阅读说明：本技术 在水下环境中使用的光学系统 (Optical system for use in an underwater environment ) 是由 安德烈亚斯·凯撒-费尔斯坦 马里奥·桑德曼 安德烈亚·伯纳 汉斯·兰格 德克·德林 尤维· 于 2019-08-20 设计创作，主要内容包括：提出了一种在水下环境中使用的光学系统(10),其中,光学系统(10)包括：以水密方式相对于周围环境(50)界定光学系统(10)内部(60)的壳体；以及具有外表面(24)的透镜(20),其中,该壳体包括安装座(40),其中,透镜(20)被接纳在安装座(40)中,其方式使得当光学系统(10)位于水下环境中时,透镜(20)的外表面(24)与水下环境的水处于流体接触,其中,透镜(20)的外表面(24)具有拱形形式,特别是凸面形式,优选为球面凸面形式,其中,透镜(20)具有拱形的第一接触面(28),特别是球面接触面,并且安装座(40)具有第二接触面(48),其中,透镜(20)布置在安装座(40)中,其方式使得当光学系统(10)的周围环境(50)的压力大于光学系统(10)内部(60)的压力时,第一接触面(28)压在第二接触面(48)上。(An optical system (10) for use in an underwater environment is proposed, wherein the optical system (10) comprises: a housing defining an interior (60) of the optical system (10) in a watertight manner with respect to a surrounding environment (50); and a lens (20) having an outer surface (24), wherein the housing includes a mount (40), wherein the lens (20) is received in the mount (40) in such a way that when the optical system (10) is located in an 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 an arcuate form, in particular a convex form, preferably a spherical convex form, wherein the lens (20) has an arched first contact surface (28), in particular a spherical contact surface, and the mount (40) has a second contact surface (48), wherein the lens (20) is arranged in the mount (40) in such a way that the first contact surface (28) presses on the second contact surface (48) when the pressure of the surroundings (50) of the optical system (10) is greater than the pressure of the interior (60) of the optical system (10).)

1. An optical system (10) for use in an underwater environment,

the optical system (10) comprises:

a housing defining an interior (60) of the optical system (10) in a watertight manner with respect to a surrounding environment (50), and a lens (20) having an outer surface (24),

wherein the housing comprises a mount (40), wherein the lens (20) is received in the mount (40) in such a way that an outer surface (24) of the lens (20) is in fluid contact with water of the underwater environment when the optical system (10) is located in the underwater environment,

wherein the outer surface (24) of the lens (20) has an arched form, in particular a convex form, preferably a spherical convex form, wherein the lens (20) has an arched first contact surface (28), in particular a spherical contact surface, and the mount (40) has a second contact surface (48),

wherein the lens (20) is arranged in the mount (40) in such a way that the first contact surface (28) presses against the second contact surface (48) when the pressure of the surroundings (50) of the optical system (10) is greater than the pressure of the interior (60) of the optical system (10).

2. The optical system (10) of claim 1,

the center of the spherical form of the first contact surface (28) is located on the optical axis (29) of the lens (20).

3. The optical system (10) of claim 1 or 2,

the lens (20) has an inner surface (26) opposite the outer surface (24), wherein an optical axis (29) of the lens (20) extends through the outer surface (24) and the inner surface (26), and wherein the inner surface (26) of the lens (20) has an arcuate form, in particular a concave form, preferably a spherical concave form.

4. The optical system (10) of any one of claims 1 to 3,

the first contact surface (28) of the lens (20) has a convex form and

wherein the second contact surface (48) of the mounting seat (40) has a concave form with a radius of curvature substantially corresponding to the radius of curvature of the convex form of the first contact surface (28).

5. The optical system (10) of any one of claims 1 to 3,

the first contact surface (28) has a convex form,

wherein the second contact surface (48) has a concave form,

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 form of the second contact surface (48) is not located on the optical axis (29) of the lens (20).

