Abstract: A plasma display device with a phosphor screen, comprising a phosphor composition of an UV-phosphor furnished with a coating which includes one or more catena-polyphosphates of metals of the group formed by the alkaline earth metals, zinc, cadmium and manganese, can effectively be used to counteract degradation of the phosphor by UV-excitation.

Abstract: A low-pressure mercury discharge lamp is provided with a discharge vessel (1) which encloses a discharge space (2) in a gastight manner and in which a filling including mercury is accommodated. The lamp is provided with means (3a, 3b) for maintaining an electric discharge in the discharge space. The discharge vessel is provided with a luminescent layer (5). The lamp generates light during operation with a spectrum which is substantially composed of radiation in a first wavelength region from 590 to 630 nm, a second wavelength region from 520 to 565 nm, and in a third wavelength region from 430 to 490 nm. The radiation in the wavelength interval from 590 to 600 nm accounts for at least 50% of the power of the radiation in the entire first wavelength region. A preferred embodiment of the lamp includes a luminescent material that complies with the formula M1.sub.x M2.sub.(1-x-y) BO.sub.3 :Eu.sup.3+.sub.

Abstract: An image-forming apparatus has a rear plate including electron-emitting devices formed thereon, a face plate including a fluorescent film formed thereon and being disposed to face the rear plate, flat plate spacers disposed between the rear plate and the face plate, and an outer frame surrounding peripheral edges of the rear plate and the face plate. Electrons emitted from the electron-emitting devices are irradiated to the fluorescent film to thereby display an image under condition where an inner space of a container constructed by the rear plate, the face plate and the outer frame is evacuated through a vent tube into a depressurized state. The vent tube is attached to a side of the outer frame that is positioned across an imaginary extension of the flat-plate spacer in the longitudinal direction thereof, or to the face plate or the rear plate in the vicinity of that side of the outer frame.

Abstract: A highly safe fluorescent lamp is disclosed, in a mixed layer having couplings of phosphors and a metal oxide such as yttrium oxide is formed on the inner surface of a glass bulb. The couplings of the mixed layer strongly couples the grains arranged in crosslinked state between the phosphor grains of the phosphor material. A first thin film of the metal oxide is formed between the glass bulb and the mixed layer. A second thin film of the same metal oxide is formed on the inner surface of the mixed layer nearer to the bulb center. The amount of mercury sealed in the glass bulb thus is reduced, thereby minimizing the mercury consumption which has so far been the problem against environmental protection.

Abstract: A mercury-free ultraviolet (UV) discharge source includes an elongated envelope having a diameter in a preferred range from approximately 2 to 3 cm, containing a rare gas fill (xenon or krypton, including mixtures of these with other rare gases) at a pressure in a range from approximately 10 millitorr to approximately 200 millitorr and a power supply for ionizing the rare gas fill and generating a discharge current in a range from approximately 100 to approximately 500 milliamperes (mA). The UV discharge source has an efficiency and output comparable to existing mercury-based low-pressure discharge sources and is intended for use with a suitable phosphor capable of converting the UV radiation to visible light in a fluorescent lamp.

Abstract: An afterglow lamp has a light emitting section for converting electric energy to optical energy. A fluorescent layer is excited to emit-light by the light emitting section and is represented by the general formula (M.sub.1-p-q, Eu.sub.p Q.sub.q)O.multidot.n(Al.sub.1-m B.sub.m).sub.2 O.sub.3 .multidot.kP .sub.2 O.sub.5 .multidot..alpha.X. The values of p, q, n, m, k, .alpha. and .alpha./n are in the ranges 0.0001.ltoreq.p.ltoreq.0.5, 0.0001.ltoreq.q.ltoreq.0.5, 0.5.ltoreq.n.ltoreq.3.0, O.ltoreq.m.ltoreq.0.5, O.ltoreq.k.ltoreq.0.2, O.ltoreq..alpha..ltoreq.0.5, and O.ltoreq..alpha./n.ltoreq.0.4. M is at least one selected from a group of divalent metals including Mg; Q is a coactivator and at least one selected from a group including Mn, Zr, Nb, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; and X is at least one selected from halogen elements.

