Apple has been granted a patent for a Highly Tunable Foveated Lens System for future Smartglasses and MR Headset
Today, The U.S. Patent and Trademark Office officially published a granted patent for Apple Inc. that relates optical systems, and, more particularly, to devices with highly tunable lenses.
Tunable and Foveated Lens Systems
Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to future Apple glasses and/or a mixed reality headset with highly tunable lenses. Uniquely, the lens system could accommodate multiple users with varying vision impairments such as myopia, hyperopia, presbyopia, astigmatism, higher-order aberrations, and/or other vision defects. This area of technology has been a focus at Apple. In the last year four other such patents have come to light: 01, 02, 03 and 04.
Eyeglasses may be worn by a user and may include one or more adjustable lenses each aligned with a respective one of a user's eyes. For example, a first adjustable lens may align with the user's left eye and a second adjustable lens may align with the user's right eye. Each of the first and second adjustable lenses may include one or more liquid crystal cells or other voltage-modulated optical material. Each liquid crystal cell may include a layer of liquid crystal material interposed between transparent substrates. Control circuitry may apply control signals to an array of electrodes in the liquid crystal cell to adjust a phase profile of the liquid crystal material.
In some arrangements, each adjustable lens may include three or six liquid crystal cells, each having an associated array of electrodes. The electrodes in the liquid crystal cells may be oriented along three different directions. If desired, arrangements with fewer than three or more than three directions may be used.
The adjustable lenses may be foveated such that the liquid crystal within the user's gaze is controlled to exhibit a different optical power than the liquid crystal outside of the user's gaze. The control circuitry may track the user's gaze with a sensor system and may adjust the location of the optically distinct area of the adjustable lenses so that it remains aligned with the user's gaze.
Such optical powers can be helpful to users exhibiting presbyopia, a condition whereby the user's eyes are no longer able to adjust their focal power to bring into focus objects at significantly different distances.
Glasses able to compute the deficiency in the user's accommodation can correct for this deficiency through applying distinct optical power. Limiting the spatial extent of the differing optical power can reduce disorienting visual sensations caused by changes in magnification applied to images of the world as seen through the glasses.
Further, a user's eyes may exhibit static or focus-dependent optical defects known as "higher-order aberrations" that are not in general correctable by any static prescription, but can be partially or completely correctable by the portion of variable phase that follows a user's gaze.
Apple's patent FIG. 1 below covers system #10 may include a head-mounted device such as eyeglasses #14. Glasses may include one or more optical systems such as adjustable lens components #22 mounted in a support structure such as support structure #12.
More specifically, adjustable lenses #22 may be corrective lenses that correct for vision defects. For example, eyes #16 may have vision defects such as myopia, hyperopia, presbyopia, astigmatism, higher-order aberrations, and/or other vision defects. Corrective lenses such as lenses #22 may be configured to correct for these vision defects.
More importantly, the lenses may be adjustable to accommodate users with different vision defects and/or to accommodate different focal ranges. For example, lenses #22 may have a first set of optical characteristics for a first user having a first prescription and a second set of optical characteristics for a second user having a second prescription.
The glasses may be used purely for vision correction (e.g., glasses #14 may be a pair of spectacles) or the glasses may include displays that display virtual reality or augmented reality content.
In virtual reality or augmented reality systems, adjustable lens components #22 may be used to move content between focal planes from the perspective of the user.
Apple's patent FIG. 3 below FIG. 3 is a cross-sectional side view of an illustrative liquid crystal module having first and second liquid crystal layers with antiparallel liquid crystal alignment orientations; FIG. 6 below is a top view of an illustrative adjustable lens component having arrays of electrodes that extend along first and second directions; FIG. 7 is a top view of an illustrative adjustable lens component having arrays of electrodes that extend along first, second, and third directions; FIG. 8 is an exploded perspective view of an illustrative adjustable lens having first, second, and third liquid crystal cells, each with an associated orientation of electrodes; FIG. 9 is an exploded perspective view of an illustrative adjustable lens having first, second, and third liquid crystal modules, each with an associated orientation of electrodes, in accordance with an embodiment.
Apple's patent FIG. 10 below is a perspective view of a foveated adjustable lens system; FIG. 11 is a top view of an illustrative adjustable lens system having a subset of electrodes driven such as to create a lens patch with variable optical power that aligns with a user's gaze.
For more details, review Apple's granted patent 11,221,488. Two of the inventors listed on this patent includes Alexander Miles (Optical Scientist) and Yu Horie (Senior Research Scientist).