MX2007008591A - Special or security paper comprising internal touch recognition elements - Google Patents

Abstract

The invention relates to special or security paper comprising internal touch recognition elements, which is suitable for use as legal tender or for any other type of document requiring means for facilitating touch recognition or preventing counterfeiting. The invention comprises a sheet of paper (1) containing inserted expanding agents (2) which may be centred in relation to the thickness of the sheet of paper or positioned close to the upper face and/or lower face of the sheet (1), such as to form a figure or legend. According to the invention, pressure and heat are applied to the aforementioned expanding agents, either as the paper is being produced or during subsequent processes, thereby causing the sheet (1) to expand and forming a curved, continuous relief (3) on the surface of the document.

Description

SOLAR LIQUID LENS DESCRIPTION OBJECT OF THE INVENTION The present invention relates to a solar energy concentrating lens, characterized by its construction without spherical or geometric aberration, as well as being basically biconvex and being formed by various containers in which a refractive fluid is housed. This sensibly flat lens has dimensions and shapes suitable for the focal length and type of predefined focus, in order to minimize optical losses.

BACKGROUND OF THE INVENTION The use of conventional lenses for the capture of solar energy, presents serious drawbacks, mainly due to its high cost and high weight which hinders the construction of large lenses to capture large amount of solar light energy. On the other hand to obtain a high performance of solar energy, it is necessary to use the so-called "Black Body", for which it requires a very high optical quality, impossible to obtain with ordinary lenses. The "Black Body" is essentially a perfectly hermetically sealed and thermally insulated enclosure, to avoid the escape of internal heat, in which a small hole (window) has been made, through which a beam of light penetrates. the maximum intensity possible.

The Fresnel lens, invented at the beginning of the 19th century, is characterized by being a thin lens with the possibility of a large size, which has reached our days without any improvement in its optical characteristics that allow an acceptable degree of concentration. for use as solar collectors of large dimensions and small focal length. Each one of the zones, rings or crowns that integrate it comes from the section of a planoconvex lens and has the angle of curvature of the corresponding part of the aperture of the lens from which it proceeds, thus giving rise to the Fresnel lens. The Fresnel lens has a low optical quality, great spherical aberration, numerous light losses due to its morphology, great focal inaccuracy and high cost; consequently, it is only used in functions in which optical precision is not necessary, which considerably limits its field of application. The accumulated experience in the development of the liquid lens modulated without spherical aberration, has made possible the application of similar techniques to solve the serious problems that the Fresnel lens presents.

DESCRIPTION OF THE INVENTION The solar liquid lens is obtained as a result of introducing a series of modifications and rectifications in the Fresnel lens to solve the problems that it presents in relation to the concentration of solar energy, these are: 1. - Regarding cost and weight. The high cost of the Fresnel lens is mainly due to its laborious manufacturing process, generally of solid glass, with high weight. This is solved by modulating the rings or facets of the Fresnel lens, in small containers containing a transparent, liquid, semi-liquid or solidifiable refracting fluid, suitably and differently for each container, which configure each zone, ring or crown and the set of them form the lens in its entirety, with which these disadvantages are solved. The construction of these containers, will be carried out by a process similar to that used in the industry for the manufacture of bottles and other containers, for which processes of molding, injection, extrusion, etc. are used. and the use of different types of molds to give them shape, depending on whether they are circular or cylindrical lenses. 2. - Regarding its light loss. The luminous losses in the Fresnel lens are produced in the upper surface of the same, which are evaluated in 30% of their total capacity of approximate uptake. These losses are due both to the angle of the upper facets and to the fact of eliminating the superior curvature, replacing it with a flat section and rounding the corners of the flat areas. In order to minimize these losses, the slope of the curvature of the upper facet of each of the longitudinal vessels, rings or crowns, is gradually reduced, the same for those that make up each ring, so that the height of the respective steps remains significantly reduced, achieving, with this solution, that the losses for this concept are less than 3% of the total capacity of light collection. 3. - Regarding its optical quality and aberrations. The low optical quality and aberrations that the Fresnel lens presents, generate a high dispersion of the captured light, around the theoretical focus of the lens. In order to overcome these drawbacks, the following actions have been carried out: a) First, its flat lower part is replaced by curvature sections, which differ in radius and slope for each zone, ring or crown, to the object to achieve the proper deviation of each optical beam accurately. b) Secondly, the refractive index of the fluid in each of the zones, rings or crowns that require it is modified, in order that the slope of the lower curvature is as small as possible and consequently reduce the thickness of the containers. The radius of curvature of each upper and lower facet, as well as the refractive index, must be calculated with precision for each zone, ring or crown, in order that the concentration is optimal in the focus. The aforementioned modifications significantly affect the classic structure of the Fresnel lens, optimizing its optical qualities. The solar thus obtained has the following advantages: a) Very low production cost and minimum weight. b) Loss of light energy by reflection, less than 3%. c) Perfect light convergence in the focus, being able to direct the light rays with absolute precision. d) Elimination of spherical aberration with optimum concentration factor. e) It is sensibly flat, because the zones, rings or crowns that compose it approach the same horizontal plane.

The containers that make up each ring or crown of the circular liquid solar lens, are identical to each other, with curved upper and lower facets, which generates a circular focus. This type of lens has its origin when projecting the curvature sections on the flat base of a conventional convex flat spherical lens.

