Top 50 Patent Holders in US

http://ificlaims.com/index.php?page=misc_top_50_2013

As for companies with camera business, the following are extracted and ranked (although they do have other businesses as well):

Company	Ranked for Camera Makers	Overall Ranking
Samsung	1	2
Canon	2	3
Sony	3	4
Panasonic	4	6
Ricoh	5	17
Fujifilm	6	42