Patent claims are usually in the form of a series of specified elements and corresponding limitations, or more precisely noun phrases, following the description portion of the invention in a patent or patent application. The claims define, in technical terms, the extent of the protection conferred by a patent, or the protection sought in a patent application. Similar to the language in a deed for real property (i.e., land), the claims are to set out the "metes and bounds" of the intellectual property protected by the patent. They are of the utmost importance both during prosecution and litigation.

For instance, a claim could read:

• "An apparatus for catching mice, comprising a base member for placement on a flat surface, a spring member..."
• "A chemical for cleaning windows, comprising approximately 10–15% ammonia, ..."
• "Method for computing future life expectancies, the method comprising gathering personal data including X, Y, Z, ..."

A patent is a right to preclude others from making, using, selling or offering for sale the subject matter defined by the claims. In order to exclude someone from using a patented invention in a court, the patent owner, or patentee, needs to demonstrate that what the other person is using falls within the scope of a claim of the patent. Therefore, it is more valuable to obtain claims that include the minimal set of limitations that differentiate an invention over what came before, i.e. the so-called prior art. On the other hand, the fewer the limitations in a claim, the more likely it is that the claim will cover or "read on" what came before and be rejected during examination or found to be invalid at a later time for lack of novelty.

History

Patents have not always contained claims. In many European countries, patents did not contain claims before the 1970s. It was then often difficult (and subjective) to decide whether a product infringed a patent, since the sole basis to know the extent of protection was the description, in view of the prior art. Claims have been necessary parts of U.S. patent applications since the enactment of the Patent Act of 1836.¹

However, even among patent legal systems in which the claims are used as the reference to decide the scope of protection conferred by a patent, the way the claims are used may vary substantially. Traditionally, two types of claiming system exist:

• the central claiming system, according to which the claims identify the "centre" of the patented invention. The exact scope of the protection depends on the actual nature of the inventor’s contribution to the art in the concerned technology.
• the peripheral claiming system, according to which the claims identify the exact periphery, or boundary, of the conferred protection. In this system, the burden of drafting good claims is much higher on the patent applicant (or on his counsel). The applicant receives the protection he or she requested and almost nothing more, provided that the invention is new and non-obvious. This theoretically makes it easier for third parties to examine whether infringement may exist or not.

No patent system today is a purely either central or peripheral, but the system used in Germany and most of the other countries of continental Europe is considered more central than the system currently used in the United Kingdom, the United States, and especially Japan, which are more peripheral.^{citation needed} In recent years, Japan's system has become more peripheral,² while the system used in the United States has become less peripheral.^{3dubious – discuss}

Requirements and structure

The examples and perspective in this article or section may not represent a worldwide view of the subject. Please improve this article or discuss the issue on the talk page.

In most modern patent laws, patent applications must have at least one claim, which are critical defining elements of the patent and the primary subject of examination. In some patent laws however, a date of filing may be obtained for an application which does not contain any claim.⁴

Under the European Patent Convention (EPC), a claim must define the matter for which the protection is sought in terms of technical features. These technical features can be either structural (e.g. a nail, a rivet) or functional (e.g. fastening means).

A claim may include the following parts (the terminology and requirements may however significantly differ from one legislation to another):

• A preamble that recites the class of the invention, and optionally its primary properties, purpose, or field: "An apparatus..." "A therapeutic method for treating cancer..." "A composition having an affinity for protein X..." This preamble may also reference another claim and refine it, e.g., "The method of claim 1..." (See "dependent claim" below.). However, under the European Patent Convention, the preamble has a different meaning. In an independent claim, it is everything which precedes the expression "characterized in that" or "characterized by".⁵

• A "transitional" phrase that characterizes the elements that follow. The phrase "comprising" is most often used and (under some patent laws) preferable, as it means "having at least the following elements..." The phrases "consisting of," "consisting essentially of," etc. are (under some patent laws) more limiting, as they mean "having all and only, or virtually only, the following elements..."^{citation needed}

