Projector Lens Array Curvature for Brightness Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Projectors face issues with brightness irregularities due to displacement of the light emitting part, which affects the in-plane light intensity distribution and results in projection images with noticeable brightness and color irregularities.
Innovation Solution
The projector incorporates a first lens array with plano-convex lenses having spherical curved surfaces, where the radii of curvature are set for each lens to reduce in-plane light intensity irregularities, and includes a guiding optical system to invert the light intensity distribution of each color light, thereby minimizing brightness and color irregularities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light source with high intensity is used to improve projection brightness, then the projection image becomes brighter, but brightness irregularities increase due to displacement of the light emitting part
Solution Approach 1:
The patent applies local quality by setting different radii of curvature for each first small lens in the lens array. Specifically, lenses at different positions (corner, edge, center) have different radius of curvature values to compensate for position-dependent light intensity irregularities caused by light emitting part displacement. This localized optimization of lens parameters ensures uniform light distribution across the entire projection area while maintaining high overall brightness.
2Reliability
If the light emitting part is displaced due to aging or vibration, then the projection system remains operational, but brightness irregularities increase
Solution Approach 1:
The patent implements beforehand cushioning by pre-configuring the lens array with specific radius of curvature values designed to compensate for expected light emitting part displacements. The radius of curvature is set in advance to counteract the effects of aging and vibration that will occur during operation, thereby maintaining uniform brightness even when displacement happens. This proactive design approach cushions against future degradation without requiring active adjustment mechanisms.
3Manufacturing precision
If uniform light distribution is achieved using lens arrays, then brightness irregularities are reduced, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by varying the radius of curvature parameter of the first small lenses based on their positions in the array. Instead of using identical lenses throughout, the radius of curvature is adjusted as a function of position (corner, edge, center), allowing the optical system to achieve uniform light distribution with a relatively simple lens array structure. This parameter optimization approach reduces complexity compared to more complex optical designs while maintaining high light intensity uniformity.
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 effectively reduces brightness and color irregularities in the projected image, even when using high-intensity arc tubes prone to displacement, by uniformly distributing light intensity and compensating for color differences, resulting in a more stable and uniform projection.
Implementation Method 1
a first lens array having plural first small lenses, a second lens array having plural second small lenses corresponding to the plural first small lenses, and a superimposing lens that superimposes lights from the second lens array
Data Source
AI summary
A projector includes an illumination device including a light source that outputs light from a light emitting part, a first lens array having plural first small lenses, a second lens array having plural second small lenses corresponding to the plural first small lenses, and a superimposing lens that superimposes lights from the second lens array, a light modulation device that modulates light from the illumination device in response to image information, and a projection optical system that projects the light from the light modulation device on a projection target, wherein radii of curvature of the first small lenses are set with respect to each first small lens.