Camera for a motor vehicle and method for mounting a camera

Abstract

A camera (100) for a motor vehicle, comprising: a camera housing (106) with a lens (101) fixed to the camera housing (106); a circuit board (104) with an image sensor (105) arranged on the circuit board (104), wherein the image sensor (105) faces the lens (101) and is optically aligned therewith; and a carrier element (109) which is fastened to the circuit board (104) on a side of the circuit board (105) facing away from the image sensor (105), and wherein the carrier element (109) has a flat plate (303) which is formed parallel to the circuit board (104).The camera (100) further comprises at least two spacer elements (201) by means of which the carrier element (109) is fastened to the circuit board (104) at a distance from the circuit board (104); and wherein the camera housing (106) has at least one resilient tab (110) pointing away from the lens (101) in the axial direction and extending the camera housing (106); wherein the carrier element (109) has a spherical outer contour (202) for contact with the at least one tab (110).

Description

The present invention relates to a camera for a motor vehicle and to a method for mounting a camera according to the independent claims.Prior ArtThe procedure for mounting known cameras is often as follows: First, an image sensor is fixed to a printed circuit board and a lens holder is adhesively bonded to the printed circuit board. The positioning and fixing of a lens in the lens holder are then usually carried out. In this case, the objective is actively aligned with the image sensor and permanently fixed in the focused position via an adhesive connection.An alternative to this, without adhesive connections, is known from DE 10 2022 211 411. Disclosed here is a camera for a motor vehicle comprising an objective having at least one optical lens; a camera housing, the objective being fixed to the camera housing; a printed circuit board, having an image sensor arranged on the printed circuit board, the image sensor facing the objective and being optically aligned with it. In this case, the camera furthermore comprises a carrier element which is fastened to the printed circuit board on a side of the printed circuit board facing away from the image sensor by means of at least one soldered connection, and wherein the carrier element is formed in such a way that a gap is formed between the camera housing and the carrier element; and at least one gap bridging element which is fastened by means of laser welded connections at contact points to the carrier element and at contact points to the camera housing.It is an object of the present invention to provide a further alternative for a camera without adhesive connections.Disclosure of the InventionThe present invention is based on a camera for a motor vehicle. The camera comprises a camera housing having an objective fixed to the camera housing; a printed circuit board having an image sensor arranged on the printed circuit board, wherein the image sensor faces the objective and is aligned optically with the latter; and a carrier element which is fastened to the printed circuit board on a side of the printed circuit board facing away from the image sensor, and wherein the carrier element has a planar plate which is formed parallel to the printed circuit board.According to the invention, the camera furthermore means at least two spacer elements, by means of which the carrier element is fastened to the circuit board at a distance from the circuit board. Furthermore, the camera housing has at least one resilient tab pointing away from the objective in the axial direction and extending the camera housing. Furthermore, the carrier element has a spherical outer contour for bearing against the at least one tab.The resilient tab of the camera housing can be designed, for example, to extend the camera housing once circumferentially. In this variant, it may be a single resilient tab. Alternatively, the camera housing can have at least two resilient tabs extending the camera housing. The at least two tabs are in particular formed distributed around the camera housing.A lens can be screwed into the camera housing for fixing. Alternatively, the camera can have at least one welded or soldered connection for fixing the objective to the camera housing.The objective can have at least one optical lens. A plurality of optical lenses can be designed as a lens stack. The at least one optical lens can be arranged in an objective housing (lens housing). Here, the lens housing is fixed to the camera housing. Alternatively, the camera housing and the objective housing can be connected to one another as a single-piece component. The at least one lens of the objective is arranged in a region of the camera housing provided for this purpose in this case.The camera can furthermore have a housing cover. The housing cover can be connected to the camera housing on a side of the camera housing facing away from the objective. The camera housing and the housing cover can be connected to one another in such a way that the camera is protected from the ingress of media from the environment of the camera. The camera housing and the housing cover can be connected to one another in a materially bonded or form-fitting manner. The housing cover can be arranged on the at least one resilient tab of the camera housing. The housing cover can cover the at least one resilient tab.The printed circuit board is configured in particular to accommodate the image sensor and the at least two spacer elements. The printed circuit board can accommodate further components, such as a plug of the camera, as well as