Interactive Projector Camera Arrangement for Distance Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing interactive projectors have insufficient detection accuracy for the distance between a pointing element and the screen, which affects the precision of user instructions.
Innovation Solution
The interactive projector employs two cameras with specific optical axis orientations and arrangements to capture images of the pointing element, ensuring higher resolution in the normal direction of the projected screen, allowing for more accurate distance determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single camera is used to detect the pointing element position, then the device complexity is low, but the measurement precision of the distance between the pointing element and the screen is insufficient
Solution Approach 1:
The patent transitions from single-camera two-dimensional imaging to multi-camera three-dimensional imaging. By arranging multiple cameras at different positions and orientations relative to the screen normal, the system captures depth information and enables accurate distance measurement of the pointing element from the screen, resolving the measurement precision limitation of single-camera systems.
Solution Approach 2:
The detection function is segmented across multiple cameras rather than relying on a single camera. Each camera is positioned and oriented differently to capture specific spatial information, with at least one camera having its optical axis more aligned with the screen normal to optimize distance measurement capability.
2Measurement precision
If the camera optical axis is perpendicular to the screen surface, then the distance measurement is optimized, but the resolution in the normal direction of the screen decreases
Solution Approach 1:
The patent uses multiple cameras positioned at different angular orientations relative to the screen normal. This multi-dimensional arrangement allows the system to combine depth information from various angles, achieving accurate distance measurement while maintaining adequate image resolution through the collective data from all cameras.
Solution Approach 2:
Different cameras are assigned different functional roles based on their orientation. At least one camera is optimized for distance measurement with its optical axis aligned closer to the screen normal, while other cameras provide complementary viewing angles. This local optimization ensures that each camera contributes its strongest capability to the overall system performance.
Data Source
AI summary
An interactive projector includes a projection section, a plurality of cameras, and a position detection section for detecting a three-dimensional position of the pointing element based on images captured by the plurality of cameras. Defining a unit vector representing a normal direction of the projected screen as a projected-screen normal vector, a unit vector representing a direction of an optical axis of the first camera as a first optical axis vector, and a unit vector representing a direction of an optical axis of the second camera as a second optical axis vector, the first camera and the second camera are arranged such that an absolute value of an inner product of the second optical axis vector and the projected-screen normal vector is smaller than an absolute value of an inner product of the first optical axis vector and the projected-screen normal vector.