After image correction in the main scan direction by the shift units, the paper is fed to the transfer timing roller [A]. The nip of the registration gate roller [B] opens to free the paper.
The transfer timing sensor [A] detects the leading edge of the sheet to start the sub scan registration.
In order to adjust feed of the leading edge so it aligns correctly with the start of image transfer, after the transfer timing sensor goes ON, machine will calculate the amount of time to start paper feed so the image will be positioned correctly on the sheet in the sub scan direction. Based on the results of these calculations, the speed of the transfer timing motor [B] is increased or decreased to adjust the rotation speed of the transfer timing rollers [C] for the ideal timing to feed the paper to the PTR unit.