DE2252398A1 - METHOD FOR OPTICAL DISPLAY OF INFORMATION AND ELECTROOPTICAL DISPLAY DEVICE FOR CARRYING OUT THE METHOD - Google Patents

Description

Process for the optical display of information and electro-optical ^ display device for implementation

of the procedure

The invention relates to a method for the optical display of information, in which a medium, its optical properties change through an electrical potential, irradiated and an electrical potential applied to the medium is, and it also relates to an electro-optical ^ display device for performing the method.

Electro-optical display devices are already known. So z. In U.S. Patent No. 5,322,485, one such Described display device that has two electrodes arranged parallel to one another, at least one of which is transparent is, and between these has a thermotropic organic compound, the molecules of which are thread-like. the The optical properties of this connection change when an electrical potential is applied and when an electrical potential is applied Field between the two electrodes, the originally opaque connection becomes transparent. This change is presumably to a reorientation of the thread-like molecules under the influence of the applied potential. The change in the optical properties is thus expressed in changed light transmission or reflection properties.

The known devices of this type prove to be useful, but have the disadvantage that it is due to the fact that their effect is based on the influence of the visible light passing through or reflected, with their help is not possible, at the same time another, on the opposite side of the display device to the viewer to radiate the image through this device and make it visible.

The object of the invention is to provide ways and means with the help of which information is displayed optically as well as additional radiographic images can be viewed at the same time.

309818/1088

The invention is based on the knowledge that the object can be achieved in that light-permeable substances are precisely defined Type excited to fluorescence and the generated fluorescence radiation is selectively quenched.

The invention relates to a method for the optical display of information, in which a medium, its optical Properties change due to an electrical potential, irradiated and an electrical potential is applied to the medium, which is characterized in that the medium an electrically conductive solution of a chelate complex with a metal which fluoresces when exposed to UV light Rare earths, whose fluorescence is quenched by an electrical potential, and this solution with UV light irradiated.

The invention also relates to an electro-optical display device to carry out the procedure with

a) a cell with two spaced apart transparent, electrically conductive walls that contain a medium contains, the optical properties of which change due to an electrical potential, ■

b) a device for applying an electrical potential between the cell walls,

c) a radiation source and

d) a device with the help of which the rays of the radiation source can be directed into the cell,

which is characterized in that the medium located in the cell consists of an electrically conductive solution at one Exposure to UV light using fluorescent chelate complexes

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a rare earth metal, the fluorescence of which is quenched by an electrical potential, and the radiation source consist of a UV light source. '

The invention achieves that the display of information can be done with the help of an always transparent device, so that the simultaneous viewing additional images is made possible.

According to the invention, the fluorescence of fluorescent substances is precisely defined by the application of an electrical Field deleted. The fluorescence quenching with the help of chemical substances, e.g. B. by using oxygen or Iodine is already known. To carry out the method of the invention, however, the fluorescence quenching is chemisehem Paths unsuitable, as there is no recovery when using chemical agents, i. H. no recurrence of fluorescence, or at best only a very slow recovery takes place. In optical displays, this recovery, i.e. H. the return the fluorescence, but take place in real time, otherwise the time interval between the removal of the fluorescence quenching causative agent and the return of fluorescence is too great. According to the invention it is achieved that the fluorescence returns almost instantaneously after removal of the fluorescence quenching electrical potential.

To carry out the method of the invention is to a luminescent organic medium while being exposed to fluorescence activating radiation applied electric field and suppressed in this way the fluorescence. As luminescent organic media are the most varied of carbonate complexes with rare metals Soils that fluoresce when exposed to ultraviolet radiation are suitable. The fluorescence that occurs can be selective and repeated by applying an electric field

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to be deleted.

The electro-optical display devices according to the invention are simple and reliable devices that are characterized by very low energy requirements. The response time of the display devices according to the invention is fast and the devices show no adverse light scattering and are also transparent so that additional images made visible by fluoroscopy can be viewed.

The invention is illustrated in more detail by the accompanying drawing, in the represent:

Fig. 1 shows an electro-optical display device according to the invention in a scheme,

Pig. 2 shows an embodiment according to the invention with a cross-grid cell arrangement that can be connected to an electrical potential in the scheme and

Fig. 3 shows an embodiment of the invention with a for Numerical display suitable design in the scheme.

