Method for optically aligning a lens barrel of a camera

Abstract

The invention relates to a method for optically aligning a lens barrel (10) of a camera (14), wherein optical elements (18) are arranged in the lens barrel (10), and the method comprises at least the step of forming at least one blind weld (26) on a circumference of the lens barrel (10), via which blind weld the optical elements (18) are optically aligned with respect to one another and / or with respect to an image sensor (22) of the camera (14).

Description

[0001] Description

[0002] Title:

[0003] Method for optically aligning a lens barrel of a camera

[0004] The present invention relates to a method for optically aligning a lens barrel of a camera. Furthermore, the invention relates to a camera comprising a lens barrel optically aligned according to this method.

[0005] State of the art

[0006] Camera systems are used in many areas. For example, such camera systems are used in motor vehicles as optical camera systems for capturing information. These camera systems record the vehicle's surroundings, for example, and provide information to other vehicle systems.

[0007] When mounting (automotive) cameras, the alignment of the lens to the housing is performed using active alignment. This involves aligning the lens to a reference point, thus bringing the projected image onto the image sensor into focus. A UV-curing adhesive is typically used to fix and permanently hold this position. This adhesive is applied to the adhesive surface of the lens mount prior to active alignment. After alignment, it is flashed with UV light to initially partially cure the lens and temporarily hold the adjusted position. The adhesive is then oven-cured with the camera module to achieve long-term strength.

[0008] DE 10 2021 206 458 A1 describes a method for manufacturing a camera module. The method comprises the steps of optically aligning a lens to an image sensor of the camera module. Before or after the optical alignment, at least three solder elements are inserted into a gap between the lens and a lens holder holding the lens. These solder elements are then melted using a laser beam, thus fixing the lens in an aligned position.

[0009] US 2022 / 0334339 A1 describes a camera module with a lens assembly. The lens assembly comprises a plurality of lens tubes in which lenses are arranged, with the plurality of lens tubes arranged one above the other. The lens tubes are connected to one another in an aligned position using adhesive or a laser weld.

[0010] The object underlying the invention is to provide a method for optically aligning a lens barrel of the camera, with which an optical alignment of the optical elements in the lens barrel to one another or to an image sensor is possible in a simple manner even after the optical elements have been attached.

[0011] The object is achieved by a method for optically aligning a lens barrel of a camera having the subject matter of patent claim 1. Furthermore, the object is achieved by a camera having the features of claim 7. Preferred embodiments can be found in the dependent claims.

[0012] Disclosure of the invention

[0013] The invention specifies a method for optically aligning a lens barrel of a camera, wherein optical elements are arranged in the lens barrel, and the method comprises at least the step of forming at least one blind weld on a circumference of the lens barrel, via which blind weld the optical elements are optically aligned to one another and / or to an image sensor of the camera. Optical elements are understood to be elements which change a beam path of the incident light. The optical elements are preferably lenses. A blind weld is understood to be a weld which takes place without joining or connecting to a third object. As a result of the blind weld, the material of the lens barrel is partially melted, resulting in shrinkage or shortening in this area. By providing such blind welds, it is thus possible to optically align the optical elements to one another and / or to an image sensor of the camera.to align with the image sensor.

[0014] Such optical alignment is also possible after the optical elements have been mounted in the lens barrel. The specifications for the positioning of the optical elements in the lens barrel may therefore be less accurate. This simplifies the production of a camera with such a lens barrel and makes it more cost-effective. Subsequent optical alignment also makes it possible to increase the accuracy of the optical alignment, thus improving the image obtained by the camera. It is also possible to correct any aberrations that may occur during camera operation.

[0015] In a preferred embodiment of the invention, at least one optical element is fixed in the lens barrel via the blind weld. By attaching the optical element via the blind weld, other fastening methods can be dispensed with. In contrast to other fastening methods, fastening via a blind weld is easier to implement. In particular, no additional fastening materials are required to secure the optical element in the lens barrel. Fastening via a blind weld is therefore cost-effective.

