Abstract: A luminescent layer in an EL device composed of CaGa.sub.2 S.sub.4 :Ce includes a first luminescent layer and a second luminescent layer. The first luminescent layer has an atomic ratio of Ga to Ca being higher than that in the second luminescent layer, and directly disposed on a first insulating layer, whereby delamination can be prevented. The atomic ratio of Ga to Ca in the second luminescent layer is approximately equal to a stoichiometric ratio, so that the threshold voltage of the EL device can be kept low.

Abstract: A carrier-injection type organic electroluminescent device includes, provided on a substrate, a transparent anode electrode, and a hole transport layer containing hole-transporting poly(N-vinylcarbazole) and 2,5-bis(1-naphthyl)-oxadiazole, and 3-(2'-benzothiazoyl)-7-diethylaminocoumarin as a fluorescent material which absorbs light within a predetermined wavelength range and emits light having a longer wavelength. Further included are an electron transport layer containing an electron-transporting tris(8-quinolinolate)aluminum complex, and a cathode electrode. When a voltage is applied between the anode and the cathode, the fluorescent material absorbs light emitted by the recombination of electrons and holes, and emits visible light.

Abstract: A radio-frequency type charged particle accelerator includes a RFQ accelerator and a rear stage RF accelerator both of which are contained in a single evacuated chamber. The RFQ accelerator has quadrupole electrodes positioned along a traveling path of the charged particle and bunches and accelerates a charged particle beam by receiving a radio-frequency power from a radio-frequency power source and resonating. The rear stage RF accelerator is disposed in a rear stage of the RFQ accelerator and accelerates or decelerates the energy of the charged particle beam accelerated by the RFQ accelerator by receiving the radio-frequency power from the radio-frequency power source and resonating. A separating plate is disposed in the single evacuated chamber to separate the RFQ accelerator from the rear stage RF accelerator so that the RFQ accelerator and the rear stage RF accelerator work independently of each other.

Abstract: An electroluminescent device includes first and second layers (6, 12) of light emitting semiconductive conjugated polymers with an electrode arrangement (4, 8, 10, 14) for injecting charge carriers into both light emissive layers to cause light to be emitted therefrom. The first and second light emitting layers are in viewing overlap, and the electrode arrangement includes two sets of electrodes (4, 8, 10, 12) which can be operated independently. The first light emissive layer is arranged to emit radiation of a first wavelength when excited and the second light emissive layer is arranged to emit radiation of a second wavelength when excited. The electroluminescent device can thus be operated to cause either radiation of the first wavelength or radiation of the second wavelength or both to be emitted and viewed.

Abstract: An organic electroluminescent display device (10) includes a plurality of organic layers (16, 18, 20, 22 and 24) disposed between opposing electrodes (14 and 26). The electron injecting layer (24) is characterized by the formula: ##STR1## wherein M is a metal ion, and may be selected from the group consisting of Zn.sup.2+, Mg.sup.2+, Be.sup.2+, Al.sup.3+, and Ga.sup.3+ ; X=2 or 3; and R.sub.1 to R.sub.8 represent functional groups selected from the group consisting of hydrogen, hydrocarbon groups or functional groups such as cyano, halides, haloalkyl, haloalkoxy, alkoxyl, amido, amino, sulfonyl, carbonyl, carbonyloxy, oxycarbonyl, and combinations thereof.

Abstract: The present invention relates to a fluorene-based alternating copolymer to be used as light emitting materials of electroluminescent elements having the following formula (I), and further relates to electroluminescent elements having an anode/luminescent layer/cathode structure, in which the fluorene-based alternating copolymer used as light emitting materials of the luminescent layer, or having a transporting and/or reflection layer added thereto, if necessary, is ##STR1## where R, R', X, Ar and n are defined in the text.

Abstract: A micro-optical resonator type organic electroluminescent device utilizing an organic electroluminescent material high in emission efficiency but broad in emission spectrum width, has a narrow half bandwidth in the emission peak and a superior forward directivity and an excellent monochromaticity in light not separate into components, wherein a micro-optical resonator is formed by a multi-layered mirror and a metal mirror. The optical length of the micro-optical resonator, calculated from the total thickness and the refractive index of a transparent conductive layer and a luminous layer placed between the multi-layered mirror and the metal mirror and also from the light penetration depth into the multi-layered mirror, is 1.5 times the wavelength of a desired light emitted from the device, and the desired light is set on the short wavelength side of the emission spectrum of the electroluminescent material.

