Key Takeaways

  • A patent claim chart is a structured tool that maps each element of a patent claim to features of a product or process.
  • Claim charts are used in litigation, licensing, due diligence, and negotiations, helping clarify complex technical and legal issues.
  • There are different types of claim charts, including infringement charts and invalidity charts, each serving distinct purposes.
  • Properly prepared claim charts can strengthen legal strategy, but poorly drafted ones may weaken a case.
  • Common mistakes include being overly broad, failing to include claim language, or neglecting visual aids where helpful.
  • Claim charts must balance legal accuracy with clarity so that judges, juries, and business executives can understand them.

Claim Charts: What Are They?

A claim chart is used to show how a product (or a service) has infringed on a patent, typically a utility patent. To prove the case, the patent owner must show that the product or service in question infringes on every portion of the claims. Claim charts break down complicated claims into easily read arguments that both parties can use when deciding a case. They also make it easier to compromise and negotiate with the other side.

The claim chart breaks down a claim by its specific elements. It doesn't have to cover the entire patent claim, and can only focus on the parts of the claim that are valid. Most lawyers agree that the claim chart is only as good as the claims that it contains. If it does not contain all the claim language, a court cannot determine whether infringement has taken place.

Claim charts have multiple names. Within a court of law, prosecutors might refer to them as:

  • claims tables
  • infringement contentions (ICs)
  • invalidity contentions
  • preliminary infringement contentions (PICs)

While they go by many names, claim charts have been required with court submissions since the 1983 case of Summagraphics Corporation v. U.S..

There are differnt types of claim charts. Generalized ones are typically used in licensing strategies. More sophisticated charts are used to demonstrate infringement and to determine possible interpretations of the claims when legal teams prepare to file a lawsuit.

Types of Patent Claim Charts

Patent claim charts are not one-size-fits-all; they vary depending on the purpose of the legal matter. The two most common types are:

  • Infringement Claim Charts – These charts demonstrate how each element of a patent claim is found in the accused product or service. They are often submitted during litigation to show that every component of the patented invention has been copied.
  • Invalidity Claim Charts – These charts aim to prove that a patent is not valid. They typically compare the patent’s claims to prior art, showing that the claimed invention was already known or obvious.

Other variations include licensing claim charts, which are used during negotiations to illustrate the strength of a patent portfolio, and due diligence charts, which are prepared during mergers or acquisitions to evaluate intellectual property assets.

Why are Claim Charts Important?

Claim charts make it easy for people in the courtroom to understand what patents are being violated. Between technological and medical inventions, patents are becoming more complicated. This means court members need to fully understand the products before they can decide which side wins the case. Claim charts make it easy to learn about the different industry jargon before sitting through a case.

The modern criteria that a claim chart needs to prove that a claim was violated and a patent was infringed upon. Each claim chart needs to explain:

  • Which specific claims have been infringed
  • Which products or processes did the defendant make from the patent
  • Exactly where each element of the claim is found in the defendant's products

For example, an inventor might patent a motor that sits in the back of a machine and pumps out air. The legal team would need to find a company that used the same (or similar) motor design in the same way that the inventor intended. If they can't prove this, then the patent use might just be coincidence instead of a violation.

How Patent Claim Charts Are Prepared

Preparing a strong claim chart requires both legal and technical expertise. Attorneys or patent experts usually follow these steps:

  1. Break Down the Patent Claims – Each claim is divided into individual elements or limitations.
  2. Identify Corresponding Product Features – The accused product or prior art reference is analyzed to determine whether it contains each element of the claim.
  3. Provide Supporting Evidence – Evidence may include technical documents, schematics, photographs, or user manuals.
  4. Organize in a Two-Column Table – The left column typically lists claim language, while the right column maps that language to the product or prior art.
  5. Add Visual Aids – Diagrams, screenshots, or annotated images may be included to make the comparison easier for judges and juries.

Thorough preparation ensures the claim chart is credible and withstands scrutiny during litigation or negotiations.

Reasons to Consider Using Claim Charts

Claim charts aren't just for the prosecution's use in trying to prove that another company stole the plaintiff's idea. They're also invaluable for the defense. A company that has been accused of stealing an idea can use claim charts to prove that it did not take someone else's ideas.

These charts can also keep infringement claims out of the courtroom. Claim charts open up the idea of negotiations, and a company might use them to negotiate a patent claim. Instead of a lengthy trial or expensive payout, both parties may be happy to make compromises and come to a settlement based on their own needs.

