I invented a, lets just call it a simple circuit board, 10 years ago. I sold about 2000 of these so they are in the public. The way I understand it is if you didn't patent it within the first year you are out of luck.

Can I change it a little bit, ie put on an LED light (thus improving it), and then applying for a patent? Lets just assume nobody else had patent it.


3 Answers 3


You are correct, after disclosure of an invention the inventor has 1 year before patent rights expire. Since you were selling this invention, and the 1 year time period has lapsed, this invention can not be patented.

Yes, a non-obvious and useful improvement to existing prior art can be patented. Undoubtedly, there have been numerous improvements (and patents) in this area since the time you originally invented the original project. Your next step is to search 'prior art' to see what has been invented since your previous invention was on the market.


Depends on what country you are in.

In many countries, the 1 year does not apply. Any public disclosure or sale means you have no patent rights at all.


You could only patent the changes as an improvement to the existing thing. And said changes would have to meet all the requirements for patentability in and of themselves.

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