6. The optical system (10) of any one of the preceding claims,

an elastic intermediate layer and/or an adhesive is arranged between the first contact surface (28) and the second contact surface (48).

7. The optical system (10) of claim 6,

the resilient intermediate layer and/or the adhesive is formed in such a way that the sealing effect between the lens (20) and the mount (40) increases when the pressure on the outer surface (24) of the lens (20) increases.

8. The optical system (10) of any one of the preceding claims,

the mount (40) has an undercut (42), wherein a face (43) of the undercut (42) is in fluid connection with the underwater environment when the optical system (10) is located in the underwater environment.

9. The optical system (10) of claim 8,

the undercut (42) is embodied such that, flush with the undercut (42), a diameter of the mounting (40) perpendicular to the optical axis (29) of the lens (20) substantially corresponds to a diameter of the lens (20) perpendicular to the optical axis (29) of the lens (20).

10. The optical system (10) of any one of the preceding claims,

the optical system (10) comprises further optical elements, in particular further lenses, wherein the further optical elements are rigidly connected to a portion of the mount (40) in such a way that when the lens (20) is moved with the mount (40) relative to the rest of the housing, the further optical elements are correspondingly moved together in such a way that the distance between the lens (20) and the further optical elements is substantially unchanged.

11. The optical system (10) of any one of the preceding claims,

the first contact surface (28) of the lens (20) is polished and/or etched.

12. The optical system (10) of any one of the preceding claims,

the lens (20) is arranged in the mounting (40) with pretension in such a way that the first contact surface (28) of the lens (20) presses against the second contact surface (48) even if the pressure of the surroundings of the optical system (10) is equal to the pressure of the interior (60) of the optical system (10).

13. The optical system (10) of any one of the preceding claims,

a lateral 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. The optical system (10) of claim 13,

the side surface (27) extends coaxially with respect to an optical axis (29) of the lens (20).

15. The optical system (10) of any one of the preceding claims,

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).

Technical Field

The present invention relates to an optical system for use in an underwater environment.

Background

The optical systems used in underwater environments, i.e. in particular the (camera) lenses, have to withstand high pressures acting on the optical system depending on the depth of the dive. Typically, the mechanical optical electrical system is enclosed from the water of the underwater environment by a housing in which quasi-constant (gas) pressure conditions prevail. An optical system that should visually capture the surrounding environment or a portion of the surrounding environment requires an optically transparent interface with the surrounding environment (also referred to as an optical port) in the housing. To this end, the optical port comprises an optically transparent member made of an optically functional material (typically glass) in direct contact with the underwater environment. Thus, the optically transparent member must withstand the high pressures of the underwater environment, which depend on the depth of the dive, as well as pressure variations.

In previously known optical systems used in underwater environments, the functional requirements for optically transparent components are mainly limited to mechanical load-bearing capacity, i.e. to a mechanically sufficient limit with respect to the load-bearing capacity of the interior of the housing relative to the ambient medium, wherein the optical imaging effect is as neutral as possible. Examples of optically transparent members included in the prior art are flat or concentric meniscus/dome optical units that are held and supported relative to the housing on a planar or conical design element (e.g., 45 deg. half-aperture angle).

Therefore, the optically transparent member of the optical system in the prior art is used as an additional member having a negative influence/non-conductive effect on the optical imaging characteristics. As a component disposed in front of the optical imaging system, the optically transparent component must have sufficient apertures for the imaging characteristics required by the optical imaging system. As a result, the optically transparent part of the optical port, and therefore its area exposed to ambient pressure, is always larger than the functionally required size of the first lens of the optical imaging system. As a result, it is disadvantageous to design the boundary conditions of the transparent member of the optical port in consideration of the load caused by the ambient pressure and proportional to the area.

