How Is Patent Infringement Determined?

Owning a U.S. patent gives you important rights over your invention. However, facing patent infringement battles can cause innovators to struggle with costly, prolonged litigation that can drain resources and stall business growth. This guide outlines a step-by-step approach on how to prove patent infringement, including how our patent lawyers execute these steps to secure justice for our clients.

How to Prove Patent Infringement

The process of proving infringement begins with proving ownership and defending the patent’s validity, followed by collecting evidence through proper documentation of the product or process infringement. Next, determine the infringement’s scope using intrinsic and extrinsic evidence to perform a detailed claims construction analysis. Collectively, these identify whether it’s a direct or indirect infringement.

Patent infringement is when someone carries out an act that infringes on a patent owner’s legal intellectual property (IP) right without the permission of the patent owner. This article will provide the key elements in determining whether infringement has actually occurred. 

1. Establish Ownership of a Valid Patent

Under 35 U.S.C. § 282, an issued patent is presumed valid. However, it helps to show proof that you own a valid patent and the infringing use.

Prove Legal Ownership and Defend Patent Validity

Patent ownership is generally proven based on written documentation of ownership assigning the patent to you. This is often the official documentation provided by the United States Patent and Trademark Office (USPTO) when it approves the patent. However, this documentation could also be a contract assigning to you the ownership rights of a patent.

An issued patent is presumed valid as it shifts the burden to the defendant to prove invalidity. Even if a patent has been issued for an invention, the validity of that patent can still be called into question. Courts can decide that a patent is invalid for a number of different reasons, such as:

• Withheld information on a patent application;
• False information on a patent application;
• A claim within the patent is determined to be obvious;
• The description and/or the claims were indefinite

Identify the Infringer

A patent infringement action would name as a defendant every alleged patent infringer. It could be that multiple organizations were involved with building and selling the infringing invention in a collaborative process. Every organization needs to be named in your infringement complaint.

Don’t worry if you don’t know the names and identities of every infringing individual or entity before you bring your lawsuit. You will have the opportunity to amend your complaint several times in the patent litigation process to name additional parties as you learn more information.

Determine the Similarity to One or More Patent Claims

This element addresses the specific claims that make up the patent. To prove infringement, you must demonstrate infringement of a specific patent claim by the accused product.

Patents are made up of at least one, and often various “claims” that together make up the patented invention. The infringing product must infringe on at least one of these claims as listed in the patent approved by the Patent Office.

2. Gather Specific Evidence of the Accused Product or Process Infringement

Proving that a product or process infringes requires evidence that patent claim elements are present in the accused technology. To meet these standards, you’ll need to do extensive investigative and technical analysis. Our experienced patent lawyers can make sure that admissible evidence correctly maps to the claims.

Collect Evidence of the Act

You will need to identify a specific act of infringement carried out by the infringing party. As addressed above, infringement is the making, using, selling, or offering to sell a patented invention.

This is what will need to be proven. One or more distinct acts by the infringer must be established to meet this requirement. The best evidence for proving infringement will be the physical evidence of the competing invention.

The accused product can be compared side by side with the patented invention. With an indirect claim, you will ideally have some documentary evidence of directing or assisting in the infringement, perhaps in emails or letters.

Obtain Product Documentation

After a court has constructed the applicable claims in an infringement lawsuit, the factfinder must then determine whether or not the accused product is an infringing product based on the applicable claims. This is typically done in the context of a jury trial. 

Expert testimony is presented on both sides to discuss the competing inventions. This also presents arguments as to why the accused product infringes or does not infringe on the applicable patent.

Documentary evidence in the form of diagrams, charts, journals, emails, and the like, demonstrates similarities and differences between the accused product and the patented one. After the evidence is presented, the factfinder will determine whether or not the competing invention has infringed on the patented invention. 

3. Determine the Legal Meaning and Scope of the Patent Claims (Claim Construction)

The United States Court of Appeals for the Federal Circuit handles appeals related to specific areas of federal law, including patents. In the court system, they are one level below the Supreme Court and can set the standards that must be applied to patent law claims in federal district courts within every state.

It has established specific requirements for these hearings, or Markman hearings, and the type of evidence that can and should be reviewed at the hearing. Claim interpretation, known as claim construction, is a mandatory and often contentious legal process in patent litigation. The court defines the scope and meaning of a patent’s claims, primarily in light of the patent’s specification.

Review Intrinsic Evidence First

Intrinsic evidence helps the court give the specific patent claim the meaning it would have to a person of ordinary skill in the applicable field at the time the invention was established. The person of ordinary skill can be defined as a fictional, objective person who has the average knowledge, skill, and expertise in the specific technical or scientific field of the claimed invention.

Intrinsic evidence helps preserve a patent claim’s validity except where that would conflict with the claim’s language and corresponding specification. These elements make up the public record of a patent via patent searching within the Patent Office database. There are three types of intrinsic evidence used by the courts in evaluating construction:

• Patent’s claims: Patent claims define the scope and boundaries of the patented invention. Claims must distinguish themselves from the applicable and relevant prior art. 
• Patent’s specification: Some terms within a claim may have a different meaning than the term’s ordinary and customary meaning. Courts look to a patent’s specification to determine a term’s meaning within a claim as it is used within the context of the invention in its entirety.
• Patent’s prosecution history: This history can often show significant back-and-forth communications between the patent examiner and the patent applicant. This paper trail provides helpful information that sheds light on the proper interpretation of a claim’s scope.

