Abstract: A see-through head or helmet mounted display device (10) comprises a see-through member (18) having a see-through area (22). The see-through member (18) includes a plurality of display segments (20; 20a, 20b) for emitting visible light. The plurality of display segments (20; 20a, 20b) is provided within the see-through area (22) in a mutually spaced manner such that the see-through area (22) includes a see-through zone (24) between each pair of adjacent display segments (20; 20a, 20b). The see-through zone (24) allows visible light to pass through the see-through member (18). The see-through member (18) further includes a plurality of holographic optical elements (26; 26a, 26b) provided within the see-through area (22). Each holographic optical element (26; 26a, 26b) is associated with a respective display segment (20; 20a, 20b).

Abstract: A see-through head or helmet mounted display device (10) comprises a see-through member (18) having a see-through area (22). The see-through member (18) includes a plurality of display segments (20; 20a, 20b) for emitting visible light. The plurality of display segments (20; 20a, 20b) is provided within the see-through area (22) in a mutually spaced manner such that the see-through area (22) includes a see-through zone (24) between each pair of adjacent display segments (20; 20a, 20b). The see-through zone (24) allows visible light to pass through the see-through member (18). The see-through member (18) further includes a plurality of holographic optical elements (26; 26a, 26b) provided within the see-through area (22). Each holographic optical element (26; 26a, 26b) is associated with a respective display segment (20; 20a, 20b).

Abstract: An optical device generated by interferometric lithography, in the form of a surface relief pattern that diffracts light, to be used mainly in optical security, produced by optical systems compliant with the Schimpflug and hinge Rules containing: two identical lenses L1 and L2, two physical object location B1 e B2 and one image plane A1?A2. No physical mask is needed throughout the origination process, thus eliminating any kind of border effects. The device actually implements an in-plane focused hologram, with a complex surface pattern of valleys and ridges with a non-trivial generating function, which is, by itself, both an additional security feature of the device and its fingerprint. The time to generate the optical device is proportional to the number of colours specified for the reference geometry and not depend on the overall area of the optical device.

Abstract: An optical device generated by interferometric lithography, in the form of a surface relief pattern that diffracts light, to be used mainly in optical security, produced by optical systems compliant with the Schimpflug and hinge Rules containing: two identical lenses L1 and L2, two physical object location B1 e B2 and one image plane A1?A2. No physical mask is needed throughout the origination process, thus eliminating any kind of border effects. The device actually implements an in-plane focused hologram, with a complex surface pattern of valleys and ridges with a non-trivial generating function, which is, by itself, both an additional security feature of the device and its fingerprint. The time to generate the optical device is proportional to the number of colours specified for the reference geometry and not depend on the overall area of the optical device.