It is difficult to identify a single patent that has earned the most, as the value of a patent can be difficult to quantify and can depend on a variety of factors such as the industry, market demand, and licensing agreements. However, there are some patents that have been very valuable and have earned their inventors or assignees significant amounts of money.
One example is the patent for the technology used in the iPhone, which has been estimated to have earned Apple billions of dollars in licensing fees and royalties. Another example is the patent for the drug Humira, which has been one of the top-selling prescription drugs for years and has earned billions of dollars in revenue for its manufacturer, AbbVie.
In general, patents in the pharmaceutical and technology industries tend to be some of the most valuable, as they can protect valuable intellectual property that can be difficult for competitors to replicate. However, the value of a patent can vary widely, and many patents never earn their inventors or assignees any significant amount of money.