The cell 10 shown in Fig. 1 has two transparent, electrically conductive walls 11 and 12, which by electrically insulating spacers 13a and 1Jb from each other are separated. The walls 11 and 12 can be made of conventional known, comparatively solid, transparent, electrical conductive materials exist, e.g. B. made of electrically conductive polymeric substances or electrically conductive glasses. Transparent substrates with transparent conductive coatings applied to them are also suitable, ζ. Β. Glass substrates coated with indium oxide. For the sake of simplicity, the walls are shown in FIG 11 and 12 are shown as transparent moldings which have transparent conductive coatings S ^ and S2, respectively. Between

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A luminescent organic medium 14 of the type described in more detail below is accommodated in walls 11 and 12. The electrically conductive walls 11 and 12 are connected to an energy source 15 which is a polarity reversal switch 16 has. A light source 17 which emits ultraviolet radiation is also connected to the cell 10 » comprises the means for directing the radiation into the medium 14 located in the cell 10. To prevent through the ultraviolet radiation damages the eyes of the viewer, there is an ultraviolet filter above the cell 10 arranged. In Fig. 1, the light source is 1? although arranged on the side of the cell 10 facing away from the viewer, but corresponding results can also be achieved when the light source 17 is on the same side of the cell 10 on which the viewer is also located, is arranged. The energy of the ultraviolet light source can be very different, wherein the brightness of the luminescence varies directly as a function of the radiant energy. Ultraviolet light sources with a Output power of about 5 to 150 watts are suitable.

During the operation of the electro-optical display device according to the invention, the ultraviolet radiation is directed into the Zel le 10 in order to stimulate the medium 14 to fluoresce in this way. By switching on the electrical energy source 15, the fluorescence can be extinguished either on the wall 11 or 12, depending on the polarity. This quenching effect is presumably the result of an injection of electrons at the cathode. Provides z. B. S ^ represents the cathode, the fluorescence on the wall 11 is extinguished and the viewer sees no color. If S ^ is made by reversing the polarity to the anode, the fluorescence returns on the wall 11, with a corresponding fluorescence quenching on the wall 12. If the electrical energy source 15 is switched off completely, the fluorescence returns.

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In the embodiment shown in Fig. 2, an electrically conductive cross-grid cell 20 provided with electrical connections is shown, which has transparent walls 21 and 22 which are spaced apart at a distance d (which is generally about 1 to 50 microns) by spacers (not shown) are separated. The inner surfaces of the walls 2T and 22 carry electrically conductive strip-like parts 23a, b, c and d b '/, u. 24a, b, c and d. The conductive strips on the wall 21 are arranged orthogonally to the conductive strips on the wall 22 and in this way form an xy grid. Each of the conductive strip-like parts 23a, b, c and d or 24a, b, c xmd d icL is provided with electrical leads 25a, b, c and d or 26a, b, c and d. This arrangement enables certain parts of the grid to be electrically connected. Is z. If, for example, a potential difference is applied between the conductive parts 23b and 24d during the irradiation of the cell with UV light, the fluorescence is only extinguished in the area in which these two parts overlap. When suitable signal circuit are solid state electronic systems for the selective energy supply of large-size display panels of this type, and for displaying alphanumeric information, ie by Iumineszierende, arranged in rows and columns dots formed letters and numbers, in real time, that is, within time intervals that immediately by the observer as can be felt . Is z. B. a computer or a similar electronic device that work with transistors and / or diodes instead of vacuum tubes used, pairs of conductive strips can be supplied with energy according to the computer program, which leads to the fluorescence at the intersection of these pairs of strips suppressed and a series of points are generated with the formation of numbers and / or letters which are determined by the computer program.

In the embodiment shown in Fig. 3 of the electro-optical

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see display device according to the invention will as well as at those in the Pig. 1 and 2 illustrated embodiments of two spaced apart transparent, electrically conductive walls formed a cell. For a better overview, cLie walls are not associated in FIG. 3 Position shown to the structure of the conductive parts of the digital electrode 31, which forms a wall of the cell, clearly to be able to represent and explain clearly. The other wall is referred to as the common electrode 32. This design proves to be suitable for displaying numbers and numerical information. The circuit diagram shown enables a successive selective power supply to the cell to display the numbers 0 to 9 in a repeated sequence.

The circuit shown in Fig. 3 consists of a source of negative current surges and a group of electronic ones Components for the selective power supply of combinations

One of the electrodes a to g. When / pulse generator 33 is a device that sends out electronic pulses or signals of a single voltage at constant intervals and in the system shown, the required counter-voltage supplies to attract the dye molecules and their diffusion away from the electrode. The time pulse generator 34- consists of a device containing a number of electrical Generates pulses of uniform width and distribution. The counter 35 represents a device which is a combination supplies electrical pulses in a non-random order, bo that z. B. the number 2 to the number 1 and the number O follows the number 9. The decoder 36 supplies the from the counter generates pulses of the appropriate voltage and polarity and sends them in the correct order to the digital electrode inlet lead.

