Optical system for use in an underwater environment
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- CARL ZEISS AG
- Filing Date
- 2018-08-31
- Publication Date
- 2026-07-16
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[0001] The invention relates to an optical system for use in an underwater environment. State of the art
[0002] Optical systems, especially (camera) lenses, used in underwater environments must withstand high pressures that act on them depending on the diving depth. Typically, mechanical-optical-electrical systems are encapsulated from the underwater environment by a housing in which quasi-constant (gas) pressure conditions prevail. Optical systems intended to visually capture the environment or parts thereof require an optically transparent interface to the environment within the housing (also called an optical port). For this purpose, the optical port has an optically transparent component made of an optical functional material (usually glass) that is in direct contact with the underwater environment. This optically transparent component must therefore withstand high underwater pressures and pressure fluctuations, depending on the diving depth.
[0003] In previously known optical systems for use in underwater environments, the functional requirement for the optically transparent component is primarily limited to its mechanical load-bearing capacity, i.e., to a sufficiently robust mechanical barrier between the housing interior and the surrounding medium, with the most neutral optical imaging effect possible. Known embodiments of the optically transparent component in the prior art are flat plates or concentric meniscus / dome optics, which are mounted and supported on flat or conical elements (e.g., 45° half the opening angle) facing the housing.
[0004] Thus, in the prior art, the optically transparent component of optical systems is used as an additional component that negatively influences or detracts from the optical imaging properties. As a component positioned upstream of an optical imaging system, the optically transparent component must provide a sufficiently large aperture to achieve the imaging properties required by the optical imaging system. Consequently, the optically transparent component of the optical port, and therefore its area exposed to ambient pressure, is always larger than the functionally necessary dimensions of the first lens of the optical imaging system. This creates a disadvantageous boundary condition for the design of the transparent component of the optical port due to the area-proportional stress resulting from the ambient pressure.
[0005] A disadvantage of optical systems according to the state of the art is that the optically transparent component represents an additional required element in the system, which is heavily stressed by external pressure, since it usually has to be considerably larger than the functionally necessary dimensions of the first lens of an optical imaging system in order to provide it with sufficient aperture, is complex to manufacture, especially in edge-mounted variants, and the optically neutral effect is only partially achieved. Disclosure of the invention
[0006] The invention is based on the objective of demonstrating an optical system for use in an underwater environment which has a high mechanical load-bearing capacity and good optical properties and is technically easy to manufacture.
[0007] This problem is solved by an optical system according to claim 1.
[0008] In particular, the problem is solved by an optical system for use in an underwater environment, wherein the optical system comprises a housing that seals off an interior of the optical system from the environment in a watertight manner, and a lens with an outer surface, wherein the housing has a mount, wherein the lens is received in the mount such that, when the optical system is in the underwater environment, the outer surface is in fluid contact with the water of the underwater environment, wherein the outer surface of the lens has a curved shape, in particular a convex shape, preferably a spherically convex shape, wherein the lens has a first (concave or convex) curved, in particular spherical, contact surface and the mount has a second contact surface, wherein the lens is arranged in the mount such that the first contact surface presses against the second contact surface.when the pressure in the environment of the optical system is higher than the pressure inside the optical system.
[0009] One advantage of this optical system is that the lens can be an optically active component. This allows for a reduction in the number of parts and an increase in the optical performance of the system. The dimensions of the lens, or rather its outer surface, and thus its area exposed to external pressure, can be reduced to the optically functionally required minimum. Furthermore, the optical system exhibits excellent optical properties because the lens, which is in contact with the water in the underwater environment, can be designed and calculated accordingly. The shape of the first contact surface allows it to withstand the varying forces occurring underwater, which depend on the diving depth. Moreover, the first contact surface can be manufactured cost-effectively with exceptional precision.In particular, the first contact surface can be manufactured precisely and easily using conventional optical methods and measured using standard measuring techniques, allowing its quality to be evaluated. This enables the lens, and thus the optical system, to withstand particularly high pressures without damage. The first contact surface can directly touch / contact the second contact surface, or an intermediate layer of an additional material—that is, a material that is not the same as the lens material or the mount material—can be present between the first and second contact surfaces, either partially or completely. The first contact surface can only touch a portion of the second contact surface, or, in underwater environments, a portion of the first contact surface can press against the second contact surface.