A disadvantage of the optical system corresponding to the prior art is that the optically transparent component represents an additional necessary element in the system which is under great load due to external pressure, since it must generally be much larger than the functionally required size of the first lens of the optical imaging system in order to provide the first lens with sufficient aperture, which optical system is complicated to manufacture, in particular in the case of variants which remain at the edge and achieve an optically neutral effect only to a limited extent.

Disclosure of Invention

The object on which the invention is based is to highlight an optical system for use in an underwater environment, which has a high mechanical load-bearing capacity, has good optical properties and is easy to produce from a technical point of view.

This object is achieved by an optical system as claimed in claim 1.

In particular, the object is achieved by an optical system for use in an underwater environment, wherein the optical system comprises: a housing defining an interior of the optical system in a watertight manner with respect to a surrounding environment; and a lens having an outer surface, wherein the housing comprises a mount, wherein the lens is received in the mount in such a way that the outer surface is in fluid contact with water of the underwater environment when the optical system is located in the underwater environment, wherein the outer surface of the lens has an arcuate form, in particular a convex form, preferably a spherical convex form, wherein the lens has a (concave or convex) arcuate first contact surface, in particular a spherical contact surface, and the mount has a second contact surface, wherein the lens is arranged in the mount in such a way that the first contact surface presses on the second contact surface when the pressure of the surroundings of the optical system is greater than the pressure inside the optical system.

An advantage of this optical system is that the lens can be an optically effective component. This can reduce the number of parts of the optical system and improve the optical performance of the optical system. The size of the lens or the outer surface of the lens and thus its area exposed to external pressure can be reduced to the extent required for the optical function. Furthermore, the optical system has very good optical properties, since lenses in contact with water in an underwater environment can be designed or calculated accordingly. Due to the form of the first contact surface, forces occurring in an underwater environment which are (variable) depending on the depth of the dive can be tolerated particularly well. Furthermore, the first contact surface can be produced particularly cost-effectively with high precision. In particular, the first contact surface can be precisely manufactured in a technically simple manner using conventional optical methods and can be measured using conventional measuring methods, and the quality of the first contact surface can be evaluated. As a result, the lens and thus the optical system can withstand particularly high pressures without being damaged. The first contact surface may touch/contact the second contact surface immediately or directly, or there may be an intermediate layer made of an additional material (i.e. a material different from the material of the lens and different from the material of the mount) present at least in some areas or over the whole area between the first contact surface and the second contact surface. In an underwater environment, the first contact surface can only touch a part of the second contact surface or a part of the first contact surface can press against the second contact surface or a part of the second contact surface.

According to an embodiment, the center of the spherical form of the first contact surface is located on the optical axis of the lens. This has the advantage that the first contact surface can be produced in a technically simple manner with particularly high precision.

According to an embodiment, the lens has an inner surface opposite to the outer surface, wherein the optical axis of the lens extends through the outer and inner surfaces, and wherein the inner surface of the lens has an arcuate form, in particular a concave form, preferably a spherical concave form. This has the advantage that the optical system has a particularly small number of components.

According to an embodiment, the first contact surface of the lens has a convex form and the second contact surface of the mount has a concave form with a radius of curvature substantially corresponding to the radius of curvature of the convex form of the first contact surface. As a result, a particularly large area of contact is present between the first contact surface and the second contact surface. Thus, the forces generated by the pressure of the underwater environment can be transmitted into the mounting socket with little tension. The second contact surface can be produced, for example, by conventional machining methods. The first contact surface of the produced lens can be produced in a technically simple manner using conventional optical device manufacturing methods and can be measured and evaluated very accurately by means of conventional measuring techniques in the production of optical components. As a result, the lens can be bonded in an optimum manner to the second contact surface of the mount in respect of the quality achieved.

