legal ground
patent law of the people's republic of china
Article 66 Where a patent infringement dispute involves an invention patent of a new product manufacturing method, the unit or individual that manufactures the same product shall provide proof that its product manufacturing method is different from the patented method.
Where a patent infringement dispute involves a patent for utility model or a patent for design, the people's court or the administrative department for patent affairs may require the patentee or interested party to issue a patent evaluation report made by the patent administrative department of the State Council after searching, analyzing and evaluating the relevant utility model or design as evidence for hearing and handling the patent infringement dispute; The patentee, interested party or accused infringer may also issue a patent evaluation report on his own initiative.
Article 67 In a patent infringement dispute, if the accused infringer has evidence to prove that the technology or design he implemented belongs to the existing technology or design, it does not constitute patent infringement.