Typhoon Touch v. Dell: Claims Saved From Aristocrat Invalidity But No Infringement Found

By Chris Reaves

A massive infringement suit against the major players in the touch-screen mobile market ended in the Federal Circuit, which confirmed that two patents required that a computer have specific software installed, not merely the capacity to run said software should it be installed.  In a small comfort to the patent holder, the Circuit also reversed a holding that certain patent claims were unsupported means-plus-function claims, finding that a textual description of the procedure involved qualified as an “algorithm” for Aristocrat purposes.


In 1988, prosecution began on a chain of patent applications that culminated in Patents No. 5,379,057 (‘057) and No. 5,675,362 (‘362), issued in 1995 and 1997 respectively.  Both patents disclosed a “portable, keyboardless computer” with components including “a touch-sensitive screen … configured for entry of responses” and an “application generator for generating [at least one] data collection application and for creating different functional libraries”.

Typhoon Touch Technologies, Inc., the present assignee of the patents, sued numerous producers of tablets and smart phones for infringement of the patents.  However, in examining the claims at issue, the district court found that some were invalid as indefinite, and regardless that none were infringed as construed.  It therefore dismissed the case, and Typhoon Touch appealed the dismissal to the Federal Circuit.

Ruling 1: Devices Must Be Configured to Perform Function In Order to Infringe

Typhoon first protested the district court’s decision that, in various means-plus-function terms, the allegedly infringing structure “must perform the recited function”.  Under the rule of Microprocessor Enhancement Corp. (520 F.3d 1367), Typhoon argued, it was sufficient that the structure could be configured or programmed to perform the function, and therefore devices without said programming could still infringe.  The Circuit panel was unmoved, stating that although Microprocessor did allow for infringement by a structure already capable of performing a required function, it did not reach one that first needed to be “specifically so programmed or configured.”

Additionally, the district court had interpreted “keyboardless” to have its ordinary meaning: “without a mechanically integrated keyboard.”  The specification stated that the device was “keyboardless in that it does not require a keyboard for use”, which according to Typhoon redefined “keyboardless” to mean it could take input without a physical keyboard even if it had one.  However, although the Circuit acknowledged that a patentee may change the ordinary meaning of a term in the specification, it found no evidence of that in the instant case.  To the contrary, the specification was full of criticism of the use of mechanical keyboards in general, and never once disclosed a device with an integrated keyboard.

The panel also found no importance in Typhoon’s argument that the district court “constru[ed] the claims in order to target the accused devices and demonstrate their non-infringement.”  Rather, it stated, “[I]t is not inappropriate for a court to consider the accused devices when construing claim terms, for the purpose of ‘claim construction’ is to resolve issues of infringement.”

The Circuit therefore upheld all constructions of the district court. As Typhoon conceded that its patents were not infringed under the district court’s construction, the panel also upheld the judgment of non-infringement.

Ruling 2: Software Means-Plus-Function Claims Require Only a Procedure

In a Pyrrhic victory for Typhoon, the Circuit reversed the decision of invalidity for three claims that included a “means for cross-referencing said responses…” The district court had held these to be indefinite under § 112 ¶ 2, finding no “algorithm” in the description to perform the function, as required for software means-plus-function claims by Aristocrat Technology (521 F.3d 1328).  However, the Circuit found the district court’s interpretation of “algorithm” too restrictive in the context of computing.  A step-by-step procedure was sufficient – computer code was certainly not required – and although the Typhoon patents did not disclose this procedure through a flow chart, a “prose” disclosure in the text of the description served the same purpose.

“[T]he amount of detail that must be included in the specification depends on the subject matter that is described and its role in the invention as a whole, in view of the existing knowledge in the field of the invention.”  Because the specification described the steps of the cross-referencing procedure in terms that “a programmer of ordinary skill” could implement, the Circuit found the claims were supported and reversed the district court’s holding of indefiniteness.  It was no “concession,” as the district court felt it was, that Typhoon admitted “the specific algorithm connoting the structure of the means for cross-referencing element is not explicitly disclosed in the specification.”

