Color Separating System with Wavelength Selective Phase Plate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color separating/combining systems for liquid crystal projectors suffer from unnecessary light components that deteriorate image contrast due to imperfect polarization beam splitter (PBS) properties, allowing S-polarized light to pass through and P-polarized light to be reflected incorrectly.
Innovation Solution
A color separating/combining system is designed with a color separation element between the PBS and quarter-wave plates to guide blue light to the liquid crystal panel while suppressing red light, and using a combining prism to direct modulated light away from non-image light, enhancing the system's ability to project high-quality images by reducing unnecessary light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a polarization beam splitter (PBS) is used to separate color light components, then the color separation function is achieved, but unnecessary light components (S-polarized light passing through and P-polarized light being reflected incorrectly) deteriorate image contrast
Solution Approach 1:
A wavelength selective phase plate is introduced as an intermediary component between the PBS and the liquid crystal panel. This phase plate selectively affects different wavelength components (red, green, blue) by introducing wavelength-dependent phase shifts, enabling precise color separation while preventing unnecessary light components from reaching the projection optical system, thereby maintaining high image contrast
2Volume of moving object
If multiple liquid crystal panels are disposed at one polarization beam splitter to achieve size reduction, then device size is reduced, but the complexity of optical path management increases
Solution Approach 1:
Multiple liquid crystal panels (red, green, blue) are disposed at a single polarization beam splitter, merging the color separation function into one component. The wavelength selective phase plate further assists in directing different color components to their respective panels, simplifying the overall optical path management while achieving compact device size
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 reduces the impact of unnecessary light, improving image contrast and quality by optimizing the optical paths for red, green, and blue light, particularly in black display states, and maintaining high luminous efficiency.
Implementation Method 1
a first polarization element configured to guide one of the first color light and the second color light in a direction different from a direction of the other color light
Implementation Method 2
a first phase difference imparting portion... The first phase difference imparting portion and the first optical portion may be provided between the first light modulation element and the first polarization element
Data Source
AI summary
A color separating and/or combining system configured to guide blue (or first) light in a light beam from a light source to a blue-light (or first-light) liquid crystal panel and to guide red (or second) light to a red-light (or second-light) liquid crystal panel includes a PBS configured to guide one of the blue (or first) light and the red (or second) light in a direction different from a direction of the other color light, a quarter-wave plate, and a color separation element configured to guide the blue (or first) light to the blue-light (or first-light) liquid crystal panel and to suppress the red (or second) light from being guided to the blue-light (first-light) liquid crystal panel. The quarter-wave plate and the color separation element are provided between the blue-light (first-light) liquid crystal panel and the PBS. The color separation element is provided between the PBS and the quarter-wave plate.