Patent infringement: refers to the act of exploiting a patent without the permission of the patentee. Patent infringement can be divided into: 1) counterfeiting others' patents; 2) There are two methods: passing off non-patented products as patented products and passing off non-patented methods as patented methods. Anyone who infringes the patent right shall bear the punishment of stopping the infringement, confiscating the illegal income, compensating the losses of the patentee and imposing a fine. If the circumstances are serious enough to constitute a crime, criminal responsibility shall be investigated according to law. The limitation of action for patent infringement is two years, counting from the date when the patentee or interested party knows or should know about the infringement. If the patentee fails to pay the appropriate royalty before the patent right is granted after the publication of the application for a patent for invention, the limitation period for requesting the royalty is two years, counting from the date when the patentee knows or should know that others are using his invention. However, if the patentee knows or should know before the patent right is granted, it shall be counted from the date when the patent right is granted.