Actively selects the lens used in the camera focusing process.

Abstract

This disclosure relates to the active selection of lenses used in the camera focusing process. Lenses used during camera assembly are selected based on whether their pairing with a specific set of production components meets the focusing performance criteria for end-of-line (EOLT) testing. Testing equipment can inspect the lenses by dry-fitting them with the specific set of production components. If minimum focusing performance cannot be achieved, a different set of lenses is used with that set of production components to produce the final camera assembly. In this way, because lenses are actively selected during production to achieve satisfactory EOLT focusing performance, each final camera assembly is more likely to pass EOLT, thereby improving camera production output.

Description

Background Technology

[0001] Cameras are common in vehicles and used for a variety of purposes; images can be used alone or in combination with data from other sensors to enable advanced safety features and semi-autonomous or even fully autonomous control. Modulation transfer function (MTF) is a performance measure of a camera system. A camera's MTF depends on the ability of its focusing lens. Achieving a specific MTF performance can be a critical requirement for the final camera assembly. Modular alignment and testing (CMAT) equipment can be used to check the focusing capability of a set of lenses before they are used in production. However, the focusing capability of a lens can change from one camera to the next due to minute variations in the adhesive that alters the lens's focusing capability or other minor final assembly conditions. Even if a lens meets the initial MTF check, the MTF performance measured by an end-of-line tester (EOLT) may be insufficient due to changes that occur during the final assembly process (e.g., integration of the lens with production components). Summary of the Invention

[0002] This document describes one or more aspects of actively selecting lenses for a camera focusing process. In one example, a method includes a set of camera parts and a corresponding set of lenses, identified by a processor of a Camera Modular Alignment and Test (CMAT) apparatus for use in producing a portion of a final camera assembly. The method further includes the processor controlling the CMAT apparatus to: dry-mate the lenses with the camera parts and perform an initial five-axis lens alignment check, the initial five-axis lens alignment check measuring the initial modulation transfer function (MTF) performance of the lenses when dry-mated with the camera parts. The method further includes the processor determining whether the initial MTF performance meets an MTF threshold, and in response to determining that the initial MTF performance meets the MTF threshold, further controlling the CMAT apparatus to: apply an adhesive material to an interface on a surface of the camera parts; dry-mate the lenses with the camera parts after the adhesive material has been applied; and perform a subsequent five-axis lens alignment check measuring the subsequent MTF performance of the lenses when dry-mated with the camera parts after the adhesive material has been applied. The method further includes controlling the CMAT equipment to: if subsequent MTF performance meets the MTF threshold, then cure the adhesive material for use in the output of the final camera assembly.

[0003] The techniques described herein (including any described processes and methods) can be performed by hardware or a combination of hardware and software executing thereon. For example, a computer-readable storage medium may have instructions stored thereon, which, when executed, configure a processor to perform the described processes, methods, and techniques. A system may include means for performing the described methods, processes, and techniques. A processor or processor unit may be part of a system configured to perform the methods, processes, and techniques described herein.

[0004] This invention is provided to describe various aspects of actively selecting lenses for camera focusing processes, which will be further described in the following detailed description section and the accompanying drawings. This summary section is not intended to identify essential features of the claimed subject matter, nor is it intended to define the scope of the claimed subject matter. Attached Figure Description

[0005] This document describes in detail the active selection of lenses used in the camera focusing process with reference to the accompanying drawings. The drawings may use the same numbers to refer to similar features and components, and hyphenated numbers to specify variations of these similar features and components. The drawings are organized as follows:

[0006] Figures 1-1 to 1-4 A conceptual diagram of an example camera assembly according to the technology of this disclosure is shown, for which the lens used for the camera focusing process can be actively selected;

[0007] Figure 2-1 , Figure 2-2 and Figure 2-3 A conceptual diagram illustrating a method of focusing a camera assembly based on the lens position and / or orientation relative to an image sensor, according to the technology of this disclosure;

[0008] Figure 3 A flowchart is shown of a conventional computer control process for focusing a camera assembly without an active selection lens, according to the technology of this disclosure;

[0009] Figure 4-1 and Figure 4-2 A flowchart is shown of a computer control process for focusing a camera assembly by actively selecting a lens according to the technology of this disclosure; Detailed Implementation

[0010] introduction

[0011] Using high-quality lenses or other high-quality components does not guarantee a high-quality camera. Appropriate camera components are crucial for ensuring the desired MTF (Mean Transmission Frequency) for high-quality imaging. Finding ways to produce high-quality camera components with less waste and less time can reduce costs, allowing more vehicles to adopt these high-quality camera components to improve driving and safety. High-quality camera components minimize angle-to-angle image variation while maintaining a balance between center and angular image values ​​and / or ensuring camera focus quality to preserve image quality over long-term use. High-quality camera components incorporating these and other characteristics are what vehicle use demands.

[0012] To achieve high quality, care must be taken when selecting components for camera assemblies. Inspecting and selecting lenses with appropriate functionality can be a complex and time-consuming task. For example, lenses can be inspected through a process called dry-fit testing. Each lens is inspected using a common test fixture that simulates the production lens barrel and printed circuit board (PCB) assembly used in camera assembly production. The test fixture is fed into a testing machine (such as a CMAT apparatus), which performs a computer-controlled check of the lens's focusing capability while positioned within the fixture. This process requires manual (e.g., by an operator) loading of the CMAT each time a camera component (e.g., a lens assembly) is in testing. Approximately one-third of lenses typically fail this dry-fit test. Lenses that pass this test are allowed for use in the final assembly. Lenses that fail the test are discarded or returned to the manufacturer. Typically, the results of the dry-fit test are not correlated with data from the lens supplier. Dry-fitting lenses before camera production or final assembly maximizes the likelihood that the produced camera assembly will meet EOLT requirements.

[0013] EOLT inspection is performed on each final camera assembly manufactured using lenses that have passed the initial CMAT test. While CMAT checks lens performance against the minimum requirements established by EOLT, simply utilizing CMAT's dry fit does not guarantee passing EOLT. Variations within the manufacturing barrel or PCB assembly can cause some camera assemblies to fail EOLT requirements compared to the test fixture, even though these camera assemblies meet CMAT inspection. In the final assembly, lens orientation, PCB mounting to the barrel, PCB variations, and tray variations can cause misalignment. Manufacturing variations in lens position and / or orientation (e.g., tilt-orientation, height-orientation) can reduce MTF and lead to failure during the final EOLT test.

