EP3356868A1

EP3356868A1 - Retroreflective sign, retroreflective strip material and method for producing same

Info

Publication number: EP3356868A1
Application number: EP16784804.3A
Authority: EP
Inventors: Bernd Pfundstein
Original assignee: Erich Utsch AG
Current assignee: Erich Utsch AG
Priority date: 2015-10-01
Filing date: 2016-09-29
Publication date: 2018-08-08
Also published as: DE102015116715A1; WO2017055516A1

Abstract

The invention relates to a retroreflective sign and strip material having a triple-mirror structure, wherein the triple-mirror structure comprises a triple mirror (1) having at least three mirror surfaces (2, 4 and 6), arranged at right angles to each other, for retroreflection, wherein the triple mirror (1) is designed as a recess in a surface (8) of the sign or the strip material. The invention also relates to a method for producing a retroreflective sign.

Description

The present invention relates to a retroreflective shield, a retroreflective tape material, and a method of making a retroreflective shield.

From the prior art vehicle license plate with a board on the front side, a retroreflective sheeting is laminated, has long been known. The use of retroreflective sheeting for license plate or signage is mandatory in a variety of countries through their respective national registration requirements. Retroreflective license plates or signs have a high detectability under retroreflective condition due to their retroreflectivity.

Regulations on retroreflective materials for traffic safety and lighting requirements for reflective fabrics are deposited, for example, in DIN 67520. There, retroreflective materials are classified according to the luminance perceived by a road user from a considered traffic sign. The construction of the considered retroreflective structures is irrelevant. The reflection classes (RA classes) describe the minimum requirements for a material with regard to a specific retroreflective value. The structural design of a selected reflection material has a great importance. Currently, the structure determines the durability of a sign as well as the reflection reserves of a reflective fabric. The performance of modern microprismatic films is superior to those of older glass-blowing technology, which has long been known from the prior art.

The requirements for reflective fabrics for license plates and traffic signs have increased in recent years. Furthermore, it can be assumed that these requirements will continue to increase in the future. Various factors played a role, such as the diminishing visual performance of an increasing number of older drivers, the need for traffic signs to be perceived in the increased urban ambient brightness and the increasing overhead signage, which can hardly be achieved by the bundled light beam of modern vehicle headlights. These are just a few examples intended to demonstrate that the demand for reflective films to be used in the future has a high demand for a high performance retroreflective coating and a need for large scale applications.

Due to their photometric properties, reflective films are classified into the reflection classes RA 1, RA 2 and RA 3. These are characteristic for the requirements of the specific reflection value (RA), which is decisive for the choice of the reflective foil. According to the different constructions, the reflective foil construction is differentiated according to the structure A, the structure B and the structure C. The structure A comprises a base reflective foil and glass beads. In this case, a transparent intermediate layer is provided between the reflective foil and the glass spheres so that the spheres act as a thick lens and a light beam incident on the sphere is refracted such that its focal point lies substantially behind the sphere substantially on the reflective layer. This reflects light back in a narrow angle to the light source.

Reflective films with the structure B represent a more retroreflective film based on encapsulated glass spheres. In this case, a reflection layer lies in a region directly against the glass spheres. This ensures that retroreflection can be achieved in a wider viewing angle range than type A foils. Furthermore, in this type of film, an air cushion can be arranged above the balls to the incident light.

Reflective films with the structure C have a reflective layer within the film based on a microprismatic technology. These types of foils exceed the requirements of glassblowing technology. In films of the structure C, a layer having a prismatic structure is applied to a carrier layer, which is further coated with a cover layer toward the reflective side. Reflective films of the structure C are complicated to produce due to the micro-prism technology. Several layers must be connected. In addition to the reflective side, a suitable transparent layer must be applied to protect the microprismatic structure, since it is very sensitive. In road traffic, retroreflectors are also known from the prior art, which are used, for example, on people, obstacles, traffic signs, guidance devices and vehicles to improve their visibility at night in the spotlight. Retroreflektoren throw against the direction of incidence back a light beam to the light source. So that the observer does not have to look directly into the reflected light beam, irradiated retroreflective agents work best if they have a small angular spread, but even if they are illuminated obliquely, they have good effects. These two parameters characterize retroreflective elements. In white or colored versions, triple mirror structures are known as reflectors made of transparent materials. These structures have a smooth surface in the direction of irradiation. From the back, such reflectors have a structure of many prominent cube corners. For reflection, these reflectors need not be mirrored, since inside the material, a total reflection results inside the material at the interface between the cube corners and the air. These elements are often referred to as cat's eyes.

The object of the present invention is to provide an improved variant of a retroreflective shield and an improved production method.

This object is achieved by a retroreflective shield having the features of claim 1, a retroreflective belt material having the features of claim 16, and a method of making a retroreflective shield having the features of claim 30. Advantageous further embodiments are specified in each of the subclaims. All combinations, as well as only individual combinations, between the retroreflective shield, the retroreflective strip material and the method for producing a retroreflective shield can be used together. Furthermore, it is also envisaged and possible to use one or more features. male of the shield, the band material and the method to combine arbitrarily.

To solve the problem, inter alia, described from the air side of the shield from the corner mirror structure, ie. the shield is designed for the front surface retroreflective. The described features of the cusp mirror structure can all be expressly applied to the retroreflective shield, the retroreflective ribbon, and the described method of making a retroreflective shield.

