Camera system

Abstract

Camera system (1) comprising: - a housing (2); and - an optoelectronic sensor unit (3) arranged in the housing (2) with at least one detector device (4) and at least one optical system (5) connected upstream of the at least one detector device (4), wherein the optoelectronic sensor unit (3) is elastically mounted relative to the housing (2), - wherein at least one first elastic mounting device (6) connects the optoelectronic sensor unit (3) to the housing (2) in the region of the at least one optical system (5) and wherein at least one second elastic mounting device (7) connects the optoelectronic sensor unit (3) to the housing (2) in the region of the at least one detector device (4), - wherein an image plane (8) of the at least one optical system (5) lies in the region of the center of gravity (9) of the optoelectronic sensor unit (3), and - wherein the center of gravity (9) of the optoelectronic sensor unit (3) lies on the optical axis (10) of the optics (5) and along the optical axis (10) in the middle between the at least one first elastic mounting device (6) and the at least one second elastic mounting device (7).

Description

[0001] The invention relates to a camera system comprising a housing and an optronic sensor unit arranged in the housing.

[0002] Cameras for aircraft, for example aircraft with jet engines, are subject to high demands in terms of their optical lines of sight and their temperature range. When camera systems are used on aircraft, they are subject to high environmental stress due to pressure and temperature differences. High vibration or acceleration loads can occur, which can lead to either parts or components of the cameras being damaged or to the aforementioned high requirements regarding lines of sight no longer being met. The camera systems mentioned above can be arranged in different positions on the aircraft. Cameras can also be located in the area of ​​the engines. This is where particularly strong vibrations and oscillations occur, which have an impact on the camera and its components, in particular the optronic orAn optoelectronic sensor unit with an optical system and a detector device acts. The camera's sensor or detector is particularly sensitive in this regard. It is also very unfavorable if the cameras' natural resonant frequency is in the range of the aircraft's excitation frequency. This can multiply the induced vibrations or accelerations, leading to a resonance catastrophe.

[0003] Further complicating the situation is the fact that such cameras must have a compact design, as the available installation space in aviation is generally very limited. Therefore, the use of thicker or stronger housing walls or corresponding reinforcements is often not an option for these cameras.

[0004] DE 199 06 692 C1 relates to a protective housing for optical devices, in particular for video cameras, which has a tubular housing shell, a window wall at one end, a rear wall at the other end and, inside the housing, a device carrier for the optical device, wherein the device carrier enables the optical device to be moved in the direction of the housing axis.

[0005] WO 2017 / 119302 A1 discloses a vibration damping device that prevents vibration of an electronic device mounted on a mobile body during movement of the mobile body, and that is equipped with the following elements: a mobile body-side lower plate serving as a base; an upper plate for supporting the electronic device; an elastic element arranged between the lower plate and the upper plate and connected to both the lower plate and the upper plate; and a restricting element for restricting horizontal vibration of the electronic device.

[0006] Proceeding from this, the present invention is based on the object of improving a camera system of the type mentioned at the outset, wherein, in particular, high acceleration and / or vibration loads introduced from the outside can act on the camera without causing damage to the camera or its components and without impairing the optical line of sight of the camera.

[0007] This object is achieved according to the invention by a camera system, in particular for vehicles or aircraft, having the features mentioned in claim 1, comprising: - a housing; and - an optoelectronic sensor unit arranged in the housing with at least one detector device and at least one optical unit connected upstream of the at least one detector device, wherein the optoelectronic sensor unit is elastically mounted or suspended relative to the housing.

[0008] Vibration isolation of a camera system or optical system, consisting of a detector and an optical unit, is achieved by elastically suspending this optical unit from the camera housing. The camera system can be, for example, a thermal imaging device or an infrared camera. Due to the elastic mounting of the optoelectronic sensor unit relative to the housing, higher loads can be applied to the camera without damaging the camera or its components or the detector. The reduced loads on the detector also reduce the tilt of the line of sight under vibration excitation. Likewise, the reduction in the loads applied to the camera increases the mean time between failures (MTBF).Thus, at least one means is provided for reducing externally induced mechanical oscillations or vibrations acting on the camera and / or its components.

