Abstract: Mercury condensation in dual phosphor layer fluorescent lamps is inhibited by mixing alumina particles having a median particle size not less than about one-half micron with the phosphor particles in the first phosphor layer which is disposed adjacent the inner lamp envelope surface.

Abstract: Low-pressure mercury vapor discharge lamp in which the envelope (1) is provided on its inside with a luminescent layer (5), which comprises green luminescing Zn.sub.2 SiO.sub.4 :Mn.sup.2+ (willemite), while between the luminescent layer (5) and the envelope (1) a luminescent intermediate layer (6) is present, which comprises luminescent Sr.sub.4 Al.sub.14 O.sub.24 : Eu.sup.2+, in which the Sr may be replaced for up to 25 mol. % by Ca.

Abstract: A fluorescent lamp for use in aquaria, the luminescent layer in said lamp comprising a mixture of red, green and blue phosphors, the red phosphor emitting predominantly in the spectral region of from 610 nm to 620 nm, the green phosphor emitting predominantly in the spectral region of from 540 nm to 545 nm and the blue phosphor having a peak emission wavelength between 430 nm and 480 nm with the half peak width not exceeding 80 nm, said red, green and blue phosphors being blended to form said mixture in such proportions that the color co-ordinates of the lamp employing said mixture on the CIE chromaticity diagram differ from the point x equals 0.300 and y equals 0.232 in any direction by no more than 10 standard deviations of color matching (SDCM). Aquaria employing such lamps are also disclosed and claimed.

Abstract: In a luminescent material which comprises a first component for luminescing red light under influence of incident optical radiation and a second component for luminescing in the spectral range from 520 to 560 nm, the second component includes a first phase of garnet crystallization system consisted of yttrium aluminate activated by trivalent cerium and determined by the general structural formula Y.sub.3-a Ce.sub.a Al.sub.5 O.sub.12, wherein 0.0003<a<0.1, and a second phase of hexagonal crystallization system of general structural formula La.sub.b Ce.sub.1-b Al.sub.11 O.sub.18, wherein O<b<1, and the second phase is present in an amount ranging from the amounts detectable by means of X-ray diffractometry to the double amount of the first phase.

Abstract: Disclosed is a method for applying a continuous protective coating to the surface of individual phosphor particles. The method involves chemical vapor deposition of an aluminum oxide coating on individual particles of a phosphor powder while the particles are suspended in a fluidized bed. The particles in the fluidized bed are exposed to vaporized coating precursor material, preferably aluminum isopropoxide at a temperature above 300.degree. C. The bed is kept at as nearly an isothermal condition as possible. Prior to entering the fluidized bed the aluminum isopropoxide is vaporized and kept at a temperature less than the decomposition temperature of aluminum isopropoxide. Mechanical means are used to help increase the fluidization efficiency of the fluidized bed. After coating the phosphor particles for approximately 30 minutes the vaporized precursor material is shut off from the bed entrance and the oxygen flow rate to the fluidized bed is increased.

Abstract: A variable color lighting device employs two gases having different ionization potentials and sealed in a lamp tube. A cathode and anode are disposed inside the lamp tube opposed to each other and connected to a power supply source for varying applied voltages thereto to vary light emitting ratio of the two gases for different color light generation, in accordance with the applied voltages. A variable color lighting can be realized at relatively low voltages with a simple and economical control circuit, and an increased light emission output can be attained to render the device utilizable as a main lighting source.

Abstract: A fluorescent lamp and system for providing cosmetic tanning. The lamp includes a first ultraviolet-emitting phosphor disposed on a portion of the circumference of the interior of an ultraviolet-transmitting glass envelope. A second ultraviolet-emitting phosphor is disposed on the remaining portion the lamp envelope. The lamp further includes bases having electrical contacts extending therefrom and lying in a plane which passes through the demarcation lines formed between the first and second ultraviolet-emitting phosphors. In one embodiment, the proportions of UVB to UVA from the same light source are about 1.6 percent and 4.2 percent. In another aspect of the invention, a suntanning system includes an external reflector positioned adjacent the fluorescent lamp. The external reflector is effective in maintaining approximately the same irradiance level in the UVA region independent of the rotational alignment of the lamp.

