ES2268822T3 - ELECTROLUMINISCENT SOLID SEMICONDUCTOR ELEMENT AS A MEANS OF CHECKING FOR LUMINISCENT SAFETY CHARACTERISTICS. - Google Patents

Abstract

The arrangement has ultraviolet and/or infrared electro-luminescent semiconducting solid state elements e.g. light emitting diodes (2,3) and, optionally, a light element (4) whose radiation lies in the visible band. The elements are mounted together in a housing (5) to produce a focused light beam containing both visible and non-visible components. A spring-loaded push button is operated to activate the combination of elements. An Independent claim is also included for a method of monitoring luminescent security characteristics.

Description

Solid semiconductor element electroluminescent as a means of checking for characteristics luminescent safety.

The present invention relates to a method and to a device according to claims 1 and 7, for the verification of luminescent safety features based on diodes (LEDs) emitting UV and IR light.

The luminescent safety features for the securities and security sector they are already applied from long time ago To make reliably visible at a cost acceptable, safety features placed on objects of security and value affected, multiple have already been made efforts to develop procedures and devices corresponding.

For the development of procedures and appropriate devices, in most cases, has been proposed Aiming at checking banknotes, credit cards and checks at points of sale. As sales spaces or points of sale have been considered every imaginable type of places where valuable documents are distributed, traded, changed or checked and security, for example, banknotes, credit cards and checks, as well as identification documents and the like. To make available to the circle of corresponding people reliable verifications of the authenticity of valuable documents and security affected, the efforts cited have been made to get procedures and devices for visualization of said luminescent safety elements.

The current state of the art for this is shows in document DE 94 03 794 U with the title "Wertpapier - Prügerät "(Value paper tester). In it, A tester is structured by means of discharge lamps value papers in a correspondingly large, suitable box to house the discharge lamp, a UV light source, and a white light source Consequently, the UV light source makes a large size of the box is necessary, thereby losing it manageability While using a discharge lamp specially developed for this purpose, 60 mm long and 9 mm in diameter, a test device has already been created for keep it handy at all times, easy to handle, it's still something bulky. In addition, due to the preheating of the tube, the operation of the discharge lamp requires a time of minimum performance

WO 93/07590 A describes a U-shaped and banknote checking device quite complicated structure. Sample, for example, during check the roller ticket for pulling a ticket to through the banknote checker. This results in a great expenditure. both regarding development and manufacturing and use of the banknote checking equipment. Further, This verification procedure requires a large expenditure of time these days is not adequate.

US 4,567,370 A shows a Authentication device for samples. For this purpose it is used for checking samples a UV steam lamp mercury. Also in this case, in addition to its large dimensions, during the use of the equipment the time of excessively long operation.

EP 537 513 A1 shows a device for checking banknotes. In the same an excitation on LEDs or IR LEDs occurs Security elements. An area is not mentioned in this publication UV check, so that this spectral zone of the elements Security is left free. A record of the responses to Banknotes are done using a CCD camera, which transmits the signals captured for evaluation. Also in this case they are valid disadvantages of high development costs and manufacturing, relatively large dimensions and great loss of time in checking banknotes.

For this, the current state of the art also shows document DE 296 07 075 U1 and document DE 197 01 513 A1. Document DE 296 07 075 U1 shows a detector of luminescence. The luminescence detector is intended for emit light signals in the UV zone and detect in a zone of checking an object signals reflected in the spectral zone of Visible wavelength and evaluate them using a unit of evaluation planned for this purpose. To do this, the detector of luminescence is equipped with a semi-transparent mirror through the that pass the reflected signals to the detection unit and evaluation. The ray path from the semi-transparent mirror the object to be checked and the ray path of the reflections They are placed on an axis. For targeting it is arranged in this ray path a lens.

Between the semi-transparent mirror and the unit reception are ready for the preparation of reflected signals an additional series of lenses and filters, to enable a spectral location

Thus, the device is quite expensive and the proper procedure for the detection and evaluation of The reflections of the object to be checked is very complex. In consequently they have the disadvantage that, in addition to the unit of emission, a lightning deflection unit in the form is required of a semi-transparent mirror and a reception unit and evaluation. This means a huge cost, both technical and economic. In addition, due to the high technicality there is correspondingly also a sensitivity of the equipment, to have in bill.

