Patented inventions must be different from existing knowledge or previous inventions, otherwise known as prior art. What is prior art?

Prior art is:

• anything in public use or sold in the United States for more than a year prior to the patent application’s filing date;
• anything publicly known or used by others in this country before the invention date;
• anything made or built in this country by another before the invention date;
• prior patents issued more than a year before the patent’s filing date or any time before the date of invention;
• prior publications dated more than a year before the patent’s filing date or any time before the date of invention; or
• U.S. patents with a filing date prior to the invention date.  What are Invention date and One Year Rule?

There are three types of differences:

1.physically different

The new invention must have at least one piece of hardware that is physically different from prior art.  This can be an addition or a subtraction of hardware.  It may also be something less obvious than that.  For example, a physical difference may be that the invention works in a different temperature range or a different mode than what was indicated by prior art.  These will all satisfy the novelty criteria for patenting a new invention.

2. new combination

Novelty may include new combinations of prior art.  In other words, two previously patented inventions are prior art.  But if they are combined in such a way that is not already patented, then this new combination is considered novel.  

3. new use

A patented invention’s use is described in the claims section of its patent application.  If you think of a new use that isn’t discussed in the patent application, then that new use satisfies the novelty component.  This new use of an already patented invention may be patentable.