Apple's Legal Arsenal Grows as the Company is Granted Another Key Multitouch Patent

The United States Patent and Trademark Office recently published that the Cupertino, California company now owns a crucial patent, one which described how touch events are recognized by touchscreen devices. This specific patent was one of the “200+ Patents for new inventions” that Jobs was pushing for when the iPhone first debuted according to a report from Patently Apple. The newly granted patent focuses on the oscillator signal and circuit of a touchscreen-equipped device, an integral invention directly related to how users interact with their multitouch products.

Apple stated the following in their filing:

In general, multi-touch panels may be able to detect multiple touches (touch events or contact points) that occur at or about the same time, and identify and track their locations.

Before the introduction of the iPhone in 2007, most of the touch-capable devices relied on single-touch input like resistive touchscreens. The current legacy technology senses a touch when two electrically resistive sheets separated by a small gap are connected by the push of a finger or stylus, which in turn creates a voltage division that, is detected by a device controller that records the charge along the x and y axes. The resistive displays are limited in the sense that they can only recognize single inputs no matter how many objects are touching the screen.

One method that can be used to record multiple touches at a time is to generate an oscillating signal circuit that can power and clock inputs over a substrate as in a capacitive touchscreen display, however it should be noted that it is difficult to create a precise circuit-based oscillator. What Apple’s patent provides is a solution to the capacitive touchscreen problem by using calibration logic circuitry, which compares the signal oscillation against a reference signal and tunes the clock frequency accordingly. The invention provides for an accurate capacitive display that can not only sense multiple touches but also detect hover or near touches which are also recognized as “touch events.”

The wording of the patent states that the invention could apply to computer devices such as desktops, laptops, tablets, or handhelds, including digital music and video players, and mobile telephones. It even mentioned public computing systems such as kiosks and ATMs. In the end, what it does is add to the company’s already formidable legal arsenal.