What is a Patent Infringement?

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What is Patent Infringement? 

Define Infringer (An unauthorized act) Patent Infringement happens when any product or technology reads on the entire claim limitations of the patent. When any product or technology is sold, manufactured, or is in use without the consent or knowledge of that patent owner, he/she has the right to file a lawsuit against the concerned person or the company. It provides the patent owner with the exclusive rights to their invention so that they can provide a license for the production and selling of the patented products. 

How to Detect Patent Infringement? 

To detect whether a patent is infringed or not is usually an infringement search. In this, an infringement search is conducted on the behalf of the patent holder to find out if there are products or technologies in the market that could be using the patent owner’s invention.  

All the product disclosures, videos, manuals, datasheets, etc. are analyzed to find out whether the product or technology found after the earliest priority date of our patent invention discloses each element of the granted claim.  

However, there are a few exceptions like the Doctrine of Equivalents that permits infringement even though not every claim element has been disclosed in the infringing product.  The doctrine of Equivalents aims to prohibit an infringer party from using the patented invention by changing only small details of the claimed invention while having the same functionality. Equivalency is determined when the infringing product or technology contains elements identical or equivalent to each claimed element of the granted patent invention. 

In some cases, special expertise like reverse engineering, product teardown, etc is required to confirm a specific claim element of the granted claim. 

If overlapping is found between the product literature and patented invention, then a detailed claim chart is produced in which a feature-wise mapping of the product is performed in accordance with the claimed elements. 

What is Patent Protection? 

Patents are territorial rights granted in a country or a region. The scope of patent protection differs from country to country. The infringement of a patent is valid in the country in which it is in effect. For example, when a patent is granted in one country, then anyone in that country is not allowed to make use of the invention disclosed in the granted patent.  

However, anyone outside that country may be allowed to use the granted patent invention. Also, Patent protection is granted for a limited time only, generally 20 years from the application filing date. 

Process to Conduct Infringement Search: 

  1. Understanding of the subject patent 
  2. Understanding of patent file-wrapper and identifying novelty statement 
  3. Analysis of forward citations (102, 103 examiner rejections)  
  4. Relevant keywords and Concepts Extraction 
  5. Broad analysis of target company 
  6. Use of XLSCOUT EoU tool and internal datasets for first pass analysis. The information from the first pass analysis may comprise relevant/potential leads/ relevant technology keywords / relevant video links. 
  7. Use of first pass data with other information from the above step to fasten and optimize the manual search to identify broad leads related to the subject patent technology. The broadly related leads may comprise webpages, PDF documents or videos of the target company or relevant technology standards 
  8. Use of webpage and image search tools, video caption search tools, large pdfs search tools, or technical standards search tools. 
  9. In-depth manual analysis of related webpages, PDFs, and videos of the product or standards to prepare EoU charts 
  10. The recommendation is made in EoU claim charts for reverse engineering including source code analysis of the products/technologies to make high-value claim charts 

Types of Patent Infringement 

If you have a granted patent over your Invention, and someone is using your registered invention without your consent, then that person is infringing your patent rights. So, various types of patent infringement occur, when another entity makes, uses, or sells a registered invention in a country, which is already patented, without the permission of the inventor/owner. For a patent infringement, understanding the various types of patent infringement helps to determine who is at fault. 

Different Types of Patent Infringement are given as Follows: 

  • Direct Infringement 
  • Indirect Infringement 
  • Contributory infringement 
  • Induced infringement 
  • Willful Infringement 
  • Literal Infringement 

What is Direct Infringement? 

Direct infringement is observed as the most common type of infringement. As it involves the production, sale, or commercial use of a patented idea or invention without obtaining the permission of the owner. 

In Direct infringement, the infringer need not have any knowledge of the patented invention. For example, In the United States under §271(a), just engaging in one of the five forbidden activities makes one accused of infringement.