Abstract: A transparent thin-film EL display apparatus has a transparent thin-film EL element formed on a glass substrate. A rear substrate consisting of photochromic glass and the glass substrate on which the EL element is formed are disposed facing each other with the EL element located in between. A light-transmitting insulation material is inserted in a space between the two substrates and hermetically sealed. When the display on the EL element becomes hard to see due to light entering from the rear of the display apparatus, the photochromic glass reacts in response to the light and darkens the rear of the EL element, thereby blocking the light.

Abstract: Disclosed is an organic electroluminescence device having a light emitting layer or a light emitting layer and a charge transport layer disposed between a pair of electrodes at least one of which is transparent or semi-transparent, the light emitting layer comprising a conjugated polymer having a repeating unit represented by the general formula (1):--Ar.sub.1 --CH.dbd.CH-- (1)where Ar.sub.1 represents an aromatic hydrocarbon group having 6 to 14 carbon atoms or a nuclear-substituted group in which the aromatic hydrocarbon group is substituted by one or two selected from the group consisting of hydrocarbon groups having 1 to 22 carbon atoms and alkoxy groups having 1 to 22 carbon atoms. According to the present invention, the use of a polymer intermediate of the conjugated polymer or the conjugated polymer soluble to a solvent as a light emitting material, a charge transport material or a buffer layer to an electrode enables an EL device having a large area to be easily made.

Abstract: A thin film electroluminescent element has a color changing layer doped with green luminescent material and red fluorescent material and separated from an electroluminescent layer for generating blue light for converting the blue light to green light and the green light to red light, and the separation results in reduction of trapping center in the electroluminescent layer.

Abstract: An amorphous organic thin-film device comprising an organic thin-film containing a dye molecules represented by the following formula (1) or (2):R-?X-Y!.sub.n (1)R'-?X'-Y!.sub.n (2)wherein R represents an aromatic skeleton, R' represents a heterocyclic aromatic skeleton, X represents a linkage group containing a chemical bond formed by a condensation reaction, X' represents a member selected from the group consisting of a single bond, --O--, --NH--, --NR"CO-- and --CH.sub.2 --, Y represents a dye skeleton with or without a substituent; and n is an integer of 3 or more, in which n members of X, X' and Y may be the same or different.

Abstract: A thin film electroluminescence device and a process for production thereof. This device is characterized in that as a light emitting layer material or charge injection layer material, a polymer film having at least one of a light emitting layer function, a charge transport function and a charge injection function, and having a film thickness of not: more than 0.5 .mu.m is prepared by the vacuum evaporation method and used.

Abstract: An organic electroluminescent display panel having a plurality of emitting portions includes; a substrate on which a plurality of first display electrodes corresponding to emitting portions are formed; electrical insulation ramparts projecting from the substrate for exposing at least portions of the first display electrodes respectively; organic function layers each including at least one organic electroluminescent medium formed on exposed portions of the first display electrodes; second display electrodes formed on the organic function layers; and each electrical insulation rampart having an overhanging portion projecting in a direction parallel to the substrate. The cathodes are patterned automatically without use of the photolithography.

Abstract: An electroluminescent edge emitting device having an improved operational life and electroluminescent efficiency includes a host material composed of at least two Group II elements and at least one element selected from Group VIA. The host material is doped with at least one of the rare earth elements in its 3+ or 2+ oxidation state. In one embodiment of the invention, two Group IIB elements are selected, namely cadmium and zinc. In an alternate embodiment, three Group IIA elements, magnesium, calcium and strontium, are selected as the host material. The Group VIA element is sulfide and/or selenide. The dopant is composed of one, two or three elements selected from the rare earth elements (lanthanides). In an alternate embodiment, the dopants include Mn.sup.2+ and one or two of the lanthanides.

Abstract: The object of the invention is to provide UV light of increased luminous intensity. Layered on one surface of a translucent substrate are a transparent electrode, a first insulating layer, an EL layer, a second insulating layer, and a metal electrode, in that order. A compound of the general formula: Zn.sub.(1-x) Mg.sub.x S is selected as a host material of the EL layer, and Gd or a Gd compound is selected as the luminescence center. The composition ratio x of the compound selected as a host material is selected to be within the range of 0.33.ltoreq.x<1, and preferably within the range of from 0.4-0.8, inclusive. This selection allows the band gap energy of the host material to be higher than the band gap energy of the luminescence center, thus preventing the absorption of the emitted light by the host material and providing UV light of increased luminous intensity.

