Resin Optical Prism Molding to Reduce Gate Mark Strain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing resin optical prisms using injection molding result in temperature distribution and internal strain due to thermal conductivity differences between resin and mold materials, leading to uneven density and refractive index distribution, which adversely affect optical characteristics.
Innovation Solution
The method involves two-stage injection molding, where a first molded part is formed and then covered by a second molded part, with the first gate mark being covered by the second molded resin to reduce internal stress through annealing, thereby improving optical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If injection molding is used to manufacture thick resin optical prisms, then the prism shape and optical functions are achieved, but temperature distribution and internal strain occur due to thermal conductivity differences between resin and mold, leading to uneven density and refractive index distribution
Solution Approach 1:
The thick prism is divided into two separate molded parts: a first molded part forming the core structure and a second molded part forming the outer layer. This segmentation allows each part to be molded with reduced thickness, minimizing temperature distribution and internal strain while achieving the required thick prism shape and optical functions.
2Ease of manufacture
If the first molded part is molded using the first mold, then the base structure is formed, but internal strain easily occurs around the gate mark portion, which adversely affects optical characteristics if the strain remains in the optical path
Solution Approach 1:
The second molded part acts as an intermediary layer that covers and protects the gate mark portion of the first molded part. By positioning the gate mark in a recess and covering it with the second resin part, the harmful internal strain around the gate mark is isolated from the optical path, allowing the first molded part to be manufactured with standard molding processes while maintaining optical quality.
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 significantly reduces internal strain and enhances optical performance by minimizing residual stress and improving surface accuracy of the optical surfaces.
Implementation Method 1
the first gate mark being covered by the second molded resin to reduce internal stress through annealing
Data Source
AI summary
An optical element includes a first molded part made of resin and a second molded part made of resin and configured to cover at least a part of the first molded part. The first molded part has a recess. The second molded part has a first resin part having an optical surface on an outer surface and a second resin part having a non-optical surface on an outer surface. A gate mark in molding the first molded part is disposed in the recess and covered with the second resin part.