BACKGROUND OF THE INVENTION

Modern computing and display technologies have facilitated the development of systems for so called “virtual reality” or “augmented reality” experiences, wherein digitally reproduced images or portions thereof are presented to a viewer in a manner wherein they seem to be, or may be perceived as, real. A virtual reality, or “VR,” scenario typically involves presentation of digital or virtual image information without transparency to other actual real-world visual input; an augmented reality, or “AR,” scenario typically involves presentation of digital or virtual image information as an augmentation to visualization of the actual world around the viewer.

Despite the progress made in these display technologies, there is a need in the art for improved methods and systems related to augmented reality systems.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, an eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane, a second planar waveguide positioned in a second lateral plane adjacent the first lateral plane, and a third planar waveguide positioned in a third lateral plane adjacent the second lateral plane. The first waveguide includes a first diffractive optical element (DOE) coupled thereto and disposed at a lateral position. The first DOE is configured to diffract image light in a first wavelength range centered at a first wavelength. The second waveguide includes a second DOE coupled thereto and disposed at the lateral position. The second DOE is configured to diffract image light in a second wavelength range centered at a second wavelength longer than the first wavelength. The third waveguide includes a third DOE coupled thereto and disposed at the lateral position. The third DOE configured to diffract image light in a third wavelength range centered at a third wavelength longer than the second wavelength. The eyepiece further includes a first optical filter disposed between the first waveguide and the second waveguide at the lateral position, and a second optical filter positioned between the second waveguide and the third waveguide at the lateral position. The first optical filter is configured to have a first transmittance value at the first wavelength range, a second transmittance value at the second wavelength range and the third wavelength range that is greater than the first transmittance value, and a first reflectance value at the first wavelength range that is greater than about 90%. The second optical filter is configured to have a third transmittance value at the first wavelength range and the second wavelength range, a fourth transmittance value at the third wavelength range that is greater than the third transmittance value, and a second reflectance value at the second wavelength range that is greater than about 90%. In some examples, each of the first transmittance value and the third transmittance value may be less than about 10%; and each of the second transmittance value and the fourth transmittance value may be greater than about 90%. In some other examples, each of the first transmittance value and the third transmittance value may be less than about 20%; and each of the second transmittance value and the fourth transmittance value may be greater than about 80%. In some examples, the first optical filter may be configured to have the first transmittance value and the second transmittance value for angles of incidence ranging from about zero degree to about 45 degrees; and the second optical filter may be configured to have the third transmittance value and the fourth transmittance value for angles of incidence ranging from about zero degree to about 45 degrees. In some other examples, the first optical filter may be configured to have the first transmittance value and the second transmittance value for angles of incidence ranging from about zero degree to about 25 degrees; and the second optical filter may be configured to have the third transmittance value and the fourth transmittance value for angles of incidence ranging from about zero degree to about 25 degrees.

According to another embodiment of the present invention, an eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane. The first waveguide has a first lateral region and a second lateral region. The first lateral region is disposed at a lateral position and configured to receive image light incident on a first lateral surface thereof. The image light includes image light in a first wavelength range centered at a first wavelength, image light in a second wavelength range centered at a second wavelength longer than the first wavelength, and image light in a third wavelength range centered at a third wavelength longer than the second wavelength. The eyepiece further includes a first diffractive optical element (DOE) optically coupled to the first lateral region of the first waveguide and configured to diffract image light in the first wavelength range into the first waveguide to be guided toward the second lateral region of the first waveguide. A first portion of the image light is transmitted through the first waveguide. The eyepiece further includes a first optical filter positioned in a second lateral plane adjacent the first lateral plane at the lateral position and configured to receive the first portion of the image light. The first optical filter is further configured to have a first transmittance value for the first wavelength range and a second transmittance value for the second wavelength range and the third wavelength range that is greater than the first transmittance value. The eyepiece further includes a second planar waveguide positioned in a third lateral plane adjacent the second lateral plane. The second waveguide has a first lateral region and a second lateral region. The first region is disposed at the lateral position and configured to receive image light transmitted through the first optical filter and incident at a first lateral surface thereof. The eyepiece further includes a second DOE optically coupled to the first lateral region of the second waveguide and configured to diffract image light in the second wavelength range into the second waveguide to be guided toward the second lateral region of the second waveguide. A second portion of the image light is transmitted through the second waveguide. The eyepiece further includes a second optical filter positioned in a fourth lateral plane adjacent the third lateral plane at the lateral position and configured to receive the second portion of the image light. The second optical filter is configured to have a third transmittance value for the first wavelength range and the second wavelength range and a fourth transmittance value for the third wavelength range that is greater than the third transmittance value. The eyepiece further includes a third planar waveguide positioned at a fifth lateral plane adjacent the fourth lateral plane. The third waveguide has a first lateral region and a second lateral region. The first lateral region is disposed at the lateral position and configured to receive image light transmitted through the second optical filter and incident at a first lateral surface thereof. The eyepiece further includes a third DOE optically coupled to the first lateral region of the third waveguide and configured to diffract image light in the third wavelength range into the third waveguide to be guided toward the second lateral region of the third waveguide.

According to yet another embodiment of the present invention, an eyepiece for projecting image light to an eye of a viewer includes a first planar waveguide. The first waveguide includes a first diffractive optical element (DOE) optically coupled thereto. The first DOE is positioned along an optical path of the image light and configured to couple a portion of the image light in a first wavelength range centered at a first wavelength into the first planar waveguide to be propagated in the first planar waveguide. The eyepiece further includes a first optical filter positioned along the optical path downstream from the first DOE. The first optical filter is configured to attenuate the image light in the first wavelength range incident thereon. The eyepiece further includes a second planar waveguide. The second waveguide includes a second DOE optically coupled thereto. The second DOE is positioned along the optical path downstream from the first optical filter and configured to couple a portion of the image light in a second wavelength range centered at a second wavelength different from the first wavelength into the second planar waveguide to be propagated in the second planar waveguide. The eyepiece further includes a second optical filter coupled to the first planar waveguide. The second optical filter is configured to absorb image light in the second wavelength range propagating in the first planar waveguide.

According to a further embodiment of the present invention, an eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane, a second planar waveguide positioned in a second lateral plane adjacent the first lateral plane, and a third planar waveguide positioned in a third lateral plane adjacent the second lateral plane. The first waveguide includes a first diffractive optical element (DOE) coupled thereto and disposed at a first lateral position. The second waveguide includes a second DOE coupled thereto and disposed at a second lateral position. The third waveguide includes a third DOE coupled thereto and disposed at the second lateral position. The eyepiece further includes an optical filter positioned between the second waveguide and the third waveguide at the second lateral position.

According to some other embodiments of the present invention, an eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane. The first waveguide includes a first incoupling element optically coupled thereto. The first incoupling element is configured to diffract image light in a first wavelength range centered at a first wavelength. The eyepiece further includes a second planar waveguide positioned in a second lateral plane adjacent the first lateral plane. The second waveguide includes a second incoupling element optically coupled thereto. The second incoupling element is configured to diffract image light in a second wavelength range centered at a second wavelength different from the first wavelength. The eyepiece further includes a first optical element positioned between the first waveguide and the second waveguide in lateral alignment with the first incoupling element. The first optical element is configured to reflect image light in the first wavelength range.

