Dual-line monochrome line scan cameras
This type of camera offers a solution when applications require functionality between standard, single-line cameras and highly sensitive TDI line scan cameras.
As distinct from TDI line scan cameras, the data from the two linear sensors is read out via two separate horizontal readout registers, retaining the ability to have exposure control on both pixel stages. Changes in speed or starting/stopping of the conveyor belt or object do not cause problems for this type of line scan camera and exact adjustment can be achieved.
Because of the dual-line sensor technology, this type of line scan camera offers significant sensitivity improvements compared to standard line scan cameras. Depending on the illumination in place, these cameras can be used either in normal mode (single-line mode) or in high sensitivity mode, using both sensor lines with the exposures shifted in order to accumulate additional charge. Also, the two lines can be either binned to give a high-sensitivity 'tall pixel', or operated in area mode where both pixels are exposed at the same time, every two lines giving double the line rate of the single pixel line scan camera. Due to their on-chip architecture, these cameras are bidirectional, meaning that they operate in either direction.