This article has been written by Neha Gandhi pursuing Diploma in Law Firm Practice: Research, Drafting, bRiefing and Client Management and edited by Oishika Banerji (Team Lawsikho). 

It has been published by Rachit Garg.


Patent is a type of intellectual property granted by the patent authority to the inventor for a limited period of time for exercising monopoly over his specific innovation. A patent is considered to be an exclusive monopoly right as it excludes others from using, selling, distributing the invention of innovators. Patent Infringement is illegal as it violates the exclusive right of the patent holder. It is crucial for individuals and companies to be aware of patent laws and the consequences of patent infringement. It is important to take steps to protect one’s own patents, as well as to avoid infringement of the same by others. With technology rapidly advancing, it has become increasingly important to understand the complexities of patent infringement and how it affects innovation and progress. This article aims to reflect the same. 

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Types of patent infringement 

Classification of patent infringement have been discussed hereunder. 

Direct infringement

Direct infringement is a most common and obvious form of patent infringement. When a third party without the permission of the patent holder: 

  • Commercially uses the invention. 
  • Reproduces the invention.
  • Import a protected idea/ invention in India.
  • Selling patented inventions.
  • Offer to sell patented inventions.

Direct infringement can either be intentional or unintentional during the term of patent. Only requirement to be fulfilled is the performance of a substantially deceptive function of an invented product without obtaining a legal licence from the owner for the usage. For example, Samsung started using the same manufacturing process as the Apple company for making phones, without taking permission. This is a direct infringement of a patent existing on the product, owned by the Apple company. 

Literal infringement

Literal infringement is a type of direct infringement in which each and every element or composition protected by either product or process patent is copied, in other words, a replica of the original product is used, manufactured, sold or imported.

In the case of Polaroid Corp. vs. Eastman Kodak Co (1986), Polaroid claimed that Kodak had violated its patent right related to instant photography. The central dispute revolved around Kodak’s instant photography system, which Polaroid argued had utilised its patented technology. Polaroid believed that four of its patents related to instant photography, including the process of developing an instant image and the instant camera itself, were infringed by Kodak. After a prolonged trial, the court ruled in favour of Polaroid, determining that Kodak had indeed infringed upon Polaroid’s patents. As a result, Kodak was ordered to stop the production and sale of its instant photography system and Polaroid was awarded substantial damages.

Non-literal infringement

Non-literal infringement is also recognised by the name of Doctrine of Equivalence. In this type of infringement, the alleged invention has to pass through the “Triple Identity Test”. This means when an invention is similar to the patented invention hence performing significantly the same function, in the same way and producing the same result, may even differentiate in name, shape or form, that invention will be said to have caused non-literal infringement of the previously patented invention. 

In the landmark case of Ravi Kamal Bali vs. Kala Tech. & Ors (2008), the plaintiff was granted patent for ‘tamper lock/seals’ and the defendant constructed a similar kind of product by the name of ‘Seal Tech’, which had the similar functional features as the plaintiff’s lock. The court of law had applied the Doctrine of Equivalence, and gave the decision in favour of the plaintiff stating that both the products had exactly the same function and also was made up from the same material with the only slight differentiation was of construction which did not constitute an innovation.

Indirect infringement

Indirect infringement occurs when a third party supports, contributes or promotes the direct infringement. The infringement can either be accidentally or knowingly. 

Induced infringement

Induced infringement involves wilful aiding of the infringing process, with or without any intention to infringe. In either case, the infringer shall be held liable for infringement. The aiding can be in the form of:

  • Assisting in manufacturing of the product.
  • Assembling the patented product without proper licence.
  • Providing instructions to third parties on production of product.
  • Printing the instructions of patented items and selling them.
  • Licensing plans or processes.

Contributory infringement

Contributory infringement is a kind of indirect infringement in which the infringer sells or supplies the parts of a product used exclusively to manufacture the patented products. The infringer is held liable even if he doesn’t actively participate in the manufacturing process.

Wilful infringement

Wilful infringement occurs when someone disregards the patent invention voluntarily. The burden of proof in this case lies on the patent holder. The infringer can take the defence of legal opinion thoroughly in writing. Three step process for willful infringement are:

  • Knowledge about the patented invention,
  • Good faith belief that the infringer wouldn’t be liable for patented invention,
  • Infringer’s belief is reasonable. 

If the wilful infringement is proved, the court can order strong deterrents (3 to 4 times of actual damage), inclusive of court costs, lawyer’s fees etc. 

Burden of proof 

The burden of proof in patent infringement originally lies upon the patentee (the plaintiff). However, TRIPS amended the Patents Act, 1970 by insertion of Section 104A thereby introducing the concept of “reversed burden of proof”. This signifies that if the subject matter of patent is a process and results to;

  1. A new product, and
  2. There is substantial likelihood that an identical product is made by the same process and the patentee, despite reasonable efforts, failed to determine the process.

