Patent ID: 8339658

Claim:
An image forming apparatus, comprising: a video memory; a load management unit that loads page data on a print image into the video memory page by page; a print engine that performs printing using the page data stored in the video memory; and a main management unit that, when the printing of a page is part of an electronic sort process, causes the video memory to retain the page data if there is a subsequent page to be printed using the page data, and deletes the page data from the video memory if there is no subsequent page to be printed using the page data; a page control unit that issues a load request for the page data page by page, wherein if page data on a page specified by the load request has not been loaded in the video memory, the main management unit causes the load management unit to load the page data specified by the load request into the video memory, and if the page data specified by the load request has been loaded in the video memory, the main management unit ignores the load request; wherein the main management unit registers, in a list, a record indicating a correlation between a print page number and a document page number specified in the load request, wherein the print page number represents a serial number of a print page, and the document page number represents a page number of the page data used for the printing; and when the load request is issued, if the document page number specified in the load request is not registered in the list, the main management unit causes the load management unit to load the page data corresponding to the document page number into the video memory, and if the document page number specified in the load request has already been registered in the list, the main management unit ignores the load request.