Angle selective filter for near eye displays

Abstract

One embodiment sets forth a near eye display (NED). The NED includes an electronic display configured to output image light to an optical element. The optical element is configured to receive the image light, direct the image light, and form an image at the eye. The NED also includes an angle selective filter having a curved surface. The angle selective filter is configured to filter out light beams of light exiting the optical element and having an angle of incidence on the curved surface larger than a cut-off angle of incidence.

What is claimed is: 
     
         1 . A near eye display (NED) comprising:
 an electronic display configured to output image light;   an optical element configured to direct a plurality of light beams associated with the image light to an eye-box; and   an angle selective filter comprising a curved surface, the angle selective filter configured to filter out one or more light beams of the plurality of light beams, each of the one or more light beams having an angle of incidence on the curved surface that is larger than a first cut-off angle of incidence.   
     
     
         2 . The NED of  claim 1 , wherein the curved surface comprises a spherical surface. 
     
     
         3 . The NED of  claim 2 , wherein a center of the spherical surface corresponds to a center of rotation of an eye. 
     
     
         4 . The NED of  claim 1 , wherein, for each point on the curved surface, a tangent plane of the point is configured to be normal to an optical axis of an eye when the optical axis of the eye aligns with the point. 
     
     
         5 . The NED of  claim 1 , wherein the angle selective filter comprises a thin film multilayer filter. 
     
     
         6 . The NED of  claim 1 , wherein the angle selective filter comprises a set of louvers arranged concentrically. 
     
     
         7 . The NED of  claim 1 , wherein the one or more light beams include at least one stray light beam. 
     
     
         8 . The NED of  claim 1 , wherein the first cut-off angle of incidence is between a range comprising 45-55 degrees. 
     
     
         9 . The NED of  claim 1 , wherein the angle selective filter is disposed between the optical element and an exit pupil of the NED. 
     
     
         10 . The NED of  claim 1 , wherein the first cut-off angle of incidence corresponds to a visual field of an eye of a user of the NED. 
     
     
         11 . The NED of  claim 1 , further comprising an eye tracking system, the eye tracking system comprises a light source in the near infrared wavelength range, wherein the angle selective filter is further configured to allow a light beam in the near infrared wavelength range with an angle of incidence on the curved surface larger than the first cut-off angle of incidence. 
     
     
         12 . The NED of  claim 1 , wherein a center of the curved surface is adjustable and determined based on a measurement from the eye tracking system. 
     
     
         13 . A near eye display (NED) comprising:
 an electronic display configured to output image light;   a Fresnel lens configured to direct a plurality of light beams associated with the image light to an eye-box, wherein the plurality of light beams exiting the Fresnel lens includes one or more stray light beams; and   an angle selective filter comprising a curved surface, the angle selective filter configured to filter out at least one of the one or more stray light beams, the at least one of the one or more stray light beams having an angle of incidence on the curved surface that is larger than a first cut-off angle of incidence.   
     
     
         14 . The NED of  claim 13 , wherein the curved surface comprises a spherical surface. 
     
     
         15 . The NED of  claim 14 , wherein a center of the spherical surface corresponds to a center of rotation of an eye. 
     
     
         16 . The NED of  claim 13 , wherein, for each point on the curved surface, a tangent plane of the point is configured to be normal to an optical axis of an eye when the optical axis of the eye aligns with the point. 
     
     
         17 . The NED of  claim 13 , wherein the angle selective filter is disposed between the Fresnel lens and an exit pupil of the NED. 
     
     
         18 . A method comprising:
 receiving, from an electronic display, image light associated with a content scene;   filtering out, by an angle selective filter, one or more light beams of the image light having an angle of incidence larger than a first cut-off angle of incidence; and   forming an image of the content scene based on filtered light beams exiting the angle selective filter.   
     
     
         19 . The method of  claim 18 , wherein the angle selective filter comprises a spherical surface, and a center of the spherical surface corresponds to a center of rotation of an eye. 
     
     
         20 . The method of  claim 18 , wherein, for each point on a curved surface of the angle selective filter, a tangent plane of the point is configured to be normal to an optical axis of an eye when the optical axis of the eye aligns with the point.