Claim Chart – An Useful Patent Tool

Claims form the most important part of a patent as the rights of a patentee reside in them.

Should a person utilize an invention, without the permission of the patentee, he may infringe that patent. The issue of infringement is country specific, that is to say, the technology (device or process) as in the invention of the patent should not be utilized without the permission of the patentee, in that particular country where the patent exists.

The infringement test differs from country to country, but, in general, infringement is said to have occurred when the infringer’s product (device, process, service, etc) falls within one or more of the claims of the granted patent. This requires “reading” a claim onto the technology of interest (‘accused product’). If all of the claim’s elements are found in the ‘accused product’, the claim is said to “read on” the technology; if a single element from the claim is missing from the ‘accused product’, the claim does not literally read on the technology and the ‘accused product’ does not infringe the patent with respect to that claim.

An useful patent tool in this context is the ‘Claim Chart’.

Basically, the claim chart is a two-column table, where the left side column contains the claims (broken down into component elements) and the right side column contains ‘Yes’/ ‘No’. The procedure includes splitting each of the independent claims into component elements and each element then is compared with the ‘accused product’. ‘Yes’/ ‘No’ indicates if the element referenced on the left side is available/ contained or not within the ‘accused product’. A single ‘No’ in this comparison chart can bail out the product from accusation of infringement with respect to the claim that is compared.

One of the many reasons for rejection of a patent before grant or for invalidation of the patent after grant is ‘Non-enablement’. A patent claim must be properly described in the patent specification which is called ‘enablement’. As such, in claim charting, the claim components are referenced with the text in the patent specification and then compared for in the ‘accused product’.