Vehicle-mounted camera with surface heating function

Abstract

A camera (20) for a vehicle, in particular a commercial vehicle, comprises a housing (22) in or on which at least one optical element (24) is arranged, and a circuit board (10) with at least one image sensor (16) and a surface heating device (17) for heating the optical element (24).

Description

[0001] Cross - reference to related applications This application claims the priority of German Patent Application No. 10 2023 136 644.0, filed on December 22, 2023, the entire content of which is incorporated herein by reference. Technical field

[0002] The present invention relates to a camera with a surface heating function, particularly a camera for vehicles (such as commercial vehicles). Background art

[0003] For some time, camera systems and image capture systems have been used in vehicles, particularly commercial vehicles, as indirect viewing devices beside traditional rear - view mirrors, or as supplements to, or replacements for, these rear - view mirrors. A camera system typically has an image capture device, such as a camera that continuously captures data of the vehicle's surrounding environment (video). The (video) data captured by the image capture device is processed if necessary and then transmitted to a reproduction device located in the cab. The reproduction device permanently and real - time displays the (video) data to the driver and, if necessary, fades in additional information about the captured surrounding environment parts, such as collision alerts, distances, etc.

[0004] The cameras of camera systems are usually mounted on the outside of the vehicle. Therefore, the cameras are affected by any weather conditions at the vehicle's location. Especially in low - temperature situations, the image capture function of the camera may be affected due to frosting or condensation on the optical elements and the cover glass of the optical elements respectively. In addition, components that are repeatedly subjected to low temperatures may undergo material changes, thus accelerating wear.

[0005] To avoid the formation of frost or condensation on the optical elements of the camera, it is well - known to heat the camera. So far, heating elements (such as in the form of discrete resistors) have been arranged at specific positions on the circuit board, as disclosed in DE10 2013020 894 B3. However, these heating elements require a relatively large installation space in the camera. Therefore, either there is no installation space for other components in the camera, or if other components are installed, the overall volume of the camera increases, resulting in insufficient installation space required for the vehicle. Summary of the invention

[0006] Object of the invention In view of this, the object of the present invention is to provide a camera that, on the one hand, has a compact heating device that can reliably prevent the formation of frost or condensation, and on the other hand, has a very small installation space for the camera.

[0007] Summary The camera having the features described in claim 1 and the vehicle having the features described in claim 18 solve this problem. Preferred embodiments are given in the dependent claims.

[0008] The idea of the present invention is to provide a camera with a surface heating device for a vehicle, in particular a commercial vehicle. At least a part of the surface heating device is mounted on a circuit board on which an image sensor is also mounted. The surface heating device is made of a heat-conducting material and covers a certain area of the circuit board. Area refers to the current geometric shape, specifically, the part that extends in a planar manner in terms of length and width. In particular, the extensions of the surface heating device in the length and width directions are respectively many times larger than the extension in the thickness direction. In this regard, the extensions of the surface heating device in the length and width directions are determined such that when they are arranged on the circuit board, the plane they span is substantially parallel to the plane spanned by the length and width directions of the circuit board.

[0009] Through surface heating, since the heat-generating surface is larger than that of a traditional heating element, heat can be continuously input into the optical elements of the camera through a larger surface. At the same time, since the extension of the surface heating in the thickness direction is very small, only a small installation space is required in the longitudinal direction of the camera. The longitudinal direction of the camera refers to the direction in which the plug of the camera, one or more circuit boards, and the optical elements are arranged in a row.

[0010] For example, the surface heating device can be made of a metal sheet adhered to the circuit board. Additionally, the surface heating device can also be a thin metal layer sprayed, cast, vapor-deposited, or galvanized onto the circuit board. However, the surface heating device is preferably formed by conductor traces. The conductor traces can be made of copper material, aluminum, or copper alloy and aluminum alloy respectively. Alternatively, the conductor paths can also be made of other heat-conducting materials. To provide surface heating, the placement and laying of the conductor traces should be such that in the case of a single-segment conductor trace or in the case of multiple-segment conductor traces, the single-segment conductor traces are adjacent to each other on the circuit board. Adjacent means that there are no other elements between individual parts of the conductor traces, but the individual parts do not contact each other. For example, the conductor traces can be placed in a meandering manner. Currently, the meandering manner means that the conductor traces are arranged in a looped and wound manner respectively and change direction by approximately 180 degrees at two predetermined end positions. Therefore, the conductor traces have multiple conductor trace parts that are substantially parallel and do not interfere with each other. The advantage of the meandering arrangement is that compared with the spiral arrangement of the conductor path, the conductor path does not act as an antenna, and thus neither the electronic equipment of the camera nor the adjacent equipment will be interfered by the emitted interfering radiation, ensuring electromagnetic compatibility.

