Abstract: A head mounted information processing device, an authentication system, and an authentication method capable of achieving an improvement in security are provided. Thus, a head mounted information processing device 1 includes a display 45 configured to display an image, a microphone 50 configured to collect a voice of a user and output an audio data signal, a biometric authentication sensor 30 configured to acquire tomographic data of a head of the user, and a controller (20) configured to control the head mounted information processing device 1. The controller (20) authenticates the user based on the tomographic data acquired by the biometric authentication sensor 30 during an authentication period in which the user is uttering a passcode.

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.