Light Emitting Module Temperature Estimation by Lighting Pattern

Solution Overview

Problem

It is challenging to estimate the temperature of each light emitting element in a light emitting module effectively due to varying temperature increases based on lighting patterns, making it difficult to manage temperatures within acceptable limits.

Innovation Solution

A method and system that determine the electric power needed for a light emitting module based on its lighting pattern, using a controller to calculate estimated temperatures of light emitting elements by correlating electric power with temperature distributions through a preliminary testing system, allowing for accurate temperature estimation without the need for extensive temperature sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature sensors are installed for each light emitting element to accurately measure temperature, then temperature measurement precision is improved, but device complexity and manufacturing cost increase significantly

Engineering Contradiction:

Improvetemperature measurement precisionVSAvoidmodule structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a copy of the thermal field distribution obtained from finite element analysis simulations to represent the actual temperature distribution. Instead of directly measuring temperatures with sensors, the system calculates a thermal parameter from electrical characteristics and uses the pre-computed thermal field copy to determine element temperatures, avoiding the need for physical temperature sensors at each element location.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/physical temperature measurement system (temperature sensors) with an electrical measurement system. By measuring electrical characteristics (voltage, current, or resistance) of the light emitting elements and using these to calculate thermal parameters, the system substitutes direct thermal measurement with electrical measurement and computational thermal analysis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If temperature sensors are installed for each light emitting element, then temperature measurement precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improvetemperature measurement precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent uses a copy of the thermal field distribution obtained from finite element analysis simulations to represent the actual temperature distribution. Instead of directly measuring temperatures with sensors, the system calculates a thermal parameter from electrical characteristics and uses the pre-computed thermal field copy to determine element temperatures, avoiding the need for physical temperature sensors at each element location.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/physical temperature measurement system (temperature sensors) with an electrical measurement system. By measuring electrical characteristics (voltage, current, or resistance) of the light emitting elements and using these to calculate thermal parameters, the system substitutes direct thermal measurement with electrical measurement and computational thermal analysis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If the lighting pattern is evaluated by continuously operating the light emitting module, then temperature estimation accuracy is improved, but productivity and time efficiency deteriorate

Engineering Contradiction:

Improvetemperature estimation accuracyVSAvoidlighting pattern preparation efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary finite element analysis simulations to compute the thermal field distribution for various lighting patterns before actual evaluation. The thermal field data is pre-calculated and stored for different lighting patterns, allowing rapid temperature estimation during actual operation without requiring continuous operation and measurement cycles, thus improving productivity while maintaining accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses a copy of the thermal field distribution obtained from finite element analysis simulations to represent the actual temperature distribution. Instead of directly measuring temperatures with sensors, the system calculates a thermal parameter from electrical characteristics and uses the pre-computed thermal field copy to determine element temperatures, avoiding the need for physical temperature sensors at each element location.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS20240399956A1Method for estimating temperature of light emitting module, light emitting module, and automotive unit

Publication Date: 2024.12.05 NICHIA CORP

AI summary

A method for estimating a temperature of a light emitting module having a plurality of light emitting elements is provided. The method includes based on a lighting pattern of the light emitting module, which represents an intensity of light emitted from each of the plurality of light emitting elements, determining an amount of electric power to be supplied to the light emitting module for obtaining the lighting pattern and based on the lighting pattern and the determined amount of electric power, calculating estimated temperatures of the plurality of light emitting elements that are operated in accordance with the lighting pattern.