Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to a gyroscopic precession engine for their future HMDs in the form of an Extended Reality Headset or future smartglasses. A gyroscopic precession engine is capable of delivering superior immersive media content for movies and games.

In Apple's patent background they note that Extended Reality (XR), which includes Virtual Reality (VR) and Augmented Reality (AR) mediums enable consumers to immerse themselves in content. With increased consumer interest there is a greater need for immersive content to be created for XR. Haptic engines are an important aspect of XR, as they impart physical sensations on a user's body that enhances the user's immersive experience. Typical haptic engines found in smart phones and other mobile devices, however, only provide vibrations along a single axis. Haptic engines that produce vibrations are useful for notification applications, but cannot provide a continuous torque or force on wearable devices, such as a head-mounted display (HMD). 

Gyroscopic Precession Engine for HMD 

Apple's invention covers a gyroscopic precession engine for wearable devices.

Apple's granted patent provides the following advantages. A gyroscopic precession engine provides a continuous torque/force sensation along multiple degrees of freedom. The gyroscopic precession engine can be mounted to, or embedded in, a head-mounted display (HMD) or other wearable device to provide spatial guidance in VR and AR applications by, for example, guiding the user's head in a particular direction in sync with the immersive visual content viewed by the user.

The gyroscopic precession engine also improves immersive media content for movies and games by providing a continuous torque/force on a user's head/neck or other body part that is synced with visual content, such as creating a sensation of air wave pressure (e.g., from an explosion scene), creating a sensation of centrifugal force (e.g., a bumpy roller coaster ride or car racing), head/neck/hand/wrist exercising (e.g., providing a counter torque to the user's motion), ergo correction (e.g., notify or guide the user to a fix bad sitting or standing posture) and providing reaction force feedback in VR applications (e.g., boxing an object and feeling a reaction force on the hand/wrist).

Technically, Apple's granted patent covers a wearable device that comprises: a support structure including at least one attachment mechanism for attaching the support structure to a human body part; at least one gyroscopic precession engine coupled to the support structure, the gyroscopic precession engine, comprising: a first motor configured to rotate a wheel mount at a first angular velocity; at least one wheel rotatably coupled to the wheel mount and configured to spin at a second angular velocity; a second motor configured to spin the wheel at the second angular velocity different than the first angular velocity; and at least one motor controller coupled to the first motor and the second motor, the at least one motor controller configured to rotate the wheel mount at the first angular velocity and spin the wheel at the second angular velocity, wherein the wheel mount is configured, when spinning, to move in free space in response to a torque produced by a product of the first angular velocity of the wheel mount and the second angular velocity and a moment of inertia of the wheel, and wherein the wearable device moves in response to a force produced by the torque.

Apple's patent FIG. 1A below is a side view of the gyroscopic precession engine #100 and FIG. 1B is a perspective view of the gyroscopic precession engine. The gyroscopic precession engine includes servo motor #102, rotatable wheel mount #103, spinning wheel #104 and wheel motor #105. The gyroscopic precession engine can be attached to wearable device, such as an HMD.

Apple further notes that the wearable device (#100) can be worn on the head or as part of a helmet, headband or smart glasses that has a small display optic in front of one or both of the user's eyes. The wearable device can be used in a variety of applications, including but not limited to: spatial guidance (e.g., for generating a continuous force/torque to guide the user's head as a guiding force), sound enhancement (e.g., to improve the feeling of sound in gaming or a movie, such as air wave pressure feeling from an explosion in a scene), haptic notification (e.g., provide a pulsing force to indicate an incoming communication or other force feedback), gaming (e.g., providing sensations, such bumpy ride on a rollercoaster, car-racing centrifugal force, etc.), head/neck/hand/wrist exercise (e.g., providing a counter torque), ergo correction (e.g., notify and guide user to fix bad sitting or standing postures during long hour usage), handhold input device for force feedback (e.g., object interaction in VR content, such as boxing an object with reaction force feedback), aviation, engineering, medicine, or any other application that could benefit from the sensation provided by continuous force/torque.

In an embodiment, the wearable device can be a VR headset that includes an inertial measurement unit (IMU) and a transparent wearable display that reflects projected images.

Apple's patent FIG. 1C below illustrates a head-centered coordinate system with yaw, pitch and roll axes: By adding another two precession engines, the design can provide torque/force sensation along roll, yaw and pitch axes; FIGS. 2A-2C illustrate various configurations for torque direction in a head-centered coordinate system are shown.

Apple's patent FIG. 3 above is a flow diagram of a process that uses a gyroscopic precession engine to provide continuous torque/force.

Apple's granted patent '1398 was filed for in 2021.