WO2012101126A1

WO2012101126A1 - Safety/security system for a glazing assembly, glazing assembly with a safety/security function and method for detecting mechanical or thermal stress on a planar glazing element

Info

Publication number: WO2012101126A1
Application number: PCT/EP2012/051057
Authority: WO
Inventors: Udo WEINAND
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2011-01-24
Filing date: 2012-01-24
Publication date: 2012-08-02
Also published as: EP2668643A1; EP2668643B1; DE102011003073B4; DE102011003073A1

Abstract

The invention relates to a glazing assembly (10) with a safety/security function, comprising a planar glazing element (20) and an optical waveguide structure (30) with an optical filter element (32). The optical waveguide structure (30) is mechanically connected to the glazing element (20) in order to effect a change to an optical characteristic of the optical waveguide structure (30) when the planar glazing element (20) is exposed to mechanical stress and in addition in order to effect a change to an optical characteristic of the optical waveguide structure (30) when the planar glazing element (20) is exposed to thermal stress.

Description

Security system for a glazing arrangement, glazing arrangement with safety function and method for detecting a mechanical or thermal stress of a planar glazing element

description

The present invention relates to a glazing arrangement with safety function, to a safety system for a glazing arrangement and to a method for detecting a mechanical or thermal stress of a planar glazing element. In particular, the present invention relates to a concept for monitoring a sheet glazing element, e.g. a glass pane or a laminated glass pane, in order to detect a mechanical or thermal stress by an external action on the planar glazing element early or promptly. As a result, an attempted manipulation of the planar glazing element, for example during a break-in attempt, can be detected almost in real time and a corresponding alarm can be triggered at an early stage. Likewise, the concept according to the invention can be applied to flat glazing elements which, when used, exhibit strong mechanical and / or thermal stresses, such as e.g. on windshields in an airplane cockpit, on trains or other vehicles, to detect early excessive mechanical or thermal stress on the glazing elements and to avoid mechanical failure due to sudden, unforeseen breakage of the planar glazing element.

In many areas, so-called safety glass is used to provide either the glazing, eg laminated glass or laminated safety glass, with as much intrusion-resistant effect as possible or unauthorized physical access to areas secured by safety glass, eg displays of jewelers, showcases etc., as safe as possible. In addition, so-called passive glass breakage detectors are also used for the respective glazing elements, which are arranged on the glazing to be monitored and detect a glass breakage or a physical destruction of the glazing element. In this context, different DIN standards refer to so-called resistance classes (DIN V ENV 1627), which, for example, consider resistance times, ie the time that a product withstands burglary, the types of perpetrators and the modus operandi. Furthermore, there are test standards (DIN EN 356) for antiperspirant glazings, ie to what extent the glazings are burglary-resistant, puncture-resistant or attack-inhibiting. Furthermore, safety glass is also used in areas such as windshields in aircraft cockpits, high-speed trains or other vehicles that are exposed to very strong thermal and in particular mechanical stresses.

A disadvantage of the methods known hitherto in the prior art is that, for example, a break-in attempt is detected only when mechanical damage or destruction of the monitored glazing element occurs. If, for example, an intrusion attempt causes the safety glass to be changed in stability by means of a gas burner or cutting torch until the safety glass finally melts, a potential burglar can relatively quickly reach the valuables exposed behind the safety glazing without an alarm from a passive glass breakage detector is issued. Furthermore, previously had to identify a heat source in the security area aufwand ige thermal imaging cameras are used, a timely Wärmein formation should be obtained. In order to obtain the most comprehensive detection of burglary, different surveillance concepts therefore had to be combined according to the prior art in order to detect both mechanical and thermal effects on safety glazings. This leads to their realization to a high cost and thus also high costs.

Starting from this prior art, the object of the present invention is to provide a concept for a glazing arrangement with a safety function, by means of which a detection of acting on a planar glazing element mechanical and / or thermal stress or load early and possible lent in Real time can be detected.

This object is achieved by a safety glazing system according to claim 1, by a glazing arrangement with safety function according to claim 18, by a method for detecting a mechanical or thermal stress of a flat Vergl asungsel ements according to claim 27 and by a computer program according to claim 32.

The core idea of the present invention is to mechanically arrange an optical waveguide structure with an optical filter element, such as a fiber Bragg grating or Bragg filter, on the planar glazing element such that an optical property of the glazing element is due to mechanical or thermal stress Optical waveguide structure and in particular of the optical filter element is changed. A mechanical connection between a glazing element and a Optical waveguide structure may be formed, for example, positive, cohesive or cohesive. Thus, in particular, according to the invention, use is made of the fact that, in the case of the Bragg filter arranged in an optical waveguide structure, a strain influence and / or a refractive index change of the material of the Bragg filter occurs due to mechanical or thermal stress of the planar glazing element, so that the center frequency of the Bragg Filter as a variable, optical property of the optical waveguide structure according to the mechanical or thermal action changes. Such a change in the center frequency of the Bragg filter can now be detected relatively easily with optical detection elements coupled to the optical waveguide structure, wherein the magnitude of the change in the center frequency Δλ / λο can be assigned the degree of mechanical and / or thermal stress of the planar glazing element. According to the invention can thus be concluded by evaluating the optical property of the Bragg filter in the optical waveguide structure directly on a manipulation, for example by a burglar, the planar glazing element. Furthermore, in order to increase the detection reliability, "normal" thermal or mechanical effects, such as temperature changes due to ion irradiation, on the planar glazing element can be taken into account in the evaluation of the optical property of the optical waveguide structure For example, if multiple Bragg filters are used, they may have different filter center frequencies or filter center wavelengths, for example, to further provide spatial resolution of the ones to be monitored to receive monitoring, surface glazing element acting mechanical or thermal stresses, as will be explained in detail below.

The optical waveguide structure with the optical filter element or the optical filter dementer can now, for example, on a multi-layer, planar glazing element, for. B. a laminated glass arrangement, are arranged, wherein the optical waveguide structure in a glass capillary, a milled groove or subsequently mounted on the safety glass in capillaries and with the monitored surface glazing element at least partially form-, force and / or substance conclusive is bound.

With regard to the mechanical connection of the glazing element with the optical waveguide structure, it is pointed out that the optical waveguide structure is either already at the production of the glazing element in or on the same mechanically, ie, form, force and / or material fit, can be arranged or can be subsequently arranged on the glazing element in subsequently mounted recesses or recesses (eg capillary or groove). If, for example, the light waveguide structure with the optical filter elements is already integrated in the material of the glazing element during the production of the glazing element or fixed within one of several layers of a laminated glass arrangement, for example using a transparent adhesive, the optical waveguide structure can be shaped, force and / or readily or cohesively arranged on the glazing element, so that a mechanical stress or deformation (eg elongation) of the glass material is transmitted directly to the optical waveguide structure and the optical filter elements located therein. Similarly, a thermal stress on the glazing element, ie a temperature increase, is transmitted directly to the optical waveguide structure and the optical filter elements located therein.

In a subsequent arrangement of the optical waveguide structure on the glazing element, a distinction must be made as to whether the optical waveguide structure can be inserted into an outwardly accessible recess (eg a milled groove) and connected substantially completely to the glazing element using an adhesive or if the optical waveguide structure is pushed in in a glass capillary provided in the glazing element substantially only at the end points (ie at the entry and exit point of the optical waveguide structure on the glazing element) can be mechanically connected to the same. In the second case, a mechanical stress, e.g. in the form of an elongation of the glazing element, as a relatively uniform elongation of the optical waveguide structure between the two fixed end points. Thus, in comparison with a complete mechanical connection of the optical waveguide structure with the glazing element, the detection of an elongation of the optical waveguide structure and thus of the glazing element continues to be possible, but without an exact spatial allocation of the location of the acting mechanical stress.

