The company has since filed a lawsuit against Apple, claiming that the patent they infringed on is called “shared feedback”. According to the patent, it describes how software could be used to show a preview of information through a light press, and take action from a firmer press, which isn’t 100% Force Touch/3D Touch, but it does sound similar.
They also claim that Apple’s devices infringe upon another patent for “tactile sensations”, where it delivers a specific feedback in response to a particular action. For example if you have used 3D Touch, you know that pressing down hard will cause the phone to “vibrate” a little, like how Apple simulates clicks on the trackpad of its more recent MacBooks without it actually clicking.
No word on how much Immersion is suing Apple for and how much in damages they are seeking, but no doubt this will be rather troublesome for Apple if Immersion were to win the lawsuit.