Apple has been granted a patent (number 10,955,677) for a“scene camera” that hints that the rumored“Apple Glasses” — an augmented reality/virtual reality/mixed reality head-mounted display (HMD) —may use holograms to help make wearers feel as if they’re physically in an AR/VR/MR environment.
In the patent data, the tech giant notes that Various embodiments of a scene camera for a mixed reality (MR) direct retinal projector system would include a scene camera that captures images of the real-world scene in front of the user. The images could be analyzed to locate edges and objects in the scene. They may also be analyzed to determine depth information for the scene.
The information obtained from the analysis could be used to place virtual content in appropriate locations in the MR view provided by the Apple Glasses’ direct retinal projector system. To achieve a more accurate representation of the perspective of the user, the scene camera is located on the side of the MR headset and facing the inside surface of the lens.
The lens includes a holographic medium recorded with one or more transmission holograms that diffract a portion of the light from the scene that is directed to the user’s eye to the scene camera. In this way, the scene camera captures images of the environment from substantially the same perspective as the user’s eye.
Apple says that, to stop unwanted direct light from reaching the scene camera, a band-pass filter, tuned to the transmission hologram wavelength, may be used to block all direct view wavelengths other than the transmission hologram operating wavelength. In addition, a holographic medium may be applied to an outer surface of the lens and recorded with reflection holograms tuned to the same wavelength as the transmission holograms.
The reflection holograms may reflect the light within that wavelength at direct view angles (i.e. direct light from the scene to the scene camera). The combination of the band-pass filter and reflection holograms would block the unwanted direct light while still allowing the wavelength of light diffracted by the transmission holograms to reach the photosensor of the scene camera unhindered. The reflection holograms may also prevent the portion of the direct light to the scene camera corresponding to the wavelength of the transmission holograms from being diffracted to the user’s eye by the transmission holograms.