Consult Extrinsic Evidence Only If Necessary

Extrinsic evidence is relevant information outside of the intrinsic evidence that assists in analyzing a patent claim. It’s often used if the meaning of a claim and its applicable limitations are not apparent from the intrinsic evidence. A court looks to extrinsic evidence to resolve any lack of clarity in a claim and its corresponding terms.

In some cases, intrinsic evidence considered as a whole doesn’t allow a court to fully interpret a term of art used in a patent claim. For this reason, extrinsic evidence may be used to shed light on that specific term. Extrinsic evidence includes evidence such as:

• Expert testimony
• Pertinent treatises
• Applicable journals
• Dictionary definitions

4. Compare the Construed Claims to the Evidence to Prove Infringement

Because a court conducts claims construction rather than a factfinder, the claims analysis can be done before trial at summary judgment if not earlier in the legal proceeding. A court must construct the patent claims before a factfinder can evaluate those construed claims against the allegedly infringing invention.

Perform a Claim Construction Analysis

The claims construction analysis for lawsuits is considered a legal issue as opposed to a factual issue. Courts apply a general legal framework when construing claims, which you can follow in your infringement analysis.

The construction of a patent’s claims is determined by a federal court, not by a factfinder. The International Trade Commission (ITC) can also complete the analysis on specialized and specifically applicable proceedings regarding the importation of allegedly infringing goods. 

• One key element in proving infringement is proving that a specific patent claim listed in a validly issued patent has been infringed on by the infringing product at issue. To infringe a claim, the infringer must meet each element in it.
• Claims construction determines the scope and meaning of a patent’s claims. Properly interpreting and defining the scope and meaning of a patent claim can determine whether a patent has been infringed. 
• Significant financial and time resources are often spent on the process and analysis. This is because patent infringement claims very often hinge on the interpretation of a patent claim’s scope.

Argue the Doctrine of Equivalents

The doctrine of equivalents is a legal doctrine that can come into play in lawsuits. It enables finding of patent infringement for a patented invention even if an infringing invention doesn’t fall within the literal scope of the infringed invention, yet is nevertheless equivalent to the infringed invention.

To use the doctrine of equivalents, the competing invention must perform substantially the same function as the infringed invention or in the same manner to achieve the same result. 

However, there are limitations to the legal doctrine of equivalents. This doctrine must be applied to the individual elements of a patent claim rather than to the patent as a whole.

5. Identify the Infringing Party and the Specific Act

There are types of patent infringement. This provides you with numerous ways to bring a legal claim to court.

Direct Infringement

According to 35 U.S.C. § 271 of the U.S. patent law, direct infringement occurs when a single entity’s product or service meets the limitations of at least one independent patent claim. The infringing party doesn’t need to know that your patent exists to be held liable. Prohibited uses include making, selling, or importing to sell an invention within the United States.

Indirect Infringement

Indirect infringement is found when an individual or entity causes or assists another individual or entity in infringing on patented property. This infringement must infringe on at least one material aspect of the patent claim.

Induced Infringement

Inducing infringement occurs when an individual or entity actively induces another person or entity to make prohibited use of someone else’s patent. For example, if an entity actively emails the ingredient list for a specific patented recipe to another entity, this would be induced infringement. 

Contributory Infringement

Contributory infringement occurs when a person or entity knowingly provides a product or component of a product or service that helps the recipient directly infringe on a patent. Also, the provided product or component must not have a substantial non-infringing use, which is a patent that isn’t unusual, far-fetched, illusory, occasional, or experimental.

How to Detect an Act of Infringement

Before starting a lawsuit, you must detect an act of infringement by your competitor, meaning their infringing activity must be visible using public information. To make enforcement easier, it’s wise to seek patent protection and craft claims for inventions where infringement is readily observable.

For inventions that involve difficult-to-detect elements, like internal cloud processes, a different approach, like trade secret protection, may be a better choice. Our patent lawyers can draft claims that cover easily detectable aspects for a more viable enforcement path.

Where to Bring a Patent Infringement Claim

Under United States law, patent holders can bring a patent infringement claim against alleged infringers for infringing use. Infringement actions arise under federal law, and the federal courts have exclusive jurisdiction.

However, certain patent issues can be brought in state court. For example, a dispute regarding the ownership of a patent or over a licensing agreement arises under property law or contract law, which are both generally dictated by state law. 

It’s a good idea to consult a patent attorney to understand your intellectual property rights for the applicable states, as well as your rights under federal law. This determines which venue is better suited for your specific infringement lawsuit. 

What Are the Common Defenses to Patent Infringement

As part of the process of presenting information to the factfinder on infringement, the defendant will often put on a defense to argue that its invention is not, in fact, infringing on the applicable patent. There are multiple patent infringement defenses, including:

• There is no actual infringement.
• The applicable patent is invalid.
• The applicable patent is unenforceable.