Post-Case Analysis

The Circuit’s requirement of specific configuration seems not only sound but necessary, at least in the context of hardware and software.  Modern computers are quite capable of being programmed to run any number of procedures.  Once one has a computer meeting the hardware elements of a claim, no matter how general those elements, one can always install the software elements later, but that should not make the computer alone an infringement.  Presumably, the software is part of what makes the patent patentable, or the prosecutor would have patented the hardware alone, so a valid construction should not effectively make the software elements moot.  (Of course, if the hardware itself is specially designed to run the software in question, contributory infringement principles apply even without a software installation.  But this assumes the hardware has no other uses, and here it did.)

The opinion did not even address an argument that Typhoon tried to emphasize during oral arguments: that the patent claimed priority back to 1988, when hardware capable of executing the software (now ubiquitous) was itself new and arguably inventive.  This issue was beside the point.  Typhoon did not patent the hardware itself; it patented the hardware combined with software (at minimum, the “application generator”).  Again, if it did so because the hardware by itself was not new and unobvious even in 1988, removing the software requirement would have been a gross misreading of what the Patent Office had granted.  If it did so because the prosecutors were too focused on the software and did not consider the potential of the hardware alone, this serves as a lesson to future prosecutors: always remember to claim pieces as well as the whole, if the pieces are also inventive.  One never knows for sure which pieces might be discarded and which might come to dominate the market.

In regards to the “keyboardless” definition, the lesson is simply to remember that CCS Fitness (288 F.3d 1359) asks you to “clearly” redefine terms if you plan to do so.  Do not count on a court to pick up on subtleties and make the inference you want; be explicit with language such as “we define the term X herein to mean…”  Alternatively, use more natural terminology in the first place, such as, in this case, “capable of keyboardless data entry.”

In an interesting aside, the Circuit endorses a court molding its construction around the defendant’s claims, or at least focusing on the most applicable elements.  This approach would mean that the construction of a claim may vary depending on its first alleged infringer.  Issue preclusion applies to Markman constructions, albeit inconsistently and not in all circumstances (see RF Delaware (326 F.3d 1255), which applies a regional circuit’s law of preclusion).  And invalidation of a claim is binding in all courts even if a different construction would have saved the same claim.  It may be wise, therefore, to consider where and how a patent’s boundaries will be tested before deciding which infringing device to sue over first.

As is often the case, even the patent owner’s victories show where it could have drafted a better patent.  As Typhoon stated in oral arguments, had the cross-referencing procedure disclosed in the description been converted to a figure or flow chart, “we wouldn’t be here.”  The attorney meant it as an argument in support of validity, but it’s also a warning to future prosecutors: next time, include the flow chart.  Sometimes, it is the difference between a procedure a skilled programmer can understand and one she can’t, and even if not, it helps the judge understand it.

The opinion is available at: http://www.cafc.uscourts.gov/images/stories/opinions-orders/09-1589.pdf

Oral arguments may be heard at: http://oralarguments.cafc.uscourts.gov/default.aspx?fl=2009-1589.mp3

Feature Comment: The Heightened Disclosure Requirement for Software Claimed Using Means-Plus-Function Limitations

By Gregory L. Clinton[1]


The question of whether a computer component discloses adequate structure for a corresponding means-plus-function claim limitation has been a recurrent issue in recent Federal Circuit jurisprudence, most recently in the cases of Blackboard Inc. v. Desire2Learn Inc., 91 U.S.P.Q.2d 1481, 1483 (Fed. Cir. 2008).  and Net MoneyIN Inc. v. VeriSign Inc., 88 U.S.P.Q.2d 1751 (Fed. Cir. 2008).    In both cases the specification of the patents at issue did not provide adequate support for means-plus-function limitations in the claims.  Although the use of means-plus-function claims has fallen out of favor in recent years, means-plus-function claims remain useful in some situations.  Accordingly, a brief discussion on what to include in a specification to ensure proper support for such claims may be helpful to avoid problems during prosecution or litigation