Abstract: An organic EL device, comprising an anode and a cathode, and at least one organic luminescent medium containing a compound of benzazoles of the formula: ##STR1## wherein: n is an integer of from 3 to 8;Z is O, NR or S; andR and R' are individually hydrogen; alkyl of from 1 to 24 carbon atoms, for example, propyl, t-butyl, heptyl, and the like; aryl or hetero-atom substituted aryl of from 5 to 20 carbon atoms for example, phenyl and naphthyl, furyl, thienyl, pyridyl, quinolinyl and other heterocyclic systems; or halo such as chloro, fluoro; or atoms necessary to complete a fused aromatic ring;B is a linkage unit consisting of alkyl, aryl, substituted alkyl, or subsituted aryl which conjugately or unconjugately connects the multiple benzazoles together.

Abstract: In an organic thin film EL device comprising an anode layer, a cathode layer, and a complex layer including hole injection material and luminescent material, an anode interfacial layer is formed between the anode layer and the complex layer. The anode interfacial layer includes quinacridone derivative.

Abstract: The present invention provides an organic EL element improved in durability. The organic EL element comprises a hole-injecting electrode and an electron-injecting electrode, and at least a film made of a luminous material therebetween, wherein the luminous material is one of a metal complex polymer, an inner complex salt having two or more ligands, and 10-hydroxybenzo [h] quinoline-metal complex.

Abstract: The method and structure for providing a pair of electrical contact terminals on the back side of an electroluminescent (EL) lamp. The EL lamp has a first conductive layer, a layer of EL material, a first insulating layer, a second conductive layer, a second insulating layer and a film of conductive material, all disposed on a transparent substrate, respectively. The film of conductive material extends around the second insulating layer to come in electrical contact with the first conductive layer. This allows an electrical contact terminal to be established on the film of conductive material, rather than directly on the first conductive layer. The other electrical contact terminal is positioned on the second conductive layer. The second insulating layer serves to electrically separate the two contact terminals.

Abstract: An organic electroluminescent device comprises an organic emitting layer and a hole transport layer laminated with each other and arranged between a cathode and an anode, in characterized in that the hole transport layer made of the triphenylbenzene derivative. This hole transport layer has the high heart-resistant property and high conductivity to improve the durability and thus this device emits light at a high luminance and a high efficiency upon application of a low voltage.

Abstract: An electroluminescent device comprising a first electrode, a second electrode and an electroluminescence emission zone, the electroluminescence emission zone being made of a first electroluminescence emission layer, a second electroluminescence emission layer, and a transparent electrode which is interposed between the first electroluminescence emission layer and the second electroluminescence emission layer. At least either the first electrode or the second electrode is a transparent electrode. The first electroluminescence emission layer and the second electroluminescence emission layer emit light by applying a driving voltage to the transparent electrode with both the first electrode and the second electrode connected to a power supply for a reference voltage. In an image sensor using such an electroluminescent device as a light source, the electric field produced by the driving signal of the electroluminescent device does not escape outward, presenting no interfering noise to the image sensor.

Abstract: A thin film electroluminescence device and a process for production thereof. This device is characterized in that as a light emitting layer material or charge injection layer material, a polymer film having at least one of a light emitting layer function, a charge transport function and a charge injection function, and having a film thickness of not more than 0.5 .mu.m is prepared by the vacuum evaporation method and used.

Abstract: An improved dielectric layer of an electroluminescent laminate, and method of preparation are provided. The dielectric layer is formed as a thick layer from a ceramic material to provide:a dielectric strength greater than about 1.0.times.10.sup.6 V/m;a dielectric constant such that the ratio of the dielectric constant of the dielectric material to that of the phosphor layer is greater than about 50:1;a thickness such that the ratio of the thickness of the dielectric layer to that of the phosphor layer is in the range of about 20:1 to 500:1; anda surface adjacent the phosphor layer which is compatible with the phosphor layer and sufficiently smooth that the phosphor layer illuminates generally uniformly at a given excitation voltage.The invention also provides for electrical connection of an electroluminescent laminate to voltage driving circuity with through hole technology. The invention also extends to laser scribing the transparent conductor lines of an electroluminescent laminate.

