Chapter 8: Patent Protection of Software:
Statutory Subject Matter in the
Supreme Court and the Federal Circuit

C. Statutory Subject Matter in and
After 1994, the Year of the Algorithm
(Continued — Third Section)

In re Trovato
United States Court of Appeals for the Federal Circuit
42 F.3d 1376 (Fed. Cir. 1994)(Trovato I),
vacated en banc, 60 F.3d 807 (Fed. Cir. 1995)(Trovato II)

Before Nies, Michel and Schall, Circuit Judges. Nies, Circuit Judge.

Trovato appeals decisions of the PTO Board of Patent Appeals and Interferences (board). The board affirmed the rejection of claims pending in U.S. Patent Applications, the ’024 application and the ’303 application, for lack of statutory subject matter under 35 U.S.C. § 101. Finding no reversible error in the board's decision, we affirm.

I. The Claimed Invention

The problem of finding the shortest distance between two points is a recurring one, and is of particular interest to students of the computer science field known as graph theory. Trovato's inventions work within this area, attempting to solve the “shortest path problem” by finding the optimal path between two locations, whether in terms of distance, cost, capacity, time or other criteria. The inventions model possible object movements in the real world — the “physical task space” — by a graph called a “configuration space.” Each node of the graph represents a discrete state, or set of conditions, such as location or orientation. Edges connect the graph nodes and indicate the cost of transferring from one state to another.

The configuration space is stored in a “data structure.” Although Trovato does not define this term, the specification makes clear that the data structure arranges various information needed to solve the shortest path problem. The data structure thus includes known information, such as the number of states in the configuration space, a “metric” providing the transition cost to any neighboring state, and the location of obstacles and goals in the configuration state. The data structure also accounts for data which Trovato's invention must calculate, including the optimal transition cost from one state to another, and the orientation, or next state on the path toward the nearest goal state.

The invention Trovato describes in the '303 application determines the most efficient path between states in the configuration space by propagating “cost waves,” a process also known as “budding.” Initially, the cost and direction of movement to the goal state from any particular state are unknown. The budding process calculates a value representing the cost of movement to the goal state for each possible state, as well as the direction to the goal state. Starting with the goal state and working outward to the remaining states, each neighboring state is explored in successive “waves,” ultimately indicating the lowest cost path from the initial state to the goal state, leading through a number of intermediate states. The '024 application describes an invention which improves upon the budding process described in the '303 application.

Method claim 1 of the '303 application is representative:

1. A method for determining motion of an object comprising the steps of:

a) storing a configuration space data structure representing a physical task space, the configuration space data structure including representations of the object and its environment; and

b) propagating cost waves, in the configuration space data structure, to fill the configuration space data structure with cost values according to a space variant metric.

Claim 33 is a representative apparatus claim of the application:

33. Apparatus for planning a least cost path comprising:

a) means for storing a discretized representation of a physical task space;

b) means for assigning at least one respective cost to at least one neighboring position of any given position, based on

    i) a cost assigned to the given position; and

    ii) a measure which varies according to position within the discretized representation, so that a least cost path from the neighboring position to the given position is established;

    c) means for starting the assigning means at a first position of known cost;

d) means for causing the assigning means to iterate, so that all positions within the discretized representation are assigned respective costs, in waves propagating outward from the first position; and

e) means for identifying a least cost path between two positions in the discretized representation based on the respective costs.

The examiner rejected the claims as being directed to nonstatutory subject matter under § 101 after applying the so-called Freeman-Walter-Abele test. This court has followed our predecessor court on this issue, and has summarized its methodology as follows:

It is first determined whether a mathematical algorithm is recited directly or indirectly in the claim. If so, it is next determined whether the claimed invention as a whole is no more than the algorithm itself; that is, whether the claim is directed to a mathematical algorithm that is not applied to or limited by physical elements or process steps.

The examiner reasoned that the claims, at least indirectly, recited a mathematical algorithm in that Trovato's claimed steps such as measuring transition costs, propagating cost waves and assigning costs values were all mathematical functions. Applying the second part of the Freeman-Walter-Abele test, he individually considered each claim and concluded that the claims did not involve physical structure or process steps beyond insignificant data-gathering steps or post-solution output, following Grams and Flook. Trovato appealed the rejection to the board, where the examiner's rejection was sustained except as to claims 24–26. The board reversed the examiner's rejection of claims 24-26, on the grounds that the claims recited sufficient physical structure. (Claims 24-26 recite apparatus such as a building emergency alarm system and an electronic map, and name objects to be moved such as an emergency vehicle, a person trying to exit a building, and a person trying to find a route in a new area.)

Representative method claim 1 of the '024 application provides:

1. A method for planning a path for an object to follow in a physical task space in which there has been a change in conditions comprising the steps of:

a) starting from an initialized configuration space data structure representing the physical task space, the configuration space data structure storing signals representing the object and its environment;

b) receiving signals indicating the change in conditions;

c) identifying the perimeter of a region in the configuration space data structure which is affected by the change in conditions;

d) propagating cost waves in the configuration space data structure from the perimeter to update the signals stored in the configuration space data structure; and

e) providing parameter signals based on the updated direction arrows [sic, signals], the parameter signals being usable by the object to follow the path.