Abstract: A fluorescent lamp and system for providing cosmetic tanning. The lamp includes a first ultraviolet-emitting phosphor disposed on a portion of the circumference of the interior of an ultraviolet-transmitting glass envelope. A second ultraviolet-emitting phosphor is disposed on the remaining portion the lamp envelope. The lamp further includes bases having electrical contacts extending therefrom and lying in a plane which passes through the demarcation lines formed between the first and second ultraviolet-emitting phosphors. In one embodiment, the proportions of UVB to UVA from the same light source are about 1.6 percent and 4.2 percent. In another aspect of the invention, a suntanning system includes an external reflector positioned adjacent the fluorescent lamp. The external reflector is effective in maintaining approximately the same irradiance level in the UVA region independent of the rotational alignment of the lamp.

Abstract: A method is disclosed for producing an aluminum oxide coated manganese activated zinc silicate phosphor which comprises forming a solution of Al.sup.+3 ions in water with the concentration of the aluminum being from about 0.01 to about 0.30 moles/l, adding manganese activated zinc silicate phosphor to the aluminum solution to form a slurry wherein the amount of phosphor is about 0.7 to about 1.0 moles per liter of slurry with agitation for a sufficient time to result in aluminum ions being adsorbed onto the surfaces of the particles of the phosphor, separating the resulting phosphor with adsorbed aluminum ions from the resulting liquor, drying the phosphor with the adsorbed aluminum ions, firing the resulting dried phosphor at a temperature of from about 750.degree. C. to about 850.degree. C.

Abstract: A fluorescent lamp suitable for backlighting a liquid crystal display includes a three-component phosphor disposed within the lamp envelope and responsive to the ultraviolet radiation generated by the plasma discharge in the lamp. The phosphor includes a first component having a first energy peak with a predetermined maximum intensity located within the wavelength range of from about 435 nanometers to 440 nanometers. A second component of the phosphor generates a second energy peak with a predetermined maximum intensity located within the wavelength range of from about 545 nanometers to 550 nanometers. A third component of the phosphor provides a third energy peak with a predetermined maximum intensity located within the wavelength range of from about 610 nanometers to 615 nanometers. The maximum intensity value of the first energy peak is within the range of from about 70% to 115% of the maximum intensity of the second energy peak.

Abstract: To permit visual observation of tanning effects obtained by a UV radiation amp, the UV radiation emitting material has admixed thereto a coating material which provides auxiliary visible radiation output in the yellow-green spectral range of between about 490-600 nm. Suitable materials are: 13% of strontium aluminate, activated with cerium; 79% of barium disilicate, activated with lead; 3% of zinc silicate, activated with manganese; and 5% of calcium halogen phosphate, activated with antimony and manganese, with the spectral ranges shown in FIG. 1, or 12% of strontium aluminate, activated with cerium; 68% of barium disilicate, activated with lead; and 20% of calcium halogen phosphate, activated with antimony and manganese, with the spectral ranges shown in FIG. 2.

Abstract: A full spectrum fluorescent lamp having a phosphor coating for producing visible light having a high color rendering index and balanced amounts of ultraviolet energy at the same correlated color temperature in which the coating is formed of two groups of phosphors, the first producing the full spectrum when excited and the second narrow bands of visible light to improve the lumen output of the lamp.

Abstract: A light-emitting composition includes a phosphor material, and an inorganic white powder material. The inorganic powder material is doped with a dopant of Ti, Ce, Cd, Cs, Sb, K, Sc, Zr, Ge, Al, Lu, La, Gd, Tb, B and/or Si. The light-emitting composition can be applied to the inner surface of a bulb of a fluorescent lamp.

Abstract: In a fluorescent lamp having a multi-layer phosphor, a halophosphate-containing layer having color coordinates within an oval centered on X=0.382 and Y=0.384. A rare earth activated phosphor layer has approximately the same color coordinates. The area density ratio of the rare earth and halophosphate-containing phosphor layers is between 0.088 to 0.222 and preferably between 0.088 to 0.133.

