Optical Touch Surface with Tactile Features for Scalable Detection
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Solution Overview
Problem
Existing touch-sensitive technologies face challenges in scaling to larger screen sizes, handling multitouch events efficiently, and meeting increasing resolution demands, often resulting in high costs and low yields.
Innovation Solution
An optical touch-sensitive device featuring a planar optical waveguide structure with tactile surface features and emitters/detectors arranged along the periphery, utilizing total internal reflection to detect touch events, which scales linearly with screen size and effectively handles multitouch events by analyzing transmission coefficients to determine touch locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If traditional touch-sensitive technologies are used, then they function well for small sized displays, but they do not scale well to larger screen sizes
Solution Approach 1:
The system segments the touch detection function into distributed emitters and detectors arranged along the periphery, with optical beams serving as the connecting medium. This segmentation allows the system to scale to larger screens without proportionally increasing processing complexity, as each emitter-detector pair operates independently to define a beam that can be disrupted by touch events anywhere along its path.
Solution Approach 2:
The patent transitions from planar or surface-based touch detection to a three-dimensional optical space approach. By arranging emitters and detectors along the periphery and using optical beams that propagate through the volume above the display surface, the system gains an additional dimensional space for touch detection, enabling scalable implementation across various screen sizes.
2Length of stationary object
If technologies requiring specially processed surfaces or special elements are used, then they can detect touch events, but increasing screen size by N means N2 times as many special elements are required
Solution Approach 1:
The optical beams serve multiple functions simultaneously: they carry touch detection information, provide the detection mechanism itself, and enable the system to scale linearly rather than quadratically. By using light as a universal carrier that can span the entire display area without requiring proportional increases in processing elements, the system achieves efficient scaling to larger screens.
3Adaptability or versatility
If traditional touch technologies are used, then they can handle touch events, but they have difficulty in handling multitouch events efficiently
Solution Approach 1:
The patent replaces complex computational touch event resolution with optical physics-based detection. Instead of using computationally intensive algorithms to resolve ambiguities in electrical signals from multiple touch points, the system uses optical beams whose disruption patterns naturally encode touch location information, allowing multitouch events to be detected and resolved through optical measurement rather than computational solving.
4Measurement precision
If traditional touch technologies are used, then they can provide basic touch detection, but they cannot meet increasing resolution demands
Solution Approach 1:
The system achieves high resolution touch detection by changing optical parameters such as beam wavelength, intensity, and angle rather than increasing the number of discrete sensors. By measuring subtle changes in optical beam properties caused by touch events, the system can achieve fine resolution without proportionally increasing system complexity, as a single optical beam can provide continuous spatial information along its entire path.
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
The solution enables efficient and cost-effective touch detection on larger screens with improved multitouch capabilities and resolution, providing a scalable and computationally efficient method for touch-sensitive systems.
Implementation Method 1
The emitters produce optical beams that propagate through the waveguide structure via total internal reflection (TIR) to the detectors.
Data Source
AI summary
An optical touch-sensitive device includes a top surface that includes tactile surface features. This produces a tactile effect experienced by the user using a finger or object (e.g., pen, stylus, or other instrument) on the surface.