Patent attributes
A simple and compact rotary cutter unit capable of detecting a home position of a rotary cutter, and a printer device having the rotary cutter unit. A radially outwardly extending fin-shaped detected member is arranged on an end portion of the rotating blade opposed to a second gear of the rotating blade. A photosensor is arranged within a main frame of the printer device so that the photosensor may detect the fin-shaped member when the rotating blade is positioned at the home position. The fin-shaped member and the photosensor are not positioned outside relative to both ends of the rotating blade in relation to the direction of the rotational axis of the rotating blade. Therefore, it is not necessary to increase the width of the printer device due to the presence of the fin-shaped member or the photosensor, whereby the printer device may be compactly constituted.