Abstract: Apparatus according to the invention comprises at least two optical microcavity light emitters. Each one of the at least two light emitters comprises spaced apart reflectors that define a microcavity, and further comprises organic material that is capable of electro-luminescence (e.g., tris (8-hydroxyquinolinol) aluminum, commonly referred to as "Alq"), and means for applying an electric field across the organic material. One of the at least two microcavities has effective optical length L.sub.1, and the other microcavity has effective optical length L.sub.2 .noteq.L.sub.1, with the optical lengths selected such that one of the microcavities emits radiation of a first color (e.g., red), and the other microcavity emits radiation of a second color (e.g., green). In many cases there will be present also a third microcavity that emits radiation of a third color (e.g., blue).

Abstract: An organic electroluminescent device having an organic emitting layer and a hole transport layer laminated with each other and arranged between a cathode and an anode, and the hole transport layer is made of tris-phenothiazinyl-triphenylamine or tris-phenoxazinyl-triphenylamine derivative. The hole transport layer has a high heat-resistant property and high conductivity to improve durability and emits light at a high luminance and a high efficiency upon application of a low voltage.

Abstract: Disclosed is a thin film electroluminescent device of this invention comprising a transparent substrate, a transparent electrode, a fluorescent layer emitting a light when being charged with a certain voltage, a first and second insulating layer being laminated on the top and the bottom of the fluorescent layer to make a dopant be excited and emit a light efficiently, a first light absorbing layer being laminated on the second insulating layer to improve the function of contrast of the device of electroluminescence, a rear electrode formed on the first light absorbing layer at regular intervals, a rear insulating layer being laminated on the rear electrode to prevent the current from leaking from the rear electrode, and a second light absorbing layer being laminated on the rear insulating layer to blacken the etched portion of the first light absorbing layer. A method of fabrication is also disclosed.

Abstract: A multi-color electroluminescent panel comprising common electrodes and a plurality of transparent electrodes, an EL light emitting layer disposed between the common and transparent electrodes and capable of exhibiting a hysteresis in light emission luminance versus applied voltage characteristic, and band-pass color filters provided on the EL light emitting layer for passing therethrough light of a particular color emitted from the EL light emitting layer.

Abstract: There is disclosed an organic electroluminescent device, comprising a multilayered structure of an organic film for electron injection, and an organic film for hole injection, at least one of which consists of a plurality of layers, and an organic film serving as a light-emitting layer interposed therebetween, a first electrode for electron injection formed on the side of the organic film for electron injection of the multilayered structure, and a second electrode for hole injection formed on the side of the organic film for hole injection of the multilayered structure, wherein a barrier height against electron injection at each interface between layers present from the first electrode to the organic film serving as the light-emitting layer is not more than 0.6 eV, and a barrier height against hole injection at each interface between layers present from the second electrode to the organic film serving as the light-emitting layer is not more than 0.6 eV.

Abstract: Disclosed herein is a method for manufacturing edge emission type EL device arrays. A substrate carrying individually formed EL device arrays is coated with a transparent film. The film is etched to form terminals through exposure of the edges of block terminals and to make contact holes reaching an upper electrode layer of the EL devices. The contact holes are then covered with a conductive layer that is etched to form common electrodes conductive to predetermined edge emission type EL devices within each block.

Abstract: The present invention relates to a multilayer phosphor layer system for an electroluminescent display. The phosphor layer according to the invention is comprised of several superimposed host matrix material layers (7) and interposed activator-containing doping layers (9, 10). The activator-containing doping layers (9, 10) are extremely thin, whereby disturbance to crystal growth of the host matrix material at the doping layer (9, 10) is avoided. The activator-containing doping layer (9, 10) can be comprised of an actual activator layer (10) and a matching layer (9) adapted between said host matrix material layer (7) and said actual activator layer (10), whereby said matching layer (9) improves the matching between said host matrix material layer (7) and said actual activator layer (10). By virtue of the layered structure, it is possible to use such host matrix/activator material pairs that otherwise would be useless due to their poor efficiency or weak light emission.

Abstract: Disclosed is an electroluminescent element comprising an anode, a cathode and, disposed therebetween, an organic luminescent layer comprising a mixture of a fluorescent luminescent agent, at least one hole moving and donating agent capable of moving holes and donating the same to the luminescent agent and at least one electron moving and donating agent capable of moving electrons and donating the same to the luminescent agent. In the element, the components of the luminescent layer have specific oxidation potential and reduction potential relationships. The element emits light in response to electrical signals. The element exhibits high luminescence efficiency and brightness even at low voltages, and it can efficiently be produced at low cost.

