The claims in the Claim Set are the primary focus of the patent application because the claims define the scope of patent protection afforded by the patent. There must be at least one independent claim in a nonprovisional patent application. The claims should focus on the point of novelty and use terms and phrases to describe the invention’s structure and/or method steps. The preparation and examination of the patent application begin and end with the claims of the Claim Set, which defines the scope (i.e., metes and bounds) of protection afforded by the patent. The claims should therefore be broad enough to encompass competitive alternatives of the potential invention and to therefore hinder third parties from producing a similar product with which they could compete for the same customers. Narrow claims may pass through examination easier, but are generally less useful because a competitor would be able to easily design around the narrow claim and compete in the marketplace. They are useful in limited circumstances.
The Claims section is the most difficult to prepare properly. It should therefore be prepared by a competent patent attorney, not a layperson. A single word in a patent claim can unduly limit the scope of the protection afforded by the patent, narrowing its protection and enabling competitors to design around the invention and avoid infringement liability. What follows is not a tutorial on how to write a proper claim, only an introduction to claims of the Claims section so that a new inventor or layperson can rudimentarily understand how the claims work.30
The anatomy of a claim
The “Claim Set” is normally included at the back of the patent application or patent and starts with the phrase “what is claimed is,” “I claim,” or “we claim.” Claims come in two varieties: an apparatus claim or a method claim. An apparatus claim is directed to a product. The method claim is a series of steps directed to the use of the product or some other steps in relation to the invention such as how the product is manufactured. The basic filing fee for a utility, nonprovisional application allows the inventor to present three independent claims (independent versus dependent claims, explained below), and a total of twenty claims (independent and dependent) at no additional cost. Each additional claim incurs a cost. Since cost is an issue for most inventors, the best approach is to present only high-value claims within the “3—20 rule” above.31
An individual claim consists of three parts: preamble, transitional phrase, and claim limitations. Below is an example of a claim for the mechanical pencil invention:
A mechanical pencil for handwriting on a piece of paper, the pencil comprising:
a tubular body having a bottom and top ends;
a mechanical clicker system disposed on the tubular body; and
a removable eraser to access a depository for lead rods within the tubular body.
The preamble is first and usually starts with a phrase such as “an apparatus for [fill in the purpose of the apparatus].” In the example above it states: “A mechanical pencil for handwriting on a piece of paper.” This is another way to say the same thing. The second part, the transitional phrase, is indicated by phrases such as “comprising,” “consisting of” or “consisting essentially of.” The example above states: “the pencil comprising.” Each transitional phrase has a significantly different meaning and affects the scope of the patent differently. For the layperson, the most common transitional phrase is “comprising” since this is the broadest form of transitional phrase. Think of “comprising” as meaning “including, but not limited to.” The third part is the body of the claim, and it lists the elements of the invention and the claim’s limitations (this will be explained in more detail below).
Claims are either independent or dependent. A claim is independent if it does not depend on another claim, while claims that do depend on previous claims are referred to as dependent claims. The claims are sequentially numbered in this section. Claim 1 is normally an independent claim and does not refer to a different claim. Claim 2 is normally a dependent claim referring to Claim 1 and incorporates within itself all the limitations recited in Claim 1.
The above example would be considered an independent claim, which I will refer to as “Claim 1”.
A claim dependent on Claim 1, labeled “Claim 2,” might read:
- The pencil of Claim 1 wherein the mechanical clicker system is positioned on the body adjacent to an index finger to allow the user to conveniently depress a button of the mechanical clicker system while using the pencil to write on the piece of paper.
By definition, Claim 1 is broader than Claim 2. Claim 2 is narrower than Claim 1 as it requires that the mechanical clicker system be located near the index finger position on the tubular body. A patent’s broadest scope of protection is determined by the independent, not dependent, claims because it has fewer requirements that must be met in order to find that a product or method infringes. How to determine whether infringement exists is discussed below.
Since dependent claims do not determine the broadest scope of protection, one might ask why they are necessary. There are a variety of reasons for including dependent claims in the patent application. During the examination stage, the examiner uses prior art references to contend that the invention, as defined by the independent claims, is not novel. The examiner could assert that the claim is broad enough to encompass, or constitute an obvious variant of existing technology (i.e., the prior art anticipates the invention and therefore the invention is not novel). The dependent claims mitigate this potential issue by narrowing the broader, independent claims. The examiner may allow some of the narrower, dependent claims but not the broader, independent claims. In this case, the applicant only needs to amend the independent claims to incorporate the limitations of the allowed dependent claims to secure a patent.