• A set of "limitations" that together describe the invention: "an X, a Y, and a Z connected to the X and the Y." The elements should be described as though they interact or cooperate to achieve the desired result.^{citation needed}

• Optionally, a purpose clause that further describes the overall operation of the invention, or the goal that the invention achieves ("wherein the Z simultaneously controls the X and Y," or "wherein the Z accomplishes purpose W by controlling X and Y," etc.)^{citation needed}

Interpretation or claim construction

The claims often comprise precise language. Certain words commonly used in claims have specific legal meanings determined by one or more court decisions. These meanings may be different from common usage. For instance, the word "comprise", when used in the claims of a United States patent, means "consisting at least of". By contrast, the word "consists" means "consisting only of", which may lead to a very different scope of protection.

Furthermore, in U.S. patent practice at least, inventors may "act as their own lexicographer" in a patent application. That means that an inventor may give a common word or phrase a meaning that is very specific and different from the normal definition of said word or phrase. Thus a claim must be interpreted in light of the definitions provided in the "specification" of a patent. The "specification" of a patent is a written description of how to make and use the invention (see also: sufficiency of disclosure).

Basic types and categories

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There are two basic types of claims:

• the independent claims, which stand on their own, and
• the dependent claims, which depend on a single claim or on several claims and generally express particular embodiments as fall-back positions. The expressions "in one embodiment", "in a preferred embodiment", "in a particular embodiment", "in an advantageous embodiment" or the like often appear in the description of patent applications and are used to introduce a particular implementation or method of carrying out the invention. These embodiments usually correspond to a dependent claim or could form the basis of a dependent claim. Each dependent claim is, by law, more narrow than the independent claim upon which it depends. Accordingly, it might appear that there would be little purpose to the dependent claim. In reality, however, there are at least three very important advantages to the patent applicant in submitting and obtaining a full string of dependent claims:

• Clarification of the independent claim language: Independent claims are typically written with very broad terms, to avoid permitting competitors to circumvent the claim by altering some aspect of the basic design. But when a broad term is used, it may raise a question as to the scope of the term itself. For example, does a "base" include a "set of legs"? A dependent claim, including the phrase, "wherein said base comprises a set of legs," if allowed by the patent examiner, clarifies that it does. In practice, dependent claims are often used to home in on the inventor's preferred embodiment of the invention (e.g., the actual product design that the inventor intends to use.) The independent claim broadly describes the invention; dependent claim #1 describes the invention in a narrower aspect that more specifically describes the preferred embodiment; dependent claim #2 is narrower still; etc.

• Possible invalidity of base claim: It is impossible to know, when beginning the application process and even at the time of patent issuance, if a patent claim is valid. This is because any publication dated a year or more before the application filing date and published anywhere on earth in any language can invalidate the claim (U.S. and Canada practice [but other countries are even stricter]). As it is impossible to gain an absolute and complete knowledge of every publication on earth, there is always some uncertainty. If the independent claim is determined to be invalid, however, a dependent claim may nevertheless survive, and may still be broad enough to bar competitors from valuable commercial territory.

• Claim differentiation: In United States patent law, under the doctrine of claim differentiation, each claim is presumed to cover a different aspect of the invention than in each other claim. This doctrine may be relied upon to help maintain broad claim scope in the case where a claim standing alone might be construed as having either a broad or a narrow interpretation. If a dependent claim is added that depends from this "parent" claim but is specifically drawn to the narrower interpretation, then the parent claim must necessarily be different - i.e., it must be the broader interpretation.^{citation needed} As construed in the courts, the doctrine of claim differentiation dictates that it would be "improper for the courts to read into an independent claim a limitation explicitly set forth in a dependent claim."Environmental Designs Lid. v. Union Oil Co. of California, 713 F.2d , 699 (1984).. This means that if an independent claim recites a chair with a plurality of legs, and a dependent claim depending from the independent recites a chair with 4 legs, the independent claim is not limited to the material recited in the dependent. The dependent claim protects chairs with 4 legs, and the independent claim provides protection for all other remaining chair-leg arrangements exclusive of the 4 leg arrangement.

