There is a differenct between “novel” and “invented”. Consult your dictionary.
Roget's New Millennium™ Thesaurus lists "original" as a primary synonym for novel.
"Invented" can mean fabricated, or it can mean to produce something as an original idea.
Obviously I meant the latter in my post. Although toward the other usage, it is fair to say that "he invented a novel idea" -- in that the invention is a fabrication of his imagination.
So in this case there is no differenct at all, you see.