Prism Sheet Light Guide for Louver-Free Emission Angle Control
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Solution Overview
Problem
Existing illumination devices in vehicles use louvers to regulate light emission angles and prevent windshield reflections, which are costly and inefficient.
Innovation Solution
An illumination device comprising a light guide plate with inclined surfaces and prism sheets that control light emission angles without the need for louvers, utilizing a combination of prism sheets with asymmetric and symmetric prisms to enhance light usage efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a louver is used to regulate light emission angle and prevent windshield reflection, then light emission control is improved, but device cost and complexity increase
Solution Approach 1:
The patent replaces the mechanical louver system with optical elements (prism sheets and light guide plate with inclined surfaces) that use refraction and reflection principles to control light emission angles. This substitution eliminates the need for movable mechanical parts while achieving the same light regulation function, thereby reducing device complexity and cost.
Solution Approach 2:
The patent introduces prism sheets and inclined surfaces on the light guide plate as intermediary optical elements between the light source and the display surface. These intermediaries control light propagation paths through refraction and reflection, achieving emission angle regulation without requiring direct mechanical intervention like louvers.
2Object-affected harmful factors
If a louver is used to prevent windshield reflection, then reflection prevention is improved, but device cost increases
Solution Approach 1:
The patent replaces the expensive mechanical louver system with cost-effective optical elements (prism sheets and light guide plate structures) that control light paths through optical principles. This substitution significantly reduces manufacturing costs while maintaining the reflection prevention function.
Solution Approach 2:
The patent changes the optical parameters (refraction angles, reflection angles) by designing specific prism geometries and light guide plate inclined surfaces. By optimizing these parameters, the system controls light emission angles to prevent windshield reflection without requiring expensive mechanical components.
3Use of energy by moving object
If prism sheets with asymmetric and symmetric prisms are used to enhance light condensation, then light usage efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent divides the light control function into multiple segments: the light guide plate with inclined surfaces handles initial light direction control, while the prism sheets (with both asymmetric and symmetric prisms) provide further refinement. This segmentation allows each component to have optimized, simpler geometries that are easier to manufacture with high precision compared to a single complex element.
Solution Approach 2:
The patent employs both asymmetric and symmetric prism designs in the prism sheets. The asymmetric prisms handle specific light paths requiring directional control, while symmetric prisms handle other paths. This combination allows optimization of light condensation for different regions and angles, improving overall light usage efficiency while enabling modular manufacturing approaches.
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
Effectively regulates light emission angles and improves light usage efficiency by reducing side lobes and enhancing light condensation, thereby optimizing illumination without the use of costly louvers.
Implementation Method 1
the second main surface of the light guide plate is provided with a first inclined surface that is an inclination rising from a side opposite to the light source side toward the light source side
Implementation Method 2
the fourth main surface of the first prism sheet is provided with a plurality of first prisms extending along the first direction and arranged along a second direction intersecting the first direction
Data Source
AI summary
An illumination device that includes a light source, a light guide plate featuring a first end face, a first main surface, a second main surface, and a first prism sheet is provided. The first prism sheet includes a third main surface, facing the second main surface of the light guide plate, and a fourth main surface. The second main surface of the light guide plate is provided with a first inclined surface that has an inclination rising from a side opposite the light source side toward the light source side in a first direction. The fourth main surface of the first prism sheet is provided with multiple first prisms extending along the first direction and disposed along a second direction. Each first prism includes a first base parallel to the second direction, and a pair of first oblique sides rising from both ends of the first base.