TIR Prism Displacement Scale for Roll-to-Roll Web Strain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current displacement measurement technologies for substrates, such as optical encoders, face limitations in accurately determining displacement, particularly in roll-to-roll manufacturing processes, where flexible webs are involved, due to issues with web strain and alignment during multiple deposition steps.
Innovation Solution
The use of total internal reflection (TIR) prism features on a substrate, formed using rollers with TIR features in negative relief, which simultaneously create the displacement scale and pattern features, allowing for precise measurement of translational, rotational, and angular displacements, as well as web parameters like temperature and modulus of elasticity, by modulating light intensity and facilitating alignment across layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional optical encoders are used for displacement measurement on flexible webs, then displacement can be measured, but web strain and alignment issues during multiple deposition steps cause measurement inaccuracy
Solution Approach 1:
The patent replaces traditional mechanical/optical encoder systems with a TIR prism-based optical modulation system. The TIR prisms modulate light intensity based on web position and strain, eliminating the need for complex mechanical encoders that fail under web deformation. This substitution enables accurate displacement measurement even when the flexible web undergoes strain during roll-to-roll processing.
Solution Approach 2:
The patent utilizes changes in light intensity parameters caused by web strain and position to encode displacement information. By monitoring how strain alters the optical path and light intensity at TIR prism features, the system converts physical deformation into measurable optical signal variations, maintaining measurement accuracy despite web strain conditions.
2Adaptability or versatility
If multiple deposition steps are performed on flexible webs, then complex patterns can be created, but alignment accuracy deteriorates due to web strain and movement
Solution Approach 1:
The patent introduces TIR prism features as intermediary reference elements that are deposited simultaneously with each pattern layer. These prisms serve as alignment mediators between layers, providing a common reference framework that compensates for web strain and movement. By using the TIR prisms as intermediaries, the system maintains precise alignment across multiple deposition steps despite flexible web deformation.
Solution Approach 2:
The patent performs preliminary alignment by depositing TIR prism features concurrently with each pattern layer using the same roller. This preliminary action establishes accurate spatial relationships between layers before subsequent processing, ensuring that alignment is locked in early rather than attempted later when web strain may have caused misalignment.
3Productivity
If TIR prism features are formed using rollers with negative relief features, then the displacement scale and pattern features can be formed simultaneously, but the device complexity increases
Solution Approach 1:
The patent merges the formation of the displacement scale (TIR prism features) with the formation of pattern features by integrating both sets of negative relief features onto the same roller. This combining allows simultaneous deposition of both the measurement scale and the functional patterns in a single rolling operation, doubling productivity without requiring separate processing steps.
Solution Approach 2:
The roller is designed with multi-functionality, serving both as a pattern deposition tool and as a scale fabrication tool. The same roller that deposits functional patterns also creates the TIR prism displacement scale, making the device universal for both manufacturing and measurement purposes, thereby eliminating the need for separate equipment.
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 approach provides continuous, accurate tracking of web position and displacement, compensates for web strain, and ensures precise alignment during multi-layer manufacturing, enhancing the efficiency and accuracy of roll-to-roll processes for flexible web substrates.
Implementation Method 1
The scale modulates light directed from the light source by reflecting, transmitting, and/or blocking some of the light. The photosensing element is positioned to sense the modulated light
Data Source
AI summary
Methods and systems for forming a displacement scale comprising TIR prisms on a substrate are described. A system for forming the displacement scale includes one or more rollers having a pattern of total internal reflection (TIR) prism features in negative relief. As the rollers are rotated, the scale is formed on the substrate. The rollers may also include pattern features in negative relief. Rotation of the rollers simultaneously forms the displacement scale and the pattern features on the substrate. The TIR prism features of the displacement scale may be oriented to provide measurement of one or more of lateral displacement, longitudinal displacement and angular displacement.