[0014] Failures at the EOLT are unrecoverable; if the camera assembly fails to meet the minimum requirements of the EOLT, the entire camera assembly may be scrapped. If the EOLT fails, camera components (including PCB components) cannot be saved; replacement parts may be very expensive and difficult to obtain. If the final camera assembly and its internal components are forced to scrap at a high rate, consistent production of camera assemblies becomes difficult to achieve.

[0015] This document describes a technique for actively selecting lenses for the camera focusing process. Instead of manually pre-sorting lenses using CMAT equipment before production for dry-fit testing against common test fixtures, the described technique involves actively selecting each lens group to be used during final assembly based on whether their pairing with a specific production part set meets the MTF performance criteria for EOLT. For example, as part of the camera assembly process, CMAT equipment may be loaded with lenses, lens barrels, and other camera components to assemble a camera assembly. CMAT equipment can inspect lens groups that are dry-fitted with a specific production part set. If minimum MTF performance cannot be achieved through pairing, the lens will not be used to complete the camera assembly; instead, different lens groups already loaded into CMAT equipment are dry-fitted with that specific production part set to generate the final camera assembly for EOLT. In this way, because lenses are actively selected during production to achieve satisfactory MTF performance with the actual production parts of the final camera assembly, each final camera assembly is likely to pass the EOLT focusing check, thereby improving production output.

[0016] Example camera component

[0017] Figures 1-1 to 1-4 A conceptual diagram of an example camera assembly according to the technology of this disclosure is shown, for which the lens used for the camera focusing process can be actively selected. Figure 1-1 The image shows an exploded view of camera assembly 100. Camera assembly 100 is formed of multiple parts, including a lens barrel 102 configured to hold one or more lenses 112, an adhesive material 104 configured to bond the lens barrel 102 to a housing 106 to provide structural and environmental protection to the components of camera assembly 100, and a gasket 108 configured to connect the housing 106 to a PCB assembly 110, the PCB assembly 110 including an image sensor 116 disposed on a PCB 114.

[0018] Figure 1-2An assembled view of the camera assembly 100 is shown, in which multiple parts are arranged in a final assembled manner. The lens barrel 102 is partially inserted into an opening in the housing 106. When the adhesive material 104 cures, the adhesive material 104 secures the lens barrel 102 to the housing 106, which is bonded to a gasket 108 that protects the components of the PCB assembly 110 disposed therein.

[0019] Figure 1-3 A cross-sectional view of camera assembly 100 is shown. Within lens barrel 102, one or more lenses 112 (e.g., lens assemblies) are stacked above PCB assembly 110. PCB assembly 110 includes PCB 114, and among the components on PCB 114, PCB assembly 110 includes image sensor 116 (e.g., imager). Lenses 112 are positioned above image sensor 116, and processing units (e.g., hardware and / or software) executing on PCB 114 control image sensor 116 for capturing objects in the field of view.

[0020] Figure 1-4 A close-up cross-sectional view of the camera assembly 100 is shown. The lens barrel 102 includes a lens 112 positioned above an image sensor 116 on a PCB 114 of the PCB assembly 110. The lens barrel 102 is adhered to a housing 106 using a cured adhesive material 104. The lens barrel 102 may have an attached filter (e.g., an infrared filter). A gasket 108 seals the lens barrel 102 (including any filter) within the housing 106.

[0021] It is crucial that the components of camera assembly 100 are precisely assembled and fitted. Otherwise, camera assembly 100 may fail at the EOLT. If camera assembly 100 fails the EOLT, it cannot be recovered, and the entire camera assembly 100 may be scrapped. Failure to pass the EOLT can result in the waste of image sensor 116, PCB 114, lens 112, gasket 108, housing 106, adhesive material 104, and lens barrel 102, leading to significant time and resource waste. Obtaining replacement parts to build new replacement camera assemblies for those that fail the test can be both difficult and expensive; many of these parts are expensive or in short supply. Ensuring the precise assembly and matching of the components of camera assembly 100 before the EOLT ensures that camera assembly 100 passes, which is important for achieving consistent production output with a low scrap rate.

[0022] Lens positioning for improving MTF

[0023] Figures 2-1 to 2-3 A conceptual diagram illustrates how camera components are focused based on lens position and / or orientation relative to the image sensor. Figures 2-1 to 2-3In each of the figures, the lens 112 of the camera assembly 100 is shown in different positions and orientations relative to the image sensor 116 and the PCB 114.

[0024] Figure 2-1 Scene 200-1 is illustrated, in which the amount of tipping or tilting associated with lens 112 can affect focusing and MTF performance to produce images 202-1, 202-2, or 202-3. In scene 200-1, lens 112 is oriented above image sensor 116 at different tilt angles relative to the Z-axis, which is perpendicular to the XY plane corresponding to the surface of image sensor 116. When lens 112 is oriented with zero tilt or zero tipping relative to image sensor 116, image 202-1 is slightly out of focus. In contrast, with a positive tilt relative to the Z-axis, lens 112 makes image 202-2 appear more out of focus than image 202-1. However, with a negative tilt relative to the Z-axis, lens 112 makes image 202-3 more focused than either image 202-1 or image 202-2.

[0025] Figure 2-2 Different scenarios 200-2 are illustrated, showing the amount of separation between lens 112 and image sensor 116 to alter focus and MTF performance, generating images 202-4, 202-5, or 202-6. When lens 112 is oriented above image sensor 116 at a first distance from its surface, image 202-4 is out of focus. When lens 112 is oriented above image sensor 116 at a shorter distance than the first distance, image 202-5 is even more out of focus than image 202-4. However, at a second position above the imager, neither as far as the first distance nor as close as the shorter distance, lens 112 makes image 202-6 appear focused.

