First, internal evidence. That is, it consists of patent claims, specifications and patent examination documents. The court requires that all internal evidence records be considered to determine the significance of the claim. The second is external evidence, including from dictionary definition to expert evidence. The judge of the court of first instance has the discretion to decide whether to adopt external evidence, but if the internal evidence can reasonably explain the claim, it is not necessary to consider external evidence.
Second, literal infringement. Literal infringement means that the product or method accused of infringement has all the technical characteristics in the patent claim compared with the patent claim; Or every restriction or element in the claim can be found in the accused infringing product or method, then the accused infringing product or method constitutes a literal infringement of the patent.
Third, it is equivalent to infringement. When dealing with patent infringement disputes, the principle of equivalence has always been the most problematic and controversial. Equivalence theory originated in the United States, which is used to adjust the boundary between increasingly diverse inventions and the degree of interpretation of patent specifications, and is usually used as the theoretical basis for strengthening patent rights. Equivalent infringement is relative to literal infringement, which means: compared with the patent claim, one or several elements of the product or method accused of infringement are different from the restrictions or elements in the claim, but there is only immaterial difference between them; In other words, one or several elements in the accused infringing product or method are equivalent to one or several restrictions or elements in the claim, then the accused infringing product or method constitutes equivalent infringement of the patent.