In contrast to a mechanical stress is in a thermal stress of the glazing element in the case of a selective connection of the optical waveguide structure with the glazing element nevertheless a spatial assignment of the location of the applied thermal stress possible, as with heating of the glazing element only corresponding sections of Lichtwel 1 heat conductor structure and thus heat only certain Bragg filter elements and change their optical filter property. By monitoring the optical property of the optical filter elements designed as Bragg filters, externally supplied heat or high pressure, as may be the case, for example, in an attempted break-in, can be determined by the resulting mechanical strain (or compression) of the planar glazing element to be monitored. ments and thus also the mechanically connected Lichtwel lenleiterstruktur detected very quickly and almost in real time and an electronic alarm are triggered to indicate the manipulation of the monitored, planar glazing element. In addition, the optical waveguide structure arranged on the planar glazing element to be monitored can be used simultaneously with the optically series-connected Bragg filters as a rupture sensor, since only signals from those filter elements (having a sufficient amplitude) are reflected back Optical waveguide structure at positions (in Lichteinkoppelrichtung) are located in front of the break, while reflection signals from one or more Bragg filters fail behind the breakage.

The procedure according to the invention for implementing the glazing arrangement with safety function can now be used extremely advantageously for monitoring a flat glazing element, since the optical waveguide structure can be used with the optical filter elements designed as Bragg filters for feeding an optical signal into the optical waveguide structure, and by evaluating the Information about a mechanical and / or thermal stress of the planar glazing element to be monitored can be determined directly and almost in real time from optical signals reflected or transmitted by the optical filter elements. Thus, according to the invention, compared with the other methods known in the prior art with only one sensor arrangement, it is possible to detect both a heat action and an elongation or breakage (or kink) of the planar glazing element to be monitored, whereby the respective state of the component to be monitored, Information describing the planar glazing element can be read out directly and almost in real time in the form of a change in the optical property of the optical waveguide structure. The erfmdungsgemäße glazing assembly with security function is thus everywhere used where valuables, goods or other items to be secured against unauthorized access or access, eg jewelers, banks, department stores, etc. In addition, mechanical stresses in heavily used discs, such as Windscreens in aircraft cockpits, trains or other vehicles, can be detected in time. Preferred embodiments of the present invention are described below

Reference to the present drawings explained in more detail. Show it:

Fig. La-b Prinzipdarstel ments in a plan view and a sectional view of a glazing assembly according to the invention with security function according to an embodiment of the present invention;

Fig. 2a-c is a schematic diagram of a Li chtwellenleiterstruktur with an optical

Filter element for the inventive safety feature glazing assembly according to an embodiment of the present invention; a schematic diagram of a glazing assembly with safety function according to another exemplary embodiment of the present invention; a schematic diagram of a security system for a glazing assembly according to another embodiment of the present invention; and

Fig. 5 is a schematic flow diagram of a method according to another

Exemplary embodiment of the present invention.

Before the present invention is explained in more detail below with reference to the drawings, it is pointed out that identical, functionally identical or equivalent elements in the different figures are provided with the same reference numerals, so that the description of the elements shown in the different embodiments with the same reference numerals interchangeable with each other or can be applied to each other.

In the following, the basic structure and principle of operation of a glazing arrangement 10 with safety function according to a first exemplary embodiment of the present invention will now be described with reference to the basic configuration of an optical waveguide structure 30 shown in FIGS. 2a-c an optical filter element 32 by way of example.

As shown in FIG. 1 a, the glazing arrangement 10 has a planar glazing element 20. The planar glazing element can, for example, be a single-layered or multi-layered transparent material, eg glass, plastic or a composite material, exhibit. Thus, for example, the flat glazing element 20 for safety glazing as laminated glass can have a combination of glass and transparent plastic films. An optical waveguide structure 30 having an optical filter element, for example in the form of a fiber Bragg grating or an optical Bragg filter, is now arranged on the planar glazing element 20. The optical waveguide structure 30 thus has an optical waveguide section 34 and the optical filter element 32. In addition, the light wave 1 has an input coupling input 36 for coupling an optical signal S] into the optical waveguide structure 30. Furthermore, the optical waveguide structure 30 also has an additional optical waveguide section 34, even after the optical filter element 32, wherein the further light path 1 is provided for example at an output coupling 38 on an arbitrary side surface, eg an opposite side surface of the planar glazing element 20 Decoupling of a passing through the optical filter element 32 optical signal Sjr is performed. As shown in Fig. L from now on, the optical waveguide structure 30 is disposed within the material of the surface Vergl asungselements 20. As shown in Fig. Lb, the sheet-like glazing element 20, for example as a laminated glass, a plurality of individual layers 20-1, ..., 20-5 (20-n), wherein the optical waveguide structure 30, for example, in a small capillary or a milled groove in the second glazing pane 20-2 (behind the first pane 20-1) of the planar glazing element 20 is arranged.

However, this arrangement of the optical waveguide structure 30 shown in FIG. 1a-b on the planar glazing element 20 can only be regarded as exemplary. Thus, the optical waveguide structure 30 can generally be introduced into a recess or recess 40 within the material of the planar glazing element 20 or else on a surface of the planar glazing element 20. Of course, in the production of the planar glazing element 20 corresponding recesses or recesses may be provided on or in the glazing element 20 for insertion or insertion of the optical waveguide structure in advance. The optical waveguide structure 30 can now be fastened, for example by means of a transparent adhesive material or another fastening material in the provided recess 40.

Furthermore, it is also possible to subsequently arrange the optical waveguide structure 30 on a glazing element 20. In a subsequent installation in a recess or recess 40 (or depression) provided on the glazing element 20, for example, subsequently, the optical waveguide structure 30 can be fixed, for example, by means of a foil (not shown in FIG flat glazing Sung elements 20 is glued to the surface of the planar glazing element 20 at least in the region of the recesses 40 for the optical waveguide structure 30.

With regard to a localized resolution of a mechanical load on the glazing element 20, it is pointed out that this mechanical stress can be detected in a spatially resolved manner only with the use of a plurality of Bragg filter elements 32 at those regions of the glazing element 20 where a fixed or frictional mechanical connection of the glazing element 20 is detected Optical waveguide structure 30 is present with the optical filter elements 32 on the glazing element. In this regard, reference is made to the detailed embodiments in FIG. 4, which are applicable to all embodiments of the present invention.

In connection with the optical waveguide structure 30 illustrated in FIG. 1a-b, it is pointed out that this has only one optical filter element 32 for the purpose of simplifying the description. In the following description it will become clear that a plurality of optical filter elements may be arranged in the optical waveguide structure 30, the optical waveguide structure 30 also being arranged along substantially arbitrarily shaped, e.g. Meander-shaped, recesses 40 may be arranged in the planar glazing element 20. Furthermore, further optical waveguide structures (not shown in FIG. 1a-b) with respective coupling inputs and optional coupling inputs can be arranged separately in the planar glazing element 20.