further electronic components. The fact that the image sensor is aligned with the objective means in particular that the image sensor is placed in the camera housing during a method for mounting the camera in such a way that images which are projected onto the image sensor through the objective have the best possible quality.The camera described here can in particular also have an electrical plug which is designed to electrically connect the printed circuit board. In this case, the planar plate of the carrier element can have an opening through which the plug projects.The flat plate of the carrier element can be formed in a quadrilateral or polygonal manner. This is in particular the case when the camera housing and / or the printed circuit board is / are also designed to be quadrilateral or polygonal. If the flat plate is, for example, rectangular, the camera housing has in particular four resilient straps. These four tabs can each bear against an outer side of the carrier element in the assembled state of the camera. The flat plate can alternatively also be round. This is the case in particular when the camera housing is also round. The resilient tabs of the camera housing can in this case lie distributed around the outer edge of the planar plate in the mounted state of the camera. The spherical outer contour of the carrier element can be understood as a rounded or also a spherical outer contour.During mounting of the camera, the at least two spacer elements can be displaced in contact points with the carrier element during optical alignment along a first axis (image vertical, X axis) and a second axis (image horizontal, Y axis) of the image sensor with respect to the objective. After the optical alignment, the at least two spacer elements can be fixed to the carrier element in the contact points.During mounting of the camera, in particular furthermore the carrier element, the spherical outer contour of which abuts the at least one resilient tab of the camera housing, can be displaced within the camera housing along a third axis (focusing, Z axis) and along a first axis of rotation (rotation of the image sensor about the image vertical, X_rot) and a second axis of rotation (rotation of the image sensor about the image horizontal, Y_rot) for optical alignment. In such an alignment, the resilient tabs can exert force on the carrier element and thus ensure contact with the outer contour of the carrier element.The advantage of the invention is that the at least one resilient tab of the camera housing allows simple alignment of the image sensor with respect to the objective during the mounting of the camera. Thus, the one resilient tab or the plurality of resilient tabs enable the contact of the camera housing with the carrier element. Due to the flexibility of the at least one resilient tab, the carrier element and thus also the printed circuit board with the image sensor can be aligned easily and precisely during assembly.In an advantageous embodiment, it is provided that the convex outer contour abuts at least one contact point of the at least one tab and is fastened to the tab at the at least one contact point by means of laser welded connections.The advantage of this embodiment is that the laser weld connection at the at least one contact point enables a good and long-lived fixing. Adhesive connections in the camera can be avoided. Adhesive compounds have the disadvantage of unfavourable behaviour due to expansion in the event of temperature fluctuations, swelling due to moisture and / or ageing of their properties over time. By avoiding such adhesive connections in the camera presented here, it can be achieved that the optical alignment of the image sensor with respect to the objective can be kept constant. Thus, for example, a change in the distance between the image sensor and the objective and a defocusing associated therewith can be avoided even in the case of temperature fluctuations, humidity or over time. Connections of the objective to the camera housing and also of the printed circuit board or of the carrier element to the camera housing are designed to be very robust in the camera presented here.In a further advantageous embodiment, it is provided that the camera housing has at least three tabs. The spherical outer contour of the carrier element in this case abuts all of the at least three lugs. There is a contact point between each of the at least three brackets and the spherical outer contour of the carrier element. The carrier element can be fastened to the respective tab at each of these contact points by means of laser welds.The advantage of this embodiment is that an even more precise alignment of the image sensor with respect to the objective is made possible during the mounting of the camera.In a further advantageous embodiment, it is provided that the spacer elements are connected to the printed circuit board in a materially bonded or form-fitting manner. A cohesive connection can be, for example, a soldered connection or a welded connection. A form-fit connection can be, for example, a rivet connection. The advantage of this embodiment is that an adhesive connection can be avoided even at this location of the camera.In a further advantageous embodiment, it is provided that the spacer elements are fastened to the carrier element in each case by means of laser welds. The spacer elements are fastened to the carrier element in particular at contact points with respect to the carrier element. The advantage of this embodiment is that adhesive connections can be avoided even at this location of the camera.The invention furthermore relates to a method for mounting a camera. The method