Polarization Light Source Device for Compact Projector Cooling

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Solution Overview

Problem

Miniaturization of projectors is hindered by the need to reduce light-source intervals, which compromises cooling performance and increases the size of light ray composition units, as existing techniques struggle to efficiently combine light from multiple sources while maintaining heat dissipation.

Innovation Solution

A light source device comprising a first and second light source unit, a polarization beam splitter, and a polarization conversion element, where the first light source unit emits linear polarization light in one direction, and the second light source unit emits it in an opposite direction, with the polarization beam splitter reflecting and converting light to achieve high-intensity, compact light flux combination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the light-source interval is narrowed to miniaturize the optical system, then the size of the optical system is reduced, but the cooling performance is lowered and heat radiation becomes insufficient

Engineering Contradiction:

Improveoptical system sizeVSAvoidheat radiation performance

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The patent combines light fluxes from multiple light source arrays arranged in different spatial dimensions (first direction and second direction) into a single optical path. By utilizing polarization beam splitters and polarization conversion elements, light from light sources positioned at different locations and orientations is merged, enabling compact arrangement while maintaining effective heat dissipation paths for each light source.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If light from multiple light sources is combined using a reflective member such as a mirror, then light flux combination is achieved, but the light ray composition unit increases in size

Engineering Contradiction:

Improvelight flux combinationVSAvoidlight ray composition unit size

Core Design Contradiction:

Illumination intensityVSVolume of moving object

Solution Approach 1:

The patent replaces traditional reflective mirror-based light combination mechanisms with a polarization-based optical system. By using polarization beam splitters and polarization conversion elements, the system achieves light flux combination through polarization state manipulation rather than mechanical reflection, resulting in a more compact light ray composition unit.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes changes in polarization parameters to control light flux combination. By converting linear polarization light to circular polarization light and using polarization beam splitters to separate and recombine light fluxes based on polarization states, the system achieves efficient light combination in a compact configuration without requiring large reflective optical components.

Inventive Principle:

Principle #35Parameter changes

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 allows for high-intensity light flux combination while downsizing the projector, reducing the light flux diameter and enabling miniaturization of the illumination optical system, thereby addressing the cooling performance issues associated with reduced light-source intervals.

Implementation Method 1

The first polarization beam splitter is disposed between the first light source unit and the second light source unit, reflects the first linear polarization light, and transmits second linear polarization light of which polarization direction is perpendicular to the first linear polarization light

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 2

The polarization conversion element is configured with a transparent substrate having one surface with a 1⁄4 wavelength coat and another surface with a reflective coat. The first linear polarization light emitted from the second light source unit is converted into the second linear polarization light by the polarization conversion element

Methodology Applied

Scientific Effect1/4 wavelength coat conversion: Polarisation

Implementation Method 3

another surface with a reflective coat... is reflected in the third direction

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS10690931B2Light source device and projection display apparatus

Publication Date: 2020.06.23 PANASONIC PROJECTOR & DISPLAY CORPORATION

AI summary

A light source device includes first and second light source units, a first polarization beam splitter, and a polarization conversion element. The first light source unit emits first linear polarization light in a first direction. The second light source unit is disposed facing the first light source unit, and emits the first linear polarization light in a second direction opposite to the first direction. The first linear polarization light emitted from the first light source unit is reflected by the first polarization beam splitter in a third direction perpendicular to the first and second directions. The first linear polarization light emitted from the second light source unit is reflected by the first polarization beam splitter in a fourth direction opposite to the third direction, is converted into the second linear polarization light by the polarization conversion element, and is reflected in the third direction.