MXPA06004849A - Electroluminescent system - Google Patents

Abstract

The electroluminescent system comprises an electroluminescent device (1) having a first, two-dimensional electrode (2) made of a transparent material. A layer (3,4) made of luminescent dielectric is assigned to each of the large surfaces of said first electrode (2). Said luminescent layers (3,4) are transparent and are made of materials that can emit light with different wavelengths. An electrode (5, 6) is assigned to each large surface of the luminescent layers (3, 4) opposite the common electrode (2). A support layer (7) which is also made of transparent material is located on the front side of said electroluminescent device (1). A voltage source (11, 12) is connected between two successive electrodes (5, 2, 6).

Description

ELECTROLUMINISCENT SYSTEM DESCRIPTION OF THE INVENTION The present invention relates to an electroluminescence device. The known electroluminescence devices of this type have a layer of a luminescent dielectric which is located between two electrodes. The color of the light emitted by the light layer during the operation of such a system is given by the composition of the material of the light layer. The color can not be changed for a given electroluminescence system. This circumstance restricts the possible applications of the electroluminescence devices. The object of the present invention is to eliminate this additional disadvantage and disadvantages of known electroluminescent devices. This object is achieved with the electroluminescence system of the generic type initially described according to the invention as defined in the characterizing part of claim 1. The examples of the embodiment of the present invention are explained in more detail below with reference to the annexed figures. These show: Figure 1 in a partially vertical section, Ref. 172612 the structure of a first embodiment of the present invention; Figure 2 in a partially vertical section, the structure of a second embodiment of the present invention; Figure 3 in perspective and greatly enlarged, the principle of a monochromatic screen based on the present invention; Figure 4 in perspective and greatly enlarged, the principle of a color screen based on the present invention; and Figure 5 in a vertical and greatly enlarged section, an extract of the system according to Figure 4, wherein this Figure 5 follows the course of the individual layers of the system in Figure 4 after this device has been embedded. The present electroluminescence system comprises an electroluminescence device 1, referred to later simply as an EL device. This device EL 1 has a first flat electrode 1, that is to say cohesive, of an electrically conductive and also transparent material. Materials of this type are generally known. Each of the large surfaces of. this first electrode 2 has a luminescent one-layer 3 or 4 of a dielectric. These layers of light 3 and 4 are designed as cohesive layers. The materials of these light layers are selected so that they can emit light with different wavelengths. Materials of this type are also generally known. Assigned on the large surface of the light layers 3 and 4 facing away from the common electrode 2 is an additional electrode 5 and 6. These electrodes 5 and 6 are also transparent. The material of at least one of the light layers 3 and 4 is transparent. For example, the material of the first light layer 3 may be transparent while the material of the second light layer 4 is opaque. In this case the EL device could emit light only in the direction indicated by the letter A, where the electrode 5 attached to the outside of the first light layer 3 as established above is also transparent. However, it is more suitable if the second light layer 4 and the electrode 6 attached to its outer surface are transparent. This device EL 1 emits light only in the direction indicated by the letter B if the first light layer 3 is opaque. There may also be applications in which light will be emitted from both, large surfaces of the device.- EL 1. For such. case the light layers 3 and 4 and the three electrodes 2, 5 and 6 must be transparent. • Assigned on the large surface of one of the external electrodes 5 or 6 is a support 7 in which the EL 1 device is attached. This support 7 is in most cases made of a transparent material because in most cases of application it forms the front of the present device • EL. A . modality of the present device is described below in which the. Support 7 is not transparent and constitutes the back of the EL device 1. The support 7 may be rigid or flexible. Furthermore, the material of the support 7 can be such that this material can be embedded, in particular in three dimensions. This measure additionally extends the application area of the present EL device. The EL 3 and 4 layers can only be illuminated when a corresponding electrical voltage is applied to the electrodes 2 and 5 or 2 and 6 / between which the respective EL 3 and 4 layers are placed. To this end the present EL device has a delivery device 10 designed accordingly, which serves as a device for controlling the luminescent layers 3 and 4 of the electroluminescence device 1. The first embodiment of such a delivery device 10 shown in FIG. . Figure 1 comprises two voltage sources 11 and 12 which are connected in series. At the common point 13 of the sources connected in series 11 and 12 is connected at one end a conductor 14, -the other end- of which is connected to the common electrode or -first 2 of the.

