Housing device for an optical sensor

Abstract

Housing device for an optical sensor (2), in particular a vehicle camera, comprising at least one basic housing unit (3), at least one optically transparent front element (4) arranged on the basic housing unit (3), and at least one membrane unit (5) which is provided to seal the front element (4) against the basic housing unit (3) in a liquid-tight manner, and which is designed to be vapor-permeable for dehumidifying an interior space (6) bounded by the basic housing unit (3) and the front element (4).

Description

[0001] The invention relates to a housing device for an optical sensor. Furthermore, the invention relates to a corresponding optical sensor, in particular a vehicle camera, and to a vehicle, in particular an automated guided vehicle. The invention also relates to a method for dehumidifying a corresponding housing device.

[0002] Housing devices for optical sensors are known in the prior art. These housing devices typically have seals, such as O-rings, that make them watertight. Should moisture nevertheless penetrate the interior of such a housing device, for example during a manufacturing process, it cannot escape due to the seals and thus negatively affect the function of the optical sensor.

[0003] DE 10 2011 014 991 A1 discloses a camera comprising a housing, an optical system, and an electrical image sensor, particularly for exterior applications in motor vehicles. The system includes means for generating air convection within the optical system due to the heating of the air in the housing by the image sensor. These means preferably comprise a number of channels within the optical system to prevent undesirable effects from moisture penetrating the camera or the housing.

[0004] DE 10 2014 113 992 A1 discloses a housing arrangement for a motor vehicle camera, comprising a camera housing for mounting the camera and a connector housing for protecting an electrical connection element of the motor vehicle and / or the camera. The camera housing is connected to the connector housing in such a way that the connector housing covers at least part of the rear of the camera housing. The housing arrangement includes a ventilation element to prevent moisture from entering the camera housing and / or the connector housing. The camera housing has a first ventilation opening in its rear, and the ventilation element is positioned between the rear of the camera housing and the connector housing in such a way that the ventilation element completely covers the first ventilation opening.

[0005] A housing device for an optical sensor, in particular a vehicle camera, is proposed. The housing device comprises at least one basic housing unit. The housing device comprises at least one optically transparent front element arranged on the basic housing unit. The housing device comprises at least one membrane unit designed to create a liquid-tight seal between the front element and the basic housing unit. The membrane unit is vapor-permeable to allow dehumidification of an interior space bounded by the basic housing unit and the front element.

[0006] Preferably, the optical sensor comprises the housing. The optical sensor can be configured, in particular, as a camera, especially a vehicle camera, as a lidar (light detection and ranging) sensor, or as another optical sensor that would appear suitable to a person skilled in the art. Preferably, the optical sensor is intended for use in a vehicle. "Intended" is understood to mean, in particular, specifically programmed, specially equipped, and / or specially designed. The phrase "an object is intended for a function" is understood to mean, in particular, that the object performs the function in at least one operating state.

[0007] The housing device, in particular the basic housing unit, is preferably designed to at least partially enclose, and especially to accommodate, components of the optical sensor. In particular, the housing device is designed to protect the components from environmental influences. The components may, in particular, comprise an optical unit, a scanner unit, an image sensor, a laser source, or the like. The basic housing unit is preferably designed as an optical holder, in particular as a lens holder. In particular, the basic housing unit may be designed to hold lenses of an optical unit, in particular a lens, of the optical sensor.

[0008] The front element can be configured, in particular, as a front lens of the optical unit. Alternatively, it is conceivable that the front element is configured as a windscreen, a protective glass, or the like. The optically transparent front element is specifically designed to transmit radiation. In particular, the front element can be designed to transmit radiation to an image sensor, to transmit radiation from a laser source, or the like. The front element is specifically arranged on an outer surface of the optical sensor. In particular, the front element is arranged on an outer surface of the optical sensor when mounted on a vehicle. Preferably, the front element is fixed to the housing base unit, for example, screwed to the housing base unit and / or clamped to the housing base unit by means of a cover element of the housing device.

[0009] The membrane unit is arranged, at least partially, between the front element and the housing base unit. In particular, the membrane unit rests against the front element and the housing base unit. The membrane unit can, for example, be welded, bonded, or similarly bonded to the front element and the housing base unit. Preferably, the membrane unit is liquid-tight, and in particular, waterproof. In particular, the membrane unit, and especially the housing assembly, can meet protection class IP6K9K. The membrane unit can, in particular, be made at least partially of polytetrafluoroethylene, polyurethane, a polyether ester, or another material that would appear suitable to a person skilled in the art. Preferably, the membrane unit can be coated or impregnated on a side facing away from the interior with a liquid-repellent, and in particular water-repellent, material.In particular, the membrane unit is designed to prevent liquids, especially water, from penetrating the interior.

