In considering whether an invention is obvious, the Patent Office must only utilize references that are analogous. In practice, this threshold inquiry rarely stops examiners from applying references far afield from the claimed invention. Previous posts have discussed some details regarding the test for whether prior art is analogous (see here and here, for example).

Today, however, we discuss how some examiners use the mere fact that a reference is in an analogous art to be a sufficient condition for obviousness. This of course is wrong - being analogous is a necessary but not sufficient condition. A recent informative decision by the PTAB address an example where the Petition basically followed the same approach many examiners use on a daily bases - that because a reference is in the field of the invention, for example, it would therefore be obvious to combine its features with another reference. The PTAB summarized the issue as follows (internal citations omitted):

Analogous art is merely a threshold inquiry as to whether a reference can be considered in an obviousness analysis. Demonstrating that a reference is analogous art or relevant to the field of endeavor of the challenged patent is not sufficient to establish that one of ordinary skill would have had reason to combine its teachings with other prior art in the manner set forth in the claim. Mere compatibility of the references is likewise not sufficient.

So, do not let examiner short-cut the obviousness analysis. As confirmed by the Supreme Court in KSR, obviousness requires “a reason that would have prompted a person of ordinary skill in the relevant field to combine the elements in the way the claimed new invention does.”

On the flip side, where the applicant is attempting to fend off prior art as non-analogous, great care is required. Even where the applicant has good arguments that a reference is non-analogous, the applicant needs to ensure the the claim scope is commensurate with the arguments. A recent PTAB case (Appeal 2019-002037, Application 15/111,826) illustrates that relying on limitations in the preamble can kill a good non-analogous art argument.

The case relates to a surface heater for a household appliance, comprising: an electrically insulating insulation layer having a permittivity which changes as a function of temperature; at least one strip-shaped heat conductor applied to the electrically insulating insulation layer, and at least one measuring electrode electrically insulated in relation to the at least one heat conductor and applied on a same side of the insulation layer as the heat conductor.

The applicant argued that the cited art was not analogous, as it related to a surface heater for an automobile window, and thus was outside the field of cookware. A first problem was that the cited art had some broadening language suggesting the invention could be used outside of automobile glass, such as window glass in “any type of vehicle or building…”

While this still did not reach to surface heaters for a household appliance, the PTAB closed the gap in two basic steps. First, the PTAB pointed out that the applicant’s specification also had broadening language indicating that the heater could be applied to dishwashers, water boilers, coffee machines, hair straighteners, and kitchen machines. While such an argument should not undue claim limitations requiring otherwise, the PTAB’s second step closed the gap. Specifically, the PTAB noted that the body of the claim does not recite any limitation relating to the household appliance, and the language “for a household appliance” is interpreted to merely recite an intended use of the surface heater (“[t]hat is, claim 13 is directed to a surface heater having an intended use, and
not to a combination of the surface heater and a household appliance.) From there, it was then easy for the PTAB to dismiss the non-analogous art argument.

Hopefully your analogous and non-analogous art arguments fare well in 2020!