In the absence of external ones entering the counter cycle Signals veroor'-rU the time pulse generator 34- the counter 35 with

3 G 9 8 1 8/1 Ü fc b BAD ORIGINAL

Voltage pulses of the same amplitude and time intervals (the pulse rate can be set by changing the capacitance and the resistance of the device 54 · to a certain Time constant t - HC). To form numbers on the scoreboard the fluorescence of different combinations of electrodes is suppressed in a progressive from 0 to 9 Sequence and in any repeatable sequence. So z. B. the number 0 is formed when the electrode g tine fluorescence quenching voltage and the other electrodes a to f continue to fluoresce. In a corresponding manner, for. B. the number 1 formed when only b and c retain their fluorescence.

To accelerate the recovery time, an opposite or positive potential Vg is applied as soon as certain individual electrodes of the digital electrode have been negatively charged and a new number display is to be generated. The usual electrode In contrast, 32 is always switched positive and only through the circuit, a selectively pressurized electrode becomes more negative upon fluorescence quenching; otherwise is located the digital electrode is at ground potential.

To avoid slow recovery times as a result of molecules diffusing away from an electrode, counter pulses are continuously supplied by the single pulse generator 33. The * single pulse is a time signal of short duration and the short pulses are delivered in the event of a hatred that is imperceptible to the viewer and cause fluorescence suppression and recovery. The reoxidation of suppressed molecules then takes place a short distance from the digital electrode before you wander into the liquid Hasse. A potential V ₁ is therefore applied to all 7 components of the digital electrode, regardless of the potential supplied to generate numbers

The luminescent organic medium present in the cells of the electro-optical display device according to the invention consists from a solution of a chelate complex with a metal

309Ö18 / 1066 originally inspected

the rare earth, which fluoresces when it is ultraviolet Exposure to radiation. The use of β-diketone chelates of metals has proven to be particularly advantageous Proven to be rare earths.

Typical suitable chelate complexes are those of the following Formula:

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where mean:

a cation of valence n, where η is an integer from 1 to 6, preferably from 1 to 3,

a rare earth metal with atomic numbers 57 to 71 and 89 to 103, d. H. a metal of the lanthanides and the actinides and

Lig is a ß-diketone ligand, generally known as the 1,3-dioxocarbonyl component can be referred to, it being possible for these ligants to be identical or different and are bound in chelate form to the rare earth metal.

The chelate complexes which can be used according to the invention can by the following more detailed structural formula can be reproduced:

_Λ η +

in which Q, η and M have the meaning given and in which

30 * 818/1068

R, R ¹ and R ' ¹ , which may be the same or different, represent monovalent hydrocarbon radicals, e.g. B. alkyl, aryl, alkaryl, aralkyl or cycloalkyl radicals or hydrogen halide, preferably fluorohydrocarbon radicals or heterocyclic radicals,

where R, R ¹ and R ¹ · generally have no more than 10 to 12 carbons and are free of aliphatic unsaturation, and

where R ^{1 can} also mean a chlorine, bromine or iodine atom or a cyano radical.

The radicals R, R ¹ and R ¹ 'can also be substituted with non-interfering functional substituents, e.g. B. with one or more halogen atoms with an atomic number of 9 to. 53ι J & it one or more hydrocarbon radicals of the specified type, with one or more hydrocarbon ether or thioether radicals, the hydrocarbon component of which has the meaning given, with one or more hydrocarbyloxycarbonyl radicals, ie Garboxyesterresten, or mono- or dihydrocarbylaminocarbonyl, ie carboxamido radicals, in which the hydrocarbon component in each case Has given meaning, or with one or more Hydrocarbylcarbonyl.- or -thiocarbonylresten, in which the hydrocarbon component has the meaning given.

The cation component of the ghelate complexes which can be used according to the invention and the trivalent, octacoperdinative metals of the rare earths can consist of customary known cations, for example those of the elements of groups IA and IIA of the Periodic Table, for example Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Gs ⁺ , Be ^, Mg ²⁺ , Ga ²⁺ , Sr ²⁺ J Ba ²⁺ or the ammonium ion (HH ^ ⁺ ), or from substituted aminium and ammonium radicals of any mono-

309818/1086

- ΊΟ "-
or polyamines of the following formulas:

E '" ₄ N ⁺ , E ¹¹¹ HH ⁺ , and

(CIH ₂ ) X NR ₃ ,

wherein the radicals R ¹¹¹ , which can be the same or different, are monovalent, optionally substituted hydrocarbon radicals with usually not more than 14 carbon atoms, for. B. alkyl, aryl, cycloalkyl, aralkyl or alkaryl radicals.

