prism

124 part 150 branching

126 Envelope 152 Detector objective

128 windows 154 detector lens

130 rolling frame 156 detector objective

132 roll axis λ spectral range

134 pitch frame λi frequency band

136 pitch axis λ ₂ frequency band

138 Telescope optics λ ₃ frequency band

140 deflection prism λ frequency band

142 optical axis λR residual spectral range

144 deflection prism

Claims

claims

1. Device (112) for detecting an object scene with an imaging optical system (120) and at least three detectors (114, 116, 118) optically connected to the optical system (120), characterized by a) an optical branching (2, 32, 52 , 62, 82, 96, 150) with a compact prism arrangement that has a number of prisms (4, 6, 8, 10, 34, 36, 38, 40, 54, 56, 58, 60, 64, 66, 68, 70, 72), a first, a second and a third outer beam passage area (88, 90, 92, 94) and a partially reflecting layer (24, 44, 48, 76, 84, 98) which has the first beam passage area (88) optically connects to the second and third beam passage surface (90, 92, 94), the prism arrangement comprising a second partially reflecting layer (26, 46, 50, 78, 86, 100, 102, 104) which is angled to the first partially reflecting layer (24 , 44, 48, 76, 84, 98), wherein b) the optical system (120) has a first structurally fixed part (124) and a movable part (122) which is pivotable relative to the first part (124) about at least one axis (132, 136), and wherein c) the optical branching (2, 32, 52, 62, 82, 96, 150 ) is arranged in the structurally fixed part (124) of the optical system (120).

Device (112) according to claims 1, characterized in that the pivotable part (122) is pivotable about at least two axes (132, 136) aligned perpendicular to one another.

3. Device (112) according to claim 1 or 2, characterized in that the partially reflecting layers (24, 26, 44, 46, 48, 50, 76, 78, 84, 86, 98, 100, 102, 104) each in one Are arranged in a plane, the planes mutually penetrating within the prism arrangement.

4. Device (112) according to one of claims 1 to 3, characterized in that the partially reflecting layers (24, 26, 44, 46, 48, 50, 76, 78, 84, 86, 98, 100, 102, 104) perpendicular are arranged to each other.

5. Device (112) according to one of the preceding claims, characterized in that the partially reflecting layers (24, 26, 44, 46, 48, 50, 76, 78, 84, 86, 98, 100, 102, 104) each as dichroic Filters, in particular as an interference layer system, are configured.

6. The device (112) according to one of the preceding claims, which comprises at least one partially reflective layer (84) comprising a polarization filter.

7. Device (112) according to one of the preceding claims, characterized in that the one partially reflective layer (24, 26, 44, 46, 48, 50, 76, 78, 98, 100, 102, 104) for on the other partially reflective layer (24, 26, 44, 46, 48, 50, 76, 78, 98, 100, 102, 104) reflected radiation is transparent.

8. Device (112) according to one of the preceding claims, characterized in that the prisms (4, 6, 8, 10, 34, 36, 38, 40, 54, 56, 58, 60) four prisms (4 , 6, 8, 10, 34, 36, 38, 40, 54, 56, 58, 60) each with a hypotenuse surface (12, 14, 16, 18), two Katletenflächen (20, 22) and two mutually parallel side surfaces ,

9. The device (112) according to claim 8, characterized in that one of the prisms (10, 58) with its hypotenuse surface (12) forms a beam passage surface and the first catheter surface (20) of the prism (10, 58) with a first partially reflecting layer ( 24, 48, 84, 98, 102) and the second catheter surface (22) of the prism (10, 58) is coated with a second partially reflecting layer (26, 50, 86, 100, 104) that is different from the first.

10. The device (112) according to claim 8, which also has one of the catheter surfaces of the prisms (34, 36, 38, 40) coated with a partially reflecting layer (44, 46).

11. The device (112) according to any one of the preceding claims, characterized in that the prism arrangement comprises at least a third partially reflecting layer (102, 104) which is angled to the first and second partially reflecting layer (98, 100) is aligned.

2. The device (112) according to claim 11, wherein the prism arrangement has a cube shape, an outer surface of the cube serving as a beam entry surface (106) and at least four of the remaining five outer surfaces each serving as a beam exit surface.