The Federal Circuit provided its latest guidance with respect to prosecution disclaimer in K-fee System GMBH v. Nespresso USA, Inc., 2023 WL 8882383, — F.4th — (Fed. Cir. Dec. 26, 2023).  K-fee involved patents covering coffee-machine portion capsules that used a “barcode” to “prevent the capsules from being used in incompatible machines.”  K-fee, 2023 WL 8882383 at *1.  During claim construction, the district court found “that K-fee had ‘argued strenuously’ before the EPO [(European Patent Office)] for a particular ‘plain and ordinary meaning,’ which excluded ‘bit codes’—codes made up of two binary symbols” —from the plain and ordinary meaning of “barcode.”  K-fee,  2023 WL 8882383 at *2.  The key portion of the EPO record included statements made by K-fee to distinguish a particular piece of prior art referred to as the “Jarisch” reference.  K-fee,  2023 WL 8882383 at *2.  Based on its interpretation of K-fee’s EPO submission, the district court construed the plain and ordinary meaning of “barcode” as “a code having bars of variable width, which includes the lines and gaps,” but “does not include the type of bit code disclosed in Jarisch.”  K-fee,  2023 WL 8882383 at *2.

Based on this construction, Nespresso moved for summary judgment of non-infringement, arguing that “its accused products operated identically to the Jarisch capsules that K-fee had distinguished before the EPO in that both used a machine-readable code having only two binary symbols,” and therefore “did not meet the ‘barcode’ limitations of the claims.”  K-fee,  2023 WL 8882383 at *2.  In granting the motion, the district court “reiterated that bit codes using only two symbols could not be barcodes, placing particular weight on K-fee’s statement to the EPO that Jarisch discloses a ‘bit code,’ but not a barcode, because the barcode . . . is always constructed of bars having variable widths, and therefore contains more than only two binary symbols.”  K-fee,  2023 WL 8882383 at *2 (citations omitted).

K-fee appealed, arguing that the district court improperly narrowed the ordinary meaning of “barcode” as excluding codes using only two symbols (i.e. bit codes) by implicitly finding prosecution disclaimer based on K-fee’s statements to the EPO.  K-fee,  2023 WL 8882383 at *3.  According to K-fee, “its statements to the EPO did not meet the standard for disclaimer.”  K-fee,  2023 WL 8882383 at *3.  In response, Nespresso argued that the district court properly relied on “the prosecution history to clarify the ordinary meaning, not to narrow an otherwise apparent ordinary meaning” and, nevertheless, applying the standard required for disclaimer would lead to the same result.  K-fee,  2023 WL 8882383 at *3.

The Federal Circuit reviewed the EPO submissions, as a whole, and found in favor of K-fee.  “To act as its own lexicographer, a patentee must clearly set forth a definition of the disputed claim term other than its plain and ordinary meaning and must clearly express an intent to redefine the term.”  K-fee,  2023 WL 8882383 at *6 (citations and quotations omitted).  The EPO record showed that K-fee argued that an artisan defines “the term ‘barcode’ as a line code constructed of bars having variable widths,” and Jarisch did not meet this definition.  K-fee,  2023 WL 8882383 at *4.  Specifically, Jarisch discloses “a code whose messages are ‘formed of a succession of small rectangular surfaces’ that can encode two states, corresponding to 0 and 1.”  K-fee, 2023 WL 8882383 at *4 (citations omitted).  The Federal Circuit noted that K-fee’s point was that Jarisch “does not clearly reveal any bars of varying widths,” not that barcodes cannot be bit codes.  K-fee,  2023 WL 8882383 at *6.  Moreover, “the EPO itself concluded that it was ‘not evident’ that Jarisch discloses ‘a barcode having variable widths.”  K-fee, 2023 WL 8882383 at *6.  Accordingly, the Federal Circuit concluded “that K-fee did not act with the clarity required either to prescribe a new meaning for ‘barcode’ or to disclaim any portion of the apparent meaning,” such that barcodes cannot include bit codes.  K-fee, 2023 WL 8882383 at *6.

In addition, the Federal Circuit rejected Nespresso’s argument “that because K-fee’s statements were ‘repeated, unequivocal, and unambiguous,’ a conclusion of disclaimer is appropriate.”  K-fee, 2023 WL 8882383 at *7.  The Federal Circuit highlighted that “[e]ven if an isolated statement appears to disclaim subject matter, the prosecution history as a whole may demonstrate that the patentee committed no clear and unmistakable error.”  K-fee, 2023 WL 8882383 at *7.  The Federal Circuit reiterated that “the statements K-fee made about bit codes were not clear and, if anything, were decidedly ambiguous.  Taken as a whole, the prosecution history certainly demonstrates ‘that the patentee committed no clear and unmistakable disclaimer.’”  K-fee, 2023 WL 8882383 at *7.  “The only thing K-fee clearly distinguished before the EPO was Jarisch itself, which nowhere declares that its messages have bars of variable width.”  K-fee, 2023 WL 8882383 at *7.  Accordingly, the Federal Circuit reversed the district court and construed “barcode” as referring to “code messages consisting of a linearly arranged sequence of bars of visually non-uniform widths (or a coding system producing such messages).”  K-fee, 2023 WL 8882383 at *6.

K-fee serves as a valid reminder of the stringent standard for prosecution disclaimer and the importance of the context in which a patentee’s statements are made.  Practitioners should pay critical attention to the nuance and circumstances of a patentee’s statements, especially when asserting that a patentee’s arguments made to distinguish prior art amount to disclaimer.  Moreover, practitioners must view a patentee’s prosecution statements as a whole, and should be wary of isolated statements that are not representative of the prosecution history as a whole.

K-fee further highlights the Federal Circuit’s lack of consensus in how statements made during patent prosecution may be used in construing claim terms.  Some decisions hold that the prosecution history can narrow the meaning of a claim term only if the patentee “limited or surrendered claim scope through a clear and unmistakable disavowal.”  See, e.g., 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1322 (Fed. Cir. 2013).  The K-fee decision follows this approach.  Other decisions, in contrast, conclude that “even in the absence of a clear and unmistakable disavowal, . . . the prosecution history can be evaluated to determine how a person of ordinary skill would understand a given claim term.”  AstraZeneca AB v. Mylan Pharm. Inc., 19 F.4th 1325, 1335 (Fed. Cir. 2021) (citations omitted); see also Amgen Inc. v. Coherus BioSciences Inc., 931 F.3d 1154, 1159-60 (Fed. Cir. 2019) (concluding that argument-based prosecution-history estoppel applies when “a competitor would reasonably believe that the applicant had surrendered the relevant subject matter” even when the representation was not made to “secure allowance of the claim”); cf. Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1326 n.1 (Fed. Cir. 2003) (recognizing that the standard for prosecution disclaimer is the same as the standard for argument-based prosecution-history estoppel).  Given these conflicting pronouncements as to the appropriate standard, this issue is ripe for en banc or Supreme Court review.