The containers that make up each linear zone of the solar liquid lens of rectangular shape, are identical to each other, with curved upper and lower facets, which generates a linear focus. This type of lens has its origin when projecting the curvature sections on the flat base of a conventional convex cylindrical plane lens. The liquid solar lens adopts a configuration with double curvature for each zone, ring or crown, a curvature in the upper part whose radius can be the same for different zones, rings or crowns, and another lower curvature whose radius will be generally different for each zone , ring or crown, which will depend on the distance to the optical axis and the refractive index of the fluid of each zone, ring or crown, and a double staggered with respect to the horizontal plane, very small on the upper part to minimize light losses, and more prominent at the bottom to achieve a perfect convergence of sunlight.

DESCRIPTION OF THE DRAWINGS The present specification is complemented with a set of plans, illustrative of the preferred and never limiting example of the invention. Figure 1 is an elevation view of the solar liquid lens of the invention, in its rectangular linear execution, observing in it its slight convex external curvature, whose arrow (a) is determined by the height with respect to its theoretical plane position. Figure 2 is a section of the side end elevation of this rectangular linear lens.

PREFERRED EMBODIMENT OF THE INVENTION In view of the aforementioned, the present invention relates to a new solar liquid lens, which is formed by various transparent containers, in modules (1) of suitable geometry, constructed with procedures widely used in industry, such as: injection, blowing, extrusion, molding, rotary casting, or other systems, using materials resistant to sunlight, such as glass, polycarbonate, methacrylate, etc., by using the appropriate die-cutting in each case, essentially characterized by the modularity of the containers that make up the different zones, crowns or rings of the lens, which can be self-supporting or have an additional structure that supports them, promoting the construction of large lenses. Characterizes these modules as different containers, identical in each of the zones, rings or crowns and that differ from the containers that make up the zones, rings or crowns remaining, both in the radii of curvature, as in the slope of the curvature of their upper and lower facets. It also characterizes that the zones, rings or crowns are generally biconvex (2), being able to be planoconvex (3), with one of the convex facets (4) and another flat facet (5) or concaveconvexes (6), with a concave facet (7) and another convex facet (8) in the extreme containers of the lens, in smooth transition, having to be indeformable before the efforts to which they may be subjected and these zones, rings or crowns being arranged in a same plane , practically horizontal. It characterizes the solar liquid lens that the vertical face of the vessels, which joins the upper and lower facets, is flat and inclined toward the optical axis, following the path of sunlight to avoid light losses through interference, as well as that in order to enable solar tracking, in its horizontal and vertical rotation, the supporting structure, where appropriate, will be located in the optically neutral areas, coinciding with the vertical faces, so that they do not generate additional energy losses. It characterizes especially that the ridges or furrows that form the facets of the Fresnel lens, have been minimized, by decreasing the slope of the curve of each of the facets of this Fresnel lens, which receives a series of structural modifications, which give it a very high optical quality, by replacing its flat bottom face, by curved surfaces in each zone, ring or crown, which allow the perfect convergence of the captured solar light. Characterizes the elimination of the spherical aberration, by having transparent fluids in its interior whose index of refraction grows in each zone, ring or corona, progressively from the optical axis towards the edges of the lens, propitiating a perfect concentration of sunlight in focus. It also characterizes the reduced volume of the refractive fluid contained in each one of the containers, which allows its construction with little thickness, reducing costs and weight. The essentiality of this invention does not alter variations in materials, shape, size and arrangement of the component elements, described in a non-limiting manner, this being sufficient to proceed to its reproduction by an expert.

Claims (1)

1. CLAIMS 1 a.- Solar liquid lens, among the Fresnel lenses formed by various transparent containers constructed by injection, blow molding, extrusion, molding, rotary casting, or others, in glass, polycarbonate, methacrylate, etc., in construction with minimum thickness and weight, essentially characterized by its modulability so that these modules (1) are constituted as different containers and are identical in each of the zones, rings or crowns and, however, differ from the modules (1) that make up the areas, rings or crowns remaining, both in the radii of curvature, and in the slope of the curvature of its upper and lower facets, in biconvex configurations (2) in the central modules (1) of the lens, becoming planoconvexes (3) with one of the facets convex (4) and another facet flat (5), and finally, concaveconvexes (6) in the modules (1) end of it, with a concave facet (7) and another convex facet (8), in transition sua and all of them are non-deformable before the efforts and these zones, rings or crowns are arranged in the same plane, practically horizontal, although with a slight external convex curvature, of arrow (a) and all their ridges or ridges are minimized, as well as the vertical face, which connects the upper and lower facets of the modules (1) and, finally, the elimination of the spherical aberration, is disposed towards the optical axis by incorporation in the modules (1) of refractive fluids with different refractive index and very reduced volume. 2a.- Solar liquid lens, according to the preceding claim, characterized in that the modules (1) are self-supporting or have an additional structure that supports them. 3a.- Solar liquid lens, according to the preceding claims, characterized in that the vertical face of the modules (1) follows the path of sunlight, avoiding light losses due to interference, as well as having a bearing structure located in the zones optically neutral, coinciding with the vertical faces. 4a.- Solar liquid lens, according to the preceding claims, characterized in that to minimize the ridges or grooves the slope of the curve of each of the facets of the Fresnel lens is decreased. 5a.- Solar liquid lens, according to the preceding claims, characterized in that for the elimination of the spherical aberration, the transparent fluids inside the modules (1) have an increasing refractive index in each zone, ring or corona, progressively from the optical axis towards the edges of the lens. 6a.- Solar liquid lens, according to the preceding claims, characterized by replacing the concave convex configurations (6) in the end modules (1) of the lens with other planoconvexes (3). 7a.- Solar liquid lens, according to previous claims 1a to 5a, characterized by replacing the planoconvex (3) and concaveconvex (6) configurations in the end modules (1) of the lens with other biconvex (2) configurations.