[0026] exist Figure 2-3The third scene 200-3 is depicted. Scene 200-3 illustrates how the offset between the centerline 204 of lens 112 and image sensor 116 can affect the focusing and MTF performance when producing images 202-7, 202-8, or 202-9. In scene 200-3, lens 112 is oriented above image sensor 116 with a first distance offset from image sensor 116, and image 202-7 is missing a portion 206-1 of the field of view. When lens 112 is oriented above image sensor 116 and centerline 204 is aligned with image sensor 116 (e.g., zero offset), image 202-8 is improved compared to image 202-7; however, portion 206-2 is still omitted, thus limiting what would otherwise be observable in the field of view. However, with a small offset between the centerline 204 of lens 112 and image sensor 116, lens 112 allows image 202-9 to capture the entire field of view without omitting either of the portions 206-1 or 206-2 that were omitted from images 202-7 and 202-8.

[0027] Scenes 200-1 to 200-3 demonstrate that the positioning and orientation of lens 112 relative to image sensor 116 are important for ensuring sufficient focus and satisfactory MTF for EOLT throughput. This also indicates that adjusting the orientation and positioning of lens 112 relative to image sensor 116 during assembly when producing camera assembly 100 can significantly improve EOLT throughput.

[0028] Existing assembly processes without actively selecting lenses

[0029] Figure 3 A flowchart of a conventional computer-controlled process 300 for focusing a camera assembly without the described active selection lens, according to the technology of this disclosure, is shown. Process 300 in Figures 1-1 to 1-4 and Figures 2-1 to 2-2 As described in the context of the test apparatus, as if performed by the test apparatus, the test apparatus includes at least one processor configured to perform the steps of the process 300 and / or means for performing the steps of the process 300.

[0030] Process 300 includes an initial lens sorting step 302, followed by a subsequent camera production step 304. In the lens sorting step 302, an MTF check 306 precedes the lens storage 308 for subsequent production.

[0031] During MTF inspection 306, the focusing performance of lens 112 is individually inspected using CMAT equipment and a static test structure. For example, as depicted in scenes 200-1 to 200-3, lens 112 is inspected by moving it relative to image sensor 116.

[0032] A static test structure is constructed to replicate camera assembly 100 or portions thereof for testing the fit and function of different batches of lenses 112 with production parts in the final assembly. Each set of lenses 112 is manually loaded into the test structure (e.g., individually by an operator). The static test structure may be a production version of camera assembly 100, except for the lenses 112. Components of the test structure may be locked in place (e.g., using adhesives, mechanical interfaces), but no adhesive is used for the lenses 112. Unlike the actual production version of camera assembly 100 in which the lenses 112 are fixed, the static test structure is configured to allow the removal and replacement of lenses 112 from one test to the next.

[0033] The static test structure replicates the operating environment of lens 112 to enable CMAT equipment to consistently examine focusing capability. Included in the static test structure is a replica of at least a portion of lens barrel 102, within which the lens 112 under test is located. Below lens barrel 102 is a replica of at least a portion of PCB assembly 110, including image sensor 116, and some or all of PCB 114. The relative positions of the components of the static test structure can be moved during testing, for example, to examine the increase or decrease in MTF of lens 112 when it is in different positions or orientations relative to image sensor 116. For example, as... Figures 2-1 to 2-3 As shown, MTF inspection 306 may include repositioning or reorienting lens 112 to determine whether lens 112 is likely to meet MTF requirements when mated with production parts during final assembly.

[0034] During MTF inspection 306, the CMAT equipment tests each lens group 112 mounted on the test structure according to the MTF performance requirements determined by EOLT. Taking into account the dry fit inspection of the lenses 112, the results of MTF inspection 306 can be used to distinguish lenses 112 that do not meet the minimum MTF performance requirements from those that pass MTF inspection 306. For example, using a five-axis lens alignment mode for MTF performance testing, the acceptable MTF performance measurement at the center MTF_0 of the lens 112 can be greater than 70%, and the acceptable MTF performance measurements at the corners MTF_1 to MTF_4 of the lens 112 can be greater than 50%.

[0035] The result of MTF inspection 306 is lens storage 308, in which the lenses 112 that passed MTF inspection 306 are maintained until they are ready for assembly and focusing for production. Lens storage 308 may attempt to maintain the lenses 112 in the exact position and orientation they were in during MTF inspection 306; this allows the same lens positioning or orientation to be applied to the production of camera assembly 100, increasing the likelihood that camera assembly 100 can withstand the careful inspection of EOLT during camera production step 304.

[0036] During camera production step 304, after plasma treatment 310 of the components, there is epoxy resin dispensing 312, five-axis lens alignment 314, and finally UV curing 316 before undergoing EOLT 318. At this stage, the production components for building camera assembly 100, including lens 112 and at least a portion of housing 106 (comprising lens barrel 102 and PCB assembly 110), are loaded into the CMAT equipment. Adhesive material 104 is also loaded into the CMAT equipment.

[0037] Plasma treatment 310 cleans any interface surfaces of components loaded into CMAT equipment. Cleaning is performed using a plasma cleaning process.

[0038] Epoxy resin dispensing 312 applies adhesive material 104 to the interface between lens barrel 102 and PCB assembly 110 to configure the portion of PCB assembly 110 responsible for contacting the lens (e.g., image sensor 116) to be operable when lens 112 is mounted.

[0039] Five-axis lens alignment 314 includes positioning lens 112 within lens barrel 102 and above PCB assembly 110, followed by a step-through CMAT focusing process until MTF requirements are met. For example, this process involves using position and orientation measurements taken during lens sorting step 302 to guide lens repositioning and reorientation during CMAT inspection. If the MTF requirements are not met after a maximum number of attempts, lens 112 and housing 106, including PCB assembly 110 and lens barrel 102, are rejected and scrapped.

[0040] If the camera assembly 100 is aligned with the five-axis lens 314, ultraviolet curing 316 is performed. During this stage, ultraviolet light is applied to the camera assembly 100 to harden the adhesive material 104 and hold the lens 112 in place relative to the PCB assembly 110.

[0041] After curing, EOLT 318 occurs. Each of the production camera assemblies is tested according to MTF requirements. If camera assembly 100 fails this test, the entire unit is discarded.

[0042] Therefore, process 300 and other existing assembly processes that do not utilize the technology of this disclosure to actively select lenses have some drawbacks or limitations. Lens sorting step 302 is labor- and time-intensive (e.g., this increases manufacturing costs); however, it is an important condition for camera production step 304 because it minimizes waste. Typically, the measurements performed by the manufacturer of lens 112 are not related to the expected MTF performance measured during MTF inspection 306, five-axis lens alignment 314, or EOLT 318. Without sorting, process 300 may result in a high rate of unusable camera assemblies or unusable parts thereof. Even so, lens sorting step 302 may not be a reliable way to obtain high-quality camera assemblies at camera production step 304 due to variations in test structures and production components, and wasted components during EOLT 318 can be quite common. Obtaining replacement parts to manufacture further assemblies can be difficult, potentially leading to delays and inconsistent production rates and / or production costs.

