The principles of judging patent infringement include universal application principle, equivalence principle, estoppel principle, gift principle and intentional exclusion principle. Patent infringement is mainly judged according to the patent law and related judicial interpretations.
Legal basis: Interpretation of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Patent Infringement Disputes.
Article 7 The people's court shall examine all the technical features recorded in the patent claim when judging whether the alleged infringing technical scheme belongs to the scope of patent protection.
If the technical scheme accused of infringement contains the same or equivalent technical features as all the technical features recorded in the right claim, the people's court shall determine that it belongs to the protection scope of the patent right; If the technical features of the technical scheme accused of infringement lack more than one technical feature recorded in the claim compared with all the technical features recorded in the claim, or more than one technical feature is different or the same, the people's court shall determine that it does not belong to the protection scope of the patent right.