[0009] The optoelectronic sensor unit can thus form a resonator. This insulation allows for low-frequency decoupling of the internal optical system from external excitation, and the introduced acceleration loads can be minimized through the decoupling and material damping of the elastomer. This low-frequency decoupling allows the resonator to operate in the supercritical frequency range. In contrast to the conventional decoupling of mechanical vibrations, in which an entire device, such as a machine tool, is decoupled from the excitation, the decoupling of vibrations within the camera allows the camera housing to be firmly screwed, especially to an aircraft. This eliminates the need to modify the camera's interface to the aircraft.When the resonator is operated in the supercritical frequency range, the excitation frequency is essentially above the resonance frequency, with damping occurring at, for example, 10 dB per octave. The resonator essentially oscillates itself. At least 25 to 30% of the mass of the entire device can thus be advantageously decoupled from the vibrations acting on the device. This allows for better utilization of the available installation space and a lower overall mass, which is of great importance for use in aircraft. The low-frequency decoupling or tuning of the resonator by the elastic or soft suspension shifts the maximum amplitude of the oscillating system, with the frequencies above this being strongly damped. Operation essentially takes place above the resonance frequency of the resonator.The low-frequency tuning of the resonator achieves a particularly high insulation effect for high-frequency vibrations, such as those found in aircraft with jet engines.

[0010] The optoelectronic sensor unit can be connected to the housing via at least two, in particular annular, elastic mounting devices.

[0011] The elastic bearing devices may comprise elastomer elements, for example made of rubber, which are arranged in particular between metal parts and / or connect them to one another.

[0012] A first, particularly annular, elastic mounting device connects the optoelectronic sensor unit to the housing in the region of the at least one optical unit. A second, particularly annular, elastic mounting device connects the optoelectronic sensor unit to the housing in the region of the at least one detector device.

[0013] It is very advantageous if the elastic bearing devices, in particular those which are annular, are designed in such a way or have such an internal geometry that they have a substantially equal or identical stiffness and / or damping in all three spatial directions.

[0014] The elastic mounting devices can have an internal geometry that allows for virtually identical stiffness in all three spatial directions. This ensures that the resonator's natural frequencies are equal in all three spatial directions. When excited by vibration loads, the relative movements of the optoelectronic sensor unit, including the detector and the associated optics, are at most large enough to prevent any influence on the optical performance.

[0015] The elastic bearing devices can be ring-shaped.

[0016] The annular elastic bearing devices each comprise at least the following: - a metallic inner ring which is arranged on the optoelectronic sensor unit; - a metallic outer ring arranged on the housing; and - an annular elastomer element, in particular made of rubber, via which the metallic inner ring is connected to the metallic outer ring.

[0017] By means of such rubber-metal-elastomer combinations, essentially the same or identical stiffness and / or damping in all three spatial directions can be achieved in an advantageous manner.

[0018] The annular elastomer element can be attached or vulcanized to the metallic inner ring and / or to the metallic outer ring by means of vulcanization.

[0019] An image plane of the at least one optical system lies in the area of ​​the center of gravity of the optoelectronic sensor unit. The optical system can thus be designed such that its relative movements, due to its elastic mounting, have a negligible influence on the accuracy of the line of sight when subjected to vibration excitation.

[0020] The center of gravity of the optoelectronic sensor unit lies on the optical axis of the optics in the middle between the first elastic support device and the second, in particular annular, elastic support device.

[0021] Advantageous embodiments and further developments of the invention are set forth in the dependent claims. An exemplary embodiment of the invention is described below with reference to the drawing.

[0022] They show: Fig. 1 A simplified sectional view of a camera system according to the invention; Fig. 2 is a perspective view of a first annular elastic support device; Fig. 3 a simplified sectional view of the first annular elastic support device from Fig. 2; Fig. 4 is a perspective view of a second annular elastic support device; and Fig. 5 a simplified sectional view of the second annular elastic support device from Fig. 4.

[0023] Functionally identical elements are provided with the same reference numerals in the figures.

[0024] Fig. 1 shows a camera system 1 according to the invention, comprising a housing 2 and an optoelectronic sensor unit 3 arranged in the housing 2, with at least one detector device 4 and at least one optical system 5 connected upstream of the at least one detector device 4. The optoelectronic sensor unit 3 is elastically suspended or mounted relative to the housing 2. The housing 2 further has a window 2a and an interface 2b, for example, for mounting on a vehicle or aircraft.

[0025] The optoelectronic sensor unit 3 is connected to the housing 2 via at least two elastic mounting devices 6, 7. In the present embodiment, the two elastic mounting devices 6, 7 are annular or circumferential. However, other solutions are conceivable in further embodiments not shown.

