Projection Screen Vibration Control to Minimize Speckle
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Solution Overview
Problem
Existing screen vibration systems for reducing visual artifacts like speckle and screen surface texture features are costly due to the need for multiple vibrating sources and controllers, which can lead to standing waves and inefficient energy distribution, and are affected by temperature and humidity changes that alter screen vibration characteristics.
Innovation Solution
A screen vibration system with distributed vibrating sources, each receiving de-correlated drive signals to minimize standing waves, and a feedback system that adjusts vibration energy based on image content and environmental conditions to maintain optimal vibration displacement, using acoustical or electromagnetic energy to reduce visual artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multiple vibrating sources are used to vibrate the screen, then visual artifacts like speckle and screen surface texture features are reduced, but system cost and complexity increase
Solution Approach 1:
The screen is divided into multiple zones, each with its own vibrating source. This segmentation allows independent control of vibration in different regions, enabling effective reduction of visual artifacts across the entire screen while optimizing the number and placement of vibrators based on specific artifact locations
Solution Approach 2:
Different regions of the screen receive different vibration characteristics tailored to their specific artifact problems. For example, areas with severe speckle receive higher vibration amplitudes, while areas with minor surface texture issues receive lower amplitudes, optimizing overall performance while reducing total system complexity
2Object-affected harmful factors
If multiple vibrating sources are used to vibrate the screen, then visual artifacts are reduced, but standing waves and inefficient energy distribution occur
Solution Approach 1:
The vibration system dynamically adjusts the amplitude and frequency of each vibrating source based on real-time feedback from sensors detecting screen vibration levels and artifact reduction effectiveness. This dynamic control prevents standing waves by continuously adapting vibration parameters to match changing screen conditions and viewer positions
Solution Approach 2:
Sensors positioned at various locations on the screen provide feedback information about vibration amplitude and artifact visibility. This feedback is used to adjust the operation of vibrating sources in real-time, optimizing energy distribution and preventing standing wave formation while maintaining effective artifact reduction
3Reliability
If screen vibration characteristics are not adjusted for environmental changes, then temperature and humidity changes alter vibration characteristics, but system performance degrades
Solution Approach 1:
Environmental sensors detect temperature and humidity changes, and this information feeds back to the control system which adjusts vibration source parameters accordingly. This feedback mechanism maintains consistent vibration characteristics and artifact reduction performance despite varying environmental conditions
Solution Approach 2:
The system changes vibration parameters such as amplitude and frequency in response to environmental conditions. For example, higher amplitudes may be applied in humid conditions that increase screen damping, while frequency adjustments compensate for temperature-induced changes in screen material properties, maintaining reliable artifact reduction across environments
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 reduces the cost and complexity of screen vibration systems while effectively minimizing visual artifacts like speckle and screen texture features, maintaining optimal vibration displacement despite environmental changes, and improving the overall visual experience by distributing vibration energy efficiently across the screen.
Implementation Method 1
the system includes a screen, a permanent magnet mounted to the screen, and a magnetic source positioned with respect to the permanent magnet and uncoupled from the screen. The screen is moveable in response to a changing magnetic field from the magnetic source.
Implementation Method 2
When a high frequency, low voltage signal is applied to the liquid crystal projection display screen, the liquid crystal molecules vibrate slightly at a frequency higher than 60 Hz, thereby causing the speckle pattern to change quickly
Data Source
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AI summary
A screen can be vibrated by vibrators that are drivable by signals. Each vibrator can be adjacent in position to other vibrators that are drivable by different types of drive signals than a drive signal associated with the vibrator. The number of drive signals can be equal to or less than the number of vibrators. A vibrator assembly for a vibrator can include a baffle and a transducer that couples to the baffle. The transducer can vibrate at least a portion of the screen. The vibrating screen can be monitored by a sensor and an analyzer unit that can analyze image speckle and screen displacement artifacts in captured images of images projected onto the screen and output results of the analysis.