Furthermore, in the following description, a triple mirror structure in a body will be described. The body can also be designed as a shield or band material. According to the invention, a front surface retroreflective shield is proposed comprising a triple mirror structure, wherein the triple mirror structure comprises a triple mirror with at least three mutually perpendicular mirror faces for retroreflection, wherein the triple mirror is formed as a recess in a surface of the shield and forms mirror surfaces, which mirror from the air side are formed. It is preferred that the shield is made of metal at least in the region of the mirror surfaces. As the metal, aluminum or an aluminum alloy is particularly preferred.

The shield according to the invention and the strip material according to the invention therefore differ from the prior art widely known retoreflectors based on prismatic elements in that the retroreflection is not based on total internal reflection on the surfaces of the prismatic elements, but on a front surface Reflection on the mirror surfaces of the triple mirror structure, ie. seen from the air side of the retroreflective shield or tape.

It should be noted that the exterior surfaces of a prismatic element-based retroreflector based on total internal reflection, when illuminated from the air side, form retroreflective corner mirrors, even when the prismatic surfaces are mirrored. This is due to the fact that the geometry of the body surface, in which the prismatic Seen surfaces are formed, is different, depending on whether they are viewed from the inside of the body or from the air side of the body. A geometry in which retroreflection occurs is always possible only from one of the two half-spaces.

As a triple mirror in the context of the present invention, an arrangement of three mirror surfaces is meant perpendicular to each other in the three spatial planes, so that these three mirror surfaces are suitable as a reflector to retroreflect incident light. Retroreflective in this context means to throw back an incident light beam to the source irrespective of the angle of incidence.

From the road, it is known from cat's eyes that their external structure, namely protruding cube corners, in combination with the transition at the surfaces of the cube corners to the air leads to total internal reflection. The invention uses only the geometry of triple mirror surfaces. However, the mirror surfaces are not first formed by total internal reflection in the interior of a material, but according to the invention as a recess with reflective surfaces, which are arranged as a triple mirror to each other at right angles in the three spatial planes provided.

It can also be provided that depressions are introduced into a surface of a shield, which are formed only in regions as mirror surfaces. For the formation of triple mirrors always at least three surfaces are necessary. However, it is also possible that a multiple of three is provided on mirror surfaces. For example, a depression in a shield can also be equipped with six or nine mirror surfaces. The prerequisite for the formation of a triple mirror for retroreflection is merely that in each case three mirror surfaces in the three spatial directions are arranged at right angles to each other so as to retroreflect at least part of the incident light. In each case three mirror surfaces which are arranged in three mutually perpendicular spatial directions, then form a triple mirror.

In a further embodiment it is provided that the mirror surfaces form a tip. In a further embodiment it is provided that the tip forms the lowest point of the depression. In a further embodiment it is provided that the mirror surfaces are triangular. Furthermore, it can also be provided that the mirror surfaces are quadrangular, preferably square. A triple mirror structure with square-shaped mirror surfaces is referred to below as "full cubes." In a further embodiment, it is provided that the triple mirror has a triangular base area.

Although the three mirror surfaces of a triple mirror for its retroreflective function must be arranged at right angles to each other only in three spatial planes, it is preferred that the triple mirrors are formed as a recess in the surface of the shield, that this recess is formed as an impression of a cube corner. It follows that the impression of the corner of a cube is formed as a tip of the depression, which then represents the lowest point of the depression. Furthermore, it follows that the three mirror surfaces are configured substantially triangular. The base of the recess as a triple mirror results in a substantially triangular shape. The mirror surface in this context is a reflective surface, i. E. The mirror surfaces provide a sufficiently smooth surface to reflect light or other radiation. A triple mirror structure with square-shaped mirrors as a "full-cubes" structure is also possible, since the degree of retroreflection of a triple mirror can be influenced both by the size of the mirror surfaces and by the surface properties of the mirror surfaces.

The requirements for the degree of reflection vary depending on the application. The degree of reflection can be adjusted for example by the size of the mirror surfaces. The smaller the mirror surface the less reflection, the bigger the more. It is conceivable, on the one hand, that a corner of a cube is introduced into the shield only in a shallow depth as an impression. Furthermore, it is also conceivable that the area, which is configured as a reflecting mirror surface for a triple mirror, is adapted in size in a depression. On the other hand, the degree of retroreflection can also be adapted by the surfaces of the mirror surfaces by more or less reflective mirror surfaces. In this case, a triple mirror with strongly reflecting mirror surfaces reflects more light than a triple mirror, in which the mirror surfaces, or at least one mirror surface, have a reduced degree of reflection.

Furthermore, triangular shapes and squares can be chosen for the mirror surfaces of a triplet mirror. In the choice of three identical mirror surfaces each in the form of a right triangle, there is a triple mirror, which has a directional symmetric retroreflective effect. This also applies to triple mirrors, which are formed of squares. If mirror surfaces of different formats and shapes are selected for the triple mirror, then a different degree of retroreflection results, depending on the viewing angle or angle of illumination. In a further embodiment, the triple mirror comprises a mirror surface which has at least one side with a length in the range of 70 to 400 μm.

In a further embodiment, the triple mirror structure has a microstructure at least in regions.

In a preferred embodiment, the triple mirrors are formed from triangular, mutually adjacent mirror surfaces. Thereby, the triple mirror of this embodiment is equipped as an imprint of an equilateral pyramid with equilateral triangular base in the surface of the shield. Such a triple mirror then has 6 pages. The lengths of these sides are preferably designed in the range from 70 to 400 μm.

