Image display apparatus
First Claim
1. An image display apparatus comprising:
- an image-forming element configured to form an original image;
an optical system configured to guide light from the image-forming element to an exit pupil; and
a diffractive optical element disposed between the image-forming element and the optical system or between the optical system and the exit pupil,wherein the diffractive optical element includes plural diffraction grating portions formed of mutually different materials, the plural diffraction grating portions being disposed with a gap therebetween,wherein each of the diffraction grating portions includes plural grating rings each having a grating surface and a grating side surface,wherein, in each of the grating rings, the grating side surface is inclined oppositely to the grating surface with respect to a normal to an enveloping surface passing through apexes of the plural grating rings, andwherein the diffractive optical element satisfies the following conditions for a k-th grating ring of the plural grating rings in a j-th diffraction grating portion of the plural diffraction grating portions, at least when k=kE;
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Accused Products
Abstract
The image display apparatus includes an image-forming element, an optical system guiding light from the image-forming element to an exit pupil, and a diffractive optical element disposed between the image-forming element and the optical system or between the optical system and the exit pupil. The diffractive optical element includes plural diffraction grating portions formed of mutually different materials. Each of the diffraction grating portions includes plural grating rings each having a grating surface and a grating side surface. In each of the grating rings, the grating side surface is inclined oppositely to the grating surface with respect to a normal to an enveloping surface passing through apexes of the plural grating rings. The diffractive optical element satisfies the following conditions at least when k=kE: θd(j, k)=sin−1 [{ni·sinθi (j, k)−m(j, k)·λ/P(j, k)}/nd]≦θi(j, k), M(k)=Σ{m(j, k)}=const, and θd(j, k)≦θ≦θi (j, k).
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Citations
4 Claims
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1. An image display apparatus comprising:
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an image-forming element configured to form an original image; an optical system configured to guide light from the image-forming element to an exit pupil; and a diffractive optical element disposed between the image-forming element and the optical system or between the optical system and the exit pupil, wherein the diffractive optical element includes plural diffraction grating portions formed of mutually different materials, the plural diffraction grating portions being disposed with a gap therebetween, wherein each of the diffraction grating portions includes plural grating rings each having a grating surface and a grating side surface, wherein, in each of the grating rings, the grating side surface is inclined oppositely to the grating surface with respect to a normal to an enveloping surface passing through apexes of the plural grating rings, and wherein the diffractive optical element satisfies the following conditions for a k-th grating ring of the plural grating rings in a j-th diffraction grating portion of the plural diffraction grating portions, at least when k=kE; - View Dependent Claims (2)
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3. An image display apparatus, comprising:
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an image-forming element configured to form an original image; an optical system configured to guide light from the image-forming element to an exit pupil; and a diffractive optical element disposed between the image-forming element and the optical system or between the optical system and the exit pupil, wherein the diffractive optical element includes plural diffraction grating portions formed of mutually different materials, the plural diffraction grating portions being disposed with a gap therebetween, wherein each of the diffraction grating portions includes plural grating rings each having a grating surface and a grating side surface, wherein in each of the grating rings, the grating side surface is inclined to a same side as the grating surface with respect to a normal to an enveloping surface passing through apexes of the plural grating rings, and wherein the diffractive optical element satisfies the following conditions for a k-th grating ring of the plural grating rings in a j-th diffraction grating portion of the plural diffraction grating portions, at least when k=kE; - View Dependent Claims (4)
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Specification