Under the European Patent Convention, when a claim in one particular category (see below), e.g. a process claim, depends on a claim from a different category, e.g. a product claim, it is not considered to be a dependent claim but an independent claim. Under U.S. law, this is still counted as a dependent claim, regardless of the class change.^{citation needed}

The rules of claim drafting also permit "multiple dependent claims" that reference more than one other claim, e.g.: "3. The method of claims 1 or 2, further comprising..." The rules for this are quite specific: specific claims must be referenced ("the method of any of these other claims" is incorrect); the claims must be referenced in the alternative ("the method of claims 1 and 2" is incorrect); etc. While still acceptable, this claim style is seldom used in the U.S. because it is counted for filing fee purposes according to the number of claims that it references. Thus, if the claim depends from three former claims, it is counted for fee purposes as three dependent claims. In light of the "excess claim" fees currently imposed by the USPTO, this tactic can quickly become expensive. Instead, practitioners often recite the same alternative as a Markush grouping, which is always counted as one claim ("a method selected from one of the following groups: [method #1], or [method #2],..."). Multiple dependent claims are, however, very commonly used in other jurisdictions, including Canada and Europe ^{67citation needed}

Claims can also be classified in categories, i.e. in terms of what they claim. A claim can refer to

• a physical entity, i.e. a product (or material) or an apparatus (or device, system, article, ...). The claim is then called respectively "product claim" or "apparatus claim"; or
• an activity, i.e. a process (or method) or a use. The claim is then called respectively "process claim" (or method claim) or "use claim".

Special types of claims

Beauregard claim

In United States patent law, a Beauregard claim is a claim to an article of manufacture embodied as a computer-readable medium and instructions, named after decision In re Beauregard.⁸ Beauregard claims cover a computer-readable medium such as a storage device, such as a floppy disk or CD, or even a communication media, containing a set of instructions that causes a computer to perform a process. In the past claims to pure instructions were generally considered not patentable because they were viewed as "printed matter," that is, like a set of instructions written down on paper. However, in In re Beauregard the Federal Circuit upheld a computer program as patentable subject matter because it was claimed in terms of an article of manufacture as contained on a floppy disk. Consequently, such computer-readable media claims are commonly referred to as Beauregard claims.

When first used in the mid-1990s, Beauregard claims held an uncertain status, as contemporary cases (In re Lowry (1994)) implied that computer-readable media that contained merely "non-functional" data was unpatentable under the "printed matter" doctrine (which ruled unpatentable any "invention" that primarily comprised printed words on a page.) The case from which this claim style derives its name, In re Beauregard (1995), involved a dispute between a patent applicant who claimed an invention in this fashion, and a patent examiner who rejected it under this rationale. The appellate court (the United States Court of Appeals for the Federal Circuit) accepted the applicant's appeal - but chose to remand for review (rather than affirmatively ruling on it) when the Commissioner of Patents essentially conceded and abandoned the examiner's position. Thus, the courts have not expressly ruled on the acceptability of the Beauregard claim style, but its legal status is almost certainly accepted.^{citation needed}

However, although time has rendered the issue essentially moot with regard to conventional media, such claims were originally and can still be more widely applied.^{citation needed} The particular inventions to which Beauregard-style claims were originally directed - inventions involving computer-readable media - are no longer as interesting, because software deployment is rapidly shifting from computer-readable media (CD-ROMs, DVD-ROMs, etc.) to electronic distribution (internet delivery). Thus, Beauregard-style claims are less commonly drafted and prosecuted, although electronic distribution was practiced even during the time when Beauregard case was decided and clever patent drafters tailored the "computer readable medium" to encompass more than just floppy disks or other "insertable" media.^{citation needed}

Claims of this type have been allowed by the European Patent Office. ⁹

The UK Patent Office began to allow them following the EPO practice but then began to refuse them. The UK High Court overuled this practice by decision ¹⁰ so that now they are allowable in the UK as well.

