No Written Description Where Patent Fails to Attribute Claimed Functions to Disclosed Structures
“A patent owner cannot show written description support by picking and choosing claim elements from different embodiments that are never linked together in the specification.”
In Flash-Control, LLC v. Intel Corp., No. 2020-2141 (Fed. Cir. July 14, 2021), the Court of Appeals for the Federal Circuit affirmed the summary judgment of the Western District of Texas, invalidating Flash-Control’s two asserted patents for lack of written description in support of certain claim elements. Although the patents’ shared specification arguably depicted the claims’ structural elements, the specification failed to attribute the claimed functions to those structures.
The two Flash-Control patents asserted against Intel, U.S. Patent Nos. 8,531,880 and 8,817,537, claim performance enhancing improvements to computer memory systems that reduce the number of write requests to non-volatile memory. The patents each claimed “a memory system” comprising structures such as non-volatile memory, volatile memory, and various buffers configured to carry out specific process steps.
In its motion for summary judgment, Intel asserted that the patents’ specification lacked written description for the “second buffer” recited in the claims that performs two process steps: (1) “store a write request” and (2) write “a portion of a page to volatile memory.” Id. at 8. In response, Flash-Control pointed to certain structural depictions in the patents’ illustrations as well as various passages included in the exemplified embodiments, attempting to show compliance with the written description requirement.
The district court ruled, and the Federal Circuit agreed that although Figures 6 and 9 of the `880 patent appear to depict buffers connected to non-volatile memory, “there is nothing in the figures or text description of the figures to indicate whether those buffers act as the second buffer—i.e., whether they can store a write request to modify a portion of a page. . . .” Id. at 8 (emphasis in original). Flash-Control’s further reliance on buffers depicted in Figures 3 and 12 likewise failed, with the Federal Circuit noting that nothing in the patent specification indicates that the buffers write a portion of a page to volatile memory. Id.
Turning to passages in the exemplified embodiments, Flash-Control, for example, asserted that a reference to two “new commands” that “[r]ead byte out of page” and “[w]rite byte out of page” describe the two process steps performed by the second buffer. While acknowledging that the disclosure “comes the closest to supporting the claimed technique,” the Federal Circuit concluded that “the specification never elaborates on these ‘new commands’ and does not indicate whether they interact with any buffer or volatile memory.” Id.
In ruling on Intel’s summary judgment motion, the district court rejected Flash-Control’s assertion that a person of ordinary skill would consider the foregoing disclosures together with other exemplified features, as a whole, in understanding that the second buffer and its operations had been adequately described. In its appeal, Flash-Control argued that the district court “improperly required it to show that a single embodiment of the `880 patent ‘disclose[d] all claim limitations for written description.’” Id. at 9.
In support of that argument, Flash-Control relied on LizardTech, Inc. v. Earth Resource Mapping, Inc., 424 F.3d 1336, 1345 (Fed. Cir. 2005) in which the Federal Circuit held “[a] claim will not be invalidated on section 112 grounds simply because the embodiments of the specification do not contain examples explicitly covering the full scope of the claim language” and that the written description is read from the perspective of the person of ordinary skill who “brings the knowledge of what has come before.”
The Federal Circuit responded to its prior ruling by emphasizing that LizardTech “did not alter this court’s precedent stating that ‘enough must be included [in the specification] to convince a person of skill in the art that the inventor possessed the invention.’” Flash-Control, No. 2020-2124 at 10 (quoting LizardTech, 424 F.3d at 1345). The Federal Circuit noted that it had previously “explained that the elements of a claim must be treated as an ‘integrated whole rather than as a collection of independent limitations.’” Id. (quoting Novozymes A/S v. DuPont Nutrition Biosciences APS, 723 F.3d 1336, 1349 (Fed. Cir. 2013)).
The Federal Circuit concluded its analysis with sound guidance for practitioners, explaining that “[t]he written description requirement is not met when, as here, the specification provides at best disparate disclosures that an artisan might have been able to combine in order to make the claimed invention.” Id. (citing Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1352 (Fed. Cir. 2010)). In other words, the “patent owner cannot show written description support by picking and choosing claim elements from different embodiments that are never linked together in the specification.” Id.
This case illustrates the ongoing risks inherent in claim drafting and amendment during patent prosecution that proceed long after the patent specification’s disclosure is finalized. And, the Federal Circuit’s ruling in this case emphasizes the need to insure not only that the claimed structures but also their claimed functions are adequately described and, where necessary, linked together in the patent’s specification.