[0043] Example assembly process including active selection lens

[0044] Figure 4-1 A flowchart of a computer-controlled process 400 for focusing a camera assembly via an actively selected lens, according to the technology of this disclosure, is shown. Process 400 in... Figures 1-1 to 1-4 and Figures 2-1 to 2-3 Described in the context of [the process 400], as performed by a test apparatus, the test apparatus includes at least one processor configured to perform steps of process 400 and / or means for performing steps of process 400. The operations (also referred to as steps) of process 400 are numbered; however, this numbering does not necessarily imply a specific order of operations. The steps of process 400 can be [discussed in conjunction with...]. Figure 4-1 The diagram shows different ways to rearrange, skip, repeat, or execute specific methods.

[0045] Process 400 includes plasma treatment 402, followed by initial five-axis lens alignment 404. After the initial five-axis lens alignment 404, a determination 406 is made regarding the acceptability of lens 112. If lens 112 is acceptable, epoxy resin dispensing 408 occurs prior to subsequent five-axis lens alignment 404. Then, UV curing 410 occurs before the final assembly is inspected at EOLT 412.

[0046] For example, similar to camera production step 304, the CMAT equipment can be loaded with production parts to build camera assembly 100. In other words, the CMAT equipment can load multiple sets of camera parts and multiple sets of corresponding lenses, instead of pre-sorting the lenses or camera parts and manually loading them one at a time for inspection using a test fixture. This can include multiple trays for loading lenses 112, portions of housing 106 containing lens barrel 102 and PCB assembly 110, and adhesive material 104. Plasma treatment 402 cleans any interface surfaces of the parts loaded into the CMAT equipment. Cleaning uses a plasma cleaning process. Next, unlike process 300 where epoxy resin is applied 312 before five-axis lens alignment 314, the five-axis lens alignment 404 in process 400 occurs before any adhesive is applied; the five-axis lens alignment 404 is dry-fit.

[0047] At time 1, five-axis lens alignment 404 can be performed by a CMAT apparatus to measure the MTF performance of a specific set of lenses 112 used in a production version of camera assembly 100 with a specific lens barrel 102 and a specific PCB assembly 110. For example, the CMAT apparatus loads a specific set of lenses 112 into a specific production version of lens barrel 102 to check their combined focusing capability when paired with a specific production version of PCB assembly 110 (or a portion thereof). The CMAT apparatus is then configured to reposition the lenses 112 and / or lens barrel 102 relative to PCB assembly 110. Repositioning the lenses 112 and / or lens barrel 102 may include adjusting the distance (e.g., height) separating PCB assembly 110 from lenses 112 and / or lens barrel 102, adjusting the offset between the respective centerlines of PCB assembly 110 and lenses 112 and / or lens barrel 102, or adjusting the amount of tilt applied to lenses 112 and lens barrel 102 relative to the detection plane of PCB assembly 110. By performing five-axis lens alignment 404 and testing different positions and tilts of lens 112 to maximize MTF performance, the appropriate position and tilt angle of the lens group 112 relative to the PCB assembly 110 can be inferred by the CMAT equipment.

[0048] The positioning and / or tilting of lens 112 can be adjusted incrementally during five-axis lens alignment 404. Adjustments may begin with large steps (e.g., twelve micrometers). In response to achieving satisfactory MTF performance by adjusting the position and / or tilt in large steps, the CMAT apparatus can further adjust the positioning and / or tilt in small steps (e.g., four micrometers). This makes it possible to determine the optimal position and tilt of lens 112 for that particular lens barrel 102 and that particular PCB assembly 110.

[0049] Next, at time 2, a determination 406 is made regarding whether the MTF performance of the combination of lens 112 with a specific lens barrel 102 and a specific PCB assembly 110 meets the MTF requirements of the final assembly. If the minimum MTF performance can be achieved during five-axis lens alignment 404 (e.g., dry fit), parameters for the final assembly using lens 112 are stored. This includes storing the distance (e.g., height) between lens 112 and PCB assembly 110, the offset or orientation (e.g., tilt) of lens 112 relative to PCB assembly 110, and other parameters.

[0050] Lenses 112 are accepted by decision 406 and proceed to the assembly stage using their parameters and matching lens barrels and PCB assemblies. Lenses 112 that do not meet MTF performance requirements can be discarded. Five-axis lens alignment 404 can be repeated until MTF performance requirements are met or the maximum number of adjustments or attempts is reached. Because process 400 includes this dry-fit lens alignment check, there may be less waste of lens barrel 102 and / or PCB assembly 110 if lens 112 cannot be reoriented or repositioned with another set of production parts to achieve satisfactory MTF performance. If lens 112 is rejected, a different set of lenses 112 can be tried using lens barrel 102 and PCB assembly 110.

[0051] Epoxy resin dispensing 408 occurs based on decision 406. Lens 112 is removed from its position, and the CMAT apparatus applies adhesive material 104 to the mating surfaces of lens barrel 102 and / or PCB assembly 110. Lens 112 is reinstalled in lens barrel 102, now mating with PCB assembly 110. Using the appropriate positioning and tilt angle deduced from the five-axis lens alignment 404 that occurred earlier at time 1, lens 112 is positioned and oriented relative to PCB assembly 110.

[0052] However, at time 3, the five-axis lens alignment 404 is performed again. Because lens 112 can be aligned from an earlier deduced position and orientation, the five-axis lens alignment 404 can occur faster than the five-axis lens alignment 404 that occurs at time 1. Lens 112 can be positioned above PCB assembly 110 to perform the five-axis lens alignment and focusing performance process. The position and orientation of lens 112 can be fine-tuned to rapidly step through the focusing process until the MTF requirement is met or the maximum number of steps is reached. If camera assembly 100 fails the test here, lens 112 and the components used to test lens 112 are rejected and scrapped. This may occur less frequently due to the dry fit of components that occurred at time 1.

