Suppose that you want to obtain a patent for an invention and, in your claims of the patent application, you recite terms as a structure with functional language or means-plus-function language. What if this language requires an algorithm to carry out the function and you fail to disclose the algorithm in your patent application? Can the patent claims be held indefinite for failing to disclose the algorithm? The answer may be YES!
Under 35 U.S.C. § 112, ¶ 6, “[a]n element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.”
To determine whether § 112 ¶ 6 applies to a claim limitation, a court must inquire “whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure.” Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1349 (Fed. Cir. 2015). If the limitation uses the word “means,” there is a rebuttable presumption that § 112 ¶ 6 applies. Id. at 1348-49. If not, there is a rebuttable presumption that the provision does not apply. Id. The “presumption can be overcome and § 112 para. 6 will apply if the challenger demonstrates that the claim term fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function.” Id. at 1348 (quotations and brackets omitted). Failing to disclose adequate corresponding structure renders the claim indefinite. Id. at 1352.
In the recent case of Rain Computing, Inc. v. Samsung Electronics America, Inc., 989 F.3d 1002 (C.A.F.C. 2021), Rain Computing, Inc. (“Rain”) sued Samsung Electronics America, Inc. (“Samsung”) for infringement of certain claims of U.S. Patent No. 9,805,349 (“the ‘349 patent’). The ‘349 patent was directed to delivering software application packages to a client terminal in a network based on user commands. Claim 1, which is a method claim and representative of the asserted claims, had the claim limitation of “a user identification module configured to control access of said one or more software application packages”. In the Rain case, the appellate court had to determine whether the term “user identification module” was a mean-plus-function term. Because the terms “module” and “user identification” did not provide any indication of structure, the appellate court looked to the specification of the ‘349 patent to determine the structure. The appellate court found that the specification of the ‘349 patent did not even use the term “user identification module” or impart any structural significance to the term. Thus, the court held that the term “user identification module” was a means-plus-function term subject to § 112 ¶ 6.
Next, the appellate court had to identify the structure in the specification that was linked to the function to “control access” by the user identification module. In the past, the court has held that, if the function is performed by a general-purpose computer or microprocessor, the specification must disclose the algorithm that the computer performs to accomplish that function. Aristocrat Techs. Austl. Pty Ltd. v. Int’l Game Tech., 521 F.3d 1328, 1333 (Fed. Cir. 2008). However, “in the rare circumstances where any general-purpose computer without any special programming can perform the function … an algorithm need not be disclosed.” Ergo Licensing, LLC v. CareFusion 303, Inc., 673 F.3d 1361, 1365 (Fed. Cir. 2012). For means-plus-function terms “in which the disclosed structure is a computer, or microprocessor, programmed to carry out an algorithm,” the court has held that “the disclosed structure is not the general purpose computer, but rather the special purpose computer programmed to perform the disclosed algorithm.” WMS Gaming, Inc. v. Int’l Game Tech., 184 F.3d 1339, 1349 (Fed. Cir. 1999).
In the Rain case, the parties agreed that the function of the “user identification module” was “to control access to one or more software application packages to which the user has a subscription”. The lower court found that the structural examples linked to the function of the “user identification module” was “computer-readable media or storage device[s]” (“a SIM card, an IC card, a flash memory drive, a memory card, a CD-ROM, and the like”). The appellate court found that these computer-readable media or storage devices “amounted to nothing more than a general-purpose computer”. See, e.g., HTC Corp. v. IPCom GmbH & Co., KG, 667 F.3d 1270, 1280 (Fed. Cir. 2012) (the disclosed “processor and transceiver amount[ed] to nothing more than a general-purpose computer”). The appellate court also found that “control[ling] access to one or more software application packages to which the user has a subscription” requires more “than merely plugging in a general purpose computer.” Ergo Licensing, 673 F.3d at 1365. Further, the appellate court found that “some special programming, i.e., an algorithm, would be required to control access to the software application packages” and, without an algorithm to achieve the “control access” function, the appellate court held that the term “user identification module” lacked sufficient structure and rendered the claims indefinite.
Should the court have found that the claims were indefinite? In the Rain case, the patentee did not use the term “user identification module” in the specification or disclose structure corresponding to the “user identification module, thereby allowing 112 ¶ 6 to apply. The patentee disclosed that the function of “controlling access” was carried out by “computer-readable media or storage device[s]”, which amounted to a general purpose computer. Since 112 ¶ 6 applied, either the patentee needed to disclose other non-general purpose computer structure to carry out the function of “controlling access” or an algorithm to carry out the function of “controlling access” by the computer-readable media or storage device. Because the patentee did neither, the appellate court could not find an adequate corresponding structure for carrying out the function of “controlling access” by the means-plus-function term “user identification module” and found the claims indefinite.
In summary, the court has held that when 112 ¶ 6 applies to a claim limitation, there must be a corresponding structure disclosed in the specification to carry out the function of the means-plus-function term or the claims will be held indefinite as lacking sufficient structure. However, if an algorithm is disclosed in the specification in combination with a structure to carry out or achieve the function of the means-plus-function term of the claim limitation, the claim will be difficult to invalidate under 35 U.S.C. § 112. Therefore, to avoid indefiniteness in claim limitations having means-plus-function terms, one should disclose an algorithm in the patent application to carry out the function of the means-plus-function terms to avoid the claims being held invalid by a court.