Stereoscopic 3D Linear Polarization Brightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stereoscopic 3D projection systems using passive circular polarized viewing-glasses suffer from significant reduction in on-screen image brightness due to the absorption of light by linear polarizers, leading to severely lacking image brightness.
Innovation Solution
A polarization conversion system utilizing passive linear polarized viewing-glasses with a half-wave plate and pi-cell liquid crystal elements, where the half-wave plate compensates for the optical retardation in the pi-cell liquid crystal elements, allowing for high brightness and low cross-talk stereoscopic 3D images by optimizing the polarization states of the image beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If passive circular polarized viewing-glasses are used with linear polarizers, then stereoscopic 3D images can be displayed, but on-screen image brightness is significantly reduced
Solution Approach 1:
The patent changes the polarization state parameter from circular to linear by modifying the optical path. A half-wave plate is inserted in the optical path to convert circularly polarized light from the projector into linearly polarized light before it reaches the screen. This parameter change eliminates the need for linear polarizers in the viewing glasses, thereby eliminating light absorption losses and significantly improving on-screen brightness while maintaining stereoscopic 3D functionality
Solution Approach 2:
The half-wave plate serves as an intermediary optical element that mediates between the circularly polarized light source (projector) and the linearly polarized light requirement for the viewing system. By introducing this intermediary component, the system transforms the light polarization state without requiring energy-absorbing linear polarizers in the viewing path, thus preserving brightness
2Reliability
If linear polarizers are used in viewing-glasses, then polarization filtering is achieved, but cross-talk or ghosting increases
Solution Approach 1:
Instead of using linear polarizers to filter light (which causes cross-talk), the patent inverts the approach by using a half-wave plate to convert the projector's circular polarization into linear polarization. This inversion eliminates the need for filtering and thereby eliminates the cross-talk problem associated with linear polarizer-based systems
Solution Approach 2:
The patent extracts and removes the linear polarizers from the viewing-glasses system entirely. By taking out the problematic linear polarizing filters and replacing them with a half-wave plate conversion system, the harmful cross-talk effect is eliminated while maintaining the necessary polarization differentiation for stereoscopic viewing
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 achieves high on-screen image brightness and low cross-talk or ghosting, enabling effective viewing of time-multiplexed stereoscopic 3D images with improved optical contrast.
Implementation Method 1
the half-wave plate compensates for the optical retardation in the pi-cell liquid crystal elements, allowing for high brightness and low cross-talk stereoscopic 3D images by optimizing the polarization states of the image beams
Implementation Method 2
said polarization modulator may comprise at least one or more liquid crystal elements stacked together in order to achieve the required electro-optical switching characteristics
Implementation Method 3
the liquid crystal materials composing said pi-cell liquid crystal element form a helical structure between said substrates with an overall twist of 180 degrees
Data Source
AI summary
Stereoscopic 3D systems include a conversion system having a polarization beam-splitting element to separate a randomly polarized incident image-beam into one transmitted image-beam and at least one reflected image-beam, first and second polarization modulators arranged to modulate states of the transmitted and reflected image-beams between first and second output linear polarization states, the modulators including first and second pi-cell liquid crystal elements aligned in mutually crossed orientation and switched between first and second optical-states, one of the optical-states having in-plane optical retardation corresponding to a quarter-wave plate (QWP), an additional QWP proximate to one of the pi-cell liquid crystal elements and perpendicularly aligned to the optical axis for the in-plane optical retardation for one of the pi-cell liquid crystal elements. Passive linear polarized viewing-glasses include first and second lenses, each having a mutually parallel linear polarizer, and a half-wave plate located proximate the input surface for one of the lenses.