[0010] According to one embodiment, the center of the spherical shape of the first contact surface lies on an optical axis of the lens. The advantage of this is that the first contact surface can be manufactured with particularly high precision in a technically simple manner.
[0011] According to one embodiment, the lens has an inner surface opposite the outer surface, wherein an optical axis of the lens passes through the outer surface and the inner surface, and the inner surface of the lens has a curved shape, in particular a concave shape, preferably a spherically concave shape. An advantage of this is that the optical system has a particularly small number of parts.
[0012] According to one embodiment, the first contact surface of the lens has a convex shape, and the second contact surface of the mount has a concave shape with a radius of curvature that essentially corresponds to the radius of curvature of the convex shape of the first contact surface. This results in a particularly large contact area between the first and second contact surfaces. Consequently, the forces caused by the pressure of the underwater environment can be transferred to the mount with minimal stress. The second contact surface can be manufactured, for example, using conventional machining processes. The manufactured first contact surface of the lens can be produced technically easily using common optical manufacturing processes and measured and evaluated very precisely using conventional metrology techniques from optical component manufacturing. This makes it possible to optimally combine the lenses with the second contact surface of the mount with regard to the achieved quality.
[0013] According to one embodiment, the first contact surface has a convex shape, while the second contact surface has a concave shape. In a cross-section along a plane containing the optical axis of the lens, the radius of curvature of the first contact surface is smaller than the radius of curvature of the second contact surface, and the center of the concave shape of the second contact surface does not lie on an optical axis of the lens. With ideal shape and stiffness of the lens, mount, and any intermediate layer, a circular line contact is formed. In practice, a contact surface, or Hertzian contact surface, forms in the contact area of the first and second contact surfaces. This surface, i.e., the area where the first and second contact surfaces touch, is a ring-shaped or annular area symmetrical to the optical axis of the lens. The resulting mechanical stress is determined by the position (i.e.,The position and orientation of the contact surface (Hertzian contact area), the ratio of the radii of curvature of the first and second contact surfaces, the modulus of elasticity at the first (lens) and second (mount) contact surfaces, and the material properties of any intermediate layer are all relevant factors. Even with deviations in the shape and dimensions of the lens and / or mount geometry due to manufacturing variations and / or deformation from stress during operation, the shape of the contact surface (Hertzian contact area) and thus the fundamental contact situation remain unchanged. However, the position and characteristics of the contact surface (Hertzian contact area) do change. The first and second contact surfaces can be designed and manufactured in such a way that the optical system can withstand particularly high pressures without damage.
[0014] According to one embodiment, an elastic intermediate layer and / or an adhesive is arranged between the first and second contact surfaces. This allows the forces and stresses that occur during deformation of the lens and / or the frame to be distributed particularly well and evenly, thus reliably preventing local plastic deformations, especially of the ductile frame components. As a result, the optical system and / or the lens can reliably withstand even higher pressures.
[0015] According to one embodiment, the elastic interlayer and / or the adhesive is designed such that increasing the pressure on the outer surface of the lens enhances the sealing effect between the lens and the housing. An advantage of this is that the self-reinforcing seal reliably prevents water from penetrating the area between the first and second contact surfaces, and thus the interior of the housing, even at high pressures.
[0016] According to one embodiment, the mount has an undercut, whereby surfaces of the undercut are in fluid contact with the underwater environment when the optical system is located underwater. An advantage of this is that, at ambient pressure or water pressure, the bending stress on the mount, and thus the deformation occurring in the mount area (i.e., in the area of the first and second contact surfaces), is minimized by direct, short force transmission in the mount area. This prevents the mount from deforming and / or the shape of the contact surface or Hertzian contact surface from changing significantly due to bending of the mount. Therefore, the optical system can withstand particularly high pressures with exceptional reliability.
[0017] According to one embodiment, the undercut is designed such that the mount, at the level of the undercut, has a diameter perpendicular to the optical axis of the lens that essentially corresponds to the diameter of the lens perpendicular to the optical axis. The advantage of this is that bending or deformation of the mount in the area of the lens or in the area of the second contact surface is minimized. Thus, the optical system can reliably withstand even higher pressures.
