Continuous Tone Filter for Multichannel Projector Light Leakage
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Solution Overview
Problem
Conventional projection systems using multiple projectors face challenges in achieving true black images due to light leakage and contrast ratio limitations, particularly in display systems with misaligned projectors or overlapping images, which result in artifacts like double black zones and reduced image quality.
Innovation Solution
A continuous tone filter is created using a printer that can print on transparent substrates like glass, employing light-resistant inks or toners to achieve seamless image blending without the need for multiple masks, utilizing inkjet printing to produce a filter with varying optical densities and ensuring thermal and light resistance, thus avoiding dither patterns that cause diffraction and image distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple projectors are used to project images onto a display screen, then the image coverage and brightness are improved, but light leakage occurs in the black state and contrast ratio is reduced
Solution Approach 1:
An optical filter is introduced as an intermediary component between the projector and the display screen. This filter selectively blocks light in the black state while allowing image light to pass through, thereby eliminating light leakage and improving contrast ratio without affecting image brightness
Solution Approach 2:
The optical filter is designed with spatially varying optical densities, where different regions of the filter have different light transmission characteristics. This allows the filter to selectively block light in specific areas (such as the overlap region between multiple projectors) while maintaining transparency in other areas, thereby improving contrast ratio locally without compromising overall image quality
2Stability of the object's composition
If electronic compensation is used to reduce brightness in the overlap zone, then brightness uniformity is improved, but dark images cannot be adjusted since pixels are already at minimum value
Solution Approach 1:
The optical filter serves as a physical intermediary that can be adjusted independently of the projector's electronic systems. By changing the filter's position, optical density, or transmission characteristics, brightness uniformity can be achieved in the overlap zone without being constrained by the projector's electronic pixel limitations, thereby enabling adjustment capability for dark images
3Reliability
If a binary optical mask is used to block light, then light leakage is reduced, but the transition zone between bright and dark images is non linear and brightness artifacts occur
Solution Approach 1:
The optical filter is designed with spatially varying optical densities, where different regions of the filter have different light transmission characteristics. This allows the filter to selectively block light in specific areas (such as the overlap region between multiple projectors) while maintaining transparency in other areas, thereby improving contrast ratio locally without compromising overall image quality
Solution Approach 2:
Instead of using a binary mask with abrupt transitions, the optical filter uses continuous variations in optical density to create smooth transitions between transparent and opaque regions. This continuous parameter change eliminates non-linear brightness transitions and reduces brightness artifacts while maintaining effective light leakage control
4Manufacturing precision
If dither patterns are used to achieve grey scales in optical filters, then grey level control is improved, but diffraction and visibility of the dither pattern occur
Solution Approach 1:
Instead of using dither patterns with discrete dot arrangements, the optical filter uses continuous tone variations with smooth gradient transitions. This continuous parameter change eliminates the sharp edges and periodic structures that cause diffraction, thereby improving grey level control without generating diffraction artifacts or image distortion
Solution Approach 2:
The optical filter uses variations in optical density rather than dither patterns to achieve grey scales. By controlling the concentration and distribution of light-absorbing materials continuously, the filter achieves smooth grey level transitions without the discrete dot structures that cause diffraction and pattern visibility
5Reliability
If the optical filter has high optical density to block light effectively, then contrast ratio is improved, but the filter becomes more susceptible to thermal and light damage
Solution Approach 1:
The optical filter is constructed using composite materials that combine high light-absorbing capability with high thermal and optical stability. By using materials such as neutral density filters with stable optical characteristics and heat-resistant substrates, the filter achieves high contrast ratio performance while maintaining thermal and light resistance
Solution Approach 2:
The optical filter uses materials with high optical density that are specifically designed to be resistant to thermal and optical degradation. By selecting materials with stable optical characteristics across a wide temperature range and high light intensity, the filter maintains its contrast ratio performance without becoming susceptible to thermal and light damage
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 solution enables a full-black image with improved contrast ratio and sharpness, maintaining image quality even under high light intensities and temperatures, with the filter providing a non-distorted image for an extended lifespan.
Implementation Method 1
A continuous tone filter is created using a printer that can print on transparent substrates like glass, employing light-resistant inks or toners to achieve seamless image blending
Implementation Method 2
utilizing inkjet printing to produce a filter with varying optical densities and ensuring thermal and light resistance
Implementation Method 3
employing light-resistant inks or toners to achieve seamless image blending without the need for multiple masks
Data Source
AI summary
The present invention relates in part to a print method for an arbitrary grey scale image on a transparent substrate such as glass. The present invention makes use of a printer that can print in continuous grey tones. The printed material should be transparent and resistant to the light which passes through it in a projection system. The present invention also provides a continuous grey scale filter made by a printing techniques using liquid inks or toners. Such a continuous grey scale filter can be used for blending multiple images in a multichannel projector system. The present invention also provides a multichannel projector system using the continuous grey scale filter.