The invention relates to an automotive camera, a method for assembling such a camera and a vehicle comprising such a camera.

Cameras, which are designed to be arranged on motor vehicles, may be denoted as automotive cameras. Automotive cameras depicting an exterior environment of the motor vehicle are used for various driver assistance functions or other functions for partially or fully automatic driving of a motor vehicle. However, automotive cameras may also be employed for the capturing of an interior of the vehicle and may be arranged correspondingly. Thus, automotive cameras may be exposed to significant temperature fluctuations and/or other environmental conditions, including being hit by objects such as gravel and/or insects or the like while the vehicle is moving in the field. Moreover, automotive cameras are also exposed to mechanical stress due to vibrations while the vehicle is moving. Automotive cameras for motor vehicles should therefore be designed to operate as desired under vehicle operating conditions and to achieve sufficiently good image quality. The images may then be provided to driver assistance systems or other electronic vehicle guidance systems, which may use them as an input for driver assistance or for automatically guiding the vehicle.

An automotive camera of the above described type typically comprises one or more lenses, which are arranged inside a lens barrel. As the lenses are sensitive parts of the camera, they need to be protected, which can be done by placing a transparent protective cover in front of the lenses.

Protective lens covers are for example disclosed in documents DE 10 2016 105 569 A1 , KR 100 866 618 B1 or US 2019/030 25 76 A1 . The latter discloses a camera with a protective glass, which is retained on a lens support by a retaining cap. The retaining cap is connected to a tubular portion of the camera by a threaded connection.

The mechanical stress acting upon an automotive camera due to operating a vehicle carrying the camera in the field may result in loosening such a connection and in losing the protective cap. It is an objective of the present invention to provide an improved automotive camera of the above-described type, wherein reliable protection of the lenses of the camera is provided.

This objective is achieved by the respective subject matter of the independent claims. Further implementations and preferred embodiments are subject matter of the dependent claims.

A first aspect of the invention is directed to an automotive camera with a lens assembly. The lens assembly comprises a cylindrical lens barrel with at least one lens arranged therein and a lens opening for allowing light to travel through the lens barrel along an optical axis of the lens. Light may enter the lens barrel through the lens opening and travel in the lens barrel along an optical axis of the lens. The optical axis of the lens may coincide with a central longitudinal axis of the lens barrel and/or the lens assembly. After having passed the lens, the light may arrive at a circuit board of the automotive camera, which may carry an imager chip, where imager signals may be generated. The imager chip may provide a control unit of the camera with the information necessary to generate video data depending on the imager signals.

According to the invention, a transparent protective cover is arranged at the lens opening for protecting the at least one lens against an environmental influence from outside the automotive camera. The protective cover may contain silicone and/or germanium. The protective cover can be transparent or translucent for light within the visible spectrum. It can also be transparent for electromagnetic waves having wavelengths within the infrared (I R) spectrum and/or other value ranges depending on a field of application of the camera.

A fastening cap comprising a central opening and a fastening collar surrounding the central opening is put on or placed on the lens barrel at the lens opening to fasten the protective cover to the lens barrel. The fastening cap may be pinned up or pinned on the lens barrel or may be threaded on the lens barrel. The fastening collar may at least partially encompass or reach around an outer circumferential surface of the lens barrel. The fastening cap may contain a metal, such as aluminum or an aluminum alloy.

According to the invention, the fastening cap is locked to the lens barrel in a final fastening position by a locking mechanism, wherein the locking mechanism prevents the fastening cap from being moved out of the final fastening position. In other words, the locking mechanism fixes the fastening cap in the final fastening position. Preferably, the locking mechanism locks the fastening cap automatically to the lens barrel, once the final fastening position is reached. According to the invention, the locking mechanism prevents a movement of the fastening cap in any direction, once the final fastening position is reached. Preferably, the fastening cap can be removed from the lens barrel by unlocking the locking mechanism. In other words, the cap may be detachably locked to the lens barrel by the locking mechanism. Thus, the cap can be removed from the barrel in a nondestructive way.

Due to the described locking mechanism, the risk of losing the protective cover is reduced significantly. Thus, the lens of the automotive camera is reliably protected.

The invention also includes further embodiments that provide additional advantages.