The optical waveguide structure (s) 30, each with a plurality of optical filter elements 32, can now be arranged on the planar glazing element 20 in order, for example, to distribute an array of sensor elements (in the form of the optical filter elements 32) distributed over the base area of the array element in a grid to obtain planar glazing element 20. Such an arrangement of the optical waveguide structure 30 on the planar glazing element 20 will be discussed in more detail below with reference to FIG. 3.

It should also be noted that the rectangular and straight shape of the surface of the planar glazing element 20, as shown in the figures, is to be regarded merely as an example. The inventive concept is particularly applicable to arbitrarily shaped and curved surfaces of a planar glazing element 20. As shown in Fig. Lb now shown, the optical waveguide structure 30 with the optical filter element 32, for example, a diameter "a" of 80-200 μηι, so that, for example, provided in the planar glazing element 20 recess 40 dimensions with a width "b" and a height "c" of, for example, 200-650 μm may have to accommodate the optical waveguide structure 30. In a possible space between the optical waveguide structure 30 and the side walls of the recess 40 may be, for example, a transparent adhesive or other transparent bonding material (not shown in Fig. La-b) for filling any voids, for maintaining the mechanical stability and for fixing to the glass (Kraftschi uß) be provided, as far as the adhesive can be introduced into the recesses.

The optical waveguide structure 30 with the optical filter element 32 is now arranged on the planar glazing element 20 so that any mechanical and / or thermal stresses acting on the planar glazing element 20 are transmitted as directly as possible to the optical waveguide structure 30 with the optical filter element 32 be passed on at least to a degree. That is, the optical waveguide structure 30 is mechanically disposed on the planar glazing element 20 so that mechanical or thermal stress, i. the action of an elevated temperature or an external mechanical force on the planar glazing element 20 causes a change in the optical property of the optical waveguide structure 30 and in particular of the optical filter element 32 of the optical waveguide structure 30. For this purpose, it is therefore necessary for the optical waveguide structure 30 to be sufficiently thermally and / or mechanically coupled to the planar glazing element 20 in order to ensure sufficient heat and / or force transmission from the planar glazing element 20 to the optical waveguide structure 30. By mechanical forces are meant, for example, tensile, compressive, impact, shock or bending loads. To provide a thermal coupling of the optical waveguide structure 30 with the planar glazing element 20, it is only to be noted that the planar glazing element 20 and the optical waveguide structure 30 are arranged sufficiently close to each other or in (thermal) contact with each other. In order to further transmit mechanical stresses of the planar glazing element 20 to the optical waveguide structure 30 to a sufficient degree, a corresponding mechanical connection, e.g. a force, shape and / or material connection, the optical waveguide structure 30 may be provided with the optical filter element 32 on the planar glazing element 20.

Reference will now be made below, with reference in particular to FIGS. 2a-c, to the way in which the relationship between a mechanical and / or thermal load is investigated. tion of the planar glazing element 20 and a change in an optical property of the optical waveguide structure 30 and in particular the optical filter element 32 of the optical waveguide structure 30, which is present for example in the form of a Bragg filter is obtained.

As shown in FIGS. 2a-c, the optical filter element 32 is formed, for example, as a fiber Bragg grating or optical Bragg filter. The Bragg filter 32 is an optical interference filter inscribed in the glass fiber core of the optical waveguide structure 30. Wavelengths of the optical signal S] (with the power distribution Pi) coupled into the optical waveguide structure 30 which lie within the filter bandwidth around the center bandwidth β of the Bragg filter are (at least for the most part) reflected back and yield the reflected signal SRI with the Power distribution PRI.

The optical waveguide structure 30 in the form of an egg nmodenglasfaser thus has a highly transparent glass fiber core 30-1 having the refractive index n ₂ which is coated with a glass material a lower refractive index 30-2 m. The optical waveguide thus consists of a core 30-1 with the refractive index n ₂ , a cladding (cladding) 30-2 with the refractive index n] and for example a Schutzbe layering (coating / buffer) 30-3 with a refractive index no. The light-guiding core 30-1 serves to guide and transmit the optical signal Si. The cladding 30-2 has a lower optical refractive index than the core 30-1, ie ni <n ₂ . The cladding 30-2 thereby causes a total reflection at the boundary layer to the core 30-1 and thus a guiding of the radiation (ie the optical signal) in the core 30-1 of the optical waveguide 30. The optical filter element 32 along the core 30-1 of Optical waveguide structure 34 is arranged in the fiber core 30-1 in the form of a periodic modulus of refractive index, with high m ₃ ) and low refractive index regions ₍ n ₂ ) reflecting back the light in the fiber core 30-1 of a particular wavelength β, and thus have the function of a band-stop filter, with n ₃ »n ₂ . The center wavelength λβ of the filter bandwidth is given by the Bragg condition λ _Β = 2neff * \. (1 )

Therein, r _{ff is} the effective refractive index of the fiber core 30-1 of the optical waveguide structure 30 and Λ the grating period. The spectral width of the band (blocking band) depends on the length of the fiber Bragg grating 32 and the strength of the refractive index change between the adjacent refractive index regions.

FIG. 2b shows, by way of example, the reflection behavior of the optical waveguide structure 30 with the Bragg filter 32. The spectrum of the input power Pj of the optical input signal Si over the wavelength λ. The Bragg filter 32 acts as a bandpass filter, so that a portion of the injected spectrum is reflected back as a reflected portion PRI, ie the Bragg filter 32 acts as a band-stop filter about the center wavelength λβ. In addition, in FIG. 2b, the transmission spectrum of the transmitted or continuous power Pr _{r is} shown by way of example, in which the component around the center frequency β has been removed from the transmission spectrum by the Bragg filter 32.

With regard to the power spectra shown in FIG. 2b, it should be noted that these are to be regarded as merely exemplary. Thus, it should be noted in particular that the band-stop filter functionality implemented by a Bragg filter permits extremely narrow blocking or reflection ranges around the central wavelength λβ, while in FIG. 2b this blocking region is shown relatively wide for the purpose of simplifying the illustration.

As can be seen from the above equation (1), the center wavelength λβ of the Bragg filter 32 depends on the effective refractive index as well as on the grating period Λ of the optical filter element 32 formed as a fiber Bragg gate. In this context, it is now pointed out that the grating period Λ by an applied mechanical load, ie a strain or compression due to a tensile, compressive, impact, shock or bending load changes. Thus, if the optical waveguide structure 30 with the optical filter element 32 is mechanically coupled to the planar glazing element 20, then strain or compression deformations due to mechanical or even thermal stress of the planar glazing element 20 also affect the Bragg filter 32 the optical waveguide structure 30 transferred at least partially, so the grating period changes Λ of the Bragg filter 32 and thus also the co tenwellenlänge λβ of the Bragg filter 32. Moreover, the refractive indices n _2, n ₃ in the fiber core 30-1 also temperature dependent, so that additionally changes the center wavelength λβ according to the thermal load, which acts on the planar glazing element 20 and thus also on the optical filter element 32 of the optical waveguide structure 30.

It follows that the change in length Δλβ has a dependence on the applied mechanical and thermal load:

As a result, it is achieved according to the invention that a mechanical or thermal stress of the flat filter element 20, for example during a burglary attempt or during heavy use during use, for example as a windscreen of a Vehicle, a change in the optical property of the optical waveguide structure 30 and in particular of the integrated therein Bragg optical filter 32 is caused.

