Source: https://patentplanetblog.blogspot.com/2017/08/
Timestamp: 2019-04-25 08:50:04+00:00

Document:
In Athena Automation Ltd v. Husky Injection Molding System Ltd., the Patent Trial and Appeal Board (PTAB) held that assignor estoppel does not prevent anyone who is not the patent owner from filing a petition for inter partes review to challenge patent validity.
"The only argument that Husky asserts in its Preliminary Response is that Athena is barred from bringing this Petition by the doctrine of assignor estoppel. Prelim. Resp. 1. Husky contends that Mr. Robert Schad, one of the named inventors of the ’536 Patent, is the founder, co-owner, President, Chief Executive Officer, and one of two directors on the Board of Directors of Petitioner Athena and is, therefore, in privity with Athena. Id. Thus, according to Husky, Athena is estopped from challenging the patentability of the ’536 Patent under the doctrine of assignor estoppel. Id.
The Federal Circuit has explained, [A]ssignor estoppel is an equitable doctrine that prohibits an assignor of a patent or patent application, or one in privity with him, from attacking the validity of that patent when he is sued for infringement by the assignee. . . . Assignor estoppel is thus a defense to certain claims of patent infringement. Semiconductor Energy Laboratory Co., Ltd. v. Nagata, 706 F.3d 1365, 1369 (Fed. Cir. 2013) (emphasis added) (citations omitted).
Under the AIA, “a person who is not the owner of a patent may file with the Office a petition to institute an inter partes review of the patent.” 35 U.S.C. § 311(a) (emphasis added). Consequently, under the statute, an assignor of a patent, who is no longer an owner of the patent at the time of filing, may file a petition requesting inter partes review. This statute presents a clear expression of Congress’s broad grant of the ability to challenge the patentability of patents through inter partes review.
In contrast to § 311(a), in International Trade Commission (ITC) investigations involving patent disputes brought under 19 U.S.C. § 1337(c), Congress provided explicitly that “[a]ll legal and equitable defenses may be presented in all cases.” From this statutory mandate, the ITC concluded that it must consider the defense of assignor estoppel in cases in which a patent owner may seek to have infringing goods excluded from the United States. See Lannom Mfg. Co. v. Int’l Trade Comm’n, 799 F.2d 1572, 1579 (Fed. Cir. 1986).
Congress issued no similar statutory mandate to the Office in connection with AIA post-grant reviews. Husky concedes that the Patent Office does not apply assignor estoppel in reexamination proceedings, but argues that assignor estoppel should be available to patent owners in inter partes review proceedings based on the adjudicative nature of the proceedings. Prelim. Resp. 15-25. However, none of Husky’s arguments addresses the language of § 311(a). Because we are not persuaded that assignor estoppel, an equitable doctrine, provides an exception to the statutory mandate that any person who is not the owner of a patent may file a petition for an inter partes review, we decline to deny this Petition based on the doctrine of assignor estoppel."

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