Abstract: A solar concentrator comprises a curved linear Fresnel lens (16) which has a plurality of prismatic features (10, 12, 14). The prismatic features are arranged into at least two segments, in each segment the prismatic features have a common apex angle, the common apex angle differing between adjacent segments. A method of manufacturing a mold (2) for producing a Fresnel lens optical film (16) is disclosed. The method comprises rotating a mold blank, and forming a plurality of different prismatic features (10, 12, 14) on the mold blank by repeatedly advancing a cutting tool (4) onto and then withdrawing the tool away from the surface of the mold blank.

Abstract: A point focus thin film Fresnel lens (15; 25) has an inner, substantially flat region (8; 22), and an outer region (9; 23), the outer region projecting outwardly from the inner region and at a substantial angle away from the plane of the inner region. In one embodiment the lens is in the form of a truncated cone (15) with a circular inner region as its apex, hi another embodiment the lens is in the form of a dome (25) and the outer region is formed by joining together segments (23) extending radially from a circular central region (22).

Abstract: The present invention provides a nanostructure comprising a plurality of nanoridges wherein the height of each nanoridge is modulated whereby to form one or more peaks (e.g. a series of peaks) along the length of each nanoridge.

Abstract: A solar concentrator comprises a curved linear Fresnel lens (16) which has a plurality of prismatic features (10, 12, 14). The prismatic features are arranged into at least two segments, in each segment the prismatic features have a common apex angle, the common apex angle differing between adjacent segments. A method of manufacturing a mould (2) for producing a Fresnel lens optical film (16) is disclosed. The method comprises rotating a mould blank, and forming a plurality of different prismatic features (10, 12, 14) on the mould blank by repeatedly advancing a cutting tool (4) onto and then withdrawing the tool away from the surface of the mould blank.

Abstract: Disclosed are structured optical films and optical displays incorporating such films. The film has a structured surface including a plurality of substantially parallel and elongate light-directing elements. Each element has a respective peak and defining at a junction with an adjacent element a respective valley. Each of the peaks and valleys define substantially the same dihedral angle and extend substantially uninterrupted across the structured surface. A first sequence defined by successive lateral distances between adjacent peaks is a first non-periodic sequence. A second sequence defined by successive lateral distances between adjacent valleys is a second non-periodic sequence. The second sequence is configured based on the first sequence, such that the peaks are arranged in a substantially coplanar formation. Alternatively, the first sequence is configured based on the second sequence, such that the valleys are arranged in a substantially coplanar formation.

Abstract: A rear projection display method and system, for displaying an image. The system comprises projection means (18L, 18R) to project first and second stereoscopic image components; a first light-redirecting panel (20R) and a second downstream light-redirecting panel (20L) to receive light representative of the first and second image components, respectively, from the projection means and to redirect that light substantially in a downstream direction, the first and second panels arranged to spatially multiplex the first and second image components; and a parallax optic element (22) located downstream of the second panel to provide at a downstream viewing zone (24) the first and second image components for autostereoscopic viewing of the image. The projection means may be switchable between 2D and 3D viewing modes. A 3D image may be produced by simultaneously or sequentially projecting a series of 2D image sections, using diffuser elements (45). A method of displaying a 3D image is also disclosed.

Abstract: An optical device such as an overlay panel for a LCD display, comprises an element of light-transmitting material having a surface configured to form a stepped Fresnel prismatic structure. The light-transmitting material itself or ribbed light refracting element, said element incorporates an array of graded refractive index features adapted to impart light dispersing of diffusing characteristics to the light-transmitting material. In an alternative arrangement, the element of light-transmitting material has a layer configured to form a stepped Fresnel-type surface and an additional layer incorporating such an array of graded refractive index features.