[0016] In a further preferred embodiment of the invention, the blind weld is formed as a circumferential weld seam in order to reduce the axial length of the lens barrel in this area. The blind weld runs continuously over the entire circumference of the lens barrel. As a result, the length of the lens barrel in the area in which the blind weld is formed can be reduced consistently over the entire circumference. By adjusting the height of the blind weld, the amount of length change can also be adjusted. Thus, even after the lenses have been fixed, it is possible to change the distance between the lenses or to the image sensor. Image quality can thereby be further improved.

[0017] Preferably, a plurality of blind welds aligned in the axial direction of the lens barrel and spaced from one another in the circumferential direction are formed on a circumference of the lens barrel in order to reduce an axial length of the lens barrel in this area. The blind welds all have a predetermined axial length. The axial length is determined by the extent to which a distance between optical elements is to be reduced. The blind welds are arranged at the same height over the entire circumference. In contrast to a continuous weld seam, this type of blind weld design has the advantage that a greater reduction in the axial length can be achieved in this area.

[0018] In an advantageous development, the blind weld is formed in a region of a circumference of the lens barrel in order to change an angle of at least one optical element to the image sensor and / or another optical element. The blind weld is therefore not provided over the entire circumference. Rather, the blind weld is arranged at specific points or over a specific circumferential area. This merely reduces an axial length in this area. Accordingly, tilting occurs so that an angle can be changed. By appropriately positioning the blind weld, it is therefore also possible to adjust where the optical element is to be tilted. This makes it easy to set an angle between the optical elements to one another or to the image sensor even after the optical elements have been attached.

[0019] Advantageously, the blind weld is formed using a laser. By using a laser to form the blind weld, it is possible to create such a weld even very small. Accordingly, by adjusting the size of the blind weld, it is possible to adjust the amount of length change or the amount of angle change with high precision. This makes it possible to align the optical elements with each other with high precision, thus improving image quality. Furthermore, welding using a laser enables automated production, making such optical alignment economically feasible.

[0020] The object underlying the invention is additionally achieved by a camera comprising a lens barrel that has been optically aligned according to the method according to the invention. Optical elements are arranged in the lens barrel, and at least one blind weld is provided on a circumference of the lens barrel. Such a camera has the properties and advantages described above.

[0021] In a further advantageous embodiment, the at least one blind weld is arranged between two optical elements of the lens barrel. Unlike other welded joints, such a blind weld does not serve to form a holding function. Such a blind weld thus serves exclusively to reduce the axial length between optical elements. Such blind welds thus make it possible to economically optically align a camera's lens barrel.

[0022] According to a practical embodiment, an optical element is secured in the lens barrel via the at least one blind weld. By securing the optical element via the blind weld, fixing the optical element in the lens barrel is simplified.

[0023] According to another advantageous embodiment, the blind weld is a laser weld. This type of weld has the properties and advantages described above.

[0024] Embodiments of the invention are illustrated in the drawing and explained in more detail in the following description. Figure 1 shows a sectional view of a lens barrel of a camera according to a first embodiment of the invention.

[0025] Figure 2 shows a sectional view of a lens barrel of a camera according to a second embodiment of the invention,

[0026] Figure 3 shows a sectional view of a lens barrel of a camera according to a third embodiment of the invention,

[0027] Figure 4 shows a sectional view of a lens barrel of a camera according to a fourth embodiment of the invention, and

[0028] Figure 5 external view of a lens barrel of a camera according to a fifth embodiment of the invention, and

[0029] Figure 1 shows a sectional view of a lens barrel 10 of a camera 14 according to a first exemplary embodiment of the invention. In the exemplary embodiment shown, the lens barrel 10 is designed as a hollow cylinder. Several optical elements 18 are arranged in the lens barrel 10 along an axial length of the lens barrel 10. In the exemplary embodiment shown, the optical elements 18 are designed as lenses. Additionally, an image sensor 22 of the camera 14 is shown, to which the lens barrel 10 is to be optically aligned.