According to an embodiment, the first contact surface has a convex form, wherein the second contact surface has a concave form, wherein, 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 wherein the center of the concave form of the second contact surface is not located on the optical axis of the lens. With the desired shape and rigidity of the lens, the mount and possibly the intermediate layer, a circular line contact is produced. In practice, a touched region or a region having hertzian stress, i.e., a region where the first contact surface and the second contact surface touch, a ring-shaped or annular region formed symmetrically with respect to the optical axis of the lens is formed in the touched region of the first contact surface and the second contact surface. The resulting mechanical stress is influenced by the relative positions (i.e. position and orientation) of the touch region or regions with hertzian stress, the ratio of the radii of curvature of the first and second contact surfaces, the young's modulus at the first contact surface or lens and the second contact surface or mount, and the material properties of the material of the intermediate layer, if present. In the case of deviations in the form and size of the lens geometry and/or the mount geometry, the form of the contact region or the region with hertzian stress and therefore the basic contact condition remains unchanged, taking into account manufacturing deviations and/or taking into account load-induced deformations during operation. The relative position and behavior of the touch region or regions with hertzian stress changes in the process. The first and second contact surfaces may be designed or created or produced in such a way that the optical system can withstand particularly high pressures without being damaged.

According to an embodiment, the resilient intermediate layer and/or the adhesive is arranged between the first contact surface and the second contact surface. As a result, the forces or stresses occurring when the lens and/or the mount are deformed can be distributed particularly well or uniformly and the occurrence of local plastic deformations, in particular of ductile mount parts, can be reliably avoided. Thus, the optical system or lens can reliably withstand even higher pressures.

According to an embodiment, the resilient intermediate layer and/or the adhesive is formed in such a way that the sealing effect between the lens and the mount is increased when the pressure on the outer surface of the lens is increased. This has the advantage that, even at high pressures, the entry of water into the region between the first contact surface and the second contact surface and thus into the interior of the housing is avoided particularly reliably by the self-reinforcing seal.

According to an embodiment, the mount has an undercut, wherein a face of the undercut is in fluid connection with the underwater environment when the optical system is located in the underwater environment. This has the advantage that, in the case of ambient or water pressure, the direct, short-term introduction of force into the region of the mount minimizes the bending load on the mount and thus the deformation occurring in the region of the mount, i.e. in the region of the first and second contact faces. This therefore avoids deformation of the mount and/or substantial changes in the form of the touch region or region with hertzian stress in view of flexure of the mount. The optical system can therefore be subjected to particularly high pressures particularly reliably.

According to an embodiment, the undercut is implemented such that, flush with the undercut, a diameter of the mount perpendicular to the optical axis of the lens substantially corresponds to a diameter of the lens perpendicular to the optical axis of the lens. This has the advantage that the bending or deformation of the mount in the region of the lens or in the region of the second contact surface is minimized. Therefore, the optical system can reliably withstand even higher pressures.

According to an 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 lenses are moved with the mount relative to the rest of the housing, the further optical elements are correspondingly moved together in such a way that the distance between the lenses and the further optical elements is substantially unchanged. This has the advantage that the imaging quality of the optical system remains unchanged even in the case of a displacement of the lens or the mount due to a load under high pressure. The further optical element is displaced together with the lens, so that the distance between the further optical element and the lens does not change.

According to an embodiment, the first contact surface of the lens is polished and/or etched. As a result, deep damage or micro-cracks or crack nuclei in the first contact surface can be reliably removed or avoided/minimized in a technically simple manner. As a result, the forces generated can be transmitted or guided particularly safely and reliably into the mounting socket. Therefore, the optical system can reliably withstand even higher pressures.

According to one embodiment, the lens is arranged in the mount pretensioned in such a way that the first contact surface of the lens presses against the second contact surface, even if the pressure of the surroundings of the optical system is equal to the pressure inside the optical system. In particular, the first lens may be pretensioned in such a way that it presses against the second contact surface with a force corresponding to at least 10 times, preferably at least 50 times, the normal pressure. This ensures that the position of the lens relative to the mount remains constant even in the presence of a standard atmospheric pressure in the surrounding environment. This improves the reliability of the optical system.

