FWIW patents cover inventions, not ideas. An invention is there implementation of an idea. They also require the submission of a workable embodiment in order to be granted.
USA does blur the lines with its broad software patents and business method patents. But we in Europe have software patents to, they're just for inventions, not ideas.
This post is my personal opinion and does not relate to my employment.
The implementation of an idea is a specific physical machine (not class of machines) or an active production process. The moment you start talking about how similar one machine or process is to some other machine or process (the core of any patent infringement case) you're back in the realm of ideas.
It's the idea of an implementation that is patented, not the implementation of an idea.
This is particularly obvious when it comes to software patents as the entire process being patented concerns the manipulation of abstract information, which places even the implementation of the idea squarely in the realm of ideas. Even if that patent office requires the software to be "embodied" in some general-purpose computer before granting the patent, the patent covers the abstract data-manipulation algorithms even when they are reimplemented in different software running on a completely different kind of computer—which puts the lie to the idea that this "embodiment" has any relevance at all to the patent.
USA does blur the lines with its broad software patents and business method patents. But we in Europe have software patents to, they're just for inventions, not ideas.
This post is my personal opinion and does not relate to my employment.