Infringement of Patents and Remedies for Infringement of Patents

A patent is a statutory right granted to an inventor for a limited period in respect of a new and useful invention. It confers an exclusive right to prevent others from making, using, selling, offering for sale or importing the patented product or process without authorisation. In India, patent protection is governed by the Patents Act, 1970, as amended.

The grant of a patent is not merely recognition of innovation. It is a legally enforceable monopoly for twenty years from the date of filing, subject to payment of renewal fees. However, the value of a patent lies not only in its registration but in its enforceability. When unauthorised use occurs, it amounts to patent infringement, and the law provides structured remedies.

This article provides a detailed overview of the concept of patent infringement, types of infringement, burden of proof, recognised doctrines, defences and remedies available under Indian law.

Meaning of Patent Infringement

Patent infringement occurs when a person, without the consent of the patentee, performs any act that falls within the exclusive rights granted under Section 48 of the Patents Act, 1970.

Under Section 48:

• In case of a product patent, the patentee has the exclusive right to prevent third parties from making, using, offering for sale, selling or importing the patented product in India.
• In case of a process patent, the patentee has the exclusive right to prevent third parties from using the process and from using, offering for sale, selling or importing the product directly obtained from such process.

If any of these acts are carried out without licence or authorisation during the term of the patent, infringement arises.

Types of Patent Infringement

Patent infringement may be classified into different categories depending upon the nature and manner of violation.

Direct Infringement

Direct infringement is the most common form of patent infringement. It occurs when a person directly performs an act that is exclusively reserved for the patentee under Section 48.

Acts constituting direct infringement include:

• Manufacturing the patented product.
• Using the patented process.
• Selling or offering for sale the patented invention.
• Importing the patented product into India.

Direct infringement may be intentional or unintentional. Intention is not a necessary element; the mere performance of the infringing act during the validity of the patent is sufficient.

Literal Infringement

Literal infringement is a form of direct infringement where each and every essential element of a patent claim is copied exactly.

In such cases:

• The accused product or process contains all features described in the patent claims.
• There is no substantial deviation.
• The comparison is done strictly on claim language.

If all elements of the claim are present in the accused product, literal infringement is established.

Non-Literal Infringement (Doctrine of Equivalents)

Non-literal infringement occurs where the accused product does not copy the patent word-for-word but performs substantially the same function, in substantially the same way, to achieve substantially the same result. This is recognised under the Doctrine of Equivalents.

Indian courts apply the “Triple Identity Test”:

• Same function
• Same way
• Same result

If these three conditions are satisfied, infringement may be established even if there are minor changes in form, name or structure.

In Ravi Kamal Bali v. Kala Tech (2008), the court applied this doctrine and held that slight variations which do not amount to innovation cannot defeat patent protection.

Indirect Infringement

Indirect infringement arises when a person contributes to or facilitates infringement by another party.

Although the Patents Act does not explicitly define contributory or induced infringement, courts recognise such liability based on principles of aiding and abetting.

Induced Infringement

Induced infringement occurs when a person knowingly encourages or assists another to infringe a patent. This may include:

• Providing instructions for manufacturing the patented product.
• Licensing an infringing process.
• Assisting in assembly or production.

Liability arises where there is active participation or encouragement.

Contributory Infringement

Contributory infringement occurs when a person supplies a component that is specially designed for use in a patented invention and has no substantial non-infringing use.

Even if the supplier does not directly manufacture the final product, liability may arise if the component is exclusively meant for infringement.

Wilful Infringement

Wilful infringement refers to deliberate and conscious violation of patent rights.

Although the Indian statute does not provide for enhanced damages in the same manner as some other jurisdictions, courts may consider intentional conduct while determining compensation and costs.

Burden of Proof in Patent Infringement

Generally, the burden of proof lies on the patentee (plaintiff). The patentee must establish:

• Existence of a valid patent.
• Ownership of the patent.
• Acts of infringement by the defendant.

However, Section 104A of the Patents Act introduces the concept of reversed burden of proof in cases involving process patents.

Under Section 104A, if:

• The patent relates to a process for obtaining a new product, or
• There is substantial likelihood that the identical product is made by the patented process and the patentee cannot determine the process used by the defendant despite reasonable efforts,

then the court may require the defendant to prove that the process used is different.