The depth of the triple mirror structure can also be in the micrometer range. The depth of the triple mirror structure is thus the distance from the surface of the shield to the deepest point of the depression, in which the mirror surfaces of the Tripeispiegeis are designed. A depth of from 100 pm to 200 pm, particularly preferably 150 pm, is preferred. In a further preferred embodiment, the mirror surfaces are formed as smooth surfaces in a recess on the surface of the shield in the material of the shield inside. In a further embodiment, it is provided that the shield has a coating at least in the region of the mirror surfaces. The coating can be made substantially reflective.

The coating can also be transparent. In particular, it may be colored to achieve a color effect of the shield, for. White or yellow.

Preferably, the coating is based on a polymeric material, for. B. a suitable transparent acrylic paint system. The coating can fill in the triple mirrors. It is preferred that the coating at least partially has a thickness in the range from 50 pm to 500 pm, particularly preferably from 100 pm to 200 pm and in particular 150 pm. In a further embodiment, the coating can be designed for light scattering. It is preferred that the material of the coating comprises light scattering means. For example, additives in the form of microbodies can be provided. In a further embodiment it can be provided that the coating protects the mirror surfaces.

External influences can lead to changes in the mirror surfaces. For example, temperature and humidity can lead to corrosion of metal. Furthermore, contamination of the shield surface can also lead to contamination of the triple mirrors, which inhibits retroreflection. As a coating, therefore, a transparent protective layer can be provided which prevents the adhesion of dirt to the mirror surfaces or the change due to external influences of the mirror surfaces. Furthermore, it can be provided, for example, that this coating has a kind of lotus effect and thus already counteracts contamination in a preventive manner. The accumulation of condensation or the adhesion of ice and snow can also hinder the triple-mirror function of the shield. For example, a coating can be designed such that it prevents the adhesion of condensation water and / or ice and snow.

Furthermore, it can be provided that a coating simplifies the cleaning of the shield. Thus, for example, a transparent coating completely fill the structure with the triple-mirror depressions, so that no dirt of water or ice can accumulate in the depressions, which impairs the triple mirror function.

A further advantage of such a transparent coating filling the recesses is that a larger angle range is reflected by incident light, since the front surface of the transparent coating facing the light incidence causes refraction of the incident light towards the axis of symmetry.

Furthermore, a coating can be applied both in areas and on the whole shield. In an area-wise application can be provided that the coating is applied only on the mirror surfaces or only on certain areas.

Furthermore, it can be provided that a coating is transparent. A transparent coating may be colored to produce a colored reflection effect.

For example, a transparent coating can also be used as a cover-like closure against external influences over the depression in which the triple mirrors are formed.

In a further embodiment, it is provided that the coating has a metallization. For example, when forming a Tripeispiegeistruktur in the surface of a sign by means of embossing, but possibly also in other cases, it may happen that the Mirror surfaces do not have the desired reflectance. Thus, it is possible to apply an at least partially coating at least on the mirror surfaces, so that they thereby have a higher reflectance, for example by a smoother surface of the coating.

In a further embodiment, the shield metal and / or plastic and / or wood. The mirror surfaces of the triple mirror can be formed at least partially in this material. Essentially, this list is intended to emphasize that it is generally conceivable to incorporate the above-described triple mirror structure into every technically sensible material. It is possible that in the first material recesses are introduced with mirror surfaces. The mirror surfaces are arranged at right angles to each other in the three spatial directions and three mirror surfaces each represent a triple mirror. The reflectivity of such a surface can be generated in a further step by a corresponding coating.

For example, it may also be provided that only one structural form of surfaces, which are arranged perpendicular to one another in the three spatial planes, are formed in a material which initially has no front-surface reflectivity but only the geometric structure of a triple mirror. The front-surface reflectivity of these surfaces can then be achieved in a further step by applying a reflective coating at least in the region of the mirror surfaces. Due to the reflective coating, the reflector function is then only achieved. This may be necessary, for example, when a material is too rough to form reflective surfaces therein. In a further embodiment it can be provided that the material of the coating comprises aluminum, chromium or nickel or consists of these materials.

Furthermore, provision can be made for the triple mirror structure to comprise at least some of the triple mirrors. Furthermore, it can be provided that the triple mirrors are substantially adjacent to one another.

The individual triple mirrors can each have base surfaces, from which recesses are formed in the surface of the material. It can be provided that the depressions in which the triple mirrors are formed are spaced apart from one another, that is to say they are spaced apart from each other. that only a certain number per surface of the shield are present and provided therebetween an unstructured shield surface. Furthermore, it can also be provided that the triple mirrors have a triangular base surface and are formed from individual triangular mirror surfaces, wherein the sides of the triple mirror base surface adjoin one another either directly or indirectly at a distance. Due to the density of the arrangement of the triple mirrors on the surface of the shield, the degree of retroreflection of the shield can be influenced or adjusted. It is conceivable that many corner mirrors per area a high degree of retroreflection is achieved and by the arrangement of fewer triple mirrors per surface, a lower reflectance can be set.

The cusp mirror structure may be arranged on the entire shield or only partially on the shield.

In a further embodiment, a sign has a legend, for example with numbers and / or characters, in particular letters. Furthermore, it can be provided that the legend comprises a structure or pattern and / or characters which are not numbers and / or characters.

It is particularly preferred that the legend is designed relief-like and / or plastic. Furthermore, a legend can be colored.

For example, a legend can be imprinted on the sign. The raised areas can then be colored by means of a thermal transfer process. By this is meant that the raised areas, for example of numbers and / or characters by color transfer of a carrier film are dyed by heat. According to a further aspect of the invention, the use of a retroreflective shield according to the above description as a license plate and / or traffic and / or sign is additionally or separately proposed.

