Aspheric Lens Light Source Device Placement Accuracy

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Solution Overview

Problem

Current projector light source configurations face challenges in accurately combining light from multiple LD arrays due to placement accuracy issues, leading to increased lens thickness and weight, which reduces light efficiency and increases absorption, resulting in lower luminance and higher weight of the projector.

Innovation Solution

A light source device with a holding member and energizing member that accurately positions the light combining member and condensing lens within the light source casing, using aspheric lenses to reduce thickness and weight, and a light combining device that combines light from multiple directions, ensuring proper alignment and sealing to enhance light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spherical lens is used to condense and parallelize the laser beam, then the lens can effectively process the luminous flux, but the thickness and weight of the lens increase, leading to increased weight of the light source section

Engineering Contradiction:
Improvelight condensing efficiencyVSAvoidweight of light source section
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the lens shape parameter from spherical to aspheric. The aspheric lens maintains the light condensing and parallelizing function while reducing the thickness dimension, particularly at the center part, which directly reduces the weight of the light source section without sacrificing optical performance

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the diameter of the luminous flux incident on the spherical lens increases due to increase in LD array size, then the light gathering capability is improved, but the thickness dimension of the lens increases, leading to increased weight

Engineering Contradiction:
Improveluminous flux diameterVSAvoidweight of light source section
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The aspheric lens design allows the lens to handle larger luminous flux diameters without proportionally increasing thickness. The aspheric surface profile optimizes light path control, enabling the lens to maintain effective light condensing capability while keeping the thickness dimension, especially at the center, significantly reduced compared to spherical lenses

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If multiple LD arrays are used to increase luminance, then the light output is improved, but the placement accuracy of each LD array and light combining member becomes critical, making assembly more difficult

Engineering Contradiction:
Improveprojected image luminanceVSAvoidplacement accuracy of components
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent divides the light source system into multiple independent LD arrays with separate optical paths, each having its own light combining member. This segmentation allows each component to be positioned and adjusted independently, reducing the cumulative placement accuracy requirements that would exist in a fully integrated system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light combining member acts as an intermediary component between each LD array and the final optical path. This intermediary allows for independent positioning and adjustment of each LD array while maintaining proper alignment through the light combining member, which facilitates easier assembly and reduces placement accuracy requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Improves placement accuracy of light combining components, reduces the thickness and weight of the light source device, enhances light efficiency by minimizing absorption, and increases the luminance of projected images while reducing the projector's overall weight.

Implementation Method 1

a luminous flux emitted from an LD array has a large diameter and is therefore condensed and parallelized by two lenses

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

As the lens situated on the light incident side of these lenses, a spherical lens is often employed. However, if such a spherical lens is employed, an increase in the diameter of the luminous flux incident on the spherical lens due to an increase in the size or the like of the LD array leads to the problem of increase in the thickness dimension

Methodology Applied
Scientific EffectAspheric lens optical property: Lens

Implementation Method 3

a configuration including a plurality of LD arrays and a light combining member combining light emitted from the plurality of LD arrays

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 4

The light source device includes: a first light source section having a first light emission area emitting light in a first direction; a second light source section having a second light emission area emitting light in a second direction different from the first direction; a light combining member combining light emitted from the first light emission area and light emitted from the second light emission area

Methodology Applied
Scientific EffectOptical path combination: Reflection

Data Source

PatentEP3407132B1Light source device and projector
Publication Date: 2022.05.04 SEIKO EPSON CORP
  • EP3407132B1 patent drawingFigure 1
  • EP3407132B1 patent drawingFigure 2
  • EP3407132B1 patent drawingFigure 3

AI summary

A light source device and a projector in which the placement accuracy of components can be improved are to be provided. A light source device includes: a first light source section and a second light source section which emit light along two different directions; a light combining member which combines the light emitted from the first light source section and the second light source section; a light source casing to which the first light source section and the second light source section are attached outside; and a holding member which holds the light combining member and is accommodated inside the light source casing. The holding member is fixed inside the light source casing.