And that would be why Apple does not have a patent on pinch to zoom. They just have patents related to it.
Exactly. Their patent has to do with the data processing that goes on behind the scenes to identify the fact that two distinct points of contact are present on the screen, as opposed to only one point of contact, or three or more points of contact.
And then it goes on to describe the data processing required to identify the fact that these two points of contact are moving.
Next, it describes the data processing required to compute the trajectories, velocity, and acceleration of each point of contact, as well as the relative angles of these two trajectories with respect to each other.
Then it describes the computational process that uses all of this data to distinguish the "pinch" gesture from any other kind of two-fingered gesture.
Honestly, the fact that the UI happens to decide that a "zoom out" operation is the appropriate response to a "pinch" gesture, is rather inconsequential compared to the specific mechanism that was employed to discover the fact that a "pinch" was being applied in the first place.
If tablets had been using that exact same set of computational processes for decades to identify the fact that a "pinch" was being applied, then frankly, Apple's patent ought to be meaningless.
On the other hand, if it can be shown that those tablets from decades ago were using even a slightly different computational process to identify the fact that a "pinch" was being applied, then they are not relevant to a criticism of the patentability of Apple's implementation.