Document DE 197 01 513 A1 results in a procedure and a device for checking the authenticity. The procedure uses two emitting sources for the emission of rays on a specific target. Both sources are juxtaposed and, thus, are placed at an angle of irradiation determined with respect to the object, from which the reflections These reflections are recorded and evaluated by a detector. Both sources of lightning work through a unit of check in a division multiplexing procedure of weather. The procedure and the device also provide the record of the reflections and, consequently, are very expensive for his, her nature. Also in this case the argument that, both technically and financially, they must be carried out Great efforts to realize these technical principles.

The procedures and devices present and hitherto known for displaying features of luminescent safety have not yet matured enough to that allow a simple and uncomplicated manipulation with a Reliable recognition of security features.

Therefore, the present invention has the objective of making available a procedure and a device for the verification of luminescent safety features arranged inside and / or on documents or valuables and security, due to the verification of the characteristics of respective security be simply visually verifiable.

For the solution of the proposed objective, use the characterizing properties of the claims independent 1 and 7.

For the present invention it is important that, for the verification of security features respective, arranged inside and / or on the documents and valuables and security, whose authenticity in the check using an appropriate check procedure with a corresponding checking device, the procedure is simple to operate, using to display the safety features both radiation in the spectrum of ultraviolet wavelength as the wavelength spectrum infrared, applying the Down conversion effect. Low conversion Down means the following effect by which a material luminescent, especially gifted, is excited by radiation, made in the non-visible spectrum and, depending on the endowment of the luminescent material, experience a jump in the energy band and, after the convergence of the energy state, it emits radiation in the visible radiation spectrum. This radiation it can be captured by the human eye with which the existence of security features on documents and Security and valuables to check.

In the generation of a luminescent effect, two different materials find application. On the one hand it it is a luminescent material with residual luminescence not perceptible, called fluorescent and, secondly, it is of a type of luminescent material that generates the effect of a residual luminescence, called phosphorescent.

For the use of features of security in documents and objects of security and value has no importance which of the two luminescent materials is used. Only the demonstration of the existence of characteristics is decisive of security.

For the excitation of characteristics of luminescent safety it is necessary to direct UV light on the luminescent safety features, something that until now is performed by using impractical fluorescent tubes. Due to their high power, said fluorescent tubes were subject to electricity supply and also had dimensions little manageable that did not allow a simple and practical use. Now in The present invention is important that by using diodes luminescent working in the UV spectrum there is the possibility of be able to build a checking device in one embodiment very maneuverable with small dimensions, for example, in the form of key chain. Hence the possibility of manufacturing for the first time a test device not subject to power and Transportable and easily usable.

The energy supply for the operation of the LEDs used can be performed, due to low consumption, compared to that of the tubes, completely using batteries, the so-called button batteries. Through this voltage supply ensures that the device check for verification of security elements Luminescent can be independent of location. Is remarkable as another advantage that the checking device it can be transported without problems and, due to its dimensions reduced and, consequently, at low weight, can be at available to anyone at any time, being said hand checking device, like many other utensils daily use.

It is important in the present invention that multiple diodes are arranged in an interconnect so that form a beam that, in a direction of radiation approximately likewise, they radiate their radiation located at least partly outside the visible wavelength spectrum. The use of multiple LEDs, for the purpose of radiation emission, located at less partly outside the visible spectrum, is that, because to the grouping of the emission of rays, a density is reached bright, which allows a more intensive visualization of The luminescent safety features.

Another essential safety feature of the present invention is that, between diode interconnection at least one luminescent diode is arranged which emits light in the visible spectrum, with what it finds application a first security feature, that is a optical operating indicator. Another additional device of security of the present invention optionally consists of another acoustic indicator also additional operation of the LEDs that work in the non-visible spectrum. By incorporation of these technical safety features is prevents intentionally or accidentally from occurring eye injuries of the ocular nerve from retinal burns, caused as a result of the lack of operation of the tear reflex of the eye due to unperceived radiation.

Another advantage of the present invention over of the fluorescent lamps used so far, is that life Useful light diodes is a multiple of the life of the fluorescent lamps. Especially with an on and off frequent fluorescent lamps, clearly decreases the useful life of the same, with which it is not possible to reach a useful life 1000 hours of operation for lamps fluorescent On the contrary, the life of the LEDs is a multiple 1000 hours of operation.

From there arise the advantages that in the present invention a test device can be manufactured independent of the power supply, long service life, Usable anytime, anywhere.

