Wide angle and high resolution tiled head-mounted display device
A tiled head-mounted display device, comprising: an optical component including a plurality of prisms with free-form surfaces, each prism being a wedge prism comprising a first optical surface, a second optical surface and a third optical surface; and a display component including a plurality of micro-displays, wherein the number of the micro-displays and the number of the prisms with free-form surfaces is identical. The tiled head-mounted display device according to the present invention is compact and light, provides wide field of view and high resolution, especially for the optical tiling head-mounted display device, the exit pupil planes of each display channels are coincident, thus avoiding pupil aberration and keeping exit pupil diameter and eye clearance same as the single ocular. There is no resolution variance throughout the entire field of view, thus preventing extra trapezoid distortion. The tiled head-mounted display device according to the present invention can be readily applicable to augmented environments applications by simply adding an auxiliary free-form lens behind the free-form prism.
1. A tiled head-mounted display device, comprising:
an optical component including a plurality of prisms with free-form surfaces, each prism being a wedge prism comprising a first optical surface, a second optical surface and a third optical surface, each second and third optical surface disposed in opposition to one another across each respective prism; and
a plurality of micro-displays, each micro-display associated and in optical communication with a single respective one of the plurality of prisms with free-form surfaces, and each prism in optical communication with a respective single one of the plurality of micro-displays,
wherein each prism with free-form surfaces and the associated micro-display constitutes a display channel, and a global coordinate system is defined as: a global coordinate origin O is at the exit pupil center; Z-axis is in a direction along the viewing axis of a user's eye; Y-axis is perpendicular to Z-axis and extends right above the eye; X-axis is perpendicular to both Y-axis and Z-axis, constituting a Cartesian coordinate system;
wherein the display channels are tiled in a mosaic pattern with all respective second surfaces adjacent one another to provide a wall of second surfaces and all respective third optical surfaces adjacent one another to provide a wall of third surfaces so that an overall field of view of the tiled device is a summation of individual fields of view of each display channel and the center of an exit pupil of each display channel in the tiled device is located at the exit pupil center at the global coordinate origin O, wherein the first optical surface, the second optical surface and the third optical surface are disposed in a counter-clockwise order relative to X-axis, and wherein the first and second optical surfaces are free-form surfaces.
2. The tiled head-mounted display device of claim 1 , wherein the first optical surface is a transmissive surface, the second optical surface is an at least partially reflective surface, and the third optical surface is a transmissive surface.
3. The tiled head-mounted display device of claim 1 , wherein the head-mounted display device comprises a first display channel, a second display channel and a third display channel rotated about Y-axis of a global coordinate system by a predetermined angle.
4. The tiled head-mounted display device of claim 1 , wherein the tiled head-mounted display has a horizontal field of view of at least 70° and a vertical field of view of at least 50°.
5. The tiled head-mounted display device of claim 1 , wherein the tiled head-mounted display has a horizontal field of view of at least 50° and a vertical field of view of at least 40°.
6. The tiled head-mounted display device of claim 1 , comprising a plurality of auxiliary lenses with free-form surfaces, a respective one of each of the auxiliary lenses associated with a corresponding one of the prisms with free-form surfaces, wherein the second optical surface of each prism with free-form surfaces is a semi-transmissive and a semi-reflective surface.
7. The tiled head-mounted display device of claim 6 , wherein the plurality of auxiliary lenses includes a material with a refractive index N d1 of 1.4<N d1 <1.8.
8. The tiled head-mounted display device of claim 7 , wherein the plurality of auxiliary lenses includes a material with an Abbe number V d1 above 20.
9. The tiled head-mounted display device according to claim 1 , wherein the exit pupil diameter is at least 6 mm.
10. The tiled head-mounted display device according to claim 1 , wherein the eye clearance is at least 15 mm.
11. The tiled head-mounted display device of claim 1 , wherein the tiled head-mounted display has a horizontal field of view of at least 70° and a vertical field of view of at least 30°.