Business method claim

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A business method claim is a claim that describes a business-related technique, such as a particular way of advertising a product or a particular way of contacting customers. The prototypical business method arises from State Street Bank v. Signature Financial Group, which involved a method of tracking individual shares in a complex pooled-stock portfolio, which was a complex accounting problem. The primary independent claim from the patent in this case (US PAT No. 5,193,056 ), which illustrates the general style of the business method patent claim, reads thus:

"A data processing system for managing a financial services configuration of a portfolio established as a partnership, each partner being one of a plurality of funds, comprising:

(a) computer processor means for processing data;

(b) storage means for storing data on a storage medium;

(c) first means for initializing the storage medium;

(d) second means for processing data regarding assets in the portfolio and each of the funds from a previous day and data regarding increases or decreases in each of the funds, assets and for allocating the percentage share that each fund holds in the portfolio;..."

...etc. (Though directed toward a "data processing system," dependent claim 4 in this same patent specifically re-characterize the invention as a "method," and the elements are recited as gerunds - i.e., as actions or steps.)^{citation needed}

Business method patents are doubly controversial: first because many critics¹¹ wish to differentiate patentable "technology" methods from unpatentable "business" methods; second, because many business methods are implemented as software, and many critics seek to exclude the patent system from the realm of software.^{citation needed} Both issues remain contentious intellectual property issues both within and outside the United States. See also business method patent.

Jepson claim

In United States patent law, a Jepson claim is a method or product claim where one or more limitations are specifically identified as a point of novelty, distinguishable over at least the contents of the preamble. They may read for instance "A system for storing information having (...) wherein the improvement comprises:". This claim’s name is based on a case, Ex parte Jepson, which was ruled on in 1917.

In a crowded art, a Jepson claim can be useful in calling the Examiner's attention to a point of novelty of an invention without requiring the Applicant to present arguments and possibly amendments to communicate the point of novelty to the Examiner. Such arguments and amendments can be damaging in future litigation, for example as outlined in the Festo decision.

On the other hand, the claim style plainly and broadly admits that that subject matter described in the preamble is prior art, thereby facilitating the examiner's (or an accused infringer's) arguments that the improvement is obvious in light of the admitted prior art, as per 35 U.S.C. § 103(a). Prosecutors and applicants are hesitant to admit anything as prior art for this reason, and so this claim style is seldom used in modern practice.

Markush claim

An example of a theoretical Markush structure.

Mainly used in chemistry, a Markush claim or structure is a claim with multiple "functionally equivalent" chemical entities allowed in one or more parts of the compound. According to "Patent Law for the Nonlawyer" (Burton A. Amernick; 2nd edition, 1991),

"In claims that recite... components of compositions, it is sometimes important to claim, as alternatives, a group of constituents that are considered equivalent for the purposes of the invention.... It has been permissible to claim such an artificial group, referred to as a 'Markush Group,' ever since the inventor in the first case... won the right to do so."

If a compound being patented includes several Markush groups, the number of possible compounds it covers could be vast. No patent databases generate all possible permutations and index them separately. Patent searchers have the problem, when searching for specific chemicals in patents, of trying to find all patents with Markush structures that would include their chemicals, even though these patents' indexing would not include the suitable specific compounds. This is where databases that permit searching of chemical substructures are indispensable.

Markush claims were named after Eugene Markush, the first inventor to use them successfully in a U.S. patent, in the 1920s. See: Ex parte Markush.¹²

According to the USPTO, the proper format for a Markush-type claim is : "selected from the group consisting of A, B and C." ¹³

In August 2007, the USPTO proposed a number of changes to the use of Markush-type claims.¹⁴

Means-plus-function claim

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A means-plus-function claim is a claim including a technical feature expressed in functional terms of the type "means for converting a digital electric signal into an analog electric signal". A variant known as a "step-plus-function" claim style may be used to describe the steps of a method invention ("step for converting... step for storing...")

Means-plus-function claims are governed by the various statutes and laws of the country or countries in which a patent application is filed.

