BG97384A - Polychromatic electroluminiscent element - Google Patents

Abstract

The element is used in information, dispatching and technological tables and posters depicting controllable information. It has lower operating voltage and improved brightness of luminance of the individual monochromatic lighting zones due to the usage of chalcogenide layers. The probability of electric breakdown of the element is reduced and there are facilities for selective change of the lighting colour. It consists of a flat parallel glass substrate (1) having etched transparent conducting layers (2 & 3), shifted one towards the other, serving as lower electrodes of the monochromatic lighting zones, on each of which one electroluminiscient layer (4 or 5, respectively), one dielectric protection layer (6 or 7, respectively) and one each metal layer (8 or 9, respectively) being applied on each one in succession, serving as upper electrode. The electroluminiscent layers (4 & 5) are made of monochromatic luminophores, dispersed in an organic binder. The monochromatic luninophores can have blue max within 450 to 465 nm, green max within 505 to 525 nm, yellow max within 465 to 485 nm, orange max within 640 to 655 nm, and red max within 655 to 680 nm emission. The dielectric protection layers are chalcogenide of the As-S or Ge-S system, simultaneously vacuum evaporated separately or fully on electroluminiscient layers. The metal electrodes are fitted separately or fully on the chalcogenide layers in the illuminated zones.

Description

The invention relates to a polychrome electroluminescent element, in particular to an electroluminescent cell with at least two PBet regions, the color of which is selectively changed at intervals applicable to information, dispatching, technological and other panels for displaying controlled information.

Known electroluminescent element with a variable color of light from green to yellow, consisting of a flat-parallel glass substrate with a transparent conductive layer, at least one electroluminescent layer and a pair of electrodes located on the torn sides of the layer / 1 /. Dielectric layers can be arranged between the electroluminescent layer and the electrodes. When the electroluminescent layer is one, it is leaked with two microscopically distributed actuators that create two types of light centers with different energy levels. In the presence of two or three consecutive applied electroluminescent layers, each is doped with a different activator.

The disadvantages of this electroluminescent element are the significantly impaired light characteristics of the electroluminescent layer with two or three activators relative to those of a single activator layer, the higher operating voltage and the large difference in luminance of layers of different colors.

Another electroluminescent element is known, with regions of different light colors consisting of a pyramidal glass substrate, with a transparent electrode, an electroluminescent layer of a phosphor of one or the other color of light, and an upper metal electrode applied to each of the side and surfaces. . With a suitable switching of the excitation voltage between the lower transparent electrode and the upper metal electrode, light is emitted from the base of the pyramidal substrate in a color determined by the type of phosphor in the electroluminescent layer.

*** Disadvantages of this electroluminescentone elegant are: pyramidal glass substrate, unsuitable for use in information boards; higher operating voltage and difference in luminance in different areas.

A third multicolor electroluminescent element is known, consisting of a plurality of electrodes on a transparent glass substrate, on which, using a complex technique, electroluminescent layers of different luminescent material are deposited with the corresponding metal electrodes on them (3).

The disadvantages of this electroluminescent element are the sophisticated technology for producing monochromatic illuminated areas and high working power.

It is an object of the invention to create a polychromatic electroluminescent element with low operating voltage, increased luminance, reduced probability of electrical breakthrough, and compactly formed monochrome luminous regions.

The problem is solved by a polychromatic electroluminescent element consisting of a plane-parallel glass substrate with displaced, translucently etched transparent conductive layers, serving as the lower electrodes of the monochromatic luminous regions, each of which has a sequentially electroluminescent meta layer, serving as the upper electrode. The electroluminescent layers are made of monochrome electrolumines, dispersed in an organic binder and applied separately to the transparent lower electrodes of the illuminating regions. Monochrome electroluxes can be blue / J in the range of 450 to 465nm / green / 7 _max . in the range from 505 to 525nm /, yellow / 7 _{max in the} range from 565 to 585 nm /, orange / JN in the range from 640 to

655nm / and red / 7 ranging from 655nm to 680nm / emission.

The dielectric protective layers are chalcogenide of the As-S or Ge-S system, vacuum evaporated simultaneously individually or completely on the electroluminescent layers. The upper metal layers are individually or wholly located on the protective chalcogenide layers of the illuminating regions defined by the transparent lower electrodes.

The advantages of the polychrome electroluminescent element are the following: 1 / simple technology for making and compacting areas with different light colors; 2 / less operating voltage and increased luminance of the individual luminous regions due to the use of protective chalcogenide layers; 3 / reduced likelihood of electrical breakdown and 4 / the ability to selectively shine light at different time intervals.

An exemplary embodiment of the invention is shown in the accompanying drawings, of which:

Figure 1 is a schematic cross-sectional view of a polychrome electroluminescent element having a protective chalcogenid layer and an upper metal electrode disposed separately on the illuminating regions;

Figure 2 is a schematic cross-sectional view of a polychrome electroluminescent element having a protective chalcogenide layer and a top metal electrode disposed entirely on all illuminated regions.

