Apple Offered To Replace Touch Screens With Radars
Apple has proposed a new operating principle for touch screens. Instead of the many capacitive sensors that are commonly used today, engineers suggest installing four miniature radars in the corners of the screen that will determine the position of the finger. This will potentially reduce the thickness, power consumption and cost of smartphone screens, as well as teach them to recognize a finger that does not touch the screen, the authors of the published patent application said.
As a rule, modern smartphones, tablets, and laptops with a touch screen use a capacitive layer to track touch. In it, above the layer of the screen itself or between its pixels, there are many electrodes. They can detect a finger or other conductive object by changing the voltage. This technology has proven itself well, but still has disadvantages, including it adds extra thickness to the screen, as well as cost: in laptops and other large devices, the difference between a touch screen and a regular screen is usually several tens of dollars.
Apple engineers have proposed an original alternative to capacitive screens-small radars. The authors of the patent application suggest using at least one radar but mostly describe a design with two or four radars in the corners of the screen. They emit radio waves, register reflected signals, and use them to determine the two-dimensional or three-dimensional coordinates of a finger or other object.
Judging by the fact that the authors suggest tracking not only the position in the plane but also the height of the object, you can interact with this screen without touching the surface.
The authors assume that the accuracy of determining coordinates will be less than a millimeter. But since most of the time a person does not touch the screen, to save energy, a mode can be used in which initially radars scan the space near the screen with a small resolution, and switch to the exact mode of operation when an object is detected.