United States

In the U.S., Means-plus-function claims are governed by various federal statutes, such as, 35 U.S.C. 112, paragraph 6, which reads: "An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof." This comparatively simple statement has proved to be a surprisingly difficult task during patent claim construction for applications in the US.

First, most claim styles are intended to be a succinct summary of the invention that stands alone and is interpreted largely on their own merits. By contrast, this claim style tacitly imports and relies upon the entire specification for interpretation, which is implausible (and also the reason for disallowing "omnibus" patent claims - see below.)

Second, the courts and notably the U.S. patent office have been somewhat inconsistent in specifying rules for when the "means-plus-function" interpretation is triggered. A claim reciting "means for [a specific function]" probably triggers the rule. Variations like "means of," "means by," or even "component for [a specific function]," etc. have been tried by these same tribunals, with inconsistent results.^{citation needed}

Third, U.S. courts and the U.S. patent office have rapidly proposed, modified, and deprecated several tests for determining the scope of "equivalents" of a means-plus-function element. This problem is exacerbated by the use of the term "equivalents," which is apparently similar to but not identical to the use of the same term in the "doctrine of equivalents" test of patent infringement.^{citation needed}

Many chapters and volumes have been written on the topic of interpreting the scope and requirements of the means- and step-plus-function claim style ¹⁵¹⁶. Despite the complexity of this area of law, which includes many ambiguous and logically contradictory opinions and tests, many practitioners and patent applicants still use this claim style in an independent claim if the specification supports such means-plus-function language¹⁵¹⁶.

Omnibus claim

A so-called omnibus claim is a claim including a reference to the description or the drawings without stating explicitly any technical features of the product or process claimed. For instance, they may read as "Apparatus as described in the description" or "An x as shown in Figure y".

European Patent Organisation

Omnibus claims are allowed under the EPC, but only "when they are absolutely necessary".¹⁷¹⁸¹⁹ Other patent offices, such as the United Kingdom Patent Office, are more receptive to this claim style. ^{20citation needed}

United States

Under U.S. patent law, omnibus claims are categorically disallowed in utility patents, and examiners will reject them as failing to "particularly point out and distinctly claim the subject matter which the applicant regards as his invention" as required by 35 USC 112 paragraph 2. By contrast, design patents and plant patents are required to have one claim, and in omnibus form ("the ornamental design as shown in Figure 1.")

Product-by-process claim

A product-by-process claim is a product claim where the product is defined by its process of manufacture, especially in the chemical and pharmaceutical industries. They may read for instance "Product obtained by the process of claim X," "Product made by the steps of . . .," and the like.

According to the European practice, they should be interpreted as meaning "Product obtainable by the process of claim...". They are only allowable if the product is patentable as such, and if the product cannot be defined in a sufficient manner on its own, i.e. with reference to its composition, structure or other testable parameters, and thus without any reference to the process.

The protection conferred by product-by-process claims should not be confused with the protection conferred to products by pure process claims, when the products are directly obtained by the claimed process of manufacture.²¹

In the U.S., caselaw suggests that product-by-process claims can be used even for products that can be sufficiently described with structure elements.

Reach-through claim

A reach-through claim is one that attempts to cover the basic research of an invention or discovery.²² It is an "attempt to capture the value of a discovery before it may be a full invention." ²³ Specifically, a reach-through claim is one in which "claims for products or uses for products when experimental data is provided for screening methods or tools for the identification of such products." ²⁴

A reach through claim can be thought of as an exception to the general rule about claims. ²⁵

An example of a denied claim was when the United States Federal Circuit refused to recognize a reach-through claim for Celebrex. ²⁶

Signal claim

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A "signal" claim is a claim for an electronic signal that can, for example, embodies information that can be used to accomplish a desired result or serve some other useful objective. One claim of this style might read: "An electromagnetic signal carrying computer-readable instructions for performing a novel method... " In accordance with such an example, patent coverage might be obtained for the transmission of software via digital signals, e.g., by the internet.^{citation needed}

The patent eligibility of this claim style is hotly contested. Opponents^who? cite 35 USC 101, which authorizes the issuance of patents only for "processes, machines, manufactures, and compositions of matter," and characterize "signals" as falling outside all of these "statutory classes." Opponents^who? also cite the long-standing principle that "abstract concepts," such as mathematical formulae and laws of nature, are not "inventions" as defined by U.S. patent law, and neither can be an abstract arrangement of data embedded on an electromagnetic carrier wave - which is essentially nothing more than a form of energy.

