Method for assembling an optical device and optical device assembled according to the method

Abstract

A method for assembling an optical device and an optical device assembled according to the method are provided. A method for assembling an optical device (1) includes: providing a circuit board (3) having an imager (8) mounted thereon, wherein the imager has an effective area (81). A housing (2, 4) is provided having a support (7) and an opening (6), the support for supporting the circuit board (3) and the opening for optical paths to form an image (9) at a known image position relative to the opening (3). The circuit board (3) is positioned on the support and its position is adjusted using one or more manipulators (10) to align the effective area with the image position (9). The circuit board can then be secured in the aligned position.

Description

Technical Field

[0001] This disclosure relates to a method for assembling optical devices. It also relates to optical devices assembled using this method. Specifically, the invention relates to a method for assembling automotive cameras and the manufacture of camera assemblies for automotive applications. Background Technology

[0002] Cameras and other optical devices are critical sensors in automotive applications, especially with the increasing prevalence of autonomous driving and safety assistance systems. As these systems become more advanced, the use of higher resolution cameras is driven. However, with the increase in the resolution of digital cameras, they become more sensitive to optical misalignment, which is caused by, for example, tolerances during the manufacturing process and strain and deformation that occurs when the camera's imager is fixed in place.

[0003] In this regard, during the conventional camera assembly process, the imager, soldered onto a printed circuit board (PCB), is typically mechanically secured to a lens support or housing by means of the PCB, for example, using screws. The lens is then actively aligned with the imager assembly to align its focal plane with the sensitivity plane of the imager sensor. This allows for a converging image output. When in its aligned position, the lens is secured by curing adhesive at the mounting interface between the lens and the lens holder.

[0004] The assembly process described above is relatively expensive due to the number of steps that must be performed.

[0005] Furthermore, positioning inaccuracies can still occur. For example, while the active lens alignment step can be used to correct for tilt of the imager relative to the lens element, it does not address potential rotation of the imager relative to the lens holder or housing. This rotational inaccuracy can arise, for example, due to how the imager is mounted on the PCB itself and / or how the PCB is positioned when secured to the lens holder. For instance, one or more overtightened screws can move the PCB relative to the lens holder or housing, thereby moving the imager. This results in a slight rotation of the image frame when the subassembly is subsequently installed into the vehicle. This becomes an increasingly serious problem as modern vehicle sensor systems require camera devices to provide consistent and accurate image frames. In fact, many vehicle manufacturers (OEMs) now require rotation variations in image frames of no more than 3%, posing a significant challenge to using conventional methods and structures.

[0006] In view of the above, there is a need for improved optical device manufacturing methods and structures. Summary of the Invention

[0007] According to a first aspect, a method for assembling an optical device is provided, the method comprising the steps of: providing a circuit board on which an imager is mounted, wherein the imager has an effective area; providing a housing having a support and an opening, the support for supporting the circuit board, the opening for an optical path to form an image at a known image position relative to the opening; setting the circuit board on the support; adjusting the position of the circuit board on the support using one or more manipulators to align the effective area with the image position; and securing the circuit board in the aligned position.

[0008] This allows for higher accuracy in optical devices such as cameras, where the image converged onto the imager can be more accurately aligned with the effective area of ​​the imager. In other words, in the resulting assembly, the sensitive portion of the imager's upper surface used to form image frame data can be positioned to more accurately match the position of the image projected by the lens. Thus, the image converged by the lens can coincide with or substantially coincide with the effective area of ​​the imager. This accuracy is also achieved through physical adjustments using one or more manipulators to precisely move the circuit board to its position within each component, ensuring manufacturing consistency. Therefore, it allows for the production of high-precision optical devices that meet OEM supply requirements.

[0009] In one embodiment, the step of adjusting the position of the circuit board includes rotating the circuit board on the support to align the effective area with the image position. This allows the orientation of the imager's effective area to be accurately aligned to match the orientation of the projected image.

[0010] In one embodiment, the step of providing the housing includes providing a lens retainer portion of the housing and a backing portion of the housing for connection to the lens retainer portion. Thus, the housing can be configured as a two-part assembly to allow a circuit board to be housed within it.