The above-described triple mirror structure can also be applied to a strip material from which a shield is made. Therefore, in addition to being separate from a sign discussed above according to another aspect of the invention, a retroreflective tape material is proposed.

The retroreflective strip material according to the invention has a triple mirror structure, wherein the triple mirror structure comprises a triple mirror with at least three mirror surfaces arranged at right angles to each other for retroreflection, the triple mirror being formed as a recess in a surface of the strip material. The mirror surfaces are formed from the air side of the strip material of a mirror. It is preferred that the strip material consists of metal at least in the region of the mirror surfaces. As the metal, aluminum or an aluminum alloy is particularly preferred. The triple mirror structure of the retroreflective strip material is designed like the triple mirror structure of the shield explained above. In this regard, reference is made to further explanations and explanations of the above triple mirror structure. All the features of the above-described triple mirrors and the above-explained triple mirror structure are also applicable to the strip material according to the invention.

It is preferred that the band material can be wound up, that is to say that the band material can be wound on a roll or another body, for example. If necessary, it can be processed again for further use.

In a further embodiment, it is provided that the mirror surfaces form a tip. In order to provide the triple mirror function, it is not necessary to touch three surfaces which form a triple mirror. loading However, it is preferable that three mirror surfaces form a peak and thus form a pointed recess in the surface of the strip material into it.

In a further embodiment, it is provided that this tip forms the lowest point of the depression. It is further provided that the mirror surfaces are triangular. Furthermore, it can also be provided that the triple mirror has a triangular base. Furthermore, it can also be provided that the mirror surfaces are designed substantially square.

It is particularly preferred that the triple mirrors are formed in the strip material as an impression of a cube corner. For this purpose, the triple mirrors are designed as an impression of a cube corner in the strip surface. The top of the cube corner represents the lowest point of the triple mirror. It follows that the mirror surfaces are at least partially formed as an impression of the cube surfaces. The mirror surfaces may for example be designed triangular or square and adjacent to each other. This also means that the three mirror surfaces are arranged at right angles to each other in the three spatial planes. From the impression then results in a triangular base of the recess.

As an impression of a cube corner, the triple mirror has six sides. It is particularly preferred that the triple mirror has at least one side with a length in the range of 70 to 400 pm. Furthermore, it can be provided that the triple mirror structure has a microstructure at least in some areas.

In a further embodiment, it is provided that the strip material has a coating at least in the region of the mirror surfaces. In this case, the coating can also be made reflective from the air side of the strip material. Additionally or separately, it can be provided that the coating protects the mirror surfaces. A coil coating may further have the same characteristics as the shield coating discussed above. In a further embodiment, the strip material on metal and / or plastic and / or wood. It is preferably a strip material made of metal, particularly preferably aluminum. Furthermore, it can also be provided that the strip material consists of a combination of different materials, for example a composite material. It is also possible that the mirror surfaces are only partially formed in a material suitable for reflection and partially in another material.

The cusp mirror structure may extend completely over a surface of the ribbon material or only partially.

According to a further aspect of the invention, it may also be provided to manufacture a retroreflective shield or a shield blank from the described strip material. For example, a shield blank may be cut from the retroreflective tape material, punched or cut out of the retroreflective tape material. Furthermore, the shield blank or the shield can be embossed to form a shield edge and / or a legend.

Furthermore, it can be provided that raised areas are designed for a legend. Preferably, the legend is colored. In this case, a thermal transfer method is particularly preferred, color being applied by a carrier film to the raised regions under the influence of heat.

It has surprisingly been found that impressing triple mirror structures with essentially triangular mirror surfaces into an aluminum surface gives very good results with respect to the retroreflectivity of this embossed surface. For this purpose, surfaces made of aluminum were stamped on a servohydraulic universal testing machine from Dyna-Mess with stamping dies with the diameters 48 mm and 36 mm. The stamping structure of the stamps was a structure with outstanding cube corners with a height of 150pm and triangular mirror surfaces. With these stamps, triple mirrors with triangular mirror surfaces were impressed into the aluminum material. The contact pressure of the punch with the diameter 48 mm was in the range of 50 N / mm ² up to 200 N / mm ² . For the smaller punch with a diameter of 36 mm, the contact pressure was about 180 to 360 N / mm ² . With these punches, triple mirrors with a side length of 70 to 400 pm were pressed into the aluminum material. The depth of these triple mirror structures was approximately between 20 pm and 150 pm. The result of these experiments was an aluminum surface with excellent retroreflective properties.

Therefore, in addition to and separately from the above-discussed retroreflective shield and retroreflective tape material in accordance with another aspect of the invention, a method of making a retroreflective shield as described above is also suggested. The method according to the invention has at least the following steps:

Providing a band material. Preferably, the strip material has at least on the surface at which the triple mirror structure is introduced, a metallic layer z. As aluminum or an aluminum alloy, particularly preferably the strip material made of aluminum or an aluminum alloy.

Introducing the triple structure as described above into a surface of the strip material by embossing and / or hot stamping and / or rolling and / or printing and / or stamping.