Claim charts strengthen overall litigation efforts. Well-written claim charts can help you win cases, which can set a precedent against any future claims. As you take on multiple cases and push companies into negotiations, you can use past precedents to win your case.

Strategic Uses of Patent Claim Charts

Beyond courtroom litigation, patent claim charts serve several important business and legal purposes:

  • Negotiations & Licensing – Companies use claim charts to show competitors how their products may infringe patents, encouraging licensing agreements instead of lawsuits.
  • Patent Valuation – Investors and acquirers review claim charts during due diligence to assess the strength of a company’s intellectual property portfolio.
  • Litigation Strategy – Defense attorneys use invalidity charts to challenge patents, while plaintiffs rely on infringement charts to demand damages.
  • Portfolio Management – Corporations with large patent portfolios use claim charts to decide which patents are enforceable and worth maintaining.

Examples of Claim Charts

For those who are new to the claims process, every claim chart should be two columns wide and several rows deep. In each of the rows in the first column, you would break down different elements of the patent so that you could defend which parts had been infringed.

Once this chart is created, both legal teams will go line-by-line to prove that the item described is in fact what the claim says it is and that it's a violation of the patent.

Naturally, this is just one example of a claim chart, and there are other options that your legal team would choose to follow instead. However, there are common threads in every claim chart. Here is the information every claim chart needs:

  • A diagram breaking down the claims and what is contested
  • Elements of the claim that make up the patent
  • Patent integers (or the number associated with the patent)
  • Parts of the product or machine that have been violated
  • Details proving that the parts were taken from the patent and used by the defendant

Oftentimes it's not enough to prove that the parts are similar in order to win the case. The plaintiff needs to prove that the other party directly stole his or her idea and used it to make a profit.

Best Practices for Drafting a Claim Chart

Effective claim charts follow certain best practices to ensure they are persuasive:

  • Use Clear Language – Avoid jargon where possible, and explain technical terms so that non-experts can understand.
  • Be Specific – Point to exact locations in the accused product or prior art, including page numbers, line references, or labeled diagrams.
  • Maintain Consistency – Each claim element should be addressed in the same format for clarity.
  • Balance Detail with Clarity – While comprehensive, charts should avoid becoming cluttered or confusing.
  • Anticipate Counterarguments – A well-drafted chart includes evidence that addresses potential defenses.

Common Mistakes with Claim Charts

The use of claim charts in court date back to 1937, where the plaintiffs of Christensen v. Bragg-Kliesrath Corporation used charts to easily interpret the different claims and how they had been violated. The charts and in-depth analysis actually lead the plaintiffs to drop the case so they could add more claims to the patent. In the past 80 years, legal teams have become smarter about the claim charts they create, but there's still room for error within them.

One of the main risks that come with drafting claim charts is that you could create something that's too broad. One great example of a claim chart that was too broad: The patent was for a motorcycle and claimed that any vehicle with the following specifications would qualify as a motorcycle:

  • An engine
  • Two wheels
  • A transmission attached to at least one wheel
  • A transmission meant to use energy to rotate at least one wheel

While the above criteria certainly describes a motorcycle, it also describes a moped and a motor scooter. The inventor would be hard pressed to prove that all three of those vehicles were the same and were covered by his patent. This is what happens when the claim chart is too broad.

Another mistake is including all the details in one paragraph. Should the claim run into the hundreds of words, single words that could be significant to the claim might be overlooked.

Frequently Asked Questions

1. What is the main purpose of a patent claim chart?

A patent claim chart is used to map patent claims to a product or process, typically to prove infringement or invalidity.

2. How do infringement and invalidity claim charts differ?

Infringement charts show how a product copies patented features, while invalidity charts demonstrate that a patent is not valid by comparing it to prior art.

3. Who typically prepares patent claim charts?

They are usually prepared by patent attorneys, technical experts, or litigation teams with both legal and industry knowledge.

4. Can claim charts be used outside of court?

Yes. They are often used in licensing negotiations, due diligence, and portfolio valuation to assess patent strength.

5. What makes a claim chart effective?

Clarity, accuracy, supporting evidence, and strong visual aids are key to ensuring the chart persuades judges, juries, or business partners.

Companies that are unfamiliar with the claims process should Post your legal need here to get free custom quotes from the top 5% of lawyers on creating a claim chart. A lawyer's expertise should make it easier to create compelling pieces of evidence that can help your business win claims.