[0053] At time 4, if camera assembly 100 is aligned with the five-axis lens 404, UV curing 410 is performed. During this stage, UV irradiation is applied to camera assembly 100 to harden the adhesive material 104 applied to the interface of camera assembly 100 during epoxy resin dispensing 408, for example, to hold lens 112 in place relative to the lens barrel relative to PCB assembly 110. After UV curing 410, EOLT 412 occurs. Camera assembly 100 is ultimately tested according to MTF requirements. If camera assembly 100 ultimately fails the test at EOLT 412, the entire unit is discarded.

[0054] Therefore, by actively selecting lenses 112 that are likely to pass the MTF test using CMAT equipment and ensuring that components remain aligned before curing, process 400 can result in less waste and less time compared to other processes, such as process 300. When compared to existing camera assembly technologies, process 400 can achieve significant reductions in production costs and time and / or improvements in quality. Process 400 omits the labor- and time-intensive lens sorting step 302, yet still results in less waste and improved quality. CMAT equipment checks the MTF performance of lens 112 as part of the assembly process of camera assembly 100; it tests the focusing capability of lens 112 using specific production components that will be used with lens 112. Compared to process 300, process 400 can result in a lower rate of unusable camera components or a higher rate of usable camera components, thereby improving production quality.

[0055] Figure 4-2 A flowchart of a computer-controlled process 414 for actively selecting lenses to focus a camera assembly according to the technology of this disclosure is shown. Process 414 illustrates the active selection of lenses for the camera focusing process, including lenses to be used during camera assembly, based on whether their pairing with a specific set of production parts can meet the focusing performance criteria of the end-of-line test (EOLT). Test equipment can execute process 414 to inspect the lenses by dry-fitting them with the specific set of production parts. If minimum MTF performance cannot be achieved, a different set of lenses and that set of production parts are used to produce the final camera assembly. In this way, because lenses are actively selected during production to achieve satisfactory MTF performance for the EOLT, each final camera assembly is more likely to pass the EOLT from process 414, thereby improving camera production output.

[0056] Processor 414 can be executed by a processor of the CMAT equipment, which is configured to control the CMAT equipment to produce a portion of the final camera assembly (such as camera assembly 100). The processor can retrieve instructions maintained by the CMAT equipment in memory or a computer-readable storage medium. When the instructions are executed, these instructions configure the processor to perform process 414 by controlling components of the CMAT equipment, as described below.

[0057] At 416, identifiers have been loaded into the lens and camera components in the CMAT equipment configured for the production of the final camera assembly. For example, in addition to lens 112, the processor of the CMAT equipment can identify lens barrel 102 and PCB assembly 110, each of which is loaded into the CMAT equipment for the production of a portion of camera assembly 100.

[0058] At 418, the CMAT equipment is controlled to dry-mate the lens with the camera components. For example, the processor of the CMAT equipment causes the components of the CMAT equipment to dry-mate the lens 112 with the camera components (including lens barrel 102, image sensor 106, PCB 114, or other components of camera assembly 100). No adhesive material or epoxy resin is used at this time.

[0059] At 420, an initial five-axis alignment check measures the initial MTF performance of the lens when dry-fitted with the camera component. For example, the processor of the CMAT equipment can perform a first dry-fit alignment (e.g., five-axis lens alignment 404), which measures the initial MTF performance of the lens 112 by coarsely adjusting the position or orientation of the lens 112 or camera component (e.g., lens barrel 102, PCB assembly 110). Following the first dry-fit alignment, the processor of the CMAT equipment can perform a second dry-fit alignment. The second dry-fit alignment further measures the initial MTF performance of the lens 112 by finely adjusting the position or orientation of the lens 112 or camera component. Each fine adjustment is smaller than each coarse adjustment. The alignment parameters obtained from the second dry-fit alignment, which include the position or orientation of the dry-fitted lens and camera component to achieve MTF performance meeting an MTF threshold, can be maintained by the processor of the CMAT equipment before the application of adhesive material 104.

[0060] In some examples, as a result of step 420, the processor of the CMAT apparatus maintains alignment parameters for the dry-fitted lens 112 that satisfy the MTF threshold. These alignment parameters may include the height of the lens 112 relative to the image sensor 116 of the camera component and its tilt relative to both the lens 112 and the image sensor 116. At step 428, the processor can use the alignment parameters to perform a subsequent five-axis lens alignment check.

[0061] Although not shown for simplicity, in some examples, the processor controls the CMAT equipment to perform an initial five-axis lens alignment check after first controlling the CMAT equipment to clean the interface on the camera component surface and before dry-fitting the lens to the camera component. For example, the processor may cause plasma processing 402 to occur before step 420.

[0062] At step 422, it is determined whether the initial MTF performance meets the MTF threshold. For example, a "No" result from step 422 results in the lens being discarded and another set of lenses being tried with camera assembly 424. A "Yes" result from step 422 results in lens 112 being used to produce the final camera assembly 100 by performing step 426.

[0063] At 424, in response to determining that the initial MTF performance of the lens does not meet the MTF threshold, the processor can discard lens 112 from the CMAT equipment to prevent lens 112 from being used as part of the final camera assembly. Processor 414 returns to step 418, where the processor controls the CMAT equipment to replace lens 112 with a second set of lenses 112 for use in the production of the final camera assembly 100.

[0064] At 426, in response to determining that the initial MTF performance meets the MTF threshold, the processor can control the CMAT equipment to apply adhesive material to the interface on the surface of the camera component, and dry-fit the lens to the camera component after applying the adhesive material. For example, the processor controls the CMAT equipment to apply adhesive material 104 to the lens barrel 102 and PCB 114, as well as other components of the PCB assembly 110.

[0065] At 428, a subsequent five-axis lens alignment check is performed, which measures the subsequent MTF performance of the lens when dry-fitted with the camera component after the adhesive material has been applied. For example, the processor of the CMAT equipment can perform dry-fit alignment (e.g., five-axis lens alignment 404) while adhesive material 104 has been applied. Dry-fit alignment measures the initial MTF performance of lens 112 by coarsely and / or finely adjusting the position or orientation of lens 112 or camera component (e.g., lens barrel 102, PCB assembly 110).