[0030] In the exemplary embodiment shown, a blind weld 26 is formed on a circumference of the lens tube 10. The blind weld 26 is positioned between two lenses 18 and extends over the entire circumference of the lens tube 10. The blind weld 26 can be formed using a laser. The blind weld 26 reduces an axial length Z of the lens tube by a length amount AZ. Accordingly, a distance Z between two lenses 18 can be reduced, so that the lenses 18 can be optically aligned with one another or with the image sensor 22 along a longitudinal axis 30. Figure 2 shows a sectional view of a lens tube 10 of the camera 14 according to a second exemplary embodiment of the invention. In contrast to the exemplary embodiment in Figure 1, the blind weld 26 does not extend over the entire circumference of the lens tube 10. Rather, the blind weld 26 is formed at specific points or in certain regions.This blind weld 26 is also provided between two lenses 18. Accordingly, only the distance between the lenses 18 on the side where the blind weld 26 is formed can be reduced. This allows the alignment of the lenses 18 relative to one another to be adjusted by an angular amount Ao.

[0031] Figure 3 shows a sectional view of a lens barrel 10 of the camera 14 according to a third exemplary embodiment of the invention. This exemplary embodiment differs from the previous exemplary embodiments in that two blind welds 26 are provided on the lens barrel 10. The two blind welds 26 are provided above and below one of the lenses 18 in such a way that the latter is fastened within the lens barrel 10. Other fastening methods for this lens 18 can therefore be dispensed with. The blind weld 26 above the lens 18 is designed in such a way that an axial length Z between lenses is additionally reduced. The blind welds 26 shown therefore not only allow the lens 18 to be fastened within the lens barrel 10, but also allow the lenses 18 to be optically aligned with one another.

[0032] Figure 4 shows a further embodiment of a lens barrel 10 of the camera 14. The embodiment shown in this figure differs from the embodiment in Figure 3 in that a larger blind weld 26 is formed only at a specific point on one side of the lens barrel 10. Accordingly, the lenses 18 can be adjusted by an angular amount Ao. In this embodiment too, a lens 18 is fastened in the lens barrel 10 via blind welds 26 arranged above and below the lens 18. Additionally, this figure shows that the lenses 18 can also be fastened by a blind weld 26 directly in the area of ​​the lens 18 within the lens barrel 10. Figure 5 shows an external view of a lens barrel 10 of the camera 14 according to a fifth embodiment of the invention.In contrast to the blind weld 26 in Figure 1, in this embodiment, no continuous blind weld 26 is formed along the circumference of the lens barrel 10. Rather, a plurality of blind welds 26 are formed in the axial direction of the lens barrel 10.

[0033] Blind welds 26 are provided extending along the lens barrel 10, which are spaced apart from one another and formed circumferentially on the lens barrel 10. By forming the blind welds 26 in this way, a distance Z between the lenses can be reduced by a length AZ compared to Figure 1.

Claims

Claims 1. A method for optically aligning a lens barrel (10) of a camera (14), wherein optical elements (18) are arranged in the lens barrel (10), and the method comprises at least the step of forming at least one blind weld (26) on a circumference of the lens barrel (10), via which the optical elements (18) are optically aligned with one another and / or with an image sensor (22) of the camera (14).

2. Method according to claim 1, characterized in that at least one optical element (18) is fixed in the lens barrel (10) via the blind weld (26).

3. Method according to claim 1 or 2, characterized in that the blind weld (26) is formed as a circumferential weld seam in order to reduce an axial length (Z) of the lens barrel (10) in this region.

4. Method according to one of the preceding claims, characterized in that a plurality of blind welds (26) aligned in the axial direction of the lens barrel (10) and spaced from one another in the circumferential direction are formed on a circumference of the lens barrel (10) in order to reduce an axial length (Z) of the lens barrel (10) in this region.

5. Method according to one of the preceding claims, characterized in that the blind weld (26) is formed in a region of a circumference of the lens barrel (10) in order to change an angle (a) of at least one optical element (18) to the image sensor (22) and / or a further optical element (18).

6. Method according to one of the preceding claims, characterized in that the blind weld (26) is formed by means of a laser.

7. A camera (14) comprising a lens barrel (10) aligned according to any one of the preceding claims, wherein optical elements (18) are arranged in the lens barrel (10), and at least one blind weld (26) is provided on a circumference of the lens barrel (10).

8. The camera (14) according to claim 7, characterized in that the at least one blind weld (26) is arranged between two optical elements (18) of the lens barrel (10).

9. The camera (14) according to claim 7 or 8, characterized in that an optical element (18) is fastened in the lens barrel (10) via the at least one blind weld (26).

10. Camera according to one of claims 7 to 9, characterized in that the blind weld (26) is a laser weld.

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