In order for a patent claim to be valid, it must propose a concept, idea, or item that is useful, novel, and non-obvious. These terms may seem vague, but they have specific legal meanings that correspond with federal patent law. And even when an idea or invention is technically nonobvious, at least from an engineer's perspective, it may not meet the legal criteria.
In any event, intellectual property (IP) attorneys are trained to make these often minute distinctions when counseling inventors or business organizations. The terms "useful," "novel," and "non-obvious" -- as they relate to the criteria of what may be patented -- are explained in greater detail below.
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The term "useful" means that the subject matter has a useful purpose. It also requires that the item is operable, since a machine that can't perform its intended purpose cannot be considered useful in the ordinary sense of the word. Since the decision over whether an invention is useful could be considered subjective, the U.S. Patent and Trademark Office (USPTO) has corresponding examination guidelines. These include the following:
"Novelty" is strictly defined by patent law, essentially referring to the originality of the idea. An invention cannot be patented if:
These rules don't prevent a person from patenting an improvement to another invention, however. For example, tire makers have long known the formulas for making tire rubber. But what if an inventor found a way to make tire rubber twice as long-lasting by slightly changing the chemical composition? This could well be a patentable improvement as long as the difference wasn't obvious.
Even if a new invention differs in one or more ways from another patented invention, a patent may still be refused if the differences would be obvious. Non-obviousness is defined as a sufficient difference from what has been used or described before that a person having ordinary skill in the area of technology related to the invention would not find it obvious to make the change.
For example, sodium chloride (table salt) and potassium chloride (a chemically similar salt) can often be used interchangeably. A chemist working to improve road salt would consider it obvious to substitute potassium chloride for sodium chloride, so a formula that simply made this substitution in an already patented road salt formula would not be patentable.
Is Your Idea Patentable? Get a Free Review from a Patent Law Attorney
Patent law is quite complicated, even for IP attorneys. If you have a valuable invention or idea that you would like to either sell, take to market, or otherwise protect, contact a patent law attorney near you. An attorney can help you understand the law, review your ideas, and help you fill out any necessary paperwork. Get a free initial consultation.