[0010] In particular, indoor humidity can reduce the optical transparency of the front element and / or other optical elements of the optical sensor. Specifically, the humidity can condense on the front element and / or other optical elements, forming liquid droplets. This reduction in optical transparency can impair the functionality of the optical sensor. The humidity can cause scattering effects (glare and / or flare), where radiation transmitted and / or to be transmitted by the front element is scattered, leading to reduced detection performance and / or a lower signal-to-noise ratio of the optical sensor. Furthermore, the humidity can damage components of the optical sensor.Moisture may have entered the interior, for example, during a manufacturing process of the housing device and / or in an unplugged state through a connector, and / or, in particular over a longer operating period, may have entered the interior, especially at points of the basic housing unit that are not sealed by the membrane unit.

[0011] The membrane unit is preferably designed for dehumidifying the housing. In particular, the membrane unit is designed to allow moisture in the form of vapor to escape from the interior. Preferably, the membrane unit is vapor-permeable, especially permeable to water vapor. In particular, the membrane unit has pores that are smaller than liquid droplets, especially water droplets, so that the liquid cannot pass through the membrane unit. In particular, the pores are larger than vapor molecules, especially water vapor molecules, so that the vapor can pass through the membrane unit. The moisture in the interior can be evaporated, in particular by heating, for example, by an increase in ambient temperature or by a heating element in the housing.

[0012] The design of the housing device according to the invention advantageously enables dehumidification of the housing device while simultaneously protecting it from the ingress of liquid. Advantageously, high performance of the optical sensor can be achieved. Advantageously, a particularly compact housing device with moisture protection can be provided.

[0013] Furthermore, it is proposed that the membrane unit encloses the front element along its circumference. In particular, the membrane unit encloses the front element along its entire circumference. The front element, especially a front element designed as a front lens, can have a circular circumference. In particular, the membrane unit can be annular. In particular, the membrane unit has a larger diameter than the front element. In particular, the housing base unit can be cylindrical, with the front element forming at least a partial base of the cylinder. The front element, especially a front element designed as a front window, can have a rectangular circumference. In particular, the membrane unit can enclose the front element in a frame-like manner.In particular, the membrane unit encloses an optical axis of the front element. This advantageously enables a particularly effective seal between the front element and the housing base unit.

[0014] Furthermore, it is proposed that the membrane unit exhibit hygroscopic properties. In particular, the membrane unit exhibits hygroscopic properties at least on one side facing the interior. Specifically, the membrane unit is designed to attract moisture from the interior and, in particular, to bind it, at least partially. Advantageously, moisture from the interior can be concentrated at a single outlet point and effectively removed.

[0015] It is further proposed that the housing device includes at least one heating unit arranged in the interior, which is designed to evaporate the liquid from the interior to facilitate the transport of liquid through the membrane unit and out of the interior. The heating unit can be designed, in particular, as a heating film, a heating wire, or the like. The heating unit is specifically designed to convert electrical energy into heat. In particular, the heating unit generates more heat the greater the electric current through the heating unit. Preferably, the heating unit is designed to heat the interior, especially the moisture present in the interior, particularly at least to a temperature at which the moisture changes from a liquid phase to a vapor phase. Preferably, the heating unit is arranged in the immediate vicinity of the membrane unit. Preferably, the housing device comprises a single heating unit.Alternatively, the housing could incorporate multiple heating units, particularly those with different functions. The heating unit could be controlled based on temperature, humidity, continuous operation, intermittent operation, or similar settings. Advantageously, moisture in the interior could be evaporated to enable efficient dehumidification.

[0016] Furthermore, it is proposed that the heating unit be in direct contact with the front element and be designed to heat the front element by heat conduction. Preferably, the heating unit is designed differently from a coating of the front element. Preferably, in addition to evaporating liquid, the heating unit is also designed to heat the front element. In particular, the heating unit is designed to heat the front element to prevent icing and / or condensation on the front element. Preferably, the heating unit is designed to maintain the front element at a constant temperature above 10°C. In particular, during heating of the front element, the heating unit automatically evaporates any liquid present in the interior and transports it out of the interior, especially via the membrane unit.The heating unit is preferably arranged, at least partially, between the front element and the housing base unit, and in particular fixed in place. Advantageously, a heating unit can be provided that can perform several functions simultaneously.