FIG. 2 c now shows by way of example resulting power spectra of an optical waveguide structure 30 which has two optical filter elements (not shown in FIG. 1 a or 2 a). In this case, the two Bragg filters are each formed so that they have different center wavelengths λβ _ΐ , λβ ₂ , so that knowing the position of the first and second optical filter element with a change in the center wavelength βΐ, λβ _{2 in} addition to the size of the mechanical or thermal load can also be closed to a position at which the mechanical or thermal stress of the planar glazing element 20 takes place. Since Bragg filters can now be embodied as extremely narrow bandstop filters with a fixed associated wavelength λβ _η , a larger number of Bragg filters 32-n can also be realized in the optical waveguide structure 30 so that spatially resolved monitoring of the planar glazing - Elements 20 can be realized with respect to mechanical and / or thermal external stresses.

However, all implementations have the same basic principle as that, due to the change in the center wavelength Δλβ _{η of} the Bragg filter, the magnitude of the externally applied mechanical or thermal stress can be assigned, so that when a limit value is exceeded, at least one of the optical filter elements 32 becomes critical (Abnormal) state, eg a burglary attempt, can be found on the surface glazing element 20. Moreover, it is possible to detect simultaneously with the optical waveguide structure 30 integrated in a planar glazing element 20 if a rupture of the glazing element 20 and thus the rupture or kink of the optical waveguide structure 30 occurs, then from an optical filter element 32 in the optical waveguide structure 30 in the light-in direction the break point is arranged, no or a greatly reduced reflection signal returns and thus can be safely concluded that mechanical damage in the form of a fracture of the glazing element 20.

FIG. 3 shows a possible exemplary embodiment of the glazing arrangement 10 according to the invention. In the planar glazing element 20, an optical waveguide structure 30 having a plurality of optical filter elements 32-n is arranged. The optical waveguide structure 30 is now formed again in order to couple the optical signal Sj to the optical waveguide structure 30 at a coupling-in port 30, wherein, for example, a first portion of the optical signal at the first center wavelength β _ΐ is first at the first Bragg filter element 32-1 Reflection signal SRI, at the second Bragg filter 32-2 at a second center wavelength λβ ₂ a second reflection signal SR ₂ USW. up to the last Bragg filter element 32-n at a center wavelength _B, the reflection signal S "is reflected back to the coupling connection 36. Furthermore, it is also possible, on an optional Auskoppelan circuit 38, the transmission spectrum Ρχ _Γ in the form of the passage signal Sx _r to investigate changes in one or more of the center wavelengths of one or more of the Bragg filters 32.

As shown in Fig. 3, the optical waveguide structure 30 with the optical filter elements 32-n is meandered on the sheet glazing element 20 and, for example, within a specially provided recess (not shown in Fig. 3), e.g. positive, non-positive or cohesive, attached to the sheet-like glazing element 20. Thus, arranged as sensor elements Bragg filter 32-n distributed in a grid on the flat glazing element 20 are arranged. In this case, the distances A, B or C between adjacent Bragg filters 32-n can be chosen such that, depending on the thermal conductivity or the thermal diffusivity of the planar glazing element 20, i. of the material surrounding the individual Bragg filters 32-n, with a point heating of the disk by e.g. 500 ° C (or more) at the nearest Bragg filter within a period of e.g. <5 seconds, a temperature increase, e.g. greater than 10 ° C, is caused. Its center wavelength would typically increase by at least about 100 pm.

By way of example, the optical waveguide structure 30 with the optical filter elements 32-n can be arranged on the planar glazing element 20 such that at least one Bragg filter 32 is arranged per unit area (for example 0.01-1.0 m ² ) in order to reliably detect a thermal or To detect mechanical stress on a change in the optical properties of the optical waveguide structure (cn).

As shown in FIG. 3, the plurality of optical filter elements 32-n are arranged along an optical waveguide structure 30. According to the invention, it is equally possible to use a plurality of optical waveguide structures 30-1, 30-n each with one or more optical filter elements, e.g. in the form of a Bragg filter, to provide in the planar glazing element 20 to attach a plurality of optically separate sensor circuits to the planar glazing element 20. This can be advantageous in the case of a very large glazing element 20.

The optical waveguide structure 30 shown in FIG. 3 can also be arranged on the planar glazing element 20 within a depression or recess in the planar glazing element 20. For example, by means of a compound-producing adhesive (not shown in FIG. 3), the element 20 may be arranged mechanically on the planar glazing element 20 in order to produce sufficient mechanical and thermal coupling between the glazing element 20 and the optical waveguide structure 30, as already described. Hand of Fig. La-b has been explained, the local versions is equally applicable to the arrangement shown in Fig. 3.

The glazing arrangement 10 with safety function shown in FIG. 3 is on the one hand suitable for detecting mechanical deformations due to a thermal or mechanical action on the planar glazing element 20. In addition, with the glazing arrangement shown in Fig. 3a also a fraction of the planar glazing ungselements 20 and thus due to a corresponding break or break also the optical waveguide structure 30 are detected. FIG. 3 shows, by way of example, a break point 60 within or on the planar glazing element 20. The reflected signal SR "obtained at the terminal 36 now contains no or greatly reduced reflection signals of the Bragg filters 32-9, 32-10 ... 32-n shown in FIG. 3, which are arranged in the light coupling device after the break point 60. Thus, a mechanical breaking of the glazing element 20 and thus a breaking or buckling of the optical waveguide structure 30 can be detected and assigned to a position between the two Bragg filter elements 32-8 and 32-9. Thus, with the reflection signal SR and depending on the respective spacing of the Bragg filter elements 32-n, a local resolution of a thermal or mechanical stress of the planar glazing element 20 via a change of individual Mittenwel 1 lengths λβ _η , or a localization of a fraction of the areal Vergl tion element, by detecting a failure of the reflection signals or a sharp decrease (> 50%) of the amplitude of the reflection signal SR "of the Bragg filter elements after a break point.

With regard to a spatial resolution or spatial assignment of a mechanical stress on the glazing element 20, it is pointed out that this mechanical stress can only be detected in a spatially resolved manner with the use of a plurality of Bragg filter elements at the areas of the glazing element where there is a fixed mechanical connection of the optical waveguide structure 30 is present with the optical filter elements 32 on the glazing element. If, for example, the optical waveguide structure 30 is mechanically connected to the glazing element 20 over the entire length, a spatial resolution of a mechanical stress acting on the glazing element 20 can be achieved over the entire length of the optical waveguide structure 30 on which Bragg filter elements are arranged. The local resolution corresponds to the spacing of the filter elements. However, if, for example, the optical waveguide structure 30 is subsequently introduced into a capillary 40 provided on the glazing element 20, it is often only possible to mechanically fix it between the optical waveguide structure at the respective end pieces of the optical waveguide structure 30 which project from the glazing element 20 30 and the glazing element 20 make. With a mechanical stress of the glazing element 20, only one elongation caused relatively evenly over the entire optical waveguide structure 30 arranged in the glazing element 20 can be detected, so that it is only recognized that a mechanical stress occurred somewhere along this capillary (and not in adjacent ones) ,

With regard to the above discussion of possible alternatives for a mechanical arrangement of the optical waveguide structure 30 on the glazing element 20, it should be clear that with only a partial, fixed mechanical connection of the optical waveguide structure 30 to the glazing element 20 within the fixed mechanical connection regions, a mechanical stress on the glazing element is transferred to the optical waveguide structure 30, while on any intermediate area without such a fixed mechanical connection, a mechanical stress of the glazing element 20 is transmitted as a relatively uniform strain between the mechanical connection points, a precise spatial resolution is therefore not possible.