includes the following steps: providing a first subassembly comprising a camera housing and an objective fixed to the camera housing, wherein the camera housing has at least one resilient tab pointing away from the objective in the axial direction and extending the camera housing; providing a second subassembly comprising a printed circuit board having an image sensor arranged on the printed circuit board and a carrier element arranged on a side of the printed circuit board facing away from the image sensor, wherein the carrier element is arranged at a distance from the printed circuit board by means of at least two spacer elements, and wherein the carrier element has a planar plate and planar plate is formed parallel to the printed circuit board, and wherein the carrier element has a spherical outer contour; introducing the second subassembly into the camera housing of the first subassembly, wherein the image sensor faces the objective, and wherein the spherical outer contour abuts against the at least one resilient tab; and optically aligning the image sensor with the objective.In particular, in the method for mounting the camera, the at least two spacer elements are displaced in the step of optical alignment along a first axis (image vertical, X axis) and a second axis (image horizontal, Y axis) of the image sensor with respect to the objective in contact points with the carrier element. After the optical alignment, in particular the at least two spacer elements are fixed to the carrier element in the contact points.In particular, in the method for mounting the camera, the carrier element is furthermore displaced within the camera housing in the step of optically aligning along a third axis (focusing, Z axis) and along a first axis of rotation (rotation of the image sensor about the image vertical, X_rot) and a second axis of rotation (rotation of the image sensor about the image horizontal, Y_rot). In this case, the resilient tabs of the camera housing exert a force on the carrier element. The resilient tabs ensure contact with the spherical outer contour of the carrier element.In the step of optically aligning the image sensor with the objective, the image sensor is advantageously actively operated, wherein the obtained image of the test image recorded over the fixed objective is automatically evaluated with regard to a sharpness in different image sections and for different positionings. The final positioning of the image sensor is carried out on the basis of the contrast characteristics determined by the image processing. The final positioning of the image sensor is effected in such a way that a predefined criterion for the image quality over the entire image field is fulfilled. The optical alignment is preferably effected with the aid of a computer-controlled mechanical alignment unit.The advantage of the invention is that the force exerted by the at least one resilient element on the carrier element allows simple alignment of the image sensor with respect to the objective during assembly. Due to the flexibility of the resilient tabs, the carrier element and thus also the printed circuit board with the image sensor can be aligned easily and precisely during assembly.The method described here can be used to produce a camera described above.In an advantageous embodiment, it is provided that the spherical outer contour abuts at least one contact point of the at least one tab and wherein the method comprises the further step of fastening the spherical outer contour to the at least one contact point by means of laser welded connections. The laser welded connections at the contact points enable a good and long-lived fixing. Adhesive connections in the camera can be avoided.In an advantageous embodiment, it is provided that the method comprises the further step of fastening the spacer elements to the carrier element at contact points to the carrier element in each case by means of laser welded connections. The laser welded connections at these contact points enable a good and long-lived fixing. Adhesive connections in the camera can be avoided.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.DRAWINGSExemplary embodiments of the present invention are explained in more detail below with reference to the attached drawings. Identical reference numerals in the figures denote identical or identically acting elements. The following are shown: FIG. 1 shows an exemplary embodiment of a camera in a half-section illustration; FIG. 2 shows the embodiment of the camera in a sectional view; FIG. 3 shows an exemplary embodiment of a positioning of a carrier element on a rear side of a printed circuit board; FIG. 4 shows an exemplary embodiment of the optical alignment and the fastening of the spacer elements to the carrier element; FIG. 5 shows an exemplary embodiment of the optical alignment and the fastening of the resilient tabs at the contact points.FIG. 1 shows an exemplary embodiment of a camera 100 in a half-section illustration. FIG. 2 shows the same exemplary embodiment in a sectional illustration.The camera 100 includes the camera housing 106 with the lens 101 fixed to the camera housing 106. The objective 101 comprises, in this example, the lens stack 103 which is arranged in the objective housing 102. Furthermore, the camera 100 comprises the printed circuit board 104. The image sensor 105 is arranged on the printed circuit board 104. The image sensor 105 is facing the objective 101 and is optically aligned with it. The camera 100 also comprises a carrier element 109 which is fastened to the circuit board 104 on the side of the circuit board 104 facing away from the image sensor 105. On the side of