Patent Infringement — Legal Remedies and Defences Under Indian Patent Law

Direct Infringement: When someone directly makes, uses, sells, or imports the patented invention without authorization. This is the most common type of infringement and requires literal or equivalent use of the patented invention.

Indirect Infringement: Includes contributory infringement (supplying essential components of a patented invention knowing they will be used for infringement) and inducing infringement (actively encouraging another to infringe). Under Indian law, joint tortfeasorship principles apply.

Infringement is determined by comparing the allegedly infringing product or process with the patent claims. Claim construction is the first step — the court interprets the meaning and scope of the patent claims based on the specification and prosecution history.

The two primary tests are: (1) Literal Infringement — every element of the claim is present in the accused product, and (2) Doctrine of Equivalents — the accused product performs substantially the same function in substantially the same way to achieve substantially the same result.

Injunction: The primary remedy. Interim injunctions are granted if the patentee demonstrates a prima facie case, irreparable harm, and balance of convenience. Perpetual injunctions are granted after trial.

Damages: The patentee can claim actual damages suffered or elect for an account of the infringer's profits. Damages are calculated based on lost profits or reasonable royalty.

Delivery up and Destruction: The court can order infringing products to be delivered and destroyed.

Declaration of Infringement: A court declaration that the patent has been infringed, which can be used for publicity and deterrence.

Under Section 106 of the Patents Act, if a person makes groundless threats of infringement proceedings against another, the aggrieved person can file a suit for relief including a declaration that the threats are unjustifiable, an injunction against further threats, and damages.

This provision prevents patentees from making frivolous threats to intimidate competitors or customers. A prudent patentee should conduct thorough infringement analysis before issuing threats.

Non-Infringement: The accused product does not fall within the scope of the patent claims as properly construed. Invalidity of Patent: The patent is invalid on grounds of lack of novelty, inventive step, or insufficient disclosure.

Experimental Use: Use of the patented invention for experimentation or research is not infringement. Prior Use: A person who was using the invention before the priority date can continue using it.

Government Use: The government or its authorized agents can use the patented invention for its own purposes without infringement. Compulsory License: If a compulsory license has been granted, use by the licensee is not infringement.

Before filing suit, conduct a thorough infringement analysis and validity assessment. Consider sending a cease and desist notice to explore settlement. If urgent relief is needed, file for an interim injunction.

Patent litigation in India is heard in the High Courts (original jurisdiction or IP Division). Evidence is submitted through affidavits, and cross-examination is permitted. Technical experts are often appointed to assist the court.

The limitation period for filing a patent infringement suit is 3 years from the date of infringement. Continuing infringement gives rise to a fresh cause of action each day.