According to an embodiment, the locking mechanism comprises a first recess formed in an outer circumferential surface of the lens barrel and a second recess formed in an inner circumferential surface of the fastening collar. In the final fastening position, the fastening collar is positioned relatively to the lens barrel, such that the first recess and the second recess overlap or coincide. Thus, the two recesses form a cavity, once the final fastening position is reached. A locking element of the locking mechanism is arranged inside the cavity for locking the fastening cap to the lens barrel. In other words, the final fastening position is predetermined or defined by the relative position of the fastening collar of the protective cap and the lens barrel with respect to each other. In the relative position, the recess formed in the outer circumferential surface of the lens barrel and the recess formed in the inner circumferential surface of the fastening collar coincide. Together, the two recesses form the cavity. The locking element can be arranged inside the cavity manually or automatically. Thus, a mechanically simple, yet reliable locking mechanism is provided.

According to a further embodiment, the locking mechanism comprises as a locking element a spring-loaded plunger. The spring-loaded plunger can be compressed and stored within the first or the second recess in a storing position, wherein in the storing position, its length is reduced with respect to its maximum length after complete decompression. Compression has to be carried out acting against the restoring force of the plunger-spring. In the storing position, a plunger head presses against either the inner circumferential surface of the fastening collar or against the outer circumferential surface of the lens barrel, depending on whether the plunger is stored within the first or the second recess, respectively. The plunger is designed to protrude into the cavity or move into the cavity, when the final fastening position is reached and the recesses overlap. The protrusion or movement is driven by decompression of the plunger due to the restoring force of its spring. Once the final fastening position is reached, the spring-loaded plunger protudes into the cavity, thus locking the fastening cap on the lens barrel. Thus, the fastening cap will be automatically secured in the final fastening position. In order to loosen the locking mechanism, the spring-loaded plunger can be compressed and pushed back into its storing position. To facilitate the pushing back of the plunger, the plunger can comprise a ramp shaped surface, wherein the inner circumferential surface of the fastening collar (or the outer circumferential surface of the lens barrel) can slide along the ramp shaped surface, thus pushing the plunger back into the storing position. Preferably, a necessary disassembly torque force will be smaller than a lens barrel adhesion shear force, which needs to be applied in order to loosen the lens barrel from an adjacent camera component.

According to a further embodiment, the second recess is formed as a through-hole breaking through the fastening collar, wherein in the final fastening position, the through- hole and the first recess overlap. Because the second recess is formed as a through-hole, the cavity opens to an area outside the lens barrel. In other words, the first recess and the through-hole can be accessed from outside the lens barrel. The locking mechanism comprises as a locking element a locking pin, which is designed to be arranged within the cavity, when the final fastening position is reached.

Preferably, the locking pin is formed as a locking screw. The locking screw can be screwed into the cavity. Preferably, the screw is formed as a headless screw or a set screw, such that it will not protrude from an outer circumferential surface of the fastening collar, when it is fully screwed into the cavity.

According to a further embodiment, a seal ring is arranged at a surface of the lens barrel facing the transparent protective cover. In the final fastening position, the transparent protective cover is pressed towards or against the seal ring by the fastening cap with a predetermined contact pressure. The seal ring can prevent a damage to the protective cover and/or to the lens by providing a spacer between the surface of the lens barrel facing the protective cover and the protective cover itself. In addition, the seal ring provides a sealing function. The fastening cap and the lens barrel may have a hard stop feature or similar to avoid over-compressing the seal ring. Preferably, the fastening cap is screwed or threaded on the lens opening of the lens barrel. This further facilitates the assembly of the automotive camera as a whole. Once, the final fastening position is reached, the above described recesses will overlap, such that the locking element of the locking mechanism can be placed inside the thus created cavity.

According to a further embodiment, the lens assembly is screwed and/or glued to a first opening of a housing of the automotive camera.

A further aspect of the invention is directed at a method for assembling an automotive camera of the described type. The camera comprises a lens assembly, wherein the lens assembly comprises a cylindrical lens barrel with at least one lens arranged therein and a lens opening for allowing light to travel through the lens barrel along an optical axis of the lens. A transparent protective cover is arranged at the lens opening for protecting the at least one lens against an environmental influence from outside the automotive camera. According to a step of the described method, a fastening cap comprising a central opening and a fastening collar surrounding the central opening is put on the lens barrel at the lens opening to fasten the protective cover to the lens barrel. Then, the fastening cap is locked to the lens barrel in a final fastening position by a locking mechanism. The locking mechanism prevents the fastening cap from being moved out of the final fastening position. In other words, the locking mechanism fixes the fastening cap in the final fastening position.

