> An infringing device must contain every single thing listed in the claims. An infringing device must contain every single thing listed in at least one of the

> An infringing device must contain every single thing listed in the claims. An infringing device must contain every single thing listed in at least one of the claims. If you infringe on any single claim, then you infringe. Usually what happens is that claim 1 is really broad, and then there's a sort of tree of claims with claim 1 at the root and more specific claims further down the tree. The early claims may well get invalidated when an infringement case goes to court, but the patent-holder hopes that the later more specific ones will survive and still be broad enough to cover what their rivals are doing. (For the avoidance of doubt, I agree with the general point brian_cloutier is making.)