In this way, by performing this Totally new concept, which provides for the use of diodes UV lights (UV LEDs), it is reached for the application case this high flexibility Thus, UV light diodes are comparable in its constructive form and its electrical characteristics with diodes conventional luminous. LEDs for the spectrum visible (wavelength from 400 nanometers to 700 nanometers) and for the near spectrum (RI; wavelength from 700 nanometers to 1000 nanometers) have long been habitual. They are used in the technique mainly as indicator elements (blue LEDs, green, yellow and red) or in remote checks, barriers Photoelectric (IR LEDs). The requirement of LEDs increasingly shorter wavelengths is justified because the optical data storage density, for example, on CD or DVD, is growing with decreasing wavelengths.

For a long time it was not possible to manufacture blue shortwave LEDs, because there was no available appropriate technology for serial production. Only from About 5 years ago, there are appropriate LEDs of the Nichia company that fill this technological gap with the manufacture of blue light and laser diodes. Now, through the improvement of this technology has been possible to manufacture the first light-wavelength diode samples even more short.

These LEDs work in a spectrum of length wavelength of 370 nanometers and thus have a similar wavelength to which they have the commercial UV lamps (wavelength 375 nanometers)

The advantages of UV LEDs over a lamp UV fluorescent are:

Smaller dimensions (standard body of an LED: 6.2 mm high, approximately 5 mm in diameter), low absorption power of approximately 60 milliwatts, high performance Optical of approximately 750 milliwatts and a long service life of 2000 hours of operation approximately. It follows that the LED shows approximately a double life of the a fluorescent lamp, whose useful life, in addition, is reduced in a way clear due to the high frequency on and off.

Another advantage of light emitting diodes over the fluorescent tubes is that the light emitting diodes, in when they are put under tension, they immediately reach all their optical performance On the contrary, the fluorescent tube needs always a certain time to activate the existing gas and thus reach its light capacity and service availability. This entails the disadvantage of waiting time between moment of ignition and the first moment of tube availability fluorescent, and the disadvantage of electricity consumption clearly higher.

For proper operation of these LEDs a power supply between 3.5 volts and 4.5 is necessary volts Said power supply can be achieved by properly sized batteries for long life satisfactory

A uniform light intensity can achieved through the use of an amperage source constant for the feeding of the UV LEDs. With that, the Transistors used ensure that UV LEDs always exist the same voltage drop, resulting in use a uniform light intensity. By using a constant amperage source of this type, it is also possible to use battery voltages greater than 4.5 volts which, through the system electronic, are limited to the appropriate necessary values. With The data indicated above produces an electrical consumption of 10 milliamps approximately. Under these working conditions, according to the manufacturer's specification a life can be achieved Useful for approximately 2000 hours of operation. With the use of conventional alkaline batteries of the type LR44 (1.5 volts) This results in an operating time of 12 hours approximately. If it is taken for the verification of a document of security and value a time span of 10 seconds is a number of verification processes that are close to 4320 processes.

In order to take advantage of the different speed of diminishing luminescent colors individual applied as security features, the The present invention provides that the excitation for the emission of luminescent radiation, caused by infrared radiation or ultraviolet, is influenced by pulse procedures provided for the operating power of the LEDs used, so that, due to the characteristics of luminescent safety properly excited, stand out different colors on documents or valuables and of security. The reason for this changing color spectrum of the radiation emitted by the luminescent characteristics is the luminescent irradiation overlay of frequency zones different, conditioned by the use of different colors, whose coefficients of decrease are of different magnitudes. But it is convenient to use luminescent colors that clearly they present different decrease coefficients. In this way, the advantage is that in the pulsating or intermittent form and / or modulated from the power supply to the respective LEDs are produce radiation emission characteristics different from those safety features These characteristics manifest in which, for example, in the non-pulsating or non-modulated form of the voltage supply, both of at least two colors Different luminescent used present their maximum reflection. This results in a color scheme that appears with relation to the amount of security features applied and its intensity of reflection based on its reflective power and its coefficients of decrease. With pulsation procedures now running or with intermittent and / or modulated modification of the voltage supply of the LEDs occurs, also in direct function of this form of supply voltage, the infrared and ultraviolet irradiation on the characteristics of security. Ultraviolet or infrared radiation, which is emitted by solid semiconductor elements, by said reason, depends directly on the tension, because the same immediately reaches full radiation power when connected the corresponding tension and maintains it until the moment of disconnection Therefore, security features luminescent are irradiated with infrared radiation and ultraviolet in the form of the fed working voltage. Through the intermittent and / or modulated form of this power supply tension, reflection characteristics of colors Luminescent used for safety features are now captured by the eye based on their coefficients of decrease. When, for example, color A has only 1/10 of the reduction coefficient of color B is possible, with the shape flashing and / or modulating the supply voltage of the LEDs, influence the irradiation characteristics of color A so such that it, compared with the irradiation power of the color B, approaches zero. This results in an effect of reflection that allows to recognize only the color B. If now modifies the pulsation ratio of the working voltage in the sense that the pulsation ratio has periods of On clearly longer than the shutdown periods, the color A, which a moment ago presented a constant of irradiation clearly less than color B, again emits a radiation noticeable by the eye. This results in a combination of reflection frequencies depending on the conditions between colors A and B, so that the eye can perceive a color change of the luminescent colors irradiated