In the di-, tri- and tetrasubstituted ammonium cations, two or more of the radicals R ¹ ″ can be linked to one another to form a mono- or polycyclic nitrogen-containing heterocycle including the ammonium nitrogen atom. If two or more of the radicals R ¹ ″ are connected to one another, the bond can be effected by bridging members interrupted by oxygen, nitrogen or sulfur atoms with the formation of mono- or polycyclic oxaaza, diaza and azathia heterocycles including the ammonium nitrogen atom.

Furthermore, the radicals R ¹ ″ can be substituted with a meaning not specified in relation to R, R ¹ and R ¹¹ .

That present in the chelate complexes which can be used according to the invention Rare earth metals can be any metal

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be of the lanthanide or actinide series, d. H. so a rare one Earth transition metal with atomic number 57 to 71 or 89 to 103, namely lanthanum, oer, praseodymium, neodymium, promethium, Samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, actinium, thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium, Berkelium, Californium, Einsteinium, Fermium, Mendelevium, Nofrelium or Lawrencium.

The ligand component of the chelate complexes which can be used according to the invention with the trivalent, isctacoordinative metals of the rare earths can be very different and it can be z. B. are connections of the following basic structure:

0 " 0
II ^H Il
R - G - C - 0 - H "

_R ,

wherein E, R ¹ and H ^{11 have} the meaning given.

Typical suitable ligands are e.g. B. the following connections:

Dialkyl-β-diketones, e.g.

Pentane-2,4-dione,
Hexane-2,4-dione,
Heptane-2,4-dione,
Heptane-3 ♦ 5-dione,

9-methyloctadecane-8,10-dione,

Tricosan-11,13-dione,

1 » 1 » 1 > 5 »5» 5-hexafluoropentane-2,4-dione, 1,1,1-trifluoropentane-2,4-dione and 1,1,1,19 »19» Ί9-hexafluorononadecan-9 , 11-dione;

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Alkylaryl-ß-diketones, ζ. Β.

1-phenylbutane-1,3-di one, 1-phenyl-4,4,4-trifluorobutane-1,3-dione, 1-Ehenylundecan-1,3-dione, 1- (3,4-dimethylphenyl) -2-methyltridecane-1,3-dione, 1- (4-methoxyphenyl) -4,4,4-trifluorobutane-1,3-dione, 1- (2-thienyl) -4,4,4-trifluorobutane-1,3-dione, 1- (4-nitrophenyl) -4,4,4-trifluorobutane-1,3-dione, 1- (3-nitrophenyl) -4,4,4-trifluorobutane-1,3-dione and 1-phenyl-2-trifluoromethyl-4,4,4-trifluorobutane-1,3-dione or

Diaryl-β-diketones, e.g. B.

1,3-diphenylpropane-i, 3-dione, 1,3- (2,4-dimethylphenyl) propane-1,3-dione, 1-phenyl-3- (2-pyridyl) propane-1,3-dione, 1,3-di (4-pyridyl) propane-1,3-dione, 1- (4-methoxy) -3- (4-nitrophenyl) propane-1,3-dione, 1,3-di (4-nitrophenyl) propane-1,3-dione, 1,3-didurylpropane-1,3-dione, 1 -Furylbut an-1,3-rdi on, 1-thienylbutane-1,3-dione, 1-puryl-3-phenylpropane-i, 3-dione, 1-puryl-3-thienylpropane-1,3-dione, 1,3-difurylpropane-1,3-dione, 1,3-dithienylpropane-1,3-dione and 3-methylpentane-2,4-dione.

The size of the ligand present in the chelate complex has one Influence on the effectiveness of the system. The ligand component absorbs the ultraviolet radiation and transfers the energy on the rare earth metal, which then fluoresces. Larger ligands can therefore increase effectiveness through absorption from more UV radiation. Since the ligand also determines the absorption maximum of the system, you can select suitable

309818/106 6

Ligands ghelate complexes that "absorb at a certain wavelength, be tailor-made.

Fluorescent substances which can be used according to the invention are z. As described in U.S. Patent 3,254,106.

