(Reuters) - Facebook Inc’s virtual reality unit Oculus VR is facing a lawsuit alleging it incorporated without authorization a smaller competitor’s patented technology into its Rift headset.

FILE PHOTO - An attendee tries the Oculus VR Inc. Rift Development Kit 2 (DK2) headset at the 2014 Electronic Entertainment Expo, known as E3, in Los Angeles, California, U.S. on June 11, 2014. REUTERS/Kevork Djansezian/File Photo

Techno View IP Inc, a Newport Beach, California-based technology licensing firm, sued Facebook and Oculus on Thursday for infringing a 3D imaging patent owned by the VR headset maker ImmersiON-VRelia.

According to the complaint filed in federal court in Delaware, ImmersiON-VRelia, which has offices in Spain and California, agreed to let Techno View litigate the patent on its behalf.

The lawsuit comes as Facebook weighs its options following a $500 million verdict in an unrelated lawsuit brought over its VR technology by video game developer ZeniMax Media Inc. A Dallas federal jury in February found Oculus used copyrighted computer code developed by video game designer John Carmack while employed at ZeniMax.

Lawyers for Oculus and Facebook have said they will seek to have the verdict set aside.

ImmersiON-VRelia makes VR headsets similar to the Oculus Rift, as well as a VR device for use with smartphones. Techno View said in its lawsuit ImmersiON-VRelia’s chief executive, Manuel Gutierrez Novelo, attained several patents between 2003 and 2006 on various aspects of VR technology.

Techno View said Oculus and Facebook specifically infringed a patent held by ImmersiON-VRelia on a method of generating left and right perspectives in a 3D video game. Techno View said it may add claims relating to other patents owned ImmersiON-VRelia at a later date.

Facebook acquired Oculus for an estimated $3 billion in 2014. Facebook chief executive Mark Zuckerberg has predicted that virtual reality “will be part of people’s daily lives,” revolutionizing industries like media, education and medicine.

Facebook and Oculus did not immediately respond to requests for comment on Techno View’s lawsuit.

The case is Techno View IP Inc v. Oculus VR LLC and Facebook Inc, 17cv00386, in the U.S. District Court for the District of Delaware.