A method for achieving accurate page margins on a media and a duplex imaging apparatus thereof. The method comprises: detecting a leading edge position by an edge sensor and a first left-to-right position of the media by an alignment sensor in a first imaging path; imaging a first side of the media in a print zone of the duplex imaging apparatus; removing the media from the print zone and disposing the media in a second imaging path; detecting a leading edge position by the edge sensor and a second left-to-right position of the media by the alignment sensor; determining a carrier reset distance by calculating a difference between first and second left-to-right positions, and shifting a print image by a distance substantially equal to the carrier reset distance thereby achieving accurate page margins for imaging a second side of the media with the print image. In another embodiment, the first left-to-right position can be determined by feeding the media into a preset first left-to-right position.