Projector Light-incident-side Polarizing Element Heat Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Single-panel projectors face issues with lens deformation and deterioration due to increased heat and light absorption, leading to decreased optical function and color accuracy, particularly with lenses closer to the light source.

Innovation Solution

A projector design that includes a light source, a wavelength converter, an optical system for enlarging luminous flux, a parallelizing lens, a light modulator, a light-exiting-side polarizing element, and a light-incident-side polarizing element positioned between the light source and the parallelizing lens, which transmits polarized light and reflects unpolarized light to reduce heat absorption and lens degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a reflective polarizing plate is provided between the light source and the liquid crystal panel, then the light utilization efficiency is improved, but the lens disposed closer to the light source absorbs more heat and degrades

Engineering Contradiction:
Improvelight utilization efficiencyVSAvoidlens durability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

A heat-absorbing member is introduced as an intermediary component between the light source and the lens. This mediator absorbs excess heat from the light source before the light reaches the lens, thereby protecting the lens from thermal degradation while maintaining the reflective polarizing plate's light utilization efficiency benefits

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful heat generated by the light source into a beneficial protective mechanism. By placing a heat-absorbing member that selectively absorbs harmful thermal radiation while allowing useful light to pass through, the harmful thermal energy is transformed into a protective barrier that prevents lens degradation

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Volume of moving object

If the lens is disposed closer to the light source to compact the structure, then the device size is reduced, but the lens deforms and deteriorates due to increased heat absorption

Engineering Contradiction:
Improveprojector sizeVSAvoidlens temperature
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The heat-absorbing member serves as a thermal mediator positioned between the light source and the lens. It selectively absorbs harmful thermal radiation while allowing useful light to pass through, thereby enabling the lens to be disposed closer to the light source for compact design without suffering from excessive heat exposure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Weight of moving object

If the lens material is made of resin for lightweight construction, then the weight is reduced, but the lens is more susceptible to yellowing and deterioration from heat and light

Engineering Contradiction:
Improvelens weightVSAvoidlens yellowing and deterioration
Core Design Contradiction:
Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The heat-absorbing member acts as a protective intermediary that filters out harmful thermal radiation and ultraviolet components before they reach the resin lens. This allows the use of lightweight resin materials without compromising the lens's resistance to yellowing and deterioration, as the harmful factors are blocked by the intermediary heat-absorbing layer

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

This configuration reduces lens degradation, maintains optical function, and enhances light utilization efficiency by directing polarized light effectively, preventing yellowing and ensuring better color balance and image quality.

Implementation Method 1

a light-incident-side polarizing element that transmits light polarized in a predetermined polarization direction and reflects light polarized in a direction other than the predetermined polarization direction

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

a wavelength converter that is irradiated with the first light and emits second light emitted at a wavelength different from the wavelength at which the first light is emitted

Methodology Applied
Scientific EffectWavelength conversion: Fluorescence

Data Source

PatentEP4369095A1projector
Publication Date: 2024.05.15 SEIKO EPSON CORP
  • EP4369095A1 patent drawingFigure 1
  • EP4369095A1 patent drawingFigure 2
  • EP4369095A1 patent drawingFigure 3~4

AI summary

A projector according to an aspect of the present disclosure includes a light source that emits first light, a wavelength converter that is irradiated with the first light and emits second light emitted at a wavelength different from the wavelength at which the first light is emitted, an optical system that enlarges the luminous flux of the first light and the luminous flux of the second light from the wavelength converter, a parallelizing lens, a light modulator, a light-exiting-side polarizing element, a projection lens, and a light-incident-side polarizing element that transmits light polarized in a predetermined polarization direction and reflects light polarized in a direction other than the predetermined polarization direction. Nonlinearly polarized light enters the light-incident-side polarizing element, and the light-incident-side polarizing element is disposed on the optical path of the second light between the light source and the parallelizing lens.