[0066] The alignment parameters generated from the initial five-axis alignment performed at step 420 can be used in the case of subsequent five-axis lens alignment. The alignment parameters may include previously successful positions or orientations of the dry-fit assembled lens 112 and camera components that enable MTF performance before the application of adhesive material 104. When input into subsequent five-axis alignment checks, the alignment parameters can be used as initial settings to rapidly achieve the final assembled MTF performance by stepping through adjustments to the position or orientation of the dry-fit assembled lens 112 and camera components after the application of adhesive material.

[0067] At step 430, it is determined whether the subsequent MTF performance meets the MTF threshold. For example, the processor in the CMAT equipment checks whether the result of step 428 meets the final production MTF threshold. A "No" result from step 430 leads to step 432, while a "Yes" result proceeds to step 434.

[0068] At 432, in response to determining that the MTF performance of lens 112 and camera component does not meet the MTF threshold, the lens and camera component are discarded. For example, in the case where adhesive material is applied to camera component and lens 112, they are no longer suitable for reuse (e.g., without readjustment or further cleaning) and are removed from CMAT equipment.

[0069] However, at 434, in response to the determination that the MTF performance of lens 112 and camera components does indeed meet the MTF threshold, adhesive material is cured for use in the final output of the camera assembly. Adhesive material 104 secures lens 112 to lens barrel 102 and PCB assembly 110.

[0070] In some cases, after the CMAT equipment cures the adhesive material 104, the processor can check whether the subsequent MTF performance meets the MTF threshold. Process 414 further includes checking whether the final MTF performance of the lens 112 meets the MTF threshold. A portion of the final camera assembly 100 produced by process 414 can be discarded. In response to determining that the final MTF performance of the lens does not meet the MTF threshold, the processor can cause the CMAT equipment to avoid outputting a portion of the final camera assembly for final production.

[0071] Further examples

[0072] Further examples of the above technologies include:

[0073] Example 1. A method comprising: a set of camera parts and a corresponding set of lenses, identified by a processor of a Camera Modular Alignment and Test (CMAT) apparatus for producing a portion of a final camera assembly; the CMAT apparatus being controlled by a controller to: dry-mate the lenses with the camera parts; and perform an initial five-axis lens alignment check, the initial five-axis lens alignment check measuring the initial modulation transfer function (MTF) performance of the lenses when dry-mated with the camera parts; the processor determining whether the initial MTF performance meets an MTF threshold; and in response to determining that the initial MTF performance meets the MTF threshold, further controlling the CMAT apparatus to: apply an adhesive material to an interface on a surface of the camera parts; dry-mate the lenses with the camera parts after the adhesive material has been applied; perform a subsequent five-axis lens alignment check measuring the subsequent MTF performance of the lenses when dry-mated with the camera parts after the adhesive material has been applied; and if the subsequent MTF performance meets the MTF threshold, curing the adhesive material for outputting a portion of the final camera assembly.

[0074] Example 2. The method of Example 1 further includes: identifying a set of second camera components and a corresponding set of second lenses loaded into a CMAT equipment for use in the production of a second final camera assembly; the processor controlling the CMAT equipment to perform an initial five-axis lens alignment check, the initial five-axis lens alignment check measuring the initial MTF performance of the second lens when dry-fitted with the second camera components; and in response to determining that the initial MTF performance of the second lens does not meet an MTF threshold, the controller controlling the CMAT equipment to replace the second lens with a third lens for use in the second final camera assembly.

[0075] Example 3. The method of any of the foregoing examples further includes: the processor controlling a CMAT apparatus to perform an initial five-axis lens alignment check, the initial five-axis lens alignment check measuring the initial MTF performance of the third lens when dry-fitted with a second camera component; and in response to determining that the initial MTF performance of the third lens meets an MTF threshold, the processor controlling the CMAT apparatus to: dry-fit the third lens with the second camera component after the interface of the second adhesive material being applied to the surface of the second camera component; and to perform a subsequent five-axis lens alignment check measuring the subsequent MTF performance of the third lens when dry-fitted with the second camera component after the application of the second adhesive material; and if the subsequent MTF performance of the third lens meets the MTF threshold, to cure the second adhesive material for use in the production of a portion of the second final camera assembly.

[0076] Example 4. The method of any of the foregoing examples further includes: in response to determining that the initial MTF performance of the second lens does not meet the MTF threshold, discarding the second lens from the CMAT equipment to prevent the second lens from being identified as a part for the production of a third final camera assembly.

[0077] Example 5. The method of any of the foregoing examples further includes: in response to determining that the initial MTF performance meets the MTF threshold, the processor maintains alignment parameters of the dry-fitted lens that meet the MTF threshold, wherein the alignment parameters are used by the processor to perform a subsequent five-axis lens alignment check.

[0078] Example 6. The method of any of the preceding examples, wherein the alignment parameters include the height of the lens relative to the image sensor of the camera component and the tilt relative to the lens and the image sensor.

[0079] Example 7. A method of any of the preceding examples, wherein controlling the CMAT equipment to perform an initial five-axis lens alignment check includes: performing a first dry-fit alignment, the first dry-fit alignment measuring the initial MTF performance of the lens by coarsely adjusting the position or orientation of the lens or camera component; performing a second dry-fit alignment measuring the initial MTF performance of the lens by finely adjusting the position or orientation of the lens or camera component, each of the fine adjustments including a smaller adjustment amount than each of the coarse adjustments; and maintaining alignment parameters obtained from the second dry-fit alignment, the alignment parameters including the position or orientation of the dry-fit assembled lens and camera component to achieve MTF performance meeting an MTF threshold before the application of adhesive material.

[0080] Example 8. A method of any of the preceding examples, wherein controlling the CMAT equipment to perform a subsequent five-axis lens alignment check includes: obtaining alignment parameters obtained from a second dry-fit alignment; and controlling the CMAT equipment to perform a third dry-fit alignment, the third dry-fit alignment measuring the subsequent MTF performance of the lens when dry-fitted with a camera component after the application of adhesive material, the third dry-fit alignment being performed by using the alignment parameters as initial settings for stepping adjustments to the position or orientation of the dry-fitted lens and camera component to achieve MTF performance that meets an MTF threshold after the application of adhesive material.

[0081] Example 9. A method of any of the preceding examples, wherein controlling the CMAT equipment to perform an initial five-axis lens alignment check includes controlling the CMAT equipment to clean the interface on the surface of the camera component before dry-fitting the lens with the camera component.