EL device 1. The other terminal of the first voltage source 11 is connected via a first switch 15 to the second electrode 5 which is on the outside or rear of the first layer EL 3. The other terminal of the second voltage source 12 it is connected via a second switch 16 to the third electrode 6 which is on the outside or in front of the second layer EL 4. Depending on which of the switches 15 and 16 is conductive, the EL device can emit light with the color of the first layer 3 and with the color of the second layer EL 4. If both switches 15 and 16 are conductive, then both layers EL 3 and 4 emit light. The result is that the EL device emits light with a color which arises from the addition or subtraction of the colors of the EL 3 and 4 layers. It should be clear that the electroluminescence device 1 can have more than two transparent light layers and cohesive (not shown) that are placed on top of each other. In this case, a wide-area electrode is placed between two adjacent light layers in each case. These intermediate electrodes are also transparent. The free surfaces of the outer light layers are also each equipped with an electrode, at least the front electrode 5 is transparent. A voltage source is connected every two electrodes as shown in Figure 1 so that the voltage sources form a cascade. Figure 2 shows a second embodiment of the delivery device 20. This delivery device 20 has only one supply source 21 to which it is. parallel connection a potentiometer 22. The first terminal of this supply source 21 and therefore also the first terminal of the potentiometer 22 is connected via a first conductor 23 to the rear electrode or second 5 of the device EL. The second terminal of the supply source 21 and therefore also the second terminal of the potentiometer 22 is connected via a second conductor 24 to the rear electrode or third 5 of the device EL 1. The output point 25 of the potentiometer 2 is connected via a third conductor 26 to the common electrode or first 2 of the EL device. Depending on whether the output 25 is at one end or the other end of the resistance body 27 of the potentiometer 22, the full voltage of the source 21 is applied in one layer EL 3 or the other layer EL 4. In the position of the outlet 25 shown in figure 2 both the EL 3 and 4 layers are under voltage so that the two layers EL 3, 4 are illuminated. The result is that the device EL 1. emits light with a color which arises from the addition or subtraction of the colors of the two layers EL 3 and 4. The fact that the color of light. can be selected in this way offers the possibility of., create • screens to show images. Such screens are suitable in particular for the reproduction of static images. Such screens are also suitable for the reproduction of changing images if the frequency of the image change is not high. Fig. 3 shows in perspective the principle of such device 30 using the example of a black and white screen. Figure 3 shows an extract of the flat EL layer 3. The electrode 31 on the front of this device 30 comprises parallel strips 311, 312 of an electrically conductive and transparent material known per se. In the present case this set of strips 311, 312 etc. runs vertically. The electrode 32 of this device 30 behind the layer EL 3 also comprises parallel strips 321, 322, etc. of an electrically conductive and transparent material known per se. In the present case this second set of strips 321, 322 etc. run horizontally Figure 3 shows the lower left corner of such black and white screen 30. The delivery device (not shown) for this EL device 30 is constructed in a known manner so that it can apply an electrical voltage in succession to the electrode strips . Individuals • 311, 312 etc. and 321, 322, etc. in a pre-specified way. At a particular time the voltage is applied to the electrode strips 311 and..3.12. ' In. • this time only this area C of the EL 3 layer which is located between-the intersected electrode strips 311 and 312 is under the effect of voltage. Consequently, only this area C of the EL 3 layer is illuminated at this time. If the supply device 10 applies the voltage in the following time to the electrode strips 312 and 321, then only the area D of the layer 3 is illuminated etc. In this way the lighting points C, D etc. they can be moved under control over the total surface of the EL device. Figure 4 shows in a greatly simplified form an extract of the lower left corner of a color screen 40 - which has the support layer 7. It is suitable if the surface facing the device EL 1 of this support 7 is reflective or supports a reflective layer. It is generally known that, for example, on a screen any of the colors can be achieved by a combination of yellow, red and blue colors. The present device EL 40 consequently has three cohesive layers and. transparent that are placed on top of each other of a 3G electroluminescent dielectric which can illuminate red, a 3R electroluminescent dielectric which can illuminate blue and an electroluminescent dielectric .3B which can illuminate white. To keep the diagram in Figure 4 as clear as possible, the layers 3G, 3R and 3B in Figure 4 are -showed only by the reproduction of these references. • The individually pigmented layers 3G, - 3-R and 3B are controlled in the manner explained in connection with Figure 3. In contrast, with the EL device 40 according to Figure 4 however the electrode strips are - they place behind each other are required to control all three luminescent dielectrics 3G, 3R and 3B. These three luminescent dielectrics 3G, 3R and 3B are such that they can emit light of different wavelengths. In Figure 4 two sets of electrodes are shown which are necessary to control only a single point C of the front surface of the screen. The subsequent description is applied to the other points (pixels) of the screen surface in a similar manner. From Figure 3 the first vertical strip 311 of the front electrode 3 has been used for Figure 4. Behind this vertical strip 311 is a 3G EL layer.Behind this layer the 3G is the first horizontal strip 'G321 and consequently the prefix G is applied to the number of this horizontal strip G321.To control the pixel C so that it illuminates, the necessary voltage is connected to the strips-311 and G321. the horizontal strip -G321 is the EL layer 3R which similar to the EL 3G layer is flat and which also - It has assigned to this' several strips of electrode both vertical and horizontal. Behind the layer 3R is a vertical strip R311 and consequently the prefix R is given to the number of the horizontal strip R311. So that the pixel C at this point lights up, the voltage control is connected to the electrode strips G321 and R311. The horizontal strip G321 therefore serves not only to control the 3G EL layer but also to control the EL 3R layer in the same manner as described in connection with the common electrode 2 in FIG. 1. Behind the vertical strip R311 is the flat layer 3B and behind this the layer 3B is arranged to the horizontal strip B321. So the pixel. C - at this point it is illuminated, the voltage control is connected to the electrode strips B321 and R311. The vertical strip R311 serves not only to control the EL 3R layer but also to control the EL 3B layer in the same manner as described in connection with the common electrode 2 in Figure 1. The horizontal strip B321 nevertheless serves only as the . rear electrode 6 in figure 1. If the pixel C is to display a color which arises from a combination of the base colors, then the corresponding voltages are applied to the related electrode strips in a known manner. The control with the intersection electrodes. Similar to strips can also be called a matrix control. However, it is possible to control the transparent light layers 3G, 3R and 3B by pixels. Such pixel controls are also known per se.

