Abstract:
An identification plate, in which at least one security sign is arranged within the contours of a cover layer. As a result, the security sign is embedded in the cover layer and thus becomes an integral component of the identification plate. Such a security sign can no longer be removed from the identification plate. The identification plate according to the invention thus offers as much protection against manipulation as possible.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates to an identification plate, preferably to a number plate for motor vehicles, having an identification plate body, which has text provided on it, and at least one security sign, characterized in that the at least one security sign is arranged within the contours of the identification plate body. The invention furthermore relates to a method for producing an identification plate having as identification plate body, which is formed of at least one cover layer and at least one further layer, and at least one security sign is provided, characterized in that the at least one security sign is molded into the identification plate body. 
     2. Prior Art 
     In order to counteract manipulation and thefts of identification plates, especially of number plates on motor vehicles, the identification plates are provided with security features, which are also referred to as originality features or authenticity features in the art. Known are a wide variety of such security features. One example is security signs in the form of stickers with at least one hologram. Such security signs are adhesively bonded to the identification plate from the outside. The risk here is that the stickers are removed. While such security signs have been designed such that they cannot be removed without being destroyed, it has become clear that there are methods for occasionally removing security signs from the identification plate in a destruction-free manner. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is based on the object of providing an identification plate, preferably a number plate for a motor vehicle, and a method for producing it, whereby the protection against manipulation is improved in a simple manner. 
     An identification plate for achieving the object is an identification plate, preferably a number plate for a motor vehicle, having an identification plate body, which has text provided on it, and at least one security sign, characterized in that the at least one security sign is arranged within the contours of the identification plate body. Accordingly, provision is made for the at least one security sign to be arranged within the contours of the identification plate body of the identification plate. As a result, the at least one security sign is no longer adhesively bonded to the identification plate but is instead embedded entirely or at least partially in said identification plate. As a result, the at least one security sign is integrated in the identification plate, for example. Hence, it can no longer be removed from the identification plate. 
     The at least one security sign is preferably embedded in the identification plate body, especially in the cover layer thereof. One way in which this can be done is that the at least one security sign is located entirely in the interior of the identification plate body or the cover layer by being surrounded on all sides by the material in particular of the cover layer. Another way is that the at least one security sign can be embedded in the identification plate body such that a face of the respective security sign is exposed, in particular terminates flush with an adjoining face of the identification plate body. In that case, an opposite face and the side faces of the respective security sign are surrounded by the material of the identification plate body. Here, the respective security sign is practically located within a depression or cutout in the identification plate body, in particular its cover layer, which depression or cutout corresponds to the dimensions of the security sign. If the at least one security sign is embedded in this manner into the cover layer, the latter does not need to be transparent. 
     In one preferred embodiment of the identification plate, where a security sign is arranged entirely in the interior of the identification plate body of the cover layer, provision is made to form the cover layer from two plies which lie one above the other, with the respective security sign being arranged between the cover layer plies such that it is embedded on all sides in the cover layer. 
     If the at least one security sign is embedded in the cover layer such that one face of the security sign terminates flush with the adjoining face of the cover layer, the exposed face of the respective security sign can be arranged on a visible front side of the cover layer, but also on a rear side of the cover layer. In the latter case, provision is made for that face of the respective security sign that is not covered by the material of the cover layer to be covered by another layer on the rear side of the cover layer. In the case of the exposed face of the respective security sign that terminates flush with the front side of the cover layer, said face can also be covered, either by way of a protective film or a protective lacquer on the front side of the cover layer or a reflection layer arranged over the front side of the cover layer, in particular a retroreflective film. 
     One preferred embodiment of the invention provides for the respective security sign to have a carrier, in particular a plate-like carrier, having at least one security feature. In principle, the security feature can have any desired form. However, provision is preferably made for the security feature to be in the form of a hologram. However, it is also conceivable that the hologram forms the entire security sign. In the case of a security sign of this type, which is in the form of a hologram or at least has a hologram, the arrangement within the contours in particular of the cover layer, especially the partial or complete embedding and/or integration in the cover layer, results in an identification plate, especially a number plate for a motor vehicle, that cannot be manipulated. 