For example, color A is green and color B blue; in this way, in a non-pulsed voltage supply, the Reflection of security elements would be blue / green. In a way voltage supply now pulsating and / or modulated, in the change of the pulse conditions between voltage on and off, color A, that is green, becomes each time weaker and the blue color remains constant. Such modulation can be carried until the reflection of the green color has completely diminished. In this case, the color blue, due to its high decrease coefficient, would still emit radiation visible.

The present invention now provides that the modulation procedure for the working voltage of the LEDs optionally varies when checking documents or objects of value and security. This way you can check all the frequency spectrum of safety features Applied It is shown by a change of colors reflected, produced by the sum of the frequencies reflected.

Another alternative power supply results by the use of a DC / DC inverter. This IC is in condition of multiplying the voltage of a battery. In this way, it is possible develop an electronics for UV LEDs in which they are Only one or two batteries of type LR44 are sufficient.

This embodiment is alternative to the embodiment with the power source constant.

With reference to the design of the box for the installation of the UV LEDs and the respective power supply Multiple embodiments have been developed. A form of realization of said box is configured in such a way that, due to to its reduced dimensions, it can be carried on the key ring in the pants pocket, without disturbing the user. The ergonomics of UV LEDs prevent accidental activation when carried in the pocket. In addition, attention has been paid to the key for operation of the checking device be equally comfortable of Operate both right and left handed. One click clearly audible and perceptible also ensures that the user does not lead to carry out an accidental activation of the checking device.

The core box is made of copolymer of acrylonitrile-butadiene-styrene (ABS) through the thermoplastic injection molding process. In this it is preferred to use elastomeric elements so that the function of the checking device is not impaired by fall to the ground from waist or shoulder height, even on floors hard, for example, stone floors or the like.

The high resistance to breakage of the Checking device reached is another feature of security of the present invention. Another feature for the Safe operation of the checking device consists of that the design of the box is made in such a way that Closed and protected against splashing water. In addition, the LEDs are arranged in the box in such a way that scratching is prevented for outstanding elements and thus remains preserved in any moment the opening angle of approximately 10º for UV light and / or irradiated infrared.

Another embodiment of the present The invention provides that it is made as a fixed equipment. This UV LED lamp is equipped with a series of LEDs, to ensure Intense and uniform lighting. Optionally, this verifier It can be equipped with a UV filter. This filter can reduce visible parts of annoying blue light and thus enable better visibility of the luminescence. In addition, authenticity is restored of the color of the luminescence with respect to the UV lamp.

To enable during insertion into the check position the recognition of a product or object of value and security, it is planned to install a sensor proximity. Said proximity sensor turns on the power electrical for the LEDs when recognizing a product or object of Value and security. This way you can start the process of check already described above.

The UV LED verifier is therefore equipped with a sensor that recognizes if under the device Find a security document to verify. Only in this In case the UV LEDs light up. Such a sensor It could be done using a simple light barrier. The advantage of this solution is that the UV LEDs are only lit when they are needed. In this operation, the service life is increased clearly and exceeds in a multiple that of a fixed UV lamp, in the that such an operation is not possible. Also I know achieves lower energy consumption and less UV than in the usual permanent operation in UV lamps.