[0011] In one embodiment, the method further includes the steps of: assembling the lens retainer portion and the backing portion together after the circuit board is placed on the support, wherein the support is formed in the backing portion, and adjusting the position of the circuit board includes inserting one or more manipulators through the opening. This allows access to the circuit board using the opening in the housing assembly, thereby allowing the circuit board to be moved for precise positioning. This can also be performed while the component is assembled but before fixing. Therefore, subsequent assembly steps that might otherwise compromise accuracy can be avoided.

[0012] In several embodiments, the method further includes the step of assembling the lens holder portion and the backing portion together after the position of the circuit board has been adjusted, wherein the support member is disposed on the lens holder portion, and the step of adjusting the position of the circuit board includes engaging one or more manipulators via an exposed rear region of the lens holder portion. This allows the circuit board to be accessed using an opening in the rear of the housing assembly, thereby allowing the circuit board to be easily moved to a precise position while it is within the lens holder.

[0013] In one embodiment, the step of securing the circuit board in the alignment position includes connecting the lens holder portion to the backing portion and securing the connection between the lens holder portion and the backing portion. Thus, the lens holder portion and the backing portion can be assembled together by aligning their mating portions, and then the connection can be secured to hold these portions together.

[0014] In one embodiment, the housing further includes one or more clamping structures, wherein the step of securing the circuit board includes: the one or more clamping structures clamping the circuit board against the support member. Thus, when the circuit board is in an aligned position against the support member, the clamping action of the clamping structures can be used to secure the circuit board in place without the need for screws, fasteners, or adhesives. The clamping structures can be, for example, structures corresponding to the support member. Such structures can be disposed on opposing surfaces within the housing.

[0015] In one embodiment, the step of providing the housing includes providing a mating surface for engaging the circuit board to the support member, wherein the mating surface includes at least one of a heat sink for conducting heat away from the circuit board and a ground plane for grounding the circuit board. Thus, the support member can be used for thermal stabilization or electrical grounding of the circuit board. This can improve the operation and reliability of the optical device. In another embodiment, the heat sink and / or ground plane may be provided on one or more corresponding clamping structures.

[0016] In one embodiment, the method further includes the steps of projecting a projected image onto the known image location using a projector, and adjusting the position of the circuit board including aligning the effective area with the projected image. This allows for precise alignment by simulating the optical path produced by the lens when using an optical device. For example, the projected image may include position markers, and feedback from the imager itself can be used to identify when the position markers are correctly positioned. A precisely calibrated locator can be provided to the device for positioning the housing relative to the projector.

[0017] According to the second aspect, an optical device manufactured according to the above method is provided.

[0018] According to a third aspect, a manufacturing apparatus for use during the above-described method is provided, the manufacturing apparatus comprising one or more manipulators and a controller, the controller being configured to control the one or more manipulators to align the effective area with the image position. Thus, an apparatus for assembling and accurately configuring optical devices can be provided.

[0019] According to a fourth aspect, an optical device is provided, the optical device comprising: a circuit board on which an imager is mounted; and a housing including a lens holding portion having an opening for an optical path and a backing portion connected to the lens holding portion, wherein the circuit board is fixed in place by a clamping action between the lens holding portion and the backing portion.

[0020] This provides an optical device in which a circuit board (e.g., a printed circuit board (PCB)) is clamped into place by the housing assembly itself. This eliminates the need for separate fasteners (e.g., screws, other fasteners, or adhesives) to independently secure the circuit board to a portion of the housing. Therefore, the surface area of ​​the circuit board is not unnecessarily occupied by mounting locations for additional fasteners. Furthermore, manufacturing efficiency is improved by eliminating the need for a separate fastening step for securing the circuit board.

[0021] In one embodiment, one of the lens retainer portion and the backing portion includes a support member for supporting the circuit board, and the other of the lens retainer portion and the backing portion includes one or more clamping structures that clamp the circuit board against the support member. Thus, the combined structure within the housing component provides a securing device for the circuit board, thereby avoiding the need for additional mounting methods such as screws, thermal riveting, or gluing.

[0022] In one embodiment, at least one of the lens holder portion and the backing portion includes at least one of a heat sink for conducting heat away from the circuit board and a ground plane for grounding the circuit board. This allows the assembly to provide improved thermal performance and / or electromagnetic compatibility.

