Analogous Patent Prior Art from Different Field of Endeavor?

If you are trying to disqualify a prior art reference as non-analogous in either patent prosecution or litigation, here is a case to remind you of limitations of such arguments. In Smartdoor Holdings, Inc. v. Edmit Industries, Inc., No. 2016-2152 (Fed. Cir. Sept. 7, 2017) (non-precedential), the Court affirmed an Inter Partes Review finding of the Patent Trial and Appeal Board (PTAB) that claims of U.S. Patent No. 6,484,784 were obvious over a combination of two prior art references. In so doing, the Court rejected the IPR petitioner’s argument that one of the references should have been disqualified as non-analogous patent prior art.

The only independent claim of the ’784 patent at issue recites a door moved by an electric motor and including a generator configured such that moving the door from a first to a second position

causes the generator to produce power to apply a braking force to slow movement of said door from said first position to said second position into power at least one auxiliary device.

The reference relied upon to teach the braking force did not disclose a door, and therefore the petitioner argued it was non-analogous patent prior art.

The Federal Circuit disagreed. One test for analogous patent prior art is whether it is “from the same field of endeavor [as the claim being analyzed], regardless of the problem addressed.” However, prior art, even if “not within the field of the inventor’s endeavor,” can qualify as analogous patent prior art under a second test that queries “whether the reference still is reasonably pertinent to the particular problem with which the inventor is involved.”

In this case, the PTAB acknowledged that the reference failed to disclose a door, but found the reference to be “analogous art because it is relevant to the problem faced by the inventor of the ’784 patent: the problem of braking in electronic devices.” The PTAB’s finding that the reference “discloses an approach to that problem by observing energy from a motor, operated as a generator, for the purposes of breaking,” was supported by substantial evidence.

The court also rejected the petitioner’s argument that the references could not have been combined because one was digital and one was analog, and therefore the secondary reference would allegedly have destroyed the principal of operation of the primary reference. The Court explained that the “overall principle of operation of the device,” which was “to slow the movement of the door,” would have been met by substituting the analog component into the digital device.

Lessons for Practice

This case shows why it is very rare to rest and appeal in ex parte prosecution on an argument that prior art is non-analogous. I am not saying that such arguments are never legitimate, nor that they cannot succeed. However, practitioners should remember that the field of analogous patent prior art can be fairly wide.

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Functional Claiming After Williamson v. Citrix
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