Printing apparatus having movable sensor and method for using

A printing apparatus comprising:

• a conveyance mechanism configured to convey a sheet in a predetermined direction;
• a printing unit including a print head and configured to print an image on the sheet conveyed by the conveyance mechanism;
• a sensor having an image pickup device provided under a printing region of the print head and configured to image a sheet surface that is on a side opposite to a printing surface of the sheet on which an image is formed by the print head;
• a platen including a plurality of openings at different locations in the predetermined direction and configured to support a sheet conveyed by the conveyance mechanism, wherein the plurality of openings are located such that the image pickup device can image a sheet surface of the conveyed sheet through any one of the plurality of openings;
• a movement mechanism configured to move the image pickup device to any one of a plurality of positions corresponding to the plurality of openings;
• and
• a control unit configured to control the movement mechanism such that the image pickup device moves to a position which does not correspond to any of the plurality of openings when performing a maintenance operation of the print head.