The patent law stipulates that the right to apply for a patent and the patent right can be transferred. At the same time, it is stipulated that if the right to apply for a patent or the patent right is transferred, the parties concerned must conclude a written contract, which will take effect after it is registered and announced by the China National Intellectual Property Administration Patent Office. ?

In practice, there is a period of time between the signing of the transfer contract by both parties and the registration announcement of the Patent Office, so the legal problems arising during this period involve the validity of the transfer contract. According to the contract law, this contract shall come into effect as of the date of signature by both parties. However, due to the characteristics of the patent application itself, the patent application or the transfer of the patent right should be registered and announced by the patent office, so that the public can understand the legal situation of the change of the patent subject. Although according to the contract law, the transfer contract is signed by both parties, the effectiveness of the transfer contract cannot be opposed to the third party because it has not been announced, that is, the transferee (new patentee) can not exercise the rights of the patentee as a patentee for the time being, such as not allowing others to implement it and preventing others from infringing. Only after the registration and announcement in the Patent Office can the assignment contract become effective for the third party and become fully effective. Prior to this, the transfer contract only came into effect between the parties, which can be said to be partial.