Then the burden of proof is on the defendant to prove the non-infringement.

Doctrines related to patent infringement

Doctrine of equivalents

Doctrine of equivalents is a legal rule that is applied to find out the patent infringement. The doctrine classifies even a minor change to the product as an infringement. In simple words, if the infringed product performs significantly the same function, in the same way and produces the same result, then it shall lead to patent Infringement under the doctrine of equivalents. 

Limitations to the doctrine of equivalents

  1. All elements rule: All the elements of a patented product should be present in the infringed product.
  2. Doctrine of public dedication: This doctrine is applicable when a patentee discloses publically the subject matter of patent but does not claim it. Anyone can then use it without fear of infringement.
  3. Existence of prior art: Invention already publicly available and known, before filing of the patent application signifies existence of prior art. In other words, the invention is not unique or exists already in some form.
  4. Prosecution of history estoppel: Also known as File-Wrapper Estoppel, it arises as a legal defence to infringement. It applies where a patent application amends or cancels a claim rejected by the Patent Office as unpatentable based upon prior art.

In the landmark case of Graver Tank vs. Linde Air (1950), the disputed patented formulation was a mixture of alkaline earth metal silicate (using magnesium) and calcium. The accused used manganese, and silicate but not any alkaline earth metal. Experts stated that manganese served the purpose of magnesium and was equivalent to it. In this case, the court had opined that “a person reasonably skilled in his work would have known of the replaceable element“. Interchanging of magnesium with manganese was obvious to anyone working in the same field and was an insubstantial change. Therefore the court upheld the finding of patent infringement under the doctrine of equivalents.

Doctrine of colourable variation

The doctrine is derived from a latin maxim, “Quando aliquid prohibetur ex directo, prohibetur et per obliquum” which means “what cannot be done directly, should also not be done indirectly”. According to this doctrine, the practice of making minor changes to a patented invention in order to invade the patent infringement claims,  is substantially considered to be the same as the patented invention, even though it may have some apparent differences. This means that an infringer cannot neglect liability by making minute changes to the patented invention. Some of the factors considered by court in order to decide whether a variation is colorable or not are provided hereunder:

  1. The extent of resemblance between the alleged invention and the accused product or process.
  2. The degree of distinction between the two products or processes.
  3. The aim or intended usage of the accused product or process.
  4. The competency level of the relevant industry at the time the patent was in use.
  5. The level of difficulty involved in creating the accused product or process
  6. The level of certainty in the relevant industry.
  7. The degree of self-creation or prior knowledge.
  8. Proof of Copying or other methods of direct violation of patent infringement.

The case of Pfizer Inc. vs. Cadila Healthcare Ltd (2020), involves a dispute over the patent for the anti-inflammatory drug Celecoxib. Pfizer alleged that Cadila’s generic version of the drug infringed Pfizer’s patent, but Cadila argued that its product was different from Pfizer’s product and therefore did not infringe the patent. The Supreme Court of India found that Cadila’s product was a colorable variation of Pfizer’s product, and amounted to infringement. 

What acts do not amount to patent infringement

There are several acts that does not amount to infringement-

  1. Independent invention: The impugned product or process was independently developed by the accused party, without any reference to or use of the claimed invention of the patent. To prove independent invention, the accused party typically needs to provide evidence of their invention, such as records of their development activities, laboratory notebooks, or testimony from witnesses. This evidence should demonstrate that the accused party was working on the same problem as the patent holder and arrived at the same solution independently and without reference to the claimed invention of the patent.
  2. Patent expiration: When a patent expires, the inventor’s exclusive rights to the invention are no longer in effect and anyone may use the invention without infringing the patent.The term of a patent is typically set by law and is typically 20 years from the filing date of the patent application. After the patent has expired, the claimed invention becomes part of the public domain and can be freely used by anyone without fear of infringing the patent.To prove that the patent has expired, the accused party can typically provide evidence of the filing date of the patent and the relevant patent law to demonstrate that the patent has reached the end of its term.
  3. Research and experimentation: Experimental use of a patented invention for the purpose of testing or evaluating it is not considered infringement. In other words, the accused party is claiming that they were using the claimed invention to test and evaluate its performance, and that they did not intend to sell or otherwise commercially exploit the invention.
  4. Government use: In many countries, the government has the right to use a patented invention without infringing the patent for the purpose of fulfilling its responsibilities and providing services to the public. The accused product or process is used by or on behalf of the government and is therefore not subject to the patent. This defence is based on the idea that the government should have the right to use patented inventions for various public purposes, such as for national security or for the provision of essential services, without being subject to infringement claims.
  5. Prior use: If a person has been using a patented invention before the patent was granted, they may be able to continue using it without infringing the patent, depending on the laws of the relevant jurisdiction. To prove prior use, the accused party typically needs to provide evidence of their use of the accused product or process before the filing date of the patent.
  6. Fair use:  The concept of fair use allows for limited use of a patented invention for purposes such as criticism, commentary, news reporting, teaching, scholarship, or research. The defence is based on the idea that certain uses of a patented invention should be allowed without infringing the patent, even if they would otherwise be considered infringing, in order to promote the public good and encourage creative and intellectual activity. To prove fair use, the accused party typically needs to show that their use of the patented invention was for a permissible purpose under copyright law and that it was reasonable in scope and impact. 
  7. First sale doctrine: The first sale doctrine, also known as the exhaustion doctrine, provides that the sale of a patented item by the patent holder or with their authorization exhausts their patent rights and allows the buyer to use or resell the item without infringing the patent. The doctrine is based on the idea that the patent holder’s exclusive rights to the patented invention are limited and that the rights of others to use, sell, or distribute a patented product should not be unduly restricted. The first sale doctrine is often invoked in cases involving the resale of patented products, such as used books, CDs, or other products that were legally obtained through a sale or transfer. By applying the first sale doctrine, these products can be resold or otherwise distributed without infringing the patent, provided that the product was not altered or modified in a way that would give rise to a new patent infringement.
  8. Invalidity or unenforceability of the patent: If a patent is found to be invalid or unenforceable, any act that would have otherwise constituted infringement would not be considered infringing.

