3.1 Independent Claims
Independent claims define the widest scope of protection available within a patent. Although certain independent claims may be broader than others, any independent claim is necessarily broader than all claims that depend on it. An independent claim is self-contained and does not rely on limitations from another claim in order to be complete. Every claim set begins with an independent claim.
Professional Tip:
When preparing a claim set, carefully balance the intended scope of protection, the related costs, and the legal requirements imposed by the relevant patent law.
A patent application may include several independent claims. This may be required where a single invention incorporates multiple distinct aspects that cannot be effectively protected by one broad claim alone. In such situations, it is generally recommended to draft multiple independent claims, each designed to protect a specific aspect of the invention.
Claim breadth should not be confused with claim type. A patent drafter may decide to include several independent apparatus claims, each directed to a different component or feature of the apparatus. Moreover, even when claims relate to the same aspect of the invention, the drafter may prepare multiple claims of different scope in order to capture a wider range of potential infringement activities. The objective is not merely to prevent competitors from manufacturing products that embody the inventive concept, but also to ensure that the claim has practical enforcement value beyond targeting end-users (customers), who are less likely to constitute the principal infringers.
The legal doctrine of unity of invention generally requires that multiple independent claims within a single patent relate to one invention or to a group of inventions that share a single general inventive concept. Although the presence of multiple inventions in a single application is not strictly prohibited, patent offices will only grant a patent if all claimed subject matter essentially relates to a single core inventive concept.
Professional Tip:
Aim to obtain an appropriate number of claims for your client’s invention. With experience, you will learn to identify the point at which the costs associated with additional claims (such as excess claim fees and annuity fees) begin to outweigh the benefits.
At the United States Patent and Trademark Office (USPTO), an additional fee is required for each independent claim beyond the first three. In certain jurisdictions, such as the European Patent Office (EPO), the number of independent claims is limited, usually permitting only one per category (for example, one independent product claim and one independent process claim per application). This approach promotes administrative efficiency by discouraging the excessive use of independent claims. The EPO does provide exceptions to this rule, However:
-
Examples of a plurality of interrelated products …
plug and socket
transmitter- receiver
intermediate(s) and final chemical product
gene- gene construct- host- protein- medicament
[ … ] -
Examples of a plurality of different inventive uses of a product or apparatus …
claims directed to further medical uses when a first medical use is known …
[ … ] -
Examples of alternative solutions to a particular problem …
a group of chemical compounds
two or more processes for the manufacture of such compounds
Varying the scope of claims can also function as a safeguard against challenges asserting patent invalidity based on prior art particularly in disputes that arise many years after a patent has been granted. It is relatively common for alleged infringers to uncover significant prior art only during litigation. By drafting claims with different levels of breadth, patent drafters can better protect against prior art that may not have been known to the inventor, the patent drafter, or even the patent examiner during the examination process.
An independent claim must generally define the essential features required to characterize the invention. Although the specific requirements regarding these features may differ between patent offices, they do not always need to be explicitly stated if they are inherently implied by the generic terminology used (for example, a claim directed to a bicycle typically does not need to explicitly mention wheels). However, when patentability depends on achieving a particular technical effect, the claims should include all technical features necessary to achieve that effect. Therefore, claims must be clear and focused on the central inventive concept.
If a claim relates to a process for producing a product X, it should be drafted in such a way that carrying out the process in a manner that would be reasonable for a person skilled in the art will inevitably result in product X. If this condition is not satisfied, the claim may contain internal inconsistency and lack clarity. For product claims, where the product itself is already known and the inventive contribution lies in particular modifications, it is generally sufficient for the claim to clearly identify the known product while specifying the modifications and describing their nature. Comparable considerations apply to apparatus claims.
Dependent Claims: Backup for Broad Claims
Patent drafters frequently prepare a combination of broad and narrow claims to comprehensively cover the scope of an invention. In practice, this usually involves drafting the broadest independent claim first and then adding a sequence of dependent claims that define progressively narrower embodiments.
