Printing apparatus, printing method and sheet feeding units thereof.

摘要

A printing apparatus capable of being used by freely selecting a plurality of sheet feeding units each having a different controlling method. It is discriminated which one among plural kinds of sheet feeding units is fitted, and printing is controlled and a motor for a sheet feeding unit is controlled based on the result of discrimination and an output from a sensor disposed on the sheet feeding unit. Especially, in the case that a roll-shaped paper feeding unit is fitted, it is judged that a printing medium reaches the position where printing can be started when a TOF sensor detects black color, and in the case that a cut sheet feeding unit is fitted, it is judged that the recording medium reaches the position where printing can be started when the TOF sensor detects white color.