In this context, it should be noted that a local resolution at a thermal stress of the glazing element 20 i. W. is independent of the mechanical connection between the optical waveguide structure 30 and the glazing element 20, as long as a sufficiently good thermal coupling of the optical waveguide structure 30 with the glazing element 20 over the entire length of the optical waveguide structure 30 is present, which is already given by resting. In the following, an exemplary embodiment for a security system 70 for glazing will now be described by way of example with reference to FIG. 4.

As shown in FIG. 4, the security system 70 has, for example, a glazing arrangement 10, as described with reference to the preceding FIGS. 1a-b, 2a-c and 3, which can be used in the exemplary embodiment shown below.

As further illustrated in FIG. 4, a signal input device 80 for coupling an optical signal i into the optical waveguide structure 30 is connected to the coupling 1 intended. Further, a signal detecting means 82 for detecting an optical signal (ie, the reflection signal SR and / or optionally the Transmi ssionssi signal sx _r ) of the optical waveguide structure 30 and for outputting an electrical detection signal S _e based on the detected optical signal SR and Sj _{T is} provided , The signal injection device 80 is thus designed as an optical transmitter, while the signal detection device 82 is designed as an optical receiver. The signal detection device 82 is designed such that it can detect, for example, the reflection signal SR provided at the coupling connection 36 and optionally the optional transmission signal Sj provided at the optional coupling connection 38 or the respective power spectrum. In the signal detection device, the detected optical signals are converted, for example, into electrical signals S _e for further processing and / or evaluation by a processing device 90. The processing device 90 is provided on the one hand to control, for example, the signal input device 80 for coupling in the optical signal Sj and also to evaluate the detection signal S "provided by the signal detection device 82 based on the reflection signal SR or the transmission signal 8χ _Γ . In this case, the processing device 90 is in particular designed to detect a change in the property of the Lichtwel lenleiterstruktur 30 at a mechanical or thermal stress of the glazing element 20. The processing device and optionally also the signal input and signal detection device 80, 82 may be arranged adjacent to the glazing arrangement 10 or via an optical waveguide connection (not shown in FIG. 4) remote from the glazing arrangement 10, for example to prevent unauthorized access and manipulation attempts. eg in the event of a break-in, on the security system 70.

As already mentioned above, the processing means 90 may be based on the respective one of the Bragg filters 32-n reflected signal SR or on the transmission signal Sx _r a mechanical or thermal stress of the sheet glazing element 20, and thus the mechanically coupled lightwave waveguide structure Determine 30 with the Bragg filter element 32 and the plurality of Bragg filter elements 32-n. Thus, the processing device 90 can detect a change in the center wavelength λβη of at least one of the Bragg filter elements 32-n and output when exceeding a comparison value for a wavelength change, a corresponding display signal or alarm signal SQUT at a Ausgangsansehl uss 92.

Furthermore, the processing device 90 can output a corresponding alarm output signal SQUT at the output terminal 92, if the reflection signals of all the Bragg filter elements 32-n are not contained in the reflection signal SR, since this is due to a break of the planar glazing element 20 and thus indicates a break or kink of the optical waveguide structure 30.

The processing device 90 is designed to compare the detection signal S _e or a signal derived therefrom with a comparison value in order to determine whether the detection signal is within or outside a desired range, and to exceed the limit value for to indicate a mechanical or thermal load of the planar glazing element 20. The comparison value may be determined, for example, based on an average or a plurality of preceding measurement values of the detection signal or signals derived therefrom. It can thus be achieved that, for example, a relatively slow thermal temperature change on the planar glazing element, as occurs, for example, due to solar radiation, does not lead to the triggering of an alarm, while, for example, a heat effect of high power, as is caused, for example, by a gas burner of a burglar, extremely fast or immediately leads to an alarm signal. Today's gas burners have a heat radiation of more than 1900 ° C and a power of over 50 kW. In addition to a relative comparison value, which is readjusted based on an average value or a quantity derived therefrom of a plurality of preceding measured values of the detection signal, a second fixed comparison value can be provided, beyond which an alarm is triggered in any case, since this is in any case attributable to an high thermal or mechanical stress of the planar glazing element 20 hin- points, even if it has risen only slowly.

As described above, the detection signal or the signal derived therefrom is based on a center frequency of the respective Bragg filter or a level of the detected signal. The processing device 90 is thus designed to detect the spectral distribution of the signal components in the reflection signal S and also the respective level and to investigate a change in the respective signal components due to mechanical or thermal stress.

In the glazing security system 70 shown in FIG. 4, the signal coupling device 80, the signal detection circuit 82 and the processing device 90 are shown in the schematic representation as separate elements or components, but these elements or components also become a single element Assembly 100 can be summarized. The assembly 100 is also referred to as an optical sensor interrogator or fiber Bragg grating optical interrogator. In addition, it should be noted that available fiber bragg grating interrogators may for example monitor up to 100 Bragg filter elements in series, so that with only a single interrogator a relatively high spatial resolution can be achieved by monitoring a large number of Bragg filter elements in the Optical waveguide structure 30 can be achieved. Furthermore, the number of measuring points can be increased by using an optical switch (not shown in FIG. 4).

In principle, extremely small strains or compressions can be detected by a Bragg grating, as they are already caused by slight contact with the disk or, in the case of larger disks, by the wind pressure. Furthermore, comparable shifts in the center wavelength of a Bragg grating but also caused by temperature fluctuations by a few ° C. The security system 70 according to the invention can now be adapted to suit specific applications, e.g. depending on the lens design, to set at which wavelength shift an alarm is triggered. A distinction between punctual thermal and mechanical loads, for example, possible in that when bending a disc several adjacent Bragg grating respond simultaneously, while the heat propagation is relatively slow, so that adjacent Bragg grating only at a distance of a few seconds to minutes respond, depending after distance and disc structure.

In addition, it is pointed out that it is possible with the glazing arrangement according to the invention with the safety function or the safety system according to the invention to carry out an analysis of a mechanical action on the glazing arrangement in order, for example, to distinguish between the action of one or more (intended ) Impacts that are expected to damage the glazing assembly and incidental events that affect the glazing assembly, such as a supersonic blast of an airplane, an incidental incident football, etc., to hit. In this case, the occurrence of several blows in a certain period, e.g. a break-in attempt with respect to the glazing assembly, while a single strike indicates a random event in the environment over a longer period of time.

Since the Lichtwel lenleiterstruktur having a plurality of Bragg filters, with the processing means 90 of the security system 70 also an evaluation of the sensor results in the form of pattern recognition can be performed. In doing so, a musical the changes in the optical properties of the optical waveguide structure in the form of the respective average wavelengths λβ of the affected Bragg filters are made by the amplitudes of the changes of the means wavelengths Δλβ the respective mechanical action (s) and also the temporal occurrence of the changes of Average wavelengths Δλβ are analyzed.

For a mechanical load, e.g. In the form of a violent impact or impact load, a locally applied to the V erg lasungsanordnung, a mechanical deformation in the glass material of the glazing assembly, starting from the Einwir- kungspunkt (eg wave-like) spread, so that a pattern recognition or impact pattern recognition with respect to the acting mechanical Load can be made. Thus, starting from the impact point on the glazing, a distance and time decreasing pattern of changes Δλβ of the optical properties of the optical waveguide structure, i. their amplitude and temporal occurrence, resulting from the respective center wavelengths β of the Bragg filter concerned.

