What is a Patent Claim Chart?

Claim Chart

A patent claim chart is commonly used in U.S. Patent infringement litigation. The claim chart is basically a visualization of all of the information analyzed in a patent claim. The purpose of a claim chart is to determine if any infringement has occurred. You can watch the presentation below for a quick tutorial on claim chat types, when they are used, and why they are used. The content below is a transcript of the video presentation and slightly expands upon the recorded information.

Watch a Quick 8-Minute Tutorial on Patent Claim Charts Below

The presentation above provides a brief introduction to Patent Claim Charts and how they are developed to evaluate intellectual property.

There are many different use cases for claim charts. Simply put, a claim chart is a tabular or graphical presentation that breaks a patent claim into its constituent elements, or limitations. For each element, evidences of use or prior art are presented. The goal of a claim chart is to systematically present the mapping between each claim limitation and the evidences of use, prior art, intent, etc.

Depending on the application of the claim chart, the evidences provided are usually to prove or analyze the use of the claimed invention in a product, service, or standard; the invalidity of the patent claim; or the intended meaning of each claim limitation, phrase, or word. For more information on GHB Intellect’s broader offerings, please navigate to our patent analysis services page.

A patent claim chart is simply an effective tool for analyzing and presenting information regarding a patent claim.

There is also a cousin of the claim chart, called a specification chart (or spec chart) that we do not discuss in the video above, but may present in a future presentation. Specification charts, instead of looking into the patent claims, we focus on the patent specification (or description).

A claim chart is used in a variety of patent evaluation cases: patent infringement analysis or litigation, Patent invalidity analysis or litigation, Patent licensing and marketing, & Claim construction arguments. For infringement analysis & litigation, claim charts help confirm or dis-confirm that each and every limitation of the claim is present in a product, service, or standard. For invalidity analysis in litigation, claim charts help confirm or dis-confirm the novelty of a claim relative to prior art.

Depending on the application, the level of detail and due diligence provided in a claim chart may vary significantly. For example, for marketing or licensing, far less due diligence is used than in court cases.

Claim charts have been required with IP court submissions since 1983 following the famous case: Summagraphics Corporation v. U.S. to help construct clear claim arguments. The court determined that “Partial Dismissal Order made clear this court’s intention that claims not delineated in plaintiff’s pretrial statement shall no longer be asserted in this case. ‘Plaintiff’s pretrial statement failed to include claim charts relating to the Nadon patent; thus, plaintiff shall also be precluded from asserting the Nadon patent at trial.'” Set as precedent, all litigation that occurs now includes detailed claim charts well before discovery has ended.

Although there are many different types of claim charts, three types are most prominent. An Evidence-of-Use (EoU) or Infringement Chart shows how a product or process accused of infringement contains each claim element to satisfy the ‘all elements test’ for infringement and is prepared by the plaintiff or patent owner. The all elements rule is a legal test used in US patent law to determine whether a patent claim lacks the novelty required to be valid and whether the combination of references relied upon shows obviousness for each claimed element.

An Invalidity Chart or Chart of References, shows invalidity of a patent due to anticipation or obviousness. It is prepared by a defendant or party accused of infringing on a patent. A Claim Construction or Claim Interpretation Chart, shows patent specification or technical literature citations with proper interpretations of the language of a claim and is prepared by both plaintiffs & defendants.

There are differing levels of patent claim chart sophistication and required due diligence depending on the intended use.

For internal use, preliminary research and analysis to detect potential infringement or prior art allows for quick review and is usually only a high-level presentation to internal decision-makers. Marketing uses generally include high-level mapping, which shows the potential for use to potential buyers or licensees. For Licensing or Sale purposes, Mid-level mapping and analysis are required and may include reverse engineering results. Sufficient details must be included to allow the potential buyer or licensee to determine the value and risk of the IP.

When it comes to assertion, defending patent rights or a product against an opposing patent claim is the goal. So, detailed mapping and analysis, including reverse engineering evidence is needed for legal negotiations between opposing parties. In court litigation, the highest level of due diligence and detail in terms of mapping, analysis, evidence presentation, and claim interpretations are required.

Claim charts can be presented in a number of formats. The most common formats are Table format and Graphical format. Typically, table format is a 2-column, sometimes 3-column, table in word processing software like Microsoft Word. The left column consists of rows of claim elements (usually separated in the claim by commas or semicolons). The second column contains evidences gathered regarding each claim element. The third column contains comments and arguments made regarding the claim elements correspondence and mapping to the evidences presented. If it’s a 2-column format, the comments are embedded along with the evidences in the 2nd column. However, care should be taken to make sure it is clear to the reader what is a comment and what is an excerpt from an evidentiary source.

The graphical format of a claim chart is typically presented in a slide deck where each slide highlights and focuses on one claim element or a part thereof. Evidences of use are shown on each slide and graphically mapped to the relevant parts of the claim element. Again, using very clear formatting differences, the comments are distinguished from the evidences.

As an example, the table format of an evidence of use chart would outline very specific claim elements like “a video processor for implementing communication between the video processor and a host CPU.”  The evidence is shown in separate reference sections – each with their own notes. Although this may seem simple, this would only be the first step of what can be a very long and incredibly specific process depending on the technology being used.

The important fact to keep in mind is that, ALL limitations (i.e., requirements) of a claim in a patent claim chart needs to be addressed and shown to be used in a product or service before one can conclude that a claim is being used (or infringed). As such, every word and phrase in the claim chart can be very important in this analysis and would need to be addressed.

When it comes to the graphical, or slide, format, each slide focuses on one claim element (the claim preamble is an exception and may be combined with the first element). If a claim element is rather long or complicated, multiple slides may be dedicated to completely map it. Each limitation is highlighted in the element using a different underlining or highlighting color. It is important to use the same color to identify the relevant evidence found to make it as easy for the reader as possible to follow the logic. We encourage you to watch the video above for an illustrative example of the two claim charts.

This is only a high-level presentation to get you familiar with the patent claim chart and how it is used in the intellectual property world. If you have further questions, about claim charts or the intellectual property services and expertise of GHB Intellect, please call us at (858) 367-3642.

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