The five acts which are proscribed, when performed without obtaining authorization from the patent’s owner, are given the following: 

  • Producing a patented idea/invention.
  • Using a patented idea/invention.
  • Offering a patented idea/invention for sale.
  • Selling a patented idea/invention.
  • Importing a patented idea/invention into the United States

What is Indirect Patent Infringement? 

Indirect infringement, as its name suggests, occurs when infringement does happen, but when some individual or entity provides support for the direct infringement to infringe on a patented invention to another individual or entity. In the case of indirect infringement, direct infringement must coexist. But, for that direct infringement, a third party actively contributes, encourages, or supports the infringing process. 

For example, if ‘B’ designs an umbrella that is exactly like ‘A’ patented umbrella design. ‘B’ sells its umbrella to ‘C’ in the U.S., which sells them for distribution. While ‘A’ can sue ‘B’ for direct infringement, and ‘A’ might sue ‘C’ for indirect infringement. 

Indirect infringement is another form of patent infringement and there are two types of indirect infringement given as follows: 

  • Contributory infringement  
  • Induced Infringement 

What is Contributory Infringement? 

It is a type of indirect infringement, where a person is liable for contributory infringement if he does not act that infringes the right of the patent owner but indirectly contributes to infringement and gets benefitted. It takes place when a person intentionally instigates another person to materially contribute to infringement. 

In Contributory infringement, the person who is liable for Contributory infringement does not involve actively in infringing activities. Contributory infringement focuses on third parties that contribute to the infringement of a patent and gives owners a different way to protect their patented process or product.

Contributory infringement of a patent happens when a third party sells or imports a part or component that has exclusive use in the patented item. Even if selling that part or component is legal, they are still responsible for contributory infringement.  

If a third party sells a generic item that is not used exclusively for a patented product or the item has some other substantial non-infringing use, then the seller cannot be held liable even if the end-user uses the item to infringe on a patent.  

Example of Contributory Infringement. 

  • Selling of components used exclusively to produce patented items. 
  • Selling non-infringing components with instructions on how to use them in an infringing manner 
  • Selling a 3-d printed item with the same specification as claimed in the patent. 

What is Induced Infringement? 

To “induce” means another to act or in common language, to cause a person to do something he would not otherwise have done. Induced infringement occurs when one actively induces the other person to infringe a patent by encouraging, directing, advising, or instructing on how to infringe.  

Inducement doesn’t cause liability to occur until a direct violation takes place. Inducers must have more than mere knowledge so that infringing actions could occur. 

Induced infringement works like “the crime of conspiracy” in which you don’t break the law yourself but help someone else to break the law. The court would still hold you responsible for the crime.

Examples of Infringement by Inducement 

Difference Between Induced Infringement and Contributory Infringement 

Induced infringement is different from contributory infringement. While both are the type of indirect infringement and require knowledge of a patent, there are still few differences between them.

In “Contributory infringement”, a party helps someone else by supplying components that will lead to infringement while in induced infringement, one helps by directing, advising, or instructing another party on how to infringe. 

For example, let’s say someone invents a product and patents it. The inventor then sells this patent to a major company. Now the product is available in the market and is sold in every store. Years later inventor says he still owns the patent and sell the patent to another company. Once the second company starts to sell the product, the first company can sue it for infringement, and it can sue the inventor for inducing infringement. 

What Is Willful Infringement? 

Willful infringement happens when someone completely disregards for patented invention. Simply put, it is an act of copying the claimed invention even after knowing that it is a patented invention. This is considered disobedience to the patent law. In this type of infringement, the defendant found guilty gets charged with higher penalties, attorney fees, and court costs. The court can award up to three times the actual damages incurred. 

How to Determine Willful Infringement? 

Three step process is used to determine willful infringement :

1. Did the defendant have knowledge about the patented invention?

The first criterion is evaluating the knowledge of the defendant about the patented invention. If the defendant did not know about the patented invention at the time of infringement, then there will be no willful infringement. Having no willful infringement does not mean that there is no infringement, the defendant can still be held liable for infringement. 