If, for example, a strong mechanical load occurs in the form of a so-called supersonic bang of an aircraft (ie the mechanical load is based on a strong acoustic source in the near or far environment), this mechanical load will be distributed relatively uniformly over the surface of the glazing arrangement that a uniformly distributed pattern of change (s) Δλβ of the optical properties of the optical waveguide structure, ie their amplitude and timing, from the respective center wavelengths λβ of the affected Bragg filters, i. essentially all Bragg filters will result.

Thus, a clear distinction between very locally occurring mechanical stresses, which can be repeated, for example in the form of multiple acting shocks, and random individual events, which act on the glazing arrangement, possible. The optical waveguide structure with the Bragg filters is used, for example, up to microseconds, e.g. with a clock of at least 1ms, 0.1ms or ΙΟμβ (eg 1ms to 50μβ) and a readout frequency of at least 1kHz, 10kHz or 100kHz (eg 1 to 20kHz) to obtain a sufficient resolution of the resulting pattern in a to obtain mechanical action on the glazing structure.

The signal detection device 82 can thus be designed to provide a detection signal S _e based on the changes Δλβ of the optical properties of the same Bragg filters of the optical waveguide structure, which is determined in the case of a mechanical application. Spruchung of the planar glazing element 20 has an information about the mechanical stress at the respective location of the affected Bragg filter, and further having a thermal stress on the planar glazing element 20 information about the thermal stress at the respective location of the affected Bragg filter. The detected change Δλβ of the optical properties of each of the Bragg filters can therefore be used to distinguish both a mechanical and a thermal stress. The processing device 90 can now be embodied to evaluate the detection signal S _{e in} order to determine a local distribution of the mechanical stress over the planar glazing element when the planar glazing element 20 is subject to mechanical stress, and also when the planar glazing element 20 is subject to thermal stress to determine a local distribution of the thermal stress on the planar glazing element 20. The local distribution of the mechanical and thermal stress is based on the local distribution of the plurality of Bragg filters on the planar glazing element 20.

With a sufficiently high readout frequency of e.g. more than 1 kHz, it is possible to distinguish between the above-described mechanical stress, e.g. in the form of a violent impact or shock load relatively locally on the glazing arrangement, and a strong mechanical stress, which relatively uniformly distributed over a larger area of the surface or the entire area of the surface of the glazing arrangement to meet, although corresponding mechanical loads or their effects in the form of vibrations, etc. of the glazing arrangement relatively quickly, eg in the range of 1 s to 10 ms, can decay.

In addition, it is achieved that sufficient information is provided by means of the optical decoupling signal of the optical waveguide structure 30 to make a distinction as to the occurrence of any short-term mechanical stress whose effects dissipate relatively rapidly and thermal stress due to thermal stress relatively slow heat propagation through the glazing arrangement with a greater time delay adjacent Bragg grating only at a distance of a few seconds to minutes reached, depending on the distance of the respective Bragg grating and the specific disk structure. Thus, it can be stated that the occurrence of different mechanical stresses as well as thermal stresses on the glazing arrangement or their respective local distribution can be resolved very precisely in accordance with the distribution of the plurality of Bragg filters on the planar glazing element, if the layout Sequenz sufficiently high. Thus, the changes Δλβ of the optical properties of each Bragg filter can be used to detect both the occurrence of mechanical stresses (or different mechanical stresses) and thermal stresses (or different thermal stresses) of the glazing assembly and their respective local distribution.

In addition, it is pointed out that, for example, in the case of a laminated glass arrangement for the glazing element within the composite arrangement, a thermally conductive foil, i. H. a film with a heat-conducting property increased in relation to the surrounding glass material can be used to distribute the applied thermal stress as quickly as possible over the glazing element when exposed to a point, thermal heat source, in order to heat the glass material in the vicinity in near real time a Bragg filter element in the optical waveguide structure 30 to immediately (within a few seconds) to detect an indicative of a Manu- pulation heat action.

An embodiment of a basic method 100 for detecting a mechanical or thermal stress of a planar glazing element will now be described below with reference to FIG. 5, wherein an optical waveguide structure with an optical filter element is arranged on the planar glazing element. In the method 100, an optical signal is first coupled into the optical waveguide structure in a first step 102. Furthermore, an optical signal, for example in the form of a reflection signal or a transmission signal, of the optical waveguide structure is detected and converted into an electrical detection signal based on the detected optical signal of the optical waveguide structure (step 104). This electrical detection signal or a signal derived therefrom is evaluated (step 106) in order to determine a change in the optical property of the optical waveguide structure due to a mechanical or thermal stress of the planar glazing element. As an optional step 108, the electrical detection signal or the signal derived therefrom may be compared to a comparison value to determine if the detection signal is outside a desired range, indicating an exceeding of a mechanical or thermal stress limit on the sheet glazing element , In this case, the comparison value can be predefined or can be determined as a relative comparison value based on a statistical processing of a plurality of preceding measured values of the electrical detection signal. Aspects of the inventive concept for a glazing arrangement with security function or a security system for a glazing arrangement are summarized below. In a burglary attempt, for example, the safety glass of a jeweler's display or other display protecting disc by means of a gas burner under heat or heat to be changed in stability so as to melt the safety glass at least partially so that access to the behind the safety glass lying area to be protected for an unauthorized person (eg a burglar) is made possible. A burglar has thus relatively quickly access to the issued behind the safety glass valuables, as previous fracture sensors or vibration sensors often do not respond to the use of a gas burner and thus no alarm is triggered. For this reason, in order to identify a heat source in the security area, expensive thermal imagers had to be used to obtain timely information.

The concept according to the invention consists in providing a glazing arrangement (safety glass) with a reliably functioning safety function by providing on the flat glazing element an optical waveguide structure with one or more optical filter elements, such as e.g. one or more Bragg filters, the optical waveguide structure within a recess or depression in a multilayer safety glass, e.g. in a capillary or a milled groove, or subsequently applied to the safety glass in capillaries. Since the center wavelength λβ of a Bragg filter depends both on a mechanical elongation and on a heat effect, mechanical or thermal stresses of the planar glazing element caused by third parties can now very quickly or rapidly due to a transfer of the exerted mechanical or thermal stress on the optical filter element in near real time, eg within a few seconds, as an attempted manipulation, such as a burglary in which the flat glazing element is detected and an electronic alarm is triggered in order to disturb the unauthorized person or to alert a security service or the police.

In addition, a plurality of Bragg filters within the optical waveguide structure, which each have a different central wavelength λ _Β , can be optically switched in series, so that the Lichtwel lenleiterstruklur beyond also simultaneously usable as a breakage sensor. According to the invention, this is possible since, in the direction of the coupled-in signal after the respective breakage point of the planar glazing element and thus of the optical waveguide structure, no reflection from the following Bragg filters is possible. returned signals to the detection device. Thus, depending on the selected local distribution of the Bragg filter, an (at least rough) localization of the break point on the planar glazing element can be effected. A typical optical waveguide structure with an optical filter element embodied as a Bragg filter has, for example, a diameter of 80-200 μm, so that it can be attached to the flat glazing element, for example, in small capillaries or milled grooves with a diameter of 200-650 μm. Typical distances of adjacent rows of optical waveguides or of adjacent optical filter elements can be, for example, in the range of 10-100 or 10-40 cm. If, for example, the planar glazing element has a laminated glass, the optical waveguide structure can be located in a capillary behind the first pane (with respect to the outside of the planar glazing element). As already mentioned above, it is possible to connect a plurality of Bragg filters in succession in order to ensure a better dissolution of a breakage point or of a location of the action of a mechanical or thermal stress on the planar glazing element. In this case, the required maximum distance to the arrangement of the optical filter elements of the optical waveguide structure can be individually made dependent on the respective planar glazing element, ie its thermal conductivity or thermal diffusivity, and adjusted.