According to an embodiment, a side surface in the form of a lateral surface of the cylinder is formed between the outer surface of the lens and the first contact surface of the lens. This allows the lens to be technically simply centered. Furthermore, the side faces can serve as sealing faces for sealing with the sealing element.

According to an embodiment, the side faces extend coaxially with respect to the optical axis of the lens. This has the advantage that the force is transmitted particularly reliably from the outer surface to the first contact surface. The lens can thus withstand high pressures particularly reliably.

According to an embodiment, the optical system further comprises a seal for sealing an area between the first contact surface of the lens and the second contact surface of the mount. This reliably prevents water from entering in a technically simple manner even under high ambient pressure. Furthermore, the contact between the first contact surface and the second contact surface is independent of the seal. This improves the reliability of the optical system even further.

The spherical form of the surface may particularly mean that the surface is a spherical surface segment.

In particular, the implementation of the optical system may be such that it can withstand the pressures occurring in deep sea environments (>200m) without being damaged. Furthermore, the embodiment of the optical system can be such that the optical system can withstand without damage, in particular, pressure differences occurring when floating out of the water or diving down into deep sea.

Drawings

Preferred embodiments are evident from the dependent claims. The invention is explained in more detail below with reference to the drawings of exemplary embodiments. In the drawings:

fig. 1 shows a cross-sectional view of a first embodiment of an optical system according to the invention;

fig. 2 shows a cross-sectional view of a lens of a second embodiment of the optical system according to the invention;

fig. 3 shows a cross-sectional view of a third embodiment of the optical system according to the invention; and

fig. 4 shows a schematic detailed view of the optical system of fig. 3.

Detailed Description

In the following description, the same reference numerals are used for the same parts and parts having the same effects.

Fig. 1 shows a cross-sectional view of a first embodiment of an optical system 10 according to the invention. The optical system 10 comprises a lens 20 and a housing, wherein the lens 20 is received in a mount 40 of the housing. The housing defines an interior 60 relative to the ambient environment 50. The optical system 10 is implemented for use in an underwater environment. This means that the optical system 10 and also the housing or mount 40 can withstand high pressures (e.g. pressures of several hundred bar).

For example, the optical system 10 may be used in or may be an underwater camera.

Lens 20 represents an optical port that forms a light-transmissive or transparent connection through the housing between interior 60 and ambient environment 50. In this way, light from the ambient environment 50 may enter the housing.

The lens 20 has an outer surface 24 which is embodied in contact with water. This means that when the optical system 10 is located in an underwater environment, water contacts or touches the outer surface 24 of the lens 20. Thus, lens 20 represents the outer boundary of interior 60 relative to ambient environment 50.

The outer surface 24 of the lens 20 has an arcuate form, i.e. the outer surface 24 of the lens 20 is not flat. The outer surface 24 of the lens 20 may have a spherical form. In fig. 1, the outer surface 24 is in the form of a spherical convex surface, i.e. arched towards the surroundings 50.

However, it is also conceivable for the outer surface 24 of the lens 20 to have an aspherical form. For example, the outer surface 24 may have a plurality of sub-segments, each sub-segment having a spherical form with a radius of curvature different from each other.

It is also conceivable that the outer surface 24 of the lens 20 has a spherical concave form, i.e. a form that is arched towards the interior 60.

The outer surface 24 of the lens 20 is opposite the inner surface 26 of the lens 20. An optical axis 29 extends through the center of the lens 20 and, therefore, through the outer surface 24 and the inner surface 26. The inner surface 26 has a spherical concave form, i.e., curves away from the interior 60. The center of curvature of the inner surface 26 is located on the optical axis 29 of the lens 20.