[0017] Furthermore, it is proposed that the heating unit be annular in shape. In particular, the heating unit is designed in the form of a closed circular ring. Preferably, the heating unit encloses the optical axis of the front element. In an alternative embodiment, it is conceivable that the heating unit be rectangular, particularly frame-like. Advantageously, this allows for uniform heating of the front element.

[0018] Furthermore, it is proposed that the outer diameter of the heating unit corresponds to the outer diameter of the front element. In particular, the heating unit is positioned against the front element in such a way that it is flush with the front element. The outer diameters extend perpendicular to the optical axis of the front element. In particular, an inner diameter of the heating unit defines a portion of the front element through which radiation can be transmitted. Preferably, a principal plane of extension of the heating unit extends perpendicular to the optical axis of the front element. A "principal plane of extension" of an object is understood to be, in particular, a plane that is parallel to a major face of the smallest imaginary cuboid or square that just completely encloses the object, and in particular, that passes through the center of the cuboid or square.Advantageously, a maximum temperature of the heating unit can be provided in the immediate vicinity of the membrane unit, enabling particularly effective dehumidification.

[0019] It is further proposed that the housing device includes at least one electrical contact element for connecting the heating unit to an external electronic unit, wherein the electrical contact element extends from the housing base unit at an end facing away from the front element. The contact element is specifically designed to transmit electrical energy from the electronic unit to the heating unit. Preferably, the optical sensor includes the electronic unit. Alternatively, it is conceivable that the vehicle includes the electronic unit. The electronic unit is, in particular, arranged outside the housing device. The electrical contact element can, in particular, be configured as a cable, especially a ribbon cable, as a wire, or as another electrical contact element that would appear suitable to a person skilled in the art.Preferably, the electrical contact element is electrically connected to the heating unit and the electronic unit, in particular by soldering, plugging, or the like. Preferably, the electrical contact element extends at least partially within the interior, in particular parallel to the optical axis of the front element. Preferably, the housing base unit is sealed liquid-tight at the point where the electrical contact element emerges. Advantageously, controlled operation of the heating unit can be enabled.

[0020] Furthermore, an optical sensor, in particular a vehicle camera, is proposed. The optical sensor comprises at least one housing device according to the invention. The optical sensor is preferably intended for monitoring the environment of a vehicle, in particular for the realization of at least partially autonomous driving functions of the vehicle. Advantageously, a particularly compact optical sensor with high performance and moisture protection can be provided.

[0021] Furthermore, a vehicle, in particular an automated vehicle, is proposed. The vehicle comprises at least one housing device or at least one optical sensor according to the invention. The vehicle may, in particular, also comprise a plurality of housing devices or optical sensors. An "automated vehicle" is understood to mean, in particular, a vehicle with one of the automation levels 1 to 5 of standard SAE J3016. In particular, the automated vehicle has technical equipment required for these automation levels. The technical equipment includes, in particular, environmental perception sensors, such as at least one optical sensor according to the invention, in particular a camera or a lidar sensor, radar sensors and / or acoustic sensors, control units, or the like. Preferably, the automated vehicle is designed as a land vehicle.The automated vehicle can be configured, in particular, as a passenger car, preferably as a passenger transport vehicle, as a truck, as a construction vehicle, as an agricultural vehicle, or as any other vehicle that would appear suitable to a person skilled in the art. Alternatively, the automated vehicle can also be configured as an aircraft, for example, as a drone, as an airplane, as a helicopter, as a vertical take-off and landing aircraft, or the like, or as a watercraft, for example, as a ship or a boat. In particular, an automated vehicle requires a consistently high performance of optical sensors for at least semi-autonomous operation, which can be made possible, in particular, by the design according to the invention. A vehicle that is weather-independent, especially humidity-independent, and advantageously safe for traffic and occupants can be provided.

[0022] Furthermore, a method for dehumidifying a housing device according to the invention is proposed. Liquid present in an interior space bounded by at least one housing base unit of the housing device and at least one optically transparent front element of the housing device is evaporated and transported out of the interior space by at least one vapor-permeable membrane unit of the housing device, which seals the front element against the housing base unit in a liquid-tight manner. Advantageously, an effective and efficient method for dehumidifying the housing device can be provided.