The inventive concept for a glazing arrangement with safety function can also be subsequently integrated into an existing safety glass, wherein in a subsequent installation in recesses or recesses to be provided (eg capillary or groove), the optical waveguide structure (s) to be selected by means of a film in an individually according to the respective safety glass Distance to be glued to the flat glazing element. As already stated above, precise values for the exact positioning of the optical waveguide structure with the optical filter elements can be based on the thermal conductivity or the thermal conductivity of the respective safety glass or laminated glass.

By means of designed as a break, strain and heat sensor optical waveguide structure can now very effectively (relatively) large amounts of heat, eg a gas burner, delektieren very fast and almost in real time. Today's gas burners have a heat radiation of more than 1900 ° Celsius and an output of more than 50 kW. In addition to the amount of heat supplied and the resulting change in the respective center wavelengths λβ of the affected Bragg filters, it is also possible simultaneously to measure mechanical effects, for example in the form of an elongation or a fracture. erroneous measurements or disturbances of the measurements, as they are caused for example by the sunlight, can be excluded, for example, that individual optical filter elements are evaluated as a reference filter or adjacent Bragg filter to prevent any incorrect assessment of a measurement result. Thus, for example, a comparison value with which the respective measured value of the reflective optical signal or a variable derived therefrom is compared can be provided with a correction factor which is determined, for example, on an average value or a quantity derived therefrom of a plurality of preceding measured values of the detection signal. Accordingly, the comparison value can also be determined based on or from an average value of all detected reflection components in the reflection signal.

It should be noted that, in the case of a thermal load on the glazing arrangement, the optical property of the optical waveguide structure in the form of the respective center wavelengths .lambda..sub.β of the relevant Bragg filter will change continuously or continuously (at least in regions or up to damage of the optical waveguide structure) this change can be evaluated accordingly and assigned to a thermal load. By contrast, in the case of a mechanical load (in the form of a severe shock or impact load and a corresponding damage) of the glazing arrangement, the optical property of the optical waveguide structure in the form of the respective center wavelengths β of the affected Bragg filters becomes relatively abrupt if the optical waveguide structure is damaged or change abruptly, and this change is evaluated accordingly and a mechanical load can be assigned.

The glazing arrangement with safety function according to the invention is not only applicable for the prevention or detection of burglary, but also in safety-relevant applications in which planar glazing elements are exposed, for example, strong thermal or mechanical loads and also determines any increased mechanical or thermal load conditions as quickly as possible or almost in real time should be. Thus, for example, the glazing arrangement according to the invention having a safety function can be used on the windshield of a towing cockpit or of another vehicle or rail vehicle and monitored in accordance with the procedure according to the invention. In this context, it should be noted that an optical waveguide structure with an optical filter element, which is designed as a break, strain or thermal sensor, is substantially insensitive to electrical or electromagnetic interference signals and thus extremely reliable and insensitive to interference can perform the respective monitoring function. The glazing arrangement according to the invention with a safety function thus enables the Li cht wel Icnlci terstruktur formed as strain, breakage and thermal sensor directly provides the required information regarding the mechanical or thermal stress of the surface glazing element to be monitored, and thus no different sensor types for detecting heat , Stretching and breakage are needed. In this context, it should be noted that so far for the identification of a heat source in the security area i. A. elaborate thermal imaging cameras were used, a timely information should be obtained. The erfmdungsgemäße concept for a safety glass is therefore everywhere applicable where valuables or other goods to be protected against unauthorized access or access, such as banks, jewelers, department stores, etc. In addition to this burglary prevention or security aspect, the inventive concept equally flat Glazing elements are used, which are subject to use relatively strong, mechanical or thermal stresses are exposed to an excessive mechanical or thermal stress of the respective planar glazing element as early as possible or almost in real time.

Although some aspects have been described in the context of a device, it will be understood that these aspects also constitute a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device. Some or all of the method steps may be performed by a hardware device (or using a hardware device). Device), such as a microprocessor, a programmable computer or an electronic circuit. In some embodiments, some or more of the most important method steps may be performed by such an apparatus (sensor interrogator).

Depending on particular implementation requirements, embodiments of the invention may be implemented in hardware or in software. The implementation may be performed using a digital storage medium, such as a floppy disk, a DVD, a Blu-ray Disc, a CD, a ROM, a PROM, an EPROM, an EEPROM or FLASH memory, a hard disk, or other magnetic disk or optical memory storing electronically readable control signals that interact with a programmable computer system. or that the respective procedure is carried out. Therefore, the digital storage medium can be computer readable. Thus, some embodiments according to the invention include a data carrier having electronically readable control signals capable of interacting with a programmable computer system such that one of the methods described herein is performed.

In general, embodiments of the present invention may be implemented as a computer program product having a program code, wherein the program code is operable to perform one of the methods when the computer program product runs on a computer. The program code can also be stored, for example, on a machine-readable carrier. Other embodiments include the computer program for performing any of the methods described herein, wherein the computer program is stored on a machine-readable medium. In other words, an exemplary embodiment of the method according to the invention is thus a computer program which has a program code for carrying out one of the methods described here when the computer program runs on a computer. A further embodiment of the inventive method is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program is recorded for carrying out one of the methods described herein. Another embodiment includes a processing device, such as a computer or a programmable logic device, that is configured or adapted to perform one of the methods described herein.

Another embodiment includes a computer on which the computer program is installed to perform one of the methods described herein.

In some embodiments, a programmable logic device (eg, a field programmable gate array, an FPGA) may be used to perform some or all of the functionality of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor to perform one of the methods described herein. In general, in some embodiments, the methods are performed by any hardware device. This can be a universally applicable Hardware such as a computer processor (CPU) or hardware specific to the process, such as an ASIC.

The above described embodiments are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims, rather than by the specific details presented in the description and explanation of the embodiments herein.

Claims

claims

Security system (70) for glazing, comprising: a glazing assembly (10) having a security function with a sheet-like glazing element (20); and an optical waveguide structure (30) having an optical filter element (32); wherein the optical waveguide structure (30) is mechanically arranged on the glazing element (20) to cause a change in an optical property of the Lichtwel lenlei terstruktur (30) at a mechanical stress of the planar glazing element (20), and further at a thermal stress of the planar glazing element (20) to cause a change in an optical property of the Lichtwel lenleiterstruktur (30); a signal input device (80) for coupling an optical signal (S into the optical waveguide structure (30); a signal detection device (82) for detecting an optical signal (SR _; SI) of the optical waveguide structure (30) and outputting an electrical detection signal (S _e ) on the detected optical signal (SR, S- _lr ); and processing means (90) for driving the signal injection means (80) and for evaluating the detection signal provided by the signal detection means (82), the processing means (90) being adapted to provide a Change in the optical property of the optical waveguide structure (30, 32) due to a mechanical stress of the planar glazing element (20) to determine, and further to a change in the optical property of the light wel lel ei terstruktur (30, 32) due to thermal stress of the planar To determine glazing element (20).

The security system of claim 1, wherein the optical filter element (32) comprises a Bragg filter or a plurality of Bragg filters.