2. Did the defendant have a good-faith belief that they would not be held liable for infringement of the patent? 

Infringement is not considered willful If the defendant has a good faith belief that they are not copying the invention, the patent is invalid or not enforceable. Here the defendant relies on the written opinion of counsel to establish good-faith belief, to avoid the act of willful infringement. 

3. Was the infringer’s belief reasonable considering the totality of circumstances?  

As per the Federal Circuit, once the person gets notice of an inventor’s patent rights it’s become his or her responsibility to respect those rights. The defendant’s reliance on the opinion of counsel doesn’t guarantee that the infringement would not be considered willful. The opinion lacking sufficient factual data could be considered incompetent by the court. 

Penalty for Willful Infringement 

In Willful infringement, the court can award up to three times the actual damages incurred. The defendant will end up paying higher penalties, attorney fees, and court costs.  

How to avoid Willful Infringement? 

A well-written opinion from a patent counsel could help in avoiding the willful infringement.  The written opinion must be well written and thorough enough. The written opinion mentioning that the party does not infringe the patent or that the patent is invalid or unenforceable could be useful. Written opinions are more impactful as compared to oral opinions. Also, the written opinion should be obtained on time, soon after the initial notice of the patent is received. 

What is Literal Infringement?

Literal infringement, as evident from the name, occurs when the alleged infringing product/device or processhas each feature that is in the claims of the patent. So, Literal infringement occurs, when the exact copy of a patented invention is being used, distributed, or imported. An accused product/device or process falls squarely within the scope of patent claims.  

Although an infringer rarely makes and sells the exact copy same product as the patented one. Even though such cases do occur, sometimes the infringer is from another country. Most of the time, cases involving literal infringement escalate to the level of litigation, there is usually some potential defense to the infringement allegations.  

For example, the alleged infringing party may defend by claiming that they are the ones with the licensed rights to make or sell that product/device or that the original patent is someway invalid. 

Literal infringement of a patent can’t be proven if the accused product/device is absent from even a single element of the patent claim.  However, even if the accused product or process adds new features to its product or process that were not present in the patent claims, but has all the claimed elements even then, it will infringe on the patent. 

Example of Literal infringement :

In case of direct infringement, a comparison of the alleged infringing product/device or process features with the claims of the patent is to be made to know the amount of patent infringement. The case of Polaroid Corp v. Eastman Kodak Co. [1986] was a case of literal infringement, wherein Eastman Kodak directly used the “instant camera technology”, which was a literal copy of the said patented invention of Polaroid Corp. 

A valid patent brings the right to the patent owner to exclude others from selling, making, using, or distributing the patented invention. In the United States under35 U.S. Code § 271, to successfully prosecute for patent infringement, the patent owner must prove that the accused infringed on the patent owner’s right by selling, making, or using, the patented invention in the United States, or distributed into the United States the patented invention without authorization rights.   

The patent owner needs to show that the accused infringing product/device literally has every element/feature of the patent’s claim. For example, in  Larami Corp. v. Amron, 27 U.S.P.Q.2d 1280 (E.D. Pa. 1993), Amron, a toy water gun maker, asserted that Larami Corp., which produces “SUPER SOAKERS” water guns, had infringed on its patent.

However, Super Soaker did not have the claimed element “elongated housing having a chamber therein for a liquid,” because the Super Soaker had a separate and removable water tank, therefore, the Super Soaker was not found guilty to be infringing.  

Examples of Patent Infringement 

  • Nokia – Apple Patent Infringement Case: It’s a very popular patent infringement case between two of the world’s high-profile companies like Nokia and iPhone maker Apple that got settled in May 2017.  

Initially, Nokia accused and filed a lawsuit against Apple in more than 10 countries including Germany and the United States claiming that Apple was infringing dozens of patents owned by Nokia and its subsidiaries like NSN and Alcatel lucent. These patents were mainly related to software, video coding, chipsets, display, UI, antenna, etc.  

Nokia claimed that Apple products were infringing these patents since iPhone 3GS. After fighting for more than a year Apple decides to pay a big amount ($2 billion) as an upfront cash payment to Nokia as part of the settlement for a patent infringement case. Apple also agreed to pay regular royalties to Nokia in the future.  

