3D Printer Inkjet Detection via Shaft Reflection
Solution Overview
Problem
Three-dimensional printers face issues with inconsistent functionality of inkjets, leading to volumetric differences that can result in incomplete or defective prints, requiring costly and time-consuming scrapping of objects due to inoperative inkjets during the lengthy printing process.
Innovation Solution
A three-dimensional object printer system equipped with a shaft, light source, and light sensor, controlled by a controller to detect inoperative inkjets by comparing material height signals generated by the sensor to expected values, allowing for real-time identification and potential compensation during the printing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional printing processes are used without detection systems, then the printing process can proceed without additional equipment, but inoperative inkjets cannot be identified and lead to defective prints requiring scrapping
Solution Approach 1:
A light source and light sensor are introduced as intermediary components to detect material height on the shaft. The light source illuminates the material and the light sensor measures the reflected light to determine height, enabling indirect measurement of inkjet functionality without directly contacting or complicating the printing mechanism
Solution Approach 2:
The mechanical detection approach is replaced with an optical detection system. Instead of using mechanical probes to measure material height, the patent uses light sources and light sensors to optically measure the height of material deposited by inkjets, reducing mechanical complexity and improving measurement precision
2Loss of time
If inoperative inkjets are not detected during printing, then the printing process continues uninterrupted, but volumetric differences accumulate and result in scrapped objects after hours or days of printing
Solution Approach 1:
The system performs preliminary detection of inkjet functionality by measuring material height on the shaft during or after deposition, before the printing process completes. This allows early identification of inoperative inkjets and prevents accumulation of volumetric differences that would otherwise lead to scrapped objects after hours or days of printing
Solution Approach 2:
The light sensor provides feedback about material height to the controller, which compares measured heights to expected values. This feedback loop enables real-time or near-real-time detection of inoperative inkjets, allowing for timely intervention before printing defects accumulate to scrappable levels
3Manufacturing precision
If inoperative inkjets are not detected, then no additional detection equipment is needed, but surface variations become significant enough to require scrapping of the object
Solution Approach 1:
The light source and light sensor serve as intermediary measurement tools that enable precision detection of surface variations without directly interfering with the printing process. The optical measurement system captures height information at multiple positions on the shaft, enabling detection of surface uniformity issues
Solution Approach 2:
The system measures material height in the vertical dimension by detecting light reflection patterns. By measuring at multiple angular positions as the shaft rotates, the system captures three-dimensional surface information, enabling detection of surface uniformity and volumetric differences that would affect print quality
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 detection and potential compensation for inoperative inkjets, reducing the likelihood of defective prints and minimizing the need for scrapping, thereby saving time and resources.
Implementation Method 1
at least one light source, at least one light sensor... enable the at least one sensor to generate signals indicative of a height of material at a plurality of positions on the shaft
Data Source
AI summary
A three dimensional printer is configured to move at least one printhead from an area where the printhead is forming an object to a position opposite a shaft. The at least one printhead is operated to eject material onto the shaft and the shaft is rotated to enable a light sensor to generate signals indicative of a height of material at a plurality of positions on the shaft. The signals are compared to an expected height of material at each position to identify inoperative inkjets in the at least one printhead.