the printed circuit board 104 facing away from the image sensor 105, the plug 108 is also arranged in the example shown here. The plug 108 projects through a recess of the carrier element 109. The camera 100 shown here also has the housing cover 107. This also comprises a recess through which the plug 108 protrudes into an exterior of the camera 100.The camera housing 106 has at least one resilient tab 110 pointing away from the objective 101 in the axial direction and extending the camera housing 106. In the present case, both the camera housing 106 and the carrier element 109 and the printed circuit board 104 are each formed square from their base area. Thus, in this example, in particular a resilient tab 110 can each abut an outer edge of the carrier element 109. The housing cover 107 is designed such that it is arranged so as to lie against the at least one resilient tab 110 of the camera housing 106. The at least one resilient tab 110 is thus covered by the housing cover 107 toward an exterior of the camera 100.It can also be seen in FIG. 2 that the camera 100 furthermore has at least two spacer elements 201. The carrier element 109 is fastened at a distance from the printed circuit board 104 by means of the spacer elements 201. The spacer elements 201 can be connected to the printed circuit board 104 in a materially bonded or form-fitting manner. The spacer elements 201 can furthermore be fastened to the carrier element 109 in each case by means of laser welds.It can also be seen in FIG. 2 that the carrier element 109 has a spherical outer contour 202. With this spherical outer contour 202, the carrier element 109 abuts the at least one tab 110. The at least one resilient tab 110 presses at contact points 203 against the spherical outer contour of the carrier element 109. The spherical outer contour of one two can be fastened to the at least one tab 110 at the contact points 203 by means of a laser weld connection.FIG. 3 shows an exemplary embodiment of a positioning of a carrier element 109 on a rear side of a printed circuit board 104. In other words, only parts of the camera 100 illustrated in FIGS. 1 and 2 can be seen here. The exact positioning of the carrier element 109 or, in other words, the optical alignment is described further below in the method illustrated in FIGS. 4 and 5 for mounting a camera described above.The printed circuit board 104 can be seen here as part of the camera 100. The printed circuit board 104 shown here also has an image sensor, which is not visible in this illustration, however. The carrier element 109 arranged on the side of the printed circuit board 104 facing away from the image sensor can be seen. The support member 109 has the flat plate 303 formed parallel to the circuit board 104. The planar plate 303 of the present example is formed square from its base. It can also be seen that the carrier element 109 has a cutout 301 in the middle, through which a plug 108 protrudes from the printed circuit board 104.The camera housing 106 and the lens fixed to the camera housing 106 with a lens housing 102 can also be seen. The camera housing 106 is also rectangular in shape from its base. The camera housing 106 has four resilient tabs 110- 1 to 110- 4 pointing away from the lens in the axial direction and extending the camera housing 106. The resilient tabs 110- 1 to 110- 4 are distributed around the camera housing 106. On each side of the square camera body 106, a resilient tab 110- 1, 110- 2, 110- 3, and 110- 4 faces away from the lens.Here too, the carrier element 109 has a spherical outer contour against which the four tabs 110- 1 to 110- 4 bear. The subassembly further comprises the four spacer elements 201- 1 to 201- 4.In a method of assembling a camera 100 described above, one step is optically aligning the image sensor 105 with the lens 101. This optical alignment can comprise two substeps which are described below in each of FIGS. 4 and 5.FIG. 4 shows an exemplary embodiment of the optical alignment and the fastening of the spacer elements 201 to the carrier element 109. In particular, FIG. 4 shows a substep of the optical alignment. FIG. 4 shows a detail of the method for mounting a camera described above. In this case, a second subassembly, comprising a printed circuit board 104 having an image sensor 105 arranged on the printed circuit board 104 and a carrier element 109 arranged on a side of the printed circuit board 104 facing away from the image sensor 105, has already been introduced into a first subassembly, comprising a camera housing 106 and an objective 101 fixed to the camera housing, wherein the camera housing 106 has at least one resilient tab 110 pointing away from the objective 101 in the axial direction and extending the camera housing 106. The carrier element 109 is furthermore arranged at a distance from the printed circuit board 104 by means of at least two-spacer elements 201. The carrier element 109 also has a planar plate, wherein the planar plate is formed parallel to the printed circuit board 104. Furthermore, the carrier element 109 has a spherical outer contour 202.The at least one resilient tab 110 of the camera housing 106 here exerts a force on the spherical outer contour of the carrier element 109 at the points of contact with the carrier element 109. In other words, the at least one resilient tab 110 presses against the spherical outer contour of the carrier element 109. The at least one resilient tab 110 can press with sufficient pressure against the spherical outer contour 202 of the carrier element 109. As a result, the carrier element 109 can be held in a so-called preposition in an advantageous manner, but a displacement