Piezoelectric Lens Actuator for Slim Headlamp Beam Steering

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Solution Overview

Problem

Vehicle headlamps face challenges in controlling light radiation direction due to size constraints and the need for actuators, which are large and difficult to integrate in small or slim lamp designs, especially when multiple optical modules are involved.

Innovation Solution

A lighting device with a housing, a changeable lens unit, a length-variable unit that adjusts position in response to electricity, and a controller to control light radiation direction, eliminating the need for large actuators by using a piezoelectric element to bend and change the lens unit's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an actuator is used to aim an optical module, then the light radiation direction can be controlled, but the device volume increases and it becomes difficult to make headlamps small or slim

Engineering Contradiction:

Improvelight radiation direction controlVSAvoidheadlamp volume

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

The patent replaces the traditional mechanical actuator system with a photonic crystal lens system that uses optical properties to achieve aiming control. The photonic crystal lens changes its light refraction characteristics based on temperature-induced structural changes, eliminating the need for large mechanical actuators and reducing overall device volume while maintaining direction control capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes temperature as a control parameter to change the refractive index and focal length of the photonic crystal lens. By applying heat or cooling to the lens, its optical parameters change, which in turn changes the light radiation direction. This parameter-based control method replaces mechanical movement with optical property modification, reducing the need for large mechanical components.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If multiple optical modules are provided, then lighting coverage is improved, but each module requires an individual actuator making it difficult to reduce overall size

Engineering Contradiction:

Improvelighting coverageVSAvoidoverall device volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent employs multiple photonic crystal lens modules that share the same compact design and control mechanism. Each lens module is independently controllable through temperature adjustment, allowing multiple lighting patterns and coverage areas without requiring proportionally larger actuators. The uniform compact design across multiple modules enables versatile lighting coverage while maintaining small overall volume.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If the headlamps are fixedly mounted, then installation is simple, but they may dazzle other drivers or fail to illuminate the field of view appropriately depending on driving conditions

Engineering Contradiction:

Improveinstallation simplicityVSAvoidlight radiation adaptability

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed headlamp design into a dynamic system where the photonic crystal lenses can change their optical characteristics in real-time. The lenses can adjust their focal length and light direction dynamically based on driving conditions, road conditions, and ambient lighting, allowing the headlamps to adapt rather than remain static while maintaining simple mounting.

Inventive Principle:

Principle #15Dynamics

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

Enables precise control of light radiation direction without the need for large actuators, allowing for smaller and more efficient lighting devices, even with multiple lamp modules, by using a piezoelectric element to adjust the lens unit's position based on voltage changes.

Implementation Method 1

a piezoelectric element attached to a support portion configured to be bendable and connected to the lens unit and configured to be changeable in length upon receiving of electricity to cause the support portion to bend

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a lens unit provided in the housing to be changeable in position thereof and configured to concentrate light generated from the light source

Methodology Applied

Scientific EffectLight refraction and concentration: Lens

Data Source

PatentUS11326765B2Lighting device capable of controlling light radiation direction

Publication Date: 2022.05.10 HYUNDAI MOTOR CO LTD

AI summary

A lighting device configured for controlling a light radiation direction thereof, may include a housing provided with a light source; a lens unit provided in the housing, the lens unit being configured to concentrate the light generated from the light source; a length-variable unit mounted to the housing, the length-variable unit being configured so that a length thereof is changed, in a response to application of electricity thereto, in a direction in which the position of the lens unit is changed; and a controller configured to control a light radiation direction of the lens unit by setting a voltage of the electricity to be applied to the length-variable unit so that a length of the length-variable unit is changed according to a set voltage and the position of the lens unit is changed according to a change in the length of the length-variable unit.