     A method for achieving the object is a method for producing an identification plate having as identification plate body, which is formed of at least one cover layer and at least one further layer, and at least one security sign is provided, characterized in that the at least one security sign is molded into the identification plate body. In this method, the identification plate, especially the number plate for a motor vehicle, is provided with the at least one security sign by way of molding into the cover layer. This can take place in a particularly simple manner during the production of the cover layer. The respective security sign serves here practically as a “lost shell” in the production of the cover layer which is effected by way of molding. 
     In a preferred development of the method, provision is made for the respective security sign to be embedded between two plies of the cover layer. To this end, a first ply of the cover layer is molded, the at least one security sign is placed on it, and the second ply of the cover layer is molded over the first ply and the security sign. The respective security sign can be placed onto the first ply of the cover layer before the latter has completely cured. There is also no need for the first ply of the cover layer to be cured by the time the second ply of the cover layer is molded onto the first ply. In that case, the second ply is applied onto the first ply “wet on wet”, as it were, and this brings about a homogenous connection between the two plies of the cover layer. This brings about irreversible complete embedding of the at least one security sign in the cover layer, as a result of which the at least one security sign is integrated in the cover layer physically and mechanically. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred exemplary embodiments of the invention will be explained in further detail below by reference to the drawing, in which: 
         FIG. 1  shows a perspective detail of an identification plate with greatly enlarged thicknesses of the individual layers thereof. 
         FIG. 2  shows a cross section through a second exemplary embodiment of the identification plate with, again, greatly enlarged thicknesses of the individual layers. 
         FIG. 3  shows a cross section through a third exemplary embodiment of the identification plate analogously to  FIG. 2 . 
         FIG. 4  shows a cross section through a fourth exemplary embodiment of an identification plate with, again, greatly enlarged thicknesses of the individual layers. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The figures show only a few different exemplary embodiments of an identification plate, specifically in particular of a number plate for motor vehicles. The identification plate largely consists of plastic. In addition, a preferably flexible identification plate body  10  is formed of a plurality of plies or layers. The identification plate body  10  has individual items of text which are preferably printed on a front face  11  of the identification plate body  10  which forms the front side of the identification plate. The text can also be made up of digits which are adhesively bonded thereto or of other graphics. 
     Furthermore, the identification plate has what is referred to as a security feature, which is formed, in the exemplary embodiment shown, as a plate-type security sign  12 . If appropriate, the identification plate can also have a plurality of security signs  12 . The security sign  12  can have any desired dimensions and areas. In the exemplary embodiment shown ( FIG. 1 ), the security sign  12  has a rectangular area. The security sign  12  is formed from a carrier, from which it obtains its plate-type form, and at least one hologram (not shown in the figures) or another security feature. The security sign  12  can also have a plurality of different security features. 
     The invention makes provision for the at least one security sign  12  to be assigned to the identification plate body  10 , in particular to be placed in the identification plate body  10 , such that it is located within the contours of the identification plate body  10 . Accordingly, and in contrast with the security sign which is adhesively bonded thereto, the security sign  12  does not protrude from any face of the identification plate body  10 . The at least one security sign  12  is preferably integrated in the identification plate body, specifically in a manner such that it is embedded in the identification plate body  10 , i.e. is located entirely in the interior of the identification plate body  11  by being surrounded completely by the material of the identification plate body ( FIGS. 2 to 4 ), or a visible face  14  of the security sign  12  terminates flush with the front face  11  of the identification plate body  10  and, as a result, the face  14  of the security sign  12 , which forms part of the front face  11  of the identification plate, is not surrounded or covered by the material of the identification plate body  10  ( FIG. 1 ). 
       FIG. 1  shows a perspective view of a section of the identification plate with a part of the identification plate body  10  and of the security sign  12  that is arranged within the contours thereof. The identification plate body  10  of the identification plate has a cover layer  15  which forms the visible front face  11  of the identification plate, arranged behind it an intermediate layer  16 , a reflection layer  17 , a carrier layer  18 , an adhesive layer  19  and a protective liner  20  on the rear side  21  of the identification plate body  10 . The protective liner  20  is removed in order to adhesively bond the identification plate for example to a body part of a vehicle such that it is not part of the identification plate body  10 . In the identification plate body  10  shown in  FIG. 1 , reflection means, which are glass spheres in the illustrated exemplary embodiment, are embedded in the cover layer  15  and the intermediate layer  16 . The glass spheres  22  are embedded between the cover layer  15  and the intermediate layer  16 . 
