Interline Transfer CCD (IT-CCD) is another technique that supports the readout process of CCD sensors. There are also Full Frame CC D (FF-CCD), Frame Transfer CCD (FT-CCD) and Frame Interline Transfer CC D (FIT-CCD).
In all methods, the charge image of the CCD sensor is first read out before a new image can affect the charge state of the potential wells, which are very small capacitances. In the case of interline transfer, every second pixel line on the CCD sensor is masked and is not available for exposures. During readout, the charges of the exposed pixel lines are transferred to the intermediate line and then shifted line by line to the readout amplifier. The process allows very short exposure times.
In addition to the Interline Transfer CCD (IT-CCD), there are also Frame Transfer CCD (FT-CCD), Full Frame CCD (FF-CCD) and Frame Interline Transfer CCD (FIT-CCD).