Wafer Lens Positioning via Segmented Non-Lens Sections
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Solution Overview
Problem
High-resolution image pickup lens units, such as those for cell phone cameras, face challenges in achieving precise positioning of optical systems within holders due to the difficulty in forming surfaces with high accuracy, especially when using wafer lens technology where cut surfaces result in low surface accuracy, making it hard to align the optical axis with the holder's and cover's openings.
Innovation Solution
The image pickup lens unit design includes specific lens and non-lens sections on its surfaces, with a holder and cover featuring contacting and inclining surfaces to align the optical axis accurately, allowing for precise positioning by using the outer circumference surface with a gap and making contact with specific sections of the lens, thereby achieving high positioning accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wafer lens technology is used to produce multiple image pickup lens units simultaneously, then productivity is improved, but manufacturing precision deteriorates because cut surfaces result in low surface accuracy
Solution Approach 1:
The patent divides the lens structure into functional sections: a first lens section for optical function, a first non-lens section for positioning reference, a second lens section, and a second non-lens section. This segmentation allows the non-lens sections to serve as high-precision positioning references even when the lens is cut from a wafer, resolving the contradiction between mass production and positioning accuracy.
Solution Approach 2:
The non-lens sections act as intermediary elements between the cut lens surface and the holder positioning structure. Instead of directly using the low-accuracy cut surface for positioning, the patent introduces non-lens sections that provide stable geometric references (outer circumferences and surfaces) for accurate alignment with the holder and cover openings.
2Ease of operation
If the outer circumference of the lens is used as a reference for positioning in the holder, then the positioning process is simplified, but positioning accuracy deteriorates when surface accuracy is low
Solution Approach 1:
The patent applies local quality by creating specific non-lens sections with distinct geometric properties (outer circumferences and surfaces) that are specifically designed for positioning functions. These localized features provide high-accuracy references without requiring the entire lens surface to have high precision, enabling simple contact-based positioning while maintaining accuracy.
3Device complexity
If the optical system is simultaneously molded with the holder and cover, then device complexity is reduced, but positioning accuracy deteriorates due to difficulty in achieving high accuracy for small components
Solution Approach 1:
The patent incorporates positioning reference features (non-lens sections with specific outer circumferences and surfaces) into the lens structure during the molding or wafer fabrication process, before the positioning operation. This preliminary creation of accurate geometric references enables high-precision alignment to be achieved even in integrated molding processes or when dealing with small components where post-positioning is difficult.
Data Source
AI summary
Image pickup lens unit (100) comprises, in order to minimize the positional displacement between an optical system and a holder therefor, compound lens (6), holder (2) which houses compound lens (6) therein, and cover (4) which covers compound lens (6). In holder (2), there is formed peripheral section (2e) which restricts the movement of compound lens (6) in the XY-direction. In cover (4), there is formed projecting section (4e) which restricts the movement of compound lens (6) in the Z-direction.