Abstract: A fluorescent lamp comprises a plurality of metameric blends of lamp phosphors for converting ultraviolet radiation to visible illumination.

Abstract: A fluorescent lamp has a coating on the interior surface of the glass envelope comprising an alkaline earth metal halophosphate phosphor and a quad-phosphor blend wherein the combination of phosphors result in a predetermined color point from about 2700 to about 4200 K on or near the Planckian locus where the alkaline earth metal halophosphate phosphor comprises a blend of halophosphate phosphors having a color temperature substantially matching the color temperature of the quad-blend which includes an europium activated aluminate as a phosphor component.

Abstract: A fluorescent lamp having no more than one layer inside the glass envelope, the one layer being a phosphor-containing layer which is at least 20 weight percent alumina. The phosphor-containing layer preferably comprises a rare earth triphosphor blend.

Abstract: A lighting unit includes a discharge vessel having a wall provided with a first luminescent layer, a gas fill consisting essentially of neon at a pressure less than 30 mbar, and a means for providing a constant DC current for exciting the fill in the discharge vessel to emit UV light for exciting the luminescent layer. DC operation offers substantially higher luminous flux over AC operation. The lighting unit may further include a housing having a reflective surface, a second luminescent layer, and a filter incorporated within the discharge vessel.

Abstract: There is provided a method for formulating a three-wavelength fluorescent material 2 in which a blue fluorescent material B2 has a half-width value of 25 to 40 nm, a green fluorescent material has a particle diameter of 4.0 to 8.0 .mu.m, and the blue florescent material B2/green fluorescent material G2/red fluorescent material R1 mixing ratio is 29.2:42.0:28.8. The present invention makes it possible to improve the brightness of a three-wavelength florescent lamp 1 using this three-wavelength fluorescent material 2 by substantially 13% and the flux of light thereof by substantially 4%, thus realizing a brighter three-wavelength fluorescent lamp.

Abstract: A phosphor film structure comprising a substrate and a phosphor film formed on the substrate, wherein the phosphor film comprises ultrafine phosphor particles having an average diameter of 200 nm or less, and obtained by heating a phosphor material to vaporize and rapidly quenching to solidify, and a haze of the phosphor film to a luminous flux of 380-760 nm in wavelength is 50% or less.

Abstract: A fluorescent lamp includes a light-transmitting envelope, means for generating a discharge within envelope, a discharge sustaining fill contained in envelope for emitting ultraviolet rays during the lamp operation and a phosphor layer coated on an inner surface of envelope. The phosphor layer converts the ultraviolet rays into visible light and ultraviolet radiation within a wavelength range of 320 nm to 410 nm so as to have radiant flux ratio of ultraviolet radiation of 5 to 50 percent of the entire radiant flux of the lamp.

Abstract: A fluorescent lamp and a color liquid crystal display device, into which the fluorescent lamp is incorporated, use three-wavelength light emitting phosphers not to cause any interference fringe so as to eliminate color shadings from the display screen of said device. A phospher film consisting of a combination of the phosphers having their peak light emitting wavelengths at red, green and blue three-wavelength areas or ranges is formed on inner faces of a bulb of said fluorescent lamp, a half value width at the peak light emitting wavelength of each phospher i set to be in a range of 30 nm-100 nm, and a phospher defined by a general formula M.sub.3 (PO.sub.4).sub.2 :Sn, Mn (wherein M is at least one of Sr, Mg, Ba, Ca, Zn and Ga) is used as the red light emitting one. Fringes caused by the interference of light penetrating each optical component of the color liquid crystal display device with light reflected by front or boundary faces of these optical components can be thus prevented.

Abstract: A low pressure mercury vapor discharge lamp is provided, having a non-straight glass envelope and a plurality of rare earth phosphor layers coated inside the glass envelope. The lamp is made by coating a plurality of rare earth phosphor layers inside a straight glass tube. The tube is then formed into a non-straight configuration, each layer being sufficiently thin so that the phosphor coating does not flake off in sections where the tube is bent around a radius of curvature. A plurality of thin rare earth phosphor layers will not flake off in the bent section whereas a single thick rare earth phosphor layer will flake off. The invention is particularly useful in the manufacture of helical compact fluorescent lamps.

