Vehicular Camera Dual Focusing for Six-DOF Optical Alignment
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Solution Overview
Problem
Current vehicle vision systems face challenges in managing camera component tolerances and manufacturing focus/alignment processes, leading to expensive and complex solutions that do not fully compensate for all degrees of freedom in lens and imager alignment.
Innovation Solution
A vehicle vision system that uses a camera assembly process with a lens barrel and imager printed circuit board, where the lens barrel is threaded into a lens holder with a biasing element to compensate for thread looseness, and adhesive bonding allows for fine adjustments and optical alignment, enabling compensation for six degrees of freedom (X, Y, Z, U, V, W) and post-assembly fine tuning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional camera assembly methods are used with fixed lens and imager positioning, then manufacturing is simpler, but alignment precision and focus accuracy deteriorate due to tolerance accumulation
Solution Approach 1:
The patent implements a dynamic adjustment mechanism where the lens barrel can be rotated to adjust the focus of the lens relative to the imager after assembly. This dynamic feature allows for post-assembly fine-tuning of the optical alignment, compensating for manufacturing tolerances without requiring extremely precise initial positioning. The adjustable focus mechanism transforms a static assembly into a dynamically可调 system, resolving the contradiction between manufacturing simplicity and alignment precision.
2Manufacturing precision
If tight tolerances are specified for lens and imager components, then alignment accuracy improves, but manufacturing cost and complexity increase
Solution Approach 1:
The patent employs a two-stage assembly approach: first, rough positioning of the lens barrel relative to the imager is performed during initial assembly, and second, fine adjustment is made by rotating the lens barrel after assembly. This preliminary action followed by adjustment allows standard manufacturing tolerances to be used while achieving high final alignment accuracy, eliminating the need for expensive tight-tolerance components or complex pre-alignment procedures.
Solution Approach 2:
The patent changes the focus parameter by rotating the lens barrel, which alters the distance between the lens and imager. This parameter adjustment allows the system to compensate for manufacturing variations in lens and imager positioning, achieving accurate focus without requiring precise initial manufacturing tolerances. The ability to vary the optical path length provides a degree of freedom that simplifies manufacturing while maintaining precision.
3Ease of manufacture
If threaded connection is used to attach lens barrel, then assembly is easier, but thread looseness causes focus instability
Solution Approach 1:
The patent designs the lens barrel with both threaded connection for initial attachment and rotational adjustment capability for focus tuning. The threaded connection provides easy assembly, while the subsequent rotational adjustment allows for fine-tuning and stabilization of the focus position. This dynamic two-stage process ensures that the ease of threaded assembly does not compromise focus stability, as the final position can be precisely set and locked.
Data Source
AI summary
A vehicular camera includes (i) a lens barrel accommodating a lens, (ii) a lens holder having a passageway and (iii) an imager printed circuit board attached to the lens holder with the imager facing the lens. The lens barrel at least partially passes through the passageway of the lens holder when attaching the lens barrel to the lens holder. The imager printed circuit board is attached to the lens holder with the imager facing the lens and optically aligned with the lens. A biasing element urges the lens barrel in a direction outward away from the imager printed circuit board. With the imager printed circuit board attached to the lens holder, the lens barrel is fine adjustable relative to the lens holder. A rear housing attached at the lens holder to encase the imager printed circuit board.