[0082] Example 10. The method of any of the foregoing examples, wherein after curing the adhesive material if the subsequent MTF performance meets the MTF threshold, the method further includes: checking whether the final MTF performance of the lens meets the MTF threshold; and in response to determining that the final MTF performance of the lens does not meet the MTF threshold, avoiding the output of a portion of the final camera assembly for final production.

[0083] Example 11. A method of any of the preceding examples, wherein performing the method facilitates the fabrication of the camera assembly prior to performing line-end testing.

[0084] Example 12. A method of any of the preceding examples, wherein the method further includes outputting a camera component after performing a line-end test.

[0085] Example 13. A system comprising means for performing the method of any of the preceding examples.

[0086] Example 14 A system including a processor configured to perform a method of any of the preceding examples.

[0087] Example 15. A computer-readable medium comprising instructions that, when executed, cause a processor to perform any of the methods described in the preceding examples.

[0088] Conclusion

[0089] While various embodiments of the present disclosure have been described in the foregoing description and illustrated in the accompanying drawings, it should be understood that the present disclosure is not limited thereto, but can be practiced in various ways within the scope of the following claims. It will be apparent from the foregoing description that various modifications can be made without departing from the scope of the present disclosure as defined by the following claims. Similar problems associated with assembling other types of sensors may also occur, in addition to camera systems. Therefore, although described as being for improving the performance of camera components, the techniques described in the foregoing specification can be adopted and applied to other problems to efficiently assemble high-precision sensor devices at low cost.

[0090] Unless the context explicitly states otherwise, the use of "or" and grammatically related terms indicates an unrestricted, non-exclusive alternative. As used herein, the phrase referring to "at least one" of a list of items means any combination of those items, including a single member. As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

Claims

1. A method for a camera, the method comprising: A set of camera components and a corresponding set of lenses are loaded into the CMAT equipment by the processor identifier of the camera modular alignment and testing equipment for the production of a portion of the final camera assembly. The processor controls the CMAT equipment for: The lens is dry-fitted and assembled with the camera component; as well as An initial five-axis lens alignment check is performed, wherein the initial five-axis lens alignment check measures the initial modulation transfer function (MTF) performance of the lens when it is dry-fitted with the camera component. The processor determines whether the initial MTF performance meets the MTF threshold. as well as In response to determining that the initial MTF performance meets the MTF threshold, the CMAT equipment is further controlled to: An interface for applying adhesive material to the surface of the camera component; After the adhesive material is applied, the lens is dry-fitted with the camera component. Perform a subsequent five-axis lens alignment check, which measures the subsequent MTF performance of the lens when it is dry-fitted with the camera component after the adhesive material has been applied; as well as If the subsequent MTF performance meets the MTF threshold, the adhesive material is cured to produce the portion of the final camera assembly.

2. The method of claim 1, further comprising: A set of second camera components and a corresponding set of second lenses are identified and loaded into the CMAT equipment for use in the production of a second final camera assembly. The processor controls the CMAT equipment to perform an initial five-axis lens alignment check, which measures the initial MTF performance of the second lens when it is dry-fitted with the second camera component. as well as In response to determining that the initial MTF performance of the second lens does not meet the MTF threshold, the processor controls the CMAT equipment to replace the second lens with a third lens for use in the second final camera assembly.

3. The method of claim 2, further comprising: The processor controls the CMAT equipment to perform an initial five-axis lens alignment check, which measures the initial MTF performance of the third lens during dry-fit assembly with the second camera component; and In response to determining that the initial MTF performance of the third lens meets the MTF threshold, the processor controls the CMAT equipment to: After the second adhesive material is applied to the interface on the surface of the second camera component, the third lens is dry-fitted with the second camera component. as well as Perform a subsequent five-axis lens alignment check, which measures the subsequent MTF performance of the third lens when it is dry-fitted with the second camera component after the second adhesive material is applied; as well as If the subsequent MTF performance of the third lens meets the MTF threshold, the second adhesive material is cured for use in the production of the portion of the second final camera assembly.

4. The method of claim 2, further comprising: Further in response to determining that the initial MTF performance of the second lens does not meet the MTF threshold, the second lens is discarded from the CMAT equipment to prevent the second lens from being identified as a part for the production of a third final camera assembly.

5. The method of claim 1, further comprising: Further in response to determining that the initial MTF performance meets the MTF threshold, the processor maintains the alignment parameters of the interferometrically assembled lens that meet the MTF threshold. The alignment parameters are used by the processor to perform the subsequent five-axis lens alignment check.

6. The method as described in claim 5, characterized in that, The alignment parameters include the height of the lens relative to the image sensor of the camera component and the tilt relative to the lens and the image sensor.

7. The method as described in claim 1, characterized in that, Controlling the CMAT equipment to perform the initial five-axis lens alignment check includes: Perform a first dry-fit alignment, which changes the position or orientation of the lens or camera component by coarsely adjusting the position or orientation of the lens or camera component, thereby measuring the initial MTF performance of the lens; Perform a second dry-fit alignment, which further alters the position or orientation of the lens or camera component by fine-tuning the position or orientation of the lens or camera component, thereby measuring the initial MTF performance of the lens, each of the fine-tunings comprising a smaller adjustment amount than each of the coarse-fittings; and Maintain alignment parameters obtained from the second dry-fit alignment, the alignment parameters including the position or orientation of the dry-fit assembled lens and camera components to achieve the MTF performance to meet the MTF threshold before the adhesive material is applied.

8. The method as described in claim 7, characterized in that, Controlling the CMAT equipment to perform the subsequent five-axis lens alignment check includes: Obtain the alignment parameters obtained from the second dry-fit alignment; and The CMAT equipment is controlled to perform a third dry-fit alignment, which measures the subsequent MTF performance of the lens when it is dry-fitted with the camera component after the adhesive material is applied. The third dry-fit alignment is performed by using the alignment parameters as initial settings to stepwise adjust the position or orientation of the dry-fitted lens and camera component after the adhesive material is applied by achieving the MTF performance to meet the MTF threshold.

9. The method as described in claim 1, characterized in that, Controlling the CMAT equipment to perform the initial five-axis lens alignment check includes controlling the CMAT equipment to clean the interface on the surface of the camera component before dry-fitting the lens with the camera component.

