Vehicular Lamp Unit with Reflective Polarizing Plate
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Solution Overview
Problem
Conventional vehicular headlamps using liquid crystal elements suffer from low light utilization efficiency due to the transmittance of polarizers being approximately 35% or less, leading to inefficiencies in light distribution.
Innovation Solution
A vehicular lamp unit configuration that includes a collimating lens, reflective polarizing plate, liquid crystal device, polarizing plate, and projection lens, with optimized alignment and use of phase difference plates to enhance light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a liquid crystal element with polarizers is used as a light shielding part, then selective light control according to the shape of the light distribution pattern is achieved, but light utilization efficiency is decreased to approximately 35% or less
Solution Approach 1:
A phase difference plate is introduced as an intermediary component between the liquid crystal layer and the polarizing plate. This plate modifies the polarization state of light passing through the liquid crystal, enabling more efficient light transmission while maintaining the selective light control function. The phase difference plate acts as a mediator that transforms the polarization characteristics to improve overall light utilization efficiency.
Solution Approach 2:
The invention changes the optical parameters of the system by introducing a phase difference plate with specific retardation characteristics. This alters the polarization state transformation in the optical path, allowing the liquid crystal element to achieve both selective light control and improved transmission efficiency by modifying how light interacts with the polarizers.
2Ease of operation
If polarizing plates are configured as components of the liquid crystal element, then light shielding and light distribution pattern control are achieved, but light absorption by polarizers reduces transmittance to approximately 35% or less
Solution Approach 1:
The phase difference plate serves as an intermediary that modifies the polarization state of light between the liquid crystal layer and the polarizing plate. By transforming the polarization characteristics, it enables the system to maintain effective light distribution pattern control while significantly improving light transmittance and reducing absorption losses.
Solution Approach 2:
The introduction of the phase difference plate changes the optical parameters of the system, specifically the polarization state transformation. This parameter change allows the polarizing plates to function more efficiently, maintaining their light distribution control capability while increasing overall light transmittance above the conventional 35% limitation.
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 configuration significantly improves light utilization efficiency by effectively directing and modulating light to form desired distribution patterns, enhancing the vehicular lamp's performance.
Implementation Method 1
a collimating lens that collimates light emitted from the light source
Implementation Method 2
a reflective polarizing plate that is disposed at an oblique angle with respect to the liquid crystal device
Implementation Method 3
a reflective polarizing plate
Implementation Method 4
a liquid crystal device that is disposed on the light source side of the reflective polarizing plate
Implementation Method 5
a projection lens that emits light having passed through the liquid crystal device and the polarizing plate
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
To increase the light utilization efficiency when selective light irradiation is performed using a liquid crystal element (a liquid crystal device). A lamp unit including: (a) a light source; (b) a reflective polarizing plate disposed at a position where light from the light source is incident; (c) a reflecting mirror configured to reflect a reflected light generated by the reflective polarizing plate and re-enters the reflected light to the reflective polarizing plate; (d) a liquid crystal device disposed on the light emitting surface side of the reflective polarizing plate; (e) a polarizing plate disposed on the light emitting surface side of the liquid crystal device; and (f) a lens disposed on the light emitting surface side of the polarizing plate.