Proponents^who? of this claim style characterize the "signal" as an "article of manufacture," albeit one manufactured by a digital transmitter rather than by a foundry. Proponents^who? also object to the characterization of "signal" as abstract "energy," and often reference the relativistic fungibility of matter and energy. Accordingly, such proponents^who? argue, objections to signal claims as "ephemeral and transitory" are contrary to the teachings of modern physics.

The law on this issue is similarly split. In its Interim Guidelines for Examination of Patent Applications for Patent Subject Matter Eligibility, the U.S. Patent & Trademark Office instructs its examiners to reject categorically any patent claim that "recites nothing but the physical characteristics of a form of energy," and dismisses such claimed concepts as "nonstatutory natural phenomena." However, the Board of Patent Appeals and Interferences (an administrative law board within the same patent office) has previously reversed an objection that recited this same logic and categorically affirmed the patent eligibility of signal claims (Ex parte Rice.)

In the United States, transitory signal claims are no longer statutory subject matter under In re Nuijten. ²⁷ A petition for Rehearing En Banc and Certiorari to the Supreme Court were both denied.

Swiss-type claim

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A Swiss-type claim or "Swiss type of use claim" is a claim intended to cover the second or subsequent medical use (or indication) of a known substance or composition.

Consider a chemical compound which is known generally, and also is known to have a medical use (e.g. treating headaches). If it is then found to have a second medical use (such as restoring hair loss), the discoverer of this property will want to protect this new use by obtaining a patent for this new use.

However, the substance itself is known and cannot be patented. It lacks novelty under Article 54 EPC. Nor can the general concept of a medical formulation including this compound. This is known from the first medical use, and thus also lacks novelty under Article 54 EPC. Only the method of treatment is new. However methods for treatment of the human body by therapy are not regarded as inventions which are susceptible of industrial application under European law (e.g. Article 52(4) EPC^{dated info}) and are not patentable. Nor are methods of medical treatment patentable in certain other jurisdictions, including the Philippines and Canada (see MOPOP section 12.04.02)²⁸.

The Enlarged Board of Appeal of the European Patent Office solved this by allowing claims to protect the "use of substance X in the manufacture of a medicament for the treatment of condition Y".²⁹ This fulfilled the letter of the law (it claimed the manufacture, not the medical treatment), and satisfied the pharmaceutical industry also.

Because such claims had first been allowed in Switzerland they became known as "Swiss-type claims".

References

Further reading

• The construction of product-by-process claims, 11th European Patent Judges' Symposium, Copenhagen, Official Journal of the EPO 2003, Special Edition, No. 2, p. 20-75 (pdf)

See also

• Catnic Components Ltd. v. Hill & Smith Ltd. (1982)
• Claims under the European Patent Convention
• Clearance search and opinion
• Disclaimer
• Doctrine of equivalents
• Probatio diabolica, in relation to product-by-process claims
• Valid claim

External links

• European Patent Convention
  • Article 69 EPC defining the extent of protection
  • EPC Protocol on the Interpretation of Article 69 EPC
  • Article 84 EPC defining the role of claims
  • Rule 43 EPC (previously Rule 29 EPC 1973) expressing the legal requirements regarding the form and content of the claims
• US patent law (Title 35 of the US Code)
  • 35 USC § 101 patentable subject matter
  • 35 USC § 112 specification and claims
• Studies on patent claims
  • When small is beautiful: measuring the evolution and consequences of the voluminosity of patent applications at the EPO This paper addresses issues in measuring the voluminosity of patent applications (number of claims and pages) and highlights patterns in its evolution.