[0011] The heating power of the surface heating device formed by the conductor path depends on the cross-section and length of the conductor path and its arrangement, hereinafter referred to as the geometry of the surface heating device. A resistance can be generated through the specific thermal conductivity of the material used for the heat conduction path and the cross-section of the heat conduction path. Therefore, the resistance value can be calculated based on a predetermined current or voltage and a predetermined heating power, and then converted into a suitable conductor path geometry.

[0012] To effectively heat the optical element, the conductor path preferably extends partially around the image sensor. Alternatively, the conductor path can also completely surround the image sensor.

[0013] Since the heating of the camera is mainly to avoid the formation of frost or condensed water, the conductor path is preferably arranged on the side of the circuit board where the image sensor is located, that is, the side facing the optical element. Alternatively, the conductor path can also be arranged on the side opposite to the optical element, or the conductor path can be arranged on both sides of the circuit board.

[0014] According to a preferred embodiment, the outer boundary (outer boundary) of the conductor path is arranged in a plane, which is substantially consistent with the outer dimensions of the optical element. Therefore, it can be ensured that heat is effectively input into the optical element.

[0015] The conductor path is preferably arranged on a specific circuit board layer, preferably on the circuit board layer with the image sensor. Alternatively, the conductor path can also be arranged on another circuit board layer, such as an internal circuit board layer, or on the circuit board layer on the opposite side of the circuit board from the image sensor. Since the conductor path is only arranged on one circuit board layer, the conductor path is preferably in a two-dimensional planar shape, where the conductor path extends in the length and width directions but has almost no extension in the thickness direction.

[0016] In addition, the conductor path can also extend between multiple substantially parallel circuit board layers. This means that the conductor path is arranged such that in the top view of the circuit board, adjacent conductor path portions or conductor paths are arranged in a plane, but in the cross-sectional view of the circuit board, the conductor path switches between different parallel circuit board layers. In other words, in the cross-section of the circuit board, the conductor path exists on multiple circuit board layers, and they change and switch between the circuit board layers respectively. Therefore, the term "surface heating" must also be understood as an arrangement in which its individual parts are configured flatly, so that there is only a very limited extension in the thickness direction of the conductor path. However, in the cross-sectional view or side view, there is generally no flat configuration, but a configuration with different heights in the thickness direction of the circuit board, while maintaining a dimension with only a very slight extension in the thickness direction.

[0017] To avoid the image sensor from getting hot and thus generating image noise, the circuit board layer where the image sensor is located can be removed, and a clear path can be maintained between the image sensor and the conductor path. This means that there is no heat-conducting material between the image sensor and the conductor path. Therefore, the heat of the conductor path can be prevented from being transferred to the image sensor, thereby improving the reliability of the image sensor. If the space where the heat-conducting material is exposed is filled with heat-insulating material, this effect will be more obvious. In addition to removing the circuit board layer, a heat-insulating layer can also be provided between the image sensor and the heat-conducting path. The heat-insulating layer can be made of heat-insulating material for heat insulation, or can be made of heat-conducting material (such as the material of the conductor path) for storing heat and buffering heat respectively. In order to store and buffer sufficient heat respectively, the heat-insulating layer has a certain heat capacity. The term heat capacity currently refers to the ability to receive and store heat. For example, the heat-insulating layer can be configured as circular and annular respectively, with a certain extension in the longitudinal direction of the camera and the thickness direction of the conductor path, so that the heat-insulating layer has a certain material accumulation for storing thermal energy.

[0018] The camera preferably includes at least one second conductor path for selective control according to the heating power requirement. For example, the camera can have two conductor paths, which are configured as described above and can be arranged concentrically with each other or adjacent to the image sensor. During the heating operation, if a higher heating power is required, such as when the temperature is below freezing point, only one of the two conductor paths can be turned on and the other can be turned off. In addition to adjusting the heating power, the cross-section of the conductor path can also change along the extension direction of the conductor path. For example, the conductor channel can have a continuously changing cross-section or only a partial change in the cross-section.

[0019] To fix the optical element inside or on the camera housing, a heat-conducting element can be installed between the optical element and the housing. The heat-conducting element is preferably made of a casting compound to fix the optical element inside the housing and is made of a heat-conducting material. Therefore, the heat of the heat-conducting path can not only be directly introduced into the optical element, but also be indirectly introduced into the optical element through the casting compound, first introducing the heat into the camera housing and then into the optical element through the camera housing. In this way, the optical element can be heated more effectively and quickly.

