Optical Film Defect Detection via Projection and Reflection
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Solution Overview
Problem
Current methods for detecting defects in optical films, such as those used in display units, are inadequate in detecting various shapes of defects like crushed, stabbed, or wrinkled forms, and lack efficiency in expanding the detection region without increasing costs or installation space.
Innovation Solution
A device comprising a light emitting unit, a reflection unit, a screen, and an image capturing unit that projects light onto the optical film, allowing for the expansion of the light irradiation width and enabling the detection of defects by analyzing the projection shape displayed on the screen, which can include a polypropylene screen with reduced surface roughness for clear visualization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional light transmission method is used to detect defects, then the detection process is simple, but the detection region is limited and various shapes of defects cannot be effectively detected
Solution Approach 1:
The patent transitions from direct transmission detection to projection-based detection, changing the dimensional approach of light interaction with the optical film. By projecting light at specific angles and capturing the projection shapes on a screen, the system expands detection capability to various defect shapes (crushed, stabbed, wrinkled) while covering a larger detection region without proportionally increasing system complexity
2Area of stationary object
If the light irradiation width is expanded to widen the detection region, then more defects can be detected, but the light uniformity may be compromised
Solution Approach 1:
The patent employs a reflection unit with specific geometric configuration (including reflection surfaces at defined angles) to locally control and optimize light distribution. This allows the system to expand the detection region while maintaining adequate light uniformity across the projected area, as the reflection geometry is designed to distribute light appropriately across the expanded region
3Area of stationary object
If multiple light sources are used to expand the detection region, then detection coverage increases, but the device complexity and installation cost increase
Solution Approach 1:
The patent introduces a reflection unit as an intermediary component between the light source and the optical film. This single reflection unit effectively multiplies the light coverage area by redirecting light at appropriate angles, achieving expanded detection region coverage without the need for multiple light sources, thereby maintaining simpler system architecture and lower installation costs
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 solution allows for the easy detection of various defects on optical films, including crushed, stabbed, and wrinkled shapes, while reducing installation costs and space, and improving operational efficiency by expanding the detection region without compromising light uniformity.
Implementation Method 1
a reflection unit which reflects the light emitted from the light emitting unit and guides the light to the optical film
Implementation Method 2
a screen which displays a projection shape obtained by projecting the light on the optical film to detect a defect of the optical film
Data Source
AI summary
Provided is a device for detecting a defect of an optical film, comprising a light emitting unit, a reflection unit, a screen, and an image capturing unit, and a method for detecting a defect of an optical film, comprising emitting light to a reflection unit, projecting the light reflected by the reflection unit onto an optical film, capturing an image of a screen which displays a projection shape obtained by projecting the light onto the optical film, and analyzing the image.