Representative apparatus claim 41 of the '024 application provides:

41. Computer apparatus for planning a path for an object to follow in a physical task space in which there has been a change in conditions comprising:

a) means for storing a configuration space representing the object and its environment;

b) means for receiving signals indicating the change of conditions;

c) means for identifying a perimeter of a region in the configuration space which is affected by the change in conditions;

d) means for propagating cost waves from the perimeter by updating the configuration space, within the means for storing, to fill the configuration space with an updated representation corresponding to the change in conditions; and

e) means for supplying parameter signals based on the updated configuration space, the parameter signals being usable by the object to follow the path.

The same examiner who considered the '303 application rejected the claims of the '024 application, offering the same analysis under Freeman-Walter-Abele. The board upheld the rejection.

II. The Method Claims

We consider first the method claims of the '303 application and the '024 application. Trovato argues that neither element of the Freeman-Walter-Abele test is met.

We are unconvinced by Trovato’s argument that the claims of the applications do not recite a mathematical algorithm. Although the claimed process is not expressed in terms of a mathematical formula, application of the Freeman-Walter-Abele test is more refined than this simple determination. Our precedent also recognizes that “[w]ords used in a claim operating on data to solve a problem can serve the same purpose as a formula.” Grams. Here, the budding process described in each claim calculates a numerical transition cost, adds the transition cost to a previously computed sum of the costs to the goal state, and compares the sums for different states within the configuration space. Importantly, any number of vastly differing aspects of the physical task spaceincluding obstacles, terrain features such as slopes or slick surfaces, and danger to the moving object are represented abstractly, through a numerical value. The claims describe a systemic way of examining this data, which at every turn involves arithmetic operations manipulating numbers. We thus conclude that Trovato's method claims indirectly recite a mathematical algorithm.

Under the second part of the Freeman-Walter-Abele test, the court must “determine what the claimed steps do, independent of how they are implemented.” Unlike the invention claimed in Diehr, the specifications involved here provide no grasp of any underlying physical process. Although cursory references to such diverse apparatus as robots, dynamic emergency exit routes and electronic maps are present, no computer architecture is provided, no circuit diagram is revealed, and no hardware at all receives more than a brief mention. Indeed, the specifications note the inventions' “general applicability to numerical methods” and seek to describe them “[f]rom a mathematical point of view.” When questioned during oral argument before this court, counsel for Trovato admitted that neither specification includes a hardware enablement of the claimed invention. Instead, the entire disclosure consists of flow charts and program code computing the least cost path from starting to goal states based upon the data in the configuration space. We therefore conclude that Trovato claims nothing more than the process of performing a numerical calculation. Simply stated, viewing the claims absent the algorithm, and as a whole, no statutory subject matter is present.

Although some of Trovato's claims describe an electronic readout of the computed data, it is well-established that mere post–solution display does not render patentable a mathematical algorithm. As our predecessor court noted in Walter, “[i]f § 101 could be satisfied by the mere recordation of the results of a nonstatutory process on some record medium, even the most unskilled patent draftsman could provide for such a step.” Nor do Trovato's applications describe inventions which manipulate physical qualities, as with the inventions held to fall within statutory subject matter in cases such as Arrhythmia (analyzing electrocardiographic signals).

Trovato's applications fail even to explain how the claimed inventions actually employ the numbers derived to control movement. Although the inventions likely employ techniques known to the art to move an object along the lowest cost path it calculates, the absence of even a cursory description of how the computed values are implemented further indicates that the claimed methods comprise only numerical manipulation. Much like the application in Grams, “[t]he specification does not bulge with disclosure” regarding this crucial physical step, and instead focuses exclusively upon the mathematical calculations performed by the invention. We must conclude that the felt meaning of the claim is directed wholly toward an unpatentable mathematical algorithm.

For the purposes of the determination of statutory subject matter, we find these claims scarcely distinguishable from those before the Court in its recent decision in Warmerdam. In Warmerdam, this Court held that claims reciting a method for creating a data structure which controlled the motion of objects did not constitute patent eligible subject matter. Citing the difficulties in determining the proper boundaries of the nonstatutory category of mathematical algorithms, Warmerdam did not proceed by employing the latter term. The court instead reasoned that the claimed method was nothing more than the manipulation of abstract ideas, rather than speaking of a mathematical algorithm.

As in Warmerdam, Trovato's claims operate merely in the domain of abstract ideas. The methodical application of arithmetic operations to data placed within a numerical configuration in order to determine the least cost path through a mathematically structured graph amounts only to a generality or disembodied concept, outside the subject matter listed in § 101. Without further application or connection to a technical art, we cannot say that Trovato's claims pass muster under the alternative analysis of statutory subject matter expressed in Warmerdam.

We conclude that the board did not err in sustaining the rejections of the method claims.

III. The Apparatus Claims

The remaining claims of the '303 and '024 applications recite some sort of apparatus in the preamble. The apparatus claims essentially follow the format of the earlier method claims, although Trovato employs two additional drafting mechanisms. First, the preamble recites the term “apparatus.” Second, the term “means for” has been placed prior to the various claim limitations. (See generally Richard Stern, Tales From the Algorithm War, 18 AIPLA Q.J. 371 (1991).) Use of “means for” invokes 35 U.S.C. § 112 ¶ 6, which indicates that the PTO must construe the claims in light of the disclosed means for performing the recited functions and the equivalents thereof. See In re Donaldson, 16 F.3d 1189 (Fed. Cir. 1994) (in banc). Although Donaldson had not yet been decided when the board reached its decisions regarding these applications, it nonetheless applied § 112 ¶ 6 to both applications. It did so under the guidance of our earlier holdings in Arrhythmia and Iwahashi, which reached the same result in the context of § 101. At oral argument, counsel for Trovato agreed that the Donaldson holding did not impact this appeal.