Abstract: A fluorescent lamp comprises at least one layer of a quad-phosphor blend for emitting visible illumination having a white color. The quad-phosphor blend comprising a first and second green emitting phosphor component with each green emitting phosphor component having different visible emission spectrum principally in the 520 to 560 nm wavelength range. A third blue emitting phosphor component has an emission spectrum principally in the 440 to 470 nm wavelength range. A fourth red emitting phosphor component has an emission spectrum principally in the 590 to 620 nm wavelength range. The first green emitting phosphor component is a alkaline earth metal activated phosphor and the second green emitting phosphor is a rare earth activated phosphor wherein the relative proportions of the phosphor components are such that an enhanced color rendering index is produced as compared to tri-component blends formed from three of the phosphor components.

Abstract: A lighting unit according to the invention comprises an electrodeless low-pressure discharge lamp and a high-frequency supply. The electrodeless low-pressure discharge lamp is provided with a discharge vessel which is closed in a gastight manner, comprises an ionizable filling, and has an enveloping portion and a recessed portion surrounded by the enveloping portion, which enveloping and recessed portions of the discharge vessel each support a luminescent layer. The electrodeless low-pressure discharge lamp is in addition provided with a coil which is arranged in the recessed portion of the discharge vessel and which is electrically connected to the supply. The conversion efficiency of the luminescent layer on the recessed portion is relatively high compared with that of the luminescent layer on the enveloping portion. This measure renders possible a lower temperature of the core.

Abstract: A discharge lamp and an illumination instrument for general illumination which is able to reproduce a preferable skin color of Japanese women by an illumination light, in relation to the skin test color of Japanese women, which is important for general illumination, and is characterized in that, when the color point of the skin test color No. 15 for calculating the color rendering index according to JIS Z 8726-1990 under the light of the discharge lamp is converted to the color point under the standard illuminant CIE D65 using the CIE chromatic adaptation equation, the color point is in the elliptical region of which the major axis is 0.0068, the minor axis is 0.0037 and the inclination from the u' axis is 40.degree., centering around (u',v')=(0.2425, 0.4895) on the CIE 1976 u'v' chromaticity diagram.

Abstract: A low-pressure mercury discharge lamp with a lamp vessel having a first lamp vessel portion (La1) with a first electrode (E11) and a first luminescent layer which radiates white light of a first color temperature during lamp operation and a second lamp vessel portion (La2) with a second electrode (E12) and with a second luminescent layer which radiates white light of a second colour temperature different from the first during lamp operation. The first lamp vessel portion and the second lamp vessel portion are interconnected by a connection which allows a filling of mercury and a rare gas in both portions to pass and together enclose a discharge space. The discharge space contains only one further electrode (E13) for both the first and second lamp vessel portions.

Abstract: A plurality of filaments are stretched in parallel on a rear plate, and an insulating plate is provided so as to cover the filaments. In the insulating plate, a plurality of through-holes are formed along the longitudinal direction of the respective filaments for exposing parts thereof. Each through-hole and phosphor layers, which are provided on the insulating layer adjacent to the through-hole, constitute one unit picture element. The respective phosphor layers in the respective picture element are installed in a plurality of cavities formed in a rib provided on a lower surface of the insulating plate, whereby separated from the neighboring phosphor layers. The respective cavities function as a discharge room, with a light-transmissive front plate, formed on the rib, as a lid and a portion of the insulating plate corresponding to the phosphor layer as a bottom. The respective discharge rooms overlap the through-hole at one end in the longitudinal direction thereof.

Abstract: A phosphor blend and a low pressure discharge lamp utilizing such a phosphor blend is provided having a lamp envelope 3 having an inner surface 15, means 5,6,7,9,13 within the lamp envelope for generating ultraviolet radiation; and a layer 17 of a luminescent material adjacent the inner surface of the lamp envelope for generating visible light when impinged by the ultraviolet radiation. The luminescent material is a phosphor blend consisting essentially of (1) a first luminescent material comprising gadolinium and magnesium pentaborate, preferably activated by cerium, manganese, and terbium; (2) a second luminescent zinc silicate material; (3) a third luminescent alkaline earth halophosphate material; and (4) a fourth luminescent alkaline earth metal halophosphate material, the components of said blend being combined in proportions which are selected depending on the lamp color desired whereby a full spectrum in visible and CRI values of at least 82 are provided.

