Duplex printing method of printing apparatus having duplex printing function

A duplex printing method in a printing apparatus having a duplex printing function printing incoming print data on both sides of a print sheet, the duplex printing method comprising:

• sequentially converting the incoming print data into images corresponding to respective pages and storing the images of the pages;
• determining whether there are the images having two side pages to be printed on both sides of the single print sheet among the images of the respective pages;
• upon determining that there are the images of the two side pages, forming a dual queue having both odd page image related information and even page image related information corresponding to the two side pages, respectively;
• variably scheduling a printing sequence of the pages to be printed the dual queue and performing the duplex printing function;
• determining whether even and odd pages relating to the two side pages of the dual queue are completely printed, erasing the dual queue upon determining that the two even and odd pages are completely printed, and rescheduling the printing sequence of the pages upon determining that the two side pages are not completely printed;
• determining whether the incoming print data are being received and performing the converting of the incoming print data upon determining that the incoming print data are being received;
• and
• upon determining that the incoming print data are not being received, determining whether a printing process of the pages is completed, terminating the converting of the incoming print data upon determining that the printing process is completed, and scheduling the printing sequence upon determining that the printing process of the pages is not completed.

A duplex printing method in a printing apparatus having a duplex printing function printing images on corresponding sides of print sheets, the duplex printing method comprising:

• forming a dual queue indicating that the images includes two side images to be printed on both sides of one of the print sheets;
• printing the images on the print sheet according to a printing sequence of the images;
• and
• modifying the printing sequence of the images in response to the dual queue when an error relating to the duplex printing function is detected in the printing apparatus.