Abstract: A multi-color electroluminescent panel comprising common electrodes and a plurality of transparent electrodes, an EL light emitting layer disposed between the common and transparent electrodes and capable of exhibiting a hysteresis in light emission luminance versus applied voltage characteristic, and band-pass color filters provided on the EL light emitting layer for passing therethrough light of a particular color emitted from the EL light emitting layer.

Abstract: An electroluminescent panel and a method of manufacturing the same which comprises: forming a roll of luminous base film which includes a luminous layer made of phosphors embedded in an insulating material, the luminous layer being laminated upon a conductive film; forming a roll of a transparent conductive film; passing the luminous base film and the transparent conductive film between a pair of rollers while sandwiching a power supply bus bar made of a metal film therebetween, to thereby form the luminous film, the transparent conductive film and the power supply bus bar into an integrated body by means of pressurized heating; cutting the integrated body into at least one piece having a predetermined length; and mounting a terminal to the at least one piece packaging the at least one piece with a moisture proof film.

Abstract: Disclosed is an electroluminescent device including a substrate and an electroluminescent film on the substrate wherein the electroluminescent film is composed of a II-VI group compound semiconductor matrix and an electroluminescent center element; the improvement being present in that the electroluminescent film has a crystal structure of a hexagonal system, and contains the electroluminescent center element in a concentration (Ci) of 0.5 to 4 at. % within a thickness of 0.2 micrometer from the side of the substrate and in a concentration (Cr) of 0.15 to 0.7 at. % at the residual portion, and Ci is larger than Cr, and the process for preparing the same.

Abstract: An electroluminescence device containing a first organic compound having positive-hole-transporting and luminous properties, such as a triphenyl amine compound, a stilbene derivative or a pyrazoline derivative, and a second organic compound having electron-transporting property, such as an oxadiazole derivative, in its luminescence layer interposed between a pair of electrodes.

Abstract: An electroluminesence device comprising an organic compound having positive-hole-transporting property and a fluorescent organic compound having electron-transporting property in its luminescence layer interposed between a pair of electrodes. When the electroluminescence device comprises a cyclopentadiene derivative having formula (I) as the fluorescent organic compound, the device can emit blue light which has not been attained so far: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, which may have a substituent, an alicyclic group having 5 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, which may have a substituent, a halogen, an acyl group, a hydroxyl group, an aryloxy group, an aryl group which may have a substituent, an allyl group, or an aldehyde group.

Abstract: A thin-film EL display having a high-contrast ratio comprising a transparent ceramic substrate. A background electrode is formed on the lower surface of the ceramic substrate. A photochromism layer is formed on the upper surface of the ceramic substrate. The photochromism layer is black-colored when exposed to a required wavelength of light of 3,500 .ANG. to 5,100 .ANG.. Therefore, it is possible to avoid decrease in the contrast of the display device which may be caused by external light or light emitted from the fluorescent layer itself.

Abstract: Disclosed herein is an electroluminescent element which is constructed such that a fluorescent substance layer and a hole transport layer, both made of organic compounds and laminated on top of the other, are interposed between a cathode and an anode. The fluorescent substance layer is a thin film containing a bisstyryl derivative. It emits blue light efficiently at a high luminance upon application of a low voltage.

Abstract: A memory effect, monochromatic display of the photoconductor-electroluminescent type, includes on a substrate an electroluminescent layer and a photoconductor layer in stacked relation. The stack is interposed between two electrode systems used for exciting the electroluminescent layer, the latter having an emission spectrum overlapping the sensitivity spectrum of the photoconductor material. An optical filter is located between the electroluminescent layer and the display observer and permits the passage of that part of emission spectrum of the electroluminescent layer most useful for display purposes while blocking a region of the emission spectrum of the ambient illumination, the sensitivity spectrum of the photoconductor layer then being essentially contained in said region.

