The 2021 US Court of Appeals for the Federal Circuit decision in Rain Computing v Samsung has further soaked the slippery slope associated with a claim element being interpreted as a means-plus-function element invoking 35 USC § 112(f) (or pre-America Invents Act, 35 USC § 112, sixth paragraph) and then being held as indefinite for lack of adequate written description.
Rain Computing obtained US patent number 9,805,349 and sued Samsung for infringement. The patent is directed to delivering software application packages to a client terminal in a network based on user demands. The relevant portion in claim 1 recites: “Sending, to the user, a user identification module configured to control access of said one or more software application packages, and coupling the user identification module to a client terminal device of the user” (emphasis added).
The US District Court for the District of Massachusetts held the user identification module was a means-plus-function element invoking interpretation under 35 USC § 112, sixth paragraph, and determined the specification included an adequate description of this element and its functions. While the US Court of Appeals for the Federal Circuit agreed the claimed module was a means-plus-function element, the court disagreed the specification included an adequate description of the element and held the claim was indefinite.
In particular, the Federal Circuit indicated that after determining an element is a means-plus-function element, the specification must be examined to determine (1) the claimed function of the element; and (2) the structure linked to the claimed function.
The Federal Circuit stated the “user identification module” was a mean-plus-function element, because the term “module” is a black box type of recitation that does not impart any structure. The Federal Circuit also determined (1) the claimed function of the element was described in the specification as “controlling access to one or more software application packages to which the user has a subscription” and (2) the structure linked to the claimed function was a description of generic computer-readable media or storage devices (eg, a SIM card, a memory card, etc).
”It is essential to make sure the specification includes the structure and sufficient algorithms (flowcharts) performed by the structure.”
David Bilodeau
Bradford Fritz
The Federal Circuit reasoned this description amounted to nothing more than a description of a general-purpose computer.
The Federal Circuit also emphasised that for an adequate structure in this type of situation, there must be some type of algorithm disclosed in the specification for the general-purpose computer to perform. The court stated the patent held by Rain Computing did not include adequate algorithms (flowcharts) and corresponding descriptions and reversed the district court’s judgment.
Adequacy of Rain’s disclosure
Some may argue that the Federal Circuit’s decision in Rain Computing is incorrect and Rain’s disclosure does provide adequate structure for the claimed “user identification module”. The Federal Circuit acknowledged that one of the structural examples linked to the claimed “user identification module” in Rain’s specification is a subscriber identity module (SIM) card. In addition, an argument could be presented that the SIM card and corresponding use is well-known to those skilled in the art and has a sufficiently definite meaning.
Holding the claimed “user identification module” indefinite for lack of adequate structure in the disclosure requires viewing the disclosure in a complete vacuum. This narrow reading of Rain’s disclosure ignores what is well-known to those skilled in the art and appears to contradict the USPTO’s “Manual of Patent Examining Procedure” § 2164.05(A), which states: “The specification need not disclose what is well-known to those skilled in the art and preferably omits that which is well-known to those skilled and already available to the public.”
Arguably, a SIM card’s function for controlling access is well-known to those skilled in the art, and reciting an algorithm explaining how a SIM card controls access is not needed, in accordance with MPEP § 2164.05(A). Here, Rain even argued open-source code for implementing the claimed “user identification module” is readily available online and accessible by the public. Also, the SIM card controlling the access was not the indicated allowable feature in the claim.
Further, any inadequacy in Rain’s disclosure could have been cure by describing an algorithm specifying how the SIM card controls access to the software packages, as would be understood by one skilled in the art. For example, the specification could have included the description “a SIM card controlling access to the software packages by executing a GSM algorithm and providing a signed response based on a ciphering key” or possibly by reciting “a SIM card controlling access to the software packages by providing a valid user name and password authorised to access the software packages, in response to a challenge”.
Prosecuting strategies
To avoid a means-plus-function interpretation, patent prosecutors have for many years changed the term “for” to “configured to”. However, the Federal Circuit in Rain Computing indicated this type of amendment does not necessarily avoid a means-plus-function interpretation, especially when a nonce term such as “module” is involved.
In light of this decision in Rain Computing, at a minimum, nonce terms such as “module” and “unit” should be avoided. In addition, such changes still might not avoid an interpretation under 35 USC § 112(f), and thus the specification should be carefully reviewed for the appropriate algorithms. The specification must also be examined to determine (1) the claimed function of the element; and (2) the structure linked to the claimed function.
That is, because an interpretation under 35 USC §112(f) may be unavoidable, it is very important to ensure the specification includes structure examples, flowcharts and corresponding descriptions.
In addition, if an examiner indicates a term such as a processor, a controller, etc, is interpreted as a means-plus-function element, arguments can be presented these terms are well-known to those skilled in the art to have a sufficient definite meaning and should not be interpreted under 35 USC §112(f).
”The court stated the patent held by Rain Computing did not include adequate algorithms (flowcharts) and corresponding descriptions and reversed the district court’s judgment”
A further modifying structural adjective may also be added to the term, such as a hardware-embedded processor. However, even if a controller or a processor is interpreted as a means-plus-function element, the determined scope of the claim is probably not significantly narrowed because means-plus-function interpretations include equivalents thereof.
A controller interpreted under 35 USC §112(f) and equivalents thereof should be similar in scope to a controller not interpreted under 35 USC §112(f). Nevertheless, as shown in Rain, it is essential to make sure the specification includes the structure and sufficient algorithms (flowcharts) performed by the structure.
Summary
There is a very real danger in unintentionally invoking 35 USC § 112(f) and then having a court hold the claim to be indefinite for lack of adequate disclosure. That is, once 35 USC § 112(f) is invoked, only intrinsic evidence (examples in the specification) can be relied upon as providing adequate structure.
Note that this determination is likely to be made after the patent has been granted, so it is important for the patent prosecutor to address these issues before prosecution is completed.
David Bilodeau is a partner at BSKB. He can be contacted at: dab@BSKB.com
Bradford Fritz is an associate at BSKB. He can be contacted at: bfritz@BSKB.com
Images, from top: Shutterstock / Brian A Jackson, Sundry Photography
