Importance, Purpose, Processes and Methods of Patent Claim Charts and Construction

What is Patent Claim Chart?

In general, a Patent Claim describes the extent to which the subject matter of a patent application is protected, as well as the things that are not covered by the claim.


The patent claim chart is primarily used in patent infringement cases. In each row of a claim chart, which has at least two columns, one for elements and the other for construction, the claims are broken down into elements.


The content and number of the necessary columns can change depending on the interpretation, the allegedly infringing product or practice, and further examination.


What is Patent Claim Construction?

The process of analyzing and interpreting existing patent claims to match them to an infringing product or technique is known as claim construction. Claim constructions differ from one situation to the next, therefore they cannot be utilized interchangeably.


The Purpose of Patent Claim Construction

Patent claim construction is most commonly employed in legal contexts, but it can also be applied in non-legal situations.


Although claim construction is most commonly seen and employed in patent infringement cases, it can also be used in a variety of non-litigation situations. Litigation issues and non-litigation issues can be loosely divided into claim formulation purposes.


Litigation issues

In each infringement case, claim construction is regarded as the most important issue. It evaluates a patent’s claims and establishes the patent’s scope, establishing the case’s foundation. It can also be used as a pre-litigation tool. For example, you may draft an informal claim construction and threaten to sue infringers.


Non-litigation issues

Claim construction is crucial in analyzing the breadth of the patent and its link to new or existing products for monetization, such as selling/acquisition and licensing (particularly from the licensee’s perspective). If you want to license a patent from a corporation, you’ll need to know what their patent claims cover and how much they cost. This also works if you’re looking at a competitor’s patent scope and product coverage as part of a patent landscaping or market probing exercise.


Methods of claim construction

There are two steps:

Interpreting the claims in the patent

Identifying the viewpoint—for example, in the United States, this is done to identify a person with ordinary skill in the art (PHOSITA). Judge MayKleer must determine “who” the PHOSITA is and his or her level of expertise. If the patent in question claims a device that detects gas leaks in a space shuttle, the PHOSITA would need to be conversant with spaceship engineering and prior art. If the device is for detecting gas leaks from gas stoves, the PHOSITA description and level of competence would be substantially different, with someone who is a kitchen appliance mechanic or designer being the most likely candidate.

It’s essential to clear any uncertain terms — if there are any doubts or unclear statements the judge may consider them invalid.


Claim comparisons with the required infringing process or product

Once the judge has all the clear data indicating the patent’s claims are paraphrased version to that of the accused infringing product (or process) this step can be executed.


What is a claim chart?

A claim chart, as we saw in Judge’s case, is a chart used to assess patent claims and compare them. The claims are deconstructed into elements in each row of a claim chart, which has at least two columns. From the interpretation or interpretations, through the alleged infringing product or process, to additional examination, the content and number of right columns can vary.


The basis for a case is a claim chart prepared by the court for infringement litigation. These records are private and extremely difficult to obtain. Because of the sensitive information that will appear in the chart, the chart itself is excluded even in public opinion. For example, a chart can include the software’s source code, which should not be made public. Here is an example of a claim chart used in litigation:


There are various other reasons for which a Claim chart is constructed like reexamination during the prosecution stage by the PTO  or reviewing the patent’s validity by PTAB’s. Here we can see a petitioner color-coding to explain each of the components in the claim for a reexamination of the patent.


One more common example is the design comparisons that take place for design patents. In this stage, it is not necessary to compare the claims, but pictures.


Broadly speaking, claim charts can be used for any purpose regarding patent claim analysis and interpretation.



The broad rules for patent claim construction are discussed in this article, as there are still some disagreements about how to approach claim construction. This is especially true in the United States, where the legal system is based on case law. On how to interpret claims, we frequently observe inconsistencies between district court judgments, Federal Circuit Court decisions, and Supreme Court decisions. Perhaps, in the future, claim construction in litigation will be more clear and systematic.