Multi-Display Playback Synchronization Using Master-Client Timing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electronic devices face playback time discrepancies when sharing content due to varying network latencies, necessitating a technology to synchronize video playback times across multiple devices.

Innovation Solution

A display system and method that determines whether a device operates as a master or client within a sync group, using multicast communication protocols to synchronize playback times based on master playback information, including presentation time stamps and buffering times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If content is shared between multiple electronic devices over a wireless network, then content sharing capability is improved, but playback time synchronization deteriorates due to varying network latencies

Engineering Contradiction:
Improvecontent sharing capabilityVSAvoidplayback time synchronization
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a sync group manager as an intermediary component that coordinates between multiple display devices. This manager receives sync group information from the host and distributes synchronization commands to client devices, acting as a mediator to compensate for network latency variations and maintain synchronized playback across devices

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback mechanisms where client devices continuously monitor their playback status and buffer states, reporting this information back to the sync group manager. The manager then adjusts synchronization commands based on this feedback, allowing dynamic adaptation to network conditions and maintaining synchronization despite varying latencies

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the system dynamically determines master and client devices based on sync group configuration changes, then adaptability to network changes is improved, but device complexity increases due to multicast protocol implementation

Engineering Contradiction:
Improveadaptability to sync group changesVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the system into distinct functional roles: host devices that generate content, a sync group manager that coordinates synchronization, and client devices that consume content. This segmentation allows each device type to have simplified, role-specific logic while the overall system maintains high adaptability through the manager's coordination capabilities

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts device roles (master/client) based on sync group configuration changes detected through multicast protocols. When devices join or leave the sync group, the manager dynamically reassigns roles and updates synchronization parameters, allowing the system to adapt to changing network conditions without requiring complex static configuration

Inventive Principle:
Principle #15Dynamics

3Reliability

If playback time synchronization is implemented across multiple devices, then playback synchronization is improved, but loss of time increases due to network latency variations

Engineering Contradiction:
Improveplayback time synchronizationVSAvoidnetwork latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by pre-synchronizing clock times between the sync group manager and client devices before content playback begins. It also pre-loads buffer data and establishes synchronization parameters in advance, so that when playback starts, devices are already aligned and can maintain synchronization despite subsequent network latency variations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements periodic synchronization actions where the sync group manager continuously sends time reference signals and synchronization commands at regular intervals during playback. This periodic reinforcement maintains synchronization alignment across devices, compensating for drift that accumulates over time due to network latency

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4697730A1Display system for output image synchronization, and display method using same
Publication Date: 2026.02.18 SAMSUNG ELECTRONICS CO LTD
  • EP4697730A1 patent drawingFigure 1
  • EP4697730A1 patent drawingFigure 2
  • EP4697730A1 patent drawingFigure 3

AI summary

A display system, according to the embodiments of the present disclosure, may comprise: a host; and at least one display device receiving an image reproduction signal from the host. The at least one display device may: recognize a sync group on the basis of the image reproduction signal; determine whether to operate as a master device or a client device in the sync group; and, on the basis of master reproduction information from the master device, synchronize the reproduction time of an output image between the at least one display device and at least one other display device.