Separating a shield plate from the strip material, such as cutting, cutting or punching. In a particularly preferred embodiment of the method, the above-described triple mirror structure is first introduced into a strip material. From the strip material sections can then be worked out, for example by cutting, cutting or punching, which can be used as shield plate or shield blank. For this purpose, it can be provided, for example, that such pieces separated from the strip material are used further directly as a shield. The shield plates can also be subjected to further processing steps, such as, for example, introducing a legend or further shaping processing. Furthermore, it is also possible for shield plates to be first separated from a band material provided, into which the triple mirror structure according to the above description is introduced. However, it is preferred that at least partially the described triple mirror structure is introduced into the band material provided in a continuous production process. In this case, it is advantageous, for example, if the strip material is processed in a process from roll to roll. In this case, it is meant that a strip material without a triple mirror structure is continuously provided with the described structure and then rewound onto a roll in a state with a triple mirror structure. The strip material wound on a roll provided with the cusp mirror structure can then be easily used for further manufacturing processes, for example for the manufacture of shield plates.

In a further preferred embodiment, the triple mirror structure is introduced into the surface of the strip material by means of a negative mold. A negative form is to be understood as a negative form of the triple mirror structure, for example the stamping structure of a stamp.

The triple mirror structure is preferably introduced into the surface of the strip material or shield plate by means of a stamp. The structure can be embossed, rolled or printed with the stamp. Particularly preferably, the negative mold is designed as a roller, with which the surface of the strip material or shield plate is at least partially rolled off. The roll width can be in a preferred example 0.05 m to 1 m, preferably between 0.1 and 0.5 m. If the roll width is smaller than the width of the shield plate or of the strip material, the surface may need to be rolled off several times in order to introduce the structures according to the invention in all areas which are to have retroreflective properties.

The negative form of the triple mirrors in a stamp or in a roller can be configured, for example, as protruding cube corners or as a "full-cube" structure, and it is particularly preferred here for the triple mirrors to be designed as outstanding cube corners from the negative mold. In a further embodiment of the method, it is preferred that the introduction of the triple mirror structure into the surface of the strip material or a shield plate and the separation of the shield plate from the strip material take place simultaneously. This can be done for example by a correspondingly designed negative mold. Furthermore, it is also conceivable that these steps are carried out individually and successively in any order. It is also explicitly conceivable and provided that only shield plates are produced from a strip material, in which then a triple mirror structure is introduced.

In an alternative embodiment, a shield plate is produced by means of an injection molding or die casting process. In the surfaces of the cavity of the injection molding tool in the areas in which the shield plate is to have retro-reflective properties, structures are introduced for the impression in the shield plate, which are complementary to those with the retroreflective structures according to the invention. In an impression of these structures then arise in the surface of the shield plate areas with retroreflective properties.

As materials for the Schildplatte all injection moldable materials such. thermoplastic or die-cast materials such as aluminum or aluminum alloys. In a further embodiment of the method, a coating is applied to the strip material or the shield plate. The coating is preferably applied by laminating and / or gluing and / or welding and / or spraying onto the strip material or the shield plate. In a preferred embodiment, the coating is formed from the air side of a mirror.

Furthermore, it can be provided that a legend is applied to the strip material or the board. It is possible that the legend is applied directly to the strip material or shield plate and the coating. It is preferred that the legend is plastically designed and colored. A coloring of a plastically designed legend can be carried out for example by a thermal transfer method. Furthermore, an edge region and / or a frame of a shield plate can be formed as a relief or as a plastic. Furthermore, it can also be provided that a separation of the shield plate from the strip material and the introduction of a plastically designed legend in a single process step are completed. Furthermore, it is also conceivable that the introduction of a legend is carried out in a single process step.

Further advantageous embodiments and further developments are specified in the following figures. However, the resulting respective features are not limited to individual figures or embodiments. Rather, one or more features of the above description may be combined with single or multiple features of the figures in addition to further developments.

Show: 1 to FIG. 2: the principle of a retroreflector with square mirror surfaces,

Fig. 9 a surface of a body with a triple mirror structure,

Fig. 10 to FIG. 13 a body with coating,

Fig. 14 and FIG. FIG. 15 shows a further triple mirror structure on the surface of a body and. FIG

Fig. 16 to FIG. 18 different variants of a shield.

In the following figures, the term "body" is to be understood as a shield and / or band material alike. FIG. 1 shows the principle of a retroreflector whose structure is used here as a triple mirror 1. The physical principle is based on the fact that an incident light beam L is reflected back to the light source independently of the angle of incidence. For the retroreflecting function of a triple mirror 1, three mirror surfaces 2, 4, 6 must be arranged perpendicular to one another. The vertical arrangement of the mirror surfaces 2,4,6 is here characterized by the spatial coordinate system with the axes XYZ. The mirror surfaces 2, 4, 6 are of square design, so that a triple mirror of the "full cubes" variant is shown here The retroreflective principle of the triple mirror 1 is schematically outlined here by the arrows L, which are to represent incident light beams In the retroreflectors known from the state of the art, which are based on total internal reflection on the surfaces of prismatic elements, the beam path shown in Fig. 1 lies in the transparent material of the body whose surfaces form the triple mirror 1.

In contrast, in the present invention, the in ig. 1 shown optical path outside the material of the body whose surfaces form the triple mirror 1, d. H . a body according to the invention does not show any back-surface but front-surface retroreflection from the air side of the body.

Again, it is expressly understood that the exterior surfaces of a prismatic element-based retroreflector based on total internal reflection, when illuminated from the air side, form retroreflective corner mirrors, even when the prismatic surfaces are mirrored. This is because the geometry of the body surface in which the prismatic surfaces are formed differs depending on whether they are viewed from within the body or from the air side of the body. A geometry in which retroreflection occurs is always possible only from one of the two half-spaces.

