Adaptive Optics for Video Projector Screen Flatness
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Solution Overview
Problem
High Dynamic Range (HDR) content projection is challenging for projector systems due to the monochromatic nature of projection screens, which can result in image distortions and poor convergence caused by screen imperfections and misalignment between the projector and screen.
Innovation Solution
An adaptive optics system that includes a redirection array with movable elements, such as lenses or MEMS, which adjusts based on surface anomalies detected by a camera, ensuring precise alignment and minimizing distortions by calibrating the projection to compensate for surface irregularities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a projector projects video onto a flat screen, then the image should be clear and well-focused, but screen imperfections and misalignment cause local areas to have poor convergence and focus
Solution Approach 1:
The patent applies adaptive optics technology that dynamically adjusts the optical path in real-time to compensate for screen imperfections and misalignment. The system uses deformable mirrors or adjustable lenses that can change their shape or position to correct focus and convergence issues in different local areas of the projected image, ensuring consistent image quality across the entire screen surface.
Solution Approach 2:
The system employs feedback mechanisms where sensors detect the actual position and focus quality of the projected image on the screen. This information is fed back to the control system, which then adjusts the adaptive optics elements to correct any deviations from the desired image quality, creating a closed-loop control system that maintains optimal focus and convergence.
2Measurement precision
If the screen surface is not perfectly flat or has subtle imperfections, then the viewing experience is compromised, but replacing the screen with a perfectly flat one is not always feasible
Solution Approach 1:
The patent introduces adaptive optics elements as an intermediary between the projector and the screen. These optical elements act as a mediator that corrects the optical path before light reaches the imperfect screen surface, compensating for screen irregularities without requiring replacement of the screen itself. This allows the system to work with various screen types while maintaining image sharpness.
Solution Approach 2:
The system changes optical parameters such as wavefront curvature, focal length, and beam direction dynamically to compensate for screen imperfections. By adjusting these optical parameters in real-time, the system adapts to different screen conditions and maintains optimal image sharpness across diverse screen surfaces.
3Measurement precision
If imprecise distancing and alignment occur between projector and screen, then image convergence is affected, but manual adjustment is time-consuming and may not achieve perfect alignment
Solution Approach 1:
The system uses feedback from position sensors and image quality sensors to automatically detect misalignment between the projector and screen. The control system processes this feedback information and automatically adjusts the projector position or the adaptive optics elements to correct alignment errors, eliminating the need for manual adjustment and achieving precise alignment quickly.
Solution Approach 2:
The adaptive optics system performs self-alignment by automatically detecting and correcting its own positioning errors relative to the screen. The system uses built-in sensors to monitor alignment status and autonomously adjusts optical elements to maintain optimal alignment, reducing or eliminating the need for external manual intervention.
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 projects HDR content by compensating for surface imperfections, maintaining image quality and convergence, even on non-uniform or slightly deformed screens, thereby enhancing the viewing experience.
Implementation Method 1
A method and apparatus for adaptive optics for a video projector includes receiving reflections of light from a surface against which video is to be projected
Implementation Method 2
receive reflections of light from a surface against which video is to be projected
Implementation Method 3
the reflections of light are reflections of laser light directed onto the surface from a laser on a pixel-by-pixel basis
Implementation Method 4
The redirection array can includes individually movable elements selected from the group consisting of: lenses, mirrors, micro electro-mechanical systems (MEMS) elements
Data Source
AI summary
A deformable lens, deformable micro-mirror array, or combination thereof adjusts an image projected onto a screen to modify that image to compensate for small imperfections in the flatness of the surface the video is being projected onto. Initial calibration can be performed to create a screen profile, that is then used to adjust the optics to compensate for the detected screen anomalies. An initial grid projected onto the screen may be used for this purpose, with a high resolution camera imaging the grid and the perpendicularity, straightness and sharpness of the grid lines then being assessed by a processor to calculate the necessary optical modifications to modify the projected image such that the grid lines are straightened and aligned. In another embodiment a scanning laser is used to assess screen flatness and uniformity with pixel level precision.