Pulsed Illumination Synchronization for Global Reset Rolling Shutter Imagers
Global Reset rolling shutter imagers eliminate motion blur when pulsed light fires strictly within the dark global integration window under controlled ambient light.
Pulsed Illumination
Lighting Mode
A method of scene lighting that delivers brief bursts of optical energy rather than continuous light provides a way to freeze fast-moving objects in imaging applications. Using pulsed illumination allows sensors to capture clear frames with minimal motion blur even at low shutter speeds. This technique is often used in automated sorting and high-speed inspection tasks on production lines.
Motion Stiffening
The duration of the light pulse determines the effective exposure period of the image rather than the sensor shutter speed itself. By utilizing pulsed illumination, a system can achieve an effective exposure time in the microsecond range while keeping the electronic shutter open longer. This process reduces the need for ultra-fast sensor readout circuits and minimizes the impact of ambient light.
This approach is highly effective when the intensity of the light pulse is strong enough to dominate the total exposure.
Thermal Load
High peak currents in the light-emitting diodes produce excessive heat during rapid pulsing cycles. This thermal stress must be managed by heatsinks to prevent output degradation.
Synchronization Control
Precise timing between the light source and the sensor shutter is maintained using a dedicated digital controller. The light pulse must occur during the period when all pixel rows are open to prevent uneven exposure across the image. This timing is verified by measuring the delay between the sensor trigger output and the optical pulse rise time.