Display Signal Switching with Vertical Blanking Synchronization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing display systems face synchronization continuity issues during video signal switching, leading to image distortion and low visual quality due to asynchronous vertical synchronization signals.

Innovation Solution

A circuit apparatus with an internal image data output circuit, input circuit, selection circuit, and control circuit that adjusts the frame rate of internal image data during a switching period and switches between internal and input image data in the vertical blanking period to maintain synchronization continuity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a switching circuit switches between asynchronous video signals, then signal switching capability is improved, but synchronization continuity deteriorates

Engineering Contradiction:
Improvesignal switching capabilityVSAvoidsynchronization continuity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary actions by adjusting the frame rate of the first video signal before switching occurs. The control circuit modifies the timing characteristics of the first video signal in advance, ensuring that its vertical blanking period will overlap with the second video signal's vertical blanking period when switching happens, thereby maintaining synchronization continuity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the frame rate of the first video signal based on the timing characteristics of the second video signal. The control circuit continuously monitors and modifies the timing parameters to achieve optimal overlap between vertical blanking periods, enabling adaptive synchronization maintenance during signal switching

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If video signals with different vertical synchronization timings are switched, then signal flexibility is improved, but image quality deteriorates

Engineering Contradiction:
Improvesignal flexibilityVSAvoidimage quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system changes the timing parameters of the first video signal by adjusting its frame rate. The control circuit modifies specific parameters such as horizontal and vertical blanking periods to create an overlap with the second video signal's blanking period, ensuring smooth transitions without image distortion or display artifacts

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4579648A1Circuit apparatus and display system
Publication Date: 2025.07.02 SEIKO EPSON CORP
  • EP4579648A1 patent drawingFigure 1
  • EP4579648A1 patent drawingFigure 2
  • EP4579648A1 patent drawingFigure 3

AI summary

A selection circuit selects any of internal image data or input image data and outputs selected image data. An output circuit outputs output image data based on the selected image data. A control circuit controls an internal image data output circuit to output the internal image data at a frame rate different from that of the input image data in a switching period from the internal image data to the input image data. The control circuit controls the selection circuit to switch from the internal image data to the input image data in an overlap period between a vertical blanking period of the internal image data and a vertical blanking period of the input image data.