Projector Screen With Inclined Reflectors for Bright-Room Contrast
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Solution Overview
Problem
Projector screens for short throw projectors face issues with high manufacturing costs and reduced contrast ratio due to the formation of reflective surfaces through sputtering or coating, leading to increased black level and reduced bright-room contrast ratio.
Innovation Solution
A projector screen design featuring a light absorbing layer, inclined reflectors formed with white beads or resin, and a transparent layer with grooves, which reflects image light and absorbs external light, reducing the need for costly sputtering or coating processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If reflective surfaces are formed by sputtering or coating white ink on the lower inclined surfaces of protrusions, then image light reflection is achieved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive sputtering or coating processes with a low-cost alternative using white inkjet printing or adhesive application of white particles. This substitutes costly vacuum deposition or chemical coating with simpler, cheaper material application methods that achieve sufficient reflectivity without requiring high manufacturing precision
Solution Approach 2:
The patent changes the approach from forming precise reflective surfaces through controlled deposition (sputtering/coating) to using optically diffuse white materials applied through less precise methods. By changing from a precision-dependent process to a tolerance-friendly process, manufacturing cost is reduced while maintaining functional performance
2Manufacturing precision
If reflective surfaces are formed with insufficient precision, then manufacturing cost is reduced, but black level increases and bright-room contrast ratio deteriorates
Solution Approach 1:
The patent uses white inkjet printing or adhesive-bonded white particles instead of precision coating, accepting lower manufacturing precision in exchange for significantly reduced cost. The white material provides sufficient diffuse reflection to maintain contrast ratio without requiring the precision of sputtering
Solution Approach 2:
The patent changes from a precision-critical approach (where small variations in coating thickness affect performance) to a tolerance-friendly approach where the white material's diffuse reflective properties maintain performance across a wider range of manufacturing variations, thus preserving bright-room contrast ratio
3Ease of operation
If the screen structure uses protrusions with reflective surfaces, then image light is reflected toward the user, but external light from the ceiling is also reflected reducing contrast
Solution Approach 1:
The patent applies different optical properties to different regions: the upper inclined surfaces of protrusions have light-absorbing properties (black level optimization) while the lower inclined surfaces have light-reflecting properties (image light reflection). This spatial differentiation of optical qualities allows the screen to simultaneously reject ceiling light and reflect projector light effectively
Solution Approach 2:
Instead of making the entire surface reflective or using a single optical property, the patent inverts the approach by making the upper surfaces absorptive and the lower surfaces reflective. This inverted differentiation allows the screen to actively manage different light paths, preventing harmful ceiling light reflection while maintaining useful image light reflection
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 design improves the bright-room contrast ratio by effectively reflecting image light while absorbing external light, thereby enhancing image quality without increasing manufacturing costs.
Implementation Method 1
The absorption pattern layer 101 is formed to absorb external light G coming from the ceiling and not reflect it toward the user
Implementation Method 2
The plurality of reflective surfaces 103 are formed to reflect image light L emitted from the projector disposed below the projector screen 100 toward the user
Implementation Method 3
The transparent layer 105 is disposed in front of the absorption pattern layer 101 and the plurality of reflective surfaces 103 to form the front surface of the screen 100, and transmits external light G and image light L
Data Source
AI summary
A projector screen includes: a light absorbing layer configured to absorb light; a plurality of reflectors provided on a front surface of the light absorbing layer and spaced apart from each other at regular intervals, wherein the plurality of reflectors are inclined with respect to the light absorbing layer and are configured to reflect light; and a transparent layer disposed above the plurality of reflectors and configured to transmit light therethrough, wherein the transparent layer may include a front surface that is flat and parallel to the light absorbing layer, and a rear surface having a plurality of grooves having a shape corresponding to the plurality of reflectors, wherein the plurality of reflectors are provided in the plurality of grooves of the transparent layer, and the rear surface of the transparent layer contacts the front surface of the light absorbing layer.