Vehicular Headlamp Lens Side Wall Light Control

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Solution Overview

Problem

Vehicular headlamps with multiple lighting devices experience steep luminous intensity gradients and streak unevenness due to the reflection of light, leading to unnatural light patterns and reduced driver visibility.

Innovation Solution

Incorporating a first lens with side portion wall surfaces that allow light with lower luminous intensity to enter, combined with a second lens that diffuses and directs light to reduce glare and create a gentle luminous intensity gradient, preventing streak unevenness and improving visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light is reflected by a reflecting plate to apply in a predetermined direction, then light distribution is controlled, but a steep luminous intensity gradient and conspicuous boundary between light and dark occur

Engineering Contradiction:
Improveluminous intensity gradientVSAvoidstreak unevenness
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The first lens is designed with non-uniform thickness, creating different optical path lengths at different locations. The lens thickness varies from the light emitting element outward, with specific thickness ranges (0.5-2.0mm at center, 1.0-3.0mm at edges) to control light distribution locally and create a gentle luminous intensity gradient without steep boundaries

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention transitions from planar light control (reflecting plate) to three-dimensional light control by using a lens with varying thickness in the radial dimension. This dimensional change allows light to be refracted at multiple angles and path lengths, creating a more gradual transition in luminous intensity and eliminating conspicuous boundaries

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If multiple lighting devices are provided to illuminate a wide area, then coverage is improved, but streak unevenness occurs in the combined light distribution

Engineering Contradiction:
Improvelight distribution coverageVSAvoidstreak unevenness
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The lens parameters (thickness, material refractive index) are optimized to control the angular distribution of light. By adjusting the lens thickness profile and material properties, the light from each LED is distributed at specific angles that prevent overlapping boundaries when multiple LEDs are used, creating a uniform combined light distribution across the entire coverage area

Inventive Principle:
Principle #35Parameter changes

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 solution results in a natural light distribution with reduced streak unevenness and improved visibility by blurring the boundary between light and dark, enhancing the overall light distribution and energy efficiency of the headlamp.

Implementation Method 1

a first lens that captures and emits light generated by the light emitting element

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a reflection side surface portion that reflects the light entered the inside of the first lens from the first lens entrance

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a second lens that captures light emitted from the first lens and emits the light in a predetermined direction

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3486550B1Vehicular headlamp
Publication Date: 2022.10.05 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3486550B1 patent drawingFigure 1A
  • EP3486550B1 patent drawingFigure 1B
  • EP3486550B1 patent drawingFigure 2A~2B

AI summary

A lighting device includes a light emitting element; a first lens that captures and emits light generated by the light emitting element; and a second lens that captures light emitted from the first lens and emits the light in a predetermined direction. The first lens includes a first-lens-entrance through which the light generated by the light emitting element enters, a first lens exit that emits the light entered from the first-lens-entrance and transmitted through an inside of the first lens, and a plurality of first-lens-side-portion-wall-surfaces that are provided between the first-lens-entrance and the first lens exit. The plurality of first-lens-side-portion-wall-surfaces include a reflection-side-surface-portion that reflects the light entered the inside of the first lens from the first-lens-entrance, and a side surface portion that is configured to allow light having a luminous intensity smaller than a luminous intensity of light entering the reflection-side-surface-portion to enter.