Another interesting possibility results from the combination of UV LEDs and infrared LEDs. In addition to the Luminescent features under UV light are used in form also increasing characterizing substances that, under radiation with infrared light, converge in the visible light spectrum (conversion ab or anti-stocks). Therefore it is convenient a combination of UV and IR LEDs because in this way both safety features can be checked.

Due to the development of this fixed device, both fixed checking devices and laptops

If a graphic element is found integrated security features, for the use of both spectral zones are verifiable both characteristics of security. With this, both different security features They differ by different colors. This is how it turns out simple and striking verification of the characteristics of security present.

The present invention is described by the following description of the figures, based on multiple forms of embodiment of the present invention. The figures show:

Figure 1, a sectional representation of an embodiment of the UV LED testing device and go,

Figure 2, a view above, according to the Figure 1,

Figure 3, a sectional representation of another embodiment, according to figure 1,

Figure 4, a sectional representation perpendicular, according to figure 3,

Figure 5, a sectional representation, by A-A, according to figure 3,

Figure 6, a sectional representation, by B-B, according to figure 3,

Figure 7, the interior structure of the test device, according to figure 3,

Figure 8, the interior structure of the test device, according to figure 4, and

Figure 9, the interior structure of the test device, according to figure 6.

Figure 1 shows a UV-IR LED pointer or indicator that in a box 5 contains UV LEDs 2, IR LEDs 3, LEDs in the visible spectrum 4 and batteries 5. Furthermore, in this representation of said embodiment of the present invention , an acoustic indicator 12 and a detector 9 can be seen. When the detector 9 is activated, the specified operating voltage, battery power 6 to the light emitting diodes 2, 3, 4 are supplied via the electronic system and excited The same to emit light. Also, by activating the detector 9, provided with an appropriate elastic force, the acoustic indicator 12 emits a signal. By means of said acoustic signal, as well as by means of the LEDs in the visible spectrum, it is ensured that non-visible radiations cannot leave the LEDs without emitting warning signals, both optical and acoustic. The emission of the optical signal is used to activate the closing reflex of the eye muscle. The emission of ultraviolet or infrared radiation by the UV-IR LEDs serves to excite the luminescent characteristics of the documents and valuables and security to be checked. Due to the excitation by ultraviolet and also infrared light, a Down conversion energy transmission that excites the radiation safety characteristics in the wavelength spectrum occurs in the safety features
visible.

Figure 2 shows a view above the embodiment according to Figure 1, in which the view above takes place from the direction in which the irradiation of the LEDs is directed. In this arrangement, several LEDs arranged in a concentrated state can be seen in the front of the pointer box 5
UV-IR

Figure 3 shows a representation in section of another embodiment of the present invention, in the that the combination of UV LED 2, IR LED 3 and LED in the spectrum of Visible wavelength 4 is shown in a single unit. They can see also in box 5 the electronic system 8 of the detector 9, as well as batteries 6 with contacts 7. The mode of operation of said embodiment corresponds mainly to the mode of operation of the operation described above.

Figure 4 shows a representation in section perpendicular to that of figure 3. In this form it can be seen Clearly the ergonomic design of the manual UV / IR LED pointer. The component arrangement box 5, battery 6 with contact 7 as well as detector 9 with cover 11 and the core, LEDs 2, 3, 4, are Sample clearly. On the underside of the box you can see an ergonomic handle 10. In addition, an opening 13 can be seen for housing a ring or a fastener similar to box 5. The detector 9 arranged inside the box is actuated by means of a water splash proof cover 11. In bliss representation can also be seen well, that a drive of the detector can only be performed when consciously exercised pressure on the cover 11 of the detector 9 located below Regarding the remaining box. This pressure requires a certain force, which ensures to prevent accidental actuation of the pointer of UV / IR LEDs.

Figure 5 is a sectional representation by A-A of Figure 3. In this representation presents the arrangement of four 6 batteries in box 5. Said batteries are used for the voltage supply of UV LEDs, IR LEDs as well as LEDs in the visible wavelength spectrum and of the acoustic operating indicator 12.

Figure 6 shows a representation in section, by section B-B of figure 3. In this case can be seen on the left side of the box 5 the handle 10, which is also shown in the lower left of the Figure 4. In addition, the detector 9 is shown in the middle, thus as the LED unit 2, 3, 4 for the LEDs. Additionally they can see parts of the electronic system 8.