Dependent claims function as a “fallback” position for the patent drafter. Even when a prior art search has been performed, it cannot guarantee that all relevant prior art has been identified; there is always the possibility that a patent examiner will uncover prior art that challenges the novelty or inventive step of the claimed invention. If the examiner identifies prior art that renders the broad independent claim unpatentable but does not affect the narrower dependent claims, protection may still be granted based on those dependent claims. Although narrower dependent claims are generally considered less “strong” than broad independent claims, they may still provide sufficient protection to give the applicant a meaningful competitive advantage in the marketplace.
Format and Structure of Dependent Claims
A dependent claim is a claim that “depends from” another claim, which may be either an independent claim or another dependent claim. This relationship is indicated by expressly referencing the claim from which it depends. For instance, the phrase “2. The apparatus of Claim 1, further comprising…” signals that Claim 2 depends on Claim 1.
The structure of a dependent claim promotes conciseness by removing the need to repeat the entire wording of the referenced claim. By referring to another claim, the dependent claim incorporates all features of the parent claim together with any additional limitations recited in the dependent claim itself. As a result, dependent claims are typically much shorter than independent claims. It is therefore a common misunderstanding among those new to patent drafting that dependent claims have broader scope than independent claims; in reality, the opposite is the case.
Example
An independent claim (Claim 1) reads:
- An apparatus, comprising:
a pencil; and
an eraser attached to the pencil.
A dependent Claim 2 reads:
2. The apparatus of Claim 1, further comprising:
a light attached to the pencil.
A dependent Claim 3 reads:
3. The apparatus of Claim 2, further comprising:
a pencil lead release button attached to the pencil.
A further dependent Claim 4 reads:
4. The apparatus of Claim 2,
wherein the light is an LED light.
The entirety of the dependent Claim 2 includes all the text affirmatively recited in Claim 2 plus all the text of Claim 1. Thus Claim 2 actually reads:
2. An apparatus, comprising:
a pencil;
an eraser attached to the pencil; and
a light attached to the pencil.
Similarly, Claim 3, which depends from Claim 2, which itself refers to Claim 1, actually has the same scope as would the following independent claim:
3. An apparatus, comprising:
a pencil;
an eraser attached to the pencil;
a light attached to the pencil; and
a pencil lead release button attached to the pencil.
As illustrated previously, dependent claims that refer to the same independent claim frequently share an identical preamble. Although this is not always mandatory, independent claims commonly begin with the indefinite article “A” or “An,” whereas dependent claims generally begin with the definite article “The.”
Dependent claims are always narrower in scope than the claims from which they depend. For instance, if a competitor manufactures pencils that do not include an integrated light, those pencils would not infringe a dependent claim (e.g., Claim 2) that requires such a feature, even though they might still infringe a broader independent claim (e.g., Claim 1) that does not contain this limitation.
Following the preamble, a term or phrase typically indicates the dependency on another claim. This phrase is interpreted as incorporating all limitations specified in the parent claim. In our example, the wording “The apparatus of Claim 1… .” is used. Other commonly used expressions include “The apparatus according to Claim 1” and “The apparatus as in Claim 1.” Furthermore, phrases such as “as claimed in,” “as per,” “as set forth in,” and “as recited in” may also be employed to indicate this dependency.
Immediately after referring to the parent claim, a dependent claim introduces at least one additional feature that is not present in the parent claim. This can generally be accomplished in one of three principal ways:
- Addition of a New Element: By adding a new element, E, usually expressed as “further comprising E.” For example, in a dependent claim, a light attached to a pencil would constitute a new element that is absent from the parent claim (e.g., Claim 1).n/
- Narrowing of an Existing Element: By selecting a specific element, E1, from a broader element, E, recited in the parent claim. This is commonly expressed as “wherein E is E1” or “in which E is E1.” For example, if the parent claim broadly refers to a “light,” a dependent claim might specify “wherein the light is an LED light” or further define the light, such as “wherein the light is detachable.”
- Combination of (i) and (ii):
A dependent claim may simultaneously introduce new elements while also further defining or restricting existing ones.
Dependent claims should be organized in a logical manner to make the relationships between the claims clear and easy to interpret. Importantly, every dependent claim must refer back to at least one earlier claim and may not refer forward to a later claim. Under no circumstances may a dependent claim broaden the scope of protection provided by the associated independent claim.
The hierarchical structure between independent and dependent claims can be effectively illustrated as a claim tree, in which each claim is represented by its number and connected by arrows or lines to the claim or claims on which it depends.
