Long Lens Curved Draft Surface Reduces Injection Volume
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Solution Overview
Problem
Existing lens manufacturing processes require longer times due to increased volume caused by flatly shaped draft surfaces, leading to extended injection, cooling, and mold removal times.
Innovation Solution
A lens design featuring a lens portion with curved oblong surfaces, rib portions, and a draft surface with a slant surface that curves inwardly and increases gradually toward the rib portion, reducing volume and manufacturing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If flatly shaped draft surfaces are provided at the oblong sides of the lens portion, then the lens can be smoothly removed from the mold, but the volume of the lens increases due to added triangular prismatic portions
Solution Approach 1:
The draft surface is designed with a curved slant surface that curves inwardly with a draft increasing gradually toward the rib portion, rather than using flat triangular prismatic portions. This curvature reduces the volume added by the draft surface while maintaining smooth mold removal capability.
2Ease of manufacture
If the volume of the lens is increased by adding triangular prismatic portions for draft surfaces, then the lens can be removed from the mold, but the manufacturing time increases due to longer injection and cooling periods
Solution Approach 1:
The curved slant surface of the draft surface reduces the volume of material that needs to be injected and cooled, thereby shortening the injection and cooling periods while still enabling smooth mold removal.
Solution Approach 2:
The draft angle is varied along the slant surface, increasing gradually toward the rib portion. This parameter change optimizes the balance between mold removal smoothness and volume reduction, achieving faster manufacturing without sacrificing ease of demolding.
3Device complexity
If flatly shaped draft surfaces with triangular prismatic portions are used, then the lens structure is simple, but the weight of the lens increases
Solution Approach 1:
The curved slant surface reduces the overall volume of the draft surface compared to flat triangular portions, thereby reducing the lens weight while maintaining structural simplicity and smooth mold removal.
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
The design reduces manufacturing time, decreases mold releasing resistance, and results in a lighter, easier-to-manufacture lens with reduced weight and minimized interstices between mold components.
Implementation Method 1
a curved lens surface having a refractive power
Data Source
AI summary
A lens including a lens portion having first and second opposite oblong surfaces is disclosed. At least one of the first and second oblong surfaces of the lens portion is a curved lens surface having a reflective power. A rib portion is disposed at each of two opposite sides of the lens portion facing in a direction of a width of the first oblong surface. The rib portion extends along a longitudinal direction of the lens portion in a position separate from the second oblong surface. A draft surface extends between the second oblong surface and the rib portion. The draft surface includes a slant surface slanting outwardly toward the rib portion. The slant surface is curved inwardly with a draft thereof increasing gradually toward the rib portion.