Today the U.S. Patent and Trademark Office officially granted Apple several patents. One relates to a head mounted display (HMD) device's head adjustment system. The system will allow users to adjust the fit of their HMD sitting on their head for a perfect, snug fit. A second patent relates to optical systems with adjustable lenses and a third patent covers improved calibration for on-device eye tracking.

HMD – Head Adjustment System

Existing head-mounted displays can be adjusted for circumferential fit using features such headbands made from elastic materials and temple-located adjustment mechanisms that change a length of a non-elastic headband between a variety of predetermined lengths.

However, these adjustment options do not address differences in facial features, such as different inter-pupillary distances (IPD) among users.

Apple's invention covers head-mounted display and adjustment mechanisms for optical components within the head-mounted display.

A head-mounted display includes an optical assembly and an actuator. The actuator includes a movement mechanism configured to adjust a position of an optical component within the optical assembly, a locking-release mechanism configured to modify operation of the movement mechanism upon detection of a dynamic event, and a dampening mechanism configured to control positional changes of the optical component during the dynamic event.

A method includes detecting, using a sensor in a head-mounted display, a start of a dynamic event. In accordance with detection of the start of the dynamic event and using a locking-release mechanism, the method includes modifying operation of a movement mechanism.

Apple's patent FIG. 1 below is a top view of a head-mounted display; FIG. 6A is a detail view of a mechanical dampening mechanism for an actuator; Apple's patent FIG. 6B above is a detail view of another mechanical dampening mechanism for an actuator. 

More specifically, Apple's patent FIG. 6A illustrates the mechanical dampening mechanism can include one or more cables 626 and 628 (two are shown in solid and dotted line) disposed proximate to ends of the lead screw (#604) and the guide rail (#606). In this embodiment, the cables can either wind or unwind during a dynamic event, serving to slow or counteract motion of the nut assembly (#608) to avoid having the nut assembly impact the ends of the lead screw and guide rail (#606) when sliding.

Apple's patent FIG. 7 below is a flowchart depicting a process of operation for an actuator similar to the actuators.

For more details, review Apple's granted patent 11,106,034.

Optical Systems with Adjustable Lenses

Apple's second HMD granted patent generally relates to optical systems and, more particularly, to optical systems with adjustable lenses.

Cameras, display projectors, and other optical systems have lenses. It may sometimes be desirable to adjust a lens. For example, it may be desirable to adjust the focal length of a zoom lens or it may be desirable to focus a lens. Many optical systems are provided with manually adjustable lens mounts that allow lens adjustments such as focal length adjustments to be made. Motors and other electrically controllable elements may also be used in making lens adjustments.

Optical systems with adjustable lenses such as these may be bulky and may respond more slowly than desired to control commands. Apple's granted patent 11,105,963 provides a solution with tunable lenses with focal lengths that are adjusted by control circuitry.

The properties of the lens #14 of patent FIG. 2 below may be adjusted to adjust the appearance of a virtual image. For example, the focal length of the lens may be adjusted. In systems such as head-up displays (e.g., augmented reality or virtual reality displays), the focal length of the lens may be adjusted to reduce or eliminate vergence-accommodation mismatch.

For more details, review Apple's granted patent here.

On-the-Fly Calibration for improved on-device Eye Tracking

Apple's third HMD granted patent generally relates to the field of eye tracking, and more particularly to on-the-fly calibration for improved on-device eye tracking.

Eye tracking and gaze estimation on mobile devices provide users another dimension of input. Eye tracking also enables hands-free interaction. Under some circumstances, gaze input can be more attractive than other modalities, such as touch (which may be limited, for example while cooking or driving), and voice (not suitable for noisy/crowded situations). Apple's granted patent 11,106,280 covers a method for improved calibration for on-device eye tracking which you could review here for more details.

Apple's patent FIG. 2 below shows, in flowchart form, a method for on-the-fly calibration of eye tracking on an electronic device; FIG. 4 shows an example user interface for on-the-fly calibration.