Figure 2
In circumstances where a patent examiner identifies prior art that invalidates an independent claim but does not affect a dependent claim, several strategic responses are available. Although the patent drafter and the client may choose to challenge the rejection of the parent claim, they might alternatively decide to proceed by canceling the rejected independent claim (together with any intervening dependent claims). Afterward, a new independent claim can be formulated by incorporating the limitations of the canceled independent claim together with those of the allowable dependent claim. The patent drafter may then amend the remaining claims in the application so that they depend from this newly created independent claim (which was previously a dependent claim).
Example
An application contains one independent claim (Claim 1) and 10 additional claims that ultimately depend from Claim 1.
The first three claims read:
- An apparatus, comprising:
- a pencil; and
- an eraser attached to the pencil.
- The apparatus of Claim 1, further comprising:
- a light attached to the pencil.
- The apparatus of Claim 2, further comprising:
- a pencil lead release button attached to the pencil.
The patent examiner has rejected Claim 1 but has indicated that Claim 2 is allowable and has objected to Claim 2 only because it depends on rejected Claim 1.
If the client agrees with the proposed course of action, the patent drafter may rewrite Claim 2 as a new independent Claim 1 by expressly including all limitations of Claim 1 (as illustrated earlier). Former Claim 2 will therefore be renumbered as Claim 1:
- An apparatus, comprising:
- a pencil;
- an eraser attached to the pencil; and
- a light attached to the pencil.
Claim 3 already depends from the former Claim 2, which is now Claim 1. Consequently, Claim 3 does not require substantive modification but only a formal amendment so that it now refers to “Claim 1,” and it will be renumbered as Claim 2:
- The apparatus of Claim 1, further comprising:
- a pencil lead release button attached to the pencil.
Once the patent drafter submits this amendment, the patent examiner will most likely allow the patent application, and the client will ultimately obtain a patent containing a total of 10 claims rather than.
Although amendment formats differ among jurisdictions, a request to amend Claim 2 in order to convert it into an independent claim might appear as follows:
- An apparatus, comprising:
- a pencil;
- an eraser attached to the pencil; and
- a light attached to the pencil.
The strikethrough indicates deleted text, while the underlining identifies newly inserted text.
Alternatively, the amendment may involve modifying the original Claim 1 by incorporating the limitations that previously appeared in the original Claim 2:
- An apparatus, comprising:
- a pencil;
- an eraser attached to the pencil; and
- a light attached to the pencil.
A dependent claim functions by introducing additional elements or limitations to the claim from which it depends; it is not permitted to remove any elements or limitations. In other words, a dependent claim may only narrow the scope of the referenced claim and can never expand it.
For example, the following would represent an improper dependent claim:
“4. The apparatus in Claim 2 wherein the light is not attached to the pencil.”
This claim is defective because it attempts to eliminate an element namely, the light that was introduced in the preceding claim.
Professional Tip:
If the independent claims are found allowable over the prior art by the patent examiner, the dependent claims will likewise be considered allowable by extension. In such circumstances, amendments to the dependent claims are generally unnecessary.
Dependent claims can also be used strategically to reinforce a broader interpretation of the independent claims. Consider a scenario where Claim 1 recites “a box,” and a dependent Claim 2 specifies “wherein the box is wooden.” The language in Claim 2 clarifies that Claim 1, by implication, encompasses boxes constructed from any material, including wood as well as other materials.
Although it might be argued that the phrase “a box” in Claim 1 could include boxes made from non‑wooden materials, an opposing party might assert that the patent specification does not adequately support such non‑wooden boxes. However, the presence of “wooden box” in Claim 2 strengthens the patentee’s position. It suggests that the patent examiner considered the enablement requirement and concluded that the specification sufficiently supports boxes made from both wooden and non‑wooden materials within the scope of Claim 1. This explicit reference therefore helps reinforce the breadth of the independent claim.
The Secretariat of WIPO assumes no liability or responsibility with regard to the transformation or translation of the original content. World Intellectual Property Organization (WIPO) (2023). WIPO Patent Drafting Manual, Second edition. Geneva: WIPO. DOI: 10.34667/tind.44657