Both of the two cases previously mentioned, Blackboard and Net MoneyIN, revolved in part around whether the specification provided adequate support for particular mean-plus-function limitations.  In both cases, the specification was found not to provide adequate support because the specifications merely described a general purpose computer, without any corresponding “structure” to which the means-plus-function claims could be tied.  In Blackboard, the patent was directed toward an Internet-based educational support system.  Blackboard Inc. v. Desire2Learn Inc., 91 U.S.P.Q.2d 1481, 1483 (Fed. Cir. 2008).  The claim limitation at issue recited “means for assigning a level of access to and control of each data file based on a user of the system’s predetermined role in a course…”  Id. at 1490.  Blackboard argued that the corresponding structure was an “access control manager” disclosed in the specification, citing to a particular paragraph describing the access control manager in largely functional terms.  Id.

The district court disagreed, finding the specification lacking the necessary structure to support the “means for assigning”, and the Federal Circuit affirmed.  Blackboard at 1490.  The Federal Circuit found that the access control manager was nothing more than a “black box”.  Id.  The specification provided no insight as to how the access control manager carried out the disclosed functionality.  Id.  In particular, the specification did not describe the structure of the access control manager or explain the process by which the access control manager performed the disclosed function.  Id.

The Federal Circuit rejected Blackboard’s arguments that the disclosed access control manager could be any computer device or program that performs the function of access control.  Blackboard at 1491.  The Federal Circuit viewed the argument as an attempt to avoid the requirement to disclose the structure associated with the means-plus-function limitation.  Blackboard was attempting to avoid the “price” of the means-plus-function limitation (namely, the requirement to disclose the corresponding structure) by attempting to claim the structure in purely functional terms, without any limit imposed by a structure disclosed in the specification.  Id.  What is important, the Federal Circuit held, was the means for achieving the intended outcome, not a mere description of that outcome.  Id.

One of the cases cited in the Blackboard decision, Net MoneyIn, Inc.  v. Verisign, Inc., expanded on the requirements in the disclosure for means-plus-function claims and computer-related structures.  The limitation in that case was a “means for generating an authenticating indicia” as part of a recited “first bank computer”.  Net MoneyIn, Inc. v. Verisign, Inc., 88 U.S.P.Q.2d 1751, 1755 (Fed. Cir. 2008).  After concluding that the limitation was properly construed as a means-plus-function limitation, the Federal Circuit looked to the specification for the corresponding structure, and found only a description of a general purpose bank computer that could be programmed to perform the recited function.  Id

The Federal Circuit reviewed prior holdings that the structure disclosed in the specification must be more than simply a general purpose computer.  Net MoneyIN at 1755.  If the disclosed structure is a computer, then the disclosure must be directed not to the general purpose computer itself, but to the algorithm which the general purpose computer is programmed to perform.  Id.  The operation of the algorithm performed by the general purpose computer transforms the general purpose computer into a special purpose computer designed to perform the disclosed algorithm.  Id.  Thus, if the specification fails to disclose the algorithm performed by the general purpose computer to carry out the recited function, then the claim is invalid under 35 U.S.C. § 112 for failing to disclose the necessary structure corresponding to the means-plus-function limitation.  Id. at 1757.


The Federal Circuit’s decision in the Blackboard and Net MoneyIn cases relied on its prior decision in WMS Game Inc. v. Int’l Game Tech., which in turn drew upon the landmark State Street Bank and Alappat decisions.  The patent at issue in WMS Gaming was directed toward an improved slot machine.  WMS Gaming, Inc. v. Int’l Game Tech., 51 U.S.P.Q.2d 1385, 1387 (Fed. Cir. 1999).  In traditional mechanical slot machines, reducing the probability of winning required either increasing the number of reels in the machine or increasing the number positions in each reel, neither of which appealed to players.  Id. The patent at issue in the case disclosed an electronically controlled slot machine.  Id.  The reels in the machine served only to display the results selected by the electronic control system.  Id.  The control system randomly selects a number from a range greater than the number of positions on the reel, looks up the corresponding result in a mapping table, and controls the reels to display the selected result.  Id.

