The software giant applied for the patent in 2005, and was granted it on August 19, 2008. US patent number 7,415,666 describes "a method and system in a document viewer for scrolling a substantially exact increment in a document, such as one page, regardless of whether the zoom is such that some, all or one page is currently being viewed".
Doesn't this say something about the current state of IP laws in the US (And probably elsewhere). Surely the logic that supports page up and page down has been around for at least as long as we've had keyboards that have PgUp and PgDn keys.
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