Exploring the Different Facets of Patent Infringement

When someone invents a new product or process and secures a patent for it, the law grants them exclusive rights to control how that invention is made, used, sold, or imported. But patent protection is only as strong as its enforcement – and infringement, the unauthorized use of a patented invention, can take many different forms. Under the Indian Patents Act, 1970, while the statute does not explicitly define “patent infringement,” it is clear from Section 48 that any unauthorized act of making, using, offering for sale, selling, or importing a patented product or process constitutes a violation of the patent holder’s exclusive rights. Understanding the different types of infringement is essential – both for inventors protecting their work and for businesses navigating the competitive landscape of innovation.

The broad classification: direct and indirect infringement 🔗

At the highest level, patent infringement in India is classified into two broad categories: direct infringement and indirect infringement. Everything else – deliberate copying, minor modifications, contributory acts, or innocent mistakes – falls within or alongside these two categories. Let’s break each one down.

Deliberate (wilful) infringement 🔗

Deliberate or wilful infringement is the most straightforward and the most serious type. It occurs when a person or entity is fully aware of an existing patent and still proceeds to make, use, sell, or import the patented invention without authorization. There is no ambiguity here – the infringer knows the patent exists and chooses to disregard it.

Consider a company that, after reviewing a competitor’s publicly available patent documentation, manufactures and sells a functionally identical product without obtaining a licence. Indian courts have recognized wilful infringement as particularly damaging, and it is treated as an aggravated form of violation. The burden is on the patent holder to prove that the infringer had knowledge of the patent, which is often demonstrated through prior communications, cease and desist letters, or internal records discovered during proceedings.

Why wilful infringement carries heavier consequences 🔗

While the Indian Patents Act, 1970 provides remedies such as injunctions, damages, and accounts of profits under Section 108, wilful infringement can significantly influence how courts assess quantum of damages. Courts take a dim view of intentional violations, particularly when a company had actual notice of the patent and still proceeded to exploit the invention commercially.

Deliberate infringement with minor modifications 🔗

A particularly crafty form of infringement involves making minor, insubstantial changes to a patented invention and then claiming that the resulting product is different enough to be non-infringing. This is where the doctrine of equivalents becomes critical.

Under the doctrine of equivalents, a product or process that does not literally infringe upon the express terms of a patent claim may still be found infringing if there is “equivalence” between the elements of the accused product and the patented invention. The test applied is whether the accused invention performs substantially the same function, in substantially the same way, to achieve substantially the same result as the patented claim.

So if a competitor slightly alters the chemical composition of a patented compound but achieves the same therapeutic effect through essentially the same mechanism, courts can still find infringement. Indian courts apply the doctrine of equivalents to prevent infringers from using “colourable” methods – making trivial, insubstantial variations specifically designed to sidestep patent claims while capturing all the commercial benefit of the original invention.

It is important to note that this doctrine has limits. It cannot be used to cover prior art or to recapture subject matter that was surrendered during the prosecution of the patent application – a principle known as prosecution history estoppel.

Indirect infringement 🔗

Indirect infringement is more nuanced – it involves someone who may not themselves be making or selling the patented product but who plays a role in enabling someone else to infringe. Indian patent law recognizes two forms of indirect infringement: induced infringement and contributory infringement.

Induced infringement 🔗

Induced infringement occurs when one party actively encourages, instructs, or assists another party to commit direct infringement. The key element is intent – the inducer must have known about the patent and deliberately encouraged the infringing activity.

A practical example: a software company that provides detailed technical guides on how to configure its product in a manner that infringes a competitor’s patented process could be held liable for induced infringement, even if the company itself is not the one running the patented process. To establish induced infringement, the patent holder must demonstrate that the inducer had knowledge of the patent, intended to cause the direct infringement, and that actual direct infringement by a third party did occur.

Contributory infringement 🔗

Contributory infringement sits at the intersection of indirect and secondary liability. It occurs when a person supplies a component or material that has no substantial commercial use other than as a part of a patented invention, knowing that it will be used in an infringing product.

Here is a useful illustration: suppose A holds a patent on a specialized water purification device. B manufactures a device substantially similar to A’s. C knowingly supplies a specific filtration component – one that has no practical use outside of B’s infringing device – to B, enabling B’s infringement. In this scenario, B is the direct infringer, and C is a contributory infringer because C knowingly supplied the critical component that made the infringement possible.

The Indian Patents Act does not explicitly codify contributory infringement, but Indian courts have recognized and applied this concept through judicial interpretation, drawing from principles of tort law and international patent practice. The crucial point is that a generic, multi-use component will not attract contributory infringement liability – the supplied item must be specifically suited for use in the infringing product with no meaningful alternative use.

