Page printers may take various forms, in part dependent upon the type of print engine. For example, page printers may include electrophotographic printers and ink jet printers. A page printer typically has a bit map memory large enough to contain at least one full page image area so that a page to be printed can be fully composed before driving the print engine to actually print on paper or other recording medium.
A page is allocated space in the bit map memory sufficient to image a full physical page, this amount of memory being termed a page image area. The page information is then placed into the page image area during rasterization. After rasterization is complete, the image information is transferred from the page image area to the print engine during serialization.
Normally, if the bit map memory is large enough, more than one page can be fully rasterized and stored in memory for subsequent serialization. Serialization can occur at the same time as rasterization. In the usual case, after one page image area is fully rasterized, a second and subsequent page image areas are allocated and rasterized. Serialization of rasterized pages can occur independently of rasterization.
When no further bit map memory is available to hold an entire page image area to rasterize another page, further rasterization is postponed until an already-rasterized page image area is serialized to the print engine for printing. After serialization of a page image area, that area is then returned to the available bit map memory pool to be used to rasterize another page.