Abstract: A photoconductive-electroluminescent, memory effect polychromatic display defining a first and second inverted structure. The first structure incorporates a first transparent substrate equipped with a first electroluminescent layer El.sub.1 placed between a first and a second electrode system, which are connected to a first electrical source for exciting certain zones of layer El.sub.1. The second inverted structure incorporates a second substrate equipped with a second electroluminescent layer El.sub.2 and a photoconductive layer stacked on one another. These two layers are inserted between a third and a fourth electrode system which are connected to a second electrical source for exciting certain zones of the layer El.sub.2. The electroluminescent layer El.sub.1 has a monochromatic or dichromatic emission spectrum and the electroluminescent layer El.sub.2 has a monochromatic emission spectrum essentially complementary to layer El.sub.1.

Abstract: A photoelectron beam converting device including a semiconductor substrate having a p-n junction formed between an n-type region and a p-type region and an opening portion formed on the side of the semiconductor substrate. An electron beam is generated by a light which enters from the opening portion and by a reverse voltage to be applied to the p-n junction.

Abstract: An electroluminescent device is disclosed comprised of, in sequence, an anode, an organic hole transporting zone, an organic electron transporting zone, and a cathode. The cathode is comprised of a layer of a plurality of metals other than alkali metals, at least one of said metals having a work function of less than 4 eV.

Abstract: An electroluminescent display device uses a photoconductive material which is of hydrogenrated and carbonated amorphous silicon of formula a-Si.sub.x C.sub.1-x ; with 1-x preferably between 0.05 and 0.50 and which has application to display functions.

Abstract: An electroluminescent display with a memory effect. The display includes an electroluminescent layer and a photoconductive layer, both of which are thin films of approximately 1 micron. The two layers are placed between two systems of electrodes which are connected to a power source. Thin dielectric film may also be part of the assembly.

Abstract: A multicolor luminescent article comprises a layer of a first luminescent semiconductor having a discontinuous layer, pattern or image comprised of a second luminescent semiconductor on at least one surface thereof.

Abstract: An electroluminescent device is disclosed comprising in sequence, an anode, an organic hole injecting and transporting zone, an organic electron injecting and transporting zone, and a cathode. The organic hole injecting and transporting zone is comprised of a layer in contact with the anode containing a hole injecting porphyrinic compound and a layer containing a hole transporting aromatic tertiary amine interposed between the hole injecting layer and the electron injecting and transporting zone.

Abstract: The present invention relates to an electroluminescent display device with polychromatic emissions which comprises one photo electroluminescent layer containing a composition of Na.sub.0.5 Tb.sub.0.25 Eu.sub.0.25 WO.sub.4 which is combined with an existent fluorescent layer, the thickness of which is one-third that of the fluorescent layer.

Abstract: A thin-film electroluminescent panel which has a light sink layer deposited immediately behind the phosphor layer thereof is modified to have a light emission enhancing dielectric layer deposited between the phosphor layer and the light sink layer. The light emission enhancing dielectricphosphor interface provides for injecting hot electrons for impact-exciting the luminescent centers in the phosphor to enable the panel to generate light when the front electrode of the panel is positive in potential. Moreover, the light emission enhancing dielectric layer is formed of a material having the same index of refraction as the phosphor layer so that it will pass the incident ambient light and the rearwardly directed light generated in the phosphor layer without reflection into the light sink layer wherein it is trapped by internal reflection and absorbed.

Abstract: A photoelectrochemical cell (10) is disclosed which has a semiconductor substrate (11) formed of a solid solution of three metal and non-metal elements, with two like elements varying in concentration with depth from an exposed surface (13) of the substrate (11). The band gap energies between the valence and conduction bands varies with the concentration of the two elements from the surface, with the band gap energies being in a proper range to provide emitted light in response to light or electrical stimulation. An electrolyte (14) is maintained in contact with the exposed surface and a counterelectrode (15) is immersed in the electrolyte such that a voltage applied between a counterelectrode (15) and the substrate (11) will vary the color of light emitted from the exposed surface (13) in response to incident light or by stimulation from the electrical current passing through the substrate.

Abstract: A dual-color photographic sensitometer for exposing a piece of test film to a known amount of light of a selectable one of two different colors. The multiple-step density gradient of the sensitometer is uniformly illuminated along its entire length by an electroluminescent lamp comprising a plurality of phosphor segments of varying widths which are electrically connected to form two sets, with each of the segments in each set adapted upon excitation to emit a single color light. The width of each segment of a set is determined in accordance with its distance from the multiple-step density gradient so that the multiple-step density gradient is illuminated substantially uniformly by each segment set.