Foreign Object Detection in Display Coating via Planar Light Scanning
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Solution Overview
Problem
Existing foreign object detecting devices in the display manufacturing industry are inadequate in detecting objects both on and under the substrate, leading to unsatisfactory detection sensitivity and increased risk of nozzle damage due to limited directional detection capabilities.
Innovation Solution
A foreign object detecting device comprising a strip-like light emitting unit and light receiving unit, capable of emitting and detecting light perpendicular to the substrate, which provides brightness distribution and position information of reflective spots, enabling effective detection of foreign objects in both plan and three-dimensional formats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If point-line scanning laser sensor is used to detect foreign objects, then the position of foreign objects can be determined in the coating direction, but the detection sensitivity is insufficient for foreign objects under the substrate and the position in the Y direction cannot be determined
Solution Approach 1:
The patent transitions from one-dimensional point-line scanning detection to two-dimensional planar detection by arranging multiple light emitting units and light receiving units in parallel. This dimensional expansion enables detection of foreign objects both on and under the substrate surface, and determines positions in both X and Y directions simultaneously, resolving the limitation of the conventional single-direction scanning method
2Reliability
If laser transmitter and receiver are arranged in front of nozzle in coating direction, then foreign objects on substrate can be detected, but foreign objects under substrate cannot be effectively detected leading to nozzle collision damage
Solution Approach 1:
By expanding from single-direction detection to multi-directional planar detection with parallel arranged light units, the system can detect foreign objects at different depths and positions, including those under the substrate that would cause nozzle damage, thereby eliminating the harmful effect of undetected foreign objects
Solution Approach 2:
The detection device performs comprehensive planar scanning of the substrate surface before the coating process, identifying and flagging foreign objects in advance. This preliminary detection prevents subsequent nozzle collisions and damage, allowing for preventive action before the harmful effect occurs
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 accurate detection of foreign objects on and under the substrate, preventing nozzle collisions and improving detection efficiency by providing detailed positional and dimensional information, thus enhancing the coating process.
Implementation Method 1
the light receiving unit is used for detecting an optical signal of reflected light reflected from the surface of the substrate to be detected
Data Source
AI summary
The present disclosure provides a foreign object detecting device and a coating system. The foreign object detecting device includes a light emitting unit and a light receiving unit arranged side by side, the light emitting unit is used for emitting light towards a surface of a substrate to be detected, and the light receiving unit is used for detecting an optical signal of reflected light reflected from the surface of the substrate to be detected and capable of outputting the detected optical signal, and the optical signal includes brightness distribution information of the reflected light and position information of reflective spot. In the present disclosure, the foreign object is detected by emitting light towards the substrate and detecting change in brightness of the reflected light.