The use of different claim formats does not necessarily diminish the impact of § 101. Even though the claimed invention is a machine, we must nevertheless determine whether the claim recites a mathematical algorithm, and, if so, whether it preempts the use of the algorithm. In this case, the additional claim language employed in this second group of claims, viewed in light of the specification, is of no patentable significance.

Although Trovato's claims employ the term “apparatus” in the preamble, such language alone will not always amount to a structural limitation affecting the scope of a claim. This court has noted instead that:

No litmus test can be given with respect to when the introductory words of a claim, the preamble, constitute a statement of purpose for the device or are, in themselves, additional structural limitations of a claim. To say that a preamble is a limitation if it gives “meaning to the claim” may merely state the problem rather than lead one to the answer. The effect preamble language should be given can be resolved only on review of the entirety of the patent to gain an understanding of what the inventors actually invented and intended to encompass by the claim.

Similarly, in Abele our predecessor court noted:

The goal is to answer the question “What did applicants invent?” If the claimed invention is a mathematical algorithm, it is improper subject matter for patent protection, whereas if the claimed invention is an application of the algorithm, § 101 will not bar the grant of a patent.

In answering that question, [e]ach invention must be evaluated as claimed; yet semantogenic considerations preclude a determination based solely on words appearing in the claims. In the final analysis under § 101, the claimed invention, as a whole, must be evaluated for what it is.

Hence, the analysis requires careful interpretation of each claim in light of its supporting disclosure.

Our review of Trovato's application in its entirety indicates that they do not disclose a machine of any sort. We can discern no disclosed apparatus provided in the specifications as suggested in the various claim preambles. Further, all the disclosed means are simply software instructions; no “structure” appears in the specification as required under § 112 ¶ 6. Although Trovato points to the “signals” drafted in some of their claims, indicating the electrical signals internally transmitted by a computer as part of its solution of the budding process, the mere noting of “signals” does not transform their inventions into statutory subject matter under the circumstances presented here. As noted in Bradley, 600 F.2d at 811-12:

It is of course true that a modern digital computer manipulates data, usually in binary form, by performing mathematical operations, such as addition, subtraction, multiplication, division, or bit shifting, on the data. But this is only how the computer does what it does. Of importance is the significance of the data and their manipulation in the real world, i.e., what the computer is doing. It may represent the solution of the Pythagorean theorem, or a complex vector equation describing the behavior of a rocket in flight, in which case the computer is performing a mathematical algorithm and solving an equation. [Emphasis in original.]

As with the hypothetical vector equation suggested in Bradley, Trovato's claims do no more than solve a mathematical algorithm. We can only conclude that Trovato's claims, as was the claimed invention in Walter, 618 F.2d at 769, are “drafted in illusory apparatus format.”

Our result here comports with our recent decision in Alappat. Although the claims of the inventor in Alappat were also drafted in means format, unlike the disclosure here, his application disclosed a specific hardware embodiment. There, we extensively relied upon the hardware listed in the specification, including arithmetic logic circuits, barrel shifters and a read only memory in reaching the result that the claimed invention constituted patent eligible subject matter. Specific note was also made of the combination of claimed elements from which the inventor formed a machine. As we have noted, however, a search through Trovato's application for the combination of similar apparatus is unavailing. The use of an apparatus claim format in this fashion is precisely the sort of “guise” recognized in Alappat, and the cases cited therein.

Other than noting the preamble terminology and the use of a means-plus-function claim format, Trovato's remaining argument regarding the patentability of their claims concerns the discipline of computer science itself. Trovato argues that the board's result is unjust because Trovato made a useful, novel and nonobvious contribution to the field of computer science. Trovato further contends that scientists working in the field of computer software are not less worthy of obtaining patent protection for their inventions than technologists in more traditional fields.

To the contrary, we have no reason to doubt that Trovato has made a contribution in the field of graph theory. Ingenuity and utility, however, have never been sufficient in themselves to garner patent protection. See Diehr (“This Court has undoubtedly recognized limits to § 101 and every discovery is not embraced within the statutory terms”). As the “basic tools of scientific and technological work,” Benson, mathematical calculations per se remain outside the sphere of patent protection. The presence of patent eligible subject matter must always be determined upon the individual facts of each case. The application in this case fails to meet the statutory standard.


Trovato does not claim to have invented a new kind of computer which the recited mathematical algorithm controls. Nor does Trovato claim that the recited mathematical algorithm has been combined with a new memory controlling a computer known to the art. Putting Trovato's claims in their most favorable light, the most they provide is a systematic way in which to compute a number representing the shortest path. A new way to calculate a number cannot be recognized as statutory subject matter. We thus conclude the board properly rejected the claims for lack of statutory subject matter under § 101. The decisions of the board are therefore affirmed.

Vacatur On Petition for Rehearing

Before Archer, Chief Judge, Rich, Nies, Newman, Mayer, Michel, Plager, Lourie, Clevenger, Rader, Schall, and Bryson, Circuit Judges. Order for the court filed by Chief Judge Archer; Circuit Judges Newman and Mayer concur in result; Circuit Judge Nies filed a dissenting opinion, in which Circuit Judge Michel joins.


