Vehicle Low-Beam Segmentation for Forward-Vehicle Glare Reduction

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Solution Overview

Problem

Existing vehicle light fixtures struggle to further reduce glare experienced by drivers of vehicles in front, despite adaptive driving beam (ADB) controls.

Innovation Solution

A vehicle light fixture system with a low-beam unit and light distribution control device that adjusts illuminance in subareas below a cutoff line, forming reduced illuminance portions to overlap with the position of a vehicle in front, using a low-beam and ADB unit to minimize glare.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If illuminance is increased in front of the vehicle to improve viewability for the driver, then the driver's visibility is improved, but glare experienced by drivers of vehicles in front increases

Engineering Contradiction:
Improveilluminance in front of vehicleVSAvoidglare to drivers of vehicles in front
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The light distribution control device divides the illumination area into multiple independently controllable subareas below the cutoff line. By segmenting the low-beam light distribution into discrete zones, the system can selectively reduce illuminance only in subareas that would cause glare to vehicles in front, while maintaining full illuminance in other subareas for driver visibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies different illuminance characteristics to different spatial locations. Specifically, it reduces illuminance locally in subareas overlapping with vehicles in front (first reduced illuminance portions) while maintaining normal illuminance in non-overlapping subareas. This local differentiation resolves the contradiction by making the light distribution adaptive to local conditions rather than uniformly applied.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If adaptive driving beam control is used to dynamically adjust high-beam light distribution, then glare to vehicles in front is reduced, but viewability for the driver's vehicle may be compromised

Engineering Contradiction:
Improveglare to vehicles in frontVSAvoidviewability for driver's vehicle
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The low-beam light distribution is segmented into multiple subareas that can be independently controlled. This segmentation allows the system to maintain high-beam illuminance in most subareas for driver viewability while selectively creating reduced illuminance zones only where vehicles in front are detected, preserving overall visibility while reducing glare.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of reducing illuminance across the entire low-beam distribution, the system applies partial action by reducing illuminance only in specific subareas (first reduced illuminance portions) where vehicles in front are located. This partial application of the glare-reduction measure maintains driver viewability in non-affected areas while still providing glare protection.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4265477B1Vehicle light fixture system, light distribution control device, and light distribution control method
Publication Date: 2025.10.22 KOITO MFG CO LTD
  • EP4265477B1 patent drawingFigure 1
  • EP4265477B1 patent drawingFigure 2A~2B
  • EP4265477B1 patent drawingFigure 3~4

AI summary

A vehicle light fixture system (1) includes: a low-beam unit (2) adapted to form a low-beam light distribution pattern (P5) having a cutoff line (CL) and to independently adjust illuminance in a plurality of subareas (P3) in the low-beam light distribution pattern (P5) arranged below and along the cutoff line (CL); and a light distribution control device (8) that controls the low-beam unit (2) to form a first reduced illuminance portion (46) in, of the plurality of subareas (P3), the subarea (P3) having a position in a vehicle width direction overlapping a position of a vehicle in front (100) in the vehicle width direction.