“But my invention has a totally different purpose than these prior art references!” Every patent professional has heard this from inventors, or perhaps even recognized it themselves when reading an office action. Many times there is invention in applying known elements to solve a new problem or achieve a new purpose not recognized in the prior art. So how does the patent professional turn these “different purposes” into legal arguments against non-obviousness? Simply arguing that the claimed invention has a different purpose, without more, generally does not move the needle with examiners.
To understand a possible reason why this is so, one must put themselves in the examiner’s shoes. At this point in the game (there is a standing 103 rejection that the applicant must address), the examiner has found prior art that, when combined for some supposedly reasonable reason, appears to show the claimed elements. An applicant generally cannot effectively claim “a purpose” (more on this in another post), and so the examiner is simply unmoved that the applicant has recognized another reason to combine or modify the references. Arguing that the examiner’s reasoning for combining is different than the motivation of the inventors is difficult in view of MPEP 2144.IV (“Rationale different from applicant’s is permissible”).
When thinking about the purpose of an invention, the MPEP does provide some guidance that looks to the cited art. Namely, whether a modification renders the cited art unfit for its intended purpose has some relevance. See MPEP 2143.01 (“Suggestion or Motivation To Modify the References”), which discusses the issue in Section V (“The proposed modification cannot render the prior art unsatisfactory for its intended purpose”). However, this looks to the purpose of the prior art, not necessarily the purpose of the invention.
Another area of the MPEP that can be relevant to the purpose of an invention is in terms of overlapping ranges and obviousness of species. MPEP 2144 discusses the case where a reference’s disclosed range is so broad as to encompass a very large number of possible distinct compositions, and how this might present a situation analogous to the obviousness of a species when the prior art broadly discloses a genus, citing among others, In re Baird, 16 F.3d 380, 29 USPQ2d 1550 (Fed. Cir. 1994). In such a case, one might consider the a prior art teaching of a preference for a compound (for a particular purpose) that leads away from the claimed compound as a relevant argument against non-obviousness. However, such arguments tend to lend themselves mostly to the chemical arts in a very particular situation.
How, then, can the inventor’s different purpose be used in arguing obviousness?
Some indirect approaches present themselves depending on the particular facts of the case.
To help explain why there is not a proper motivation to combine in the first place - consider if there is a way to argue that combining as suggested by the examiner would only frustrate the prior art’s purpose (related to unfit for intended purpose), and that the only reason one would recognize to make the combination is if they knew the inventor’s purpose (but that is not allowed because it is impermissible hindsight), or
To argue non-analogous prior art - the field of endeavor prong of this test can sometimes lend itself to the purpose of the invention as compared to the prior art. Likewise, the different problem prong may also provide a way to argue about the purpose of the invention as compared to the cite dart.
While this is a start, it would be great to hear other ideas of how you can use an inventor’s different purpose in arguing against a rejection.