Projection System Self-Calibration via Optical Path Distance Calculation
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Solution Overview
Problem
Existing projection systems with separate projector and mirror units face challenges in calibration due to unknown distances between components, requiring labor-intensive manual measurements and potentially low precision.
Innovation Solution
A projection system comprising a projector, omnidirectional camera, and control PC that calculates and adjusts distances and angles automatically using captured images, allowing for easy calibration without dedicated measurement sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate projector and mirror units are used to provide flexibility in installation, then adaptability is improved, but calibration complexity increases due to unknown distances between components
Solution Approach 1:
The system performs self-calibration by automatically calculating distances between the projector and mirror, and between the mirror and projection surface, using image capture and processing functions. The controller computes calibration parameters without requiring external measurement tools or manual intervention, enabling the system to calibrate itself based on captured images of the projection surface.
2Measurement precision
If manual measurement methods are used for calibration, then measurement precision can be maintained, but time consumption increases significantly
Solution Approach 1:
The patent replaces manual mechanical measurement methods with an automated optical measurement system. The capture unit takes images of the projection surface, and the controller processes these images to automatically calculate distances and calibration parameters, substituting human-operated mechanical measuring tools with an automated vision-based system that achieves both precision and speed.
Solution Approach 2:
The system creates a digital copy of the projection surface by capturing its image, then uses this image copy to calculate calibration parameters. Instead of physically measuring the setup, the system works with a digital representation (the captured image) to derive all necessary calibration data, significantly reducing time while maintaining precision.
3Measurement precision
If dedicated measurement sensors are added to the system, then measurement precision improves, but device complexity and cost increase
Solution Approach 1:
The capture unit, which is already part of the system for other purposes, is utilized for distance measurement during calibration. The same hardware component performs multiple functions: capturing projection content and simultaneously providing measurement data for calibration. This eliminates the need for dedicated measurement sensors while maintaining measurement precision.
Solution Approach 2:
The system uses its own existing capture unit to perform measurement functions that would otherwise require separate dedicated sensors. By making the capture unit serve dual purposes (content capture and distance measurement), the system achieves self-sufficiency and avoids adding extra hardware components.
Data Source
AI summary
A projection system includes a projection unit, an optical path change unit, a capture unit, and a controller. The projection unit emits projection light for displaying an image. The optical path change unit changes an optical path for the projection light and guides the projection light toward a prescribed projection surface. The capture unit captures a projection image that is projected onto the projection surface from the optical path change unit, based on the image. The controller calculates a first distance that is a length from the projection unit to the optical path change unit along the optical path and a second distance that is a length from the projection unit to the projection surface along a vertical direction, based on the captured image by the capture unit, and controls the projection image based on the first distance and the second distance that are calculated.