[0020] In addition, the optical element can also be fixed on the circuit board by an adhesive. The adhesive is preferably made of a heat-conducting material to ensure reliable heat conduction from the conductor path to the optical element.

[0021] The camera preferably includes at least one temperature sensor for adjusting the heating capacity and / or heating time. The temperature sensor is used to detect the temperature state inside the camera housing and / or on the optical element, and these temperature states require adjusting the heating power and / or heating time. For this purpose, the sensor is preferably installed inside the camera housing, for example, embedded in a casting compound and / or adhesive, and preferably at or near the optical element. If the temperature sensor detects that the temperature inside the camera housing exceeds a specific predetermined value, this result can be transmitted to the regulating unit through the central electronic control unit (ECU), thereby reducing or turning off the heating power. Conversely, if the temperature sensor detects that the temperature inside the camera housing is lower than the predetermined temperature threshold, the regulating device can also turn on or increase the heating power. In addition, the user (such as the vehicle driver) can also initiate or select to initiate the monitoring of the temperature inside the camera housing. For this purpose, a user interface / user knob can be provided inside the vehicle, such as a user interface with an on / off switch, through which the user can initiate or stop the surface heating operation. Additionally, the temperature inside the camera housing can also be controlled by presetting the heating time.

[0022] In principle, the operation of the surface heating device can be connected to a regulating device through the ECU. The temperature sensor detects and reports the temperature value. If the temperature exceeds or is lower than the specified temperature value, the surface heating device is operated or no longer operated. Additionally, if the user cannot receive a good enough camera image in a cold outdoor environment, resulting in condensation or frost, the user can also operate the surface heating device, for example, through certain operating elements provided for this purpose inside the vehicle passenger compartment.

[0023] In addition to at least one temperature sensor, a current sensor can also be provided to detect the current intensity in the conductor path and, when the current intensity in the conductor path exceeds the allowable value or is lower than the required value, adjust the heating power and heating time through the regulating device. The current sensor can be installed inside the thermal insulation layer or on the circuit board. Here, the user can also manually set the heating power and heating time according to the current current intensity. For this purpose, the user can obtain the current current intensity and make corresponding adjustments. If the user makes an adverse adjustment to the heating, the control unit can override the user's input to avoid damaging the surface heating device and the camera.

[0024] At least one conductor path is preferably used not only for heating the optical element but also as a power supply line for components (such as image sensors) on the circuit board. Since the conductor path is used as a power supply line at the same time, a voltage drop will occur, and this must be taken into account when designing the conductor path.

[0025] All the above features can be combined in any possible way. Description of the Drawings

[0026] In the following, the present invention will be illustrated with reference to the accompanying drawings, in which: Figure 1 shows a longitudinal cross-section of a camera according to the present invention. According to the first embodiment, the surface of the camera is heated; Figure 2 shows a perspective view of a circuit board with conductor paths and optical elements; Figure 3 shows a top view of a circuit board with conductor paths, an image sensor, and a heat-insulating box; Figure 4 shows a perspective view of a circuit board with surface heating according to a second embodiment. Detailed Description of the Invention

[0027] Figure 1 shows a longitudinal cross-section of a camera 20 for a vehicle, the central axis of which is a-a'. The camera 20 has a housing 22. Inside the camera 22, an optical element 24 and a plurality of circuit boards 10 are arranged. The optical element 24 includes an objective lens / lens and a cover glass for protecting the lens. On the circuit board 10 beside the optical element 24, an image sensor 16 is mounted in the middle on the side facing the optical element 24 for recording images of the vehicle's surrounding environment. On the other side of the circuit board 10, that is, the side away from the optical element 24, electrical components required for performing the camera function are arranged. Optionally or additionally, the electrical components 14 are arranged on the side of the circuit board 10 facing the optical element 24. On the circuit board farthest from the optical element 24, there is a connector 30 for powering the camera and transmitting data. The circuit boards are conductively connected (not shown). The direction of the longitudinal axis a-a' in which the circuit boards, the image sensor 16, and the optical element 24 are arranged in sequence is currently referred to as the longitudinal direction.

[0028] Around the image sensor 16, that is, on the side of the circuit board 10 facing the optical element 24, there is a surface heating device 17, which is configured / formed as a conductor path 18. The outer dimensions of the conductor channel 18 are substantially the same as the outer dimensions of the surface of the optical element 24 facing the circuit board 10.

[0029] The optical element 24 is connected to the housing 22 and the circuit board 10 by a potting compound 28. The potting compound 28 is made of a thermally conductive material, such as a polyurethane base.