of the carrier element 109 can still be made possible during the optical alignment.The spacer elements 201 and thus the circuit board 104 with the image sensor 105 fastened thereto are still movable at this stage of the method. The spacer elements 201 are not yet fastened to the carrier element 109 here. Rather, the spacer elements 201 can each be displaced in a recess 401 of the carrier element 109. In order to align the image sensor 105 with the objective 101, the spacer elements 201 and thus the circuit board 104 fastened thereto with the image sensor 105 can be displaced along a first axis (X axis) and along a second axis (Y axis) of the image sensor. This is symbolized by the double arrow marked X, Y. The alignment along these two axes can subsequently be fixed by fastening the spacer elements 201 to the carrier element 109. For this purpose, the spacer elements 201 can be fastened to the carrier element 109 in each case by means of a laser weld connection 402.FIG. 5 shows an embodiment of the optical alignment and the fastening of the resilient tabs 110 of the camera housing 106 at the contact points. In particular, FIG. 5 shows a substep of the optical alignment. The substep shown here can be carried out, for example, subsequently to the substep from FIG. 4. Due to the flexibility of the resilient tabs 110, the carrier element 109 and thus also the printed circuit board 104 can be aligned with the image sensor 105 during the method for mounting a camera 100 described above. The carrier element 109 is initially still movable at this stage of the method. Thus, in this substep, the carrier element 109 can be displaced along a third axis (Z axis) and along a first axis of rotation (X_rot) and a second axis of rotation (Y_rot) within the camera housing 106. This is symbolized by the double arrow marked Z, X_rot and Y_rot. The alignment along these axes can subsequently be fixed by fastening the resilient tabs 110 at the contact points. For this purpose, the resilient tabs 110 can be fastened to the contact points in each case by means of a laser welded connection 501.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2022 211 411

[0003]

Claims

Camera (100) for a motor vehicle comprising: • a camera housing (106) having an objective (101) fixed to the camera housing (106); • a printed circuit board (104) having an image sensor (105) arranged on the printed circuit board (104), wherein the image sensor (105) faces the objective (101) and is aligned optically with the latter; and • a carrier element (109) which is fastened to the printed circuit board (104) on a side of the printed circuit board (105) facing away from the image sensor (105), and wherein the carrier element (109) has a planar plate (303) which is formed parallel to the printed circuit board (104); characterized in that • the camera (100) furthermore has at least two spacer elements (201), by means of which the carrier element (109) is fastened to the printed circuit board (104) at a distance from the printed circuit board (104); and wherein • the camera housing (106) has at least one resilient tab (110) pointing away from the lens (101) in the axial direction and extending the camera housing (106); • wherein the carrier element (109) has a spherical outer contour (202) for bearing against the at least one tab (110).Camera (100) according to claim 1, wherein the spherical outer contour (202) abuts at least one contact point (203) of the at least one tab (110) and is fastened to the tab (110) at the at least one contact point (203) by means of a laser weld joint (503).The camera (100) of any preceding claim, wherein the camera housing (106) includes at least three tabs (110).Camera (100) according to one of the preceding claims, wherein the spacer elements (201) are connected to the printed circuit board (104) in a materially bonded or form-fitting manner.Camera (100) according to one of the preceding claims, wherein the spacer elements (201) are fastened to the carrier element (109) in each case by means of laser welds (402).Method for mounting a camera, comprising the steps of: • providing a first subassembly comprising a camera housing and an objective fixed to the camera housing, wherein the camera housing has at least one resilient tab pointing away from the objective in the axial direction and extending the camera housing; • providing a second subassembly comprising a printed circuit board having an image sensor arranged on the printed circuit board and a carrier element arranged on a side of the printed circuit board facing away from the image sensor, wherein the carrier element is arranged spaced apart from the printed circuit board by means of at least two spacer elements, and wherein the carrier element has a planar plate and the planar plate is formed parallel to the printed circuit board, and wherein the carrier element has a spherical outer contour; • introducing the second subassembly into the camera housing of the first subassembly, wherein the image sensor faces the objective, and wherein the spherical outer contour bears against the at least one resilient tab; • Optical alignment of the image sensor with the objective.The method of claim 6, wherein the crowned outer contour abuts at least one contact location of the at least one tab, and wherein the method comprises the further step of securing the crowned outer contour to the at least one contact location by means of a laser weld joint.The method of claim 6, comprising the further step of securing the spacer elements to the support member at points of contact with the support member by laser welds, respectively.

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