[0023] The invention is illustrated by an exemplary embodiment in the following figures. They show: Fig. 1 a vehicle according to the invention in a schematic representation, Fig. 2 a sectional view of a housing device according to the invention of the vehicle according to the invention Fig. 1 in a schematic representation, Fig. 3 a heating unit of the housing device according to the invention Fig. 2 in a schematic perspective representation and Fig. 4 a flowchart of a method according to the invention in a schematic representation.

[0024] Fig. Figure 1 shows a vehicle 12 in a schematic representation. The vehicle 12 is designed as an example of an automated vehicle. The vehicle 12 is designed as an example of a land vehicle, in particular a passenger car. The vehicle 12 comprises at least one optical sensor 2. The optical sensor 2 is designed as an example of a vehicle camera. The optical sensor 2 is intended to monitor the environment of the vehicle 12, in particular for the realization of at least partially autonomous driving functions of the vehicle 12. The optical sensor 2 comprises at least one housing device 1 (see Figure 1). Fig. 2).

[0025] Fig. Figure 2 shows a sectional view of the housing device 1 of the vehicle 12. Fig. Figure 1 is shown schematically. The housing device 1 comprises at least one basic housing unit 3. The housing device 1 comprises at least one optically transparent front element 4, which is arranged on the basic housing unit 3. The housing device 1 comprises at least one membrane unit 5, which is designed to seal the front element 4 against the basic housing unit 3 in a liquid-tight manner. The membrane unit 5 is designed to be vapor-permeable for dehumidifying an interior space 6 bounded by the basic housing unit 3 and the front element. In the present embodiment, the front element 4 is designed by way of example as a front lens. The optically transparent front element 4 is designed to transmit radiation. The front element 4 is designed to transmit radiation to an image sensor of the optical sensor 2 (not shown here).The front element 4 is clamped to the housing base unit 3 by means of a cover element 13 of the housing device 1.

[0026] The membrane unit 5 is arranged, at least partially, between the front element 4 and the housing base unit 3. The membrane unit 5 rests against the front element 4 and the housing base unit 3. The membrane unit 5 is designed to be liquid-tight, in particular watertight. The membrane unit 5 is intended to prevent liquids, in particular water, from penetrating the interior 6. The membrane unit 5 is intended to dehumidify the housing device 1. The membrane unit 5 is intended to allow moisture in the form of vapor to escape from the interior 6. The membrane unit 5 is designed to be vapor-permeable, in particular water vapor-permeable.

[0027] The membrane unit 5 surrounds the front element 4 along its circumference. The front element 4 has a circular circumference. The membrane unit 5 is annular in shape. The membrane unit 5 has a larger diameter than the front element 4. The housing base unit 3 is cylindrical in shape, with the front element 4 forming at least part of the base of the cylinder. The membrane unit 5 surrounds an optical axis 14 of the front element 4.

[0028] The membrane unit 5 has hygroscopic properties. The membrane unit 5 has hygroscopic properties at least on one side facing the interior space 6. The membrane unit 5 is designed to attract moisture in the interior space 6 and to bind it, at least partially.

[0029] The housing device 1 comprises at least one heating unit 7 arranged in the interior 6. The heating unit 7 is designed to evaporate the liquid in order to transport it through the membrane unit 5 from the interior. In the present embodiment, the heating unit 7 is designed as a heating film. The heating unit 7 is designed to heat the interior 6, in particular the moisture present in the interior 6, especially at least to a temperature at which the moisture changes from a liquid phase to a vapor phase. The heating unit 7 is arranged in close proximity to the membrane unit 5. The housing device 1 comprises a single heating unit 7.

[0030] The heating unit 7 is in direct contact with the front element 4. The heating unit 7 is designed to heat the front element 4 by heat conduction. The heating unit 7 is designed to heat the front element 4 in order to prevent icing and / or condensation on the front element 4. During heating of the front element 4, the heating unit 7 automatically evaporates any liquid present in the interior 6 and, in particular, transports it out of the interior 6 by the membrane unit 5. The heating unit 7 is arranged, and in particular fixed, at least partially between the front element 4 and the housing base unit 3.

[0031] Heating unit 7 is annular in shape. Heating unit 7 is designed in the form of a closed circular ring (see figure). Fig. 3) The heating unit 7 surrounds the optical axis 14 of the front element 4. An outer diameter 8 of the heating unit 7 corresponds to an outer diameter 9 of the front element 7. In particular, the heating unit rests against the front element in such a way that it is flush with the front element. An inner diameter 15 of the heating unit 7 defines a portion of the front element 4 through which radiation can be transmitted. A principal extension plane 16 of the heating unit 7 extends perpendicular to the optical axis 14 of the front element 4.

