- Sep 8, 2021
On November 3rd, the U.S. Patent and Trademark Office officially published a series of newly granted patents for Apple Inc. including the patent for detecting force or touch on input surfaces such as the side of an iPhone or for force touch on a display with an Apple Pencil.
This patent was originally filed in Q3 2018 and this technology could be used on other devices like MacBooks or the iMac other than the iPhones in the future.
How will it work?
Apple’s granted patent covers devices, methods, and systems- and electronic devices having them- that can detect a press, touch, or other input on input surfaces, such as the side of a device like an iPhone and display surface that Apple Pencil will be able to work with.
According to a Patently Apple report, all of these could include an optical waveguide, positioned on or adjacent to the input surface, into which a laser diode inserts light.
This light may be inserted and undergo total internal reflections as it traverses the length of the optical wave guide until, in some embodiments, it reflects from a full or partial reflector at an end of the optical wave guide, the end being at a known distance from the insertion location of the light.
Now, in the absence of a user’s touch on the input surface, the inserted light reflected from the reflector may be received back into the laser diode’s lasing cavity. This causes self-mixing interference of the light existing within the laser cavity and the reflected light.
Such self-mixing interference can alter an operational parameter of the laser diode. This may be detected by processing electronics coupled with the laser diode and correlated with the known distance to the reflector from the insertion location.
The optical waveguide may also include one or multiple light out-coupling elements including transmissive light out-coupling elements, reflective light out-coupling elements, in-wave guide tilted Bragg gratings, or another type. This light could be positioned in the optical waveguide at or near respective input sensing positions on the input surface.
As a user presses or touches the input surface at a sensing location near a particular light out-coupler, light in the waveguide can exit it at the location of that light out-coupler. Some of the embodiments are reflected into the waveguide, such as from a user’s finger. This light source and waveguide could also be used to detect an input along an input surface having a one-dimensional extent, such as an input surface configured as a slider button.
These light-based sensors may also include LIDAR systems. Thus they can measure distance or displacement of just a single location on a target object. In the case of a user input surface, detecting a user input at many locations across the user input surface would require a corresponding number of light-based sensor mechanisms. Each detects distance or displacement from a respective single location on a target object.
If Apple is able to put together this technology into their future iPhones and other devices successfully, it will surely bring a huge change for the Apple devices. However, this is still in the patents, Apple may or may not introduce the technology to their devices. Let’s wait to see if Apple makes any official announcement regarding this new patent and technology or not.