Optical Lens Injection Molding Flow Control for Defect Reduction
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Solution Overview
Problem
Conventional injection molding methods struggle to accurately mold small and thin optical lenses with high optical characteristics due to issues like air incorporation, voids, and weld lines, particularly in the optical function portion, which affects the optical performance.
Innovation Solution
The method involves an injection molding mold design with a convex portion on the flange portion to control the resin flow, ensuring it reaches the optical function portion accurately, and the use of concave portions on the flange to prevent resin from flowing into the flange area, thereby improving the accuracy and optical characteristics of the optical function portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional injection molding method is used, then production efficiency is maintained, but molding precision of optical function portion deteriorates due to air incorporation, voids, and weld lines
Solution Approach 1:
The patent segments the resin flow path into distinct regions by introducing a resin flow control portion that divides the mold cavity. This segmentation ensures that the optical function portion is filled with resin before air can be trapped, preventing voids and weld lines while maintaining production efficiency.
Solution Approach 2:
The patent implements preliminary action by designing the mold to guide resin flow toward the optical function portion first, before other areas are filled. The resin flow control portion creates a flow path that prioritizes filling the optical function portion, ensuring high molding precision before the filling process completes.
2Manufacturing precision
If resin flow is accelerated to fill optical function portion quickly, then molding precision improves, but resin may not properly fill flange portion
Solution Approach 1:
The patent applies local quality by creating different flow control characteristics in different regions of the mold. The resin flow control portion has specific geometric features that locally accelerate resin flow toward the optical function portion while maintaining adequate flow to the flange portion, achieving both high precision and uniform distribution.
Solution Approach 2:
The patent introduces dimensional control through the resin flow control portion's three-dimensional structure. By varying the depth, width, and shape of the flow control features, the patent controls resin flow velocity and distribution in multiple dimensions, ensuring proper filling of both optical function portion and flange portion.
3Ease of manufacture
If gate portion is positioned on flange portion, then ease of manufacture improves, but optical characteristics deteriorate due to defects in optical function portion
Solution Approach 1:
The patent introduces a resin flow control portion as an intermediary element between the gate portion and the optical function portion. This intermediary structure allows the gate to remain positioned on the flange portion for ease of manufacture, while the flow control portion mediates the resin flow to prevent defects in the optical function portion, thus resolving the contradiction.
4Volume of moving object
If thin and small-size optical lens is molded, then miniaturization for mobile devices is achieved, but molding precision deteriorates due to difficulty in controlling resin flow
Solution Approach 1:
The patent applies local quality by designing the resin flow control portion with specific geometric features tailored to the thin lens geometry. The flow control structure creates localized flow patterns that are optimized for filling thin-walled sections, ensuring high molding precision even as the lens is miniaturized for mobile devices.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the precise molding of optical lenses with desired optical characteristics, reducing defects like air incorporation and weld lines, resulting in improved optical performance and image quality in imaging modules.
Implementation Method 1
controlling a fluid state of the resin which flows into the injection molding mold
Data Source
AI summary
The optical lens 10 having an optical function portion 12 having optical functions; and a flange portion 14 formed around the optical function portion 12. The flange portion 14 has, on a side surface thereof, a cut section 42 which is formed by cutting a gate portion 16. In a case where the following are viewed from the optical axis direction of the optical lens 10, a thinnest portion 18 in a region 44 surrounded by lines L1 and L2, which respectively connect both ends 42a and 42b of the cut section 42 to the optical axis center O of the optical lens 10, and a line L3, which connects both ends 42a and 42b, is present in the optical function portion 12. The flange portion 14 has a concave portion 40 outside the region 44.