The transparent protective cover can be part of the fastening cap. Alternatively, it can be handled independently.

A further aspect of the invention is directed at a vehicle, comprising an automotive camera.

The advantages and preferred embodiments described for the automotive camera according to the invention also apply to the method according to the invention and vice versa.

The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations or embodiments. Implementations and feature combinations are also to be considered as disclosed, which thus do not comprise all of the features of the originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extent beyond or deviate from the feature combinations set out in the relations of the claims.

In the following, the invention will be explained in detail with reference to specific exemplary implementations and respective schematic drawings. In the drawings, identical or functionally identical elements may be denoted by the same reference signs. The description of identical or functionally identical elements is not necessarily repeated with respect to different figures.

In the figures,

Fig. 1 shows a schematic side view of an automotive camera,

Fig. 2 shows a detailed schematic perspective view of a lens barrel with a lens and a protective cover held by a fastening cap,

Fig. 3 shows a detailed schematic perspective view of a lens barrel with a seal ring and of a lens barrel with a fastening cap,

Fig. 4 shows a schematic cross-sectional view of a first locking mechanism,

Fig. 5 shows a schematic cross-sectional view of a second locking mechanism,

Fig. 6 shows a schematic view of a motor vehicle with several automotive cameras, and

Fig. 7 shows a schematic view of an exemplary implementation of a method for assembling an automotive camera according to the invention.

Fig. 1 shows a schematic side view of an automotive camera 10. The automotive camera 10 comprises a back housing 12, a front housing 14 and a lens assembly 16. Between the back housing 12 and the front housing 14, there may be a metal back plate 18. The front housing 14 may carry a printed circuit board (not shown) with an integrated imager chip. The metal back plate 18 can be sealed onto the front housing 14.

The automotive camera 10 can be a thermal infrared camera designed for automotive application. A lens field of view can vary depending on a customer requirement (current lens design can have 31 degrees field of view). During assembly of the automotive camera 10, the lens assembly 16 can be aligned with respect to the printed circuit board imager through a five-axis alignment procedure. An optical axis 20 of the lens assembly 16 can be aligned with a cylindrical axis of the cylindrical lens barrel 22 of the lens assembly 16. The automotive camera 10 can be connected to an image processing control unit (not shown) by means of a connecting interface 24.

Fig. 2 shows a schematic detailed perspective view of the lens assembly 16. The lens assembly 16 comprises the cylindrical lens barrel 22 and at least one lens 26 or lens glass 26 arranged therein. The optical axis 20 of the lens assembly 16 may coincide with an optical axis of the at least one lens glass 26. A transparent protective cover 28 is arranged on top of the lens 26 and fastened to the lens barrel 22 by a fastening cap 30. For better visibility, the transparent protective cover 28 is shown separately in Fig. 2. The fastening cap 30 comprises a central opening 32 and a fastening collar 34 surrounding the central opening 32.

Fig. 3 shows two further schematic detailed views of the lens assembly 16. On the left side of Fig. 3, the cylindrical lens barrel 22 is shown without the lens 26. Instead, a seal ring 36 is shown, which is arranged within a corresponding groove that is formed along an upper surface of the lens barrel 22. The protective cover 28 and the fastening cap 30 are shown in an explosive view. The lens barrel 22, the protective cover 28 and the fastening cap 30 are all centered on the optical axis 20.

