Method and system for a single frame camera module active alignment tilt correction

Abstract

Some embodiments include methods for correcting optical alignment of components in a camera module for a multifunction device. In some embodiments, components of a camera module for use in a multifunction device are assembled on a test station. Some embodiments include a method that includes capturing a single test image, calculating from the spatial frequency response data an optical tilt between the optical axis of a lens and an optical axis of the image sensor of the camera module, and mechanically adjusting an alignment of the lens and the optical axis of the image sensor of the camera module to reduce the optical tilt. In some embodiments, the capturing is performed using the components of the camera module, and the single test image contains visually encoded spatial frequency response data for characterizing the components of the camera module.

Description

BACKGROUND[0001]1. Technical Field[0002]This disclosure relates generally to camera module components and more specifically to adjusting the optical alignment of camera components.[0003]2. Description of the Related Art[0004]The advent of small, mobile multipurpose devices such as smartphones and tablet or pad devices has resulted in a need for the mass production of high-resolution, small form factor cameras, capable of generating high levels of image quality, for integration in the devices. Mass production creates pressure to maximize throughput of the machines used for assembling these cameras.[0005]Camera module active alignment is thought of in terms of an image quality driven process that aligns a camera module lens to the image sensor, taking into consideration the optical properties of the combined lens / sensor system rather than only considering the mechanical alignment in physically assembling and bonding these two components together, as typically done in a high-throughput...

AI Technical Summary

Benefits of technology

[0007]Some embodiments include methods for correcting optical alignment of components in a camera module for a multifunction device. In some embodiments, components of a camera module for use in a multifunction device are assembled on a test station. Some embodiments include a method that includes capturing a single test image, calculating from spatial frequency response data derived from the test image an optical tilt between the optical axis of a lens and an optical axis of the image sensor of the camera module, and mechanically adjusting an alignment of the lens and the optical axis of the image sensor of the camera module to reduce the optical tilt. In some embodiments, the capturing is performed using the components of the camera module, and the single test image contains visually encoded spatial frequency response data for characterizing the components of the camera module.

Problems solved by technology

While camera modules active alignment is a key process in assembling a high resolution compact camera with high levels of image quality, conventional active alignment methods have low throughput compared with the conventional mechanical alignment process, making it difficult and expensive to meet mass production demands.

Manufacturing tolerances of the lens elements placed into the lens barrel, as well as tolerances in component placement, result in tilt and decenter between the lens and sensor, which can degrade image quality in the finished camera, especially on the periphery of images taken by the camera, which may exhibit noticeable blur at the edges and sharpness at the center.

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