Signal Claims Are Not Patentable Subject Matter

In In re Nuijten (September 20, 2006) the Federal Circuit held that physical but transitory forms of signal transmission such as radio broadcasts, electrical signals through a wire, and light pulses through a fiber-optic cable are not directed to statutory subject matter.

Unlike the various allowed claims, which recited

• "A method of embedding supplemental data in a signal . . ."


• "An arrangement for embedding supplemental data in a signal," including "encoder means for encoding the signal," and


• "A storage medium having stored thereon a signal with embedded supplemental data,"

the rejected claims on appeal sought to cover the resulting encoded signals themselves. Claim 14 of Nuijten’s application was the only independent claim of the four rejected by the PTO. It read:

14. A signal with embedded supplemental data, the signal being encoded in accordance with a given encoding process and selected samples of the signal representing the supplemental data, and at least one of the samples preceding the selected samples is different from the sample corresponding to the given encoding
process.

Claims 22, 23, and 24 depended on Claim 14, respectively adding requirements that the embedded data be a watermark, that the signal be a video signal, and that the signal be an audio signal.

According to the decision by Circuit Judge Gajarsa,

[W]hile the claims are limited so as to require some physical carrier of information, they do not in any way specify what carrier element is to be used. . . . [S]ome physical form for the signal is required, but any form will do, so long as a recipient can understand the message—the nature of the signal’s physical carrier is totally irrelevant to the claims at issue. . . .

The claims on appeal cover transitory electrical and electromagnetic signals propagating through some medium, such as wires, air, or a vacuum. Those types of signals are not encompassed by any of the four enumerated statutory categories: "process, machine, manufacture, or composition of matter."

. . . The presence of acts recited in the claim does not transform a claim covering a thing—the signal itself—into one covering the process by which that thing was made. Since a process claim must cover an act or series of acts and Nuijten’s signal claims do not, the claims are not directed to a process.

. . . A transitory signal made of electrical or electromagnetic variances is not made of "parts" or "devices" in any mechanical sense. While such a signal is physical and real, it does not possess concrete structure in the sense implied by these definitions. No part of the signal—the crests or troughs of the electromagnetic wave, or perhaps the particles that make it up (modern physics teaches that both features are present simultaneously) is a mechanical "device" or "part." A propagating electromagnetic signal is not a "machine" as that term is used in § 101. . . .

The question of whether the claimed signals are "manufactures" is more difficult. They are man-made, in the sense of having been encoded, generated, and transmitted by artificial means. However, artificiality is insufficient by itself to render something a "manufacture." The Supreme Court has defined "manufacture" (in its verb form) as "the production of articles for use from raw or prepared materials by giving to these materials new forms, qualities, properties, or combinations, whether by hand-labor or by machinery." Diamond v. Chakrabarty, 447 U.S. 303, 308 (1980) (emphasis added) (quoting Am. Fruit Growers, Inc. v. Brogdex Co., 283 U.S. 1, 11 (1931)).5 The term is used in the statute in its noun form, Bayer AG v. Housey Pharms., Inc., 340 F.3d 1367, 1373 (Fed. Cir. 2003), and therefore refers to "articles" resulting from the process of manufacture. The same dictionary the Supreme Court relied on for its definition of "manufacture" in turn defines "article" as "a particular substance or commodity: as, an article of merchandise; an article of clothing; salt is a necessary article." Century Dictionary 326 (William Dwight Whitney ed., 1895) (emphasis in original).

These definitions address "articles" of "manufacture" as being tangible articles or commodities. A transient electric or electromagnetic transmission does not fit within that definition. While such a transmission is man-made and physical—it exists in the real world and has tangible causes and effects—it is a change in electric potential that, to be perceived, must be measured at a certain point in space and time by equipment capable of detecting and interpreting the signal. In essence, energy embodying the claimed signal is fleeting and is devoid of any semblance of permanence during transmission.6 Moreover, any tangibility arguably attributed to a signal is embodied in the principle that it is perceptible—e.g., changes in electrical potential can be measured. All signals within the scope of the claim do not themselves comprise some tangible article or commodity.7 This is particularly true when the signal is encoded on an electromagnetic carrier and transmitted through a vacuum—a medium that, by definition, is devoid of matter.8 Thus, we hold that Nuijten’s signals, standing alone, are not "manufacture[s]" under the meaning of that term in §101. . . .

. . . A signal comprising a fluctuation in electric potential or in electromagnetic fields is not a "chemical union," nor a gas, fluid, powder, or solid. Nuijten’s signals are not "composition[s] of matter."

