Patent ID: 11861063
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC F  G

Claim 12:
13. A display apparatus comprising:
an image forming device configured to form an image;
an eye-tracking device configured to track an observer's eye and comprising:
an infrared light source configured to emit an infrared illumination light;
a photodetector array comprising a plurality of infrared photodiodes that are arranged in a two-dimensional (2D) manner;
a light guide plate configured to transmit the infrared illumination light emitted from the infrared light source to the observer's eye and transmit the infrared illumination light reflected from the observer's eye to the photodetector array; and
a signal processor configured to determine a displacement of the observer's eye based on a 2D intensity distribution of the infrared illumination light incident on the plurality of infrared photodiodes; and
an image shifter configured to move the image according to an angle of rotation of the observer's eye,

wherein the light guide plate comprises:
a first input/output coupler and a second input/output coupler configured to guide the infrared illumination light to be incident into the light guide plate, to travel inside the light guide plate, and to travel outside the light guide plate;
an input coupler facing the first input/output coupler, the input coupler being configured to guide visible light into the light guide plate; and
an output coupler facing the second input/output coupler, the output coupler being configured to output the visible light traveling inside the light guide plate to an outside of the light guide plate,

wherein the display apparatus further comprises:
a wavelength selective mirror facing the input coupler and the first input/output coupler and configured to combine the infrared illumination light emitted from the infrared light source with the image formed by the image forming device and cause a combination of the infrared illumination light and the image to propagate through a same optical path; and
a beam splitter disposed between the wavelength selective mirror and the light guide plate and configured to transmit the infrared illumination light emitted from the infrared light source to the first input/output coupler and transmit the infrared illumination light received from the first input/output coupler to the photodetector array.