Light Source Device Reflecting Member Light Loss
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Solution Overview
Problem
Existing light source devices for projectors suffer from light loss due to incomplete reflection of light by the reflective polarization element, leading to inefficiencies in light use.
Innovation Solution
A light source device configuration that includes a laser light source, a phosphor, a light guide with a taper shape, a reflective polarization element, and a reflecting member positioned to capture and reuse light that would otherwise be lost, utilizing a low refractive index layer and strategically placing the reflecting member to enhance light reflection and polarization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a reflective polarization element is used to transmit only predetermined polarization component, then light use efficiency is enhanced, but a part of reflected light fails to be totally reflected by the light guide inner surface and is emitted to the outside causing light loss
Solution Approach 1:
A reflecting member is introduced as an intermediary component positioned opposite to the light guide's side surface to capture light that would otherwise be emitted to the outside, and redirect it back into the light guide for reuse
Solution Approach 2:
The light guide is designed with a specific refractive index (greater than 1.4) and the reflecting member is positioned at a specific distance (0.5mm to 2.0mm) from the light guide surface to optimize light reflection and minimize light loss
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
The configuration significantly reduces light loss by reusing reflected light and ensuring efficient polarization, resulting in improved light use efficiency and uniform illuminance distribution.
Implementation Method 1
a light source section configured to emit excitation light
Implementation Method 2
a phosphor excited by the excitation light to emit fluorescence
Implementation Method 3
a light guide having a light incidence surface, a light exit surface and a side surface crossing the light incidence surface and the light exit surface, and configured to propagate the light entered an inside of the light guide
Implementation Method 4
a reflective polarization element disposed so as to be opposed to the light exit surface of the light guide, and configured to reflect first polarized light with a first polarization direction out of the fluorescence emitted from the light exit surface, and transmit second polarized light with a second polarization direction different from the first polarization direction
Implementation Method 5
a reflecting member disposed so as to be opposed to at least a part of the side surface of the light guide
Data Source
AI summary
A light source device includes a light source section that emits excitation light, a phosphor that emits fluorescence, a light guide having a light incidence surface, a light exit surface and a side surface crossing the light incidence surface and the light exit surface, and configured to propagate light entered an inside of the light guide, a reflective polarization element disposed to be opposed to the light exit surface, and configured to reflect first polarized light with a first polarization direction out of the fluorescence emitted from the light exit surface, and transmit second polarized light with a second polarization direction different from the first polarization direction out of the fluorescence emitted from the light exit surface, and a reflecting member disposed to be opposed to a part of the side surface of the light guide, wherein the phosphor is disposed at a position opposed to the light incidence surface.