  • Apple-Samsung Patent Infringement Case: This case is one of the most popular ‘smartphone patent wars’ in the smartphone industry. In 2011, Apple accused Samsung of infringing three Apple iPhone design patents and two utility patents in a US court.  

The world witnessed two smartphone industry giants fighting over the designs and software functionality features of their mobile phones and tablets. Apple stated that Samsung copied the designs and features pioneered by Apple in the iPhone and the iPad.  

The legal battle revolved around the basic smartphone features such as tap to zoom and the home screen app grid etc. After seven long years, the legal patent infringement fight between the two high-profile companies finally reached the terms of the settlement. The jury decided that Apple will be awarded $539 million in damages. 

  • Intel-VLSI Patent Infringement Case: In May 2021 a Jury in Waco Texas (Western District Court of Texas) ordered Intel Corp. to pay VLSI Technology LLC US$ 2.18 billion as patent infringement damages.  

This ruling is the second-largest patent infringement damages awarded in the history of the United States. VLSI originated as an integrated circuit (IC) manufacturer and was later acquired by Philips Electronics in 1999. Now it is part of the Philips spin-off NXP Semiconductors. The two patents involved in the lawsuit were US7523373B2 and US7725759B2 

The first one was originally issued to Freescale Semiconductor Inc. and the latter was issued to SigmaTel Inc. Both patents were later transferred to VLSI in 2019. The patents disclose inventions to increase the power and speed of processors. Intel argued that US7523373B2 is invalid since it covers work done by Intel’s engineers.  

This argument was rejected by the Jury, and it was held that Intel infringed claims 1, 5, 6, 9, and 11 of US7523373. As a result, Intel was ordered to pay US$ 1.5 Billion for the infringement. The jury also held that Intel also infringed claims 14, 17, 18, and 24 of US7725759 under the Doctrine of Equivalents and was ordered to pay $675 million as damages. 

When Does Patent Infringement Occur? 

Patent infringement occurs when a party (other than the patent holder or licensee of the patent) manufactures, imports, uses, sells, or offers for sale a patented technology without permission/license from the patent holder. 

In another way, if a person/party exercises the exclusive rights of the patent holder without getting permission or authorization from the patent holder then that person/party may be liable for patent infringement.  

How to Judge Patent Infringement? 

The patent holder holds the liability to check if there is any product infringing on his/ her patent. To identify infringement, one needs to investigate the potential market domains for products that cover the claimed features of the patent. It is necessary to prove that every element of the patented invention, or its substantial equivalent, is present in the accused product or process. 

Literal Infringement: Literal infringement is said to occur when each and every claim element of at least one independent claim of the patent has a direct correspondence with a product or device or technology. 

Infringement under Doctrine of Equivalents: When there is no literal infringement, a claim may be infringed under the doctrine of equivalents if the alleged device does the same thing and produces the same results as that of the claimed invention.  

The theory related to the Doctrine of Equivalents is based on the triple identity test, i.e., if two devices do the same work in substantially the same manner, and attain substantially the same output, they are considered to be the same, even though they vary in the name, form, or shape.  

A judge may use any of the following ways to justify a patent infringement: the doctrines of equivalents, doctrines of complete coverage, doctrines of compromise, doctrines of estoppel, and doctrines of superfluity. 

Avoiding Patent Infringement 

Following strategies may be employed in order to avoid patent infringement: 

Conducting Freedom To Operate/ Clearance search: Before launching any product in the market and preferably during the research and development phase, one should conduct a thorough search to identify any patent that can pose a threat to the commercialization of the product.  

This helps in checking for the need of licensing any patents or for directing product development in the right direction to avoid facing patent infringement charges.  

TT Consultants helps clients shape their R&D by conducting thorough FTO searches while the product is in the pre-launch phase. 