This provision strengthens enforcement in process patent cases.

Doctrines Related to Patent Infringement

Doctrine of Equivalents

This doctrine prevents infringers from escaping liability by making minor or insubstantial changes.

If the core inventive concept is appropriated and the accused product performs substantially the same function in the same way to achieve the same result, infringement may be established.

Limitations to the Doctrine

The doctrine is not unlimited. Courts consider:

• All Elements Rule – All essential features of the claim must be present.
• Public Dedication – If a patentee discloses but does not claim certain subject matter, it becomes public property.
• Existence of Prior Art – The doctrine cannot expand protection beyond what is novel.
• Prosecution History Estoppel – Amendments made during patent prosecution to overcome objections may restrict later claim interpretation.

Doctrine of Colourable Variation

Derived from the maxim “Quando aliquid prohibetur ex directo, prohibetur et per obliquum”, this doctrine states that what cannot be done directly cannot be done indirectly.

Minor cosmetic changes intended to disguise infringement are treated as colourable variations.

Courts examine:

• Degree of similarity.
• Functional resemblance.
• Intention behind modification.
• Technical complexity.
• Evidence of copying.

In Pfizer Inc. v. Cadila Healthcare Ltd (2020), the Supreme Court recognised that slight structural variations which do not change essential characteristics may still amount to infringement.

Acts That Do Not Amount to Patent Infringement

The Patents Act, 1970 recognises that not every use of a patented invention amounts to infringement. Certain acts are either statutorily permitted or legally justified. These exclusions balance the rights of the patentee with public interest, research freedom and commercial certainty.

The following acts generally do not amount to patent infringement under Indian law:

Independent Invention

Independent invention refers to a situation where a person develops a product or process without copying or referring to the patented invention.

• The accused party must demonstrate that the invention was created through independent research and development.
• Evidence such as laboratory records, research documentation, prototypes, dated correspondence or technical reports may be relied upon.
• The development must have occurred without access to or knowledge of the patented invention.

However, it must be noted that patent infringement in India is primarily claim-based. If the independently developed product falls within the scope of the patent claims, infringement may still arise regardless of intention. Therefore, independent invention does not automatically defeat infringement if the patented claims are substantially covered.

Expiry of Patent

A patent in India is valid for twenty years from the date of filing, subject to payment of annual renewal fees under Section 53 of the Patents Act.

• Once the statutory term expires, the exclusive rights of the patentee come to an end.
• The invention enters the public domain.
• Any person may make, use, sell or import the invention without seeking permission.

No infringement action can be maintained after expiry of the patent. The accused party may establish the expiry by producing patent records and demonstrating that the statutory term has concluded.

Experimental or Research Use

Use of a patented invention for experimental or research purposes may not amount to infringement, particularly where there is no commercial exploitation.

• The use must be genuinely for research, testing or evaluation.
• It should not involve sale or commercial distribution of the patented product.
• The purpose must be scientific inquiry or academic advancement.

Additionally, Section 107A of the Patents Act recognises the “Bolar exception”. It permits use of a patented invention for purposes reasonably related to development and submission of information required under any law regulating manufacture, use or sale of any product. This is particularly relevant in pharmaceutical research for obtaining regulatory approvals.

Such limited experimental use is treated as a lawful exception and does not constitute infringement.

Government Use

The Patents Act allows the Central Government to use patented inventions for public purposes under specific conditions.

• The government may authorise use of a patented invention for public interest, national security, public health or essential services.
• Such use must comply with statutory provisions and may require payment of reasonable compensation to the patentee.
• The use must be for governmental purposes and not purely commercial gain.

This exception ensures that public welfare considerations are not obstructed by exclusive patent rights.

Prior Use

Prior use refers to a situation where a person was already using the invention before the date of filing of the patent application.

• The accused party must establish continuous and bona fide use before the priority date.
• Documentary evidence such as invoices, production records, sales records or technical documents may be required.
• The use must not have been derived from the patentee.

In such cases, limited rights may continue for that prior user, depending on the facts and judicial interpretation. The principle protects those who were genuinely practising the invention before patent protection arose.

First Sale Doctrine (Doctrine of Exhaustion)

The doctrine of exhaustion, commonly referred to as the first sale doctrine, limits the patentee’s control over a patented product after its lawful sale.

