Time Delay Integration Cameras

TDI is based on the concept of accumulating multiple exposures of the same (moving) object, effectively increasing the integration time available to collect incident light. The object motion must be synchronized with the exposures to ensure a crisp image. The TDI method of line scanning provides dramatically increased responsivity compared to other video scanning methods and permits much greater scanning speeds in low light, or allows reduced lighting levels (and costs) at conventional speeds.

Benefits
More speed: With more effective integration time, you can increase the speed of the target object or inspection web.
Less light, less expense: Instead of high-powered, high-cost, high-temperature halogen lighting with DC power, you can use high-frequency AC or even LED lighting, profoundly lowering your system maintenance costs. TDI operation effectively averages out fluctuations in light intensity to represent a DC light source. This factor alone can justify the increased cost of a TDI sensor versus the cost of using DC regulated light source and a line scan image sensor.