Per Curiam:

Trovato seeks rehearing en banc of the appeals from decisions of the PTO board. Trovato challenges the board's affirmance of the rejection of Trovato's patent claims for lack of statutory subject matter under 35 U.S.C. § 101 (1988). Since the challenged board decisions, this court en banc has decided In re Alappat, providing further guidance on § 101. Alappat held that “a computer operating pursuant to software may represent patentable subject matter, provided, of course, that the claimed subject matter meets all of the other requirements of Title 35.” See also In re Lowry. The PTO has also recently proposed new guidelines for the examination of applications like Trovato's. See Request for Comments on Proposed Examination Guidelines for Computer-Implemented Inventions, 60 Fed. Reg. 28,778 (June 2, 1995). Consistent with Alappat, the proposed guidelines direct patent examiners to apply all of the requirements of Title 35 when examining applications claiming computer software instead of rejecting such applications under § 101.

On consideration of the combined petition for rehearing and suggestion for rehearing in banc,

It is ordered that the combined petition for rehearing and suggestion for rehearing en banc is accepted; that the judgment of this court entered on December 19, 1994 is vacated; and that the opinion accompanying the judgment, In re Trovato, 42 F.3d 1376 (Fed. Cir. 1994), is withdrawn.

It is further ordered that the decisions of the board are vacated, sua sponte, and the case is remanded for reconsideration in light of Alappat and any new guidelines adopted by the PTO for examination of computer-implemented inventions.

Nies, Circuit Judge, dissenting, with whom Michel, Circuit Judge, joins.

The majority's action is unconventional. Acting on a combined petition for rehearing and suggestion for rehearing en banc, the majority vacates the board decisions and the Federal Circuit panel decision affirming the underlying board decisions, and remands to the board. Yet, neither Trovato nor the PTO ask for a remand. No reasons are stated for the vacaturs. I must respectfully dissent from this order.

What message does the court's vacatur of the panel opinion send to the board? That the claims are statutory? Certainly not. The result of this order is simply that Trovato's application will stand before the board for review of the examiner's § 101 rejections. Furthermore, what message does the court's vacatur of the board decision send to the board? Was its analysis of precedent wrong, or is our prior precedent jettisoned along with the panel's opinion in this case?

There has been no official change in the PTO's procedure for determining statutory subject matter. The order states that the board is to reconsider the case in light of “any new guidelines adopted by the PTO for examination of computer-implemented inventions.” Although guidelines have been proposed, the process has barely begun. Adoption of the guidelines is not on the immediate horizon. Is the majority ordering a stay of Trovato's application indefinitely until the new guidelines are issued, or can the board proceed without them? What if the PTO decides to revise or not to adopt the guidelines?

Even if new guidelines are adopted, they must yield to precedent from this court and the Supreme Court, i.e. the law on § 101. Neither this court nor the Supreme Court has addressed § 101 since the panel opinion was issued. The law has not changed. Remarkably, the majority states that the proposed guidelines are “consistent with Alappat.” Should statements regarding the propriety of any agency guidelines, let alone proposed guidelines, be made without the assistance of briefing and/or oral argument or analysis? The proposed guidelines do more than just “direct examiners to apply all of the requirements of Title 35.” For example, under the section titled “Procedures To Be Followed When Evaluating Computer–Implemented Inventions,” there are a number of “presumptions” about what does and does not constitute a statutory “process,” “machine” and “article of manufacture.” Where did these presumptions come from? It appears that the majority provides an advisory opinion endorsing the proposed guidelines.

The order also states that “the case is remanded for reconsideration in light of Alappat.” The order does not state that the panel opinion was contrary to any of this court's precedent, including Alappat. It is true that the language of Trovato's claims and Alappat's claims is alike, and that Alappat's claims were held to meet § 101 while Trovato's were not.

The similar words in these claims does not end the § 101 analysis. Both Trovato and Alappat opted to use “means for” language. According to § 112 ¶ 6, we must look to the specification to flesh out the claims. Under Alappat, the command of § 112 ¶ 6 applies to determinations under § 101. Alappat's specification, unlike Trovato's, disclosed specific structure for the particular “means” claimed. Trovato disclosed no structure but merely a mathematical formula. Thus, Alappat does not address the particular question here of whether Trovato's claims constitute statutory subject matter.

If the majority believes the panel opinion is in some way contrary to Alappat, or that the precedent relied upon in the panel opinion should be overturned, the court should so state with explanation for the benefit of others. This order does a disservice to the board, the bar, and this court.

I dissent.


1. After Alappat, Warmerdam, and Trovato I were decided, it was observed that harmonizing the decisions of the Federal Circuit in algorithm-related cases was a challenge:

The recent evolution of mathematical algorithm case law in the Federal Circuit may be characterized as illustrative of chaos theory, or at least some kind of devolution in which the predictability of outcome progressively decreases with time. At this point, as Federal Circuit Judge Newman has aptly remarked of the doctrine of equivalents, "interpretation . . . will continue to depend on the selection of the panel." That Alappat, the second of 1994's opinions, was decided en banc did not improve predictability. It is only fair to say that rulings became less predictable after Alappat than before, except when one knows the panel composition, whereupon predictability increases dramatically.

. . . By the same token, infringement and validity opinions of counsel will not be definite and reliable. Security of expectation and investment, for software innovators with software patents and for their competitors with potentially infringing products, will suffer.

. . . At the beginning of the year [1994], a long line of case law seemed to be converging toward some clear, albeit complex, rules for distinguishing patentable algorithm-using machines and algorithm-using processes from unpatentable algorithms. The en banc Alappat decision shattered any seeming consensus in Federal Circuit law, and three subsequent panel decisions showed irreconcilable differences among the members of the court. . . .

[Richard H. Stern, Solving the Algorithm Conundrum: After 1994 in the Federal Circuit, Patent Law Needs a Radical Algorithmectomy, 22 AIPLA Q.J. 167, 169, 208, 232 (1995).]

