Vehicle Headlight Device Using Rotating Mirror and Micro Mirrors

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Solution Overview

Problem

Conventional vehicle headlight systems face inefficiencies in light utilization and reduced contrast in information displaying light, particularly due to the reflection method used by Digital Mirror Devices and the scanning of laser light, which affects visibility for pedestrians.

Innovation Solution

A vehicle headlight device incorporating a high beam unit with a rotating mirror to create scanning light, a second illuminating unit with adjustable micro mirrors for information displaying light, and a controlling unit to manage the illumination regions, reducing light waste and enhancing contrast through a common projection lens for both light types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a DMD reflects light to form a pattern, then the pattern can be displayed, but regions not needed for the pattern reflect light in other directions causing decreased light utilization efficiency

Engineering Contradiction:
Improvepattern formation capabilityVSAvoidlight utilization efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent extracts only the necessary light-reflection function by replacing the DMD with a simple reflective plate. The reflective plate merely reflects light from the light source through the projection lens without actively directing light to specific regions, thereby eliminating wasted light reflection while maintaining pattern formation capability through the projection lens alone.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a complex device (DMD) to actively direct light to form patterns, the patent inverts the approach by using a simple reflective plate and relying on the projection lens to define the illumination pattern. This reverses the traditional approach of pattern formation and significantly improves light utilization efficiency.

Inventive Principle:
Principle #13The other way round (Inversion)

2Loss of information

If laser light is scanned to display a drawn pattern, then information can be displayed, but the contrast is low at both end portions causing deteriorated visibility

Engineering Contradiction:
Improveinformation display capabilityVSAvoidcontrast of drawn pattern
Core Design Contradiction:
Loss of informationVSIllumination intensity

Solution Approach 1:

The patent removes the laser scanning mechanism entirely and extracts only the essential function of illuminating information. By using a light source with a condensing lens and reflective plate, the system eliminates the contrast deterioration issue inherent in laser scanning while maintaining information display capability through direct optical projection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical laser scanning system with a static optical projection system using a light source, condensing lens, and reflective plate. This substitution eliminates the mechanical scanning process that causes contrast loss at end portions, providing uniform and high-contrast information display throughout the entire illumination area.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If separate projection lenses are used for scanning light and information displaying light, then each light type can be optimized, but the number of parts increases

Engineering Contradiction:
Improvelight type optimizationVSAvoidnumber of projection lenses
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the projection functions for different light types into a single projection lens. The reflective plate is positioned to reflect both high beam light and information displaying light through the same projection lens, thereby reducing the number of parts while maintaining the ability to optimize illumination for different purposes through control of the light source and reflective plate positioning.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The projection lens is designed to serve multiple functions: projecting high beam illumination and projecting information displaying light. The reflective plate and light source system is configured to direct different types of light through the same optical path, making the projection lens universal and reducing overall system complexity while maintaining optimization capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 suppresses the decrease in light efficiency and contrast, simplifies the illumination region shape, reduces the number of parts, and provides efficient caution alerts to pedestrians with improved visibility.

Implementation Method 1

a first mirror that rotates, the first mirror reflecting laser light that has exited from a laser light source, making the laser light into scanning light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a second mirror that is an aggregate of a plurality of micro mirrors having angles that can be changed, the second mirror reflecting visible light that has exited from a visible light source, making the visible light into information displaying light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a common projection lens that transmits therethrough the scanning light and illuminates the scanning light toward the first illumination region, and that transmits therethrough the information displaying light and illuminates the information displaying light toward the second illumination region

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3483498B1Vehicle headlight device
Publication Date: 2023.01.25 TOYOTA JIDOSHA KK
  • EP3483498B1 patent drawingFigure 1
  • EP3483498B1 patent drawingFigure 2
  • EP3483498B1 patent drawingFigure 3

AI summary

A vehicle headlight device includes: a first illuminating unit (18) for reflecting, at a first mirror (22, 42, 44) that rotates, laser light that has exited from a laser light source (20) and making the laser light into scanning light, and a illuminating the scanning light toward a first illumination region (Ha) that is in front of a vehicle; second illuminating unit (17) for reflecting, at a second mirror (34) that is an aggregate of plural micro mirrors whose angles can be changed, visible light that has exited from a visible light source (30) and making the visible light into information displaying light, and illuminating the information displaying light toward a second illumination region (Da) that is in front of the vehicle; and controlling unit (40) for controlling turning-off and turning-on of the laser light source (20), rotating operation of the first mirror (22, 42, 44), and changing of the angles of the micro mirrors at the second mirror (40).