• Once a patented product is sold by the patentee or with authorisation, the patent rights in respect of that specific article are exhausted.
• The purchaser may use, resell or distribute that product without further permission.
• The patentee cannot impose restrictions on subsequent resale unless protected by contractual terms.

This doctrine promotes free movement of goods and prevents perpetual control over lawfully sold products.

Invalidity or Unenforceability of the Patent

If a patent is found to be invalid, infringement cannot be established.

• A patent may be challenged under Section 64 on grounds such as lack of novelty, obviousness, insufficient disclosure or non-patentable subject matter.
• If the court declares the patent invalid, the exclusive rights cease to exist.
• Any act that would otherwise have been infringing becomes lawful.

Invalidity operates as a complete defence. Since infringement presupposes the existence of a valid patent, absence of validity eliminates liability.

Defences Available Against Patent Infringement

In a suit for patent infringement, the defendant is entitled to raise various statutory and equitable defences. The Patents Act, 1970 provides a structured mechanism through which validity of the patent and enforceability of rights may be challenged. These defences ensure that patent rights are exercised within legal boundaries and are not misused.

Invalidity of Patent (Section 64 read with Section 107)

One of the strongest defences available in an infringement suit is a challenge to the validity of the patent itself.

Under Section 107 of the Patents Act, every ground on which a patent may be revoked under Section 64 can be raised as a defence in an infringement suit. This means that the defendant can argue that the patent should never have been granted in the first place.

Common grounds of invalidity include:

(a) Lack of Novelty

A patent must relate to a new invention. If the invention was previously known, used or published anywhere in the world before the priority date, it lacks novelty. Evidence of prior publication or prior public use may invalidate the patent.

(b) Obviousness (Lack of Inventive Step)

The invention must involve a technical advancement or economic significance and must not be obvious to a person skilled in the art. If the improvement is merely a workshop modification or a predictable variation, the patent may be invalid.

(c) Prior Publication

If the invention was disclosed in any document, journal, patent specification or public domain before the filing date, it may destroy novelty.

(d) Insufficient Disclosure

The patent specification must clearly and completely describe the invention and the method of performing it. If the disclosure is vague or incomplete, the patent may be revoked.

(e) Non-Patentable Subject Matter

Certain inventions are excluded under Sections 3 and 4 of the Patents Act. If the subject matter falls within these exclusions, such as mere discovery or abstract theory, the patent may be invalid.

If the court accepts any of these grounds, the patent may be declared invalid, and infringement proceedings will fail automatically.

Estoppel

Estoppel is an equitable defence based on conduct.

If the patentee has, by words or actions, represented that certain use of the patented invention is permitted, later assertion of infringement may be restricted. This may arise in situations where:

• The patentee allowed use of the invention for a significant period without objection.
• The patentee made representations that induced reliance.
• There was acquiescence or implied consent.

In such circumstances, courts may prevent the patentee from asserting infringement if it would be inequitable to do so.

Licence

If the defendant possesses a valid licence from the patentee, no infringement arises.

A licence may be:

• Exclusive
• Non-exclusive
• Express or implied

The defendant must establish the existence and scope of the licence agreement. If the acts complained of fall within the terms of the licence, infringement cannot be sustained.

Compulsory licences granted under statutory provisions also operate as a valid defence.

Lack of Standing

Only a person with legal authority may institute a suit for infringement.

Under the Patents Act:

• The patentee has the primary right to sue.
• An exclusive licensee may also sue under certain conditions.
• A non-exclusive licensee generally cannot sue independently.

If the plaintiff does not hold valid ownership, assignment or statutory entitlement, the suit may fail for lack of locus standi.

Remedies for Patent Infringement

Remedies for infringement are governed primarily by Section 108 of the Patents Act, 1970. These remedies are designed to both prevent continued infringement and compensate for loss suffered.

Injunction

An injunction is a judicial order restraining the defendant from continuing infringing acts. It is the most important remedy in patent litigation.

(a) Temporary (Interim) Injunction

An interim injunction is granted during the pendency of the suit to preserve the status quo until final adjudication.

