The Basics of Patent Law

Patents protect inventions and offer inventors a limited monopoly. Such a monopoly is enforceable in court by a patent holder who believes that their intellectual property has been improperly used or exploited.


Congress created patentable subject matter to include “anything under the sun that is made by man.” However, this broad definition has limits.


Patents are issued for new inventions and grant their holders the right to exclude others from making, using or selling the patented item for 20 years. Historically, patents protected tangible scientific inventions like circuit boards or car engines but have been expanded to include a wider range of items including business methods, coding algorithms and genetically modified organisms.

In order for an invention to be patentable it must involve subject matter that is statutory, novel and useful. Inventions must fall within one of the categories of patentable items in the Patent Act, which include processes, machines, manufactures and compositions of matter. Moreover, the invention must be novel and nonobvious; that is, it cannot have already been described in a printed publication or in public use or on sale prior to the inventor filing his or her patent application.

The invention must also be described sufficiently to allow a person of ordinary skill in the art to make, use or practice the invention. This is known as enablement. The patent applicant must also disclose his or her preferred embodiment of the invention, as specified in 35 U.S.C. SS 112 and is often referred to as the “best mode” requirement.

Filing a Patent Application

When an inventor believes their invention is novel, useful and non-obvious they need to file a patent application with the relevant governing body. Patent applications typically start with a description of the invention and end with numbered claims that define the scope of protection for the invention.

Each patent application is unique to the invention and is individually examined by a patent examiner. During the examination process the patent examiner will compare the invention with prior art and determine whether it meets the statutory requirements.

Three-Minute Legal Tips (TMLT):

When a patent application is filed the applicant must include a detailed description of the invention and provide a set of drawings of it. The description should be written in a way that would allow someone skilled in the invention’s field to create and use the invention. It also needs to describe the inventive step, ie what makes it different from existing technology and why it is an improvement. The application can be amended during the process and a patent is only granted when all amendments have been considered.

Patent Examination

After the filing deadline, a patent examiner reviews the application and determines whether the claimed invention meets all legal requirements. This includes evaluating the specification for clarity and whether claims clearly, concisely and distinctly claim the invention. The examiner also conducts a search of United States patents and published applications, foreign patent documents and available literature to see whether the invention is novel and nonobvious.

A patent examiner writes a communication to the applicant, called an Office Action, which can include a rejection of some or all the claims in the application. Your patent attorney, with your input, prepares a response to the examiner, pointing out why some or all of the claims should be allowed.

The law requires that the examiner give full and fair reasoning in an Office Action. This helps reduce the chance that the application could be misinterpreted by a court, especially in a later patent infringement lawsuit. The law also allows for accelerated examination or super-accelerated examination in certain circumstances. This applies to applications that have a counterpart in a participating Patent Cooperation Treaty country, or an international application that is the national phase of a PCT application.

Patent Review

Patents serve two purposes: They put the world on notice that an inventor has created something new, and they give the inventor a legal right to prevent others from using, selling, or making the invention in the United States for twenty years. The contents of a patent must be carefully drafted to ensure they are clear and enforceable.

A professional lawyer can conduct a thorough patent application review to ensure that the legal document is error-free and complies with the US laws. The attorney also analyzes the content to make sure that the terms and conditions are comprehensible for all parties involved in the agreement.

The AIA introduced two procedures that enable a third party to challenge the validity of an issued patent without going through court litigation. These procedures are known as Post Grant Review and Inter Partes Review. Both of these proceedings are substantially shorter and cheaper than court litigation. If by a preponderance of the evidence it is determined that a claim or all claims are invalid, the claim or claims will be stricken or revoked.

Patent Infringement

Patent infringement occurs when a product or process infringes on an inventor’s patent rights. The patent holder can sue for infringement and win damages from the person or company infringing on the patent. It is important to perform a thorough patent search at the invention stage and review all known competitor products for potential infringement. Ignoring a patent or trying to play dumb in court will only hurt you in an infringement case.

There are several types of patent infringement. Direct infringement is when someone violates a patent directly by making, selling, or offering to sell a product that has all the elements of the patent claim. Indirect infringement can occur through inducement or contributory infringement.

A court determines if there was infringement by analyzing the patent using claim construction, which involves comparing the defendant’s product to the patent claims. The claim language, the written description in the patent specification, the prosecution history, and extrinsic evidence all play a part in the analysis. Literal infringement exists if the defendant’s product contains every element included in the patent claim.