Patents sometimes issue with typographical errors. Courts may correct “obvious minor typographical and clerical errors in patents,” even if it may structurally alter the patent claim. Novo Indus., L.P. v. Micro Molds Corp., 350 F.3d 1348, 1357 (Fed. Cir. 2003).

For example, in Ultimax Cement Mfg. Corp. v. CTS Cement Mfg. Corp., 587 F.3d 1339, 1352–53 (Fed. Cir. 2009), the court inserted a comma because a skilled artisan would have known that the omission of the comma was a mistake. Id. (without a comma, “both fluorine and chlorine must be present in the compound. A comma changes the possible makeup of the formula allowing for the presence of either fluoride or chloride or both, but not requiring the presence of both molecules.”)

Also, in Lemelson v. General Mills, Inc., 968 F.2d 1202, 1203 (Fed. Cir. 1992), the court inserted the word “toy” into a preamble reciting a “trackway” so that the claim would read as “trackway toy.”

Likewise, in I.T.S. Rubber Co. v. Essex Rubber Co., 272 U.S. 429, 441–43 (1926), the U.S. Supreme Court corrected “upper edge” to “rear upper edge” in a patent claim. Judicial correction is “not in any real sense, a re-making of the claim; but is merely giving to it the meaning which was intended by the applicant and understood by the examiner.” Id. at 443.

Legal Standard for Patent Correction

Correction is appropriate “only if (1) the correction is not subject to reasonable debate based on consideration of the claim language and the specification and (2) the prosecution history does not suggest a different interpretation of the claims.” Novo Indus., 350 F.3d at 1354.

The error must be “evident from the face of the patent.” Grp. One, Ltd. v. Hallmark Cards, Inc., 407 F.3d 1297, 1303 (Fed. Cir. 2005). In deciding whether a particular correction is appropriate, the court “must consider how a potential correction would impact the scope of a claim and if the inventor is entitled to the resulting claim scope based on the written description of the patent.” CBT Flint Partners, LLC v. Return Path, Inc., 654 F.3d 1353, 1359 (Fed. Cir. 2011).

Not Required to Guess

In CBT Flint, the claim at issue included the limitation “a computer in communication with a network, the computer being programmed to detect analyze the electronic mail communication sent by the sending party to determine whether or not the sending party is an authorized sending party or an unauthorized sending party” (emphasis added). Three possible corrections were: (1) delete the word “detect,” (2) delete the word “analyze,” or (3) insert “and” between “detect” and “analyze.” Id. at 1359.

“Because each of the three proposed reasonable interpretations would result in the same claim scope,” the court concluded that “a person of skill in the art would readily know that the meaning of the claim requires insertion of the word ‘and' between the words ‘detect' and ‘analyze.'” Id. One “was not required to guess which meaning was intended in in order to make sense out of the patent claim.” Id. at 1360.

Claim Interpretation is Not a Substitute for Correction

In contrast, the court in Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1374 (Fed. Cir. 2004), found that, for a patent directed to a process for making dough products, correcting or interpreting the claim language, “heating the resulting batter-coated dough to a temperature in the range of about 400° F. to 850° F,” to read as heating the dough “at a temperature in the range of” about 400° F to 850° F” was inappropriate. Even though it was undisputed that the dough “would be burned to a crisp” if heated to 400° F, the court held the plain language of the claim was clear and unmistakable. Id. at 1373–74. A court “may not redraft claims, whether to make them operable or to sustain their validity.” Id. at 1374.

The Court in Chef America, also pointed out that the “patentees made no attempt to have . . . an error corrected, . . . by action of the district court.” Id. at 1375.

Correcting “Case” with “Cover”

The Federal Circuit recently addressed the judicial correction of a U.S. Patent No. 6,926,544 (“the `544 patent”) in Pavo Solutions LLC v. Kingston Technology Co., Inc., No. 21-1834 (Fed. Cir. Jun. 3, 2022).

The claim was for a “flash memory main body included a rectangular shaped case” and a “cover . . . for pivoting the case with respect to the flash memory main body.” Because the case is a part of the flash memory main body (i.e., “a flash memory main body including a rectangular shaped case”), anything that pivots with respect to the case also pivots with respect to the flash memory main body.

The Court distinguished Chef America because the structural limitations of the `544 patent claims describe a cover that necessarily pivots with respect to the flash memory main body.

Furthermore, as written facially (i.e., the case pivoting with respect to a component of which it forms a part), the claim “did not make sense.” Chef America, on the other hand, described “a realistic but perhaps undesirable result, i.e., cooking dough to 400° F and burning it.”

The specification of the `544 patent also confirms the error in the claims by “describing a flash memory device with a pivoting cover, whereas in Chef America, nothing in the specification or the prosecution history suggested that the patentee meant for the dough to be cooked “at” 400° F rather than “to” 400° F.

The Federal Circuit affirmed that “pivoting the case with respect to the flash memory main body” in the patent claims could be corrected with respect to an obvious minor clerical error, namely that the claimed “case” should have been the “cover.”

The attorneys at Thomas P. Howard, LLC prosecute and litigate patents nationwide including in Colorado.