The claim term at issue recited “a means for assigning a plurality of numbers representing said angular positions of said reel, said plurality of numbers exceeding said predetermined number of radial positions such that some rotational positions are expressed by a plurality of numbers.”  The district court interpreted the term to refer to “any table, formula, or algorithm for determining correspondence between the randomly selected numbers and rotational positions of the reel.”  WMS Gaming at 1391.  The Federal Circuit, however, found this interpretation to be too broad.

The flaw in the district court’s construction, the Federal Circuit held, lay in the district court’s failure to limit the claim to the algorithm disclosed in the specification.  WMS Gaming at 13.  The Federal Circuit reasserted its opinion in Alappat that a general purpose computer programmed to perform a given algorithm in effect becomes a new computer.  The general purpose computer in effect becomes a special purpose computer performing the disclosed algorithm.  Id. (citing In re Alappat, 31 U.S.P.Q.2d 1545, 1558 (Fed. Cir. 1994)).  Thus, in the context of means-plus-function claims, the structure is not the general-purpose computer, but rather the special purpose computer programmed to carry out the disclosed algorithm.  Applying this construction to the “means for assigning” limitation, the Federal Circuit held the corresponding structure to be a processor programmed to carry out the algorithm disclosed in Figure 6 of the patent.

The algorithm was disclosed in the patent at issue in WMS Gaming in the form of a diagram illustrating the operation of the algorithm.  However, patent applicants can express the algorithm in a variety of ways.  The algorithm can be explained as a diagram (as in WMS Gaming), as a mathematical formula, as a flowchart, or in prose. See Finisar Corp. v. DirecTV Group, Inc., 86 U.S.P.Q.2d 1609, 1623.


The Federal Circuit’s justification for defining algorithms as the important element for computer-related structures corresponding to a means-plus-function limitation relies upon the concept that a general purpose computer performing a disclosed algorithm can be seen as a special-purpose computer programmed to perform the function.  From this premise, it follows that a special-purpose computer could also be used as a sufficient structure.  Instead of disclosing an algorithm and a general-purpose computer to perform the algorithm, a patent applicant can instead disclose a special-purpose computer as the corresponding structure for a means-plus-function limitation.  Such a disclosure could come in the form of, for example, a detailed circuit diagram or schematic of the individual components of the special purpose computer.  A patent applicant may find such an alternative useful in situations where the novelty or inventive aspect lies more in the structure of the component than in the algorithm to be performed.


Federal Circuit jurisprudence permits the algorithm to be disclosed in a variety of ways.  The algorithm may be disclosed by a flowchart, a diagram, a formula, or prose.  Finisar at 1623.  Several cases illustrate the variety of ways in which a patent can disclose the necessary algorithm to support a means-plus-function case.  For example, the algorithm in WMS Gaming was disclosed by a combination of prose description in the specification and a figure.  See U.S. Patent No. 4,448,419 at Fig. 6 and col. 4, line 55 – col. 5, line 5.

In Harris Corp. v. Ericsson Inc., the algorithm was disclosed in a flowchart and corresponding textual description.  Harris Corp. v. Ericsson Inc., 75 U.S.P.Q.2d 1705, 1714 (Fed. Cir. 2005) (citing to various portions of U.S. Patent No. 4,365,338, including a flowchart shown in Figs. 8A and 8B).  The Federal Circuit disagreed with the district court’s finding that the recited “time domain processing means” corresponded to the disclosed “symbol processor”, because the symbol processor did not incorporate a disclosed algorithm.  The Federal Circuit instead found the disclosed structure to correspond not only to the symbol processor (which in turn included a support processor and a fast array processor) but also to a data recovery algorithm performed by the support processor.  Id.  The data recovery algorithm was disclosed in the specification as a flowchart diagram and corresponding description.  SeeU.S. Patent No. 4,365,338 at Figs. 8A, 8B, and 9.

The knowledge of a person of ordinary skill in the art can also support a disclosed structure or algorithm.  The patent at issue in AllVoice Computer PLC v. Nuance Communications Inc. recited an “output means” as a part of a system to facilitate speech recognition.  AllVoice Computer PLC v. Nuance Communications Inc., 84 U.S.P.Q.2d 1886, 1891.  AllVoice’s patent was directed toward an interface that converted spoken words into a data format compatible for word processors.  Id. The specification disclosed a speech recognition interface which, as part of its functionality, received a translated word and output the word via a dynamic data exchange (DDE) protocol.  Id.  Expert testimony established that this protocol was well known to persons of skill in the art of Windows programming.  Id. Thus, the person of ordinary skill in the art would have been well apprised of a structure corresponding to the disclosed DDE protocol. 