A wide variety of electrically conductive solvents can be used to produce solutions of the specified chelate complexes, as well as numerous dielectric solvents which contain an electrically conductive agent. Typical suitable solvent systems have a specific lumen resistance of usually less than about 1 0 ohm. Typical suitable solvents are e.g. B. to ghelates inert organic liquids, such as alkanols, z. B. methanol and ethanol, halogenated hydrocarbons, e.g. B. dichloromethane and dichloroethane, aromatic hydrocarbons, e.g. B. benzene and substituted benzenes, cyclic ketones, e.g. B. tetrahydrofuran, alkylformamides, e.g. B. dimethylformamide, cyclic dioxides, e.g. B. p-dioxane, as well as methyl sulfoxide, acetonitrile, bis (2-methoxyethyl) ether and pyridine. The solvents can be used both alone and in combination with one another.

Many solvents are sufficiently electrically conductive by themselves, whereas others in combination with a conductive agent, d. H. that is, an agent imparting electrical conductivity is better suited. Typical for this one Suitable additives are a number of ionic salts that act as current carriers. The has proven to be particularly advantageous Use of organic salts, e.g. B. of non-disturbing

Proven onium compounds. Typical suitable such compounds with an organic cation are e.g. B .. a wide variety of ammonium and imonium compounds, z. E. Benzyltrimethylammonium ^ odide, Tetrabutylammonium oxide, tetrabutylammonium perchlorate and tetrapentylammonium chloride, also carbonium compounds, e.g. "B. tritylium perchlorate, oxonium

309818/106 6

ties, ζ. B. Me tlioxypyryl iumper chi orate, sulfonium and Thionium compounds, ζ. Β. Trimethylsulfonium iodide as well their mixtures.

The concentration of conductivity agent "is in the Hegel 0 "to about 1.5 moles per liter depending on the type of solvent used. The solvent system is preferably so highly conductive that the volume resistivity is less than about 1.5 χ 10 ohms.

The concentration of rare earth metal chelate complex can vary from about 0.5 to 2 molar and is only low Influence on conductivity. When reducing the concentration of ohelate however, the response time usually increases.

As mentioned earlier, the distance between the cell walls can be to be different. The electrical potential applied to the luminescent medium generally varies as a function with the distance to the wall. The minimum voltage required depends not only on the distance between the cell walls, but also on, if applicable existing impurities. The theoretical minimum required for a particular system is equal to this Redox potential of the chelate complex used. However, the actual potential required can be greater than the theoretical one Value. In any case, the actually required potential can easily be determined. Useful results are achievable if the cell wall distance and the applied potential generate an electric field, the intensity of which is about 100 to 700 volts / cm.

For a typical, electrically connectable cell district of about 1 cm, the response time for fluorescence quenching is 1 millisecond or less when the current pulse is applied Acts for 1 millisecond and is 1.5 to 2.8 volts direct current. The recovery times are in the order of

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wa 10 to 20 milliseconds. For certain applications it can prove to be expedient to increase the period of time during which the light emitted by the chelate complex is suppressed after the electrical field has been removed. For this purpose, viscous substances of certain types, e.g. B. silicon oil, cholesteryl oleyl carbonate or sucrose solutions are added. Obviously, these viscous liquids reduce the rate of diffusion of the dissolved chelate molecules through the solution. As soon as such a molecule has been reduced by taking up a charge from the cathode (which results in fluorescence quenching), it must release this charge again in order to come out of the fluorescence-suppressing state again. If, therefore, the molecule has migrated away from the cathode during the fluorescence quenching time, the recovery phase will take longer after the current has been removed.

There can also be two compounds that fluoresce when excited by UV, placed in the same cell to provide a device capable of multicolor display is. This is achieved by combining a chelate complex of the specified type which is capable of fluorescence quenching with a fluorescent dye whose fluorescence cannot be suppressed is used. Therefore, the fluorescence If one of these components is deleted, only the color of the dye that is not capable of fluorescence extinction remains. During the reversal or removal of the electric field, both compounds fluoresce, leading to the formation of a second color leads. .

It was found that in the display panels according to the invention of the most varied of designs, the fluorescence quenching and the renewed fluorescence is maintained for hours without any noticeable reduction in fluorescence. It is also advantageous that the clear, glossy fluorescence is sufficient Causes brightness, so that the display device is a satisfactory for practical purposes even under normal lighting conditions.

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allows careful consideration. The contrast also proves to be acceptable under these conditions.

