Abstract: A duplex printing method in a printing apparatus having a duplex printing function printing incoming print data on both sides of a print sheet includes 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 a single sheet among the images of the pages, if it is determined that there are the images having 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, variably scheduling a printing sequence of the pages to be printed using the dual queue and performing the duplex printing function, and repeating the above operations until all of the incoming print data are completely received and printed. Therefore, a memory can be efficiently used, and the scheduling of the printing sequence of the pages to be printed can be simplified.

Abstract: A device for printing a presentation document comprises a printing unit for printing data received from a computer, a print medium register unit which set up a print medium for printing the data, a print feeding unit which feeds the predetermined print medium to the printing unit, and a control unit which generates a control signal so as to output the data to the printing unit after reading the print medium type determined at the print medium register unit and selecting the corresponding print medium at the print feeding unit.

Abstract: In a technique for processing a ROM image when supplying of electrical power to a laser printer has been interrupted during the downloading of the ROM image to a flash memory, if the ROM image is abnormally downloaded to the flash memory, the ROM image can be loaded into the flash memory again. Accordingly, although the ROM image is abnormally loaded into the flash memory in the laser printer, it is possible to normally use the laser printer.