Abstract: A luminescent material for a mercury discharge lamp comprises a phosphor material including phosphor particles for emitting a luminous flux upon excitation by ultraviolet radiation at 254 nm and a protective layer continuously formed on the phosphor particle with at least one metal oxide selected from the group consisting of MgO, Y.sub.2 O.sub.3, La.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Gd.sub.2 O.sub.3, Dy.sub.2 O.sub.3, Ho.sub.2 O.sub.3, Er.sub.2 O.sub.3, Yb.sub.2 O.sub.3, Lu.sub.2 O.sub.3, CaO, ZrO.sub.2, SrO, BaO, .alpha.-Al.sub.2 O.sub.3 and BeO. A mercury discharge lamp has a luminescent layer coated with the luminescent material on the wall of the light transmissive bulb thereof.

Abstract: A fluorescent lamp having multiple discrete zones with different levels of radiation intensity along its length has a tube with a fluorescent coating on the interior of the tube adapted to produce ultraviolet radiation of substantially uniform intensity. A reflective coating is provided along a finite length of the tube adjacent one end thereof and about only a portion of the circumference thereof to provide an increased intensity of radiation emanating from the uncoated portion of the periphery of the lamp in the finite portion due to reflection of radiation from the reflective coating. This lamp is especially useful in an array for a tanning chamber to provide a higher intensity of ultraviolet radiation in the facial area.

Abstract: A fluorescent lamp having multiple zones with different ultraviolet radiation characteristics along its length has a tube with a first fluorescent coating for producing ultraviolet radiation of substantially uniform intensity extending over a first finite length of the tube adjacent one end. A second fluorescent coating extending over a second finite length of the tube adjacent its other end thereof produces ultraviolet radiation of a substantially uniform intensity and having radiation characteristics which are different from those produced in the first finite length. Generally, the UVB intensity and UVB/UVA ratio will be increased. This lamp is ideally suited for use in tanning chambers to provide uniform tanning by providing a higher intensity and a higher UVB/UVA ratio for radiation in the area of the head.

Abstract: A color film image reader for obtaining an image signal from a color film, comprising a light source for irradiating the color film with light; a color CCD for producing blue, green and red image signals from the light received from the color film; and means for adjusting the level of each of the image signals obtained by the color CCD. The light source comprises a 3-band type fluorescent lamp, and the relative emission powers thereof regarding blue, green and red light are approximately at a ratio of 10:4:1, wherein the molar weight ratios of its blue, green and red fluorescent materials satisfy the functions that (molar weight ratio of blue fluorescent material.quantum efficiency of blue fluorescent material):(molar weight ratio of green fluorescent material.quantum efficiency of green fluorescent material).(molar weight ratio of red fluorescent material.quantum efficiency of red fluorescent material).apprxeq.10:4:1. The glue fluorescent material is composed of BaM.sub.g2 Al.sub.16 O.sub.

Abstract: A fluorescent lamp produces light having color coordinates within an ellipse (A) about 22 standard deviation of color matching around the color coordinates (b)x=0.344 y=0.302. The luminescent layer of the lamp includes a mixture of: magnesium fluorogermanate activated by manganese as red emitter; calcium halophosphate as white emitter; and a blue emitter preferably strontium pyrophosphate activated by divalent tin. The layer may alternatively be a mixture of red emitting magnesium fluorogermanate and blue emitting barium titanium pyrophosphate. Other blue emitters are also described.

Abstract: The invention provides a fluorescent lamp for plant growth capable of controlling morphology in terms of grass height, area and shape of leaves and so forth, approximating those obtained under natural daylight, while effectively promoting photosynthesis of the plant. The fluorescent lamp has a glass tube and a fluorescent layer formed on the inner surface of the tube and composed of four fluorescent components having light emission peaks in the bands of 440 to 460 nm, 540 to 560 nm, 600 to 620 nm and 700 to 800 nm, respectively, said fluorescent layer having the PF ratio ranging from 0.8 to 1.2 in terms of the ratio between the photon flux PF contained in the wavelength band of 600 to 700 nm to that in the wavelength zone of 700 to 800 nm.

