Seam Optical Uniformity in Perforated Projection Screens
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Solution Overview
Problem
Front projection screens face challenges in maintaining optical uniformity due to seams and perforations, which can make the seam area appear non-uniform and visible, especially when the perforation pattern is interrupted by the seam, and this affects the acoustic transmission and manufacturing process.
Innovation Solution
The solution involves broadening the region of optical change at the seam by varying the perforation pattern, using matte black dots to absorb light, and texturing the backer to minimize reflectivity, ensuring a constant average optical loss and uniform appearance across the screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the screen is perforated with an array of holes for acoustic transmission, then acoustic transmission through the screen is improved, but the perforation pattern may be interrupted by the seam and become highly visible
Solution Approach 1:
The patent applies different treatments to different regions of the screen. Specifically, the seam area receives special treatment with tapered perforations and optical compensation features, while the rest of the screen maintains a uniform perforation pattern. This local differentiation allows the seam region to mask optical non-uniformities while preserving acoustic transmission throughout the entire screen.
Solution Approach 2:
The patent employs optical compensation techniques that involve modifying the visual appearance of the seam region. By adjusting the perceived optical properties (effectively 'color' in the broad sense of visual characteristics) through tapered perforation patterns and compensation features, the seam becomes visually blended with the surrounding screen area, making it imperceptible to the audience.
2Area of stationary object
If the screen is seamed together from multiple sheets to achieve the required size, then the screen can be manufactured, but the change in surface reflectivity across the seam and the gap between adjacent sheets create optical non-uniformities
Solution Approach 1:
The patent implements preliminary actions during the seaming process by pre-planning the perforation pattern around the seam location. The perforation pattern is designed to be gradually varied approaching the seam, and compensation features are pre-positioned to mask optical non-uniformities before the audience views the screen. This proactive approach prevents visible seams rather than attempting to correct them after formation.
Solution Approach 2:
The patent modifies physical parameters in the seam region, specifically varying the perforation pattern geometry (tapered perforations) and spacing. These parameter changes create a gradual transition zone that masks the abrupt changes in surface reflectivity and gap width at the seam, making the optical non-uniformities imperceptible while maintaining the structural integrity of the seamed construction.
3Object-affected harmful factors
If the perforation pattern is kept uniform across the screen, then the screen appearance is maintained, but the presence of perforations limits the techniques in which the screen may be seamed together
Solution Approach 1:
The patent applies different perforation patterns to different regions: a uniform pattern in the bulk of the screen for aesthetic consistency, and a gradually varied pattern in the seam region to facilitate manufacturing. This localized differentiation allows the use of conventional seaming techniques while maintaining overall appearance uniformity, as the transition zone is designed to mask the seam.
Solution Approach 2:
The patent segments the perforation pattern into distinct zones: a uniform zone covering most of the screen area, and a transition zone near the seam with gradually varied perforations. This segmentation allows each zone to be optimized for its specific function - the uniform zone for appearance and the transition zone for manufacturing feasibility - while the zones blend together to create an overall uniform appearance.
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 approach effectively masks the optical loss at the seam, making it imperceptible to the audience and improving the strength and ease of seam manufacturing while maintaining a uniform viewing experience.
Implementation Method 1
printing patterns over a region in which the optical loss may occur, and in which the patterns optically absorb at least some light
Implementation Method 2
The backer may include an adhesive with an embossed texture that may serve to substantially diffuse specular reflection
Data Source
AI summary
Methods to substantially reduce or eliminate optical non-uniformity across an interface may also substantially improve the strength and ease of seam manufacturing, including joining substrates. The methods may include managing optical non-uniformities at least by broadening a region over which a change in optical loss may occur and/or by maintaining a substantially constant average optical loss across an interface. The methods may also include forming a seam that substantially reduces the appearance of optical non-uniformities at the seam, which may include maintaining approximately constant average loss in the vicinity of the seam by substantially controlling reflectivity in the vicinity of the seam, in which substantially controlling reflectivity in the vicinity of the seam may include employing a backer treated to minimize optical reflectivity over a range of angles.