Courts consider three essential factors:

• Prima Facie Case – The plaintiff must demonstrate a credible case showing validity of patent and probable infringement.
• Balance of Convenience – The court weighs comparative hardship to both parties.
• Irreparable Injury – There must be risk of harm that cannot be adequately compensated by monetary damages.

Interim injunctions are crucial in industries where delay may lead to permanent market loss.

(b) Ex-Parte Injunction

An ex-parte injunction is granted without hearing the defendant in urgent circumstances.

• It is issued where delay may defeat the purpose of litigation.
• The plaintiff must disclose all material facts fully and honestly.
• Courts exercise this power cautiously due to its immediate impact on the defendant.

Such injunctions are temporary and subject to confirmation after hearing both sides.

(c) Permanent Injunction

A permanent injunction is granted after final adjudication when infringement is conclusively proved.

• It permanently restrains the defendant from manufacturing, selling or using the patented invention.
• It confirms the enforceability of patent rights.

Permanent injunctions safeguard the monopoly granted under the patent.

Damages

Damages aim to compensate the patentee for financial loss caused by infringement.

The objective is compensatory rather than punitive. Courts may assess:

• Loss of profits suffered by the patentee.
• Reduction in market share.
• Price erosion.
• Impact on goodwill.

The court may award damages based on reasonable royalty if actual loss cannot be precisely quantified.

Account of Profits

Instead of claiming damages, the plaintiff may elect an account of profits.

• This remedy requires the defendant to disclose profits earned from infringement.
• The profits attributable to infringement may be awarded to the patentee.
• It prevents unjust enrichment.

The plaintiff cannot claim both damages and account of profits simultaneously.

Seizure, Forfeiture or Destruction

Courts may order that infringing goods and materials be:

• Seized and taken into custody.
• Forfeited.
• Destroyed or delivered to the patentee.

This remedy ensures removal of infringing goods from the market and prevents continued circulation.

Landmark Judgements on Patent Infringement in India

Judicial precedents have significantly shaped patent enforcement in India.

Novartis AG v. Union of India (2013)

In Novartis AG v. Union of India, the Supreme Court examined the concept of enhanced efficacy under Section 3(d) of the Patents Act.

The case involved a pharmaceutical product claimed as a new form of an existing substance.

The Court rejected the patent application on the ground that it did not demonstrate enhanced therapeutic efficacy. The judgement prevented “evergreening” of patents through minor modifications.

Although not a traditional infringement case, the decision clarified standards of patentability and strengthened scrutiny of pharmaceutical patents in public interest.

Telefonaktiebolaget LM Ericsson v. Intex Technologies (2014)

Telefonaktiebolaget LM Ericsson v. Intex Technologies case involved Standard Essential Patents (SEPs) relating to telecom technologies.

The Delhi High Court recognised infringement of Ericsson’s patents. It addressed the principle of FRAND (Fair, Reasonable and Non-Discriminatory) licensing.

The court ordered payment of royalties. The case established important principles on technical evidence, interim relief and balancing of equities in technology patent disputes.

Bajaj Auto Ltd. v. TVS Motor Company Ltd. (2009)

This dispute concerned alleged infringement of an automotive technology patent. The Supreme Court emphasised careful claim interpretation at the interim stage.

The Court highlighted that patents must be examined strictly on the basis of claims. It reinforced structured analysis in granting or refusing interim injunctions.

The case is frequently cited in matters involving interim relief.

Ravi Kamal Bali v. Kala Tech (2008)

This case involved a patented tamper lock/seal. The defendant manufactured a product with similar functional characteristics. The court applied the doctrine of equivalents.

It restrained the defendant from producing the substantially similar product. The judgement illustrates how minor changes cannot defeat patent protection if the essential function remains identical.

Conclusion

Patent infringement represents unauthorised interference with statutory monopoly rights granted under the Patents Act, 1970. The law provides a comprehensive enforcement framework covering direct and indirect infringement, evidentiary rules, recognised doctrines and structured remedies.

The remedies of injunction, damages and destruction of infringing goods are designed to preserve the value of innovation and ensure fair competition. At the same time, defences such as invalidity, experimental use and exhaustion balance private rights with public interest.

Note: This article was originally written by  Tanishka Ruia (PES University) on 22 May 2021. It was subsequently updated by the LawBhoomi team on 22 February 2026.