主权项 |
1. A see-through head mounted display (HMD) optical system comprising:
a display device; a collimation lens that parallelizes image lights emitted from the display device; a first wedge prism comprising a vertical surface, an inclined surface, a horizontal surface which forms a bottom of the first wedge prism, and two parallel surfaces which form side surfaces of the first wedge prism, the vertical surface configured to receive the parallelized image lights incident from the collimation lens; a second wedge prism comprising a horizontal surface which faces the first horizontal surface of the first wedge prism, an inclined surface, two parallel surfaces which form side surfaces of the second wedge prism, and a vertical surface; and a third wedge prism comprising an inclined surface, a first horizontal surface which forms a bottom of the third wedge prism, and two parallel surfaces which form side surfaces of the third wedge prism, and a vertical surface, the second wedge prism and the third wedge prism being in inverse shape to each other, wherein the first wedge prism comprises a first enlargement unit for enlarging an image in a horizontal direction, the image which having been passed through the vertical surface of the first wedge prism incident from the collimation lens, the second wedge prism comprises a second enlargement unit at the inclined surface of the second wedge prism for enlarging an image incident from the horizontal surface of the first wedge prism in a vertical direction, wherein an inclination angle corresponding to the inclined surface of the first wedge prism and an inclination angle corresponding to the inclined surface of the second wedge prism is the same inclination angle, and the inclined surface of the third wedge prism and the inclined surface of the second wedge prism are obliquely configured in parallel and symmetrically facing each other, and wherein a ratio between the horizontal enlargement corresponding to the first wedge prism and the vertical enlargement corresponding to the second wedge prism is the same according to the configuration of the same inclination angle with respect to the inclined surfaces corresponding to the first wedge prism and the second wedge prism, and an image distortion is reduced due to the same inclination angle and same ratio of image enlargement in the horizontal direction only by the first wedge prism and image enlargement in the vertical direction only by the second wedge prism. |