Optical Element Light-Shielding Film for Low-Temperature Crack Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical elements with a transparent resin composition on a glass base material suffer from cracking in low temperature environments due to thermal stress, compromising environmental durability while maintaining high quality of appearance.
Innovation Solution
An optical element design incorporating a glass base material with a resin portion and a light-shielding film that has a linear expansion coefficient between the glass and resin, covering part of the side surface and first surface, mitigating thermal stress through a stress mitigating layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a light-shielding film is formed on the edge portion of the lens to improve quality of appearance, then quality of appearance is improved, but cracking of resin occurs in low temperature environment resulting in poor environmental durability
Solution Approach 1:
The patent introduces an intermediate layer between the resin portion and the light-shielding film to mediate the thermal stress. This intermediate layer has thermal expansion characteristics that are intermediate between the resin and the light-shielding film, thereby reducing the stress concentration at the interface and preventing resin cracking in low temperature environments while maintaining the light-shielding function for appearance quality.
Solution Approach 2:
The patent changes the thermal expansion parameter by selecting materials with appropriate linear expansion coefficients. The light-shielding film is chosen to have a linear expansion coefficient between that of the glass base material and the resin portion, creating a gradient that reduces thermal stress during temperature changes and prevents resin cracking while maintaining appearance quality.
2Object-generated harmful factors
If a light-shielding film is formed on the edge portion of the lens, then internal reflection is reduced, but resin cracking occurs in low temperature environment
Solution Approach 1:
The patent introduces an intermediate layer between the resin portion and the light-shielding film to mediate the thermal stress. This intermediate layer has thermal expansion characteristics that are intermediate between the resin and the light-shielding film, thereby reducing the stress concentration at the interface and preventing resin cracking in low temperature environments while maintaining the light-shielding function for appearance quality.
Solution Approach 2:
The patent changes the thermal expansion parameter by selecting materials with appropriate linear expansion coefficients. The light-shielding film is chosen to have a linear expansion coefficient between that of the glass base material and the resin portion, creating a gradient that reduces thermal stress during temperature changes and prevents resin cracking while maintaining appearance 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
The design achieves both excellent quality of appearance and enhanced environmental durability by reducing cracking and bright lines caused by internal reflection, suitable for use in various optical systems.
Implementation Method 1
A linear expansion coefficient of the light-shielding film is between a linear expansion coefficient of the glass base material and a linear expansion coefficient of the resin portion
Data Source
AI summary
An optical element includes a glass base material including a first surface and a second surface opposed to the first surface, a resin portion provided on the first surface, and a light-shielding film configured to cover at least a part of a side surface of the glass base material and a part of the first surface. The second surface is an incident surface or an exit surface for light. A part of the light-shielding film is provided between the glass base material and the resin portion. A linear expansion coefficient of the light-shielding film is between a linear expansion coefficient of the glass base material and a linear expansion coefficient of the resin portion.