[0018] According to one embodiment, the optical system comprises further optical elements, in particular further lenses, wherein the further optical elements are rigidly connected to a part of the mount in such a way that when the lens moves with the mount relative to other parts of the housing, the further optical elements move along with it in such a way that the distances between the lens and the further optical elements remain essentially unchanged. The advantage of this is that the image quality of the optical system remains unchanged even if the lens or the mount is displaced due to stress at high pressures. The further optical elements are moved together with the lens, so that the distances between the further optical elements and the lens do not change.
[0019] According to one embodiment, the first contact surface of the lens is polished and / or etched. This allows for the simple and reliable removal, prevention, or minimization of deep damage, microcracks, or crack nuclei in the first contact surface. As a result, the forces acting upon it can be transferred and guided into the lens mount with exceptional safety and reliability. Consequently, the optical system can reliably withstand even higher pressures.
[0020] According to one embodiment, the lens is pre-tensioned in the mount such that its first contact surface is pressed against the second contact surface, even when the pressure in the vicinity of the optical system is equal to the pressure inside the optical system. In particular, the first lens can be pre-tensioned such that it presses against the second contact surface with a force at least 10 times, preferably at least 50 times, normal atmospheric pressure. This ensures that the position of the lens relative to the mount remains constant even in environments with normal atmospheric pressure. This increases the reliability of the optical system.
[0021] According to one embodiment, a side surface in the form of a cylindrical lateral surface is formed between the outer surface of the lens and the first contact surface of the lens. This allows for simple centering of the lens. Furthermore, the side surface can serve as a sealing surface for sealing in conjunction with sealing elements.
[0022] In one embodiment, the side surface is coaxial with the optical axis of the lens. An advantage of this is that the forces are transferred particularly reliably from the outer surface to the first contact surface. Thus, the lens can withstand particularly high pressures with exceptional reliability.
[0023] According to one embodiment, the optical system further comprises a seal for sealing the area between the first contact surface of the lens and the second contact surface of the mount. This reliably and simply prevents the ingress of water, even at high ambient pressures. Moreover, the contact between the first and second contact surfaces is independent of the seal. This further increases the reliability of the optical system.
[0024] A spherical shape of a surface can, in particular, mean that the surface is a section of the surface of a sphere.
[0025] The optical system can be designed in such a way that it can withstand pressures occurring in deep-sea environments (> 200 m) without damage. Furthermore, the optical system can be designed in such a way that it can withstand pressure differences occurring during ascent and descent to deep-sea depths without damage.
[0026] Preferred embodiments are described in the dependent claims. The invention is explained in more detail below with reference to drawings of exemplary embodiments. These drawings show... Fig. 1 a cross-sectional view of a first embodiment of the optical system according to the invention; Fig. 2 a cross-sectional view of a lens of a second embodiment of the optical system according to the invention; Fig. 3 a cross-sectional view of a third embodiment of the optical system according to the invention; and Fig. 4 a schematic detail view of the optical system Fig. 3.
[0027] In the following description, the same reference numbers are used for identical and similarly functioning parts.
[0028] Fig. Figure 1 shows a cross-sectional view of a first embodiment of the optical system according to the invention. 10 The optical system 10 includes a lens 20 and a housing, wherein the lens 20 in one version 40 the case is enclosed. The case encloses an interior space. 60 compared to the surroundings 50 The optical system 10 It is designed for use in an underwater environment. This means that the optical system 10 and also the housing or the socket 40 can withstand high pressures (e.g., several hundred bar pressure).
[0029] The optical system 10It can be used, for example, for an underwater camera, or it can be an underwater camera.
[0030] The lens 20 represents an optical port, which provides an optically transparent connection through the housing between the interior 60 and the surrounding area 50 forms. In this way, light from the environment can be absorbed. 50 get into the housing.
[0031] The lens 20 has an outer surface 24 on which is designed to contact water. This means that water can cross the outer surface. 24 the lens 20 contacted or touched when the optical system 10 located in an underwater environment.
[0032] The lens 20 It thus represents an outer boundary of the interior space. 60 compared to the surroundings 50 dar.
[0033] The outer surface 24 the lens 20has a curved shape, i.e., the outer surface 24 the lens 20 is not flat. The outer surface 24 the lens 20 can have a spherical shape. The outer surface 24 points in Fig. 1 a spherically convex shape, i.e. one that is curved towards its surroundings 50 curved shape, on.
[0034] However, it is also conceivable that the outer surface 24 the lens 20 has an aspherical shape. For example, the outer surface 24 several subsections, each with a spherical shape and different radii of curvature.
