Phosphor Wheel Dual-Side Emission for Projector Brightness

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Solution Overview

Problem

Conventional laser light sources for projectors face challenges in maximizing brightness due to absorption of fluorescent light by reflective layers and self-absorption within phosphor layers, leading to reduced luminous efficiency and light output.

Innovation Solution

The design omits the reflective layer in the phosphor wheel, allowing fluorescent light to emit from both sides, reducing absorption and increasing the light output ratio, and uses a phosphor wheel with different phosphor layers converting laser light at different timings to enhance luminous efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a reflective layer is used in the phosphor wheel to guide fluorescent light, then light direction control is improved, but light absorption increases and luminous efficiency decreases

Engineering Contradiction:
Improvebrightness of combined lightVSAvoidabsorption of fluorescent light
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent removes the reflective layer from the phosphor wheel structure. By extracting this component, the system eliminates the harmful absorption effect while still achieving light direction control through alternative means (phosphor layer arrangement and optical paths). This directly resolves the contradiction by eliminating the source of energy loss.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent utilizes both sides of the phosphor wheel to emit fluorescent light simultaneously. Instead of relying on a single emission side with reflective guidance, the system creates dual emission paths from the first and second sides of the phosphor wheel, effectively using dimensional expansion to improve light output without requiring reflective layers.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If a single phosphor layer is used in the phosphor wheel, then device complexity is reduced, but luminous efficiency and light output are limited

Engineering Contradiction:
Improveluminous efficiencyVSAvoidphosphor layer configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the phosphor wheel into multiple phosphor layers (first phosphor layer and second phosphor layer) with different characteristics. Each layer converts laser light to fluorescent light at different timings and wavelengths, creating a more efficient overall conversion system. This segmentation allows the system to achieve higher luminous efficiency by optimizing each layer's conversion characteristics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs sequential operation of different phosphor layers, where the first phosphor layer converts laser light to fluorescent light at a first timing, and the second phosphor layer converts laser light to fluorescent light at a second timing. This periodic action optimizes the overall light conversion efficiency by utilizing the temporal separation of conversion processes.

Inventive Principle:
Principle #19Periodic 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

This approach increases the brightness of the combined light emitted by 20% to 30% compared to conventional laser light sources by minimizing absorption and self-absorption, thereby improving luminous efficiency.

Implementation Method 1

The phosphor wheel receives the first laser light and converts the first laser light into the first fluorescent light and the second fluorescent light

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3364246B1Laser light source for projector and laser projection device
Publication Date: 2023.08.16 DELTA ELECTRONICS INC(CN)
  • EP3364246B1 patent drawingFigure 1
  • EP3364246B1 patent drawingFigure 2~5
  • EP3364246B1 patent drawingFigure 6~9

AI summary

A laser light source for projector includes a laser light source module, first and second light receiving modules, a phosphor wheel, and a light combining module. The phosphor wheel has a first and a second side. The phosphor wheel receives the laser and converts the laser into first and second fluorescent light. The phosphor wheel receives the laser at a first side and emits the first fluorescent light. The phosphor wheel emits the second fluorescent light at a second side. After the first fluorescent light and the second fluorescent light passes through the first and second light receiving modules, at least one of the directions of optical axes of the first and second fluorescent light is changed. The light combining module receives the first and second fluorescent lights and emits a combined light.