Many inventions are not entirely new but instead build upon previous inventions and provide meaningful improvements. This might involve adding an element to an existing invention, putting an existing invention to a new and unexpected use, or invigorating an old product with a new form of technology. For example, adding a new technology to an old product occurred when companies started using microprocessors to control devices that had been controlled by analog circuitry. These companies succeeded in obtaining patents for the improved devices, which covered the differences between the original version and the new version.
There are two main types of improvement patents, which are known as addition inventions and substitution inventions. An addition invention adds a component that previously was not present in a product or process. A substitution invention replaces a certain product or process with a new product or process that is more efficient in accomplishing the same purpose. When Amazon substituted one-click purchases for its online shopping cart, it obtained a patent for the one-click process as a substitution invention.
Getting a patent for an improvement may not seem worthwhile, especially if you consider the costs of pursuing a patent and enforcing your patent rights. However, sometimes an improvement can make a huge difference in the usefulness of a product or its attractiveness to consumers. If the improvement separates your product from the competition, you may want to patent the improved version so that your competitors do not erase your advantage. Many people feel that improvement patents are trivial, but incremental changes in a product often have spurred broader changes in an industry and helped push innovation forward.
Sometimes an inventor or a company will discover that a patented product, or a component of a patented product, can be used for a purpose that is different from what the patent owner contemplated. If the purpose is sufficiently distinct, they can get a patent for that use. A company that used an ointment made to treat cow udders to alleviate baldness in people, for example, was able to obtain a patent for this new use of the ointment. The Federal Circuit upheld the validity of the patent, even though the second company did not add anything to the composition of the ointment.
