Segmented Illumination Lens for HUD Uniformity
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Solution Overview
Problem
Illumination lenses in head-up display devices suffer from illuminance unevenness due to varying light intensity along the optical axis, leading to inconsistent illumination of the display.
Innovation Solution
The illumination lens features alternately arranged first and second lens surface parts, with the first lens surface parts being at least twice differentiable along the first optical axis and the second lens surface parts being at least once differentiable along a parallel second optical axis, allowing for superimposed light emission to enhance intensity distribution and reduce unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the lens surface is made twice differentiable for smooth light condensing, then the light condensing function is improved, but the manufacturing complexity increases
Solution Approach 1:
Instead of making the entire lens surface twice differentiable, the invention segments the lens into multiple parts where only the first lens surface parts require twice differentiability. The second lens surface parts can have lower differentiability requirements, thus reducing overall manufacturing complexity while maintaining optical performance.
Solution Approach 2:
Different regions of the lens are assigned different levels of surface smoothness requirements. The first lens surface parts, which directly handle light from the light source, are made twice differentiable for optimal light condensing. The second lens surface parts, which handle deviated optical axes, have relaxed differentiability requirements, optimizing the balance between optical performance and manufacturing ease.
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 increases light intensity off-axis and reduces illuminance unevenness, providing a more consistent and uniform illumination for the display, thereby improving the visibility of virtual images.
Implementation Method 1
an illumination lens is used for condensing a light from a light source and emitting the light toward an illumination target
Data Source
AI summary
An illumination lens condenses a light from a light source and emits the light toward a display to illuminate the display. The illumination lens includes multiple first lens surface parts having a shape obtained by extracting multiple portions of a first virtual lens surface along a first optical axis, the first virtual lens surface defining the first optical axis on which the light source is disposed and being at least twice differentiable between optical axes arranged in a reference direction, and multiple second lens surface parts having a shape obtained by extracting multiple portions of a second virtual lens surface along a second optical axis, the second virtual lens surface defining the second optical axis and being at least once differentiable between the optical axes arranged in the reference direction. The first lens surface parts and the second lens surface parts are alternately arranged in the reference direction.