Projector Optical Module Uniformizing Laser Light on Phosphor

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Solution Overview

Problem

Current projector optical systems using solid-state light sources and phosphor elements face issues with non-uniform light intensity and inefficient light utilization due to misalignment and inappropriate light spot design, leading to reduced phosphor excitation efficiency and increased production costs.

Innovation Solution

The optical system includes a solid-state light source module with collimator lenses, an optical module with integration rods and relay lenses to ensure uniform and shaped light incidence on a reflective phosphor element, minimizing temperature-related efficiency degradation and optimizing light spot size and shape for efficient light modulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If laser beams are converged by a lens onto a phosphor element, then light of different colors is generated, but the light intensity on the phosphor element becomes non-uniform due to misalignment

Engineering Contradiction:
Improvelight intensity uniformityVSAvoidalignment precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent introduces a beam shaping optical system as an intermediary component between the laser diodes and phosphor element. This optical system includes specific optical elements that reshape the laser beams to ensure uniform intensity distribution across the phosphor element surface, eliminating the need for precise alignment adjustments during manufacturing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If laser beams are precisely aligned to achieve uniform light intensity, then phosphor excitation efficiency is optimized, but production time and costs increase

Engineering Contradiction:
Improveproduction efficiencyVSAvoidalignment time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The beam shaping optical system is pre-designed and pre-assembled with fixed optical elements that automatically shape the laser beams into the required intensity distribution pattern. This preliminary configuration eliminates the need for time-consuming alignment adjustments during the production process, thereby improving productivity while maintaining optimal phosphor excitation efficiency.

Inventive Principle:
Principle #10Preliminary action

3Area of stationary object

If the light spot area on the phosphor element is increased to improve coverage, then the Etendue of emission light becomes larger than acceptable for the light modulator

Engineering Contradiction:
Improvelight spot areaVSAvoidlight loss
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The beam shaping optical system creates a light spot with non-uniform intensity distribution, concentrating the light energy in specific regions that match the optimal excitation area of the phosphor element. This local quality approach ensures that the light spot area is optimized for phosphor excitation while maintaining the Etendue within acceptable limits for the light modulator, thereby minimizing light loss.

Inventive Principle:
Principle #3Local quality

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 achieves uniform light distribution and optimal excitation efficiency of the phosphor element, reducing light loss and improving projector performance while simplifying the alignment process, thus enhancing the production efficiency and cost-effectiveness of projectors.

Implementation Method 1

a solid-state light source module with a plurality of laser diodes and collimator lenses

Methodology Applied
Scientific EffectCollimation: Lens

Implementation Method 2

an optical module with integration rods and relay lenses to ensure uniform and shaped light incidence

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

relay lenses to ensure uniform and shaped light incidence on a reflective phosphor element

Methodology Applied
Scientific EffectFocusing: Lens

Implementation Method 4

the phosphor element is excited to emit light beams of a specific color

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP3663850B1Optical light source system for a projector
Publication Date: 2021.05.05 DELTA ELECTRONICS INC(CN)
  • EP3663850B1 patent drawingFigure 1
  • EP3663850B1 patent drawingFigure 2
  • EP3663850B1 patent drawingFigure 3

AI summary

An optical system for a projector is provided, which includes a solid-state light source module, an optical module, a phosphor element and a light relay module which are disposed sequentially. The light source module can generate a first beam, while the optical module can relay and uniformize the first beam so that the first beam is uniformly incident on the phosphor element. The optical module also makes the light spot of the first beam incident on the phosphor element into a predetermined shape and area, so that the phosphor element will emit a second beam by an emitting area. The light relay module can receive a part of the second beam, and the part of the second beam has a solid angle. An Etendue defined by the solid angle and the emitting area may be identical to the Etendue of a light modulator of the projector.