If a prior art device performs all functions of an apparatus claim, what is true about the prior art?

The correct answer is that the prior art may be considered as non-infringing due to structural differences. In the context of patent law, anticipation requires that a prior art reference discloses all elements of the claimed invention, including its structure and function. If the prior art device performs all functions outlined in the apparatus claim, it must also share the same structural features for it to fully anticipate the claim.

The anticipation standard is stringent; it does not merely focus on the functionality but also on how the invention is physically constructed. Consequently, if there are significant structural differences between the prior art and the claimed invention, the prior art may not fully anticipate the claim despite performing similar functions.

Understanding the role of structure is crucial in patent examination, as it can be the key differentiator that determines whether a claim is anticipated or it remains novel. Even if the prior art performs all the functions of the claimed invention, the potential structural differences could render it non-infringing. This highlights the importance of careful analysis when assessing the relevancy of prior art against a patent claim.