How do Patents Work


A patent is a grant of legal protection for an invention, issued by a government agency, that gives the inventor the sole right to make, use or sell an invention for a defined period of time. The inventor may assign the patent to others, who may then exercise the rights granted to them by the inventor for the duration of the patent. The inventor may also license the patent to others, allowing them to use the rights obtained under the license for an agreed period of time.

As part of the patent application process, the invention is disclosed to the public. Once the period of protection expires the invention becomes public property.

The goal of patent law is to encourage innovation by granting inventors the exclusive legal right to profit from their original inventions. Inventors may be motivated by the potential for profit, and their investors are more confident that they will be able to earn profits from successfully patented inventions.

Given the cost and complexity of the patent process, sometimes it is not beneficial to obtain a patent. When there is a very limited market for an invention or where it is likely that the validity of the patent will be challenged, a careful market analysis is warranted before incurring the expense associated with the patent application process.

What Inventions Can Be Patented

In order to qualify for patent protection, an invention must be new, useful, and not obvious to somebody with ordinary skill in the area related to the invention. In simple terms, the requirements are as follows:

  • The Invention Must be New: In the most general sense, an invention is new if it has not been previously invented by somebody else. An invention may not be considered new if:

    • The invention was described in a patent or printed publication before it was invented by the person applying for a patent;

    • The patent was published in such a manner more than one year before the patent application was filed;

    • The invention was in public use or on sale for more than a year before the patent application was filed; or

    • Other people knew of or used the invention in the United States before it was invented by the person applying for a patent;

  • The Invention Must be Useful: To be useful, an invention must provide some form of benefit. That is, the invention must be useful for a legitimate purpose.

  • The Invention Must Not be Obvious: The obviousness of an invention is the most subjective element of any patent application, as reasonable minds may differ as to whether a particular idea or invention is obvious.

When the obviousness of an invention is evaluated, the question is not whether an invention seems obvious in retrospect, but whether it would have been obvious to somebody with ordinary skill in the area related to the invention at the time the invention was made. The mere fact that a patent reflects a simple idea does not mean that it is obvious.

What Are the Types of Patent

There are three primary types of patent: Utility patents, design patents, and plant patents.

  • Utility Patents: Most patents filed are for utility patents, a category of patent that protects processes, machines, articles of manufacture, or compositions of matter. Protection generally lasts for twenty years from the application filing date.

  • Design Patents: A design patent protects ornamental designs for manufactured items. Although the design may not change the utility of the invention, the design, shape or other ornamental feature may still be protected by patent. Design patents last for fourteen years after the date that the patent is granted.

  • Plant Patents: A plant patent protects asexually reproduced plants, and lasts for eighteen years from the date that the patent certificate is issued.

Patent protection is available for nearly all manufactured items.

How to Obtain a U.S. Patent

In very simple terms, a U.S. patent is obtained by filing an application for a patent with the U.S. Patent and Trademark Office (USPTO). The USPTO reviews the patent application against existing patents and patent applications to determine if a patent should be granted.

Who May Apply for a Patent

In the United States, only the inventor may apply for a patent. This is true even if the inventor is obligated to assign the invention to another person, such as an employer. If an invention is created by more than one person, all of the inventors involved in its creation must jointly apply for the patent.

Patent law includes provisions designed to protect employers, in the event that an employee refuses to assign the rights to a patent as required by the terms of employment, or where the inventor is deceased and is thus unable to apply for the patent.

Preparing to File a Patent Application

Before applying for a patent, an inventor who hopes to obtain a patent must consider whether an idea will qualify for patent protection if developed into an invention. The inventor will have to search for prior art, existing inventions that might so similar to the inventor's idea that they disqualify it from patent protection. During the process of invention, the inventor should keep good records of the invention process. When preparing the patent application, the inventor needs to avoid making mistakes that might invalidate the application or make it possible for competitors to avoid having to license the patent in order to make an equivalent product.

Although it is possible for an inventor to obtain a patent without the assistance of a lawyer, a legal professional can help ensure that an invention will qualify for patent protection, that a patent application will be granted, that any patent that is obtained will be enforceable, and to maximize the protections obtained through the patent process.

Searching Prior Art

Before filing an application for a patent, an inventor should search existing patents and prior art for any evidence that the invention already exists:

  • Existing Patents - An inventor, or an attorney or service hired by the inventor, may search through existing patents to try to find any prior patents or patent applications that suggest that the new invention lacks novelty.

  • Prior Art - The term, prior art, refers to all information that is available to the public in any form that suggests that an invention has previously been created or is already known.

Due to the vast number of patents on record, and the enormous quantity of sources of prior art, it is next to impossible to be certain that the novelty of an invention won't be challenged after-the-fact based upon a claim that it infringes a patent that went undetected in a prior search, or that the patent should not have been granted based upon a claim that the invention was not novel.

The Patent Application

An application for a patent is a formal document that fully describes an invention in a legally sufficient manner. The application includes a specification, a series of claims, and, if necessary, drawings or illustrations to assist in understanding the invention.

  • Specification - The specification provided in a patent application must describe the invention in such a manner that any person skilled in the area pertaining to the invention will be able to obtain all information necessary to make and use the invention. It must also describe the best mode known to the inventor for practicing the invention as of the time the patent application is filed.

  • Claims - The claims define what an inventor may exclude others from making, using or selling as a result of a successful patent application. It is thus very important that the claims included in a patent application be drafted in as broad a manner as possible, so as to provide maximum protection for the invention, but at the same time that they be sufficiently narrow so as to avoid invalidating the patent on the basis of prior inventions.

  • Drawings and Illustrations - If necessary to enable a person reviewing a patent application to understand the invention, a patent application must include drawings. Most patent applications benefit from the inclusion of drawings. When it is necessary to submit drawings with a patent, it is sensible to have the drawings created by an expert who is familiar with the governing rules and standards promulgated by the patent office.