A security system according to claim 1 or 2, wherein the optical waveguide structure (30) comprises a plurality of serially arranged, spaced apart optical filter elements (32) in the form of Bragg filters, the Bragg filters each having a different filter center wavelength.

4. Security system according to claim 3, wherein the optical waveguide structure (30) is arranged so that the Bragg filters (32) are arranged in a distributed arrangement or in a grid on the planar glazing element (20).

5. Security system according to one of the preceding claims, wherein the optical waveguide structure is positively, positively or materially connected to the planar glazing element (20).

6. Security system according to one of the preceding claims, wherein the optical waveguide structure (30) with the optical filter elements (32) is integrated in the material of the glazing element.

7. Security system according to one of the preceding claims, wherein the change in the optical property of the optical waveguide structure based on a force and / or temperature-dependent material strain or on a temperature-dependent refractive index change of the material of the formed as a Bragg filter optical filter element.

8. Security system according to one of the preceding claims, further comprising the following features: a further optical waveguide structure (30 ') with at least one further optical filter element (32') in the form of a Bragg filter.

9. The security system of claim 8, wherein the further optical waveguide structure (30 ') comprises a plurality of serially arranged, spaced apart optical, further filter elements (32') in the form of Bragg filters, wherein the Bragg filters each have a different filter center wavelength.

10. Security system according to one of claims 8 or 9, wherein the processing device (90) is designed to evaluate the detection signal (S _e ) or a signal derived therefrom, based on a affected by a mechanical and / or thermal stress filter element ( 32 ') to determine a spatial allocation of the acting mechanical or thermal load on the glazing element.

A security system according to any one of the preceding claims, wherein the processing means (90) is arranged to compare the detection signal (S _e ) or a signal derived therefrom with a comparison value to determine whether the detection signal (S _e ) is within or outside of a desired range, wherein leaving the target range indicates that a limit for a mechanical or thermal load of the planar glazing element (10) is exceeded.

12. Security system according to one of the preceding claims, wherein the processing device (90) is designed to evaluate the detection signal (S _E ) to determine whether the optical property of the optical waveguide structure in the form of the respective center wavelengths% Q of the affected Bragg filter continuously or continuously changes to determine a thermal load, and wherein the processing means (90) is further configured to evaluate the detection signal (S _E ) to determine whether the optical property of the optical waveguide structure in the form of the respective center wavelengths λ "of the affected Bragg filter abruptly or changes abruptly to determine a mechanical load.

13. The security system of claim 1, wherein the comparison value is based on an average or a derived quantity of a plurality of preceding measured values of the detection signal of a Bragg filter or a plurality of Bragg filters.

A security system according to any one of the preceding claims, wherein the detection signal (S _E ) or the signal derived therefrom is based on a center wavelength (λβ) of the respective Bragg filter or on a power level of the detected signal.

15. Security system according to one of the preceding claims, wherein the processing device (90) is adapted to output a warning or alarm signal (S _out ), if exceeding a limit value for a mechanical or thermal load of the planar glazing element (20) occurs.

16. Security system according to one of the preceding claims, wherein the signal detection means (82) is adapted to read out the optical signal (SR, Sr _r ) of the optical waveguide structure (30) with a read-out frequency of at least 1 kHz.

17. Security system according to one of the preceding claims, wherein the processing device (90) is designed to evaluate the detection signal to determine a mechanical distribution of the planar glazing element (20) a local distribution of the mechanical stress on the flat glazing element , And further to determine at a thermal stress of the planar glazing element (20), a local distribution of the thermal stress on the flat glazing element (20).

18. glazing assembly (10) with safety function, comprising: a flat glazing element (20); and a light guide structure (30) having an optical filter element (32); wherein the optical waveguide structure (30) is mechanically arranged on the glazing element (20) to cause a change in an optical property of the optical waveguide structure (30) under mechanical stress of the planar glazing element (20) and further under thermal stress of the planar glazing element (20) to cause a change in an optical property of the optical waveguide structure (30).

The glazing assembly of claim 18, wherein the optical filter element (32) comprises a Bragg filter or a plurality of Bragg filters.

The glazing assembly of claim 18 or 19, wherein the light guide structure (30) comprises a plurality of serially arranged spaced apart optical filter elements (32) in the form of Bragg filters, the Bragg filters each having a different filter center wavelength.

The glazing assembly of claim 20, wherein the light guide structure (30) is arranged such that the Bragg filters (32) are arranged in a distributed arrangement or in a grid on the planar glazing element (20).

22. Glazing arrangement according to one of claims 18 to 21, wherein the Lichtwelienleiterstruktur is positively, positively or cohesively connected to the flat Verglasungseiement (20).

23. Glazing arrangement according to one of claims 18 to 22, wherein the optical waveguide structure (30) with the optical filter elements (32) is integrated in the material of the Vergiesungselements.

24. Glazing arrangement according to one of claims 18 to 23, wherein the change in the optical property of the optical waveguide structure based on a force and / or temperature-dependent material strain or on a temperature-dependent refractive index change of the material of the formed as a Bragg filter optical filter element.

25. Glazing arrangement according to one of claims 18 to 24, further comprising the following features: a further optical waveguide structure (30 ') with at least one further optical filter element (32') in the form of a Bragg filter.

26. A glazing assembly according to claim 25, wherein the further optical waveguide structure (30 ') comprises a plurality of serially arranged, spaced apart optical, further filter elements (32') in the form of Bragg filters, wherein the Bragg filters each have a different filter center wavelength.

27. A method for detecting a mechanical or thermal stress of a planar Vergiesungselements (20), wherein on the planar glazing element (20) an optical waveguide structure (30) with an optical filter element (32) is mechanically arranged, comprising the following steps:

Injecting (102) an optical signal into the optical waveguide structure;

Detecting (104) an optical signal of the optical waveguide structure and generating an electrical detection signal based on the detected optical signal of the optical waveguide structure;

Evaluating (106) the electrical detection signal or a signal derived therefrom to determine a change in the optical property of the optical waveguide structure due to mechanical stress of the planar Vergiesungselements, and further to determine a change in the optical property of the optical waveguide structure due to thermal stress of the planar Vergiesungselements ,

28. The method of claim 27, further comprising the step of:

Comparing (108) the electrical detection signal or the signal derived therefrom with a comparison value to determine whether the detection signal is outside a desired range, indicating an exceeding of a limit value for mechanical or thermal loading of the planar Vergla- sungselements.

29. The method of claim 27 or 28, further comprising the steps of:

Evaluating the electrical detection signal (S _e ) to determine whether the optical property of the optical waveguide structure in the form of the respective center wavelengths λβ of the affected Bragg filter changes continuously or continuously to determine a thermal load, and

Evaluating the electrical detection signal (S _e ) as to whether the optical property of the optical waveguide structure in the form of the respective center wavelengths λβ of the affected Bragg filter changes abruptly or abruptly to determine a mechanical load.

30. The method of claim 28 or 29, wherein the comparison value is fixed or is determined based on a statistical preparation of a plurality of preceding measured values of the electrical detection signal of one or a plurality of Bragg filters.

31. The method according to any one of claims 27 to 30, further comprising the following steps:

Evaluating the detection signal (S _e ) or a signal derived therefrom in order to determine, based on a filter element (32 ') affected by an acting mechanical and / or thermal stress, a spatial assignment of the acting mechanical or thermal load on the glazing element.

32. Computer program with a program code for carrying out the method according to any one of claims 27 to 31, when the program runs on a computer or a microprocessor.