Trovato II, in July 1995, may have clarified the view in the crystal ball, even if the per curiam en banc opinion was an “unconventional action.” Did it?

2. Does Trovato II tell us that Trovato I was absolutely the Very Last Hurrah of the Freeman-Walter-Abele test? The Very Last Hurrah of § 101 in algorithm–related cases? Is it just § 103 and § 112 ¶ 1 from now on? Will Trovato II turn the PTO in software cases into a monkey with a rubber stamp marked APPROVED?

3. Trovato I complains that the specification does not bulge with disclosure (à la Grams), the way Alappat's specification did. Instead, it just uses block diagrams, flowcharts, and code, and does not even show a circuit diagram or architecture description for a 486 PC. But does Trovato II tell us that "bulging with (hardware) disclosure" is passé and that Alappat cannot successfully be distinguished on the basis of its hardware disclosure bulges? Yet, the majority opinion in Alappat kept harping on the two barrel shifters and the ALU as limitations providing concreteness and preventing preemption, even more so than Iwahashi's look-up ROM did. Surely, all that hardware emphasis in Alappat wasn't just part of what Judge Archer's dissent called a "charade." Was it?

4. Why did the Federal Circuit en banc overturn the Trovato I panel opinion with this cryptic per curiam order of vacatur? Why a vacatur instead of a new opinion, after argument, reversing and remanding the judgment of the board?

In re Beauregard
United States Court of Appeals for the Federal Circuit
53 F.3d 1583 (1995)

Archer, Chief Judge.

The Commissioner of Patents and Trademarks moves to dismiss Beauregard's appeal. Beauregard responds stating that vacatur or reversal of the Board of Patent Appeals and Interferences' decision and remand to the Board is the appropriate disposition. Beauregard requests that the remand order be issued as a precedential order.

Briefly, the Board rejected Beauregard's computer program product claims on the basis of the printed matter doctrine. Beauregard appealed. The Commissioner now states “that computer programs embodied in a tangible medium, such as floppy diskettes, are patentable subject matter under 35 U.S.C. § 101 and must be examined under 35 U.S.C. §§ 102 and 103.”

The Commissioner states that he agrees with Beauregard's position on appeal that the printed matter doctrine is not applicable. Thus, the parties are in agreement that no case or controversy present-ly exists.

Accordingly, it is ordered that the Board's decision is vacated and the case is remanded for further proceedings in accordance with the Commissioner's concessions.


1. Beauregard was IBM's test case on another way to claim an algorithm, a project of its then chief patent lawyer, Victor Siber. The claim format was: an article of manufacture comprising a storage medium (e.g., floppy diskette) encoded with machine–readable computer program code for carrying out an algorithm. The algorithm could be recited as a sequence of means for performing various mathematical functions or as the steps of performing them.

The particular algorithm involved in Beauregard was a way to fill polygons, a procedure relevant to computer-aided design, font generation, and other graphics applications. (The invention is described and the parties’ positions are summarized in Richard H. Stern, Solving the Algorithm Conundrum: After 1994 in the Federal Circuit, Patent Law Needs a Radical Algorithmectomy, 22 AIPLA Q.J. 167, 195–203 (1995).)

2. The board had held the claims unpatentable on two separate but related grounds§§ 101 and 103. The grounds were related because they both involved variations on the "printed matter" rule.

The § 101 argument is that a claim to a book, where it is conceded that books are old, and the only assertion of novelty is the new material printed in the book (or, here, new material encoded on a floppy diskette), is directed to nonstatutory subject matter. This point is like one made in the Diehr dissent, where Justice Stevens analyzes Flook as holding that a claim is not directed to the kind of invention covered by § 101 when the inventor concedes that nothing in the claim is new except for a new algorithm. This is also Judge Archer's point about the CD with a new song, in the Alappat dissent.

The § 103 argument is that no patentable weight can be given to the identity of the information in a book (or floppy diskette), if that is the only thing about the book that differs from the prior art. Rather, printed matter can be unobvious and thus patentable subject matter only if the printed matter interacts with the substrate (e.g., book or CD) in a novel and unobvious way. See In re Gulack, 703 F.2d 1381 (Fed. Cir. (1983).

After the board's decision, the Federal Circuit decided In re Lowry, which held that the printed matter rule (no patents for written texts, such as books) did not apply to machine-readable material, as distinguished from human-readable material. This made the PTO believe that the board's opinion was not defensible, insofar as it rested on the printed matter doctrine. Accordingly, the PTO sought to have the case remanded to the board so that the decision could be shored up. (How would you rewrite the theory of unpatentability. i.e., patent eligibility, here to avoid reliance on the printed matter doctrine?)

At least, that was what IBM thought the PTO was up to. IBM therefore opposed the PTO's remand motion, the first time the PTO made it. IBM argued that the PTO was hypocritical in asking for a remand on the purported grounds that it wanted to “reconsider the matter in the light of Lowry” since it “appear[ed]” that the rejection was inconsistent with Lowry. IBM argued in its brief that everyone knows that the PTO pays no attention to a Federal Circuit panel decision unless it is “a decision that the Commissioner happens to agree with.” IBM said that “appears” and similar words of qualification belied the PTO's sincerity, and that on any remand the PTO would just reject again, on a basis distinguishing Lowry and limiting it to its facts. And absent a more abject confession of error by the PTO, it would be unfair to IBM to remand (it would deprive IBM of the benefit of its test case). The Federal Circuit then denied the PTO’s motion without explanation.

