Curved-Surface Reflection Device for Projection Light Loss
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Solution Overview
Problem
Conventional projection apparatuses suffer from light loss due to the rectangular contour of digital micro-mirror devices (DMDs) and lens arrays, leading to crosstalk and reduced light use efficiency, especially when trying to display widescreen images with non-matching aspect ratios.
Innovation Solution
A projection apparatus utilizing a curved-surface reflection device and a light uniforming device with rectangular lenses, where the curvature and diopter of optical components are adjusted to shape the illumination beam into a rectangular shape matching the DMD's active surface, broadening the valid light collection angle and preventing light deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the aspect ratio of lens cells is matched to the DMD (16:9 for widescreen), then the light spot shape is improved, but the valid light collection angle in the direction parallel to the short side becomes smaller causing light loss
Solution Approach 1:
The patent applies asymmetry by using a curved-surface reflection device with different curvatures in different directions (first curvature in first direction, second curvature in second direction). This asymmetric curvature design allows the device to broaden the light collection angle specifically in the direction where light loss occurs (parallel to the short side of lens cells), while maintaining the rectangular light spot shape on the DMD surface.
2Adaptability or versatility
If a rectangular DMD is used to display widescreen images, then the image aspect ratio is improved, but light deviation occurs causing crosstalk and reduced light use efficiency
Solution Approach 1:
The curved-surface reflection device implements local quality by having different curvature radii in different directional regions. The first curvature in the first direction and the second curvature in the second direction are specifically designed to control light propagation paths locally, ensuring that light beams are properly directed to corresponding lens cells across the entire rectangular DMD surface, thereby preventing crosstalk and improving light use efficiency for widescreen displays.
3Shape
If the short side of lens cells is made shorter to achieve widescreen aspect ratio, then the light spot shape is improved, but the valid light collection angle becomes smaller causing more light loss
Solution Approach 1:
The curved-surface reflection device serves as an intermediary component between the light source and the lens array. It mediates the light propagation by reshaping the illumination beam before it reaches the lens cells, effectively compensating for the reduced light collection angle caused by the shorter short side of the lens cells. This intermediary device ensures sufficient light reaches each lens cell without requiring larger lens cell dimensions.
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 configuration increases the quantity of illumination reaching the DMD, enhancing light use efficiency and enabling the projection of images with various aspect ratios without significant light loss.
Implementation Method 1
The first curved-surface reflection device is disposed on the transmission path of the illumination beam and between the light source and the light valve. The first curved-surface reflection device is configured to reflect the illumination beam to the light valve.
Data Source
AI summary
A projection apparatus including a light source, a light valve, a light uniforming device, and a first curved-surface reflection device is provided. The light source provides an illumination beam. The light valve is disposed on a transmission path of the illumination beam for converting the illumination beam into an image beam. The light valve has an active surface that substantially has a rectangular contour. The light uniforming device is disposed on the transmission path of the illumination beam and between the light source and the light valve. The first curved-surface reflection device is disposed on the transmission path of the illumination beam and between the light source and the light valve for reflecting the illumination beam to the light valve. A curvature of the first curved-surface reflection device along a first direction is not equal to a curvature of the first curved-surface reflection device along a second direction.