Come February of 2014, a slew of selective laser sintering patents held by 3D Systems (NYSE:DDD) will be expiring. The last time key technology patents associated with 3-D printing expired, it sparked the open source movement that spawned the consumer-oriented 3-D printing revolution. In the video below, Fool.com contributor Steve Heller goes into detail about the patents, what their expiration could mean for the industry at large, and what it will likely mean for both 3D Systems and Stratasys (NASDAQ:SSYS), parent of MakerBot.