Dissenting Circuit Judge Linn, on the other hand, would have concluded that the claim at issue is directed to a "new and useful" "manufacture."

Claim 14 is directed to a "manufacture" because the signal is, in the broad sense discussed above, an "article," "produc[ed] . . . for use from raw or prepared materials by giving to these materials [a] new form[]." See Chakrabarty, 447 U.S. at 308. Put differently, it is a product of human "art," or ingenuity; it is an application of technology to provoke some purposeful transformation in the real world. Any contrary conclusion must depend on a too-literal reading of either "article" or "material," neither of which appears in the statute, and neither of which any precedent—until today—has imposed as a limitation on the otherwise "expansive" scope of § 101. No matter what form the signal of claim 14 may take, it must involve "some physical carrier of information" that is created or manipulated through human activity, and that physical carrier must function "to convey information to a tecipient"—it must signal. See Majority Op. at 9–10.

Moreover, claim 14 is not directed to an abstract mathematical or scientific principle that fails to qualify as "new" under Funk Bros. and Benson. The claimed signal is artificial in character. The original input signal is "encoded in accordance with a given encoding process," causing it to undergo at least two transformations required by the language of the claim: first, "selected samples of the signal" are made to represent a second stream of "supplemental data"; and second, in order to reduce the impact of the first transformation, "at least one of the samples preceding the selected samples" is made to be "different from the sample corresponding to the given encoding process." These transformations may apply various laws of physics or mathematics, but they cannot be said to be mere representations or principles of them; neither one is a natural or pre-existing way in which two streams of data may combine, for instance. The signal itself is man-made.

The signal is also "useful" in a direct and specific way. The invention is directed to encoding and communicating data, and that is precisely what the signal does. Any information that it conveys is wholly distinct from the invention itself; the signal is an information carrier, not an attempt to claim information itself. Moreover—though my analysis does not rely on this fact—the claim construction that we unanimously adopt today requires that the signal have a physical manifestation that is directly linked to its purpose. Whether a smoke signal, a sound, or a set of encoded and perhaps encrypted bits traveling across a wireless network in the form of radio waves, a signal must be detectable in order to successfully signal anything. No intermediate steps, layers of interpretation, or speculative eventual uses separate the signal from the claimed purpose: simply put, the signal signals.

The correctness of these conclusions is supported also by the Supreme Court’s decision in a surprisingly analogous case from over 150 years ago, O’Reilly v. Morse, 56 U.S. (15 How.) 62 (1853). In Morse, Samuel Morse (of Morse code fame) was allowed a patent "for a process of using electromagnetism to produce distinguishable signs for telegraphy." Benson, 409 U.S. at 68 (discussing Morse, 56 U.S. (15 How.) at 112. As the Court later reiterated in 111). The Supreme Court disallowed Morse’s eighth claim, for the use of "electromagnetism, however developed for marking or printing intelligible characters, signs, or letters, at any distances," as the impermissible patenting of a scientific principle. As the Court later reiterated in The Telephone Cases, however, claims to specific uses of electromagnetism were patentable: "The effect of that decision [Morse] was, therefore, that the use of magnetism as a motive power, without regard to the particular process with which it was connected in the patent, could not be claimed, but that its use in that connection could." 126 U.S. 1, 534 (1888). In particular, the Court permitted Morse’s fifth claim, to the use of telegraphy to convey Morse code: "the system of signs, consisting of dots and spaces, and of dots, spaces, and horizontal lines, for numerals, letters, words, or sentences, substantially as herein set forth and illustrated, for telegraphic purposes." 56 U.S. (15 How.) at 86.

The "system" and constituent "signs" of Morse’s fifth claim are not "tangible articles or commodities." See Majority Op. at 16. Rather, the claim is directed to a signal—a particular way of encoding information so that it can be conveyed (in this case in the form of electrical impulses on a telegraph wire) in a useful manner at a distance. Morse’s signaling system conveyed certain important parts of a message—"numerals, letters, words, or sentences," but not lowercase letters, pictures, sound, etc.—under a particular set of constraints. Nuijten’s signal does the same—it conveys two streams of data, one primary stream and one lower-bandwidth "supplemental" stream—in a manner such that the supplemental stream is conveyed losslessly, and the primary stream is conveyed so as to minimize the effects of lost bits upon certain underlying encodings of data. Both Morse’s signal and Nuijten’s are "new" and "useful," and both are patentable.