Wavelength Estimation for Semiconductor Laser HUDs

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Solution Overview

Problem

Existing wavelength measurement methods for light sources in HUDs are complex and inefficient, making accurate wavelength estimation and light emission control challenging, especially in dynamic environments with varying temperatures and light conditions.

Innovation Solution

A simplified method using temperature dependence and light reception data to estimate the wavelength of light emitted from semiconductor lasers, allowing for accurate adjustment of light emission amounts to maintain desired color and image quality, without the need for complex superheterodyne methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a typical wavelength measurement method (superheterodyne using optical band-pass filter) is introduced, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvewavelength measurement precisionVSAvoidsystem configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential measurement function from the complex superheterodyne system. Instead of using the full superheterodyne apparatus with optical band-pass filters, it isolates the core wavelength-to-intensity relationship and implements a simplified detection mechanism that achieves the same measurement objective with fewer components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified model or representation of the wavelength measurement process. By using a light-receiving element that directly converts optical wavelength information into electrical signals through intensity variation, it copies the essential measurement function without requiring the complex physical infrastructure of superheterodyne detection.

Inventive Principle:
Principle #26Copying

2Measurement precision

If accurate wavelength measurement is implemented using conventional methods, then measurement precision is improved, but the device size increases

Engineering Contradiction:
Improvewavelength estimation accuracyVSAvoiddevice volume
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent removes unnecessary voluminous components from the measurement system. By extracting only the essential wavelength-detection function and implementing it through a compact light-receiving element, it achieves accurate wavelength estimation without the bulk of conventional measurement apparatus.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical/optical measurement mechanisms (such as rotating filters, moving mirrors, or bulky optical paths) with an electronic detection approach. The light-receiving element directly converts optical information into electrical signals, eliminating the need for complex mechanical or optical components that would increase device volume.

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

3Measurement precision

If complex wavelength measurement systems are used, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvewavelength measurement accuracyVSAvoidoperation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent extracts the essential measurement function from complex operational procedures. By focusing on the direct relationship between light wavelength and detected intensity, it eliminates complicated measurement protocols, calibration sequences, and operational steps, making the system easier to operate while maintaining precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent enables the measurement system to automatically determine wavelength information without requiring complex user intervention. The light-receiving element self-adjusts and directly outputs wavelength data based on the intensity of received light, making the system easy to operate while maintaining high measurement accuracy.

Inventive Principle:
Principle #25Self-service

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 approach enables accurate and efficient wavelength estimation and light emission control, ensuring high-quality color reproduction in HUDs, even under dynamic conditions, with a simplified configuration that reduces system complexity and size constraints.

Implementation Method 1

a light-receiving element to receive the light

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

estimating a wavelength of light emitted from the light source based on an amount of light received by the light-receiving element

Methodology Applied
Scientific EffectTemperature dependence of wavelength:

Data Source

PatentEP3226555B1Wavelength estimation device, light-source device, image display apparatus, wavelength estimation method, and light-source control method
Publication Date: 2019.11.20 RICOH CO LTD
  • EP3226555B1 patent drawingFigure 1~2
  • EP3226555B1 patent drawingFigure 3
  • EP3226555B1 patent drawingFigure 4

AI summary

A wavelength estimation device (7000) including a light detector (117) to receive light emitted from a light source (110) and an estimation unit (700a). The estimation unit (700a) estimates a wavelength of the light based on an amount of light received by the light detector (117).