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

Claim 0:
1. An eye-tracking device comprising:
a light source configured to emit an illumination light;
a light guide plate configured to transmit the illumination light emitted from the light source to an observer's eye and transmit the illumination light reflected from the observer's eye in a direction opposite to a propagation direction of the illumination light emitted from the light source;
a photodetector array configured to detect the illumination light reflected from the observer's eye, the photodetector array comprising a plurality of two-dimensionally arranged photodiodes; and
a signal processor configured to determine a displacement of the observer's eye based on a two-dimensional (2D) intensity distribution of the illumination light incident on the plurality of photodiodes,
wherein the light guide plate comprises:
a first input/output coupler and a second input/output coupler configured to guide the 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 eye-tracking device further comprises:
a wavelength selective mirror facing the input coupler and the first input/output coupler and configured to combine the illumination light emitted from the light source with an image formed by an image forming device and cause a combination of the 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 illumination light emitted from the light source to the first input/output coupler and transmit the illumination light received from the first input/output coupler to the photodetector array.