[0023] According to a fifth aspect, a method for assembling an optical device is provided, the method comprising the steps of: providing a circuit board on which an imager is mounted; providing a lens holding portion having an opening for an optical path and a backing portion for connecting to the lens holding portion; and connecting the backing portion and the lens holding portion together, and securing the connection by a clamping action between the lens holding portion and the backing portion to fix the circuit board in place. Thus, a method for assembling the aforementioned optical device is provided. Attached Figure Description

[0024] An illustrative embodiment will now be described with reference to the accompanying drawings, in which:

[0025] Figure 1 An exploded view of a camera according to an illustrative embodiment is shown;

[0026] Figure 2 It shows Figure 1 The image shows a partial cross-sectional view of the assembled camera.

[0027] Figure 3 It shows Figure 1 The camera shown is in top view during the alignment step;

[0028] Figure 4 It shows Figure 3 The isometric view of the camera shown during the alignment step; and

[0029] Figure 5 An isometric view of a camera according to another embodiment is shown during the alignment step. Detailed Implementation

[0030] Figure 1 An exploded view of a camera 1 according to an illustrative embodiment is shown. The camera 1 includes a front housing portion 2, a rear housing portion 4, and a PCB 3, with an imager (not visible in this figure) soldered onto the PCB 3.

[0031] The front housing portion 2 includes an opening 6, which forms a lens holder for supporting the lens at the front of the assembly. The main body of the front housing portion 2 defines a cavity containing three clamping structures 5 against which the PCB 3 can be engaged. Each clamping structure 5 includes a metal pad forming a rearward engagement surface for engagement with the PCB 3. A flange 21 is provided around the wall of the main body for positioning the front housing portion 2 relative to the rear housing portion 4 when assembled. In this embodiment, the housing is formed as a polymer molded part.

[0032] The rear housing portion 4 forms a cover or backing portion for the front of the housing. A cable access port P is provided for connecting power and data cables to PCB 3. Figure 2 As shown, a clamping structure 7 is also provided inside the rear housing portion 4, corresponding to the clamping structure 5 provided on the front housing portion 2. Thus, the clamping structure 7 is positioned opposite the clamping structure 5 and serves to clamp the PCB 3 into place when the components are assembled. Furthermore, as... Figure 2 As shown, after assembly, flange 21 is located within the wall of the rear housing portion 4, and these opposing surfaces provide mating areas for aligning the housing portions. At the front of the assembly, an opening 6 is provided above the PCB 3 (in... Figure 2 (As shown at the top).

[0033] In this embodiment, during the assembly of the camera 1, the PCB 3 can be placed on the clamping structure 7 provided on the rear housing portion 4. In this way, the clamping structure supports the rear surface of the PCB 3. Then, the front housing portion 2 is assembled to the rear housing portion 4, thereby engaging the clamping structure 5 with the front surface of the PCB 3. It should be understood that in other embodiments, the PCB 3 can alternatively be first placed on the clamping structure 5 provided on the front housing portion 2, and then the rear housing portion 4 is assembled thereon. In this case, the clamping structure 5 acts as a support. After initial assembly, the front housing portion 2 and the rear housing portion 4 are loosely connected, and the fixing of these two portions is carried out in a later process. Thus, at this stage, the PCB 3 is loosely held in place between the clamping structure 5 and the clamping structure 7.

[0034] Figure 3 and Figure 4 They are shown respectively Figure 1 The images show top and isometric views of the camera during the alignment step of the assembly process. With the components joined together, the assembly can be positioned in a locator within a manufacturing apparatus (not shown). The locator positions the assembly below a projector 11, which projects an image through opening 6 to simulate the converging image produced by the lens after assembly. The manufacturing apparatus also includes two manipulators 10 inserted through opening 6 and used to position the PCB 3 under the control of a controller (not shown).