Figure 7 shows the internal structure of this embodiment of the present invention. Fit analogous to figure 3, on the left side the collective representation for LEDs 2, 3, 4 with their connections. In addition, the detector 9 can be seen in the middle with the surrounding electronic elements 8. On the right side of said representation shows four 6-button batteries, connected via contacts 7 with the electronic system 8.

In figure 8, said representation is rotated 90º, with what is shown on the left side the joint unit for LEDs 2, 3, 4 with their contacts for connections to the electronic system needed. In the middle you can see a component electronic 8, behind which the detector 9 is positioned, recognizable by its highest structure. To the right of this is They have contacts 7 and batteries 6.

Figure 9 shows a front view of this inner part of said embodiment of the present invention. Centered, in the middle you can see the combination again of LEDs 2, 3, 4 as a single unit. Behind is willing the detector 9 and a component of the electronic system 8. In the area upper and lower contacts 7 with their connections can be seen to the stage.

The embodiments of the present invention thus described in any way should be construed as limited, but, on the contrary, they are only part of the multiple forms possible embodiments of the present invention.

Legend

one

UV / IR pointer

2

LED UV

3

LED GO

4

LED of the visible wavelength spectrum

5

Box

6

Drums

7

Contacts

8

Electronic system

9

Detector

10

Handle

eleven

Cover

12

Acoustic indicator

Claims (12)

1. Procedure for the verification of luminescent characteristics arranged inside and / or on products or objects of value and safety, the luminescent characteristics being excited for the emission of luminescent radiation through the use of radiation from solid electroluminescent semiconductor elements of the length spectrum non-visible wave, characterized in that the voltage supply of the electroluminescent solid semiconductor elements is carried out in pulsating or intermittent and / or modulated form and the radiation emitted by the solid semiconductor elements acts in conjunction with at least two safety features of different coefficients of decrease in such a way that, when changing the pulsation conditions of the voltage supply, different color combinations of the luminescent radiation irradiated by the safety features are presented to the observer. 2. Method according to claim 1, characterized in that ultraviolet (UV) radiation of a solid electroluminescent semiconductor element is used. 3. Method according to claim 1, characterized in that infrared (IR) radiation of a solid electroluminescent semiconductor element is used. Method according to one of the preceding claims, characterized in that a combination of ultraviolet radiation and infrared radiation is produced for the excitation of the safety characteristics from the solid UV and IR electroluminescent semiconductor elements arranged together in the testing apparatus, and / or a combined electroluminescent solid semiconductor element of UV / IR. 5. Method according to one of the preceding claims, characterized in that the irradiation of continuous and / or intermittent visible radiation performed using a luminescent element, preferably an LED, in the visible wavelength spectrum is performed at the same time as the irradiation from of solid electroluminescent semiconductor elements in the non-visible wavelength spectrum. Method according to claim 5, characterized in that, in addition to the optical indication of operation, an acoustic indicator of operation emits acoustic signals during operation of the electroluminescent semiconductor element. 7. Device for checking luminescent characteristics arranged inside and / or on products or objects of value and safety, comprising solid electroluminescent semiconductor elements whose radiation in the non-visible wavelength spectrum serves to excite the luminescent safety characteristics to be emitted Electroluminescent radiation, characterized in that the voltage supply of the electroluminescent solid semiconductor elements is carried out in a pulsating or intermittent and / or modulated manner, so that the radiation acts at least on two luminescent characteristics of different decrease coefficients, so that By changing the pulsation conditions of the voltage supply, different combinations of luminescent irradiation colors of the safety features are produced for the observer. Device according to claim 7, characterized in that an electroluminescent solid semiconductor element emits ultraviolet (UV) radiation. 9. Device according to claim 7, characterized in that a solid electroluminescent semiconductor element emits infrared (IR) radiation. Device according to one of the preceding claims 7 to 9, characterized in that solid UV and IR electroluminescent solid semiconductor elements and / or a combined UV / IR electroluminescent solid semiconductor element arranged together in the test apparatus emit a combination of ultraviolet radiation and infrared for excitation of luminescent safety features. Device according to one of the preceding claims 7 to 10, characterized in that a luminescent element, preferably an LED, emits continuous or intermittent radiation in the visible wavelength spectrum at the same time as the solid electroluminescent semiconductor elements are emitted radiation in the wavelength spectrum not visible. 12. Device according to claim 11, characterized in that the device emits acoustic signals during solid semiconductor element, in addition to the optical indication of operation.