The following examples are intended to explain the invention in more detail. example 1

85 mg of the Chelate Tris - / "4,4-, 4-, hereinafter referred to as 1 - trifluoro-1- (2-thienyl) -1 ^ -butan-diono ^ europium der formula

/ "SCH: CHCH: C - COCHiC (CF ₅ ) O _- Z ₅ Eu. 3HgO

were dissolved in 0.1 ml of dimethylformamide (hereinafter abbreviated to DMF). A 1 molar stock solution was obtained from which an aliquot was introduced into a cell of the type shown in FIG. 1 by capillary flow. The used The cell had two glass walls, each with a transparent conductive coating of indium oxide, which was covered with a Line contact was provided. The glass plates were 0.05 mm (0.002 inches) apart separated by dielectric spacers placed around the corners of the glass plates to form a Cavity to accommodate the active luminescent Medium. The entire indexing device was through metal clips held together. After introducing the active medium into the cavity, the cell was with the help of an ÜV lamp with a Irradiated light output of a wavelength of 360 nm. On the side of the cell facing away from the UV light irradiation was the characteristic red fluorescence (612 nm) of the chelate complex used was observed.

2.8 volts (552 volts / cm) were applied to the cell, whereby the quenching of the fluorescence on the cathode conductor was observed. Reversing the polarity led to the return of fluorescence. With complete removal of the electric field

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the dye fluorescence reappeared. It turned out that the electric field cycle was repeatable with no noticeable degradation of the chelate solution.

Example 2

The procedure described in Example 1 was repeated with the exception that that designated 2 below Chelate complex Tris ^ ~ 4,4,4-trifluoro-1- (2-furyl) -1,3-butanediono__7europium the formula

/ ~ 0.GHtGH.CH; C - COCHzC (CT ₅ ) O ^ ₅ -Eu. 3H ₂ O

was used in place of the indicated chelate 1. The medium obtained emitted at a maximum wavelength of about 612 nm.

Example 3

The procedure described in Example 1 was repeated with the exception that that designated 3 below Chelate complex Tris (1-phenyl-1,3-frutandiono) europium of the formula

0 _x

Il Il ⁵

C CH C-0-

-Eu 3

in a solvent consisting of tetrahydrofuran was used. The obtained medium emitted at a maximum Wavelength of about 612 nm.

Example 4

The procedure described in Example 1 was repeated, however with the exception that the one designated 4 below

3 0 9818/1066

- 08 "-

Chelate complex Tris (1-phenyl-1,5-butanediono) terbium of the formula

in a dicmoroethane solvent. The medium obtained emitted at a maximum wavelength of about 54-0 nm.

At s piel 3

The procedure described in Example 1 was repeated with the exception that that designated 5 below Chelate complex Tris (1-phenyl-1,3-butanediono) samarium of the formula

^ "C ₆ H ₅ COCH: C (CH ₅ ) O ^ ₅ Sm

as an active compound together with dichloroethane as a solvent was used. The medium obtained emitted at a maximum wavelength of about 600 nm.

Example 6

This example, like the following examples 7 to 12, shows the influence of the viscosity of the medium.

To 850 mg of the chelate complex labeled 1 (see example 1) and 10 ml of dimethylformamide (DMF) became a 50% strength by weight Solution of cholesteryl oleyl carbonate in DMF added. That The medium obtained was placed in a cell of the type described in Example 1 and exposed to UV radiation, whereupon an electrical potential was applied in the manner indicated. The fluorescence quenching occurred in about 10 milliseconds and / took about 10 seconds for fluorescence to return after removal of the electric field. However, it was If the voltage potential is reversed, the fluorescence was completely restored in about 1/2 second at the same voltage

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manufactured.

Example 7 ■

The procedure described in Example 6 was repeated with the exception that silicone oil was used as the viscous liquid. Practically the same results as in Example 6 were obtained, with the exception that the times indicated were increased by a factor of about 20 % .

Example 8

The procedure described in Example 6 was repeated with the exception that the viscous liquid was a 50 wt .-% solution of sucrose in DMF was used. The results obtained were similar to those reported in Example 6 were obtained.

Examples 9 to 12

The chelate complexes designated 2, 3, 4 and 5 (cf. Examples 2 to 5) were treated according to the procedure described in Example 6. Results were similar to obtained in Example 6.

Example 13

This example, like the following examples 14 and 15, shows the influence of the use of two fluorescent Connections to obtain a multicolored display.