[0035] It is also conceivable that the outer surface 24 the lens 20 has a spherically concave shape, i.e., facing the interior 60 has a curved shape.
[0036] The outer surface 24 the lens 20Opposite lies an inner surface 26 the lens 20 The optical axis 29 runs through the center of the lens 20 and thus through the outer surface 24 and the inner surface 26 The inner surface 26 exhibits a spherically concave shape, i.e., a bulge away from the interior. 60 The center of curvature of the inner surface 26 lies on the optical axis 29 the lens 20 .
[0037] The lens 20 has a first contact surface 28 on. The first contact surface 28 is the version 40 facing the first contact surface 28 lies on the outer surface 24 opposite. The first contact surface 28 is for contacting a second contact surface 48 the version 40 trained. In Fig. 1 touches the first contact surface 28the second contact surface 48 the version 40 immediately or directly. This means that there is no further intermediate layer or similar between the first contact surface and the surface. 28 and the second contact surface 48 is present. The first contact surface 28 thus presses against the second contact surface 48 , when against the outer surface 24 the lens 20 is pressed.
[0038] The first contact surface 28 has a spherical shape, with the center of curvature being the first contact surface 28 on the optical axis 29 the lens 20 lies. The first contact surface 28 points in Fig. 1. A spherically convex shape. The second contact surface 48 It has a spherically concave shape. The center of curvature of the second contact surface 48 lies on the optical axis 29 the lens 20 .
[0039] The first contact surface 28 The inner surface, so to speak, surrounds 26 the lens 20 The first contact surface 28 is a spherical chamfer or facet.
[0040] The radii of curvature of the first contact surface 28 and the second contact surface 48 are the same size or identical. This causes the first contact surface to touch. 28 and the second contact surface 48 large area. The first contact surface 28 is therefore largely complementary or congruent and concentric to the second contact surface. 48 trained. If the environment 50 or the surrounding water 50 against the outer surface 24 the lens 20 Pressing, presses the first contact surface 28 large area against the second contact surface 48 This results in the forces being transferred into the socket with particularly low stress.40 guided. The magnitude of the mechanical stresses occurring in the lens. 20 and version 40 They can therefore be kept low.
[0041] The area where the first contact surface 28 and the second contact surface 48 The contact surface (so-called contact area or Hertzian contact surface) has the shape of a ring-shaped spherical segment.
[0042] The first contact surface 28 the lens 20 It can be polished and / or etched. This removes microcracks and / or deep damage and / or crack nuclei from the lens. 20 minimized. Thus, the lens can 20 withstand higher pressures.
[0043] The shape of the first contact surface 28 It can be manufactured with high precision. Furthermore, its shape can be accurately measured and subsequently evaluated using standard optical measuring methods. This allows for the initial contact surface to be... 28technically simple to manufacture with very high precision. Consequently, especially when the second contact surface 48 also exhibits very high precision, the optical system 10 withstand particularly high pressures.
[0044] By means of the first contact surface 28 can the lens 20 in the version 40 centered or in a desired position relative to the socket 40 be aligned.
[0045] Between the outer surface 24 the lens 20 and the first contact surface 28 the lens 20 is a side surface 27 arranged. The side surface 27 (also called outer cylinder) corresponds to the lateral surface area of a right circular cylinder. The side surface 27 runs coaxially to the optical axis 29 the lens 20 .
[0046] The seal 30to seal the area between the first contact surface 28 and the second contact surface 48 is with the version 40 connected and covers the area between the side surface 27 or the outer cylinder and the socket 40 This can allow water to penetrate the area between the first contact surface. 28 and the second contact surface 48 can be reliably prevented.
[0047] The optical system 10 can include additional optical elements in the interior 60 include the lens 20 typically comprises or consists of a glass material.
[0048] Between the first contact surface 28 and the second contact surface 48 An elastic intermediate layer can be arranged. The elastic intermediate layer can absorb local surface pressure even in the event of deformation of the first contact surface. 28lower the resistance. In particular, the intermediate layer can compensate for manufacturing inaccuracies and / or settling. The elastic intermediate layer can, for example, consist of or comprise an elastic material. If the elastic intermediate layer is present, the first contact surfaces touch or make contact. 28 and the second contact surface 48 not directly / immediately, but only indirectly.