Abstract: A low-pressure mercury discharge lamp with a very good color rendering and with a color point (x.sub.L, y.sub.I) on or close to the Planckian locus, includes a gastight, radiation-transmitting envelope which contains mercury and rare gas, and a luminescent layer includinga first luminescent material activated by bivalent europium and having an emission band whose maximum lies between 470 nm and 500 nm and whose half-value width is at most 90 nm,a second luminescent material activated by bivalent manganese and having at least an emission band mainly in the red region of the visible spectrum,a third luminescent material with a band emission whose maximum lies between 430 nm and 490 nm,a fourth luminescent material with emission mainly between 520 nm and 565 nm, anda fifth luminescent material with emission mainly between 590 nm and 630 nm.

Abstract: The invention relates to a low-pressure mercury discharge lamp with a very good color rendering and with a color point (x.sub.L, y.sub.L on or adjacent the Planckian locus, provided with a gastight, radiation-transmitting envelope which contains mercury and rare gas, and provided with a luminescent layer which comprisesa first luminescent material activated by bivalent europium having an emission mainly in the blue region of the visible portion of the spectrum,a second luminescent material activated by bivalent manganese and having at least an emission band mainly in the red region of the visible spectrum anda third luminescent material having an emission mainly in the yellow region of the visible spectrum.According to the invention, the third luminescent material is defined by the formulaSr.sub.(2-x-y) M.sub.x SiO.sub.4 :Eu.sup.+2.sub.y,in which 0,0005.ltoreq.y.ltoreq.0,05, M being barium and/or calcium and 0,01.ltoreq.x.ltoreq.0,1.

Abstract: A lamp for producing a spectral distribution which is substantially identical to daylight color temperature. The lamp contains a filament which, when excited by electrical energy, emits radiant energy at least within the visible spectrum with wavelengths from about 400 to about 700 nanometers, a reflector body with a surface to intercept and reflect the visible spectrum radiant energy which is positioned within the reflector so that at least 50 percent of the visible spectrum radiant energy is directed towards the reflector surface, and a coating on the surface of the reflector body from which the reflected radiance of each wavelength of visible spectrum radiant energy directed towards the reflector surface when combined with the visible spectrum radiant energy not directed towards the reflector surface produces a total light output in substantial accordance with a specified formula.

Abstract: A gas discharge tube that is capable of lighting in different colors. The gas discharge tube, which may contain neon and mercury vapor, and which has its inner surface coated with a photoluminescent layer, is energized with a pulse current. The resultant color of the light emitted from the gas discharge tube depends in part on the frequency of the pulse current.

Abstract: A low pressure mercury vapor discharge lamp is operated at a power more than 550 W/m.sup.2. The lamp has a first layer comprising first grains coated on the inner surface of the tube thereof and a second layer comprising second grains coated on the first layer. The second grains are more positive in contact electrification than the first grains. The lamp reduces an early decrease in luminous flux.

Abstract: Yttrium-containing phosphors can be stabilized for use in an aqueous slurry containing a binder, which slurry can be used for coating fluorescent lamps by treating with ammonium dihydrogen phosphate and ammonium hydrogen difluoride to inactivate free yttrium ions. The resulting aqueous slurry is stable and provides coated fluorescent lamps having uniform coatings that are bright and long lasting.

Abstract: A blue-emitting phosphor of europium-activated barium magnesium aluminate is used in a high color rendering three-band type fluorescent lamp, in which the particle size distribution is uniform to obtain excellent phosphor layer. A fluorescent lamp employing the blue-emitting phosphor mixed with red and green-emitting phosphors has a uniform emission luminance distribution and increased luminous flux intensity. The employed blue phosphor is expressed:Ba.sub.a Mg.sub.b Al.sub.c La.sub.x O.sub.a+b+3(c+x)/2 :Eu.sub.dwhere 0.1.ltoreq.a.ltoreq.2.4, 0.1.ltoreq.b.ltoreq.5, 8.ltoreq.c.ltoreq.64, 0.001.ltoreq.x.ltoreq.0.2, and 0.1.ltoreq.d.ltoreq.4.

