Multi-Camera Clock Zeroing for Precise Frame Synchronization

The patent replaces the software-based trigger control mechanism with a hardware-based synchronization system. A master clock generates timing signals that are distributed through hardware trigger lines to multiple cameras, eliminating the serial program execution delays inherent in software triggering. This hardware substitution maintains ease of implementation while dramatically improving synchronization precision through dedicated timing circuits and parallel signal distribution.

The patent implements preliminary clock synchronization before actual image capture. The master clock establishes a common time reference for all cameras in advance, and the system waits for all cameras to be ready before initiating the capture sequence. This preliminary synchronization action ensures that when triggering occurs, all cameras are already aligned to the same time base, eliminating timing skew issues while maintaining simple trigger initiation.

The patent designs the frequency division module to serve multiple functions: it divides the master clock frequency to generate appropriate trigger rates for different camera configurations, provides phase-locked timing signals for synchronization, and offers adjustable division ratios to adapt to varying frame rates. This multi-functional design achieves precise synchronization while minimizing the number of separate components needed, as the same module handles timing generation, frequency adjustment, and phase alignment.

The patent introduces a timing distribution unit as an intermediary between the master clock and individual camera triggers. This intermediary module receives the master clock signal, performs frequency division and phase alignment, then distributes synchronized trigger signals to multiple cameras through dedicated hardware lines. The timing distribution unit acts as a buffer that isolates the complex clock management from the simple camera trigger interfaces, achieving precise synchronization without requiring complex timing circuits at each camera.

The patent performs zero calibration of local clocks as a preliminary action before actual image acquisition begins. The system initializes all camera clocks to a common reference point (time zero) established by the master clock, ensuring that all time bases are aligned before the first image capture. This preliminary calibration step, while adding initial complexity, establishes a stable time reference that simplifies subsequent acquisition operations and ensures consistent synchronization throughout the imaging sequence.

The patent implements a feedback mechanism during the calibration process where the system monitors the timing alignment between master clock and local clocks, and automatically adjusts the frequency division ratios or phase offsets to achieve optimal synchronization. This closed-loop feedback calibration reduces manual intervention and complex manual adjustment procedures, achieving precise time base alignment through automated adjustment while keeping the overall process manageable.