Patent ID: 11892633
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 21:
22. A display apparatus comprising:
an image providing device configured to provide an image;
a combiner configured to combine light containing the image, which is emitted from the image providing device, and light containing an external landscape; and
an eye tracker configured to track a location of a pupil of an observer and measure a size of the pupil of the observer,
wherein the combiner comprises a plurality of volume gratings configured to diffract the light containing the image emitted from the image providing device,
wherein each volume grating of the plurality of volume gratings has a first surface and a second surface facing each other, and
wherein each volume grating of the plurality of volume gratings is configured to diffract light incident on the first surface and transmit therethrough light incident on the second surface without diffraction,
wherein the image providing device is further configured to adjust a beam diameter of light incident on the first surface of each volume grating of the plurality of volume gratings, based on information with respect to the location of the pupil of the observer or information with respect to the size of the pupil of the observer.