The PTO then moved again for a remand, this time making the statement quoted in the Federal Circuit's order. The PTO also advised the court that it planned to issue new guidelines to examiners on how to process computer-related patent applications. This led to the Notice to which Trovato II refers. It also led to the Federal Circuit's granting the renewed motion for a remand, per the per curiam order shown above.

3. What does this background suggest about how the PTO interpreted the Alappat decision and (as Judge Nies’ dissent asked) what is the “message sent” in Trovato II?

Can you figure out what is going on here? Why didn’t the PTO tough it out on the remand and vacatur of Trovato, dig its heels in as to Beauregard, and (instead of the wimpy Guidelines) come up with another Notice like the one it wrote after Iwahashi – for example, articulating the damp-squibb interpretation of Alappat (it’s a rule just for a claim chock full of apparatus, like an oscilloscope hooked up to some barrel shifters, and it doesn’t apply to programmed microprocessors that just crunch numbers)?

Several different things were going on at the same time over different parts of an extended period. The mills of the PTO grind slowly. The appeals board takes years to dispose of an appeal. Then the Federal Circuit takes another two or three years for briefing, arguing, and decision. At least another three months pass while the determination is made whether to seek certiorari from the Supreme Court to the Federal Circuit. Thus, Alappat, Trovato I, Lowry, Trovato II, and Beauregard are layered and tiled on top of one another over several years and a change in Commissioners and other personnel. (President Clinton appointed as Patent Commissioner the chief lobbyist for the software publishers, who was a copyright lawyer, not a patent lawyer. The new Commissioner appointed as Solicitor [appeals lawyer chief] a non-PTO-career patent lawyer. Both appointees were proponents of strong software protection. Meanwhile, in the Justice Department responsibility for recommending appeals from reversals of PTO rejections of software patents shifted away from the Patent Section of the Antitrust Division, which had been a strong supporter of the PTO staff in resisting software patents, to the Patent Section of the Civil Division, which apparently had other concerns.) The apprehensiveness of the PTO about pressing for an appeal in Alappat, because of the supposed packing-the-board issue, and the unwillingness of the Solicitor General’s Office to seek review in Lowry, earlier in 1994, because it was a confusing and unsuitable vehicle, seemed wholly to enervate and dispirit the PTO by the time of Trovato II and Beauregard. It seemed time for the PTO to throw in the towel. The PTO for years after that stopped requesting that appeals to the Supreme Court be taken from adverse decisions in the Federal Circuit in software patent cases.

4. The PTO’s Examination Guidelines for Computer-Related Inventions and further, related PTO materials are set out in an appendix to chapter 8.

5. A floppy-disk type of claim was involved in Reiffin v. Microsoft Corp., 214 F.3d 1342 (Fed. Cir. 2000), but the court did not address the issue of claim format. The case was decided on the written description requirement of § 112 ¶1.

6. The George Washington University Law School’s Symposium on floppy-disc claims is available online, as well as in hard-copy form in 17 John Marshall J. of Comp. & Info. L. 1 (1998). Several of the articles and a student paper address floppy-disk claims.

Tutorial on Floppy–Disk Claims

After the issuance of the PTO’s software guidelines, counsel may find it appropriate to include “floppy-disk claims” in any algorithm-related patent application. This tutorial illustrates the drafting of such claims.

The hypothetical invention on which these claims is based is a system for writing and filling veterinary prescriptions that is designed to overcome the problems that the notoriously illegible handwriting of veterinarians causes. As explained in the specification (omitted here), many a sick cat has been hurried off to cat heaven because of a misread and therefore incorrectly filled prescription. A further problem that the system addresses is drugstores’ careless or otherwise inaccurate filling of prescriptions for pets, so that they receive the wrong medication, another cause of the unfortunate demise of many family pets.

The system addresses these problems in terms of two subsystems — one for prescribing, and one for filling, veterinary prescriptions. The first subsystem permits a veterinarian who cannot write legibly, but can manage a data entry device, to write a machine–readable prescription. The second subsystem permits at least partially automated filling of the prescription that the first subsystem produces, thereby decreasing the likelihood of providing the wrong medication.

A claim directed to the first subsystem (writing a machine-readable prescription), drafted in floppy–disk format, follows:

    1. An article of manufacture comprising a computer–readable storage medium which is physically configured by having been encoded with machine-readable computer program code for causing a computer to perform the following steps, said steps comprising part of a method for entering by computer means a prescription for a pet, said computer having access to a first memory, in which is stored alphanumeric and barcode data representative of at least one drug entity, said stored data including drug–entity barcode identity data representative of an identity of said drug entity:

      a. creating in a second memory a new prescription record including data representative of said pet's identity;

      b. upon registering a signal representative of computer indication of a veterinarian's selection of a drug entity to be prescribed for said pet, sending to said new prescription record a drug-entity signal representative of said selection;

      c. placing in said new prescription record a pointer to a storage location of, or else fetching from storage in said first memory and storing in said new prescription record, alphanumeric and barcode data representative of said drug entity, such data including drug–entity barcode identity data representative of identity of said drug entity; and

      d. causing a printer to print out from said new prescription record a printed-medium prescription on which is printed alphanumeric and barcode data representative of said drug entity and said pet's identity, said data including said drug–entity barcode identity data and optionally additionally including barcoded dosage data, barcoded veterinarian-identity data, and barcoded pet–identity data.