The AllVoice decision contrasts with the Blackboard and Net MoneyIn cases discussed above.  In both cases, the patentee attempted to rely upon the knowledge of a person of ordinary skill in the art to support the disclosed structure, but of the three, only AllVoice succeeded in convincing the Federal Circuit.  The distinguishing feature lies in the  extent to which the parties relied upon the knowledge of the person of ordinary skill in the art.  The disclosures of the Net MoneyIN patent and the Blackboard patent contained no element or internal structure of the various components.  The components were simply “black boxes” that a person of ordinary skill in the art could have programmed to perform the recited function.  Compare Net MoneyIN, 88 U.S.P.Q. 2d at 1756 and Blackboard, 91 U.S.P.Q.2d at 1491.  However, the disclosure of the AllVoice patent described the structure of the component in terms that would be understood by a person of ordinary skill – namely, the DDE component, which was a structure known in the art for carrying out a particular function.  This provided enough structure to render the corresponding means limitation definite.


As can be seen in the above cases, patent application drafters should pay special attention to the specification if means-plus-function claims are to be used.  If computer components are to be disclosed as the structure corresponding to a means-plus-function, either the specific structure of the corresponding component(s) should be disclosed (i.e. a special-purpose computer), or the algorithm carried out by the corresponding component(s) should be disclosed.  The algorithm can be disclosed in a variety of ways, including flowcharts, written explanation, diagrams, mathematical formulae, or a combination of these.  By disclosing the algorithm and the particular components, the careful patent drafter can avoid the definiteness problems that arose in Net MoneyIN and Blackboard.

[1] Gregory L. Clinton is an associate at Stein McEwen, LLP.  The opinions in this article do not represent the official positions of Stein McEwen, LLP.

Federal Circuit Finds “Mechanism for Moving” to be Means plus Function Term

In Welker Bearing Company v. PHD, Inc., Case 2008-1169 (Fed. Cir. Dec. 15, 2008), the Welker Bearing Company (Welker) owns U.S. Patents 6,786,478 (‘478 patent), which issued on September 7, 2004, and 6,913,254 (‘254 Patent), which issued on July 5, 2005.  The ‘254 and ‘478 patents, which have identical specifications, are directed towards locating and clamping assemblies for use during welding, with both claiming pin clamps to securely hold an item while being worked upon or welded.  The pin clamps are topped with a locating pin inserted into holes in the item and clamping fingers extending from the pin clamp to secure the item to an annular ring on the pin clamp. Continue reading Federal Circuit Finds “Mechanism for Moving” to be Means plus Function Term

Means-Plus-Function Claims

Patents in suit may not be construed, under 35 U.S.C. §112, sixth paragraph, to disclose computer software as structure corresponding to claimed function if patents’ specifications do not clearly link or associate software with that function, since § 112 does not permit patentee to claim in functional terms unbounded by any reference to structure in specification, and since failure to clearly link or associate software with claimed function is also failure to meet § 112’s definiteness requirement.  The Federal Circuit held that the Federal District Court correctly found the corresponding structure for the “means for converting said plurality of images into a selected format” to be the VME bus based framegrabber video display board, and the computer video processor.  However, the Federal Circuit held that the district court erred by identifying software as an additional corresponding structure for this limitation.  There is nothing in the specification or prosecution history that clearly links or associates software with the function of converting images into a format.  A correct inquiry is to look at the disclosure of the patent and determine if one of skill in the art would have understood the disclosure to encompass software for digital-to-digital conversion and been able to implement such a program, not simply whether one of skill in the art would have been able to write such a software system.  (Medical Instrumentation and Diagnostics Corp. v. Elekta AB, 68 USPQ2d 1263, CA FC, 9/22/03).