Patent Claim Construction In India
1. Meaning and Importance of Claim Construction
Claim construction refers to the process by which courts interpret the scope and meaning of patent claims to determine:
Validity of the patent, and
Infringement by the defendant.
Under the Indian Patents Act, 1970, claims define the legal boundary of monopoly, while the specification explains the invention.
The patentee’s rights are confined strictly to what is claimed, not what is merely described.
2. Statutory Basis for Claim Construction in India
Although the Patents Act does not expressly define “claim construction,” it is implied from:
Section 10(4) – Claims must clearly and distinctly define the invention
Section 48 – Rights flow from claims
Section 59 – Amendments cannot enlarge claim scope
Indian courts rely heavily on English common law principles, but apply them with Indian statutory discipline.
3. Core Principles of Claim Construction in India
Indian courts consistently apply the following rules:
Claims are to be read as a whole
Specification can explain, not expand claims
Plain and ordinary meaning to technical terms
No importing limitations from description
Doctrine of purposive construction, not literalism
Prosecution history has limited relevance
What is not claimed is disclaimed
4. Landmark Indian Case Laws on Claim Construction
Case 1: Raj Prakash v. Mangat Ram Chowdhry (1977)
Facts:
Patent related to a demountable wheel rim
Defendant argued non-infringement by altering minor structural features
Issue:
Whether claims should be read literally or purposively
Court’s Reasoning:
Claims must be read with the specification, but not expanded
The essence of the invention lies in substance, not form
Minor variations that perform the same function may still infringe
Legal Principle:
Purposive construction adopted
The court rejected hyper-technical interpretation
Significance:
First Indian case clearly adopting purposive claim construction
Influenced later pharmaceutical and mechanical patent disputes
Case 2: Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries (1979)
Facts:
Patent for a pivot bearing used in utensils
Validity and scope of claims were challenged
Issue:
How strictly claims should be interpreted for validity
Court’s Reasoning:
Claims must be precise and unambiguous
Monopoly must not exceed what is clearly claimed
Any ambiguity must operate against the patentee
Legal Principle:
Claims define the monopoly
Courts cannot infer inventive merit beyond claims
Significance:
Established that claim construction impacts validity
Reinforced strict compliance with Section 10
Case 3: TVS Motor Company v. Bajaj Auto Ltd. (2009)
Facts:
Dispute over twin spark ignition engine patent
Both infringement and validity involved claim interpretation
Issue:
Whether features described but not claimed could be relied upon
Court’s Reasoning:
Claims are the heart of the patent
Courts cannot read into claims what the patentee omitted
Description may assist interpretation, not supplementation
Legal Principle:
No importing limitations from specification
What is not claimed is deemed abandoned
Significance:
Crucial precedent for mechanical and automobile patents
Strong warning against careless claim drafting
Case 4: F. Hoffmann-La Roche Ltd. v. Cipla Ltd. (2008)
Facts:
Patent for Erlotinib Hydrochloride (Tarceva)
Dispute over whether Cipla’s product fell within Roche’s claims
Issue:
How pharmaceutical claims should be interpreted
Court’s Reasoning:
Claims must be interpreted through the lens of a person skilled in the art
Technical terms must receive scientific meaning
Courts must avoid hindsight bias
Legal Principle:
Skilled person standard governs claim construction
Functional equivalence alone is insufficient without claim coverage
Significance:
Foundation for pharma patent claim interpretation
Balanced patentee rights with public interest
Case 5: Merck Sharp & Dohme v. Glenmark Pharmaceuticals (2015)
Facts:
Patent for Sitagliptin (anti-diabetic drug)
Defendant argued non-infringement based on salt form difference
Issue:
Whether different salt forms fall within the same claim
Court’s Reasoning:
Claim language must be read strictly
If claims specify a particular form, others are excluded
Doctrine of equivalents has limited application in India
Legal Principle:
Literal scope prevails over equivalence
Claim drafting precision is decisive
Significance:
Limited expansion through equivalence
Reinforced conservative Indian approach
Case 6: Enercon (India) Ltd. v. Aloys Wobben (2013)
Facts:
Multiple patents relating to wind turbine technology
Interpretation of overlapping claims
Issue:
How to construe claims when multiple embodiments exist
Court’s Reasoning:
Claims should not be interpreted to cover what the inventor did not invent
Each claim must stand on its own
Legal Principle:
No broad monopolies through vague claims
Claims must be technically and legally bounded
Significance:
Prevented abuse of broad functional claiming
Influential in technology patents
Case 7: Novartis AG v. Union of India (2013)
Facts:
Beta crystalline form of Imatinib Mesylate
Claim construction affected Section 3(d) analysis
Issue:
Whether claimed invention truly represented enhanced efficacy
Court’s Reasoning:
Claims must reflect real technical advancement
Mere drafting ingenuity cannot bypass statutory exclusions
Legal Principle:
Claim construction must align with substantive patentability
Claims cannot be interpreted in isolation from policy
Significance:
Integrated claim construction with public health considerations
5. Indian Position on Doctrine of Equivalents
Indian courts:
Acknowledge but rarely apply doctrine of equivalents
Prefer literal + purposive construction
Avoid US-style expansive interpretation
6. Summary of Indian Claim Construction Approach
| Aspect | Indian Position |
|---|---|
| Claims | Primary determinant |
| Specification | Explanatory, not enlarging |
| Interpretation | Purposive but cautious |
| Ambiguity | Against patentee |
| Equivalents | Limited acceptance |
| Public Interest | Strong influence |
7. Conclusion
Patent claim construction in India reflects a balanced approach:
Protecting genuine innovation
Preventing over-broad monopolies
Ensuring clarity, certainty, and public interest
Indian courts emphasize discipline in claim drafting, making claim construction a central pillar of patent litigation.
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