Defences available against patent infringement

  1. Estoppel: Estoppel is a legal principle that can be used as a defence against a claim of patent infringement. The principle of estoppel states that a person cannot assert a right that they have previously renounced or abandoned. In the context of patent infringement, estoppel can be used as a defence when the patent holder has made statements or taken actions that indicate that they do not believe the accused party is infringing their patent. For example, if the patent holder has licensed the accused party to use the patented invention or has allowed the accused party to use the patented invention for a significant period of time without asserting their patent rights, the patent holder may be stopped from later claiming that the accused party is infringing their patent.
  2. Licence: A licence is a legally binding agreement between the patent owner and another party, in which the patent owner grants the other party permission to use the patented invention in exchange for some form of compensation. In the context of a patent infringement claim, a licence defence argues that the accused product or process is being used under a licence or other agreement with the patent owner that permits the use. This means that the accused party has a right to use the patented invention, and therefore cannot be held liable for infringing the patent.
  3. Plaintiff is not entitled to sue: The plaintiff who is claiming patent infringement does not have the legal right to bring a lawsuit for the infringement. This defence can be raised for a variety of reasons, such as lack of standing, assignment of the patent, invalidity of the patent, statute of limitations, or a settlement or licensing agreement. For example, if the patent has been assigned to someone else, the original owner is no longer entitled to sue for infringement and the new owner must bring the lawsuit instead. Similarly, if the patent is found to be invalid, the plaintiff is not entitled to sue for infringement as they do not have a valid patent to enforce. 

Remedies for patent infringement

Section 108 of Patent Act,1970 deals with the “Reliefs in suit for infringement”. The remedies for a suit filed in the infringement of a patent can be classified into three types, they are:

  1. Injunction: In the context of patent infringement, an injunction is a court order that requires the infringing party to stop making, using, selling, or importing the infringing product. It is a preventative measure that aims to preserve the value of the patent and prevent further harm to the patent holder. To obtain an injunction, the patent holder must prove that their patent is valid and that it has been infringed upon by the defendant. Injunction is of three kinds:
  • Temporary Injunction: It is a kind of temporary remedy that is provided before the final verdict of the case. It is used to preserve the status quo of the patent holder. Moreover, they are likely to succeed in their lawsuit and will suffer irreparable harm if the infringing activity is allowed to continue. The court should consider three factors before granting temporary injunction to the patent holder- 

I. Prime facie case.

II. Balance of inconvenience.

III. Irreparable loss

  • Permanent injunction: It is a kind of permanent remedy that is granted when the case is finally decided by the court. It requires the infringing party to stop the infringing activity permanently. The court may also award monetary damages, such as compensation for any profits that the infringing party has made as a result of the infringing activity. To obtain a permanent injunction, the patent holder must file a lawsuit and prove that their patent is valid and that it has been infringed upon by the defendant. However, obtaining a permanent injunction can be a complex and time-consuming process, and the patent holder must have strong evidence to support their claim.
  • Ex-parte injunction: An ex-parte injunction is a provisional remedy that is used in urgent situations and is granted without a hearing. It is a powerful remedy for patent infringement, but it must be used with caution, as it may result in harm to the defendant if it is later found to be unjustified. It is typically used in urgent situations where the plaintiff needs immediate relief and there is not enough time for a full hearing.
  1. Damages: Damages is a remedy for patent infringement that compensates the patent holder for any harm that they have suffered as a result of the infringing activity. Damages may be awarded in the form of monetary compensation, such as compensation for any lost profits or other financial losses that the patent holder has suffered. The main objective of damages is to compensate for the loss or injury that happened to the plaintiff.
  2. Seizure, forfeiture or destruction: Courts may decree that the items determined to be infringing should be taken into custody, forfeited, or disposed of as deemed appropriate.

