Doctrine Of Literal Infringement
Doctrine of Literal Infringement
1. Meaning of Literal Infringement
The Doctrine of Literal Infringement applies when a patented invention is infringed exactly as claimed in the patent specification.
➡️ If every essential element of a patent claim is found identically in the alleged infringing product or process, infringement is established, regardless of intent or minor differences.
This doctrine follows a strict, word-by-word comparison between:
the claims of the patent, and
the accused product/process.
2. Statutory Basis in India
Under the Patents Act, 1970:
Section 48 – grants exclusive rights to the patentee to prevent third parties from making, using, selling, or importing the patented invention.
Section 104–114 – deal with patent infringement suits.
Indian courts have consistently held that claims define the scope of monopoly, not the title or description.
3. Essential Elements Test (Core of Literal Infringement)
Courts apply the “all elements rule”:
✔️ Every essential feature mentioned in the claim must be present
❌ If even one essential feature is missing → no literal infringement
IMPORTANT CASE LAWS
1. Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries (1979, Supreme Court of India)
Facts
The plaintiff held a patent for a device used in manufacturing utensils. The defendant manufactured a similar device with minor structural changes.
Issue
Whether making slight changes avoids infringement when the core invention is the same.
Court’s Reasoning
Patent protection is confined strictly to what is claimed.
Courts must examine each claim element carefully.
If the defendant uses the same essential features, infringement occurs.
Ruling
The Court held:
Literal infringement occurs when the essential elements are copied exactly, even if minor changes are introduced.
However, since the patent lacked novelty, it was invalidated.
Legal Principle
📌 Claims are the heart of the patent, and literal infringement depends on exact claim matching.
2. Raj Prakash v. Mangat Ram Chowdhry (1977, Delhi High Court)
Facts
The plaintiff owned a patent for a mechanical device. The defendant argued that their product was different in appearance and size.
Issue
Does a difference in form avoid literal infringement?
Court’s Reasoning
What matters is functional identity, not cosmetic changes.
The court examined whether each claim element was present.
Ruling
The defendant’s product contained every essential claim element → infringement established.
Legal Principle
📌 Literal infringement focuses on substance over form.
3. F. Hoffmann-La Roche Ltd. v. Cipla Ltd. (2008, Delhi High Court)
Facts
Roche owned a patent for the cancer drug Erlotinib. Cipla produced a generic version claiming differences in formulation.
Issue
Whether Cipla’s drug literally infringed Roche’s patent.
Court’s Reasoning
Compared the chemical composition claim-by-claim.
Found Cipla’s product contained the same compound as claimed.
Ruling
Literal infringement was established.
Cipla’s argument of affordability was irrelevant to infringement.
Legal Principle
📌 Exact chemical identity leads to literal infringement, regardless of pricing or intention.
4. Merck Sharp & Dohme v. Glenmark Pharmaceuticals (2015, Delhi High Court)
Facts
Merck held a patent over Sitagliptin, an anti-diabetic drug. Glenmark launched a generic version.
Issue
Whether Glenmark’s product contained all elements of the patented claim.
Court’s Reasoning
Applied claim-by-claim analysis.
Found that Glenmark used the same salt and molecular structure.
Ruling
Literal infringement confirmed.
Injunction granted against Glenmark.
Legal Principle
📌 If a product falls squarely within the claim language, infringement is automatic.
5. TVS Motor Company v. Bajaj Auto Ltd. (2009, Supreme Court of India)
Facts
Bajaj held a patent for a DTS-i engine technology. TVS developed a similar engine with slight design variations.
Issue
Whether TVS’s engine literally infringed Bajaj’s patent.
Court’s Reasoning
Courts must check whether all claimed features exist together.
Emphasized prima facie claim construction at interim stage.
Ruling
No clear literal infringement at interim stage.
Suit allowed to proceed for full trial.
Legal Principle
📌 Literal infringement requires complete presence of all essential features, not partial similarity.
6. Catnic Components Ltd. v. Hill & Smith Ltd. (House of Lords)
(Often relied upon by Indian courts)
Facts
Patent required a steel beam “vertically aligned”. Defendant used a beam tilted slightly.
Issue
Does strict literal interpretation apply?
Ruling
Literal meaning must be understood practically, not mechanically.
Slight deviation did not avoid infringement.
Legal Principle
📌 Literal infringement must be assessed with purposive construction, not hyper-technical reading.
7. Lallubhai Chakubhai v. Chimanlal & Co. (1935, Privy Council)
Facts
Concerned copying of patented textile machinery.
Ruling
If the defendant takes the substance of the invention, literal infringement is established.
Legal Principle
📌 Literal infringement exists when the entire claimed invention is taken, even if disguised.
Key Legal Principles Derived
Claims define the monopoly, not descriptions or drawings.
All essential elements must be present for literal infringement.
Minor changes or cosmetic differences do not defeat infringement.
Courts follow claim-by-claim comparison.
Literal infringement is distinct from the Doctrine of Equivalents.
Intention or motive is irrelevant.
Chemical and pharmaceutical patents attract strict literal scrutiny.
Difference Between Literal Infringement and Doctrine of Equivalents
| Literal Infringement | Doctrine of Equivalents |
|---|---|
| Exact claim matching | Substantial similarity |
| Strict interpretation | Flexible interpretation |
| No missing elements allowed | Minor differences allowed |
| Easier to prove | Harder to prove |
Conclusion
The Doctrine of Literal Infringement ensures certainty and predictability in patent enforcement. Indian courts consistently emphasize that patentees are protected strictly within the boundaries of their claims, and any unauthorized reproduction of all essential elements constitutes infringement.
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