Embedded Video Markers for Shutter Glasses Synchronization

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Solution Overview

Problem

Existing systems for controlling shutter glasses in stereoscopic image viewing are display-dependent and require modifications to existing hardware, limiting their use in standard displays, especially for live broadcast content like high-definition television at 60Hz.

Innovation Solution

A video data signal with embedded markers in each frame, detectable by photosensors, controls the shutter glasses by distinguishing between left-eye and right-eye frames based on graphical properties, allowing synchronization without modifying display hardware, ensuring proper shutter operation across various refresh rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an external shutter synchronizer is used to control LCD shutters based on computer output signals, then the alternately transparent rate of shutters can be synchronized with image display, but additional delays introduced by the display may desynchronize the shutters

Engineering Contradiction:
Improvesynchronization reliabilityVSAvoiddisplay delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent embeds synchronization markers at specific positions within video frames (e.g., at known time offsets such as 1/6th or 5/6th of frame duration) before the frames are displayed. This preliminary placement of markers allows the shutter control system to anticipate and compensate for display delays, ensuring that shutter transitions occur at the correct moments relative to the actual displayed content rather than relying on theoretical timing from the computer output.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If synchronization is based on assumed frame display timing, then the system can operate with standard displays, but the solution does not account for varying refresh rates and frame display times

Engineering Contradiction:
Improvedisplay compatibilityVSAvoidframe timing accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent incorporates feedback mechanisms where the shutter control system monitors the actual display timing by detecting synchronization markers in the displayed video signal. This feedback allows the system to measure and adapt to the actual refresh rate and frame display time of the specific display device being used, rather than relying on assumed or theoretical timing values. The system can dynamically adjust its shutter control timing based on the measured display characteristics.

Inventive Principle:
Principle #23Feedback

3Ease of manufacture

If markers are embedded in video frames to control shutter synchronization, then hardware modifications are avoided, but the markers must be distinguishable between left-eye and right-eye frames

Engineering Contradiction:
Improvehardware modification requirementVSAvoidmarker differentiation complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent uses color or luminance changes as the graphical property to differentiate between left-eye and right-eye frames. Specifically, markers in left-eye frames have one color or luminance level while markers in right-eye frames have a different color or luminance level. This allows photosensors to easily distinguish between the two types of frames by detecting the color or brightness difference, providing a simple and reliable method for shutter control without requiring complex marker designs.

Inventive Principle:
Principle #32Color changes

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 a three-dimensional viewing experience on standard displays without requiring hardware modifications, ensuring synchronization and reducing dependency on specific display types, making it suitable for live broadcasts and standard television sets.

Implementation Method 1

detectable by photosensors, controls the shutter glasses by distinguishing between left-eye and right-eye frames based on graphical properties

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

The whole concept is utilised in systems having means for alternately making right and left type shutter of the shutter glasses transparent. Typically the shutters are liquid-crystal-display (LCD) type shutters.

Methodology Applied
Scientific EffectLiquid Crystal Optical Properties: Liquid Crystals

Data Source

PatentEP2257076B1Video data signal, system and method for controlling shutter glasses
Publication Date: 2015.02.25 ADVANCED DIGITAL BROADCAST
  • EP2257076B1 patent drawingFigure 1A~1B
  • EP2257076B1 patent drawingFigure 2A
  • EP2257076B1 patent drawingFigure 3

AI summary

A signal, method, system and computer program product is based on displaying at least two markers embedded within each frame of the video content. One of the at least two markers is displayed in a first half of each video frame and a second of the at least two markers is displayed in a second half of each video frame, the frame being split into the first and the second halves along a splitting line being perpendicular to an axis that is a refresh axis for a particular display screen. The markers are such that enable distinguishing whether a right-eye or left-eye frame is displayed.