In another situation, should litigation occur in which an accused infringer attempts to avoid patent infringement liability by attacking the novelty of independent claims,32 and if independent claims are determined to be invalid, dependent claims may still be valid. If they are still valid, the dependent claims are used to determine whether the accused infringer is liable. As such, the dependent claims also help to increase the likelihood that a claim is still valid, albeit dependent, should an independent claim be invalidated during litigation.
The purpose of a claim: to determine the scope of patent protection
The claims of an issued patent, ideally, describe the invention’s point of novelty and prohibit competitors from copying an invention’s point of novelty lest they be liable for patent infringement. The claims should be sufficiently broad so that the competitor has to make one or more significant changes to its product so that the product would be placed at a disadvantage when competing in the market. If the claims focus on peripheral aspects of the product instead of the point of novelty, competitors may not have a significant barrier to entry and could easily design around the claim by not including that peripheral aspect in their product. It is therefore important to focus on the point of novelty in the Claims section rather than unrelated, minor improvements at least in the independent claims.
The scope of a claim is determined by limitations recited within the body of the claim. For example, a claim to a wooden pencil may recite:
An apparatus for making marks on a sheet of paper, the apparatus comprising (i.e., is made up of):
an external protective member having a length longer than a width of the external protective member;
a lead material disposed within the external protective member and held in place by the external protective member; and
an eraser attached to an upper portion of the external protective.
The wooden pencil claim includes three elements: (A) external protective member, (B) lead material, and (C) eraser. A competitor must incorporate all three elements to infringe on the wooden pencil claim. Table 5 below illustrates how to determine if a device literally infringes on the pencil claim above. The first column refers to the three elements listed above. Product numbers 1-5 refer to hypothetical versions of the product that a competitor might create. These hypothetical products may incorporate some of the pencil’s elements, or a new element, “D.”
If a competitor incorporates elements A and B only (i.e., product 2), he or she is not infringing on the wooden pencil claim because the competitor did not incorporate element C and therefore did not include all three of the pencil’s defining elements. The same is true for Products 3 and 4. Product 1, however, is literally infringing on the pencil claim because it incorporates all three of the pencil’s claim elements. If a competitor incorporates an element “D” in addition to all three elements A, B, and C (product 5), the competitor still infringes on the wooden pencil claim. The addition of element D does not negate that the infringer incorporated elements A, B, and C into its pencil. Product 5 therefore literally infringes on the pencil claim.
In the above claim, each paragraph contains one element. This is a simplified approach to thinking about claim scope and infringement. However, each word of a claim may be a limitation that must be incorporated into the competitive product for it to be liable for infringement. Any change to the competitive product that does not incorporate all the elements as described by the claim may enable the competitor to avoid infringement. For example, in our wooden pencil example, the eraser is described as being at the top of the external protective member. If a competitor made a pencil without an eraser, that product would not literally infringe on the wooden pencil claim.
A product is analyzed to see if it incorporates all the limitations of a patented invention’s claims to determine whether it literally infringes on a claim of the patent. If a court determines that the competitor’s product does incorporate all the elements of the claims, the product literally infringes on the claims of the patented invention.
Even if a product does not literally infringe a claim, the defendant may still be liable for infringement under the Doctrine of Equivalents which broadens the scope of the claims beyond its literal scope.
Generating the Claim Set
Most inventors believe that securing the broadest patent protection from the start is the best strategy. Broad patent protection may be possible but is often expensive. Broader claims are more likely to be rejected and the rejection maintained during the examination process for being anticipated by the prior art and/or considered obvious. An inventor could argue with the examiner and fight for the broadest claim scope desired and then slowly narrow the claim, but that strategy would expend considerable resources. A strategy that I have implemented for many solo inventors and startups is to initially seek a medium-scope claim, one which provides a significant barrier to entry for competitors but is hopefully easier to obtain. I do not recommend a strategy that initially seeks to secure a patent with a narrow scope without a specific reason. For some inventors, mere ownership of a patent, even with a narrow scope, may be valuable. However, inventors should understand the severe limitations provided by such a patent and such a strategy should not be implemented unless the inventor has a clear understanding of its limitations.