The polychrome electroluminescent element / according to FIG. 1 / consists of a plane-parallel substrate 1 on which are disposed one by one the displaced transparent conductive 2 and serving for the lower electrodes, the electroluminescent layers 4 and 5 with different light colors, the dielectric protective chalcogenide layers 6 and 7 and the metal layers 8 and 9 serving as upper electrodes.

The polychrome electroluminescent element / according to FIG. 2 / consists of a plane-parallel substrate 1 on which disposed translucent transparent conductive layers 2 and 3 are disposed against one another, serving as electrodes, electroluminescent layers 4 and 5 with different light colors, a common dielectric protective chalcogenide layer 6 and a common metal layer 7 serving as the upper electrode.

The effect of the polychrome electroluminescent element according to the invention is as follows. When an exciting sinusoidal, rectangular, or pulsed AC voltage is applied to one of the transparent pipelay electrodes and the upper single or common upper metal electrode for a selected period of time, light is emitted by a color determined by the electroluminescent layer embedded in the electroluminescent layer. At another selected time interval, the excitation voltage is applied between one of the transparent lower electrodes and the upper other single or common upper metal electrode, and light is emitted in a color determined by another monochromatic electro-phosphor embedded in the electroluminescent layer. Thus, when switching the excitation voltage for a time interval, the polychromatic electroluminescent element can emit light of different color n to indicate specific color information.

the following examples illustrate the invention without limitation.

Example 1. The polychrome electroluminescent element of FIG. 3, a-d, topologically formed with two differently illuminating regions, consists of a plane-parallel glass substrate 1 on which two systems of transparent conductive layers 2 and 3-4 on the base of HaSnO ₂ with a thickness of 300 are etched to form the two illuminating regions. - 20 pt / FIG. 3, a /, deposited on both areas of the electroluminescent layers 5 with red light / J _c =

670 bp and 6 with green light = 515 bp and a thickness of 50 ^ 1 jum / FIG. 3,6 /, total dielectric protected I ^^ ly with thickness of 1.2jum / fig. 3, in / and separate metal electrodes / for the area with red light color / and 9-10 / for the area with green color of light / with thickness of 200-20 pt / FIG. 3, and /.

Example 2. The polychrome electroluminescent element of FIG. 4, a-d, topologically shaped with four differently illuminating regions ₍ consisting of a plane-parallel glass substrate 1 on which, for forming the four illuminating regions, θ is a system of transparent conductive layers 2-5 based on Sn0 _{2 with} a thickness of 200 ^ 20 nm (Fig. 4a) are applied to the four areas of the electroluminescent layers 6 with green light (~ _max = 515 pt), 7 with the boat light color / Λ _τ „ _νπ = 670 nm /, 8 s blue glow / Jk _Μςκο. = 455 nm / s 9 yellow Emitting / mm = 575 nm / and a thickness of 1 50i jom / Fig. 4, b /, a common dielectric zashtitenAs ₂ S ^ $ tallow 10 with Thickness 1,2jum / Fig. 4 in / common metal electrode 11 serving as an upper electrode with a thickness

D "

- ο 200 20nm / FIG. 4, g /.

When applying a sine, rectangular or pulsed AC voltage u _ef ^ 100-120 v in the frequency range from 400 to 1200Hz between the lower transparent electrode and the common upper metal electrode of the individual illuminating regions of the polychrome electroluminescent element, light is emitted at selected intervals. one or the other light color and specific color information is displayed.

Claims (4)

1. POLYCHROMON ele1'TrO.IUMi1 is an ESSENTIAL element consisting of! from a plane-parallel glass liner with a displacement of the Hellenic to another etched transparent conductive layer, a slug! for the lower electrodes of the illuminating regions, each of which has an electroluminescent layer, a dielectric protective layer and a metal layer serving the upper electrode in succession, characterized in that the electroluminescent layers are made of monochrome electroluminescenters, dispersed applied individually to the transparent lower electrodes of the illuminating regions. 2. The polychrome electroscentric element according to claim 1, characterized in that the monochrome electrolumines have blue (in the range from 450 to 465 ppm), green ( _with in the range from 505 to 525 nm), glutinous (Ά _{No. KC} in Goanpa) of 565 up to 535 am / hv in the range from 640 to 655nm / red and / _{»nm to} within the range from 655 to 680shi / feed A polychrome electroluminescent element according to claim 1, characterized in that the dielectric protective layers are chalcogenide systems As - S or Ge - s, vacuum evaporated simultaneously or completely on the electroluminescent layers. The polychrome electroluminescent element according to claim 1, characterized in that the upper metal electrodes are disposed individually or perpendicularly to the chalcogenide layers of the illuminating regions defined by the lower transparent electrodes.