Once any such patent is identified that can be potentially infringed by your product, the following measures can be adopted in order to avoid patent infringement: 

  • Licensing Patents: The easiest approach to avoid patent infringement is by licensing or buying patents. Licensing means the patent holder allows you to use his patented invention while ownership remains with the patent holder. 
  • Designing around a patent: A protected invention is what the claims say it is, and thus infringement can be avoided by avoiding the language of the claims. Designing around a patent involves eliminating a particular element or step of a patent’s claim while designing your product. Therefore, conducting an FTO search early in the development phase helps in making some changes to modify a product to avoid infringement. 
  • Waiting for the patent to expire: If any patent is identified during the FTO search which is about to expire in some time, you may choose to wait until the patent expires. Once a patent expires, the protection ends, and the invention enters the public domain which means that anyone can commercially exploit the invention without infringing the patent.  

A US utility patent remains valid for a term of 20 years from the date of its filing and a US design patent remains valid for a term of 15 years from the date of its grant. A patent may also expire before its due date due to non-payment of maintenance fees by the patent holder. 


Patent Infringement Defences 

When a patent holder files an infringement case against an infringer, the first line of defense for the accused party is either to claim non-infringement or to invalidate the patent. 

Non-infringement: The accused party can argue that the plaintiff has failed to show that their product infringes upon the patent’s claims. This can be done by negating the arguments of the plaintiff for literal or equivalent infringement. 

Invalidating the patent: Another line of defense for the accused party is to invalidate the patent. The accused party can argue that the patent is invalid because it fails to satisfy any of the patentability requirements: patentable subject matter, utility, novelty, non-obviousness, and enablement.  

TT Consultants has helped a lot of clients avoid getting into the infringement tussle by helping them invalidate the plaintiff’s patents. 

Patent Infringement Lawsuit 

Any person/company can file a patent infringement lawsuit if another person or company is using its patented technology in their products or services without their permission. Following is the process to file a patent infringement lawsuit: 

Check the validity and enforceability of your patent: Before filing a patent infringement lawsuit, one must have to check the strength and enforceability of their own patent. For this, an extensive prior art search needs to be conducted to check if there is any prior art that can invalidate the patent. Also, due consideration should be given to the age of the patent. 

Collate information about the product: To file a patent infringement lawsuit, one must gather all the product information. Make claim charts, which show how product features are infringing the claim elements. Contact a search firm such as TT Consultants to make claim charts.  

The information will be helpful whether it can be regarded as an infringement or not. Also, collect the information which shows the impact on the business and damages due to the infringement. 

Intimate the Infringer:  Inform the infringer to make them aware of the infringement. Communicate to them the detail of the infringement and give them the particle time duration to respond. 

Hire patent Attorney:  Hire a patent attorney for legal counsel. The attorney can help to draft a patent infringement lawsuit to acquire your rights. 

Draft and file complaint: Draft a complaint letter to file in court. The complaint letter will comprise the information regarding the patent, infringer, infringing product, and plaintiff.  

Also, details of damages done to the business due to infringement need to be provided in the complaint letter. After drafting a complete complaint letter, the attorney will approach to court with a complaint to start the legal proceedings.

Patent Infringement Litigation 

Patents are enforced only by the efforts of their owners. If a patent owner believes that another party is infringing his patent, he may file a civil lawsuit for patent infringement in a district court. The complaint specifies the patent owner and the alleged infringer(s), as well as the patents allegedly infringed.  

According to US laws, the statute of limitations for a civil action for patent infringement is six years. In other words, a patent holder must file an infringement lawsuit within six years of the date of the alleged infringement to recover damages. No damages can be claimed by the patent holder for infringement committed more than six years before the filing of the complaint.  

After being served with a plaintiff’s complaint, a defendant has 21 days to answer. When answering the complaint, the defendant may include counterclaims. Most commonly the defendant asserts that the patent is not infringed and/or is invalid. 

Defendants in patent lawsuits may also initiate parallel proceedings in the USPTO, challenging the validity of the asserted patents. These proceedings are referred to as “post-grant” proceedings. The most common post-grant proceeding is inter partes review (IPR) which involves challenging the validity of a patent based on prior arts.  