A claim directed to the second subsystem (filling the foregoing machine–readable prescription), drafted in floppy–disk format, follows:

    2. An article of manufacture comprising a computer–readable storage medium which is physically configured by having been encoded with machine-readable computer program code for causing a computer to perform steps comprising part of a method for filling by computer means a prescription presented as a print–medium prescription having printed thereon a barcoding B representative of a drug entity prescribed for a pet and optionally having printed thereon other prescription-related barcode data, said steps comprising:

      a. causing to be recorded in a local memory said barcode data printed on said print–medium prescription, whereby a prescription input record is provided in said local memory;

      b. comparing said barcoding B in said prescription input record with an inventory record in a local memory to determine whether said drug entity is in stock, and proceeding to the next step if and only if said drug entity is in stock;

      c. comparing said barcoding B with a container–barcoding B read from a drug-containing container, said container-barcoding B being representative of a drug entity contained in said container; and

      d. if and only if said barcoding B corresponds to said container-barcoding B:

        1. providing a signal authorizing a drug to be dispensed from said container to a vial; and

        2. causing a printer to print for said vial a label based on said prescription input record.

The foregoing claims are directed to steps for carrying out the procedure. They could also have been directed to means for performing the steps, and it is largely a matter of drafter's choice which format to use. The steps format is often simpler.

Presumably, these floppy–disk format claims will be preceded by claims to the method and apparatus (system) that the computer program code on the floppy disk will implement. The preparation of such claims is left as an exercise.


1. Suppose that operating system vendor Nanosoft infringed a floppy disk patent on “un-install” software owned by Diskscrape. Nanosoft licenses a hard disk manufacturer Quark to preload the operating system software to hard disks that Quark sells to computer manufacturers. Does Diskscrape have a claim only against Nanosoft? or also one against Quark, as a direct infringer of the floppy disk patent? Does Quark need to know of the infringement to be liable? If Discscrape were obliged to rely on a theory of contributory infringement, would it be obliged to prove Quark’s knowledge of the patent, or that it was comitiing infringement? See the Aro case in the Supreme Court. Do you see why companies such as IBM want floppy-disc claims to be patent eligible?

2. Several court of appeals decisions have held reverse engineering of copyrighted software to be fair use, at least when undertaken for purposes of establishing compatibility. But there is no comparable doctrine of fair use in patent law. (See Roche Prods., Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858 (Fed. Cir.), cert. denied, 469 U.S. 856 (1984).) When one engages in reverse engineering of software, one ordinarily procures on the open market a copy of the computer program to be studied, stores the computer program onto one's hard disk or other storage device, disassembles the computer program with another program thereby producing a modified version of the computer program, and repeatedly encodes (“saves”) the partial results of the process onto one's hard disk. In the course of this process, the reverse engineer will repeatedly “make” the subject matter of a floppy disk patent (if any) covering the computer program. If she does that without authorization, is it in violation of 35 U.S.C. § 271(a)?

3. A major justification urged for having floppy disk patents was that they dispense with the difficulties of proving the elements of contributory infringement. Under prior law, a software invention was claimed as a machine system or process. That meant that a direct infringer was ordinarily an end user, not a seller of software on a storage medium. Software sellers were only contributory infringers or active inducers of infringement, because they did not make, sell, or use the machine system or process; they just sold a floppy disk or the like. Accordingly, they could be held liable only if shown to have culpable knowledge of infringement. (See the Aro case, supra note 1.)

What effect does the acceptance of floppy-disk patents have on retailers of software? What effect on upstream vendors, such as Microsoft? When Stac sued Microsoft for infringing its compression software patents (on “Stacker”) by incorporating Stacker elements into MS-DOS 6's “Double Space,” Stac had to prove the elements of contributory infringement or active inducing. Stac did so and prevailed, see this news article, although Stacker as a product was destroyed in the marketplace, largely because of the infringement. Stac did not even try to sue large retailers of MS-DOS. It could not have shown the necessary state of mind. If Stac had had floppy disk patents, however, what could it have done?

Tutorial on Signal Claims

[The following tutorial is of academic interest only. The decision of the Federal Circuit in In re Nuijten, 500 F.3d 1346 (Fed. Cir. 2007), abrogated signal claims.]

A special kind of article-of-manufacture claim is directed to an intangible form of medium in which information is embodied — a signal, typically transmitted via the Internet. Several of the articles in the GWLS Symposium mentioned above discuss signal claims. Authors Scott A. Horstemeyer and Daniel J. Santos, in their paper presented at the GWLS Symposium, A New Frontier in Patents: Patent Claims to Propagated Signals, maintain that “[t]he new frontier after In re Beauregard is the ‘propagated signal’ claim — a claim directed to a manufactured transient phenomenon, such as an electrical, optical, or acoustical signal, that could further revolutionize the way communications and software companies protect their intellectual property.” Here, the computer-readable medium is an electronic signal propagated over the Internet — that is, sent from server to server over the Internet, and ending up at a user’s PC, where a browser puts it into useable form.

An early proponent of such claims was former PTO Solicitor Nancy Linck. See Nancy Linck and Karen Buchanan, Patent Protection For Computer-Related Inventions: The Past, The Present, and the Future, 18 Hastings Comm. & Ent. L. J. 659 (1996). The PTO Training Materials at that time (see appeared to recognize that signal claims can pass muster under § 101, but they were less enthusiastic and objected to their intangibility. They insist on tying the claims to something more physical and tangible than undulations of electromagnetic vectors in space — for example, by embedding them in a memory device. They pointed to Koo U.S. Pat. No. 5,568,202 as an example of an allowed signal claim. Koo’s claim 1 read:

An electronic reference signal in a system for minimizing the effects of ghosts occurring during the transmission and reception of a television signal over a communications path, wherein said reference signal is embodied in a processor readable memory, is non-cyclic, has a substantially flat frequency response within the bandwidth of said communications path and has a plurality of substantially uniform amplitude peaks over a time interval, and wherein a replica of said reference signal is transmitted as part of said television signal and is utilized by a decoder to derive coefficients which are used with at least one filter to remove said ghosts.

