Optical Touch Stylus Positioning via Brightness Threshold Segmentation
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Solution Overview
Problem
Optical touch systems face inaccuracies in determining the position of an optical touch stylus due to the generation of mirror images on the touch surface, leading to inconvenient usage and disconnection issues.
Innovation Solution
An optical touch apparatus and method that utilize an optical sensor and touch controller to sense a light beam from an optical touch stylus, calculate a brightness threshold, and distinguish between the stylus's reflection image and its mirror image on the touch surface, allowing for accurate determination of the stylus's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical touch stylus is used to perform touch operations on the touch surface, then the touch system can detect touch operations through light signals, but the optical touch stylus generates a mirror image on the touch surface which causes inaccurate position determination
Solution Approach 1:
The patent segments the sensing data by calculating a brightness threshold to separate the mirror image data from the actual touch stylus data. The touch controller divides the sensing data into first data (actual touch position) and second data (mirror image) based on brightness comparison, enabling accurate position determination by selecting only the relevant first data.
Solution Approach 2:
The patent converts the harmful mirror image effect into a useful reference by comparing the brightness of sensing data with the calculated brightness threshold. The mirror image, initially a source of error, becomes a means to establish the brightness threshold that helps distinguish actual touch positions from false readings.
2Reliability
If the determined position of the stylus tip is too low, then touch response is generated prematurely, but if the determined position is too high, then the connection of the stylus on the touch surface is disconnected
Solution Approach 1:
The patent implements feedback by using the brightness threshold as a reference to continuously adjust and determine the accurate position of the touch indicator point. The touch controller compares sensing data against the brightness threshold to provide feedback on the actual touch position, ensuring reliable touch operation without premature response or disconnection.
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 enhances the accuracy of determining the touch indicator point's position, reducing errors and improving the usability of the touch system by correctly identifying the stylus's position on the touch surface.
Implementation Method 1
an optical touch stylus capable of reflecting or emitting a light beam
Implementation Method 2
a mirror image generated by the optical touch stylus on the touch operation surface
Data Source
AI summary
An optical touch apparatus configured to sense a touch operation of an optical touch stylus is provided. The optical touch apparatus includes a touch operation surface, an optical sensor and a touch controller. The optical touch stylus performs the touch operation on the touch operation surface. The optical sensor is disposed on a side of the touch operation surface and senses the light beam from the touch operation to obtain sensing data. The sensing data include an image of the optical touch stylus and a mirror image generated on the touch operation surface by the optical touch stylus. The touch controller is electrically connected to the optical sensor and calculates a brightness threshold according to the sensing data. The touch controller determines a position of the touch indicator point of the optical touch stylus on the touch operation surface according to the sensing data and the brightness threshold.