Laser Projection Apparatus Polarization Alignment

Solution Overview

Problem

Current laser projection technologies face challenges in achieving high luminance and color balance due to differences in polarization directions of laser beams from red, blue, and green laser assemblies, leading to color cast phenomena and uneven chromaticity in projected images.

Innovation Solution

Incorporating half-wave plates in the laser paths of the blue and green laser assemblies to align their polarization directions with that of the red laser beam, ensuring all laser beams have the same polarization state before combination and projection, thereby eliminating color cast issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If laser beams from red, blue, and green laser assemblies are directly combined without polarization alignment, then the device structure is simple, but color cast phenomena occur and chromaticity uniformity deteriorates

Engineering Contradiction:

Improvedevice structureVSAvoidchromaticity uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

Half-wave plates are introduced as intermediary optical components in the laser paths of the blue and green laser assemblies. These half-wave plates act as mediators that rotate the polarization directions of the blue and green laser beams to align with the red laser beam's polarization direction, thereby eliminating color cast phenomena and achieving uniform chromaticity without significantly complicating the overall device structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The polarization direction parameter of the laser beams is changed by introducing half-wave plates. The half-wave plates rotate the polarization direction of the blue and green laser beams by 90 degrees each, transforming their polarization states to match the red laser beam. This parameter change resolves the chromaticity uniformity issue while maintaining relatively simple device architecture

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If half-wave plates are added to align polarization directions of blue and green laser beams, then chromaticity uniformity is improved, but device complexity increases

Engineering Contradiction:

Improvechromaticity uniformityVSAvoiddevice structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Half-wave plates are introduced as intermediary optical components in the laser paths of the blue and green laser assemblies. These half-wave plates act as mediators that rotate the polarization directions of the blue and green laser beams to align with the red laser beam's polarization direction, thereby eliminating color cast phenomena and achieving uniform chromaticity without significantly complicating the overall device structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The polarization direction parameter of the laser beams is changed by introducing half-wave plates. The half-wave plates rotate the polarization direction of the blue and green laser beams by 90 degrees each, transforming their polarization states to match the red laser beam. This parameter change resolves the chromaticity uniformity issue while maintaining relatively simple device architecture

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 solution ensures uniform chromaticity and high luminance in projected images by aligning polarization directions of all laser beams, effectively addressing the color cast and chromaticity imbalances caused by different polarization states of red, blue, and green beams.

Implementation Method 1

a first laser combining lens disposed at a position opposite to the third laser assembly, and configured to reflect the third laser beam

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

a second laser combining lens disposed at a junction of the second laser beam and the third laser beam, and configured to transmit the second laser beam and reflect the third laser beam

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 3

a third laser combining lens disposed at a junction of the first laser beam and both the second laser light and the third laser light propagating from the second laser combining lens, and configured to transmit the first laser beam and reflect the second laser beam and the third laser beam

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS11079665B2Laser projection apparatus

Publication Date: 2021.08.03 QINGDAO HISENSE LASER DISPLAY CO LTD

AI summary

The present disclosure describe embodiments of a laser projection apparatus. The apparatus includes: an apparatus housing, a laser source system, an optical illumination system and a lens system. The laser source system includes: a first laser assembly configured to emit a first laser beam, a second laser assembly configured to emit a second laser beam and a third laser assembly configured to emit a third laser beam; a first laser combining lens configured to reflect the third laser beam; a second laser combining lens configured to transmit the second laser beam and reflect the third laser beam; and a third laser combining lens configured to transmit the first laser beam and reflect the second and third laser beams. The optical illumination system is configured to modulate laser beams to generate a modulated beam. The lens system is configured to project the modulated beam onto a projection screen.