10. The method as described in claim 1, characterized in that, After curing the adhesive material if the subsequent MTF performance meets the MTF threshold, the method further includes: Check whether the final MTF performance of the lens meets the MTF threshold; and In response to determining that the final MTF performance of the lens does not meet the MTF threshold, the portion of the final camera assembly is avoided from being output for final production.

11. A computer-readable storage medium comprising instructions that, when executed, cause a processor of a camera modular alignment and testing CMAT apparatus to produce a portion of a final camera assembly by: The identification is loaded into the CMAT equipment for the production of the final camera assembly, comprising a set of camera components and a corresponding set of lenses; Controlling the CMAT equipment is used for: The lens is dry-fitted and assembled with the camera component; as well as An initial five-axis lens alignment check is performed, wherein the initial five-axis lens alignment check measures the initial modulation transfer function (MTF) performance of the lens when it is dry-fitted with the camera component. Determine whether the initial MTF performance meets the MTF threshold; as well as In response to determining that the initial MTF performance meets the MTF threshold, the CMAT equipment is further controlled to: An interface for applying adhesive material to the surface of the camera component; After the adhesive material is applied, the lens is dry-fitted with the camera component. Perform a subsequent five-axis lens alignment check, which measures the subsequent MTF performance of the lens when it is dry-fitted with the camera component after the adhesive material has been applied; as well as If the subsequent MTF performance meets the MTF threshold, the adhesive material is cured to produce the portion of the final camera assembly.

12. A system for a camera, the system comprising: A device for identifying a set of camera parts and a corresponding set of lenses that are loaded into the CMAT equipment for camera modular alignment and testing for use in the production of the final camera assembly. Device for controlling the CMAT equipment to perform the following operations: The lens is dry-fitted and assembled with the camera component; as well as An initial five-axis lens alignment check is performed, wherein the initial five-axis lens alignment check measures the initial modulation transfer function (MTF) performance of the lens when it is dry-fitted with the camera component. A means for determining whether the initial MTF performance meets the MTF threshold; as well as A means for further controlling the CMAT equipment to perform the following operations in response to determining that the initial MTF performance meets the MTF threshold: An interface for applying adhesive material to the surface of the camera component; After the adhesive material is applied, the lens is dry-fitted with the camera component. Perform a subsequent five-axis lens alignment check, which measures the subsequent MTF performance of the lens when it is dry-fitted with the camera component after the adhesive material has been applied; as well as If the subsequent MTF performance meets the MTF threshold, the adhesive material is cured to produce the portion of the final camera assembly.

13. The system of claim 12, further comprising: A means for identifying a set of second camera components and a corresponding set of second lenses loaded into the CMAT equipment for the production of a second final camera assembly; A device for controlling the CMAT equipment to perform an initial five-axis lens alignment check, the initial five-axis lens alignment check measuring the initial MTF performance of the second lens when dry-fitted with the second camera component; as well as A means for controlling the CMAT equipment to replace the second lens with a third lens for use in the second final camera assembly in response to determining that the initial MTF performance of the second lens does not meet the MTF threshold.

14. The system of claim 13, further comprising: A device for controlling the CMAT equipment to perform an initial five-axis lens alignment check, the initial five-axis lens alignment check measuring the initial MTF performance of the third lens when dry-fitted with the second camera component; as well as Means for controlling the CMAT equipment to perform the following operations in response to determining that the initial MTF performance of the third lens meets the MTF threshold: After the second adhesive material is applied to the interface on the surface of the second camera component, the third lens is dry-fitted with the second camera component. as well as Perform a subsequent five-axis lens alignment check, which measures the subsequent MTF performance of the third lens when it is dry-fitted with the second camera component after the second adhesive material is applied; as well as If the subsequent MTF performance of the third lens meets the MTF threshold, the second adhesive material is cured for use in the production of the portion of the second final camera assembly.

15. The system of claim 13, further comprising: A means for further responding to determining that the initial MTF performance of the second lens does not meet the MTF threshold and discarding the second lens from the CMAT equipment to prevent the second lens from being identified as a part for the production of a third final camera assembly.

16. The system of claim 12, further comprising: A means for further maintaining the alignment parameters of a dry-fitted lens that satisfy the MTF threshold in response to determining that the initial MTF performance satisfies the MTF threshold. The alignment parameters are used for the subsequent five-axis lens alignment check.

17. The system as claimed in claim 16, characterized in that, The alignment parameters include the height of the lens relative to the image sensor of the camera component and the tilt relative to the lens and the image sensor.

18. The system as claimed in claim 12, characterized in that, The device for controlling the CMAT equipment to perform the initial five-axis lens alignment check includes: A device for performing a first dry-fit alignment, wherein the first dry-fit alignment changes the position or orientation of the lens or camera component by coarsely adjusting the position or orientation of the lens or camera component, thereby measuring the initial MTF performance of the lens. A device for performing a second dry-fit alignment, which further alters the position or orientation of the lens or camera component by fine-tuning the position or orientation of the lens or camera component, thereby measuring the initial MTF performance of the lens, each of the fine-tunings comprising a smaller adjustment amount than each of the coarse-tunings; A means for maintaining alignment parameters obtained from the second dry-fit alignment, the alignment parameters including the position or orientation of the dry-fit assembled lens and camera components to achieve the MTF performance to meet the MTF threshold before the adhesive material is applied.

19. The system as claimed in claim 18, characterized in that, The device for controlling the CMAT equipment to perform the subsequent five-axis lens alignment check includes: A means for obtaining the alignment parameters obtained from the second dry-fit alignment; and A device for controlling the CMAT equipment to perform a third dry-fit alignment, the third dry-fit alignment measuring the subsequent MTF performance of the lens when it is dry-fitted with the camera component after the adhesive material is applied, the third dry-fit alignment being performed by using the alignment parameters as initial settings for step-by-step adjustments to the position or orientation of the dry-fitted lens and camera component to achieve the MTF performance to meet the MTF threshold after the adhesive material is applied.

20. The system of claim 12, further comprising: An apparatus for checking whether the final MTF performance of the lens meets the MTF threshold after curing the adhesive material if the subsequent MTF performance meets the MTF threshold; as well as Means for avoiding outputting the portion of the final camera assembly for final production in response to determining that the final MTF performance of the lens does not meet the MTF threshold.

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