Calibrating Apparatus for Optical Touch Screen Sensor Alignment
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Solution Overview
Problem
The precision of touch point detection in optical touch screens is severely affected by improper installation of light sensors, leading to erroneous judgments, as existing technologies lack effective calibration methods for adjusting the position and angle of these sensors.
Innovation Solution
A calibrating apparatus and method that utilize known indicating points and reference points on a panel to determine calibration points and generate calibration functions, allowing for precise adjustment of light sensor positions and angles, thereby improving touch point detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light sensor position and angle are not precisely calibrated, then the device complexity is reduced (no calibration system needed), but the measurement precision of touch point detection deteriorates severely
Solution Approach 1:
The calibration apparatus performs position and angle calibration of light sensors before actual touch detection operations. By pre-adjusting the sensors to correct positions and angles using indicating points and reference points, the system ensures high measurement precision without requiring complex real-time correction mechanisms during normal operation.
Solution Approach 2:
The calibration apparatus introduces indicating points and reference points as intermediary elements to facilitate the calibration process. These markers serve as mediators between the light sensor and the touch screen, enabling precise position and angle adjustment through geometric relationships without requiring direct complex measurements of the sensor itself.
2Reliability
If light sensor installation position and angle are not accurate, then the ease of manufacture is improved (simpler installation process), but the reliability of touch point detection deteriorates due to erroneous judgments
Solution Approach 1:
The calibration apparatus enables the light sensor to self-calibrate its position and angle by using geometric relationships between indicating points, reference points, and the sensor's field of view. The system automatically determines the correct installation parameters through mathematical calculations based on captured images of known reference points, eliminating the need for manual precision adjustment during manufacturing.
Solution Approach 2:
The patent replaces mechanical precision adjustment mechanisms with a computational calibration approach. Instead of relying on precise mechanical installation of light sensors, the system uses image processing and geometric calculations to determine and correct position and angle deviations, substituting mechanical precision requirements with software-based calibration.
3Measurement precision
If multiple indicating points and reference points are used for calibration, then the measurement precision is improved, but the loss of time increases due to the calibration process
Solution Approach 1:
The calibration process is segmented into distinct phases: position calibration using indicating points, angle calibration using reference points, and validation phases. This segmentation allows the system to use different sets of points for different calibration objectives, improving overall precision while managing time consumption by focusing on critical calibration parameters in separate steps.
Solution Approach 2:
The calibration apparatus changes geometric parameters (positions of indicating points, angles of reference lines) to optimize the calibration process. By strategically selecting and positioning multiple indicating and reference points at specific locations on the touch screen, the system maximizes calibration precision while minimizing the number of points required, thus reducing calibration time.
Data Source
AI summary
A calibrating apparatus for an image processing apparatus is disclosed. The calibrating apparatus comprises a first operating module and a second operating module. The first operating module determines a third indicating point and a fourth indicating point according to a first indicating point, a second indicating point, and a specific point, and determines a calibration point (i.e. the predetermined position of a sensor) according to a first line through the first indicating point and third indicating point and a second line through the second indicating point and fourth indicating point. The second operating module forms reference lines according to reference points and the calibration point, forms reference angles according to the reference lines and a parallel line, generates reference coordinates of the reference points in an image and generates a calibration function according to the reference coordinates of the reference points and the reference angles.