The lens 20 has a first contact surface 28. The first contact surface 28 faces the mounting seat 40. The first contact surface 28 is opposite the outer surface 24. The first contact surface 28 is formed to contact the second contact surface 48 of the mount 40. In fig. 1, the first contact surface 28 immediately or directly touches the second contact surface 48 of the mount 40. This means that there is no further intermediate layer or the like between the first contact surface 28 and the second contact surface 48. Thus, if there is pressure on the outer surface 24 of the lens 20, the first contact surface 28 presses against the second contact surface 48.

The first contact surface 28 has a spherical form, wherein the center of curvature of the first contact surface 28 is located on the optical axis 29 of the lens 20. In fig. 1, the first contact surface 28 has the form of a spherical convex surface. The second contact surface 48 has a spherical concave form. The center of curvature of the second contact surface 48 is located on the optical axis 29 of the lens 20.

The first contact surface 28 can be said to extend around the inner surface 26 of the lens 20. The first contact surface 28 is a spherical bevel or facet.

The radii of curvature of the first contact surface 28 and the second contact surface 48 are equal or the same size. As a result, the first contact surface 28 and the second contact surface 48 touch over a large area. The first contact surface 28 is thus embodied largely in a complementary or congruent and concentric manner with respect to the second contact surface 48. When the ambient environment 50 or water in the ambient environment 50 presses on the outer surface 24 of the lens 20, the first contact surface 28 presses over a large area against the second contact surface 48. As a result, the generated forces are directed into the mount 40 and the tension is particularly small. Therefore, the magnitude of the mechanical stress generated in the lens 20 and the mount 40 can be kept low.

The region where the first contact surface 28 and the second contact surface 48 touch (the so-called touch region or region with hertzian stress) has the form of an annular spherical segment.

The first contact surface 28 of the lens 20 may be polished and/or etched. This minimizes micro-cracks and/or deep damage and/or crack nuclei in the lens 20. Therefore, the lens 20 can withstand a high pressure.

The form of the first contact surface 28 can be produced very accurately. Furthermore, the format can be captured very accurately and can therefore be evaluated using conventional optical measurement methods. The first contact surface 28 can thus be produced in a technically simple manner with very high precision. The optical system 10 can therefore be subjected to particularly high stresses, in particular if the second contact surface 48 likewise has a very high accuracy.

By means of the first contact surface 28, the lens 20 can be centered in the mount 40 or aligned in a desired position relative to the mount 40.

The side surface 27 is arranged between the outer surface 24 of the lens 20 and a first contact surface 28 of the lens 20. The side surface 27 (also referred to as the outer cylinder) corresponds to the lateral surface of the right cylinder. The side surface 27 extends coaxially with respect to the optical axis 29 of the lens 20.

A seal 30 for sealing the area between the first contact surface 28 and the second contact surface 48 is connected to the mounting 40 and covers the side surface 27 or the area between the outer cylinder and the mounting 40. This can reliably prevent water from entering the area between the first contact surface 28 and the second contact surface 48.

Optical system 10 may include additional optical elements within interior 60. The lens 20 comprises or is typically composed of a glass material.

An elastic intermediate layer may be arranged between the first contact surface 28 and the second contact surface 48. The resilient intermediate layer may reduce the local surface pressure generated even when the first contact surface 28 is deformed. In particular, the intermediate layer may compensate for manufacturing errors and/or signs of settling. For example, the elastic intermediate layer may be composed of or comprise an elastic material. If an elastic intermediate layer is present, the first contact surface 28 and the second contact surface 48 do not directly/immediately touch or contact each other, but only indirectly.

Embodiments of the resilient intermediate layer and the seal 30 may be such that a self-reinforcing sealing system is present. This means that the sealing effect of the sealing member 30 or intermediate layer increases as the pressure on the outer surface 24 of the lens 20 increases. Instead of or in addition to an intermediate layer, an adhesive or glue may be arranged between the first contact surface 28 and the second contact surface 48.

