Substrate-guide optical device

Abstract

An optical device, including a light waves-transmitting substrate has two major surfaces and edges, optical means for coupling light into the substrate by total internal reflection, and a plurality of partially reflecting surfaces (22a, 22b) carried by the substrate. The partially reflecting surfaces (22a, 22b) are parallel to each other and are not parallel to any of the edges of the substrate, one or more of the partially reflecting surfaces (22a, 22b) being an anisotropic surface. The optical device has dual operational modes in see-through configuration. In a first mode, light waves are projected from a display source through the substrate to an eye of a viewer. In a second mode, the display source is shut off and only an external scene is viewable through the substrate.

1 . An optical device, comprising:
 a light waves-transmitting substrate having a plurality of surfaces including at least a first major external surface and a second major external surface, at least one of the first or second major external surfaces being coated with a coating that compensates for non-uniformity of the light-waves transmitting substrate;   a coupling-in optical arrangement for coupling light waves into the light-waves transmitting substrate by total internal reflection; and   a coupling-out optical arrangement for coupling light waves out of the light-transmitting substrate.   
     
     
         2 . The optical device of  claim 1 , wherein the first and second major external surfaces are parallel to each other, and wherein the plurality of surfaces of the light-waves transmitting substrate further includes at least one slanted edge oriented at an oblique angle with respect to the first and second major external surfaces. 
     
     
         3 . The optical device of  claim 2 , wherein the coupling-in optical arrangement is optically attached to the at least one slanted edge. 
     
     
         4 . The optical device of  claim 1 , further including a blank plate optically attached to one of the first or second major external surfaces, and wherein the blank plate and the coupling-out optical arrangement define an active area of the light-waves transmitting substrate. 
     
     
         5 . The optical device of  claim 1 , wherein the coupling-out optical arrangement is carried by the light-waves transmitting substrate. 
     
     
         6 . The optical device of  claim 1 , wherein the coupling-out optical arrangement includes at least one partially reflecting surface. 
     
     
         7 . The optical device of  claim 6 , wherein the at least one partially reflecting surface includes a plurality of partially reflecting surfaces, and wherein at least two partially reflecting surfaces of the plurality of partially reflecting surfaces have different respective reflectivity. 
     
     
         8 . The optical device of  claim 7 , wherein the non-uniformity of the light-waves transmitting substrate is caused by the different reflectivity of the at least two partially reflecting surfaces of the plurality of the partially reflecting surfaces. 
     
     
         9 . The optical device of  claim 6 , wherein the at least one partially reflecting surface is an anisotropic partially reflecting surface. 
     
     
         10 . The optical device of  claim 6 , wherein the at least one partially reflecting surface is coated with a polarization sensitive coating. 
     
     
         11 . The optical device of  claim 6 , wherein the at least one partially reflecting surface is coated with an angular sensitive thin film coating. 
     
     
         12 . The optical device of  claim 6 , wherein the light-waves transmitting substrate is composed of a plurality of substantially transparent plates, and wherein the at least one partially reflecting surface is formed by coating at least one surface of at least one of the transparent plates with a partially reflecting coating. 
     
     
         13 . The optical device of  claim 1 , wherein the coupling-out optical arrangement couples light waves out of the light-waves transmitting substrate through the first major external surface, and wherein the coating that compensates for non-uniformity of the light-waves transmitting substrate is applied to the second major external surface. 
     
     
         14 . The optical device of  claim 1 , wherein the light-waves transmitting substrate is composed of a plurality of substantially transparent plates. 
     
     
         15 . An optical device, comprising:
 a light waves-transmitting substrate having a plurality of surfaces including at least a first major external surface and a second major external surface;   a coating deposited on at least one of the first or second major external surfaces, the coating compensating for non-uniformity of the light-waves transmitting substrate;   a coupling-in optical arrangement for coupling light waves into the light-waves transmitting substrate by total internal reflection; and   a coupling-out optical arrangement for coupling light waves out of the light-transmitting substrate.   
     
     
         16 . The optical device of  claim 15 , wherein the coupling-out optical arrangement includes at least one partially reflecting surface. 
     
     
         17 . The optical device of  claim 16 , wherein the at least one partially reflecting surface includes a plurality of partially reflecting surfaces, and wherein at least two partially reflecting surfaces of the plurality of partially reflecting surfaces have different respective reflectivity. 
     
     
         18 . The optical device of  claim 17 , wherein the non-uniformity of the light-waves transmitting substrate is caused by the different reflectivity of the at least two partially reflecting surfaces of the plurality of the partially reflecting surfaces. 
     
     
         19 . The optical device of  claim 16 , wherein the at least one partially reflecting surface is an anisotropic partially reflecting surface. 
     
     
         20 . The optical device of  claim 16 , wherein the at least one partially reflecting surface is coated with a polarization sensitive coating. 
     
     
         21 . The optical device of  claim 16 , wherein the at least one partially reflecting surface is coated with an angular sensitive thin film coating. 
     
     
         22 . The optical device of  claim 15 , wherein the coupling-out optical arrangement couples light waves out of the light-waves transmitting substrate through the first major external surface, and wherein the coating is deposited on the second major external surface.