A sufficient amount of monobromofluorescein, Sodium salt added to obtain a 1 molar solution of the salt. When excited by ultraviolet radiation emitted a display cell of the type described in Example 1, which charged with the medium obtained

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a pink fluorescent radiation. Has been to the Irradiated sample applied an electric field of 600 volts / cm, so the pink color changed to blue-purple, which indicated that the chelation mission was suppressed, but not the emission of the dye salt. When the electric field was removed, the pink color returned the emission radiation from the cell.

Example 14

The procedure described in Example 13 was repeated, but with the exception that 1,4-bis (2,4-dianilino) -sym.-triazinoamino are used as the dye whose fluorescence cannot be erased was used. If the cell containing this medium was exposed to UV excitation radiation, so it emitted a red-colored light. An electric field was applied to the cell exposed to the ü * V excitation applied, it emitted blue light, the emission peak of which was about 490 nm.

Example 15

The procedure described in Example 13 was repeated, however, with the exception that eosin was used as the dye whose fluorescence is not erasable. That with UV excitation The emitted light was red and changed into an orange-yellow light emission when an electric field was applied, the peak of which was around 580 nm.

Example 16

This example shows the use of a cell with crossed grids as an electrical conductor »that has a selective connection different parts of the cell to allow the power source.

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Made from so-called "ITesatron" panels (manufactured by PPG Co.) a cross grid cell was produced as an electrical conductor in such a way that strips of the on a glass substrate applied electrically conductive coating were v / eg etched leaving behind conduction lines in such Distance from each other that there were about 20 conductor lines per 2.5 ^ cm. Two flat transparent plates were produced in the manner indicated and in the one described in Pig. 2 illustrated manner arranged so that the conductor strips of a transparent cell wall orthogonal to the conductor strips of the opposite arranged cell wall to lie with formation of an x-y grid came. The distance between the two cell walls was about 50 microns.

A luminescent medium consisting of a 2 molar solution of Tris ^ 4,4,4-trifluoro-1- (2-thienyl) -1 _i 3 "^> butandiono _> _7-europium in The edges of the cavity formed by the cell walls were sealed from the atmosphere by sealing with wax, epoxy resin or silicone rubber.

Electrical connections were then made to each set of strip electrodes using insulated wires low-ohmic contact with silver paint, followed by mechanical "Solidification an epoxy topcoat was applied. The ends of the lead wires were connected to a function generator which made it possible to separate each wire or a pair of wires at a time, or all of the wires at the same time subject to an electrical impulse no greater than 3 volts.

The cell obtained was then with a 14-watt mercury lamp, whose output peak was 360 mn, irradiated. It happened a red fluorescence of the active medium on the upper

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area of the cell opposite the radiation source. The red fluorescence also occurred when the cell appeared the same side on which the viewer was located, was irradiated with UV light. Without applying an electrical The entire display panel fluoresced across its entire field Surface in red light. Was a voltage pulse on the conductor strip of one board and an opposite one If strips of the other plate were applied, the fluorescence of a small part or square was extinguished and the affected area appeared black. In a corresponding manner, 2 opposite conductor strips could each be underneath Electricity can be set with suppression of fluorescence in ^ basic squares, i.e. H. in a square, that of two times two connected conductor strips were formed on each board. In a corresponding manner, different patterns were made generated by energizing various combinations of conductor strips.

If the electric field has been removed or its polarity reversed, it was found that the areas that could be connected returned to their natural fluorescence state within a few milliseconds returned. It was also shown that electronic solid-state systems with the aid of selective switching signals were used to display such a display device and alphanumeric information in real times to display.

Example 17

This example shows the influence of organic salts as charge carriers in media that can be used according to the invention in order to in this way to increase or facilitate the quenching of the fluorescence.

A 1 molar solution of the chelate complex designated 1 was obtained using p-dioxane as a solvent

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ΙΓ

posed. The material obtained was filled into a cell of the type described in Example 1 and exposed to UV radiation, visible fluorescence occurred. However, if a potential was applied as described in Example 1, so there was no quenching of the fluorescence. However, the same chelate solution was used per ml of solution with a few mg of tetra-n-butylammonium perchlorate If an electric field was applied, the fluorescence was quenched.

Example 18

This example shows the one shown in the diagram in FIG. 3 Embodiment.

