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Patent criticality
The case turns on what one word means
How can two engineers disagree about whether a product infringes?
Before anyone asks whether a product infringes, the court decides what the claim means. That single decision then governs both infringement and validity - which is why a construction wide enough to catch the defendant is often wide enough to be anticipated.
The squeeze
A patentee wants a broad construction, because it catches more products. A defendant is usually happy to accept it - and then point at prior art that also falls inside it.
That is the central discipline of patent litigation: you cannot argue one meaning for infringement and a narrower one for validity. Indian courts, applying purposive construction, read the claim through the eyes of the skilled person in the light of the specification and drawings, and expect consistency.
What drafting can do about it
Define terms explicitly. Use the same word for the same thing throughout. Avoid claim language whose natural width sweeps in the prior art you already know about. And be careful in prosecution: a construction adopted to overcome an objection tends to stick.
Section 48 of the Patents Act 1970 defines the rights by reference to the claims; construction is a matter of Indian case law.
Indian decisions have applied purposive rather than literal construction, and have looked at what a claim word would mean to the skilled person reading the specification as a whole.
Write a short definitions section. It is the cheapest litigation insurance available.
Arguing a wide meaning at the interim stage without checking what it does to validity.
Any claim term that appears only once in the specification.
Take your most important claim and write, for each term, the definition you would want a court to adopt. Then check the specification actually supports it.
Sources & further reading
- The Patents Act, 1970 (consolidated to 1 August 2024) — Official IP India text
- WIPO Patent Judicial Guide - India
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Not sure whether this applies to your invention?
The honest answer usually needs someone to look at your actual disclosure, your timeline and the prior art. That is a conversation, not an article.
Educational guidance, not legal advice. This material is published by Ragulika IP for general education and information. It is not legal advice, it does not create a professional-client relationship, and it is not a substitute for advice on your own facts. Patentability, infringement, prosecution strategy and every other IP outcome turn on the specific facts and on the law and Patent Office practice as they stand at the time you act. Please take professional advice before making a decision, and read the underlying provision or judgment before relying on any point stated here.
Last reviewed by Ragulika IP on 2026-08-23. Indian patent law and Patent Office practice change; check the position before you rely on it.