Laser Sensor for Liquid Droplet Shape Measurement in Display Manufacturing
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Solution Overview
Problem
Existing display device manufacturing methods face challenges in accurately controlling the discharge of liquid droplets onto substrates, particularly in determining the planar shape and center of droplets, which affects the precision and quality of the display device manufacturing process.
Innovation Solution
An apparatus and method that utilize a sensor unit emitting a laser to irradiate and measure the planar shape of liquid droplets falling onto a substrate, adjusting the operation of the head unit based on the sensed shape to ensure accurate discharge, including the use of a reflector to bend the laser path and multiple sensors for precise measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser sensor is used to measure the planar shape of liquid droplets, then measurement precision is improved, but device complexity increases
Solution Approach 1:
A reflector is introduced as an intermediary component to bend the laser path and enable the sensor to measure the droplet's planar shape from a remote position. The reflector redirects the laser beam to illuminate the droplet and guide the reflected light back to the sensor, allowing precise measurement without requiring the sensor to be in direct contact with or extremely close to the droplet, thus managing device complexity while maintaining measurement precision.
Solution Approach 2:
The measurement system transitions from direct linear measurement to multi-dimensional optical path measurement. By using a reflector to bend the laser path in three-dimensional space, the system can measure the droplet's planar shape (x, y coordinates) from a distance, adding spatial dimensionality to the measurement approach and reducing the need for complex close-proximity sensor arrangements.
2Measurement precision
If multiple sensors are used to measure the liquid droplet, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The sensor unit is segmented into multiple independent laser sensors arranged in a line, each capable of measuring specific portions of the droplet's planar shape. This segmentation allows the system to capture comprehensive shape information by combining measurements from multiple sensors, improving overall measurement precision while maintaining manageable device complexity through modular sensor design.
Solution Approach 2:
Multiple sensors in the array serve universal functions of measuring different segments of the droplet's planar shape. Each sensor can independently detect the droplet's position and shape characteristics, and collectively they provide complete shape information, making the sensor array versatile for various measurement scenarios without requiring specialized single-purpose components.
3Manufacturing precision
If real-time monitoring of liquid droplet discharge is implemented, then manufacturing precision is improved, but productivity decreases
Solution Approach 1:
The laser sensor performs preliminary measurement of the liquid droplet's planar shape and position before the droplet is fully discharged onto the substrate. This preliminary action allows the system to verify droplet formation and positioning in real-time, enabling immediate correction if necessary, thus improving manufacturing precision without significantly delaying the overall discharge process and maintaining productivity.
Solution Approach 2:
The sensor unit provides real-time feedback on the droplet's planar shape and position during discharge. This feedback mechanism allows the manufacturing system to continuously monitor and adjust droplet discharge parameters, ensuring high precision while maintaining efficient production rates through rapid measurement and correction cycles that minimize process interruption.
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 real-time monitoring and control of liquid droplet discharge, ensuring accurate placement and uniformity, thereby improving the quality and precision of display device manufacturing.
Implementation Method 1
the laser is reflected by the liquid droplet arranged in a region apart from the sensor unit by a first distance to generate reflected light and the sensor unit determines the portion of the planar shape using the reflected light
Data Source
AI summary
An apparatus for manufacturing a display device includes: a stage configured to hold a substrate; a movement unit configured to move relative to the stage; a head unit arranged on the movement unit and including a nozzle for discharging a liquid droplet onto the substrate; and a sensor unit configured to emit a laser to irradiate the liquid droplet falling from the head unit to the substrate to sense a portion of a planar shape of the liquid droplet. The apparatus is configured to control the movement unit or the head unit based on the sensed portion of the planar shape.