     In the illustrated exemplary embodiment, the security sign  12  is placed into the front face  11  of the cover layer  15  of the identification plate body  10 . Here, the security sign  12  is embedded in the cover layer  15 , specifically in a manner such that the vertical side faces and the rear face of the security sign  12 , which faces the glass spheres  22 , are covered by the material of the cover layer  15 . The visible face  14  of the security sign  12 , however, which terminates flush with the front face  11  of the identification plate, is not covered by the material of the cover layer  15 . Although in this manner the security sign  12  is arranged in the cover layer  15  and is connected to the material thereof at the side faces and the rear face, the visible face  14  of the security sign  12  is left exposed by the cover layer  15 . As a result, the cover layer  15  does not need to be transparent in order to be able to read the security sign  12 . Since, owing to the security sign  12  being embedded in the cover layer  15 , the visible face  14  terminates flush with the front face  11  of the cover layer  15 , it is impossible to separate the security sign  12 , which is embedded in the cover layer  15 , from the identification plate, specifically the identification plate body  11 . 
     The abovementioned embedding of the security sign  12  in the identification plate body  10  can also be present in identification plate bodies having a different structure, in particular other reflection bodies or even no reflection bodies and fewer layers, in the simplest case only the cover layer  15 , the adhesive layer  19  and the protective liner  20 . 
       FIG. 2  shows a number plate for a motor vehicle having an identification plate body  23 , in which a security sign  24  is embedded at a different location. The identification plate body  23  has a transparent, in particular clear, cover layer  25  with a visible front face  26 , on which individual items of text is provided. Located behind a rear face  27  of the cover layer  25  is an adhesive lacquer layer  28 , and behind this a spacer lacquer layer  29  to which an aluminum vapor deposit  30  is assigned on the rear, and an adhesive layer  31  which forms the rear of the identification plate body  23 . In the case of the identification plate shown here, up to the point when the identification plate body  23  is adhesively bonded to a part of the motor vehicle, the free rear of the adhesive layer  31  also has applied to it a protective liner  32  or the like. Here, too, glass spheres  33 , in particular glass microspheres, are embedded in the identification plate body  23 , specifically between the adhesive lacquer layer  28  and the spacer lacquer layer  29 . 
     In the case of the identification plate body  23 , the security sign  24 , which is preferably in the form of a hologram, in particular a hologram that is assigned to the carrier  13 , is also arranged in the cover layer  25 . In the case of the illustrated identification plate, the security sign  24  is located in the rear face  27  of the cover layer  25  which abuts the adhesive lacquer layer  28 . The security sign  24  is embedded in the cover layer  25 , wherein a rearward face  35  of the security sign  24  terminates flush with the rear face  27  of the cover layer  25 . This face  35 , which is not covered by the cover layer  25 , is covered by the adhesive lacquer layer  28 . As a result, in the case of the identification plate shown, the security sign  24  is covered completely, in part by the cover layer  25  and in part by the adhesive lacquer layer  28 . In order that the security sign  24 , which is located behind the front face  26  of the cover layer  25 , is visible from the front side of the identification plate, the cover layer  25  consists of a completely see-through, in particular transparent, material, in particular plastic. 
       FIG. 3  shows an identification plate having an identification plate body  37 , which has the same structure as the identification plate body  23  from  FIG. 2 . Therefore, identical reference numbers are used for those parts of the identification plate body  37  which correspond to the identification plate body  23  in  FIG. 2 . 
     Located in the identification plate body  37  is a security sign  36  which can be of the same form as the security sign  24 . The security sign  36  is also located completely in the interior of the identification plate body  37 , with the security sign  36  being placed completely in the interior of the cover layer  25  in the exemplary embodiment shown ( FIG. 3 ). In the case of the identification plate body  37  of  FIG. 3 , the security sign  36  is completely surrounded by the material of the cover layer  25  by way of the security sign  36  being arranged in the interior of the cover layer  25  at a distance below the front face  26  thereof. The security sign  36  is likewise spaced apart from the rear face  27  of the cover layer  25 . In the exemplary embodiment shown, the security sign  36  is located eccentrically in the cover layer  25 , with the distance from the security sign  36  to the front face  26  being less than to the rear face  27  of the cover layer  25 . However, the security sign  36  can also be arranged at a greater or smaller distance below the front face  26  of the cover layer  25 , specifically in a manner such that the security sign  36  is surrounded on all sides by the material of the cover layer  25 . 
