An optical warning system comprises a light head that includes a light source emitting light rays from a light-emitting area. The light rays propagate through an optical diffuser to provide a visual warning signal to an observer remotely located from the optical warning system. A Fresnel optic array positioned between the optical diffuser and the light-emitting area is spaced apart from and spatially aligned with the light-emitting area to receive the light rays emitted from the light-emitting area and form a collimated light beam. The Fresnel optic array is fabricated so that it exhibits increased optical transmission efficiency by reducing light lost to scattering in forming the collimated light beam.

A method of manufacture of an optical element for focusing electromagnetic radiation, comprising the steps of:•(a) providing a first light-transmissive glass substrate (20) having a front surface on which the electromagnetic radiation is incident in use and a back surface opposite to the front surface;•(b) applying a liquid silicone resin (30) to the back and/or the front surface of the glass substrate;•(c) contacting the liquid silicone resin with a mould such that the liquid silicone resin adopts the form of the mould and forms microstructures extending over the surface(s) of the glass substrate to which the liquid silicone resin has been applied;•(d) curing the liquid silicone resin to form a microstructured light-transmissive silicone coating wherein the glass surface has been

C roughened before application of the silicone.

An optical lens device for a head-mounted display includes a transparent support substrate and a Fresnel lens disposed thereon. The Fresnel lens includes a central lens element and a plurality of prismatic elements arranged relative to the central lens element in a proximal-to-distal manner. Each of the prismatic elements has a base facing toward the support substrate, and a draft facet and a sloped facet extending from the base away from the support substrate to intersect with each other to form an apex. Each of the prismatic elements has a height measured from the base to the apex and not greater than 75 μm. The base has a width not greater than 250 μm. A method and a mold for producing the optical lens device are also disclosed.

A method and an apparatus for producing a relief-pattern forming, the method and apparatus being suitable for producing a film-like material, such as an embossed film, having a fine relief-structure pattern formed on a surface thereof so as to have a distinctive optical effect with higher quality, good productivity, and fewer defects. A transfer pattern printed layer having an inverted structure of a relief-structure pattern is formed on a second substrate by printing a transfer pattern onto the surface of a first substrate on which the relief-structure pattern is formed at a predetermined position by registration with the relief-structure pattern followed by drying, laminating with the second substrate, curing and peeling.

A lens includes a cover part and an interposing member formed of a light-reflecting material. The cover part includes a lens part having a lateral side, a connection part constituting a lateral side wall extending from the lateral side, and a flange part having a lower surface disposed below the lateral side wall. The interposing member has an upper surface and an inner lateral surface. The upper surface is disposed on the lower surface of the flange part. The lens part and the interposing member define a recess having an opening facing downward. The lens part defines a bottom surface of the recess. The inner lateral surface defines a lateral surface of the recess, which defines the opening of the recess. The flange part extends outward from the opening. The lens part has a convex lens and a light-emitting surface with projections outward from the convex lens.

An optical lens device for a head-mounted display includes a transparent support substrate and a Fresnel lens disposed thereon. The Fresnel lens includes a central lens element and a plurality of prismatic elements arranged relative to the central lens element in a proximal-to-distal manner. Each of the prismatic elements has a base facing toward the support substrate, and a draft facet and a sloped facet extending from the base away from the support substrate to intersect with each other to form an apex. Each of the prismatic elements has a height measured from the base to the apex and not greater than 75 μm. The base has a width not greater than 250 μm. A method and a mold for producing the optical lens device are also disclosed.

A Fresnel lens for a concentrator photovoltaic apparatus includes: a glass substrate portion having a circular first corner portion; and a synthetic resin portion overlaid on one surface of the glass substrate portion and having a circular second corner portion having a radius equal to that of the first corner portion and coaxially overlapping the first corner portion.

There are provided a video projecting structure, which is capable of having not only transparency but also high visibility of a video, a process for producing the same, and a video display system including the video projection structure. A video projecting structure includes a first transparent layer having irregularities disposed on a surface thereof, a reflective layer disposed on the surface of the first transparent layer, and a second transparent layer disposed on the reflective layer; wherein when a surface of the first transparent layer opposite to the reflective layer is defined as a reference surface, the irregularities include a plurality of slant surfaces slant to the reference surface and reflecting light from a video; wherein when a first direction, a second direction and a third direction are defined such that the first direction is perpendicular to a normal direction of the reference surface, the slant surfaces extend in the first direction, the second direction is orthogonal to the first direction, the slant surfaces are arrayed in the second direction, and the third direction is a direction in which the slant surfaces have an average slant angle θ to the reference surface in section in the second direction; the irregularities include a portion which is configured such that when an average spacing Sm.sub.1 of the irregularities in the first direction, an average spacing Sm.sub.2 of the irregularities in the second direction and an average spacing Sm.sub.3 of the irregularities in the third direction are such that Sm.sub.2>Sm.sub.1 and Sm.sub.3>Sm.sub.1 are met, and Sm.sub.2 is maximum; and wherein the irregularities include a portion which is configured such that when a frequency distribution of inclinations of the irregularities in the second direction to the reference surface is measured in 0.25° divisions in every distance of 1 mm in order that the frequencies are represented as distances, the absolute value of a median value in the frequency distribution is a value other than 0°.

A mold insert for a tooling device for producing an optical component by injection molding, wherein the mold insert is formed at least in part of copper beryllium.

An optical lens, mold for optical lens and manufacturing method thereof are provided, wherein the optical lens includes a spiral surface spiraling around an axial direction and an intermediate structure around which the spiral surface spirals, the intermediate structure extends axially relative to a side of the spiral surface, and two ends of the spiral surface defines a stepped difference. The structure of the mold and the optical lens are correspondingly complementary. The manufacturing method of the mold includes following steps of: providing a base, the base including a processing surface; processing the processing surface to form the spiral surface, the intermediate structure and the stepped difference of the mold.