Once a patent has been filed, an inventor may mark an invention as "patent pending" or "patent applied for".

After the patent application is submitted and the filing fee is received, the application is reviewed by the patent office. Following review, the patent office may accept the application, reject the application, or request that the application be amended or clarified.

Due to the complexity of the application process and of dealing with issues that may arise during the review process, it common for inventors to seek the assistance of registered patent attorneys when preparing a patent application.

Alternatives to Applying for a Formal Patent

An inventor who does not want to go through the full patent application process before producing, implementing or marketing an invention, or wants to avoid the public disclosure requirement associated with a patent application may prefer to seek a provisional patent or to treat the invention as a trade secret.

An inventor will benefit from consult an intellectual property lawyer before choosing between formal patent protection and other forms of protection.

Provisional Patents

A provisional patent is obtained through the USPTO, but with a smaller filing fee and far fewer formalities than an application for a formal patent. By filing for a provisional patent, an inventor will gain protection from the possibility that another inventor might attempt to patent a similar invention.

The USPTO does not examine the provisional patent. However, to avoid a later challenge, the application for a provisional patent must include a complete description of the invention, and must also include drawings if they are necessary to understand the invention.

Once the provisional patent application is filed, the inventor has one year to decide whether to file an application for a formal patent. During that year the inventor may mark the products that are covered by the provisional patent as "patent pending". The inventor may also market the invention to others with far less concern about their attempting to copy the idea behind a product or process without either purchasing or licensing rights from the inventor.

Under narrow circumstances, an inventor may be able to file a second provisional patent application instead of filing a formal patent application, in order to extend provisional protection for a second year. As a mistake as to eligibility or in the application may cost the inventor the ability to obtain patent protection, it is best to work with a patent lawyer when deciding if it is possible or appropriate to file a second provisional patent application.

If the twelve month provisional period expires without further action from the inventor, the provisional patent application is deemed abandoned. Once the application is abandoned, any prior public disclosure of the invention may potentially prevent the inventor from subsequently obtaining patent protection.

Trade Secrets

A trade secret is a device or technique that is used by a company in the manufacture or products, but that is kept secret from the public.

The advantages of trade secret protection are that the inventor does not incur the cost of obtaining a patent, and that trade secret protection can be maintained indefinitely, as long as the device or process remains secret. The primary disadvantage of trade secret protection is that it offers no protection in the event that another inventor independently invents or reverse-engineers the same machine or process.

What Happens When a Patent is Violated

Once an inventor obtains a patent, the inventor is responsible to enforce the patents. That may create a context for a David versus Goliath battle, with an inventor accusing a large company of violating his patent, and with the large company devoting considerable resources to challenging the validity of the patent or to distinguish its own invention or process from that outlined in the inventor's patent.

Patent litigation is almost always complex, and is always very expensive. Often an inventor may find it easier to try to sell the patent to the infringing company, to negotiate a licensing fee with that company, or to sell or license the patent to another company that will take over the defense of the patent in litigation, as opposed to trying to bankroll and participate in patent litigation and appeals.

In the event that a patent infringement is established in court, the patent holder is entitled to recover a reasonable royalty, or to recover the profits lost as a result of the violation. Additional penalties may apply.

If you are an inventor whose patent is being violated, it is a very good idea to consult with an attorney about your rights and remedies.

International Patent Protection

A patent applies only within the borders of the nation that grants the patent. Thus, if your invention has a market in foreign nations, you will benefit from seeking patent protection in those nations.

In most cases, in order to maximize your protections you should file for any foreign patents within one year of the date you filed your initial patent application with the USPTO. If additional time is required to file foreign patent applications, consult a patent lawyer about your rights under the Patent Cooperation Treaty, pursuant to which you may be able to obtain up to eighteen additional months to file foreign patent applications.

Considerations for Inventors

In order to maximize the probability that they will be able to protect their inventions and defend their patents, inventors should do the following in advance of filing an application for a patent:

  • Keep careful, dated, accurate records of their invention process, starting at the earliest stage of the conception of their idea, and detailing the entire development process;

  • Keep Good Records - Maintain records of the entire invention process that are periodically dated, witnessed, dated and signed by trustworthy, independent witnesses who understand the invention. Witnesses should be willing and able to testify on the inventor's behalf if the patent is challenged.

  • Maintain Confidentiality - Have all witnesses, and any other individuals to whom details of the invention are disclosed prior to application for a patent, sign confidentiality agreements;

  • Keep Good Records - Refrain from offering an invention for sale before applying for the patent;

  • Don't Publicly Disclose the Invention - Refrain from public use or disclosure of an invention;

  • Don't Publish Details - Refrain from publishing articles describing the invention prior to applying for the patent;

  • Work With a Qualified Lawyer - Work closely with a patent attorney to ensure that the patent application details how your invention differs from and improves upon prior inventions, and contains all relevant and useful information and references;

  • Communicate With Your Lawyer -Keep your attorney informed of any new developments or changes you make, in relation to your invention.

An inventor should not attempt a so-called "poor man's patent". The idea behind a poor man's patent is that you can put documentation of an invention into an envelope, seal it and mail it to yourself as proof of the date of the invention. However, in the event of a challenge to the validity of a patent or its date of conception, such an envelope of documents is of next to no value.

Copyright © 2003 Aaron Larson, All rights reserved. No portion of this article may be reproduced without the express written permission of the copyright holder. If you use a quotation, excerpt or paraphrase of this article, except as otherwise authorized in writing by the author of the article you must cite this article as a source for your work and include a link back to the original article from any online materials that incorporate or are derived from the content of this article.

This article was last reviewed or amended on Aug 2, 2016.