Abstract: A ground level illumination system such as a road stud comprises a light source (12) positioned below ground level (8). An optics block (9) and a top block (2) transmit light from the source (12) to the exterior, the light rising at a shallow angle as a collimated beam in the top block (2) to emerge at a window (4) above the ground level (8). The window (4) is shaped to refract the light into a beam (16) that descends at a shallow angle relative to the ground level (8). The emerging beam (16) may be used to illuminate road markings (26) formed from luminous paint that can be re-charged by the illumination system. A feedback mechanism (82) can measure reflected light levels to maintain the optimal “charge” in the paint. A further element (84) of the system may also compare the intensity of reflected light at different wavelengths to detect the presence of fog.

Abstract: A ground level illumination system such as a road stud comprises a light source (12) positioned below ground level (8). An optics block (9) and a top block (2) transmit light from the source (12) to the exterior, the light rising at a shallow angle as a collimated beam in the top block (2) to emerge at a window (4) above the ground level (8). The window (4) is shaped to refract the light into a beam (16) that descends at a shallow angle relative to the ground level (8). The emerging beam (16) may be used to illuminate road markings (26) formed from luminous paint that can be re-charged by the illumination system. A feedback mechanism (82) can measure reflected light levels to maintain the optimal “charge” in the paint. A further element (84) of the system may also compare the intensity of reflected light at different wavelengths to detect the presence of fog.

Abstract: A passive infra red detector comprises a plurality of passive infra red sensors (4, 5) and a lens member (2) arranged to direct radiation from a target area onto the sensors. The lens member (2) forms a substantially hemispherical dome about the infra red sensors (4, 5). The dome has a central axis and a plurality of contiguous facets (2a-2g) distributed about the central axis. Each facet has a flat outer surface and an inner surface that forms a lens to direct radiation onto the sensors. The detector further comprises a first passive infra red sensor (4) aligned with the central axis of the dome and having a sensitive surface substantially normal to the central axis, and a plurality of second passive infra red sensors (5) distributed about the central axis of the dome. The second passive infra red sensors (5) are inclined such that the outward normal from the sensitive surface of each second passive infra red sensor (5) makes an acute angle with the outward direction of the central axis.

Abstract: A passive infra red detector comprises a plurality of passive infra red sensors (4, 5) and a lens member (2) arranged to direct radiation from a target area onto the sensors. The lens member (2) forms a substantially hemispherical dome about the infra red sensors (4, 5). The dome has a central axis and a plurality of contiguous facets (2a-2g) distributed about the central axis. Each facet has a flat outer surface and an inner surface that forms a lens to direct radiation onto the sensors. The detector further comprises a first passive infra red sensor (4) aligned with the central axis of the dome and having a sensitive surface substantially normal to the central axis, and a plurality of second passive infra red sensors (5) distributed about the central axis of the dome. The second passive infra red sensors (5) are inclined such that the outward normal from the sensitive surface of each second passive infra red sensor (5) makes an acute angle with the outward direction of the central axis.

Abstract: A wide angle viewing apparatus for security applications is disclosed. The apparatus comprises a wide-angle lens and a diffusing screen. The wide-angle lens incorporates an image inverter and a means for eliminating stray light.

Abstract: A garment such as a sports shirt has concealed ventilation channels, which provide a continuous air channel between permanent openings. In one embodiment, the channels are flexible and non-intrusive and the openings are maintained by springy eyelets. The eyelets and channels are attached to the main fabric of the garment, providing a robust and a streamlined construction. Another embodiment incorporates active ventilation structures within the channels, the structures having a natural vibration frequency matched to a motion frequency spectrum of the wearer. In a further embodiment, the ventilation channels are made of shape memory polymer and change shape in response to changes in temperature.

Abstract: A wide angle viewing apparatus for security applications is disclosed. The apparatus comprises a wide-angle lens and a diffusing screen. The wide-angle lens incorporates an image inverter and a means for eliminating stray light.

Abstract: A method of knitting is performed by a knitting machine having two needle beds and double-ended needles transferable between the two beds, for knitting a ventilated garment panel in which a ventilation channel is formed as part of the base knitted structure. The final article is knitted in one piece. The part of the garment incorporating the ventilation channel is knitted as a three-layer fabric so that the ventilation channel formed by two side walls and one front wall is open to the inside of the garment panel through a wale-wise opening and to the outside of the garment panel at the ends of the ventilation panel.

Abstract: An optical retro-reflective apparatus for application to reconfigurable displays for highway signs and other applications is disclosed. In a first preferred embodiment, the apparatus includes a retro-reflector such as a corner cube prism, three orthogonally arranged planer reflectors, or a plurality of either arranged as an array, or an array of micro-spheres or micro-prisms arranged as a corner-cube. In one embodiment, a holographic diffraction element is placed between a source of radiation such as visible light and one or more of the retro-reflectors. The diffraction element is made up of one or more stacked holographic devices in which pre-determined holographs are stored, operative to diffract a particular wavelength band of radiation (e.g. red, blue and green visible light). The hologram devices can be stacked and selectively deactivated so that the desired wavelength band (or color) to be diffracted is selected.