Integrated Laser Light Source Device for Compact Projectors

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Solution Overview

Problem

Existing projector technologies face challenges in achieving color balance and reducing size due to differences in light emission efficiency among red, green, and blue laser light sources, leading to color unevenness and increased device size when trying to combine multiple laser light sources for white balance.

Innovation Solution

A compact light source device configuration where the center axes of red, green, and blue light sources coincide, using a holding member to support semiconductor lasers, and employing polarization separation and diffusion elements to minimize color unevenness and device size, allowing for a smaller projector with reduced color discrepancies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If multiple laser light sources of different colors are collectively disposed in one part to reduce device size, then the light source device size is reduced, but color unevenness occurs in the displayed image due to misaligned center axes

Engineering Contradiction:
Improvelight source device sizeVSAvoidcolor uniformity
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent combines multiple laser light sources (red, green, blue) and wavelength conversion elements (phosphors) into a single integrated light source device with a common excitation region, allowing them to share the same center axis and thereby maintaining color uniformity while reducing overall device size

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a wavelength conversion element (phosphor) as an intermediary that converts blue laser light into green or yellow-green light, enabling multiple colors to be generated from a single blue laser source and eliminating the need for separate green laser sources, thus improving axial alignment and color uniformity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If separately disposed red, green, and blue laser light source sections are combined with dichroic prisms to achieve white balance, then color balance is improved, but the light source device size increases

Engineering Contradiction:
Improvecolor balanceVSAvoidlight source device size
Core Design Contradiction:
Manufacturing precisionVSVolume of moving object

Solution Approach 1:

The patent merges multiple light source functions into a single integrated device where blue, green, and yellow-green light sources share a common excitation region and center axis, eliminating the need for separate light source sections and dichroic prisms, thus achieving color balance with a compact design

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The blue laser light source serves multiple functions by directly exciting different phosphor materials to generate both green and yellow-green light, as well as providing blue light, thereby replacing multiple separate light source sections with a single multi-functional source

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 configuration enhances color balance and reduces projector size by ensuring the center axes of different colored lights align, resulting in improved color uniformity and a more compact illumination device suitable for projectors.

Implementation Method 1

an illumination optical system that irradiates blue laser light on a phosphor to thereby cause the phosphor to emit green fluorescent light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

irradiates blue laser light on a phosphor to thereby cause the phosphor to emit green fluorescent light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP3435153B1Light source device, illumination device, and projector
Publication Date: 2022.02.23 SEIKO EPSON CORP
  • EP3435153B1 patent drawingFigure 1
  • EP3435153B1 patent drawingFigure 2~3
  • EP3435153B1 patent drawingFigure 4~5

AI summary

A light source device includes at least one first light emitting device configured to emit first light of a first color in a first direction and a plurality of second light emitting devices configured to emit second light of a second color different from the first color in the first direction. The number of the plurality of second light emitting devices is larger than the number of the at least one first light emitting device. The plurality of second light emitting devices are substantially rotationally symmetrically provided around the center axis of a first light in a peripheral region of the at least one first light emitting device.