Abstract: A fluorescent lamp providing improved maintenance and brightness includes an alkaline earth halophosphate (Cool-White) phosphor, e.g. a calcium halophosphate phosphor, having a continuous protective bilayer coating of alumina surrounding silica surrounding the phosphor particles. The lamp may be a high color rendition fluorescent lamp in which a first layer of alkaline earth halophosphate phosphor coats an inner surface of the lamp envelope, and a second layer of phosphor overlies the first layer of phosphor. The second layer of phosphor is a mixture of red, blue and green emitting phosphors, at least one of these being a zinc silicate phosphor. Each of the alkaline earth halophosphate and zinc silicate phosphors have a bilayer coating in which a coating of alumina surrounds a coating of silica which surrounds the phosphor.

Abstract: A fluorescent lamp characterized in that the charging tendency of a phosphor used is positioned more negative side than that of metal oxides each having a metal ion electronegativity X.sub.i of 7.0 but more positive side than that of metal oxides each having a metal ion electronegativity X.sub.i of 11.8, that particles of the phosphor are charged positive and smaller than 3.0 .mu.C per gram when they are in contact with soda lime glass beads each having a particle size of 200-500 .mu.m, or that they are charged negative and larger than -0.5 .mu.C per gram when they are in contact with reduced iron powder having a particle size of 44-74 .mu.m.

Abstract: Yttrium-containing phosphors can be stabilized for use in an aqueous slurry containing a binder, which slurry can be used for coating fluorescent lamps by treating with ammonium dihydrogen phosphate and ammonium hydrogen difluoride to inactivate free yttrium ions. The resulting aqueous slurry is stable and provides coated fluorescent lamps having uniform coatings that are bright and long lasting.

Abstract: A color sequential illumination system, such as, for example, a backlighting system for a liquid crystal display (LCD), comprises lamps for emitting blue, red and green light. The red and green light is provided by lamps including fluorescent dyes having optical decay times similar to a phosphor material used to provide the blue light. In this manner, the blue, red and green emissions can be fully synchronized with electrical signals used to energise the lamps, enhancing color range and color quality. Furthermore, if the fluorescent dyes are carried in plastics materials, then trapping and concentration of the light generated may also be achieved, providing enhanced brightness for the LCD for a given power input.

Abstract: A bivalent europium-activated alkaline earth haloborate phosphor which contains lithium as coactivator, a process for its production, and an ultraviolet ray excited fluorescent tube such as a fluorescent lamp having a fluorescent layer containing such a phosphor as the blue-emitting component.

Abstract: Low-pressure mercury vapor discharge lamp for suntanning purposes comprising a tubular discharge vessel which is provided on the inside with a first luminescent layer comprising a first luminescent material which emits mainly UVA and with a second luminescent layer which comprises a second luminescent material which emits mainly UVA, the two luminescent materials also showing mutually different UVB emission contents. At least one of the two luminescent layers extends over only part of the circular circumference of the discharge vessel with the object of obtaining different quantities of UVB radiation emission in different transverse directions of the lamp. The luminescent material having the lowest UVB emission is disposed on the wall of the discharge vessel and absorbs a portion of the UVB emission from the other luminescent material which is disposed closest to the discharge and has the higher UVB emission.

Abstract: A low-pressure mercury vapor fluorescent lamp has a luminescent coating including a small quantity of a fine grain inactive material such as a calcium, strontium or barium chloroapatite, which inactive material has a surplus of a metallic cation giving the coating a net positive charge to deter absorption of mercury ions and prolong the life of the lamp.

Abstract: Low-pressure mercury vapor discharge lamp with an emission spectrum according to a spectral energy distribution comprising the wavelength ranges 380-490 nm, 490-590 nm, and 590-700 nm, within which wavelength ranges mutually equal or substantially equal quantities of energy are emitted with a tolerance of 25% for the mutual ratios of equal energy of 1:1:1.