[0049] The elastic intermediate layer and the seal 30 They can be designed in such a way that a self-reinforcing sealing system is present. This means that the sealing effect of the seal is self-reinforcing. 30 or the intermediate layer increases with increasing pressure on the outer surface 24 the lens 20 Instead of or in addition to the intermediate layer, an adhesive or a putty can be used between the first contact surface. 28 and the second contact surface 48 be arranged.
[0050] If an elastic intermediate layer is present, its thickness can be used to determine the radius of curvature of the second contact surface. 48 The radius of curvature of the first contact surface must be taken into account. 28 and the second contact surface 48 is still essentially the same, but may differ slightly (e.g. less than 1%).
[0051] The lens 20 is in such a form 40 arranged that, if in the vicinity 50 of the optical system 10 Normal pressure (1.01325 bar) prevails, the first contact surface 28 with a force corresponding to the effect of a pressure greater than the normal pressure on the outer surface against the second contact surface 48 presses. In particular, the first contact surface 28with a force corresponding to a pressure of approximately 50 bar or approximately 100 bar on the outer surface of the lens, against the second contact surface 48 Pressing while pressing on the outer surface of the lens 20 Only normal pressure exerts pressure. Therefore, movement of the lens is prevented. 20 compared to the version 40 , when the optical system 10 in an environment 50 at normal pressure, reliably prevented. The first contact surface 28 the lens 20 can be done using a screw-on ring 35 or a preload ring or a retaining ring against the second contact surface 48 can be pressed even if the ambient pressure 50 the pressure inside 60 of the optical system 10 This corresponds to (e.g., when the optical system is located outside the underwater environment). The screw-on ring 35 may partially include an intermediate element on the outer surface 24the lens 20 arranged.
[0052] Fig. Figure 2 shows a cross-sectional view of a lens 20 a second embodiment of the optical system according to the invention 10 .
[0053] In Fig. 2 is particularly easy to see, that the center of curvature of the convex first contact surface 28 on the optical axis 29 the lens 20 lies. The side surface 27 , i.e., the outer surface of the lens 20 between first contact surface 28 and the outer surface 24 is in Fig. 2 larger than with the lens 20 the Fig. 1.
[0054] Fig. Figure 3 shows a cross-sectional view of a third embodiment of the optical system according to the invention. 10 . Fig. Figure 4 shows a schematic detail view of the optical system. 10 out of Fig. 3.
[0055] At the in Fig. In the embodiment shown in 3, the first contact surface is 28 and the second contact surface 48 differently trained than at the in Fig. 1 embodiment shown.
[0056] The first contact surface 28 It has a convex shape. The center of curvature of the first contact surface 28 is located on the optical axis 29 the lens 20 The second contact surface 48 It has a concave shape. The center of curvature of the second contact surface 48 It does not lie on the optical axis 29 or symmetry line of the optical system. This causes the first contact surface to touch. 28 and the second contact surface 48 with an ideally rigid shape of the first contact surface 28 and the second contact surface 48 (mathematically speaking, so to speak) in a line that is circular, axially symmetrical around the optical axis 29runs around. When the first contact surface 28 against the second contact surface 48 When pressure is applied, a surface (so-called contact surface or Hertz contact surface) is formed due to the elastic deformation of the lens. 20 and / or the version 40 , which are arranged in a wreath-like or ring-like shape, axially symmetrical around the optical axis of the lens 20 is trained.
[0057] The centers of the curvatures of the first contact surface 28 and the second contact surface 48 are located on a straight line that is perpendicular to the contact surface, in which the first contact surface is situated 28 and the second contact surface 48 touch.
[0058] In case of shape deviations and / or dimensional deviations occurring due to the stress caused by the high pressure on the outer surface 24 the lens 20The shape of the contact area, or Hertzian contact area, remains essentially the same. Only the position and size of the contact area, or Hertzian contact area, change. This can be calculated in simulations, e.g., using the finite element method.
[0059] The contact area or Hertzian contact area between the first contact surface 28 and the second contact surface 48 It therefore has a shape that is symmetrical to the axis of symmetry or the optical axis of the lens. 20 is. The contact surface is in the in Fig. 4 cross-sectional view shown (for an ideally rigid lens) 20 and an ideally rigid frame 40 ) point-like. The contact area or Hertzian contact area between the first contact surface 28 and the second contact surface 48 In reality, this is due to less lens deformation. 20 and / or the version40 The shape is that of an annular funnel section or the lateral surface of a truncated cone. The cross-section of the contact surface or Hertzian contact surface parallel to the optical axis then has the shape of a line.