Landmark judgments 

1. Novartis AG vs. Union of India (2013)

The highly significant legal dispute in India concerning the principle of patent infringement. Swiss pharmaceutical company Novartis AG brought the case to the Supreme Court of India after its application for a patent for its anti-cancer drug “Glivec” was denied by the Indian Patent Office. The central issue of the case was the concept of “evergreening”, where companies try to prolong the life of their patents by making minor modifications to their products. Novartis claimed that its product was a new invention and thus deserving of patent protection. However, the Patent Office rejected the patent, stating that it was just a modification of an existing drug and not a new invention. 

The Supreme Court eventually ruled against Novartis, determining that its product was not a novel invention and therefore did not qualify for a patent. This ruling was seen as a positive outcome for public health and access to medicine as it prevented the evergreening of patents and ensured that generic versions of the drug would be available at more affordable prices.

2. Pfizer Inc vs. Dr. Reddy’s Laboratories Ltd. (2004)

Pfizer, a pharmaceutical company, sued Dr. Reddy’s Laboratories, a fellow pharmaceutical company in India, for violating their patent on the anti-inflammatory drug “Celebrex”. The central issue in the case was the interpretation of the Indian Patent Act’s provisions on compulsory licensing of patented drugs. Dr. Reddy’s Laboratories sought a compulsory licence to manufacture a generic version of the drug, claiming that it was necessary to ensure access to affordable medicines for the Indian population.

The Delhi High Court ultimately ruled in favour of Dr. Reddy’s Laboratories and granted the compulsory licence, allowing the company to produce a generic version of the drug. This ruling was considered a significant victory for public health and access to medicine in India, as it established key legal principles related to compulsory licensing of patented drugs.

3. Ericsson vs. Intex Technologies (2014)

The case is related to patent infringement in the mobile technology industry. The case was brought before the Delhi High Court by Swedish telecommunications company Ericsson, against Indian consumer electronics company Intex Technologies, for infringement of Ericsson’s standard-essential patents (SEPs) related to mobile technology.

SEPs are patents that are considered essential for the implementation of a technical standard and are required for the manufacture of certain products. The issue at the heart of the case was the principle of fair, reasonable and non-discriminatory (FRAND) licensing for SEPs. Ericsson claimed that Intex had used its SEPs without obtaining a licence from Ericsson and that the licence fees demanded by Ericsson were fair and reasonable.

The Delhi High Court ruled in favour of Ericsson and ordered Intex to stop using Ericsson’s SEPs and to pay a reasonable royalty to Ericsson. The court also ruled that SEP holders have an obligation to licence their patents on FRAND terms and that licensees have the right to seek a judicial determination of the terms of a FRAND licence.

4. BAJAJ Auto Limited vs. TVS Motor Company Limited JT (2009)

The Supreme Court of India held that TVS had infringed BAJAJ’s patent, as the design of the three-wheeler produced by TVS was found to be substantially similar to that of BAJAJ. The court held that the patent granted to BAJAJ was for a new and useful invention and that the design of the three-wheeler produced by TVS was a reproduction of the patented design.

In its decision, the court emphasised the importance of treating patients as a form of property, with infringement being a violation of the patent holder’s rights. The decision in this case highlighted the need for companies to respect the patents of others in order to maintain a fair and competitive business environment. Overall, the case reinforced the importance of protecting patents and intellectual property rights in India.


In conclusion, patent infringement refers to the unauthorised use or manufacture of a patented invention without the consent of the patent owner. The Indian Patent Act, 1970 provides several remedies to address patent infringement, including injunctions, damages, and seizure, forfeiture or destruction. However, the enforcement of these remedies remains a challenge due to the complexity of the Indian legal system and the length of time it takes to resolve a patent dispute. To protect their patented inventions, businesses in India must be proactive in monitoring for infringement and pursuing appropriate legal action when necessary. Additionally, it is important for businesses to have a thorough understanding of the Indian patent law and the remedies available to them in case of infringement. This will help ensure that their intellectual property rights are adequately protected and that they receive fair compensation for any unauthorised use of their patented inventions. It is crucial for businesses to conduct proper due diligence and research before filing for a patent to ensure that their invention is novel and non-obvious. This will help to minimise the risk of infringement and ensure that the patent is enforceable. 


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