Vehicle Lighting Device Using Differential Thermal Expansion Films

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Solution Overview

Problem

Conventional vehicle interior mood lighting lacks dynamic design options, limiting its aesthetic appeal and merchantability due to fixed optical patterns and color changes, which restricts its design flexibility and market appeal.

Innovation Solution

A lighting device using two or more films with different thermal expansion coefficients, allowing light to be projected onto varying patterns without a separate drive device, utilizing temperature changes to dynamically alter the moire pattern displayed, and optionally incorporating bimetals for enhanced displacement variation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional mood lighting with fixed optical patterns is used, then the lighting structure is simple, but the design variability and aesthetic appeal are limited

Engineering Contradiction:

Improvedesign variabilityVSAvoidlighting structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs films with different thermal expansion coefficients that expand or contract at different rates in response to temperature changes, causing the moire pattern to dynamically change. This thermal-driven mechanism enables design variability without requiring complex drive devices, motors, or additional power consumption, thus resolving the contradiction between adaptability and device complexity

Inventive Principle:

Principle #37Thermal expansion

Solution Approach 2:

The lighting device utilizes the natural temperature changes occurring in the vehicle interior environment to drive the pattern changes. The system is self-powered, using ambient thermal energy rather than requiring separate drive devices or additional power sources, thereby achieving dynamic design variability while maintaining structural simplicity

Inventive Principle:

Principle #25Self-service

2Adaptability or versatility

If dynamic pattern changes are implemented using separate drive devices, then the design variability improves, but the device complexity and power consumption increase

Engineering Contradiction:

Improvepattern dynamicsVSAvoiddrive device complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

By selecting films with significantly different thermal expansion coefficients (difference ≥ 0.001 cm/cm·°C.), the patent creates a thermal actuation mechanism that produces visible moire pattern changes in response to vehicle interior temperature variations. This eliminates the need for motors, actuators, or control systems, achieving pattern dynamics without increasing device complexity

Inventive Principle:

Principle #37Thermal expansion

Solution Approach 2:

The patent replaces mechanical drive devices (motors, actuators, linkages) with a thermal-mechanical system based on differential thermal expansion. The thermal energy from the vehicle environment directly drives the pattern changes through the bimetallic film structure, substituting complex mechanical systems with a simpler thermal response mechanism

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If multiple films with different thermal expansion coefficients are used, then the pattern dynamics improve, but the manufacturing complexity increases

Engineering Contradiction:

Improvemoire pattern variabilityVSAvoidfilm assembly complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent divides the lighting structure into multiple film layers, each with specific thermal expansion properties and pattern characteristics. This segmentation allows independent selection and optimization of each film's properties while maintaining overall system functionality. The layered structure enables complex moire patterns to be created through simple stacking of individually manufacturable films

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses composite film structures combining materials with different thermal expansion coefficients to create the moire effect. These composite materials can be manufactured using existing film production techniques, and the assembly process leverages standard lamination or adhesive bonding methods, maintaining ease of manufacture while achieving pattern dynamics

Inventive Principle:

Principle #40Composite materials

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 dynamic pattern changes within the vehicle interior without additional power consumption or complexity, enhancing design variability, weight efficiency, and cost-effectiveness, thereby improving the merchantability of lighting systems and finished vehicles.

Implementation Method 1

thermal expansion coefficients of at least two films among the two or more films are different from each other

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

two or more films that allow light generated by the light source to be projected onto a particular shape depending on a pattern

Methodology Applied

Scientific EffectMoiré effect: Moiré Interferometry

Data Source

PatentUS10837614B2Lighting device for vehicle

Publication Date: 2020.11.17 HYUNDAI MOTOR CO LTD

AI summary

A lighting device for a vehicle may include: a light source for generating light by an applied power source; and two or more films that allow light generated by the light source to be projected onto a particular shape depending on a pattern. Thermal expansion coefficients of at least two films among the two or more films are different from each other.