Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to a new self-mixing interferometry (SMI) sensor-based gesture input system. The majority of the invention relates to a smart ring being used alone or in pairs, with or without an Apple Pencil for AR, VR and MR applications.

Gesture Input System using a Smart Ring

Apple's latest ring invention covers systems, devices, methods, apparatus and operation of an SMI-based gesture input system that includes one or more self-mixing interferometry (SMI) sensors.

In one instance, the SMI sensor(s) may be used to determine a relationship between a ring and a handheld device, such as an Apple Pencil.  

More specifically, the patent relates to the configuration and operation of SMI-based gesture input systems--i.e., systems that can identify gestures made by a user using signals received from one or more SMI sensors.

An SMI sensor can be used to optically measure the relative motion (displacement) between the SMI sensor and a target (e.g., a surface or object), with sub-wavelength resolution.

When displacement measurements are associated with measurement times, the velocity of the target may also be measured. Furthermore, by modulating the SMI sensor with a known wavelength modulation (e.g., a triangular modulation), the absolute distance from the SMI sensor to the target may be measured.

In augmented reality (AR), virtual reality (VR), and mixed reality (MR) applications, as well as other applications, it can be useful to track a user's finger movement(s) and/or identify a user's gestures (e.g., gestures made with one or more fingers, a hand, an arm, etc.).

In some applications, it is useful for a user to be able to provide input to a system by interacting with a surface (e.g., making a gesture on any random surface, such as a tabletop, wall, or piece of paper), or by making a gesture in free space. 

With three or more SMI sensors, movements in x, y, and z directions may be tracked. Motion tracking with six degrees of freedom may also be tracked with three or more SMI sensors.

Apple's patent FIG. 1 below shows an example SMI-based gesture input system that includes a wearable device such as a smart ring (seen in-part); Apple's patent FIG. 7 shows smart rings placed on two of the user's fingers; FIG. 4 shows a wearable device having a set of SMI sensors, from which a processor of the device may select a subset of SMI sensors to determine a relationship between the wearable device and a surface.  

Apple further notes that FIG. 7 illustrates dual rings used in context with Mixed Reality applications. Finger rings worn on a user's thumb and index finger, for example, may be used to identify gestures such as a pinch, zoom, rotate, and so on.

Apple's patent FIG. 6 shows an example of the system described with reference to FIG. 5 (further below), in which the wearable device is a finger ring and the object is an Apple Pencil (or digital marker or paintbrush). These figures are also in context with AR, VR and MR applications.

Apple's patent FIGS. 9C and 9D illustrate different beam-shaping or beam-steering optics that may be used with any of the SMI sensors; FIG. 13 shows an example method of identifying a type of gesture.

For more details, review Apple's granted patent 11,409,365.