Projection Headlight Lens Grooves to Prevent Pattern Blur

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Solution Overview

Problem

Existing vehicle headlights with multiple light sources can cause blurring of the illumination pattern due to light entering the projection lens from positions offset in the left-right direction, leading to a blurred illumination pattern.

Innovation Solution

The vehicle headlight incorporates a light-source-side lens with groove portions offset from the optical axis in the left-right direction, featuring inclined portions that refract light towards the optical axis, and an exit surface with curved portions to ensure light is directed closer to the optical axis, minimizing aberration and blurring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If light sources are disposed at positions away from the center of the projection lens in the left-right direction, then the lighting coverage area is improved, but the illumination pattern becomes blurred

Engineering Contradiction:
Improvelighting coverage areaVSAvoidillumination pattern clarity
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The light-source-side lens acts as an intermediary component between the light sources and the projection lens. It includes groove portions with inclined portions that refract light from light sources positioned away from the optical axis toward the optical axis, serving as a mediator that corrects the light paths to prevent blurring while maintaining extended lighting coverage

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The incident surface of the light-source-side lens has non-uniform local structures (groove portions) at different positions. The groove portions are disposed at specific positions offset from the optical axis and have inclined portions that locally refract light toward the optical axis, creating different light control characteristics at different locations to simultaneously achieve wide coverage and sharp focus

Inventive Principle:
Principle #3Local quality

2Area of stationary object

If light enters the projection lens from positions offset in the left-right direction, then the field of view is expanded, but aberration increases causing pattern blurring

Engineering Contradiction:
Improvefield of viewVSAvoidaberration
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The groove portions with inclined portions convert the harmful effect of light entering at oblique angles (which causes aberration) into a beneficial effect by refracting this off-axis light toward the optical axis. The inclined portions are specifically designed to redirect light from peripheral positions toward the center, transforming potential aberration sources into focused illumination that maintains pattern clarity while preserving expanded field of view

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This configuration inhibits blurring of the illumination pattern by ensuring light is focused closer to the optical axis, enhancing light usage efficiency and reducing aberration effects, particularly at positions farther from the center.

Implementation Method 1

The groove portion includes an inclined portion that refracts the light from the light sources toward a side closer to the optical axis

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4696926A1Vehicle headlight
Publication Date: 2026.02.18 ICHIKOH IND LTD
  • EP4696926A1 patent drawingFigure 1
  • EP4696926A1 patent drawingFigure 2
  • EP4696926A1 patent drawingFigure 3

AI summary

A vehicle headlight includes: a plurality of light sources disposed in a left-right direction; a light-source-side lens disposed in front of the light sources and emitting light forward; and a projection lens disposed in front of the light-source-side lens and emitting, in front of a vehicle, the light emitted from the light-source-side lens. The light-source-side lens includes an incident surface through which light from the light sources enters. The incident surface includes at least one groove portion disposed at a position offset from an optical axis of the projection lens in the left-right direction and extending in an up-down direction. The groove portion includes an inclined portion that refracts the light from the light sources toward a side closer to the optical axis.