When determining whether the claim lacks the necessary technical features, we should analyze whether the set of technical features recorded in the claim can solve the technical problems pointed out in the specification and achieve the expected technical effect, especially whether the claim records the remarkable technical features that have made creative contributions to the existing technology.
If the independent claim lacks one or several technical features and cannot solve the most important technical problems pointed out in the specification, the independent claim shall be amended to overcome the above defects.
If the independent claim records the technical features that have made creative contributions to the existing technology, and the unwritten technical features pointed out by the examiner are only for solving the secondary technical problems mentioned in the specification, the claim can be modified without modifying the claim, and the description of technical problems in the creative content part of the specification can be modified to make it adapt to the technical scheme of the independent claim.