[0030] Figure 2 shows a perspective view of the circuit board 10 with the optical element 24. As Figure 2 shown, the end face of the optical element 24 facing the circuit board 10 is connected to the circuit board 10, especially the conductor path 18, by an adhesive 26 (such as super glue, two-component adhesive, etc.). Like the potting compound 28, the adhesive 26 is made of a thermally conductive material. FromFigure 2 It can be further seen that the conductor path 18 is arranged in a meandering manner around the image sensor 16 ( Figure 2 not shown in the figure), where specific windings and conductor path portions change their running direction by approximately 180 degrees at certain positions relative to the image sensor 16.

[0031] Figure 3 is shown Figure 1 a top view of the circuit board 10 in the figure. As Figure 3 shown, the image sensor 16 is generally located in the middle of the circuit board 10. However, the position of the image sensor 16 on the circuit board 10 can also be off - center. In principle, it must always be ensured that the optical element 24 can at least partially display and record images of the surroundings of the vehicle on the image sensor 16 respectively. That is to say, the optical element 24 does not necessarily have to be completely above the image sensor 16. Around the image sensor 16, a conductor path 18 is arranged. The conductor path 18 is arranged in a meandering manner around the image sensor 16 to avoid the conductor path 18 generating an antenna effect. The terminal 19 of the conductor path 18 is also provided on the circuit board 10 and is conductively connected to a power source (not shown). The image sensor 16 and the conductor path 18 are respectively mounted and arranged on the circuit board layer 12. The circuit board layer 12 is made of a heat - conductive metal (such as copper) to form a copper layer.

[0032] Between the image sensor 16 and the conductor path 18, a heat - insulating box layer 13 is provided. The heat - insulating layer 13 is configured as a closed fence, for example, annular, and completely surrounds the image sensor 16. The heat - insulating layer 13 can be made of a heat - insulating material or can be made of a metal, such as the same metal as the circuit board layer 12. In addition to the heat - insulating layer 13, the circuit board layer 12 between the image sensor 16 and the conductor path 18 can also be omitted. In this way, in addition to the heat - insulating layer 13, the heat of the conductor path 18 can be prevented from being transferred to the image sensor 16 through the circuit board layer 12.

[0033] For the heating of the camera 20, the conductor path 18 is energized, so that the conductor path 18 is heated. Since the spatial distance between the conductor path 18 and the optical element 24 is very close, the heat of the conductor path 18 is transferred to the optical element 24 through heat convection in the air. In addition, the thermal energy of the conductor path 18 is directly transferred to the optical element 24 through a thermally conductive adhesive 26, that is, from the conductor path 18 to the optical element 24 without any other elements except the adhesive 26. In addition, the heat of the conductor path 18 is also conducted from the thermally conductive potting compound 28 to the housing 22 and is conducted from the housing 22 to the optical element through heat convection in the air. In this way, the formation of frost or condensate on the optical element can be avoided, or the already formed frost layer or condensate can be removed.

[0034] It can be imagined that the current intensity or voltage flowing through the conductor will vary according to the expected heating power. In addition, in order to change the heating power, it is conceivable to provide not only one conductor path 18 on the circuit board 10, but also multiple conductor paths 18, which can be operated individually or jointly. In addition, it is conceivable that the cross-section of the conductor path 18 is not the same throughout its entire extension, and the cross-section can vary. For example, the conductor path 18 can have a continuously varying cross-section, or only vary in cross-section in segments. Generally speaking, the smaller the cross-section and the longer the conductor path, the greater the resistance, and vice versa. Therefore, the cross-section and length of the conductor path 18 can be calculated based on the required heating power, the specified current intensity or voltage, and the specific thermal conductivity of the material selected for the conductor path 18.

[0035] The heat insulation layer 13 is a protective ring that can prevent the heat of the conductor path 18 from being transferred to the image sensor 16. The heat insulation layer 13 is made of heat-insulating material and isolates the image sensor 16 from the conductor path 18, thus preventing heat from being transferred to the image sensor 16. Or the heat insulation box 13 is made of heat-conducting material and stores the heat of the conductor path 18, so that the heat will not be transferred to the image sensor 16, or will only be transferred to the image sensor 16 after a certain period of time. The circuit board layer 12 between the image sensor 16 and the conductor path 18 can be omitted and kept unobstructed respectively, so as to further achieve the heat insulation effect. Omitting the circuit board layer 12 between the image sensor 16 and the conductor path 18 may also be a single measure for heat insulation of the image sensor 16 (that is, no heat insulation layer 13 is provided).

[0036] Figure 4 A perspective view of the circuit board 10 is shown, in which the conductor path 18 is arranged not only on the circuit board layer 12, but also across multiple circuit board layers.