If an elastic intermediate layer is present, the thickness of the second contact surface 48 may be taken into account when setting its radius of curvature. The radii of curvature of the first and second contact surfaces 28, 48 are then still substantially the same, but may differ slightly from each other (e.g., less than 1%).

The lens 20 is arranged in the mount 40 in such a way that, when the surroundings 50 of the optical system 10 are at standard atmospheric pressure (1.01325 bar), the first contact surface 28 presses against the second contact surface 48 with a force corresponding to a pressure effect greater than the standard atmospheric pressure on the outer surface. In particular, the first contact surface 28 may press against the second contact surface 48 with a force corresponding to a pressure of about 50 bar or about 100 bar on the outer surface of the lens, while only normal atmospheric pressure is on the outer surface of the lens 20. Therefore, when the optical system 10 is in the ambient environment 50 at the normal atmospheric pressure, the movement of the lens 20 with respect to the mount 40 is reliably prevented. Even if the pressure of the surroundings 50 corresponds to the pressure of the interior 60 of the optical system 10 (for example if the optical system is located outside the underwater environment), the first contact surface 28 of the lens 20 can be pressed against the second contact surface 48 by means of the screw ring 35 or the pretensioning ring or the locking ring. The screw ring 35 is arranged partially on the outer surface 24 of the lens 20, if necessary with intermediate elements.

Fig. 2 shows a cross-sectional view of a lens 20 of a second embodiment of the optical system 10 according to the invention.

The fact that the center of curvature of the convex first contact surface 28 lies on the optical axis 29 of the lens 20 can be recognized particularly well in fig. 2. The side surface 27, i.e. the outer surface of the lens 20 between the first contact surface 28 and the outer surface 24, is larger in fig. 2 than in the case of the lens 20 in fig. 1.

Fig. 3 shows a cross-sectional view of a third embodiment of the optical system 10 according to the invention. Fig. 4 shows a schematic detailed view of the optical system 10 of fig. 3.

In the embodiment shown in fig. 3, the first contact surface 28 and the second contact surface 48 have a different form than the embodiment shown in fig. 1.

The first contact surface 28 has a convex form. The center of curvature of the first contact surface 28 is located on the optical axis 29 of the lens 20. The second contact surface 48 has a concave form. The center of curvature of the second contact surface 48 is not located on the optical axis 29 or the line of symmetry of the optical system. In the case of an ideal rigid form of the first contact surface 28 and the second contact surface 48, the first contact surface 28 and the second contact surface 48 therefore touch along a line (which can be said to be mathematically considered) which extends in a circularly axisymmetric manner around the optical axis 29. If the first contact surface 28 is pressed against the second contact surface 48, a region (so-called touch region or region with hertzian stress) is formed in a ring-like or ring-like axisymmetric manner around the optical axis of the lens 20 in view of the elastic deformation of the lens 20 and/or the mount 40.

The centers of curvature of the first contact surface 28 and the second contact surface 48 lie on a line perpendicular to the touch region in which the first contact surface 28 and the second contact surface 48 touch.

The form of the touch region or the region with hertzian stress remains substantially unchanged when considering form deviations and/or dimensional deviations due to loads caused by high pressure on the outer surface 24 of the lens 20. The relative position and size of only the touch region or the region with hertzian stress will change. This can be calculated in the simulation, for example, using a finite element method.

The contact region or region with hertzian stress between the first contact surface 28 and the second contact surface 48 therefore has a form which is symmetrical with respect to the axis of symmetry or optical axis of the lens 20. In the cross-sectional view shown in fig. 4, the touch area is point-like (in the case of an ideal rigid lens 20 and an ideal rigid mount 40). In view of the small deformation of the lens 20 and/or the mount 40, in practice the contact area or area with hertzian stress between the first contact surface 28 and the second contact surface 48 has the form of an annular funnel-shaped section or a lateral surface of a truncated cone. The cross section parallel to the optical axis of the touch region or the region with hertzian stress is then in the form of a line.

