Phase Adjustment Circuit for Endoscope Video Sampling Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing endoscope systems face challenges in accurately capturing video signals due to phase differences between clock and sampling signals, leading to instability in signal capture timing, particularly when the video signal passes through cables, causing waveform deterioration and making it difficult to synchronize phases effectively.
Innovation Solution
A phase adjustment circuit is designed with a binary circuit, phase-delayed clock signal generation circuit, and sampling signal generation circuit to detect video signal edges, generate phase-delayed clock signals, and adjust sampling signals to match the phase of the clock signal, ensuring accurate timing for capturing video signals by introducing controlled delay amounts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the video signal is transmitted through cables, then the signal can be transferred from the camera unit to the AFE, but phase delay occurs between the clock signal and video signal, causing phase difference with the sampling signal
Solution Approach 1:
The phase adjustment circuit performs preliminary phase adjustment on the sampling signal based on the adjustment signal before the actual sampling operation. This preliminary action compensates for the phase delay caused by cable transmission, ensuring that the sampling signal is properly synchronized with the video signal before capturing the image data.
Solution Approach 2:
The system uses the adjustment signal generated by the processor as feedback to control the phase adjustment circuit. The adjustment signal is generated based on the clock signal and provides feedback control to compensate for phase delays, enabling dynamic phase synchronization between the sampling signal and video signal during operation.
2Measurement precision
If the phase adjustment circuit delays the sampling signal to synchronize with the video signal, then accurate timing is achieved, but the circuit complexity increases
Solution Approach 1:
The phase adjustment circuit acts as an intermediary component between the signal generation circuit and the ADC. It receives the sampling signal and adjustment signal, performs phase adjustment using delay circuits, and outputs the corrected sampling signal to the ADC, thereby isolating the complexity of phase synchronization from the main sampling path.
Solution Approach 2:
The phase adjustment circuit changes the phase parameter of the sampling signal by introducing controlled time delays through delay circuits. By adjusting the delay amount based on the adjustment signal, the circuit modifies the temporal parameter of the sampling signal to achieve synchronization without fundamentally changing the circuit architecture.
3Measurement precision
If the sampling signal phase is adjusted dynamically, then synchronization accuracy is improved, but the adjustment time and processing overhead increase
Solution Approach 1:
The phase adjustment circuit performs preliminary phase adjustment using the adjustment signal before the actual sampling operation begins. This preliminary action ensures that the phase synchronization is established in advance, reducing the need for time-consuming adjustments during the sampling process itself.
Solution Approach 2:
The system replaces complex mechanical or iterative phase adjustment mechanisms with an electronic signal-based adjustment approach. The adjustment signal electronically controls the delay circuits to achieve phase synchronization, which is faster and more efficient than mechanical adjustment methods, thereby reducing the time loss associated with phase adjustment.
Data Source
AI summary
In a phase adjustment circuit, a binary circuit is configured to output a binary signal on the basis of an edge of a video signal. A phase-delayed clock signal generation circuit is configured to generate a phase-delayed clock signal having a later phase than a phase of a clock signal by a first delay amount. A delay time control circuit is configured to cause a phase of the binary signal and the phase of the phase-delayed clock signal to match each other by adjusting the first delay amount. A sampling signal generation circuit is configured to generate a sampling signal having a later phase than the phase of the clock signal by a second delay amount. The second delay amount is in accordance with both a phase shift amount, which is based on the clock signal, and the first delay amount.