Interactive Touch Screen Camera Synchronization for Flicker-Free Video
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Solution Overview
Problem
Existing systems for video imaging and display on interactive touch screens fail to provide a seamless, eye-to-eye interaction experience, with users appearing to look off-camera in traditional teleconferencing setups, and struggle with flicker issues when capturing through polarized LCD screens.
Innovation Solution
An apparatus comprising a camera with controllable frame rate and exposure, a horizontally polarized screen, and an LCD screen, where the camera is positioned to capture through the screen without seeing the reverse image, and a micro-controller generates synchronized pulse width modulated signals to alternate the backlight and camera exposure, ensuring flicker-free display and eye-to-eye interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a camera captures video through a polarized LCD screen, then the display can be viewed through the screen, but flicker occurs during capture
Solution Approach 1:
The patent applies periodic action by synchronizing the camera exposure timing with the LCD screen refresh cycles. The camera captures frames at specific intervals that align with the screen's refresh rate, ensuring that the camera only captures stable display content rather than intermediate states that cause flicker. This timing synchronization eliminates the flicker effect while maintaining continuous display visibility.
2Ease of operation
If the camera is positioned to capture through the screen, then eye-to-eye interaction is achieved, but the reverse image becomes visible
Solution Approach 1:
The patent applies local quality by using a polarized screen with different optical properties in different regions or orientations. The polarization filter is configured to allow light from the camera to pass through to the display while blocking the reverse image from reaching the camera sensor. This selective optical filtering based on polarization direction eliminates the harmful reverse image while preserving the desired eye-to-eye interaction capability.
3Device complexity
If the backlight and camera exposure are unsynchronized, then simple operation is maintained, but flicker occurs in the display
Solution Approach 1:
The patent applies feedback by implementing a control system that monitors the LCD screen refresh rate and automatically adjusts the camera exposure timing accordingly. A sensor or controller detects the screen's operational state and provides feedback to synchronize the camera's frame capture timing. This closed-loop synchronization ensures flicker-free operation while maintaining relatively simple system architecture through automatic adaptation rather than complex manual configuration.
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
Enables simultaneous recording and projection of live video streams onto interactive touch screens, providing an eye-to-eye interaction experience without flicker, allowing users to see each other as if they are in normal conversation, while maintaining transparency and preserving size and perspective.
Implementation Method 1
a horizontally polarized screen associated with one face of the backlight panel
Implementation Method 2
a LCD screen
Data Source
AI summary
An apparatus for simultaneously recording a first live video stream and projecting a second live video stream onto an interactive touch screen, the apparatus comprising (a) a backlight panel; (b) a horizontally polarized screen associated with one face of the backlight panel; (c) a camera having a lens, the camera having controllable frame rate and exposure; and, (d) a LCD screen.