[0060] If an intermediate layer and / or an adhesive is used between the first contact surface 28 and the second contact surface 48 When arranged, the two contact surfaces touch. 28 , 48 not immediately / directly. The areas where the two contact surfaces meet. 28 , 48 They would touch if there were no intermediate layer, but press against each other if an intermediate layer or adhesive is present.
[0061] The radii of curvature of the first contact surface 28 and the second contact surface 48In simulations (e.g., using the finite element method), the parameters can be determined or optimized in such a way that, under expected underwater pressures, the mechanical stresses are limited to a level that the lens or optical system can withstand without damage. This allows the lens to be used in a more durable and reliable manner. 20 or the optical system 10 also withstand particularly high pressures.
[0062] A seal is located between the side surface. 27 and the version 40 arranged. The seal 30 seals the area between the side surface 27 or the outer cylinder and the socket 40 This makes it waterproof. This prevents water from penetrating the area between the first contact surface. 28 and the second contact surface 48 or between the side surface 27 and the version 40 reliably prevented.
[0063] The version 40The optical axis points one 29 the lens 20 circumferential undercut 42 or an indentation or constriction. At the level of the undercut. 42 the version 40 a smaller diameter perpendicular to the optical axis 29 the lens 20 on than in the rest of the version 40 The undercut 42 or the areas 43 the undercut is in contact with the surroundings 50 in fluid connection. This means that, for example, in an underwater environment, water is subject to the same pressure at which the water reaches the outer surface. 24 the lens 20 and the outside of the frame presses into the undercut 42 This results in bending moments in the area of the first contact surface due to a short, direct force path. 28 and the second contact surface 48 minimized, as the water in the undercut 42so to speak, against the water that is coming from a marginal area 70 the version 40 presses that goes towards the lens 20 is adjacent, presses.
[0064] A deformation of the second contact surface 48 This minimizes or even prevents the contact area from changing. In other words, at the level of the undercut... 42 the outer surface of the housing or socket 40 and the areas 43 of the undercut 42 equally subjected to pressure. Thus, it lies in the edge area of the socket. 40 A short, direct force flow without bending moments occurs. This reduces the bending stress on the socket. 40 in areas of the first contact surface 28 and the second contact surface 48 minimized.
[0065] At the level of the undercut 42 the version 40 a diameter perpendicular to the optical axis29 the lens 20 (the optical axis 29 runs in Fig. 3 from top to bottom or vice versa), which essentially corresponds to the diameter of the lens 20 perpendicular to the optical axis 29 the lens 20 This corresponds to the bending stress and resulting deformation of the part of the socket. 40 in the area of the second contact surface 48 minimized. In an underwater environment, the water pressure in the undercut is minimized. 42 against the water that falls on the part or the edge area 70 the version 40 presses that is located at the level of the outer surface 24 the lens 20 is located (the height runs in Fig. 3 from top to bottom or vice versa). Bending moments are thus determined from the first contact surface. 28 and the second contact surface 48 kept away.
[0066] The optical system 10It features additional optical elements (e.g., additional lenses, CCD sensors, etc.) (not shown). These additional optical elements are located on one of the lenses. 20 or the second contact surface 48 opposite plan surface 71 the version 40 and not directly on other parts of the housing next to the socket 40 fixed. In the case of an axial displacement (i.e., a displacement along the optical axis) 29 ) the lens 20 and the version 40 compared to the other parts of the housing due to the pressure of the water in the environment 50 The other optical elements shift by the same amount as the lens. 20 was shifted. Thus, the distances between the optical elements of the optical system remain unchanged. 10 regardless of the ambient pressure 50 The same size. Consequently, the optical imaging quality of the optical system remains unchanged.10 the same size.
