The most basic principle to judge whether the patent right is infringed is comprehensive coverage, that is, the product or method should have every feature described in the claim and be indispensable.
Therefore, on the basis of others' patents, it is necessary to re-judge whether it still contains all the technical features in the claim after revision. For example, adding one or more technical features on the basis of a patent will still face the risk of infringement, because it still contains all the technical features of the claim; If one or more technical features are reduced or changed on the basis of patents, the risk of infringement may be successfully avoided.
It is worth mentioning that the possession of every feature in the patent claim here, including the technical features of the product, is completely consistent with the description of the patent claim, that is, the same infringement; It also includes that the product and the technical features recorded in the claims achieve basically the same function and achieve basically the same effect by basically the same means, which can be thought of by ordinary technicians in this technical field without creative labor, which is equivalent to infringement.
Therefore, even if some technical features are reduced or changed, it may be judged as patent infringement according to the principle of equivalent infringement. This requires that when changing and modifying, it is best to reflect the technical effect different from the patented technology.