A successful IPR can invalidate one or more patent claims. An IPR petition may be filed by a defendant within one year of being served with a patent infringement complaint. Once an IPR has been filed, the defendant may ask the district court to stay the patent infringement lawsuit pending the outcome of the proceeding at the USPTO. By statute, IPRs must be completed within 18 months of the challenger’s initial request. 

Not all patent infringement lawsuits reach a court trial phase. In some cases, the two parties can negotiate a settlement of the case without reaching a court trial. Each party presents evidence to the court or jury in a patent infringement trial, typically through live testimony and documentary evidence.  

Patent infringement proceedings may also involve ”Markman hearings” where the judge examines evidence from all parties on the appropriate meanings of relevant keywords used in a patent claim in order to resolve issues of claim construction. The final verdict of the jury should be unanimous and in the case of proven infringement, the jury states some monetary damages to award to the patentee for infringement. 

Punishment for Patent Infringement 

When a court determines that someone has infringed another’s patent, then the infringer can face several penalties and must pay damages to the patent holder. The damages are paid either in the form of actual damages or a reasonable royalty for unauthorized use.  

Actual damages depend on lost profits the patent holder would have realized, and reasonable royalty depends on the type of product, other royalty arrangements, etc. The patent holder has also the right to include the fees of the attorney in the damages. 

In addition to infringement damages, a patent holder may stop the infringer from continue producing infringing products/technologies. The court may issue issues a permanent injunction after the infringer is held liable for violating the patent. 

A preliminary injunction may be requested by the patent holder in some cases. A preliminary injunction is an order granted at any stage of a procedure, prior to the judgment or final order, to restrict the opposite party from engaging in certain conduct. The preliminary injunction is granted if there is a considerable likelihood of success on the merits of the case and if the infringer continues performing the activities while the case proceeds. 


1. What is a reasonable royalty?  It’s a way of evaluating damages in patent infringement cases. It is a calculation of the amount the patent holder would have received from the infringer in a hypothetical license negotiation at the time the infringement began.  2. What is the importance of a Cease-and-Desist letter?  Patent holders may employ cease and desist letters as part of their enforcement strategy. It is a notice to the infringer from the patent holder to stop an alleged infringement activity. This letter can serve several benefits to the patent holder. If the recipient complies with the letter, the time and cost of litigation are saved. Even if the recipient does not comply, the letter may lead to a licensing agreement with the other party. This letter may even be useful in any future court proceedings for proving willful infringement and claiming enhanced damages if the alleged infringer ignores the letter.  3. What is the penalty for Willful Patent Infringement?  In Willful infringement, the court can award up to three times the actual damages incurred.  Learn more – Link  4. What are the types of Indirect Patent Infringement?  There are two types of indirect infringement: (i) Contributory infringement and (ii) Induced Infringement.  Learn more – Link  5. What published materials are used to produce patent infringement?  Product disclosures, videos, manuals, datasheets, whitepapers, press releases, etc., and not research papers, thesis, and patents.  6. What is a patent licensing? It refers to the process of assigning the ownership of a patent to a third party so that they can make, use, and sell your invention in an exchange for pre-decided royalty. 

WHY TT Consultants?

  • TTC has a highly experienced team (with over 12 years of expertise in patent infringements) in a variety of domains to conduct patent infringement analysis.
  • Various advanced proprietary internal modules such as video caption search module, standard search module, and website crowdsourcing module which help TTC in the patent infringement analysis.
  • TTC has an experienced software team and advanced software tools to analyze complicated source codes (application software, driver software, system software, or firmware) in order to give essential evidence from the product/software source code in software patent infringement investigation. TTC has various internal labs to do product teardown to make high-value EoU claim charts.
  • TTC collaborates with top institutes/labs on core reverse engineering challenges, such as proving patent infringement in the semiconductor industry.
  • Color-coded easy to understand claim charts
  • Litigation-ready claim charts.

About TTC

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