Vehicle Lamp Optical Stack Using Cholesteric Liquid Crystal Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light emitting diodes used in vehicle lamps face issues with limited light emitting area, non-uniform light distribution, and visibility of the light source, which affects design freedom and aesthetics.
Innovation Solution
A lighting device comprising a substrate, reflective layer, and light-transmission control layer with a cholesteric liquid crystal layer that operates in reflection, scattering, or transmission modes, along with a light-blocking sheet and wavelength conversion layer to enhance light distribution and conceal the light source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a light emitting diode is used as a vehicle lamp, then power consumption is reduced and lifespan is extended, but the light emitting area is limited and light distribution is non-uniform
Solution Approach 1:
The light emitting diode is divided into multiple light emitting units arranged in an array, where each unit contributes to the overall light output. This segmentation increases the total light emitting area while maintaining the energy efficiency of individual LED units
Solution Approach 2:
The patent transitions from point-source LED emission to a two-dimensional light emitting surface by arranging multiple LED units in a grid pattern. This dimensional expansion creates a surface light source that provides uniform illumination across a larger area
2Speed
If a light emitting diode is used as a vehicle lamp, then response speed is improved, but hot spots are formed and uniformity characteristics are deteriorated
Solution Approach 1:
The patent applies local quality by varying the intensity or activation state of individual LED units within the array based on their position. This allows hot spots to be compensated for by adjusting local emission characteristics, achieving uniform overall illumination while maintaining fast LED response
Solution Approach 2:
The patent uses more LED units than traditionally required, activating only the necessary portions to achieve uniform illumination. This excessive arrangement of light emitting units allows selective activation to prevent hot spots while maintaining rapid response capability
3Reliability
If a light emitting diode is used as a vehicle lamp, then safety and environmental friendliness are improved, but the light emitting diode is visually recognized and aesthetic freedom is deteriorated
Solution Approach 1:
The patent utilizes the ability of LEDs to change color or intensity to achieve aesthetic effects. The light emitting surface can be configured to appear as a uniform colored panel when off, and transitions to functional lighting patterns when activated, providing both safety and design freedom
Solution Approach 2:
The patent changes the optical parameters of the light emitting surface by controlling the intensity and distribution of individual LED units. This allows the same LED array to provide different visual appearances for aesthetic purposes while maintaining safety functionality
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
The device provides a uniform light source with improved luminance, reduced visibility, and enhanced design flexibility, while effectively dissipating heat and maintaining aesthetic appeal.
Implementation Method 1
a light-transmission control layer which includes a liquid crystal layer including cholesteric liquid crystal
Implementation Method 2
light emitted through the light emitting surface of the light emitting device is reflected by the reflective layer
Implementation Method 3
the liquid crystal layer may operate in one mode selected from reflection mode (Planner), scattering mode (Focal Conic), and transmission mode (Homeotropic)
Implementation Method 4
a wavelength conversion layer disposed between the second resin layer and the light-transmission control layer
Implementation Method 5
a light emitting device disposed on a lower surface of the substrate
Implementation Method 6
a light emitting diode (LED)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The lighting device disclosed in the embodiment includes a substrate, a light emitting device disposed on a lower surface of the substrate, a reflective layer disposed to face a light emitting surface of the light emitting device, a first resin layer disposed between the substrate and the reflective layer, and a light-transmission control layer disposed on an upper surface of the substrate, wherein the light-transmission control layer may include a liquid crystal layer including a cholesteric liquid crystal, and light emitted through the light emitting surface of the light emitting device may be reflected by the reflective layer and be provided to the light-transmission control layer through the substrate.