Lens Defect Detection Using Moiré Pattern Distortion
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Solution Overview
Problem
The existing methods for evaluating lenses in communication devices, such as cellular phones, are inefficient as they do not effectively detect optic defects until the lens is installed and the LCD is activated, leading to potential distortions and manufacturing inefficiencies.
Innovation Solution
A system and method using a substrate with a pattern of lines or geometric shapes to visually identify defects in lenses by observing moiré distortions when viewed through the lens, allowing for pre-installation evaluation and rejection of defective lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a lens is made clear and transparent to provide good visual interface, then the display appearance is improved, but it becomes difficult to detect optic defects until installation
Solution Approach 1:
A test substrate with grid pattern is introduced as an intermediary between the lens and the observer. This substrate enables defect detection by creating visible moire patterns when viewed through the lens, solving the problem of detecting defects in otherwise clear transparent lenses without compromising their visual clarity.
Solution Approach 2:
The test substrate uses high-contrast black and white grid patterns that produce moire interference patterns when viewed through defective lenses. These optical interference effects create visible distortions and color variations that reveal defects in the lens that would otherwise be invisible.
2Measurement precision
If lens evaluation is performed after installation to ensure quality, then defect detection accuracy is improved, but manufacturing efficiency deteriorates
Solution Approach 1:
Lens evaluation is performed before installation by placing the lens over the test substrate with grid pattern. This preliminary action allows defects to be detected and lenses to be rejected prior to assembly, improving manufacturing efficiency by preventing defective lenses from being installed while maintaining accurate defect detection through the moire pattern method.
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
Enables the identification of defective lenses prior to installation, ensuring only distortion-free lenses are used, thereby improving manufacturing efficiency and preventing visual distortions in LCD displays.
Implementation Method 1
The pattern comprises a series of lines in a grid imposed on the substrate wherein when the pattern is viewed through the lens, the series of lines having thickness of between approximately 10 and approximately 150 microns, spaced in intervals between approximately 20 microns and approximately 300 microns from center to center, the pattern is distorted around an area where a defect is present in the lens. With the device, the lens is identifiable as being defective if the pattern appears as a moiré distortion in the area when viewed through the lens.
Data Source
AI summary
The disclosure relates to a system and device for evaluating imperfections in a lens for a display for an electronic device. The evaluation device comprises: a substrate; and a pattern imposed on the substrate. The pattern comprises a series of lines in a grid imposed on the substrate wherein when the pattern is viewed through the lens, the series of lines having thickness of between approximately 10 and approximately 150 microns, spaced in intervals between approximately 20 microns and approximately 300 microns from center to center, the pattern is distorted around an area where a defect is present in the lens. With the device, the lens is identifiable as being defective if the pattern appears as a moiré distortion in the area when viewed through the lens.