hmm let me guess (and there's a hint in the article) ... us patents ? A quick research gives about 3757 patents concerning laser printing : http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sec... . Apart from the fact that there are still efforts to be made to have the same kind of "open source" activity in the hardware world imho.
In 1991 I had a lovely little Apple Laserwriter IIg networked laser printer. In the intervening 20 years all of the patents covering that device will have expired.
Surely some of the subsequent patents have been related to making the printer cheaper, so that could lead to a price disadvantage, but it should be possible to make a fine patented free laser printer.
(of the many printers I've had subsequently, none have performed as well in the "paper jam" and "mysteriously hung network printer" category. The IIg was unable to reliably feed 6x8 envelopes, but other than that was perfect.)
