Light Recycling System for Projection Brightness

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Solution Overview

Problem

In projection systems using spatial light modulators, non-projection light is not efficiently utilized, leading to loss and absorption within the projector housing, rather than being recycled for further use.

Innovation Solution

A projection system comprising a light source, spatial light modulator, light recycling system, and lens assembly, where the light recycling system collects and redirects non-projection light back to the spatial light modulator for modulation, enhancing the brightness of the projection image by reusing off-state light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If non-projection light is absorbed by the housing or reflected back and forth inside the housing, then the structure is simple, but light energy is lost and not efficiently utilized

Engineering Contradiction:
Improvelight energy lossVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent recovers non-projection light (off-state light) that would otherwise be discarded and absorbed by the housing. A light recycling system captures this light and redirects it back to the spatial light modulator, allowing it to be reused for projection purposes, thereby reducing energy loss without requiring complete system redesign

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The patent introduces a light recycling system as an intermediary component between the spatial light modulator and the housing. This system includes light redirecting elements that intercept non-projection light and guide it back into the projection optical path, effectively mediating the recovery and reuse of otherwise lost light energy

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If non-projection light is reflected back and forth inside the housing, then no additional components are needed, but the light is eventually absorbed and not efficiently utilized

Engineering Contradiction:
Improvelight utilization efficiencyVSAvoidoptical system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The light recycling system acts as an intermediary that intercepts non-projection light before it is absorbed by the housing and redirects it back to the spatial light modulator. This mediator component enables efficient light reuse by providing a controlled optical path that prevents energy loss while maintaining system manageability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements continuous light recycling where non-projection light is constantly captured and redirected back to the spatial light modulator throughout the modulation period. This continuous recovery process ensures that light energy is repeatedly utilized for projection rather than being lost in discrete absorption events

Inventive Principle:
Principle #20Continuity of useful action

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 system effectively recycles non-projection light, increasing the brightness of the projection image and reducing the occurrence of overly bright images, particularly in scenarios with insufficient red light brightness.

Implementation Method 1

The spatial light modulator is configured to modulate, according to an image signal, light incident on the spatial light modulator to form projection light and non-projection light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the light recycling system is configured to receive at least a portion of the non-projection light and guide the at least a portion of the non-projection light toward the spatial light modulator

Methodology Applied
Scientific EffectLight guidance: Reflection

Data Source

PatentEP3467583B1Projection system
Publication Date: 2023.11.22 APPOTRONICS CORP LTD
  • EP3467583B1 patent drawingFigure 1
  • EP3467583B1 patent drawingFigure 2
  • EP3467583B1 patent drawingFigure 3

AI summary

A projection system (100), comprising: a light source (10), a spatial light modulator (40), a light recycling system (30, 60, 70), and a lens assembly (50). The light source (10) is used to emit source light toward the spatial light modulator (40). The spatial light modulator (40) is used to modulate, according to an image signal, light incident on the spatial light modulator (40), so as to form projection light and non-projection light. The light recycling system (30, 60, 70) is used to receive at least a portion of the non-projection light, and guide the at least a portion of the non-projection light toward the spatial light modulator (40). The lens assembly (50) is used to receive and emit the projection light to form a projection image. The projection system (100) of the present invention enables efficient use of non-projection light.