Active alignment method based on image quality feedback ring, assembling and manufacturing method of camera module, and vehicle-mounted camera

Abstract

The invention provides an active alignment method based on an image quality feedback ring, an assembling and manufacturing method of a camera module, and a vehicle-mounted camera. The active alignmentmethod comprises the following steps: calculating the image quality of an area involved in active alignment; analyzing a real-time MTF calculation result; judging whether the active alignment parameter is the optimal active alignment parameter or not, and if not, adjusting; and when the image quality of the region involved in active alignment does not meet the preset condition or the MFT calculation result analysis does not meet the preset condition or the active alignment parameter does not meet the preset condition, adopting a hardware communication interface switching module to realize real-time configuration of the parameters of the camera CMOS chip and / or ISP chip for assembly. By applying the technical scheme provided by the invention, the technical problem of poor imaging quality of the camera obtained by adopting the traditional active alignment technology due to difference of LENS, CMOS and ISP types of different cameras in the prior art can be solved.

Description

Technical field[0001]The present invention relates to the field of cameras, in particular to an active alignment method and system based on an image quality feedback loop, a method for manufacturing camera modules, and a vehicle-mounted camera.Background technique[0002]With the rapid development of the Internet of Things and autonomous driving technologies, the application of terminal sensors, especially image sensors, has exploded, and the demand for on-board cameras and wide-angle cameras has increased sharply. At the same time, the application of the camera is not limited to displaying images on the display screen for subjective observation environment, but is more applied to image processing, recognition and other fields, which puts forward higher precision requirements for the clarity and consistency of the camera. Active alignment (Active Alignment, AA) production technology, referred to as active alignment, came into being under this demand. Active alignment technology uses f...

AI Technical Summary

Problems solved by technology

[0003] The current active alignment technology is gradually developing, but due to the LENS, CMOS and ISP matching of different cameras, the image quality of the camera is quite different, and the environment of the active alignment is also different, which has a great impact on the calculation accuracy of the active alignment. The impact of multiple active alignments on the same module often results in differences in the final results of the active alignment due to the above reasons, manifested as significant scaling of the imaging, image displacement, etc., which makes the imaging performance of the final camera consistent. Reduced, thus affecting the successor products for high-precision image processing applications

[0004] In order to improve the quality of active alignment of different camera modules, active alignment equipment suppliers or module manufacturers often need to manually debug in advance for active alignment of different camera products, and the active alignment chart will be adjusted according to the characteristics of the camera. Replace and adjust the on-site lighting environment so that the image quality of the active alignment calculation area can achieve the best active alignment results, which brings new opportunities to the materials of the active alignment chart and the diversity of lighting components. At the same time, higher requirements are put forward for the professionalism of the active alignment equipment debugging personnel, and it often happens that the active alignment equipment debugging personnel repeatedly debug due to the difference in knowledge, and the situation can only be stabilized after multiple trial productions

There are many attempts to this problem in the prior art. For example, patent 201610698589.6 discloses a multi-axis active alignment method for mobile phone camera modules, which measures the best image quality index value according to all preset image local measurement areas. , calculate the deviation between the center of the lens and the center of the image sensor base plate in the X-Y direction; calculate the number of steps of the motor that controls the movement of the lens in the X-Y direction; change the position of the lens along the Z-axis direction, and record the position of the lens and the imaging system after each change. The position is compared to the photos taken by the image detection board; the corresponding lens position when the image quality index of the preset image local measurement area in all the photos is calculated is the best, and the distance between them and the lens position when the image center position obtains the best image quality index is calculated The difference between them; according to the above distance difference, calculate the number of steps of the motor that controls the rotation of the lens when the lens is parallel, and move the motor to correct the tilt of the lens, but for different manufacturers of camera modules or different models of cameras group, it is necessary to replace the special customized active alignment chart card that matches the module. In addition, when the active alignment process and the lighting environment change, the accuracy of the assembled camera module is low

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