If an intermediate layer and/or adhesive is arranged between the first contact surface 28 and the second contact surface 48, the two contact surfaces 28, 48 do not immediately/directly touch each other. In the presence of the intermediate layer or adhesive, the areas that the two contact surfaces 28, 48 would touch if the intermediate layer were not present would be pressed against each other.

The radii of curvature of the first contact surface 28 and the second contact surface 48 may be determined or optimized in a simulation (e.g., using a finite element method) in such a way that, under the pressures expected in an underwater environment, the mechanical stresses are limited to the extent that the lens or optical system can withstand these stresses without damage. As a result, the lens 20 or the optical system 10 can also withstand particularly high pressures.

A seal is disposed between the side 27 and the mount 40. The seal 30 seals in a watertight manner the area between the side 27 or outer cylinder and the mounting 40. This reliably prevents water from entering the region between the first contact surface 28 and the second contact surface 48 or between the side surface 27 and the mounting socket 40.

The mount 40 has an undercut 42 or recess or constriction extending around the optical axis 29 of the lens 20. Flush with the undercut 42, the diameter of the mount 40 perpendicular to the optical axis 29 of the lens 20 is smaller than in the remaining area of the mount 40. Undercut 42 or undercut face 43 is in fluid connection with ambient environment 50. This means that, for example in an underwater environment, water at the same pressure as the water pressure on the outer surface 24 of the lens 20 and the outside of the mount is located in the undercut 42. As a result, bending moments in the region of the first contact face 28 and the second contact face 48 are minimized by the short, direct force path, since the water in the undercut 42 presses as it were against the water on the edge region 70 of the mount 40 adjacent to the lens 20. This minimizes or even prevents deformation of the second contact surface 48. This therefore prevents the touch area from varying. In other words, the outer face of the housing or mount 40 and the face 43 of the undercut 42 are subjected to the same level of pressure as the undercut 42. Thus, in the absence of a bending moment in the edge region of the mounting 40, there is a short, direct force flow. As a result, bending loads on the mount 40 are minimized in the area of the first and second contact surfaces 28, 48.

Flush with the undercut 42, the diameter of the mount 40 perpendicular to the optical axis 29 of the lens 20 (the optical axis 29 extending from top to bottom in fig. 3, or vice versa) substantially corresponds to the diameter of the lens 20 perpendicular to the optical axis 29 of the lens 20. As a result, bending loads and resulting deformation of a portion of mount 40 in the region of second contact surface 48 are minimized. In an underwater environment, the water pressure in the undercut 42 presses against the water on the portion or edge area 70 of the mount 40 that is flush with the outer surface 24 of the lens 20 (in fig. 3, the height extends from top to bottom, or vice versa). Thus, the first contact surface 28 and the second contact surface 48 are not subjected to bending moments.

The optical system 10 includes additional optical elements (e.g., additional lenses, CCD sensors, etc.) (not shown). The further optical element is fastened to the plane 71 of the mount 40 facing away from the lens 20 or the second contact surface 48 and is not immediately/directly fastened to a further part of the housing abutting against the mount 40. In case the lens 20 and the mount 40 are axially displaced with respect to the other part of the housing (i.e. in case of displacement along the optical axis 29) due to water pressure in the surrounding environment 50, the amount of displacement of the other optical element is the same as the amount of displacement of the lens 20. Thus, the distance between the optical elements of the optical system 10 remains constant, independent of the pressure in the surrounding environment 50. Therefore, the optical imaging quality of the optical system 10 remains unchanged.

In the figures, the housing or mounting 40 is only partially shown in each case.

List of reference numerals

10 optical system

20 lens

24 outer surface

26 inner surface

27 side surface

28 first contact surface

29 optical axis of lens

30 seal

35 screw ring

40 mounting seat

42 undercut

43 undercut face

48 second contact surface

50 surroundings

60 inner part

70 edge region of mounting seat

71 plane of the mounting.