[0035] In this connection, such as in Figure 3 As best shown in the top view, the imager 8 is mounted to the PCB 3 and includes an effective area 81. The effective area 81 corresponds to the portion of the imager 8 used to detect incident light rays, which are then used to form the resulting image. As shown, during assembly, the projector 11 projects an analog image 9 onto the interior of the front housing portion 2 and the rear housing portion 4. The position of the PCB 3 is then adjusted using a manipulator 10 to align the effective area 81 of the imager 8 with the position of the projected image 9. That is, the controller controls the manipulator 10 to shift and rotate the PCB to its placement position within the housing such that the effective area 81 matches the projected image 9. Feedback for this control can be provided, for example, by feedback detected from the imager 8 itself or by an optical device facing the front of the assembly to monitor alignment with the projected image. The projected image can be, for example, a projection laser locator. In other embodiments, it will also be understood that the projector 11 can be replaced by a camera used to visualize the position of the effective area 81, wherein the camera is calibrated to be positionally accurate.

[0036] When the manipulator 10 positions the PCB 3, the front housing portion 2 and the rear housing portion 4 can be pressed together to clamp the PCB 3 between the clamping structures 5 and 7. The housing portions can then be secured to hold the circuit board 3 in the aligned position. This securing can be achieved using adhesives or fasteners such as screws. For example, a heat- or UV-curable adhesive can be applied between the mating areas of the housing components to secure and stabilize their connection.

[0037] Figure 5 An isometric view of the camera 1 according to another embodiment during the alignment step is shown. This embodiment is essentially the same as the one described above, except that the manipulator 10 approaches the PCB 3 via the rear of the housing. That is, during the assembly of the camera 1, the PCB 3 abuts against the clamping structure 5 disposed on the front housing portion 2. Thus, the clamping structure 5 supports the front surface of the PCB 3. With the rear housing portion 4 not connected, the manipulator 10 can then engage with the rear surface of the PCB 3. The manipulator 10 can thus move the position of the PCB 3 to align the effective area 81 of the imager 8 with the location where the image will be converged by the lens. In place, the rear housing portion 4 can be connected to the front housing portion 2 and secured to hold the PCB 3 in place.

[0038] Therefore, using the above structure, an improved optical device and assembly method can be provided for the production of cameras with more accurate and consistent imager positioning. Furthermore, using the housing component to clamp the PCB in place means that no additional fixing is required.

[0039] It should be understood that the above embodiments are merely illustrative examples for purposes of explanation. In practice, the embodiments can be applied to many different configurations, and detailed embodiments are readily implemented by those skilled in the art.

Claims

1. A method of assembling an optical device, the method comprising the steps of: providing a circuit board having an imager mounted thereon, wherein the imager has an active area; providing a housing having a support for supporting the circuit board and an opening for an optical path to form an image at a known image location relative to the opening; positioning the circuit board on the support; adjusting the position of the circuit board on the support using one or more manipulators inserted through the opening to align the active area with the image location; and fixing the circuit board in the aligned position.

2. The method of claim 1, wherein, The step of adjusting the position of the circuit board comprises rotating the circuit board on the support to align the active area with the image location.

3. The method of claim 1 or 2, wherein, The step of providing a housing comprises providing a lens holder portion of the housing and a backing portion of the housing for connecting to the lens holder portion.

4. The method according to claim 3, further comprising the step of assembling the lens holder portion and the backing portion together after the circuit board is disposed on the support, and wherein, The support is formed in the backing portion.

5. The method of claim 3, wherein, The step of fixing the circuit board in the aligned position comprises connecting the lens holder portion to the backing portion and securing the connection between the lens holder portion and the backing portion.

6. The method of claim 5, wherein, The housing further comprises one or more clamping structures, wherein the step of fixing the circuit board comprises the one or more clamping structures clamping the circuit board against the support.

7. The method of claim 1, wherein, The step of providing a housing comprises providing the support with an engagement face for engaging the circuit board, wherein the engagement face comprises at least one of a heat sink face for conducting heat away from the circuit board and a ground face for grounding the circuit board.

8. The method of claim 1, further comprising: The step of providing a housing comprises providing the support with an engagement face for engaging the circuit board, wherein the engagement face comprises at least one of a heat sink face for conducting heat away from the circuit board and a ground face for grounding the circuit board. The step of adjusting the position of the circuit board comprises aligning the active area with a projected image projected onto the known image location using a projector.

9. Manufacturing equipment for use in a method according to any one of claims 1 to 8, the manufacturing equipment comprising one or more manipulators and a controller configured to control the one or more manipulators to align the active area with the image location.

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