Types of Patents
Patents come in three distinct types: utility, plant, and design. Each protects a different aspect of an invention, and choosing the wrong type can leave your work unprotected. This section covers what each type covers, how they differ, and clears up some common misconceptions about how patents actually work.
Types of Patents and Criteria
Utility patents protect the functional aspects of an invention. They cover processes, machines, articles of manufacture, and compositions of matter. To qualify, an invention must meet three requirements:
- Novel: not previously known or used by others
- Non-obvious: not readily apparent to someone skilled in the relevant field
- Useful: serves some practical purpose
Utility patents last 20 years from the filing date and give the holder the right to exclude others from making, using, or selling the invention. Common examples include new pharmaceutical compounds, improved manufacturing processes, and innovative software algorithms.
Plant patents protect new and distinct varieties of asexually reproduced plants. "Asexually reproduced" means the plant is propagated without seeds, through methods like grafting, cutting, or budding. The plant also cannot be one found in an uncultivated state in nature. To qualify, a plant variety must be:
- Novel: not previously known or described
- Distinct: clearly distinguishable from existing varieties
- Asexually reproducible: capable of being propagated without seeds
Plant patents also last 20 years from the filing date. Examples include disease-resistant rose cultivars, seedless watermelon varieties, and certain genetically engineered crop plants.
Design patents protect the ornamental appearance of a functional item. They cover only the visual, non-functional aspects of an article of manufacture. The requirements are:
- Novel: not an imitation of an existing design
- Non-obvious: not a trivial modification of an existing design
- Ornamental: covering purely decorative features, not how the item works
Design patents last 15 years from the issue date (not the filing date, which is different from the other two types). Examples include unique furniture shapes, distinctive product packaging, and iconic beverage bottle designs like the Coca-Cola bottle.
Features of Plant and Design Patents
Plant patents are narrower in scope than you might expect. Each patent covers a single plant variety, not an entire genus or species. The application must include a complete description of the plant's distinguishing characteristics and its method of asexual reproduction. Drawings or photographs can supplement the written description but aren't always required.
Design patents rely heavily on visuals. Drawings or photographs are essential to the application because they define the scope of protection. One useful convention: broken lines in the drawings indicate portions of the article that are not part of the claimed design. For example, if you're patenting a unique shoe sole pattern, you might use broken lines for the upper part of the shoe to show that only the sole design is being claimed.
Design patents protect how something looks, not how it works. If the appearance of your product is driven by its function, a design patent won't cover it.
Common Patent Misconceptions
"A patent gives you the right to make, use, or sell your invention." Not quite. A patent is a negative right: it gives you the right to exclude others from making, using, or selling your patented invention. You don't automatically get the right to commercialize it yourself. You still need to comply with all other applicable laws and regulations. For instance, a patented drug still needs FDA approval before it can be sold.
"Patents protect you worldwide." Patents are territorial. A U.S. patent only protects you in the United States. If you want protection in Japan, the EU, or anywhere else, you need to file in each jurisdiction separately. International agreements like the Patent Cooperation Treaty (PCT) can streamline the filing process across multiple countries, but they do not create a single global patent.
"All patents are utility patents." Utility patents are the most common type, but plant and design patents serve important roles. Confusing the types can lead to filing the wrong application entirely.
"Once granted, a patent is always valid and enforceable." Patents can be challenged and invalidated even after they've been granted. This can happen through post-grant review proceedings or litigation. Common reasons for invalidation include prior art the examiner didn't consider, lack of novelty or non-obviousness, and inadequate disclosure in the patent application.
Patent Application Process and Maintenance
Patent prosecution is the back-and-forth process between the applicant (or their attorney) and a patent examiner at the patent office. The examiner reviews the application to determine whether the invention meets patentability requirements, and the applicant can respond to objections or rejections.
A few key procedural concepts to know:
- Provisional applications establish an early filing date and let you use the label "patent pending" for 12 months. They're less formal and less expensive, but they don't mature into a patent on their own. You must file a full (non-provisional) application within that 12-month window.
- Continuation applications let you pursue additional claims based on an earlier-filed application while keeping the original filing date.
- Maintenance fees are required after a patent is granted to keep it in force. Miss a payment, and the patent can expire early.
- Patent term adjustment may be added to compensate for delays caused by the patent office during prosecution, extending the patent's effective life.