[0037] In Figure 4 In the illustrated embodiment, the surface heating device 17 configured as the conductor path 18 is basically composed of two conductor path portions 18a and 18b. The first conductor path portion 18a runs on the first circuit board layer 12a, while the second conductor path portion 18b runs on the second circuit board layer 12b, and the second circuit board layer 12b is substantially parallel to the first circuit board layer (not shown in the figure). The conductor path portions 18a and 18b are electrically connected to each other through the conductor path network 18c. Since the conductor path network 18c establishes contact between the first conductor path portion 18a located on the first circuit board layer 12a and the second conductor path portion 18b located on the second circuit board layer 12b, the conductor path web 18c extends in a farther spatial direction, and the conductor path 18 is three-dimensionally configured at the position of the conductor path network 18c. However, in principle, the conductor path 18 passing through the conductor path portions 18a and 18b is mainly two-dimensionally configured, and therefore, the wide portion is also two-dimensionally configured.

[0038] Although Figure 4 it is shown that the two conductor path portions 18a and 18b substantially completely coincide and respectively form the same conductor path, it is also possible that the conductor path portions 18a and 18b do form the same conductor path in terms of planar extension, but deviate from the longitudinal direction of the camera in the lateral direction. Additionally, it is also conceivable that the conductor path portions 18a and 18b are different from each other in terms of planar extension. For example, the conductor path portion 18a close to the optical element 24 is larger in terms of planar extension than the conductor path portion 18b far from the optical element 24. The cross-sections and materials of the conductor path portions 18a and 18b may also be different. Appropriate changes in the cross-section and / or material may occur in the conductor path network 18c, but may also occur at any other location of the conductor path portions 18a and 18b.

[0039] Reference List 10 Circuit board 12, 12a, 12b Circuit board layers 13 Thermal insulation layer 14 Electrical components 16 Image sensor 17 Surface heating device 18 Conductor path 18a, 18b Conductor path portions 19 Power connector 20 Camera 22 Housing 24 Optical element 26 Adhesive 28 Casting compound 30 Connector a-a' Central axis

Claims

1. A camera (20) for a vehicle, in particular a commercial vehicle, comprising: A housing (22), at least one optical element (24) arranged in or on the housing (22), and a circuit board (10) with at least one image sensor (16) and a surface heating device (17) for heating the optical element (24).

2. The camera head (20) according to claim 1, wherein the surface heating device (17) is formed by at least one conductor path (18), wherein a conductor path section of the conductor path (18) is arranged on the circuit board (10) to form a planar arrangement.

3. The camera (20) according to claim 2, wherein the conductor path (18) is arranged in a meandering manner.

4. The camera (20) according to claim 2 or 3, wherein the conductor path (18) is arranged at least partially around the image sensor (16).

5. The camera (20) according to claim 2 or 3, wherein the conductor path (18) is arranged on a side of the circuit board (10) facing the optical element (24).

6. The camera (20) according to claim 2 or 3, wherein the outer boundary of the conductor path (18) on the circuit board is substantially consistent with the outer boundary of the surface of the optical element (24), and the optical element (24) faces the conductor path (18).

7. The camera head (20) according to claim 2 or 3, wherein the conductor path (18) is arranged on a circuit board layer (12) of the circuit board (10).

8. The camera (20) of claim 7, wherein the conductor path (18) has a substantially two-dimensional shape.

9. The camera head (20) according to claim 2 or 3, wherein the conductor path (18) extends through a plurality of circuit board layers (12), the circuit board layers (12) being substantially parallel to one another.

10. The camera (20) according to claim 9, wherein the conductor path (18) has a three-dimensional shape.

11. The camera head (20) according to claim 5, wherein the circuit board layer (12) remains unobstructed in an area between the image sensor (16) and the conductor path (18).

12. The camera (20) according to claim 2, wherein a heat insulating layer (13) is provided between the image sensor (16) and the conductor path (18).

13. The camera head (20) according to claim 12, wherein the heat insulating layer (13) is made of a heat conductive material and has heat capacity.

14. The camera head (20) according to claim 2, comprising at least one second conductor path (18) for selective control according to heating power requirements.

15. The camera (20) of claim 1, further comprising a thermally conductive potting compound (28) disposed between the circuit board (10), the housing (22), and the optical element (24).

16. The camera head (20) according to claim 1, further comprising at least one temperature sensor for detecting the temperature inside the housing (22) to adjust the heating power and / or the heating time.

17. The camera (20) according to claim 2, wherein at least one conductor path (18) can be used as a power supply line for the image sensor (16) and / or electrical components (14) on the circuit board (10).

18. A vehicle having a camera (20) according to claim 1.

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