Keystone Correction for Projection Terminals at Large Angles
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Solution Overview
Problem
Existing keystone correction technologies for projection terminals are ineffective when the included angle between the projection centerline and the horizontal plane is greater than a certain angle, leading to uncertainty about the direction of the projection plane, resulting in poor correction effects.
Innovation Solution
Determining the direction of the projection plane based on the size relationship between distances along different projection lines with varying angles, allowing for accurate keystone correction by adjusting the included angle calculation accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the included angle between the projection centerline and the horizontal plane is large, then the projection terminal can be placed in more flexible positions, but the keystone correction effect deteriorates due to uncertainty in determining the projection plane direction
Solution Approach 1:
The patent transitions from two-dimensional angle measurement (accelerometer detecting angle relative to horizontal plane) to three-dimensional spatial relationship analysis by measuring distances along multiple projection lines with different angles. This dimensional expansion enables accurate determination of projection plane direction even when the included angle is large, resolving the contradiction between placement flexibility and measurement precision.
Solution Approach 2:
The patent introduces distance measurements along different projection lines as intermediary data to indirectly determine the projection plane direction. Instead of directly measuring the angle between projection centerline and projection plane, the system uses distance variations as mediators to infer the correct orientation, enabling accurate keystone correction in challenging angular positions.
2Device complexity
If automatic keystone correction is performed based solely on the included angle between the projection centerline and the horizontal plane, then the correction process is simple, but the correction effect deteriorates when the projection plane direction cannot be uniquely determined
Solution Approach 1:
The patent segments the correction process into two distinct phases: first determining the projection plane direction using distance measurements along multiple projection lines, then performing keystone correction based on the determined direction. This segmentation allows the system to handle complex scenarios reliably while maintaining computational efficiency through modular processing.
Solution Approach 2:
The patent performs preliminary determination of the projection plane direction before executing the keystone correction. By pre-establishing the correct orientation through distance-based analysis, the subsequent correction process becomes more reliable and accurate, avoiding the pitfalls of direct angle-based correction in ambiguous situations.
Data Source
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AI summary
Embodiments of the present invention disclose a keystone correction method for a projection terminal including: when an included angle between a projection centerline of the projection terminal and a horizontal plane is greater than a set acute angle, determining a direction of a projection plane according to a size relationship between a distance of the projection terminal to the projection plane along a first projection line and a distance of the projection terminal to the projection plane along a second projection line, the first projection line and the second projection line having different projection angles; and performing a keystone correction for the projection terminal according to the direction of the projection plane. Embodiments of the present invention further disclose a keystone correction device for a projection terminal, a projection terminal and a computer storage medium.