When can prior art references be combined to invalidate patent claims as obvious under 35 U.S.C. § 103? Here is one case providing a lesson on this question. In Nidec Motor Corporation v. Zhongshan Broad Ocean Motor Co. Ltd., No. 2016-2321, 2017 U.S. App. LEXIS 15923 (Fed. Cir. Aug. 22, 2017), the Federal Circuit upheld the Patent Trial and Appeal Board’s (“Board”) determination that the claims of U.S. Patent No. 7,626,349 were invalid as obvious.
The ‘349 patent is directed to an electric motor in an HVAC system that uses sinewave commutation to rotate the motor. The Board rejected the claims of the ‘349 patent as obvious over a combination of U.S. Patent No. 5,410,230 (“Bessler”), which taught an HVAC system with a motor, and a doctoral thesis by Peter Franz Kocybik (“Kocybik”), which taught sinewave commutation. The Board determined that combining the references “would have provided predictable results to address known problems associated with other types of motors.” Nidec, the Appellant, conceded that the claimed elements were described in the prior art. Nidec argued that Bessler taught away from the asserted combination because adding sinewave commutation of Kobycik to the HVAC system of Bessler would increase the complexity of Bessler’s system, contrary to the goal of Bessler to simplify HVAC systems. Bessler states that the purpose of its invention is “to provide a central [HVAC] system which does not require a system controller.” The Court disagreed, holding that Bessler does not criticize or discourage sinewave commutation, or even mention it at all. The Court held that “[Bessler’s] statement [on removing the system controller] does not teach away from sinewave communication” as Nidec argued.
While the Court did not address the issue in detail, it is worth noting that the Kobycik reference does not teach or suggest using sinewave commutation in HVAC systems, or HVAC systems at all. The Board determined that one of ordinary skill in the art could have used the sinewave commutation of Kobycik with the HVAC system of Bessler, and Bessler was enough to teach HVAC systems. While Kobycik is certainly directed to operation of motors, the Board appears willing to rely on a reference that doesn’t appear related to HVAC systems to modify an HVAC system.
Lessons for Practice
This case reinforces the difficulty of overcoming obviousness rejections when all elements of a claim are shown in the prior art. Many patents are directed to simplifying older systems, but this simplification alone does not automatically teach away from adding in a new element. The Court appears to be looking for explicit criticism of an element, so unless the prior art specifically discourages the claimed element, avoid arguing that the reference teaches away from the combination. Furthermore, even if the cited references seem unrelated (as with Kobycik), focus arguments against what the reference teaches or suggests as related to the specific claimed elements, rather than to the field of technology of the claims.