Koo initially presented this or a similar claim, without the language in boldface. The examiner rejected it and the Board affirmed. On appeal to the Federal Circuit, apparently by agreement of the parties the appeal was dismissed and the case was remanded to the PTO to permit Koo to amend his claims. Presumably, the agreed upon amendment was to incorporate the signal in a computer-readable memory — the boldface language shown above.

The Training Materials gave two examples of signal claims. The first was: An assembly of transmitted signals wherein said signals carry encoded instructions to be read by a receiver; said assembly of signals arranged to be transmitted to a receiver. The Training Materials asserted that this claim is unpatentable under § 101 because the signal or assembly of signals, per se, is intangible. The statement about “to be read by a receiver” was dismissed as a mere statement of intended use.

The second signal-claim example was: A reference signal containing an arrangement of information; said reference signal is embodied in a processor readable memory. The Training Materials stated that this claim may be acceptable since it is comparable to the data structure stored in a memory that In re Lowry approved. (Personally, I would say that this claim is defective, signal-claim issues aside, because of the format, with two complete sentence-like clauses separated by a semicolon. I and most other patent claim drafters would prefer this format: (a) put a “wherein” after the semicolon, or else say (b) A reference signal containing an arrangement of information, said reference signal embodied in a processor readable memory [no verb in second clause].)

The Linck article, and Horstemeyer et al. too, gave a different example, essentially in this form: A computer data signal embodied in a carrier wave, said signal comprising a code segment comprising XYZ. As the Training Materials seemed to insist, however, embodied in a carrier wave is not tangible the way stored in a memory is. At least, the latter is what In re Lowry seems to think is tangible, while the former seems to be the same (in terms of tangibility) as the signal, per se, to which the Training Materials objected. The Canadian IP Office, however, may be more lenient. It expressly approved a carrier wave type of claim in its November 2000 Draft Guidlines in its Examiners’ Manual. This claim was in the form: A computer data signal embodied in a carrier wave and representing instructions which, when executed by a processor, cause the processor to [do XYZ].

Does the difference create a problem? I doubt it. An Internet signal is going to be embodied in a processor readable memory — in a server and in the RAM of the user’s PC. Therefore, the claim drafter loses nothing of substance by failing to seize the opportunity to fight City Hall by way of insisting on a claim to a signal per se or to a carrier wave embodying or modulated by such and such a signal.

Signal claims have theoretical and practical advantages. Horstemeyer et al. tout the possibility of ensnaring unsuspecting infringers. They say that “[t]he propagated signal claim gives new meaning to the concept of an ‘innocent’ infringer by making direct infringers of those who merely communicate the infringing signal, without perhaps any infringing intention, knowledge of the infringement, and in many cases, virtually no control over the transmission.” They contemplate making guilty defendants of “any carrier of the signal or proprietor of the propagation medium, such as, for instance, an Internet service provider (ISP), a telephone company, users of bridges and routers, etc., because they all ‘make’ and/or ‘use’ the signal.” I would put all that in the category of, at best, theoretical advantage.

A more practical advantage is in respect to transnational transactions involving possible infringements. For example, suppose you have a business method patent on a financial method involving placing or processing orders over the Internet. I set up my operations at a server in the Cayman Islands and thumb my nose at you. I am not practicing your method claims in the United States. I have no infringing apparatus in the United States. I may be inducing persons in the United States to practice some steps of your method, but if some of the other steps of the claimed method are necessarily performed in the Cayman Islands, at my end, you may have a serious problem getting a court to hold that the claimed method (i.e., all of its steps) was used in the United States.

However, suppose that you have claims to signals (embodied in memory, if necessary) that I transmit to users in the United States or that they transmit to me (for example, signals corresponding to a subset of the steps of the method, which are adapted for use in the whole method). Those signals are inevitably going to be stored in memories in the United States (at servers and user PCs), and the signals are likely to be retransmitted within the United States between memories, as well. The proprietors of those memories and the U.S. transmitters of those signals are using the claimed signals and making the claimed signals (placing them into memory, too). Moreover, I would seem to be actively inducing the users and makers to use and make. Therefore, such signal claims may be a practical means for attacking transnational acts of infringement that might otherwise go without redress.

In late 2005, the PTO changed position and it and the PTO Board came out against signal claims on the ground that signals were intangible and therefore did not fit into any of the statutory classes of § 101.*

      * The PTO recently issued interim examination guidelines that characterize signal claims as non-statutory subject matter. The PTO argued that a signal is not a process, composition of matter, machine, or article of manufacture. The signal has “no physical structure” and does not “itself perform any useful, concrete, and tangible result” and therefore is a non-statutory natural phenomenon. See Interim Guidelines for Examination of Patent Applications for Patent Subject Matter Eligibility, 1300 OG 142 (November 22, 2005) (available at PTO Website): “These interim guidelines propose that such signal claims are ineligible for patent protection because they do not fall within any of the four statutory classes of Sec. 101. Public comment [wa]s sought for further evaluation of this question.”

Link to section D of chapter 8

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