FIG. 2 shows a surface 8 of a body 10 which has a triple mirror 1. In this case, three mirror surfaces 2,4,6 are formed as an impression of a cube corner in the surface 8 and each have a triangular shape. The three mirror surfaces 2,4,6 are perpendicular to each other in the three spatial planes, which are spanned by the axes XYZ of the drawn coordinate system.

FIG. 3 shows a surface 8 of a body 10 in which a triple mirror 1 is introduced as an oblique impression of a cube corner. In this case, the three mirror surfaces 2,4,6 each have a triangular, albeit different triangular shape. To ensure the triple mirror function, it is not necessary for the triple mirror 1 to be symmetrical. It can also be asymmetrical, as shown for example in Figure 3, be formed. In this case, only one example is formed in FIG. A triple mirror 1 can also be designed asymmetrically in another way. By an asymmetrical formation of a Tripeispiegeis 1 in a surface 8 certain effects can be achieved, such as that varies the retroreflectivity of the surface 8 depending on the angle.

FIG. 4 shows a triple mirror 1 as in FIG. 2, which is introduced as a depression into the surface 8 of a body 10. The triple mirror 1 in this case has three mirror surfaces 2, 4, 6, which are arranged perpendicular to each other in the three spatial planes.

Figure 4 shows the arrangement of the Tripeispiegeis 1 as a depression in the body. From the section Z-Z, the depth T of the Tripeispiegeis 1 can be seen, with which this is introduced into the surface 8 of the body 10. The depth T of the triple playing gel extends from the surface 8 to the deepest point of the recess.

FIG. 5 shows the triple mirror 1 from FIGS. 2 and 4, which is introduced into the surface 8 of a body 10. The triple mirror 1 has six sides, which are marked with Si to S ₆ . The base G of the Tripeispiegeis 1 is formed by the sides Si, S ₂ and S ₃ .

FIG. 6 shows a triple mirror 14 which is formed protruding from the surface 8 of a body 10. In the surface 8 of the body 10 while a recess 16 is formed. In this recess 16, the mirror surfaces 2 ^λ , 4 ^λ and 6 ^{λ are} formed. These mirror surfaces do not adjoin one another. They are formed at right angles to each other only in the three spatial planes and thus provide a retroreflective function. Schematically Here, a light beam is shown, which is reflected by the three mirror surfaces 2 ^λ , 4 ^λ , 6 ^λ in the direction of the light source.

FIG. 7 shows a section through the body 10 from FIG. In the sectional view, the recess 16 is shown with the mirror surface T of the triple mirror. Here, it is also shown that the mirror surfaces of the triple mirror must be formed only as small areas of the surfaces of the recess in order to achieve the retroreflecting function of the triple mirror. Depending on the size and reflectance of the mirror surfaces, the degree of retroreflection can be influenced. The orientation of the mirror surfaces at right angles to each other in the three spatial planes is decisive for the triple mirror function. The mirror surfaces can have any shape.

Due to the danger that observers will be blinded by retroreflected light beams, in some applications it is desirable that not all the incident light be retroreflected, but only a portion. Furthermore, it may also be desired that a reflection takes place only in certain viewing angles. Due to the size of the mirror surfaces and the nature of the mirror surfaces, the degree of retroreflection can be adjusted. By smaller mirror surfaces 2 ^λ , 4 ^λ , 6 ^λ less light is retroreflected. Furthermore, it is also possible to design the mirror surfaces with only a partially reflective surface or only a little reflective surface, for example a matted surface, so that the incident light is only partially retroreflected. Furthermore, it can also be provided that the light is reflected with a certain angular spread, so that a viewer is not dazzled. For this purpose, for example, be provided to align the mirror surfaces with a deviation at right angles to each other.

FIGS. 8 and 9 show a depression with two triple mirrors. The mirror surfaces 2 ^λ , 4 ^λ , 6 ^λ are arranged at right angles to each other in three spatial planes and thereby have a retroreflective function. In addition to this, the mirror surfaces 18, 20, 22 in the recess 16 are arranged at right angles to each other in further spatial planes and represent a further triple mirror with retroreflecting function. To illustrate the function, light beams L are schematically drawn, which once consist of the triple mirror the mirror surfaces 2 ^λ , 4 ^λ , 6 ^λ are thrown back to a light source and once from the mirror surfaces 18,20,22.

FIG. 9 shows the depression 16 from FIG. 8 in section 7.-7. From this sectional view of the body 10 through the recess 16 it can be seen that the mirror surfaces 2 18 and 20 are formed in the recess 16 into it. In the sectional view, the other mirror surfaces 4 \ 6 \ 12 are not visible.

Furthermore, it is possible to apply a coating 24 to the body 10. Such a coating 24 is shown in FIG. The coating on the surface 8 of the body 10 is mounted so that the coating 24 covers the recesses 16 with the triple mirrors. In order to ensure the retroreflective function of the triple mirrors formed in the recess 16, the coating must be made transparent so that a light beam can reach the mirror surfaces.

In FIG. 11, a body 10 is shown in section, in which a depression 16 with a mirror surface T of a triple mirror is formed. A coating 26 is applied to the surface 8 of the body 10 so that the coating 26 also extends into the recess 16 and over the mirror surface T of the triple mirror. To ensure the retroreflective function of the triple mirrors, such a coating is made transparent.

