Compact near-eye display optics for higher optical performance
Systems and methods are described for receiving image content from an emissive display toward a first filter stack, the first filter stack adapted to be oriented in a first direction from an optical axis of a first lens, and toward the first lens, transmitting the image content through a curved lens parallel to the optical axis of the first lens, wherein the curved lens transmits a portion of the image content to at least one optical element and to a second filter stack, the second filter stack being adapted to be oriented in a second direction from the optical axis of the first lens, and receiving the portion from the second filter stack and providing at least some of the portion to the first lens for viewing by a user.
1. A method comprising:
receiving image content from an emissive display toward a first filter stack, the first filter stack being oriented in a first direction from an optical axis of a first lens, and toward the first lens;
transmitting the image content through a curved lens having an optical axis that is parallel to the optical axis of the first lens, wherein the curved lens transmits a portion of the image content to at least one optical element and to a second filter stack, the second filter stack being oriented in a second direction from the optical axis of the first lens, the first direction corresponding to a non-zero tilt of a normal direction of the first filter stack to a first angle with the optical axis, and the second direction corresponding to a non-zero tilt of a normal direction of the second filter stack to a second angle with the optical axis, and wherein the first angle is larger than the second angle; and
receiving the portion from the second filter stack and providing at least some of the portion to the first lens,
wherein the portion changes polarization handedness from right hand circularly polarized to left hand circularly polarized upon passing through the curved lens and the at least one optical element.
2. The method of claim 1 , wherein:
the first angle is about 5 to about 13 degrees off of a vertical offset from the optical axis of the first lens and toward the first lens; and
the second angle is about 5 degrees off of the vertical offset from the optical axis of the first lens.
3. The method of claim 1 , wherein the first filter stack is parallel to the emissive display.
4. The method of claim 1 , wherein the curved lens is composed of plastic and coated with a beam splitter layer.
5. The method of claim 4 , wherein the beam splitter layer includes positive mirror surface configured to resolve display pixels.
6. The method of claim 1 , wherein the at least one optical element comprises two or more optical lenses adapted to reduce optical aberrations.
7. The method of claim 1 , wherein:
the first filter stack is a first standalone assembly that includes a first linear polarizer coupled to a first quarter wave plate;
the second filter stack is a second standalone assembly that includes a second quarter wave plate coupled to a polarizing beam splitter that is coupled to a second linear polarizer; and
the curved lens includes a lens with a beam splitter coating, the curved lens being disposed between the first stand alone assembly and the second standalone assembly.
8. A system comprising:
a first standalone assembly that includes a first linear polarizer coupled to a first quarter wave plate;
a second standalone assembly that includes a second quarter wave plate coupled to a polarizing beam splitter that is coupled to a second linear polarizer adjacent to a non-curved lens; and
a curved lens with a beam splitter coating, the curved lens being disposed between the first stand alone assembly and the second standalone assembly,
wherein the first standalone assembly is oriented in a first direction, the second standalone assembly is oriented in a second direction, the first direction corresponding to a non-zero tilt of a normal direction of the first standalone assembly to a first angle with an optical axis of the non-curved lens, and the second direction corresponding to a non-zero tilt of a normal direction of the second standalone assembly to a second angle with the optical axis of the non-curved lens, and wherein the first angle is larger than the second angle.
9. The system of claim 8 , wherein the beam splitter coating includes a positive mirror surface configured to resolve display pixels.
10. The system of claim 8 , wherein the system further comprises at least one optical element including two or more optical lenses adapted to reduce optical aberrations.
11. The system of claim 8 , wherein the system further includes at least one positive refractive element to balance a field of curvature for the system.
12. The system of claim 8 , wherein the curved lens is non-rotationally symmetrical.
13. A head-mounted display housing comprising:
at least one optical assembly including a curved beam splitter device disposed between a first filter stack and a second filter stack;
an image projecting device adapted to be seated at a plurality of angles within the head-mounted display housing; and
at least one lens; and
wherein the first filter stack is oriented in a first direction, the second filter stack is oriented in a second direction, the first direction corresponding to a non-zero tilt of a normal direction of the first filter stack to a first angle with an optical axis of the at least one lens, and the second direction corresponding to a non-zero tilt of a normal direction of the second filter stack to a second angle with the optical axis of the at least one lens, the first angle being larger than the second angle.
14. The head-mounted display housing of claim 13 , wherein the image projecting device is seated at a tilt angle selected based on the first angle or the second angle.
15. The head-mounted display housing of claim 14 , wherein the tilt angle comprises more than 5 degrees and less than 25 degrees of a vertical offset from the optical axis of the at least one lens.
16. The head-mounted display housing of claim 13 , wherein a tilt of the first filter stack or the second filter stack results in modifying a field of view associated with the head-mounted display housing, the modification including moving image artifacts outside of the field of view.
17. The head-mounted display housing of claim 13 , further comprising a plurality of optical elements disposed between the first filter stack and the second filter stack, the plurality of optical elements configured to decrease optical aberrations.
18. The head-mounted display housing of claim 13 , wherein the at least one lens provides a focal length of about 13 millimeters to about 20 millimeters within the head-mounted display housing.
19. The head-mounted display housing of claim 13 , wherein the first filter stack includes a first linear polarizer coupled to a first quarter wave plate and the second filter stack includes a second quarter wave plate coupled to a polarizing beam splitter that is coupled to a second linear polarizer.
20. The head-mounted display housing of claim 13 , wherein the head-mounted display housing includes two optical assemblies, each configured to provide image content to the at least one lens in corresponding left and right eyepieces associated with the head-mounted display housing.