The basic process of generating a Claim Set involves thinking about all the potential entities that might want to infringe on the claimed invention. This may include all the entities along the chain of distribution including, but not limited to, the manufacturer, distributor, retailer, and end user. Inventors should consider including claims that address each of these in a patent application when submitting the patent application for examination. For example, a claim regarding the method for making a mechanical pencil may be ideal to get a manufacturer to be liable for patent infringement, but it would not permit the patent owner to sue an end user who only uses, but does not manufacture, the mechanical pencil. Likewise, a claim directed to the method for using the mechanical pencil may be ideal to get an end user to be liable for patent infringement, but not permit the patent owner to sue a manufacturer. The method for making the mechanical pencil is likely more valuable than its method of use because the inventor would presumably want to stop the manufacturer rather than the end user (since it may not be economically feasible to sue all individual end users).33
The default rule for listing claims in the patent application is to present the broadest claim as Claim 1.34 Each successive dependent claim narrows the scope of protection of Claim 1. Each successive independent claim should address a different entity (such as the manufacturer or end-user) or focus on a different aspect of the invention or point of novelty in an attempt to provide broad coverage collectively with all of the independent claims. For example, if independent Claim 1 is directed to the apparatus, the second independent claim could address the method of manufacture. The inclusion of a claim addressing the method of manufacture can preclude another manufacturer from making and selling the product against the will of the patent owner. The third independent claim could focus on a different entity along the chain of distribution.35
An examiner may allow some, but not all, claims. If the allowable claims have a medium breadth, canceling the rejected claims and letting the allowable claims mature into a patent may be the best course of action. The broader, rejected claims can be sought in a subsequent application that claims priority back to the first, parent, patent application.36
In particular, the scope of patent protection can be broadened by filing a “continuation patent application.” The continuation patent application can be filed, and claim priority back to the first, parent application, any time before the parent patent issues or is abandoned. Clients sometimes ask whether the filing of the continuation patent application will delay the patent grant based on the parent application. The answer is no. If the parent application has allowed claims, and the inventor has decided to pay the issue fee so that a patent is granted on the allowed claims, the filing of the continuation patent application does not affect the timing of the grant of the parent patent. The continuation patent application is a refiling of the parent application with a Claim Set that can mimic the allowed claims but be slightly broader so as to improve the scope of patent protection for the invention. For more information about filing a continuation patent, see FAQ #22-#29 in Section 3.
30. This section discusses “literal infringement” only. It does not cover infringement under the Doctrine of Equivalents (DOE). To determine the proper scope of patent protection under an issued patent, including infringement under the DOE, an inventor will need to retain competent patent counsel, as DOE and claim interpretation is complex and ever-changing and therefore difficult to do without keeping up with the current state of the law.
31. By high value, I am referring to claims that can be used to stop entities from engaging in infringing actions. For example, a claim in which the end user is infringing on the patent may be generally less valuable than one in which a manufacturer would be infringing because suing all the end users would be unfeasible. It would be much simpler to enjoin the manufacturer to stop the infringing actions to prevent the end users’ access to the infringing
32. One distinction between the role of the accused infringer and the examiner is that an accused infringer is an adversary to the patent owner whereas, the interaction between the examiner and the inventor is not an adversarial relationship. The examiner and inventor should cooperatively investigate the invention so that the inventor receives a patent only for inventions to which he or she is entitled under a U.S. patent
33. This does not necessarily mean that a claim to a method is useless. The end user’s infringement liability can be attached to the manufacturer. A competitor can infringe on a product directly or indirectly. The manufacturer can infringe directly on the method of manufacturing claim but not the method of use claim. The manufacturer would be liable for the method of use claim according to the theory of indirect patent infringement. In this case, the manufacturer contributes to, or induces, the end user’s direct infringement on the method of use claim. Therefore, the method of use claim provides valuable protection under a theory of indirect infringement. However, the method of manufacture claim would be more valuable for imposing patent infringement liability directly on the
34. See Appendix B for an example of how claims are numbered within the Claims
35. Sometimes it is difficult to secure a patent on the method of manufacturing or even on the apparatus itself. In this case, securing a patent on the method of using the product from the perspective of the end user would enable a patent owner to sue, not the end-user on the grounds of direct infringement, but the distributor on the grounds of indirect infringement. Direct infringement happens when an entity is personally engaging in the prohibited acts of making, using, selling, or offering to sell the patented product for use in the U.S., or importing the patented product into the U.S. Indirect infringement occurs when an entity is not directly infringing on the claims of the patent, but rather is contributing to someone else’s direct infringement. Since the distributor is not directly infringing on the patent claim, the distributor may be sued according to the “theory of indirect infringement” for contributing to, or inducing, the end user’s infringement. Claims that target a direct infringer are preferable because indirect infringement liability is more difficult to prove. It must be shown that the targeted entity is contributing to the direct infringement of
36. The first, parent patent is often the most valuable in an inventor’s patent portfolio because it allows the inventor to mark the invention as patented with the patent number. The product is no longer merely patent pending but officially patented. This is called “patent marking” and it allows the inventor to place the public on notice of its patent. Patent marking places competitors that can be held liable for damages for patent infringement beginning from either the time of infringement or patent marking, whichever occurs later. Patent marking acts as a constructive notice to competitors of the patent. Actual notice of the patent occurs when a patent owner sends a cease-and-desist letter to the accused infringer identifying the patent and infringing product. The first, parent patent also incurs additional costs to competitors because they must hire their own patent attorneys to determine the scope of patent protection afforded under the first patent.