FIG. 12 shows another possibility of superficially providing a body 10 with a transparent coating 28. In this embodiment variant, the coating fills the recesses 16, in which the triple mirror is configured on. An internal total reflection in the coating does not take place in this embodiment, since the transparent coating 28 is directly adjacent to the material of the body 10. As a result, the prerequisites for a transition from the transparent medium to an optically thinner medium with sufficiently different refractive indices are not given. An advantage of this embodiment is that the transparent coating in the recesses provides a reflection in a larger angular range, because the surface of the transparent coating usually causes a refraction of the incident light rays to the symmetry axis. With the transparent coating, which also fills the cavity between the individual mirror surfaces, Thus, retroreflection is possible in a larger angular range of incident light than without this coating arrangement.

FIG. 13 shows a body 10 with a surface 8 into which a triple mirror is formed as a depression 16 with three triangular mirror surfaces. This arrangement is shown in section. However, the mirror surfaces have uneven surfaces so that they have insufficient reflectivity. By the sectional view only the mirror surfaces 48 and 50 can be seen. The third mirror surface is not visible. The mirror surfaces additionally have a coating 30 which has been introduced into the depression 16 in order to produce the reflectivity of the mirror surfaces. It is conceivable to provide for such a coating, for example, a metallization such as aluminum, or a coating which forms a smooth surface when applied, which is suitable for reflection. It is advantageous in such an embodiment that in the production of the recess 16 with the mirror surfaces also imprecise tools can be used or the body 10 can be made of any material whose surface is not necessarily suitable for reflection. Only in a further manufacturing step, the mirror surfaces are processed or coated so that they are suitable for reflection afterwards. The choice of coating can be varied depending on the location. Thereafter, it is conceivable to apply metals, lacquers, paints or even just another surface treatment in the area of the mirror surfaces in order to produce or improve the reflectivity of the mirror surfaces. In FIG. 13, the insufficiently reflecting mirror surfaces 48, 50 have been coated with the coating 30 in order to compensate for unevenness. The surface of the coating 30 is reflective for the triple mirror function.

FIGS. 14 and 15 show a body 10 with a surface 8, into each of which a triple mirror structure consisting of individual triple mirrors 34 with triangular mirror surfaces is introduced. In FIG. 14, the individual triple mirrors are introduced into the surface 8 of the body 10 at a distance from one another. In contrast, in FIG. 15, the sides of the individual triple mirrors 34 adjoin one another directly. Depending on the desired site of use and the desired degree of retroreflection of a triple mirror structure, the density of the triple mirrors per area can be adapted. The more retroreflective mirror surfaces per surface applied, the greater the degree of retroreflection can be configured become . However, this degree of retroreflection does not depend only on the density of the triple mirrors on the surface. Rather, it can also be influenced by the degree of reflection of the individual mirror surfaces as already explained above. The degree of reflection can thus be adjusted by several factors.

FIG. 16 shows by way of example a motor vehicle license plate 38 with a legend 36. The illustrated license plate 38 from FIG. 16 is provided with a triple mirror structure with triangular mirror surfaces, shown here schematically in the enlargement 40, which are arranged in a metallic shield plate, which is e.g. , B. aluminum or an aluminum alloy, are introduced. The license plate 38 may also be provided with other triple mirror structures as described above. Here, by way of example only, such a shield 38 has on the surface a retroreflective structure according to the invention.

For the license plate 38 of Figure 16 may be provided on the one hand, that the visible in the enlargement 40 Tripelspielgelstruktur is introduced directly into the vehicle license plate 38.

In the following figures 17 and 18, two possible body variants for a license plate 38 a and 38 b are shown. In this case, on the one hand, a triple mirror structure consisting of the triple mirrors 42 can be introduced directly into a surface of the license plate 38 a, as shown in FIG. 17. Another embodiment of a license plate is shown in FIG. Here, the license plate consists of a plate blank 46, which is provided with a band material 44 with a triple mirror structure with the triple mirrors 42. LIST OF REFERENCE NUMBERS

1, 14, 34, 42, triple mirror

2,4,6,2 \ 4 \ 6 \

18,20,22,48,50 mirror surfaces

8 surface of a body

10 bodies

16 deepening

24,26,28,30 coating

36 legend

38,38a, 38b license plate

40 Magnification License plate

44 band material

46 Shield raw ling

L light beam

T depth of the triple mirror

G base area of the triple mirror

Si, S2, S3, S ₄ , S ₅ , S ₆ sides of the triple mirror

Claims

claims

A retroreflective shield (10, 38, 38a, 38b) having a triple mirror structure, wherein the triple mirror structure is a triple mirror

(1,14,34,42) comprising at least three mutually perpendicular mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) for retroreflection,

characterized in that

the triple mirror (1, 14, 34, 42) is designed as a recess (16) in a surface (8) of the plate (10, 38, 38a, 38b) and has mirror surfaces (2, 4, 6, 2 ', 4'). , 6 ', 18,20,22,48,50) forms, which are formed from the air side of SPIE ^¬ gelnd.

2. shield (10, 38,38a, 38b) according to claim 1, wherein the shield (10, 38, 38a, 38b) at least in the region of the mirror surfaces made of metal.

3. shield (10, 38, 38 a, 38 b) according to claim 1 or 2, characterized in that the mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) We in ^¬ sentlichen are triangular.

4. shield (10, 38, 38 a, 38 b) according to claim 1 or 2, characterized in that the mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) are quadrangular We ^¬ sentlichen, in particular square.

5. plate (10, 38, 38 a, 38 b) according to one of claims 1 to 4, characterized ge ^¬ indicates that the triple mirror (1,14,34,42) has a triangular Grund ^¬ area (G).

