Inventors often believe that their invention is not patentable because it is an improvement of a patented invention.
However, an improvement of a patented invention is patentable provided that, in view of the state of the art, it:
involves an inventive step (ie, it is not obvious); and is susceptible of industrial application .
The 'state of the art' is defined as everything made available to the public before the date of filing of the patent application. Continue Reading