[0032] The housing device 1 comprises at least one electrical contact element 10 for connecting the heating unit 7 to an external electronic unit (not shown here). The electrical contact element 10 extends from the housing base unit 3 at an end 11 facing away from the front element 4. In the present embodiment, the electrical contact element 11 is designed as a cable, in particular as a ribbon cable. The electrical contact element 10 extends at least partially within the interior 6, in particular parallel to the optical axis 14 of the front element 4.

[0033] Fig. Figure 3 shows the heating unit 7 of the housing device 1. Fig. Figure 2 shows a schematic perspective view. The electrical contact element 10 is electrically connected to the heating unit 7, in particular by soldering. The electrical contact element 10 has a plug contact 17 for electrical connection to the electronic unit. A temperature sensor 18 is arranged on the electrical contact element 10 in the immediate vicinity of the heating unit. In the present embodiment, the temperature sensor 18 is designed as an NTC (Negative Temperature Coefficient) resistor. The temperature sensor 18 is designed to detect the temperature of the heating unit 7. The electrical contact element 10 is designed to electrically connect the temperature sensor 18 to the electronic unit.

[0034] Fig.Figure 4 shows a schematic flowchart of a process for dehumidifying the housing device 1. In process step 19, the liquid present in the interior 6, bounded by the housing base unit 3 of the housing device 1 and the optically transparent front element 4 of the housing device 1, is evaporated. The liquid can be evaporated by the heating unit 7 and / or due to a high ambient temperature. In a further process step 20, the evaporated liquid is transported out of the interior 6 through the vapor-permeable membrane unit 5 of the housing device 1, which seals the front element 4 against the housing base unit 3 in a liquid-tight manner. Reference sign 1 Housing device 2 optical sensors 3 Housing base unit 4 Front element 5 Membrane unit 6 Interior 7 heating units 8 Outer diameter 9 Outer diameter 10 electrical contact element 11 End 12 vehicles 13 Cover element 14 optical axis 15 inner diameter 16 Main extent level 17 Plug contact 18 Temperature sensor 19th procedural step 20th process step

Claims

[1] Housing device for an optical sensor (2), in particular a vehicle camera, comprising at least one basic housing unit (3), at least one optically transparent front element (4) arranged on the basic housing unit (3), and at least one membrane unit (5) designed to seal the front element (4) against the basic housing unit (3) in a liquid-tight manner, and designed to be vapor-permeable for dehumidifying an interior space (6) bounded by the basic housing unit (3) and the front element (4). [2] Housing device according to claim 1, wherein the membrane unit (5) surrounds the front element (4) along a circumference of the front element (4). [3] Housing device according to claim 1 or 2, wherein the membrane unit (5) has hygroscopic properties. [4] Housing device according to one of the preceding claims, comprising at least one heating unit (7) arranged in the interior (6), which is designed to evaporate the liquid for the purpose of transporting liquid through the membrane unit (5) from the interior (6). [5] Housing device according to claim 4, wherein the heating unit (7) is in direct contact with the front element (4) and is designed to heat the front element (4) by heat conduction. [6] Housing device according to claim 4 or 5, wherein the heating unit (7) is annular in shape. [7] Housing device according to claim 6, wherein an outer diameter (8) of the heating unit (7) corresponds to an outer diameter (9) of the front element (4). [8] Housing device according to one of claims 4 to 7, comprising at least one electrical contact element (10) to connect the heating unit (7) to an external electronic unit, wherein the electrical contact element (10) is brought out of the housing base unit (3) at an end (11) of the housing base unit (3) facing away from the front element (4). [9] Optical sensor, in particular vehicle camera, comprising at least one housing device (1) according to any of the preceding claims. [10] Vehicle, in particular an automated vehicle, comprising at least one housing device (1) according to any one of claims 1 to 8 or at least one optical sensor (2) according to claim 9. [11] Method for dehumidifying a housing device (1) according to one of claims 1 to 8, wherein liquid present in an interior space (6) bounded by at least one basic housing unit (3) of the housing device (1) and at least one optically transparent front element (4) of the housing device (1) is evaporated and transported out of the interior space (6) by at least one vapor-permeable membrane unit (5) of the housing device (1), which seals the front element (4) against the basic housing unit (3) in a liquid-tight manner.

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