6. shield (10, 38, 38a, 38b) according to any one of the preceding claims, characterized in that the triple mirror (1,14,34,42) at least one side (Si, S2, S ₃ , S ₄ , S ₅ , S ₆ ) having a length in the range of 70 to 400pm.

7. shield (10, 38, 38 a, 38 b) according to one of the preceding claims, wherein the triple mirror structure has at least partially a microstructure.

8. shield (10, 38, 38 a, 38 b) according to one of the preceding claims, wherein the shield at least in the region of the mirror surfaces

(2,4,6,2 ^' , 4 ^' , 6 ^' , 18,20,22,48,50) having a coating from the air side (24,26,28,30) comprising.

9. shield (10, 38, 38 a, 38 b) according to claim 8, wherein the coating

(24,26,28,30) has means for light scattering.

10. shield (10, 38, 38 a, 38 b) according to one of the preceding claims comprising plastic and / or wood.

11. Shield (10, 38, 38a, 38b) according to one of the preceding claims, characterized in that the triple mirror structure at least partially has a plurality of triple mirrors (1,14,34,42).

12. shield (10, 38, 38 a, 38 b) according to claim 11, wherein the triple mirror

(1,14,34,42) are substantially adjacent to each other.

13. shield (10, 38, 38 a, 38 b) according to one of the preceding claims comprising a legend (36).

The shield (10, 38, 38a, 38b) of claim 13, wherein the legend (36) is colored.

15. shield (10, 38, 38 a, 38 b) according to claim 13 or 14, wherein the legend (36) is designed in relief and / or plastic.

16. A retroreflective tape material (10, 44) comprising a cusp mirror structure, wherein the cusp mirror structure is a cusp mirror

(1,14,34,42) comprising at least three mutually perpendicular mirror surfaces (2,4,6,2 ^' , 4 ^' , 6 ^' , 18,20,22,48,50) for retroreflection,

characterized in that the prismatic reflector (1,14,34,42) is formed as a recess (16) in a Oberflä ^¬ surface (8) of the strip material (10,44), and mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) forms, which are formed from the air side of a mirror, wherein the band material (10,44) has metal on ^¬ .

17, strip material (10,44) according to claim 16, wherein the strip material at least in the region ^¬ of the mirror faces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) of metal consists.

18, strip material (10,44) according to claim 16 or 17, characterized in that the mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) in ^¬ We sentlichen are triangular.

19, strip material (10,44) according to claim 16 or 17, characterized in that the mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48,50) in ^¬ We sentlichen quadrangular, in particular square, are.

20. strip material (10, 44) according to one of the preceding claims,

characterized in that the triple mirror (1,14,34,42) has a triangular base (G).

21. strip material (10, 44) according to one of the preceding claims,

characterized in that the prismatic reflector (1,14,34,42) at least one side (Si, S2, S3, S _4, S _5, S ₆₎ having a length in the range of 70 to 400pm.

22 strip material (10,44) according to any one of the preceding claims, wherein the triple mirror structure has at least partially a microstructure.

23, strip material (10,44) according to any one of the preceding claims, wherein the strip material (10,44) at least in the region of the mirror surfaces (2,4,6,2 ', 4', 6 ', 18,20,22,48 , 50) comprising a coating (24, 26, 28, 30) reflecting from the air side.

24, strip material (10,44) according to claim 23, wherein the coating

(24,26,28,30) has means for light scattering.

25 strip material (10,44) according to one of the preceding claims comprising plastic and / or wood.

26. strip material (10, 44) according to one of the preceding claims,

characterized in that the triple mirror structure at least partially has a plurality of triple mirrors (1,14,34,42).

27. strip material (10, 44) according to claim 26, wherein the triple mirrors

(1,14,34,42) are substantially adjacent to each other.

28. strip material (10, 44) according to one of the preceding claims,

characterized in that the strip material (10,44) is wound up.

29. strip material (10, 44) according to claim 28, characterized in that the strip material can be wound up as a coil.

30. A method of manufacturing a retroreflective shield having a triple mirror structure according to any one of claims 1 to 15, comprising at least one of the following steps:

Providing a strip material,

- Introducing the triple mirror structure in a surface of the strip material by embossing and / or hot stamping and / or rolling and / or printing

- Separating a shield plate from the strip material.

31. The method according to claim 30, characterized in that the strip material has a metallic layer at least on the surface into which the triple mirror structure is introduced.

32. The method according to claim 30 or 31, characterized in that the triple mirror structure is introduced by means of a negative mold in the surface (8) of the strip material.

33. The method of claim 31, wherein the negative mold is a stamp and wherein the surface (8) of the strip material is stamped or rolled at least in regions with the stamp.

34. The method of claim 30 or 31, wherein the negative mold is a roller, with which the surface of the strip material is at least partially rolled off.

35. The method according to claim 34, characterized in that the roller has a width of 0.5 to 1 m.

36. The method according to any one of the preceding claims, wherein a coating reflecting from the air side is applied to the strip material or the shield plate.

37. The method of claim 36, wherein the coating is applied by lamination and / or gluing and / or welding and / or spraying on the tape material or the shield plate.

38. The method according to any one of the preceding claims, characterized in that a legend (36) is applied to the strip material or the shield plate.

39. The method according to claim 38, characterized in that the legend is designed plastically.

40. The method according to claim 38 or 39, characterized in that the legend (36) is colored, in particular by means of a Thermotrans- ferverfahren.