摘要 |
A situation awareness viewing device, typically in the form of a head-mounted display device, includes a polarizing beam splitter made of a cube of a material transparent to light and having an index of refraction greater than 1, and a wire grid polarizer lying within the cube on a cube-diagonal plane extending between two diagonally opposed edges of the cube. The polarizing beam splitter has a first optical axis extending from a first face of the cube toward an opposing second face of the cube and lying at an angle of 45 degrees to the cube-diagonal plane, and a second optical axis extending from a third face of the cube toward an opposing fourth face of the cube and lying at an angle of 45 degrees to the cube-diagonal plane, the second optical axis being perpendicular to the first optical axis. The device further includes an external polarizer external to the cube on the first optical axis and disposed to intercept light incident upon the first face along the first optical axis, an image source external to the cube and disposed to send a display image incident upon the third face along the second optical axis, a quarter-wave plate external to the cube and disposed to intercept a beam of light traveling along the second optical axis and passing out of the cube through the fourth face, and a mirror external to the cube and disposed to reflect light passing through the quarter-wave plate back through the quarter-wave plate and to the fourth face.
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