Off-Axis LCD Projector Eliminates Trapezoidal Distortion
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Solution Overview
Problem
Existing single LCD projectors suffer from trapezoidal distortion within the projection range of 40-120 inches, limiting their application and image quality.
Innovation Solution
The implementation of an off-axis LCD projection technology, where the optical axis of the projection lens is arranged parallel to the system optical axis with a specific distance, combined with oblique illumination and an eccentric arrangement of the front Fresnel lens, eliminates trapezoidal distortion and enhances image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single LCD projector uses conventional coaxial optical design, then the structure is simple and cost is low, but trapezoidal distortion occurs in the projection range of 40-120 inches
Solution Approach 1:
The patent applies asymmetry by designing an off-axis optical system where the projection lens optical axis is deliberately offset from the system optical axis. This asymmetric arrangement eliminates trapezoidal distortion in the projection range of 40-120 inches while maintaining relatively simple structure. The optical axis of the projection lens is positioned at a specific distance from the system optical axis, creating an asymmetric optical path that corrects geometric distortion without requiring complex additional components.
2Manufacturing precision
If the optical axis of the projection lens is arranged parallel to the system optical axis with a specific distance, then trapezoidal distortion is eliminated, but the device complexity increases
Solution Approach 1:
The patent changes the positional parameter of the projection lens optical axis relative to the system optical axis. By setting the optical axis of the projection lens parallel to but offset from the system optical axis by a specific distance, the system achieves distortion-free projection. This parameter change (off-axis distance) is optimized to eliminate trapezoidal distortion while keeping the optical system relatively simple, avoiding the need for complex mechanical adjustment mechanisms or additional optical elements.
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 solution achieves a trapezoidal distortion-free projection within the specified range, improving brightness, uniformity, and image quality, while maintaining a compact projector design.
Implementation Method 1
a first lens and a projection lens; the projector is configured such that the light emitted by the light source can sequentially pass through the display panel, the first lens, the projection lens and then exit
Implementation Method 2
the eccentric arrangement of the front Fresnel lens
Data Source
AI summary
The present disclosure provides a projector. The projector includes a light source, a display panel, a first lens and a projection lens. The projector is configured such that the light emitted by the light source can sequentially pass through the display panel, the first lens, the projection lens and then exit. The projector includes a system optical axis, and the optical axis of the display panel coincides with the system optical axis; the optical axis of the projection lens is arranged parallel to the system optical axis with a distance therefrom.