Furthermore, the present system can be designed so that it can not only flex but also be formed in three dimensions, for example, stretched or still embedded. Figure 5 shows an extract of an embossing point of the device EL 40 which emerges from the representation in figure 4. The extract shown in figure 5 from the embossing point of the flat screen 40 comprises two sections 28 and 29 which enter them enclose an angle of 90 °. This extremely large flexibility of the EL 40- device, where the bending radius can be in the area of even less than 1 mm, is possible because the material of light layers 3G, 3R and 3B is very flexible and the individual layers - ie both the electrodes and the light layers of the screen, adhere to each other in a non-displaceable manner during the bending process. This technology is described in detail in a patent application WO 03/037039 by the same owner. In addition to the representation in FIG. 4, the screen 40 according to FIG. 5 has a cover layer 34-to which it is applied to the external electrode 311. - • The screens of the type described therein. point . They have the advantages that they are not. sensitive to contact, which flex and can still be embossed and which can be produced in conventional printing processes, for example in screen printing.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (10)

CLAIMS Having described the invention as above, the contents of the following claims are claimed as property:

1. Electroluminescence system, characterized in that it comprises an electroluminescence device which has a first flat electrode of a transparent material, because assigned to each of the large surfaces of this first electrode is a layer of luminescent dielectric, because at least one of these layers of light is transparent and because a second electrode is assigned to the large surface of the related light layer facing away from the common electrode.

2. System according to claim 1, characterized in that the electroluminescence device has more than two transparent light layers that are placed on top of each other, because between each two layers of light a transparent electrode is arranged and because the large free surfaces of the outer light layers are also equipped with an electrode.

System according to claim 1, characterized in that at least the electrode located on the front of the electroluminescence device is made of a transparent material.

4. System according to claim 1, characterized in that the light layers are made of materials which can emit light at different wavelengths.

5. System according to claim 1, characterized in that the extensive electroluminescence device has at least one point with a deformation of three dimensions, because this deformation has a radius which is less than 1 mm, and because at this deformed point it is connect at least two sections 28; 29 of the EL device, between which extends an angle el. which can be equal to 90 °.

6. System according to claim 1, characterized in that it comprises a device for controlling the luminescent layers of the electroluminescence device.

7. Electroluminescence system, characterized in that it comprises an electroluminescence device with at least one layer of a luminescent dielectric, because one electrode is assigned to each of them. large surfaces of. This layer of light, because the related electrode is designed as a set of parallel strips of an electrically conductive material, because the directions of. -these sets of strips are 'perpendicular to each other and because a control device is provided- which is designed so that the. Electrode strips can be individually connected to a power source.

8. System according to claim 7, characterized in that the light layer is designed as a cohesive layer. . . .

9. System according to claim 7, characterized in that the electroluminescence device has several transparent luminescent dielectric layers that are placed one above the other, because the luminescence dielectrics of the light layers are such that they can emit light of different lengths of wave, because, between each two layers of light a strip electrode is arranged and because the free surfaces of the external light layers each have a strip electrode.

10. System according to claim 7, characterized in that a reflecting layer is assigned to the back of the electroluminescence device and because the reflected surface of this layer faces the light layers of the electroluminescence device.