9to5Mac's writer Ben Lovejoy absolutely loves Meta's photo glasses that's working towards being full pledged smartglasses one day. Lovejoy's report is extensive and worth a read if photo glasses is something that you've been thinking of purchasing but haven't pulled the trigger yet. Another positive review could be found on ZDNet.

Without a doubt, Meta is striving to make the leap from photo-glasses to truly advanced smartglasses ahead of Apple that is slow to adopt new technologies. Smartglasses will be another device to drive Meta's AI technology which aims to one day replace smartphones like the iPhone. This week another three smartglasses patents were published from both the U.S. and European Patent Offices.

Holographic Optical Element View Finder

Meta's patent covers systems, methods, devices, and computer program products utilizing holographic optical elements (HOEs) and producing observable virtual images. Various examples may include at least one illumination source emitting light, and a transparent combining optic comprising a holographic optical element. The light emitted from the illumination source may illuminate the transparent combining optic, including the holographic optical element, and the transparent combining optic may diffract the light to generate an observable virtual image. The observable virtual image may be positioned to overlay a scene viewable through the transparent combining optic. In some examples, the transparent combining optic, including the HOE, may diffract the light to project the observable virtual image on a display.

In an example, a system may be provided. The system may include a transparent combining optic including a holographic optical element. The holographic optical element may be configured to diffract light emitted from an illumination source illuminating the holographic optical element. The holographic optical element may also be configured to diffract the light to generate an observable virtual image positioned to overlay a scene viewable through the transparent combining optic.

The display which may present the observable virtual image, caused by the holographic optical element (HOE) diffracting the light and projecting the observable virtual image, may be included on a wearable system, such as a head-mounted display system. In some examples of the present disclosure, the head-mounted display system is at least one of a headset, glasses, helmet, visor, gaming device, or a smart device. The display may form part or all of one or more lenses, such as one or more lenses on a glasses frame. As such, the observable virtual image projected by the display may provide a virtual image that may be observed by a user wearing the glasses. In some examples, a plurality of observable virtual images may be provided on the display.

One or more images may be selectable, and include, for example, a time, a letter, a number, a shape, or an icon. At least one of the observable virtual images may be selectable. For example, when used with an eye tracking system, information indicative of a user focusing on or looking at the observable virtual image may cause one or more actions to be taken. Such action may include, for example, taking an image of a scene captured by one or more cameras associated with the system, selecting an icon (e.g., opening up an application or feature associated with the icon, etc.), and/or the like.

 Various systems, methods, devices, computer program products and examples of the present disclosure may include at least one camera capturing a scene, wherein an observable virtual image is associated with and/or highlights/represents or projects a section of the scene captured by the camera (e.g., a border indicating the region of capture). An eye tracking system may track at least one eye viewing the scene, may determine a region of the scene corresponding to the tracked eye movement, and may update the observable virtual image to highlight/represent and/or project the region of the scene. The region may then be captured in a photograph/image and/or a video.

Meta's patent FIG. 1A below illustrates an example implementation of HOE-based system in use with smartglasses.

You could dive into the details of patent application 20240288694 here.

Other recent Meta Patents for future Smartglasses

01: Wearable Device with Corrective Lens having a Diffractive Surface (Sept. 4)

02: Pixel Sensor using a Dual Pixel Array (Euro patent)