CAFC Rules Patent Applications are Considered Pre-AIA Prior Art By Filing Date, Not Publication Date

Today, the U.S. Court of Appeals for the Federal Circuit (CAFC) issued a precedential ruling in Lynk Labs, Inc. v. Samsung Electronics Co., Ltd. affirming a final written decision by the Patent Trial and Appeal Board (PTAB) that invalidated Lynk Lab’s patent claims to alternating current driven LED lights and circuits. In so ruling, the Federal Circuit agreed with the PTAB’s determination that patent applications can be considered prior art printed publications as of the date of their filing, not their publication.

Pre-AIA Statutory Language Creates Special Prior Art Effect for Patent Applications

In November 2021, Samsung filed an inter partes review (IPR) proceeding to challenge the validity of Lynk Labs’ U.S. Patent No. 10687400, AC Light Emitting Diode and AC Led Drive Methods and Apparatus. It claims a lighting system with an LED circuit array having a plurality of LEDs connected in series and a driver providing a rectified AC voltage to the LED circuit array. The PTAB’s final written decision invalidated several claims of the ‘400 patent for obviousness based on a combination of prior art references including U.S. Patent Application No. 20040206970 (“Martin”). The Board dismissed Lynk Labs argument that Martin could not serve as prior art because, although filed prior to the ‘400 patent’s priority date, it wasn’t published by the U.S. Patent and Trademark Office until after that date.

On appeal, Lynk Labs argued that Martin could not qualify as a prior art printed publication because it was not publicly accessible. Although rules governing prior art printed publications under pre-America Invents Act (AIA) 35 U.S.C. §§ 102(a)-(b) require that the publication be publicly accessible prior to the effective date of the claimed invention, the Federal Circuit noted that pre-AIA Section 102(e)(1) included a special rule for published patent applications. This rule provides that patent applications published in accordance with 35 U.S.C. § 122(b) qualify as prior art if they were “filed in the United States before the invention by the applicant for patent.”

The Federal Circuit was unpersuaded by Lynk Labs’ contention that the statutory language of Sections 102(a) and (b), which refers to “printed publications,” was so changed in Section 102(e)(1)’s reference to “applications for patent, published under Section 122(b)” that the two terms must be completely distinct. The appellate court found it plain that the natural reading of those statutes indicated that Section 102(e)(1) was simply referencing a specific type of printed publication that becomes prior art as of the date it was filed.

Lynk Labs’ ‘Old Soil’ Case Law Arguments Predate Publication of Patent Applications

Provisions on “printed publications” as prior art have existed since the Patent Act was first established in 1952. Changes to the Patent Act in 1980, which established ex parte reexamination proceedings at the USPTO, introduced language on prior art “patents or printed publications.” Then the American Inventors Protection Act (AIPA) of 1999, which created inter partes reexamination, introduced Section 102(e)(1)’s rules on prior art published patent applications. Lynk Labs argued to the Federal Circuit that, by permitting reexaminations by “printed publications” and including separate rules for published patent applications, Congress brought up “old soil” from case law that excluded patent applications from qualifying as prior art printed publications.

“[M]uch of Lynk Labs’ ‘old soil’ case law predates when patent applications were published,” the Federal Circuit noted. As such, it wasn’t surprising that those cases did not address published patent applications. Although the Federal Circuit agreed that Congress did carry forth the requirement of public accessibility when crafting statutes using the term “printed publications,” temporal requirements in the statute govern when a printed publication must be publicly accessible to qualify as prior art. Section 102(e)(1)’s reference to Section 122(b)’s publication requirements created a different prior art effect for patent applications. Further, treating patent applications as prior art printed publications is consistent with Congressional purpose to restrict patentability challenges at the USPTO to printed documents.

Turning to the merits of the PTAB’s obviousness determination, the Federal Circuit dismissed several claim construction arguments from Lynk Labs. Holding that “a plurality of LEDs connected in series” can include LED circuits and not individual LEDs only, the Federal Circuit also found that claim language requiring that the LED forward voltage “matches” the rectified AC voltage does not require equivalency between the voltages. Several sections of the ‘400 patent’s specification disclose that those voltages match when the rectified AC voltage is less than the forward voltage of the LED series. Finally, although Martin disclosed use of an unrectified AC voltage, Samsung’s expert testimony to the PTAB established that a person of ordinary skill would have considered a rectified voltage as required for continuous light emission as matching input and output voltages in LED circuitry is now a matter of routine optimization.

Image Source: Deposit PHotos
Author: billperry
Image ID: 161261406