A joint-inventor (that is, one inventor of a group of inventors of a patent) who does not assign his patent rights remains in full possession of those rights. A person or entity that does not receive rights to the patent from every inventor is considered as a partial assignee. The partial assignee must share his/her patent rights with the joint-inventors who chose not to assign their rights.
The partial assignee and the non-assigning joint-inventors must account to each other for and share all the profits they have earned from their patent rights. Each part is advised to consult a Patent Attorney to discuss his/her rights in this scenario. It is recommended the partial assignee and the non-assigning joint inventors have different Patent Attorney representation, as the scenario may present conflicts of interest.
If you are interested in more detail related to your situation it is best to speak with an attorney.
Yuri Eliezer heads the intellectual property practice group at Founders Legal. As an entrepreneur who saw the importance of early-stage patent protection, Yuri founded SmartUp®. Clients he has served include Microsoft, Cisco, Cox, AT&T, General Electric, the Georgia Institute of Technology, and Coca-Cola.
Source: Smartup Legal