Coating Apparatus Droplet Volume Correction via Side-View Imaging
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Solution Overview
Problem
Existing methods for correcting the ejection amount of liquid materials are hindered by instability in measurement due to fluctuations in the liquid surface and apparatus vibrations, and inaccuracies in calculating droplet volume from overhead camera images, which fail to correctly measure and adjust the ejection amount.
Innovation Solution
A method involving a mirror set at a predetermined angle relative to the application target surface to capture images of droplets in a direction parallel to the surface, allowing for accurate calculation of droplet volume and correction of ejection amount, potentially using multiple mirrors or a rotating stage for enhanced measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the liquid material is received on a saucer for weight measurement, then the ejection amount can be measured, but the measured value is not stabilized until fluctuations of the liquid surface is settled, causing a relatively long measurement time
Solution Approach 1:
The patent replaces the mechanical weight measurement system with an optical imaging and image analysis system. Instead of using a scale that requires liquid surface stabilization, the invention captures images of the droplet and calculates volume from the image data, eliminating the need for mechanical measurement and its associated stabilization time.
Solution Approach 2:
The patent introduces a mirror as an intermediary element to enable side-view imaging of the droplet. The mirror reflects the droplet image from a different angle, allowing the imaging system to capture droplet shape information without being affected by liquid surface fluctuations that plague direct weight measurement methods.
2Measurement precision
If a camera is used to pick up an image of a droplet from above, then the ejection amount can be measured, but the height of the droplet cannot be recognized and the amount of the droplet cannot be correctly calculated
Solution Approach 1:
The patent transitions from top-down imaging to side-view imaging by positioning the camera to capture the droplet from a lateral perspective. This dimensional change allows the imaging system to capture droplet height information, which is essential for accurate volume calculation, while maintaining relatively simple device configuration through the use of a mirror.
3Productivity
If the ejection is performed for a long time, then continuous application can be achieved, but the liquid material causes a time-dependent change in viscosity and the ejection amount varies
Solution Approach 1:
The patent implements a feedback mechanism where the measured droplet volume from image analysis is used to adjust and correct the ejection amount. This closed-loop control system continuously monitors the actual ejection amount and makes real-time adjustments to compensate for viscosity changes, maintaining consistent ejection precision during continuous operation.
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 precise measurement and correction of ejection amounts, reducing variability and ensuring consistent application, even with changes in viscosity over time.
Implementation Method 1
a mirror is set near an application target surface at a predetermined angle with respect to the application target surface, an image of a droplet formed on the application target surface is picked up in the direction parallel to the application target surface through the mirror
Data Source
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AI summary
Provided is an ejection amount correction method and an applying apparatus, which can correctly measure the amount of an applied droplet and accurately correct the ejection amount. In an ejection amount correction method for measuring the amount of a liquid material ejected from a nozzle and correcting the ejection amount of the liquid material, a mirror is set near an application target surface at a predetermined angle with respect to the application target surface, an image of a droplet formed on the application target surface is picked up from a side through the mirror, the volume of the droplet is calculated based on the picked-up image of the droplet, and the ejection amount is corrected based on the calculated volume. An apparatus for carrying out the method is also provided.