Infringement

Someone is selling something that looks like your invention. Whether that is infringement has almost nothing to do with how similar it looks.

In simple words

Doing, without the patentee's permission and in the country where the patent is in force, something the patentee has the exclusive right to do - making, using, offering for sale, selling or importing what the claims cover.

Think of it as

Did their product cross your fence line - every part of it?

Why it matters

Infringement is decided claim by claim, element by element. If your independent claim requires five features and the competitor's product has four of them, there is usually no infringement of that claim, however similar the products look.

A simple example

Your claim requires “a controller that adjusts flow in response to a temperature signal”. A competitor adjusts flow in response to pressure. The products look identical on a shelf; the claim is not met.

Common mistake

Reading the description instead of the claims. Courts construe the claims, in the light of the specification - not the marketing.

Where it comes from

Patents Act 1970 - section 48 (rights), section 104 onwards (suits), section 107 (defences), section 107A (Bolar and parallel imports)