Which statement is true regarding prior use before the filing date?

Prior use before the filing date can indeed establish a defense against a claim, particularly in patent litigation. This concept is rooted in the principle that if a person or entity can demonstrate they were using the invention before the patent owner’s filing date, they may successfully argue that they have prior use rights. This defense is pivotal in protecting parties who have been using an invention in good faith without knowledge of the patent, allowing them to continue their business without infringing.

This is especially relevant under the America Invents Act (AIA) which introduced the “prior user rights” defense in certain circumstances where the defendant can show that the use occurred before the effective filing date of the patent. This defense serves to prevent the patent holder from asserting rights against someone already practicing the invention before they sought patent protection.

In contrast, other options do not accurately present the legal framework surrounding prior use. For example, prior use may affect the validity of a patent but does not inherently ensure that the patent is invalid. Furthermore, prior use does not automatically qualify as prior art under all circumstances; its applicability can depend on various factors, including the type of patent and jurisdiction. Lastly, while it is applicable in litigation, prior use can also be raised in various contexts, not solely restricted