In a manner similar to how the cross grating described in Example 16 was produced, ^{a pattern was etched onto a so-called 11} Ne satron ¹¹ plate, which, as shown in FIG. 3, enables the numbers 0 to 9 to be displayed. In this standard design, the conductors consisted of seven rods arranged in the form of the number "8" and provided with conductor elements leading to each rod, the electrical connections being provided outside the cell. The complete conductor coating, which formed the anode, consisted of a common known electrode made of so-called ¹ Nesatron ", which was separated from the" Nesatron "plate with the etched" 8 "by 1 micron thick spacers. In the middle of the cell all but the 7-rod electrodes were covered with a layer of photoresist to isolate the electrical leads from the anodes when the cell was filled with an active medium consisting of the chelate complex denoted by 1 and dimethylformamide and exposed to the action of UV radiation. that

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the numbers O to 9 are displayed one after the other and this sequence is repeated became. The signal switching system was designed so that the fluorescence quenching took place on the rods, which did not represent a desired number component, so that the numbers themselves in red fluorescent writing appeared.

In the case of this experimental set-up to isolate the electrical The photoresist material used for the lines was an arylazide-sensitized polyisoprene, which was in the form of a The exposure-curing liquid contained the UV-absorbing dye used, which is 4,4,4-trifluoro-1 (2-thienyl) -1,3-butanedione acted, was resolved. In further experiments it could be shown that correspondingly advantageous results also when using other light-sensitive materials and light-insensitive polymer layers as well as when using other dyes which strongly absorb UV radiation and which are also fluorescent chelates which can be used according to the invention could act, were received.

In further experiments, the indicated display device was used in connection with another separate display image, viewed through the electro-optic cell. at This arrangement a slide projector was used, with the help of which an image on the side facing away from the viewer matted plastic rear projection screen was thrown. The light source of the projector was through a neutral density filter weakened. The display cell was near the projection screen arranged on the side opposite the projector. The target containing the chelate complex was with a 100 watt ultraviolet lamp irradiated, which was arranged on the same side as the viewer was. To this Thus, red fluorescent numbers were generated on the projected images in a form superimposed on these images. Quality Results were obtained when projecting black and white as well as color images.

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Claims (1)

Claims 1. ) A method for the optical display of information, in which a medium, the optical properties of which change due to an electrical potential, - irradiated and an electrical potential is applied to the medium, characterized in that an electrically conductive solution is used as a medium Exposure to UV light fluorescent chelate complex with a rare earth metal, the fluorescence of which is quenched by an electrical potential, is used and this solution is irradiated with UV light. 2. The method according to claim 1, characterized in that the polarity of the applied electrical potential is reversed or switch off the applied electrical potential. 3. Process according to Claims 1 and 2, characterized in that the complex of a metal is used as the chelate complex Rare earths used with a methyl-ß-diketone. M-. Process according to Claims 1 to 3 »characterized in that a chelate complex of the following formula is used: , n + where mean: Q ^{n +} a cation of valence n, where η is an integer from 1 to 6, 309618 / 106-6 2257.398 MT M a rare earth metal with the atomic number 57 to 71 or 89 to 105, R and R ¹ 'monovalent hydrocarbon radicals or monovalent heterocyclic radicals which have not more than 12 carbon atoms and are free from aliphatic unsaturation, and R 'is a radical having the meaning given for R and R "with not more than 10 carbon atoms" which is free of aliphatic unsaturation, or a halogen atom or a cyano radical. 5. Process according to Claims 1 to 4, characterized in that that one uses an electrically conductive solution, which the chelate complex in a concentration of about Contains 0.5 to 2 moles per liter. 6. Process according to Claims 1 to 5 »characterized in that that an electrical potential is applied to the electrically conductive solution, the value of which is at least as great is like the redox potential of the chelate complex. 7 · Electro-optical display device for carrying out the Method according to claims 1 to 6 with a) a cell with two spaced apart transparent, electrically conductive walls which contains a medium whose optical properties change due to an electrical potential, b) a device for applying an electrical potential between the cell walls, c) a radiation source and 309818/1066 d) a device with the help of which the rays of the Be able to ground the radiation source directed into the cell, characterized in that the medium located in the cell consists of an electrically conductive solution Exposure to UV light fluorescent chelate complex with a rare earth metal whose fluorescence is extinguished by an electrical potential, and the radiation source consists of a UV light source. 8. Electro-optical display device according to claim 7, characterized in that the electrically conductive cell walls on the inside a row of parallel, electric have conductive strips which are arranged in such a way that the strips of a wall are orthogonal stand to the strips of the other wall, and the electrical leads for connection to the device for application have an electrical potential. 9 · Electro-optical display device according to claims 7 and 8, characterized in that the device for applying an electrical potential means for reversing the Has polarity of the potential and to switch off the potential. 309818/1066