Accidental infringement 🔗

Accidental infringement is perhaps the most legally counterintuitive type. It occurs when an inventor independently develops an invention that is substantially identical to an already-patented one – without any knowledge of the existing patent. This is not plagiarism. It is simply two inventors arriving at the same solution, which is not uncommon in fields where researchers worldwide are working on similar technical problems.

The critical legal point here is this: independent creation is not a defence to patent infringement. Unlike copyright law, where independent creation is an absolute defence, patent law operates on a strict liability basis. Once a patent is granted in India, it becomes part of the public record through the Indian Patent Office. Inventors are legally expected to conduct thorough prior art searches before commercializing an invention. The failure to do so – even if innocent – does not provide immunity from infringement claims.

This places a significant practical burden on innovators. A startup developing a new drug delivery mechanism, for instance, must conduct rigorous patent searches globally before launching its product, because coincidental overlap with an existing patent can result in full infringement liability despite zero intent to copy.

The independent invention defence: why it doesn’t work in patent law 🔗

The rationale behind rejecting independent invention as a defence comes from the very nature of patents. A patent is a public bargain – the inventor discloses the invention to the world in exchange for a time-limited monopoly. The disclosure is published, searchable, and accessible. Courts reason that any person commercializing a new technology has a responsibility to examine existing patents, and the fact that they independently arrived at the same invention does not override the patent holder’s exclusive rights. Section 48 of the Patents Act grants rights unconditionally to the patent holder against all unauthorized use, regardless of the mental state of the infringer.

Innocent infringement 🔗

Innocent infringement refers to a situation where the infringer had no actual knowledge of the patent at the time of infringement. While this does not eliminate liability – for the same reasons that make independent invention irrelevant as a defence – it can influence the relief that courts grant, particularly regarding damages.

Under Indian patent law, if a patent holder has not marked their product with the patent number, it can affect their ability to claim full damages for infringement during the period before the infringer became aware of the patent. This is why patent marking – affixing the patent number to the product or its packaging – serves an important legal function. It provides constructive public notice, making it harder for an alleged infringer to claim genuine ignorance of the patent’s existence.

In practical terms, an innocent infringer who promptly ceases infringing activity upon being notified of the patent, and cooperates in resolving the matter, may face more limited consequences compared to a wilful infringer who persists despite notice. However, courts will still typically grant injunctive relief to stop the ongoing infringement, even in innocent cases.

How infringement type affects legal consequences 🔗

The type of infringement established in court directly shapes the remedies available to the patent holder. Under Section 108 of the Patents Act, 1970, the key remedies are injunctions (temporary or permanent orders to stop the infringing activity), damages (financial compensation for losses suffered), and accounts of profits (requiring the infringer to surrender profits earned from the infringement). Wilful infringement can attract the full range of these remedies and may result in significantly higher damages. Innocent or accidental infringement may result in limited damages, especially for the period before the infringer had notice of the patent. Contributory or induced infringement may lead to injunctions specifically crafted to stop the supporting activity, in addition to damages.

It is also worth noting that under Section 104A, in suits involving process patents, the burden of proof can be shifted to the defendant – a TRIPS-driven amendment that strengthens enforcement for process inventions, which are otherwise harder to detect and prove.

Practical takeaways for innovators and businesses 🔗

Understanding these categories of infringement is not just academic – it has direct commercial implications. For patent holders, clear patent marking, active market monitoring, and timely cease and desist notices are critical tools for protecting rights and maximizing remedies in any future litigation. For product developers and businesses, conducting a thorough Freedom to Operate (FTO) analysis before launching any product is essential. An FTO search assesses whether a product or process would infringe any valid, in-force patents in the relevant markets. This step can mean the difference between a clean commercial launch and an expensive infringement dispute – even when there was never any intention to copy someone else’s invention.

What do you think? In a world where multiple researchers and companies often work on the same technical problem simultaneously, is strict liability for accidental patent infringement a fair standard – or does it create an unreasonable burden for independent innovators? And given how complex patent claims can be, how realistic is it for small startups to conduct truly comprehensive prior art searches before bringing a product to market?

References

1. https://blog.ipleaders.in/concept-patent-infringement/
2. https://ssrana.in/ip-laws/patents/patent-infringement-india/
3. https://www.indiacode.nic.in/bitstream/123456789/1392/1/A1970-39.pdf
4. https://www.mondaq.com/india/patent/1397300/the-doctrine-of-equivalents-in-patent-law-an-overview-of-the-law-in-india
5. https://www.legalservicesindia.com/article/2532/Infringement-of-Patents.html
6. https://www.mondaq.com/india/patent/949758/patent-infringements-and-their-types
7. https://taxguru.in/corporate-law/patent-infringement-india.html
8. https://razorpay.com/learn/patent-infringement/
9. https://blog.ipleaders.in/an-overview-of-the-patent-infringements-and-remedies-available-in-india/