Digital Light Masking for Non-Uniform Opacity Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current automated image inspection systems face challenges with objects of non-uniform opacity, leading to degraded signal-to-noise ratios and low-fidelity lighting compensation due to the limitations of traditional zoned-backlight methods, which are cost-prohibitive and difficult to implement for high-resolution inspections.
Innovation Solution
A digital light masking system using an LCD panel to attenuate uniform source light, allowing for high-resolution, continuously variable lighting compensation, enabling precise control of light transmission and overcoming the limitations of discrete zoning in traditional backlighting systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If discrete zoned-backlight with LED groups is used, then lighting compensation capability is provided, but device complexity and implementation difficulty increase significantly
Solution Approach 1:
The patent introduces a spatial light modulator (SLM) as an intermediary device between the uniform backlight source and the object under inspection. The SLM acts as a programmable mask that can dynamically create different lighting patterns without requiring complex electronic control of multiple LED zones. This mediator enables sophisticated lighting compensation while maintaining simple LED driver electronics.
Solution Approach 2:
The patent creates a digital copy of the desired lighting pattern in the form of a mask image that is displayed on the spatial light modulator. Instead of directly controlling physical LED zones to create complex patterns, the system uses a digital mask that can be easily programmed and modified to generate the required lighting compensation patterns, simplifying the overall system complexity.
2Adaptability or versatility
If discrete zoned-backlight with LED groups is used, then lighting compensation is achieved, but manufacturing precision and resolution are limited
Solution Approach 1:
The spatial light modulator serves as a high-resolution intermediary that can generate fine-grained lighting patterns with much greater precision than discrete LED zones. The SLM's pixel-based structure allows for continuous adjustment of light transmission at each pixel location, enabling high-resolution lighting compensation that would be impossible with coarse LED grouping.
Solution Approach 2:
The patent replaces the mechanical/electronic system of discrete LED zone control with an optical system based on the spatial light modulator. The SLM uses optical modulation at the pixel level to achieve fine resolution lighting patterns, substituting the need for numerous independently controllable LED zones with a single high-resolution modulating surface.
3Ease of manufacture
If uniform backlight is used, then simple and cost-effective implementation is achieved, but imaging quality degrades for objects with non-uniform opacity
Solution Approach 1:
The patent segments the uniform backlight through the spatial light modulator, which divides the light field into individually controllable pixels. This segmentation allows different regions of the backlight to be independently modulated to compensate for non-uniform opacity in the object, while the underlying uniform backlight source remains simple and cost-effective.
Solution Approach 2:
The spatial light modulator introduces dynamic control to the otherwise static uniform backlight. The mask image on the SLM can be dynamically adjusted in real-time to match the specific opacity characteristics of different objects, enabling adaptive compensation without changing the physical backlight source itself.
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 digital light masking system provides high-fidelity imaging with exact lighting compensation, reducing scrap costs and enabling the inspection of complex objects with varying opacity, while being more cost-effective and easier to reproduce than traditional methods.
Implementation Method 1
providing a digital light mask which attenuates the emitted light
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The systems and methods described herein relate to digital light masking systems and methods for automated image inspection. First, a digital light masking system comprising a video signal; a source light which outputs emitted light; a digital light mask which attenuates the emitted light; and a vision system. The systems may inspect a disposable absorbent article. Second, a method for automated image inspection, comprising the steps of: generating a video signal; providing a uniform source light which outputs emitted light; providing a digital light mask which attenuates the emitted light; directing the attenuated light towards an article; and inspecting the article with a vision system. The uniform source light may be an LED light, the digital light mask may be an LCD panel, the attenuated light may be directed towards a disposable absorbent article, and/or the vision system may comprise a camera.