Synchronization Control Apparatus for Interlaced Scan Jitter
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Solution Overview
Problem
Interlaced scan signals in monitors result in a one-scan-line time difference between odd and even fields, leading to incompatibility issues and vertical jittering in image display due to unequal pulse intervals, which existing technologies fail to synchronize effectively.
Innovation Solution
A synchronization control apparatus and method that includes a delay circuit to generate a delayed vertical sync signal and a multiplexer to select between the original and delayed signals based on an odd/even field indication, ensuring equal pulse intervals for both fields, thereby generating a synchronized output vertical sync signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the OVS signal is controlled to be synchronous with the IVS signal to achieve normal video display without excessive memory buffering, then memory usage is reduced, but the pulse interval difference between odd and even fields propagates from input to output causing display incompatibility
Solution Approach 1:
The patent applies dynamics by making the delay amount adjustable based on field type. The synchronization control circuit dynamically changes the delay applied to even field VS signals (one scan line delay) versus odd field VS signals (no delay), allowing the system to adapt to the interlaced scan structure and eliminate pulse interval differences without requiring excessive memory buffering
Solution Approach 2:
The patent changes the time delay parameter selectively for even field VS signals. By introducing a one scan line delay specifically for even fields while maintaining odd fields unchanged, the patent equalizes the pulse intervals of both fields at the output, resolving the display compatibility issue while maintaining efficient memory usage
2Device complexity
If video processing operations are performed with odd and even field data in the same way, then processing is simplified, but vertical jittering is introduced to the images
Solution Approach 1:
The patent applies local quality by treating odd and even field VS signals differently based on their specific characteristics. The synchronization control circuit identifies the field type and applies different delay operations: no delay for odd fields and one scan line delay for even fields. This localized differentiation eliminates vertical jittering while keeping the overall processing framework simple
Data Source
AI summary
A synchronization control apparatus for driving a display module in an interlacing scan mode includes: a delay circuit for delaying an input vertical sync (IVS) signal to generate a delayed signal; and a multiplexer coupled to the delay circuit for selecting one of the IVS signal and the delayed signal according to an odd/even field indication signal to generate an output vertical sync (OVS) signal.