In the assembled state, which is shown on the right side of Fig. 3, the transparent protective cover 28 is placed on top of the seal ring 36. The protective cover 28 is fastened to the lens barrel 22 by the fastening cap 30, which can be threaded on the lens barrel 22. A thread lock can be applied to the fastening cap 30 prior to the threading process. This can ensure that the fastening cap 30 will be fixed with the lens barrel 22 after the threading process and after the thread lock is cured. Fig. 4 shows a schematic detailed cross-sectional view of the lens assembly 16, wherein the fastening cap 30 is fastened to the lens barrel 22, thereby pressing the transparent protective cover 28 against the seal ring 36. The fastening cap 30 is locked to the lens barrel 22 in a final fastening position by a locking mechanism, wherein the locking mechanism comprises a first recess 38, which is formed in an outer circumferential surface 40 of the lens barrel 22. The locking mechanism further comprises a second recess 42, which is formed in an inner circumferential surface 44 of the fastening collar 34. In the final fastening position, the first recess 38 and the second recess 42 overlap to form a cavity. Inside the cavity, a locking element 46 is arranged for locking the fastening cap 30 to the lens barrel 22. The locking element 46 of the embodiment shown in Fig. 4 is designed as a spring-loaded plunger. Once the final fastening position is reached and the two recesses overlap, the plunger will be decompressed and pop out from a storing position according to the restoring force of the spring and protrude into the cavity.

Fig. 5 shows a different embodiment of the above described locking mechanism. Reference is made to the features described in the context of Fig. 4. Here, the locking mechanism comprises a locking pin 48, which is designed as a set screw. Once the final fastening position is reached, the recesses overlap and the locking pin 48 can be inserted into the thus formed cavity from outside the lens barrel 22.

In Fig. 6, a motor vehicle 50 comprising at least one automotive camera 10, for example a front camera, side cameras and/or a rear camera, which is implemented according to an exemplary embodiment of the present invention, is shown in a side view. Here, the motor vehicle 50 is formed as a passenger car. The motor vehicle 50 may for example comprise a control unit 52 to control the automotive cameras 10 and/or to receive camera images from them.

In the shown example, the motor vehicle 50 comprises five automotive cameras 10, which are distributed around the motor vehicle 50. One of the automotive cameras 10 is arranged on the rooftop of the vehicle 50, one is arranged in a rear area, one is arranged in a front area and the remaining two automotive cameras 10 are arranged in respective lateral areas. The number and arrangement of the automotive cameras 10 may, however, be different in other examples. Alternatively or in addition, one or more automotive cameras according to the invention may be arranged for capturing an interior space or a passenger compartment of the motor vehicle 50.

The automotive cameras 10 are, in particular, installed to a respective individual motor vehicle component. A motor vehicle component may for example be a bumper or an exterior mirror or a side trim. The motor vehicle component may also be a headliner or an interior trim or a cover of a steering wheel center or an interior mirror. The mentioned motor vehicle components are to be considered only as non-limiting examples.

In an embodiment, an environmental region of the motor vehicle 50 may be captured by an automotive camera 10. In particular, an image sequence or video data, which describes the environmental region, can be provided by the automotive camera 10. The video data may be transmitted from the camera 10 to the control unit 52. By means of the control unit 52, a display device (not shown) of the motor vehicle 50 may be controlled such that the video data of the camera 10 can be displayed to a user of the motor vehicle 50. Thus, the electronic vehicle guidance system may operate as a driver assistance system for assisting a driver of the motor vehicle 50 in driving the motor vehicle 50. Alternatively or in addition, the control unit 52 may process the video data and generate at least one control signal for one or more respective actuators (not shown) of the motor vehicle 50, which may control the motor vehicle 50 automatically or in part automatically based on the control signals.

Fig. 7 schematically shows an exemplary embodiment of the method for assembling an automotive camera 10 according to the invention. The automotive camera 10 comprises a lens assembly 16, wherein the lens assembly 16 comprises a cylindrical lens barrel 22 with at least one lens 26 arranged therein. The lens assembly 16 further comprises a lens opening for allowing light to travel through the lens barrel 22 along an optical axis 20 of the at least one lens 26. In a step S1 a transparent protective cover 28 is arranged at the lens opening for protecting the at least one lens 26 against an environmental influence from outside the automotive camera 10. In a step S2, a fastening cap 30 comprising a central opening 32 and a fastening collar 34 surrounding the central opening 32 is put on the lens barrel 22 at the lens opening. Then, the fastening cap 30 is locked to the lens barrel 22 in a final fastening position (step S3). The fastening cap 30 is locked to the lens barrel 22 by a locking mechanism, wherein the locking mechanism prevents the fastening cap from being moved out of the final fastening position. Overall, the examples illustrate how the invention provides a camera with a front cover window integrated to a lens assembly of the camera.