Optical Touch Sensor with Camera for Continuous Object Tracking
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Solution Overview
Problem
Existing touch-sensitive devices lose information about touch objects once they leave the surface, limiting tracking capabilities to when the object is in contact with the surface.
Innovation Solution
An optical touch-sensitive device system that uses emitters and detectors around the periphery of a touch surface, combined with a camera, to capture and analyze optical beam disturbances and image data, allowing for continuous tracking of touch objects, including their position, orientation, and type, both during and after contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a camera is added to capture images of touch objects, then tracking capability is improved (objects can be tracked after leaving the surface), but device complexity increases
Solution Approach 1:
The patent combines the camera system with the existing optical beam emitters and detectors to create a unified tracking system. The camera is integrated with the optical infrastructure, allowing image capture and beam disturbance detection to work together through a shared controller, thereby reducing overall system complexity while enhancing tracking capability.
Solution Approach 2:
The optical system serves multiple functions: it detects touch events through beam disturbances and simultaneously captures images of touch objects for tracking after contact. This multi-functionality allows the system to maintain tracking capability without adding completely separate hardware systems, thus managing complexity while improving reliability.
2Measurement precision
If multiple emitters and detectors are used to track touch objects, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The system divides the touch surface into multiple zones covered by different emitter-detector pairs. Each pair monitors specific regions, and the controller processes data from multiple segments to determine precise spatial position. This segmentation allows high measurement precision through coordinated multiple sensors while managing complexity through modular zone-based architecture.
Solution Approach 2:
The controller acts as an intermediary that receives and processes data from multiple emitters and detectors. It integrates information from various beam disturbances to calculate accurate spatial positions, thereby achieving high measurement precision while managing the complexity of coordinating multiple sensors through centralized processing.
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 tracking and identification of touch objects, including styluses, above and on the surface, providing accurate spatial and operational information, and predicting future touch locations, enhancing interaction capabilities.
Implementation Method 1
The emitters produce optical beams that propagate across the touch surface and are received by the detectors
Implementation Method 2
The camera is positioned to capture images of the touch object in contact with the touch surface and/or above the touch surface
Data Source
AI summary
A touch sensitive device includes a touch surface and emitters and detectors. The emitters produce optical beams that propagate across the touch surface and are received by the detectors. Touch events from a touch object disturb the beams propagating toward the detectors. Beam values are recorded by the detectors and used to determine the touch events. The touch sensitive device also includes a camera that captures images of touch objects. The images and variations in the beams are analyzed to continuously track the touch object before, during, and after touch events.