Vehicle Lighting Fixture With Light Guide Portion
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Solution Overview
Problem
Conventional vehicle lighting fixtures experience luminous intensity unevenness and reduced light distribution feeling due to high luminous intensity at certain angles and non-uniform vertical thickness in low-beam light distribution patterns.
Innovation Solution
A vehicle lighting fixture design incorporating a separator with a specific light guide portion configuration, including an upper and lower separator body, and a projection lens with a focal plane that adjusts the optical path to distribute light uniformly, reducing luminous intensity at specific angles and maintaining uniform vertical thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional projection lens and light guide lens are used to form a low-beam light distribution pattern, then the legal requirements for light distribution are satisfied, but the luminous intensity at certain angles (e.g., 4 degrees below horizontal) becomes relatively high causing luminous intensity unevenness
Solution Approach 1:
The invention divides the light guide lens into multiple segments: a first light guide portion and a second light guide portion with different optical characteristics. The first light guide portion controls light in the horizontal direction while the second light guide portion controls light in the vertical direction, allowing independent optimization of luminous intensity distribution in different directions to eliminate hot spots and achieve uniform illumination.
Solution Approach 2:
Different regions of the light guide lens are given different optical properties. The first light guide portion has specific refractive index and curvature designed for horizontal light control, while the second light guide portion has different parameters optimized for vertical light control. This local differentiation allows precise control of luminous intensity at different angular positions.
2Ease of operation
If a conventional projection lens system is used, then the basic low-beam function is achieved, but the vertical thickness of the central portion becomes smaller than at the left and right ends reducing light distribution feeling
Solution Approach 1:
The light guide lens employs asymmetric design where the first light guide portion and second light guide portion have different geometries and optical parameters. The first light guide portion extends primarily in the horizontal direction with specific curvature, while the second light guide portion extends in the vertical direction with different curvature and thickness characteristics, enabling independent control of light distribution in different directions.
Solution Approach 2:
The invention addresses the two-dimensional thickness uniformity problem by introducing a third dimension through the asymmetric three-dimensional structure of the light guide lens. By designing different portions with varying thicknesses and curvatures in three-dimensional space, the system achieves uniform vertical thickness projection in the final light distribution pattern.
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 design effectively suppresses high luminous intensity at angles like 4 degrees below the horizontal line and ensures uniform vertical thickness, enhancing the light distribution feeling and meeting legal requirements for low-beam light distribution patterns.
Implementation Method 1
a separator (50A) disposed in front of the low-beam light source (32a) and having a light guide portion (52d) that guides light from the low-beam light source (32a)
Implementation Method 2
a projection lens constituted by a first lens (60A, 60) and a second lens (80), a light guide lens (52d, 53d) disposed behind the projection lens
Data Source
Figure 1
Figure 2~2(c)
Figure 3
AI summary
Provided is a vehicle lighting fixture capable of suppressing the luminous intensity at a portion (e.g., a portion around 4 degrees below the horizontal line) of a low-beam light distribution pattern from becoming relatively high, and also capable of forming a low-beam light distribution pattern with a uniform vertical thickness with respect to the horizontal direction. The vehicle lighting fixture includes a projection lens, a separator disposed behind the projection lens, and a low-beam light source that is disposed behind the separator and emits light for forming a low-beam light distribution pattern by being irradiated forward through the separator and the projection lens in this order. This vehicle lighting fixture is characterized in that: the separator includes an upper separator body that has a front surface and a rear surface on the opposite side thereof, and a first light guide portion that extends from a lower portion of the upper separator body toward the low-beam light source and has a first light incident surface located at a tip end thereof and faces the low-beam light source; that the projection lens has a front surface and a rear surface on the opposite side thereof, and the rear surface of the projection lens has an upper light incident surface facing the front surface of the upper separate body; that the low-beam light source, the first light guide portion, the upper separator body, and the upper light incident surface are each disposed above a reference axis passing through the focal point of the projection lens and extending in a vehicle longitudinal direction; that the lower portion of the front surface of the upper separator body is in surface contact with the lower portion of the upper light incident surface of the rear surface of the projection lens; and that a space is formed between a portion above the lower portion of the front surface of the upper separator body and a portion above the lower portion of the upper light incident surface of the rear surface of the projection lens.