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  • Writer's pictureRobert Cantrell


Updated: Aug 23, 2022

August 16, 2022

By Robert Cantrell - Registered Patent Agent

One of the things that attracted me to the art of patent drafting is its adherence to relevance. You cannot leave any word out relevant to your claims nor include a word that is irrelevant to your claims (unless required to distinguish your invention from the prior art), yet every word may be used against the interpretation of your claims.

I once received a patent application draft from outside counsel when I was inventing at Walmart that described a camera we used to read bar code labels as a high-resolution camera without defining what the term “high-resolution” meant. I had not used the term in my invention disclosure. The qualifier could have undermined our claims. High-resolution can mean one thing to one person and something else to another, for example, a consumer camera user, a supply chain engineer, and an engineer at NASA. Standards may also change over time. So, the better choice in such circumstances is to omit the qualifier given that a person of ordinary skill in the art would recognize the camera must have enough resolution to do the job. Alternatively, you could provide the minimum resolution required. “High” becomes an irrelevant term.

Relevance pertains to scope and whether a qualifier describes a characteristic necessary for a function and one that may be needed to distinguish the claim over the prior art. If a rod, for example, must be cylindrical for an invention to function, then calling it a cylindrical rod makes sense. Otherwise, just calling it a rod will do. To add cylindrical when unneeded creates a way to design around the claims. But you don’t stop there. Such qualifiers, when presented by inventors, should also prompt you to ask whether cylindrical is the only way to achieve the function. If other shapes work, you may want to include them or, at least, avoid excluding them. You seek relevance both in the terms and the engineering.

If a qualifier matters, include it. If irrelevant, leave it out. If in doubt, make it representative and apart from the broader claims. And steer way from terms such as high that may be interpreted differently from the way you intended unless you also define the term in your specification.


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