       FIG. 4  shows a further exemplary embodiment of an identification plate, with the identification plate body  38  of which having a simplified structure. This identification plate body  38  has only one front cover layer  39 , which has text on it and is transparent, preferably clear, and an adhesive layer  40  arranged behind it, in particular a pressure-sensitive adhesive layer. Provided behind the adhesive layer  40  is a protective liner  41  which is removed before the identification plate is adhesively bonded to a part of a vehicle. 
     In the case of the shown identification plate, the security sign  42  is embedded completely in the cover layer  39  by being located between the front face  43  and the rear face  44 . However, the security sign  42  can also be embedded at another location in the cover layer  39  than that shown in  FIG. 4 , specifically in a manner such that a face of the security sign  42  terminates flush with the front face  43  or the rear face  44  of the cover layer  39 , as is shown in the exemplary embodiments of  FIGS. 1 and 2 . 
     The identification plate shown in  FIG. 4  can also have an identification plate body  38  whose front face  43  is covered by a reflective coating, in particular a reflective film. In the case where the face of the security sign  42  terminates flush with the front face  43  of the cover layer  39 , this face of the security sign  42  is then covered by the reflective film. 
     The invention is also suitable for identification plates of any other construction, in particular those that have a grid of prisms, in particular microprisms, instead of the glass spheres  22  or  33 . 
     The method according to the invention will be explained in more detail below with reference to  FIGS. 1 to 3 . 
     The respective security sign  12 ,  24  or  36  is integrated in each case into the cover layer  15  or  25  by being molded into the cover layer  15  or  25 . In the case of the identification plate body  10 , the security sign  12  is placed at an appropriate location onto a firm substrate, onto which the material of the cover layer  15  is molded. Subsequently, the material of the cover layer  15  is applied to the substrate and in the process the security sign  12  is overmolded by the material of the cover layer  15 . This leads to the security sign  12  being embedded in the cover layer  15 , wherein owing to the face  14  of the security sign  12 , which is located on the support, terminates flush with the front face  11  of the cover layer  15 , which is molded onto the substrate. 
     In the identification plate having the identification plate body  23  of  FIG. 2 , the material of the cover layer  25  is applied over the whole area of a firm substrate, specifically right up to a specified layer thickness. Subsequently, the security sign is placed into the not yet cured cover layer  25  and pressed into the still liquid material of the cover layer  25 , such that the rearward face  35  of the security sign  24  terminates flush with the rear face  27  of the cover layer  25 . 
     In order to produce the identification plate having the identification plate body  37  of  FIG. 3 , the process includes molding the cover layer  25  in two steps. To this end, the cover layer  25  of the identification plate body  37  is formed from two plies, with the security sign  36  being arranged between the plies and thus being embedded completely in the cover layer  25 . For this purpose, first a first part, specifically a ply, of the cover layer  25  is molded onto a firm, level substrate. Placed onto this first ply is the security sign  36  while the material of the cover layer  25  is at least partially still in the liquid state. Subsequently, the second part, specifically the second ply, of the cover layer  25  is molded onto the first ply. In this manner, the security sign  36  is embedded completely between the two successively produced plies of the cover layer  25 . The various plies for forming the cover layer  25  are molded wet-on-wet one above the other such that a homogeneous cover layer  25  with embedded security sign  36  is produced after curing. 
     LIST OF REFERENCE NUMBERS 
     
         
           10  identification plate body 
           11  front face 
           12  security sign 
           13  carrier 
           14  face 
           15  cover layer 
           16  intermediate layer 
           17  reflection layer 
           18  carrier layer 
           19  adhesive layer 
           20  protective liner 
           21  rear 
           22  glass sphere 
           23  identification plate body 
           24  security sign 
           25  cover layer 
           26  front face 
           27  rear face 
           28  adhesive lacquer layer 
           29  spacer lacquer layer 
           30  aluminum vapor deposit 
           31  adhesive layer 
           32  protective liner 
           33  glass sphere 
         
           34 
         
           35  face 
           36  security sign 
           37  identification plate body 
           38  identification plate body 
           39  cover layer 
           40  adhesive layer 
           41  protective liner 
           42  security sign 
           43  front face