[0067] The drawings show the housing or the socket. 40 Each is only partially shown. Reference symbol list 10 optical system 20 lenses 24 Exterior surface 26 Interior surface 27 side surface 28 first contact surface 29 optical axis of the lens 30 Seal 35 Screw-on ring 40 version 42 Undercut 43 Area of the undercut 48 second contact surface 50 surroundings 60 Interior 70 Edge area of the frame 71 Plan area of the version
Claims
[1] Optical system (10) for use in an underwater environment, wherein the optical system (10) a housing that seals off an interior (60) of the optical system (10) from the environment (50) in a watertight manner, and a lens (20) with an outer surface (24) includes wherein the housing has a socket (40) wherein the lens (20) is received in the socket (40) such that, when the optical system (10) is in the underwater environment, the outer surface (24) of the lens (20) is in fluid contact with water of the underwater environment, wherein the outer surface (24) of the lens (20) has a curved shape, in particular a convex shape, preferably a spherically convex shape, wherein the lens (20) has a first curved, in particular spherical, contact surface (28) and the mount (40) has a second contact surface (48), wherein the lens (20) is arranged in the mount (40) such that the first contact surface (28) presses against the second contact surface (48) when the pressure of the environment (50) of the optical system (10) is higher than the pressure in the interior (60) of the optical system (10). [2] Optical system (10) according to claim 1, wherein the center of the spherical shape of the first contact surface (28) lies on an optical axis (29) of the lens (20). [3] Optical system (10) according to claim 1 or 2, wherein the lens (20) has an inner surface (26) opposite the outer surface (24), wherein an optical axis (29) of the lens (20) passes through the outer surface (24) and the inner surface (26), and wherein the inner surface (26) of the lens (20) has a curved shape, in particular a concave shape, preferably a spherical-concave shape. [4] Optical system (10) according to one of claims 1-3, wherein the first contact surface (28) of the lens (20) has a convex shape, and wherein the second contact surface (48) of the mount (40) has a concave shape with a radius of curvature that substantially corresponds to a radius of curvature of the convex shape of the first contact surface (28). [5] Optical system (10) according to one of claims 1-3, wherein the first contact surface (28) has a convex shape, wherein the second contact surface (48) has a concave shape, wherein in a cross-section along a plane containing the optical axis (29) of the lens (20) the radius of curvature of the first contact surface (28) is smaller than the radius of curvature of the second contact surface (48), and wherein the center of the concave shape of the second contact surface (48) does not lie on an optical axis (29) of the lens (20). [6] Optical system (10) according to one of the preceding claims, wherein an elastic intermediate layer and / or an adhesive is arranged between the first contact surface (28) and the second contact surface (48). [7] Optical system (10) according to claim 6, wherein the elastic interlayer and / or the adhesive is designed such that when the pressure on the outer surface (24) of the lens (20) is increased, a sealing effect between the lens (20) and the mount (40) is increased. [8] Optical system (10) according to one of the preceding claims, wherein the mount (40) has an undercut (42), wherein surfaces (43) of the undercut (42) are in fluid contact with the underwater environment when the optical system (10) is located in the underwater environment. [9] Optical system (10) according to claim 8, wherein the undercut (42) is designed such that the mount (40) at the level of the undercut (42) has a diameter perpendicular to the optical axis (29) of the lens (20) which substantially corresponds to the diameter of the lens (20) perpendicular to the optical axis (29) of the lens (20). [10] Optical system (10) according to one of the preceding claims, wherein the optical system (10) comprises further optical elements, in particular further lenses, wherein the further optical elements are rigidly connected to a part of the mount (40) in such a way that when the lens (20) is moved with the mount (40) relative to other parts of the housing, the further optical elements are moved accordingly in such a way that the distances between the lens (20) and the further optical elements do not change substantially. [11] Optical system (10) according to one of the preceding claims, wherein the first contact surface (28) of the lens (20) is polished and / or etched. [12] Optical system (10) according to one of the preceding claims, wherein the lens (20) is pre-tensioned in the mount (40) such that the lens (20) presses with its first contact surface (28) against the second contact surface (48), even when the pressure in the vicinity of the optical system (10) is equal to the pressure in the interior (60) of the optical system (10). [13] Optical system (10) according to one of the preceding claims, wherein a side surface (27) in the form of a lateral surface of a cylinder is formed between the outer surface (24) of the lens (20) and the first contact surface (28) of the lens (20). [14] Optical system (10) according to claim 13, wherein the side surface (27) is coaxial to the optical axis (29) of the lens (20). [15] Optical system (10) according to one of the preceding claims, wherein the optical system (10) further comprises a seal (30) for sealing an area between the first contact surface (28) of the lens (20) and the second contact surface (48) of the mount (40).