Factfinders must find that a patent claim has been infringed. In interpreting whether there has been infringement, the facts must be construed to establish if the patent claims have been infringed by the accused product.

How to Draft a High-Quality, Enforceable Patent

Because infringement can become an issue down the line for your patent, it’s helpful to draft your patent application with patent infringement lawsuits in mind.

1. Thoroughly Search for Prior Art

Make sure that you thoroughly research the potential prior art that is available. Draft claims and specifications in a way that distinguishes any prior art that may be similar to your claim.

Find the line between specificity and generality. Distinguish the prior art enough that you’re awarded the patent because your invention is sufficiently different. You don’t want to draft yourself into a corner that a court may then hold you to later, when in a lawsuit.

2. Construct Well-Written Claims With a Diverse Scope

An important step in legal protection is constructing well-written claims that precisely define what your patent covers. Your claims should feature a diverse scope, including both broad independent claims and narrower dependent claims.

This combination is strategic: broad claims make it harder for competitors to design around your invention, while narrower claims act as a safeguard against prior art invalidation. The ultimate aim is to secure at least one claim that is both broad enough for infringement and narrow enough to withstand any legal challenge to its validity.

3. Consult a Patent Lawyer

A well-written claim is very important to succeed in a patent lawsuit. Try to anticipate the areas where an outside individual will have questions or find something unclear or incomplete.

An experienced patent attorney will be able to help point out the areas of weakness in how your claims are drafted. Your attorney will also be able to suggest where and when to define terms, and when to allow terms to be left undefined because they are intuitive for the reader.

How to Develop an Enforcement Strategy

Developing a comprehensive enforcement strategy can maximize your patent portfolio’s value and deter future infringement. This is why our patent law services develop comprehensive strategies by analyzing case strength, identifying effective legal pathways, and negotiating settlements that serve an innovator’s commercial goals.

What Are the Compensations and Monetary Damages Awarded in a Patent Infringement Lawsuit

For successful infringement lawsuits, patent owners typically receive an award of damages from the infringer for the infringement of the patented invention. This damage award can be determined either by the factfinder at trial or by the court following a trial.

The financial stakes in U.S. infringement cases are enormous: the average defense cost is about $3.5 million, and royalty awards have historically surpassed $2.5 billion. Section 284 of the Federal Patent Act provides the underlying key framework for a damages award in an infringement lawsuit.

Damages must be the amount that will compensate for the infringement and must at least amount to reasonable royalties for the infringer’s use of the patented invention. The court can award up to three times the actual amount of damages incurred if the judge feels that the situation warrants it.

• Damages are awarded in the form of royalty payments for infringing on the patent. The infringing party would still be able to market the competing invention, yet would have to pay the holder a percentage of any profit that it makes. 
• You may also be eligible to recover what are called “lost profits”. Lost profits are the profits that you lost because of the infringing product.
• Another potential remedy for infringement is to obtain an injunction against the infringing product. This would prevent the infringing party from continuing to make and sell the infringing invention. An injunction is seen as a more extreme remedy by the court.

Related Questions

Is It Hard to Prove Patent Infringement?

Proving patent infringement can be difficult as it requires a precise comparison of the alleged infringing product or process to the detailed claims of the patent. The proof demands meticulous evidence and a sophisticated legal strategy. The expertise of our seasoned patent attorneys transforms intricate technical details into compelling legal arguments.

What Are the Criteria for Patent Infringement?

To constitute patent infringement, the accused product or process must fall within the scope of the patent’s claims. This means it must include every element (or a substantial equivalent) of at least one independent claim. Infringement can be direct, where the entire claimed invention is made, used, or sold, or indirect, which includes inducing infringement or contributing to it.

What Is Proof of Infringement?

Proof of infringement involves presenting sufficient evidence to the court demonstrating that the defendant’s activities directly or indirectly violate one or more claims of a patent. This evidence includes a detailed claim chart comparing the infringing product/process element-by-element with the patent claims. Documentation should also show the defendant’s commercial activities.

Can I Prove Infringement If I Have a Patent Pending?

You can’t sue for patent infringement while your application is merely “patent pending”. However, 35 U.S.C. § 154(d) allows provisional rights for royalties after publication of the application, if the infringer had actual notice and the issued claims are “substantially identical” to the published claims. The “patent pending” label itself often acts as a deterrent to competitors.

What Are Effective Mechanisms for Enforcing Intellectual Property Rights?

Effective mechanisms for enforcing intellectual property rights primarily include litigation for damages and injunctive relief, or seeking administrative remedies to block the importation of infringing goods. Patent lawyers can deploy these mechanisms by gathering the necessary evidence, constructing strong legal arguments, and representing the innovator.

Conclusion

With this knowledge of the elements of patent infringements, you can recognize when your rights are violated and take swift, informed action to protect your innovations and market position. The specialized guidance of experienced patent lawyers can help patent owners build claims upon the strongest legal and evidentiary foundation.