The principle of equivalence means that one or more technical features of the object accused of infringement are different from those protected by the independent patent claim, but they can be identified as the same technical features after analysis. In this case, it should be considered that the alleged infringement belongs to the scope of patent protection. Equivalence should be the substitution of specific technical features, not the substitution of complete technical solutions. The application of the principle of equivalence determines that the infringement is limited to whether the specific technical features of the accused infringer are equivalent to the corresponding necessary technical features in the independent patent claim, rather than whether the overall technical scheme of the accused infringer is equivalent to the technical scheme defined in the independent patent claim.
That is, the claim in the patent document is compared with the behavior of the accused infringing product.