[0026] As from Fig. 1, at least one first elastic mounting device 6 connects the optoelectronic sensor unit 3 in the region of the at least one optic 5 to the housing 2. At least one second elastic mounting device 7 connects the optoelectronic sensor unit 3 in the region of the at least one detector device 4 to the housing 2. As can be seen from Fig. 1, a simplified image plane 8 of the at least one optics 5 lies at least approximately in the region of the center of gravity 9 of the optoelectronic sensor unit 3 (indicated in a highly simplified manner).

[0027] The optoelectronic sensor unit 3 thus forms a resonator.

[0028] The center of gravity 9 of the optoelectronic sensor unit 3 lies on an optical axis 10 (indicated by dashed lines) of the optics 5 at least approximately in the middle between the at least one first elastic mounting device 6 and the at least one second elastic mounting device 7. The distance between the center of gravity 9 and the first elastic mounting device 6 along the optical axis 10 thus substantially corresponds to the distance between the center of gravity 9 and the second elastic mounting device 7 along the optical axis 10.

[0029] The annular elastic bearing devices 6,7 each have the following: - a metallic inner ring 6a,7a, which is arranged on the optoelectronic sensor unit 3; - a metallic outer ring 6b,7b, which is arranged on the housing 2; and - an annular elastomer element 6c, 7c, in particular made of rubber, via which the metallic inner ring 6a, 7a is connected to the metallic outer ring 6b, 7b.

[0030] The annular elastomer element 6c,7c is vulcanized or attached by vulcanization to the metallic inner ring 6a,7a and / or to the metallic outer ring 6b,7b.

[0031] In the Fig. 2 and Fig. 3 shows the first elastic bearing device 6 with the metallic inner ring 6a, the metallic outer ring 6b and the elastomer element 6c in perspective and in a simplified sectional view. Fig. 4 and Fig. 5 show a substantially identical second elastic bearing device 7 with the metallic inner ring 7a, the metallic outer ring 7b and the annular elastomer element 7c, also in a perspective view and in a simplified sectional view. List of reference symbols: 1 camera system 2 housings 2a Window 2b Interface 3 optoelectronic sensor unit 4 Detector device 5 Optics 6 first elastic support device 7 second elastic support device 6a,7a inner ring 6b,7b outer ring 6c,7c elastomer element 8 Image plane 9 Focus 10 optical axis

Claims

[1] Camera system (1) comprising: - a housing (2); and - an optoelectronic sensor unit (3) arranged in the housing (2) with at least one detector device (4) and at least one optic (5) upstream of the at least one detector device (4), wherein the optoelectronic sensor unit (3) is elastically mounted relative to the housing (2), - wherein at least one first elastic mounting device (6) connects the optoelectronic sensor unit (3) in the area of ​​the at least one optic (5) to the housing (2) and wherein at least one second elastic mounting device (7) connects the optoelectronic sensor unit (3) in the area of ​​the at least one detector device (4) to the housing (2), - wherein an image plane (8) of the at least one optic (5) lies in the region of the center of gravity (9) of the optoelectronic sensor unit (3), and - wherein the center of gravity (9) of the optoelectronic sensor unit (3) lies on the optical axis (10) of the optics (5) and along the optical axis (10) in the middle between the at least one first elastic mounting device (6) and the at least one second elastic mounting device (7). [2] Camera system (1) according to claim 1, wherein the elastic mounting devices (6,7) are designed such that they have substantially the same stiffness and / or damping in all three spatial directions. [3] Camera system (1) according to claim 2, wherein the elastic mounting devices (6,7) have an internal geometry such that they have substantially the same stiffness and / or damping in all three spatial directions. [4] Camera system (1) according to claim 1, 2 or 3, wherein the elastic mounting devices (6, 7) are designed in a ring shape. [5] Camera system (1) according to claim 4, wherein the ring-shaped elastic mounting devices (6,7) each comprise at least the following: - a metallic inner ring (6a,7a) which is arranged on the optoelectronic sensor unit (3); - a metallic outer ring (6b,7b) which is arranged on the housing (2); and - a ring-shaped elastomer element (6c,7c) via which the metallic inner ring (6a,7a) is connected to the metallic outer ring (7a,7b). [6] Camera system (1) according to claim 5, wherein the ring-shaped elastomer element (6c,7c) is made of rubber. [7] Camera system (1) according to claim 5 or 6, wherein the ring-shaped elastomer element (6c,7c) is attached to the metallic inner ring (6a,7a) and / or to the metallic outer ring (6b,7b) by means of vulcanization. [8] Camera system (1) according to one of the preceding claims, wherein the optoelectronic sensor unit (3) forms a resonator.

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