Rolling Shutter Artifacts on a Moving Inspection Line
Rolling shutter inspection lines require pulsed strobe lighting within global overlap windows or native global shutter sensors to eliminate motion shear errors.
Row Readout Time
Temporal Duration
Duration required for an image sensor to transfer the electrical charges or digital values from a single horizontal line of pixels to the output circuitry. Fast imaging applications rely on a low row readout time to achieve high frame rates and minimize motion blur. It defines the temporal resolution of the sensor and limits the maximum number of lines that can be processed per second.
Electronic Latency
Sequential access to the pixel array introduces a delay between the capture of the top row and the bottom row of an image. This effect in row readout time is a primary cause of rolling shutter distortion in CMOS sensors. Reducing the time per row requires higher clock speeds and more power in the analog to digital converters.
Signal Integrity
Rapidly switching the readout electronics can generate electromagnetic interference that degrades the image quality. Maintaining a consistent row readout time is necessary for the downstream processing algorithms to correctly interpret the timing of each pixel. Noise reduction techniques such as correlated double sampling must be completed within this narrow window.
If the readout is too fast, the accuracy of the voltage measurement may decrease due to insufficient settling time.
Throughput Capacity
Parallel readout architectures use multiple output channels to handle the data from several rows simultaneously. This configuration effectively reduces the total row readout time for the entire frame. High resolution sensors depend on this parallelism to maintain real time performance in industrial inspection.