Degrees of freedom for diffraction elements in wave expander
First Claim
1. A near-eye display device comprising:
- an imager to generate an image based on light from a light source; and
a waveguide to input a light wave representing the image received from the imager and to output the light wave representing the image toward an optical receptor of a user of the near-eye display device, the waveguide including a plurality of diffractive optical elements (DOEs) in a common light path from an input of the waveguide to an output of the waveguide, the DOEs including a plurality of periodic diffraction patterns, each of the periodic diffraction patterns being represented by a corresponding diffraction pattern vector, the periodic diffraction patterns being such that a vector summation of the diffraction pattern vectors of the plurality of DOEs equals zero,wherein the plurality of DOEs include;
a first DOE to receive the light wave incident upon the first DOE in a first direction and redirect the light wave;
a second DOE to receive the light wave from the first DOE and expand the light wave in a second direction, the light wave being reflected by a periodic diffraction pattern of the second DOE for an even integer number of times; and
a third DOE to further expand the light wave in a third direction and redirect the expanded light wave toward the optical receptor of the user in the first direction.
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Accused Products
Abstract
Disclosed are an apparatus and method for providing additional degrees of freedom for diffraction gratings of an output waveguide in a near-eye display device. The near-eye display device includes an imager to generate an image based on light from a light source. The device further includes a waveguide to input a light wave representing the image received from the imager and to output the light wave representing the image toward an optical receptor of a user. The waveguide includes a plurality of diffractive optical elements (DOEs) in a common light path from an input of the waveguide to an output of the waveguide. The DOEs include a plurality of periodic diffraction patterns. Each of the periodic diffraction patterns is represented by a diffraction pattern vector. The periodic diffraction patterns are determined such that a vector summation of the diffraction pattern vectors equals zero.
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Citations
14 Claims
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1. A near-eye display device comprising:
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an imager to generate an image based on light from a light source; and a waveguide to input a light wave representing the image received from the imager and to output the light wave representing the image toward an optical receptor of a user of the near-eye display device, the waveguide including a plurality of diffractive optical elements (DOEs) in a common light path from an input of the waveguide to an output of the waveguide, the DOEs including a plurality of periodic diffraction patterns, each of the periodic diffraction patterns being represented by a corresponding diffraction pattern vector, the periodic diffraction patterns being such that a vector summation of the diffraction pattern vectors of the plurality of DOEs equals zero, wherein the plurality of DOEs include; a first DOE to receive the light wave incident upon the first DOE in a first direction and redirect the light wave; a second DOE to receive the light wave from the first DOE and expand the light wave in a second direction, the light wave being reflected by a periodic diffraction pattern of the second DOE for an even integer number of times; and a third DOE to further expand the light wave in a third direction and redirect the expanded light wave toward the optical receptor of the user in the first direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A near-eye display device comprising:
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an imager to generate an image based on light from a light source; and a waveguide to expand a light wave representing the image into a plurality of expanded light waves exiting the waveguide in a common direction toward an optical receptor of a user of the near-eye display device, the waveguide including a plurality of periodic diffraction patterns, each of the periodic diffraction patterns being represented by a diffraction pattern vector, the periodic diffraction patterns being determined such that a weighted vector summation of the diffraction pattern vectors equals zero, wherein the weighted vector summation includes a plurality of addends, and wherein weights of the individual addends in the weighted vector summation are integer numbers; wherein the waveguide includes a plurality of diffractive optical elements (DOEs) in a common light path from an input of the waveguide to an output of the waveguide, each of the periodic diffraction patterns being on or within one of the DOEs; and wherein when the light wave propagates in a middle DOE in the middle of the common light path, the light wave is reflected an even number of times by a periodic diffraction pattern of the middle DOE and wherein a first DOE in the common light path includes two periodic diffraction patterns on each of two surfaces of the first DOE. - View Dependent Claims (11, 12, 13)
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14. A method comprising:
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generating an image by an imager based on light from a light source; receiving a light wave representing the image incident upon a first diffractive optical element (DOE) of a waveguide in a first direction and redirecting the light wave to a second DOE of the waveguide by a first periodic diffraction pattern of the first DOE; expanding the light wave in a second direction by a second periodic diffraction pattern of the second DOE and redirecting the light wave to a third DOE of the waveguide; and further expanding the light wave in a third direction by a third periodic diffraction pattern of the third DOE and redirecting the light wave toward an optical receptor of a user in the first direction; wherein a weighted vector summation of diffraction pattern vectors of the first, second and third periodic diffraction patterns equals zero, wherein the weighted vector summation includes a plurality of addends, and wherein weights of the individual addends in the weighted vector summation are integer numbers; and wherein when the light wave propagates in the second DOE in the middle of the common light path, the light wave is reflected an even number of times by a periodic diffraction pattern of the second DOE and wherein the first DOE in the common light path includes two periodic diffraction patterns on each of two surfaces of the first DOE.
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Specification