Essential Guide to Defending Against Patent Infringement

Table Of Contents

What Are Defences Against Patent Infringement?

Defences against patent infringement are legal arguments used by an alleged infringer to avoid liability. A common defence involves challenging the validity of the patent itself. The alleged infringer argues the patent should never have been granted by the patent office. The alleged infringer presents evidence showing the claimed invention lacks novelty or was obvious at the time of filing.
Another defence involves proving the accused product or process does not actually infringe the patent claims. The alleged infringer demonstrates the accused product or process lacks one or more elements of the patent claim. The alleged infringer may also argue the patent owner has no standing to sue for infringement. The alleged infringer may show the patent owner lost ownership of the patent.

How Does Non-Infringement Defend Against Patent Infringement?

Non-infringement defends against patent infringement by showing the accused product or service falls outside the scope of the patent claims. This defence is a primary legal strategy for many defendants. The alleged infringer performs a detailed claim construction analysis. The alleged infringer then compares the construed claims to the accused product or service.
The defence of non-infringement requires a precise understanding of the patent’s language. The alleged infringer must demonstrate that at least one element of the patent claim is missing from the accused product or process. The alleged infringer may also argue the accused product operates under a different principle than the patented invention. The alleged infringer presents expert testimony to support the non-infringement argument.

When Does Patent Invalidity Defend Against Patent Infringement?

Patent invalidity defends against patent infringement when the defendant proves the patent should not have been issued. The patent invalidity defence challenges the fundamental legality of the patent. The alleged infringer typically argues the patent fails to meet statutory requirements for patentability. The alleged infringer may claim the invention was not novel or was obvious.
The alleged infringer provides compelling prior art evidence to invalidate the patent. Prior art includes earlier patents, publications, or public uses that disclose the invention. The alleged infringer demonstrates the patent claims are anticipated by the prior art. The alleged infringer also shows the claims are rendered obvious by combining multiple prior art references.

What is Prior Art's Role in Defending Against Patent Infringement?

Prior art plays a important role in defending against patent infringement by demonstrating the patent’s invalidity. Prior art consists of all information publicly available before the patent's filing date. This information can include existing patents, scientific papers, product catalogues, and public demonstrations. The alleged infringer searches extensively for relevant prior art.
The alleged infringer uses prior art to show the patented invention was not new or was obvious. If the invention was already known or obvious to a person skilled in the art, the patent is invalid. The alleged infringer presents a detailed comparison of the prior art with the patent claims. The alleged infringer persuades the court the patent should be cancelled.

How Does Licence Defend Against Patent Infringement?

A licence defends against patent infringement when the alleged infringer has permission from the patent owner to use the patented invention. A patent licence is a legal agreement between the patent owner and another party. The licence grants the other party specific rights to make, use, or sell the patented invention. The alleged infringer presents the valid licence agreement as proof of authorisation.
The terms of the licence agreement dictate the scope of the permitted use. The alleged infringer must make sure the accused activities fall within the licence’s boundaries. Any use outside the licence terms constitutes infringement. The alleged infringer demonstrates compliance with all licence conditions, including royalty payments and territorial restrictions.

What is Patent Exhaustion's Role in Defending Against Patent Infringement?

Patent exhaustion's role in defending against patent infringement is limiting the patent owner’s rights after the first authorised sale. Patent exhaustion occurs when a patent owner sells a patented article. The sale transfers ownership of the specific article to the buyer. The buyer uses, sells, or modifies that article without further patent infringement liability.
The patent owner’s rights to control the article are exhausted after the initial sale. This defence prevents the patent owner from asserting patent rights against subsequent purchasers of the same item. The alleged infringer proves the accused product was legitimately purchased from the patent owner or an authorised licensee. The alleged infringer demonstrates the first sale was unconditional.

FAQS

How does a defence of laches protect against patent infringement?

A defence of laches protects against patent infringement when the patent owner delays unreasonably in filing a lawsuit. The unreasonable delay prejudices the alleged infringer. The alleged infringer must prove the patent owner knew of the infringement but waited too long to act.

What is the innocent infringement defence against patent infringement?

The innocent infringement defence against patent infringement applies when the alleged infringer had no knowledge of the patent. This defence may limit damages but rarely completely avoids liability. The alleged infringer must prove a lack of actual notice of the patent.

Can prior use be a defence against patent infringement?

Prior use can be a defence against patent infringement under specific circumstances. The alleged infringer must have used the invention commercially before the patent's effective filing date. The alleged infringer demonstrates continuous prior commercial use.

How does equitable estoppel defend against patent infringement?

Equitable estoppel defends against patent infringement when the patent owner misled the alleged infringer. The alleged infringer relies on the misleading conduct. The alleged infringer then suffers prejudice from the patent owner’s later assertion of rights.

What is the experimental use defence against patent infringement?

The experimental use defence against patent infringement is a legal argument. An alleged infringer uses the defence. The alleged infringer proves the use was not for commercial gain. This defence is narrow.

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