Abstract: A gas discharge tube that is capable of lighting in different colors. The gas discharge tube, which may contain neon and mercury vapor, and which has its inner surface coated with a photoluminescent layer, is energized with a pulse current. The resultant color of the light emitted from the gas discharge tube depends on the combination of the pulse shapes and duty factors constituting the pulse current.

Abstract: A phosphor blend for a fluorescent lamp having four rare earth phosphors, each of which emits a narrow band of visible light energy in the visible spectrum. The color of the light produced by three of the phosphors is red, blue and green. The fourth phosphor producing light in the blue-green range improves the color rendering index of the visible light output without seriously afflecting the lumen output as compared to a blend in which only the red-blue-green phosphors are used. A fifth rare earth narrow band phosphor capable of producing energy in the ultraviolet A range can be added to the blend when it is desired to simulate various phases of natural daylight. The band of ultraviolet range energy produced can be smoothed by adding to the blend another phosphor capable of producing energy in the Ultraviolet A range.

Abstract: An incandescent lamp is provided with a phosphor coating on its lamp envelope. The phosphor coating alters the spectral distribution of radiation emitted by the lamp and acts as a diffuser. In one embodiment, the phosphor coating absorbs radiation at wavelengths below 500 nanometers and emits radiation at wavelengths above 500 nanometers to provide an improved bugfoiler lamp. In another embodiment, the phosphor coating absorbs radiation in the ultraviolet, violet and blue wavelength range and emits radiation at longer wavelengths that more effectively stimulate the human eye.

Abstract: A phosphor having a continuous protective bi-layer coating of alumina surrounding silica surrounding the phosphor particles is disclosed. The method of making a bi-layer coating on phosphor particles is also disclosed. The first layer surrounding the phosphor is silica. The second layer surrounding the phosphor is alumina. The bi-layer phosphor is useful in fluorescent lamps providing improved maintenance and brightness. The bi-layer phosphor can also be used in high color rendition lamps employing blends of phosphors.

Abstract: An electrodeless low-pressure mercury vapour discharge lamp having a discharge vessel with a radiation transmitting envelope and a cavity, which cavity accommodates a core of magnetic material and a wire winding surrounding said core and connected to a high-frequency supply unit. The envelope is provided with a first luminescent layer and the cavity with a second luminescent layer. Of the two or more luminescent materials present the luminescent material with the greatest depreciation is present exclusively in the first luminescent layer on the envelope.

Abstract: A phosphor having a continuous protective bi-layer coating of alumina surrounding silica surrounding the phosphor particles is disclosed. The method of making a bi-layer coating on phosphor particles is also disclosed. The first layer surrounding the phosphor is silica. The second layer surrounding the phosphor is alumina. The bi-layer phosphor is useful in fluorescent lamps providing improved maintenance and brightness. The bi-layer phosphor can also be used in high color rendition lamps employing blends of phosphors.

Abstract: An improved mercury vapor discharge lamp is disclosed. The lamp of the present invention includes an envelope and a selectively reflecting silicon dioxide layer on at least a portion of the inner surface of the envelope. The lamp further includes a phosphor coating disposed on the selectively reflecting layer. The silicon dioxide layer has a coating weight of from about 0.1 to about 4 mg/cm.sup.2. The selectively reflecting layer comprises at least about 80 weight percent silica having a primary particle size from about 5 to about 100 nm with at least about 50 weight percent of the silica having a primary particle size from about 17 to about 80 nm.

Abstract: A phosphor composition and a lamp having a phosphor film formed of the composition. The composition contains red, green and blue luminescence components. The blue component emits blue light by the excitation of 253.7-nm ultraviolet light. It has a main luminescence peak wavelength of 460 to 510 nm, and a half width of the main peak of a luminescence spectrum of not less than 50 nm. The color coordinates of the luminescence spectrum of the blue component falls within a range of 0.15.ltoreq.x.ltoreq.0.30 and of 0.25.ltoreq.y.ltoreq.0.40 based on the CIE 1931 standard chromaticity diagram. The blue component has a spectral reflectance of not less 80% at 380 to 500 nm, assuming that a spectral reflectance of a smoked magnesium oxide film is 100%.