Abstract: A sulfide phosphor emitting green to orange light with long after-glow is represented by the formula of (ZN.sub.1-x,Cd.sub.x)S:eM.sup.I',fM.sup.III', gX' wherein M.sup.I' is at least one of copper and gold, M.sup.III' is at least one of gallium and indium, X' is at least one of chlorine, bromine, iodine, fluorine and aluminum, and x, e, f and g satisfy the conditions of 0.ltoreq.x.ltoreq.0.4, 10.sup.-8 .ltoreq.e.ltoreq.10.sup.-2, 5.times.10 .sup.-8 .ltoreq.f.ltoreq.5.times.10.sup.-3, and 5.times.10.sup.-8 .ltoreq.g.ltoreq.5.times.10.sup.-3. A white emitting phosphor is obtained by mixing the long after-glow yellow emitting phosphor represented by the above formula wherein 0.ltoreq.x.ltoreq.0.3 and 10.sup.-6 .ltoreq.e.ltoreq.10.sup.-2, with a long after-glow blue emitting phosphor. These sulfide phosphors are used to form fluorescent screens of electron excited fluorescent display devices.

Abstract: An ultraviolet fluorescent lamp for accelerated artificial test on polymer is disclosed, which comprises a bulb consisting of an ultraviolet-ray-transmitting glass with the absorbance thereof having a wavelength of 280 nm being 1 to 3 with respect to ultraviolet rays, the inner surface of the bulb being provided with a phosphor having a characteristic that causes radiant energy transmitted through the bulb to increase by 5 to 17 times for every wavelength increase of 5 nm in a wavelength range of 295 to 310 nm, and that it has a radiant energy peak in a wavelength of 305 to 325 nm.

Abstract: A fluorescent lamp having a CRI approximately the same as the CRI of the lamp phosphor is disclosed. The method includes applying a coating comprising fine particle-size silica to the inner surface of the lamp envelope to form a coated envelope, the coating having a coating weight greater than 0.7 milligrams per square centimeter and less than the weight at which lumen output of the lamp is reduced due to absorption of visible wavelength light by the silica. A coating of phosphor selected to provide a predetermined CRI is applied over the silica layer; and the coated phosphor envelope is processed into a finished lamp. A fluorescent lamp having a CRI approximately equal to the CRI of the lamp phosphor is also disclosed. The lamp of the present invention includes a lamp envelope having an inner surface; a layer of fine particle-size silica disposed on the inner surface of the lamp envelope, the silica layer containing greater than about 0.7 mg/cm.sup.

Abstract: A low pressure mercury discharge fluorescent lamp is disclosed utilizing a particular phosphor blend deposited on a calcium haloapatite phosphor base layer to achieve white color lamp illumination efficiently with improved color rendition. The surface phosphor layer is a blended mixture of a first phosphor which is divalent europium barium and/or strontium magnesium aluminate having a hexagonal crystalline structure and which further includes coactivation by divalent manganese ion sufficient to produce substantial green color emission with a second phosphor which is trivalent europium activated rare earth oxide having a rare earth ion selected from yttrium, gadolinium and lutetium, including mixtures of these rare earth ions. The underlying calcium haloapatite layer also exhibits emission at approximately the same color point as achieved with the surface phosphor layer.

Abstract: An improved suntanning fluorescent lamp having a spectral energy distribution of substantially UVA and UVB radiation. The spectral energy distribution substantially approximates natural sunlight below about 400 nanometers. Preferably, the lamp comprises a predetermined amount of a phosphor blend comprising cerium-activated strontium magnesium aluminate, europium-activated strontium pyrosphosphate and europium-activated barium pyrophosphate.

Abstract: Improvements in alternating current plasma display panels are disclosed including an imperforate intermediate structure in such a panel which provides both the function of a separator between the front and back plates (layers or structures) of the panel and the function of cross talk reducing barriers between cells of the panel. The structure includes spacing bosses which extend from the barrier structure and engage the front transparent dielectric plate, and sidewall portions intermediate adjacent pairs of spacing bosses which are separated somewhat from the front dielectric plate to provide a gas and ion passing gap between adjacent cells. In one preferred form, the sidewalls blend into a generally flat bottom wall within each cell. The sidewalls and bottom wall have a smooth or specular surface and may be coated with a reflective material to enhance cell brightness.

Abstract: Luminescent Eu.sup.2+ activated barium-hexa-aluminate mainly having the crystal structure of .beta.'-alumina and being defined by the formula (x-p)BaO.pEuO.(6-0.67x)Al.sub.2 O.sub.3 in which 0.90.ltoreq.x.ltoreq.1.22 and 0.005.ltoreq.p.ltoreq.0.25 and in which 1 to 20 mol % of the BaO is replaced by at least one of the oxides CaO and 0.67Li=.sub.2 O, exhibits improved performance as a blue line emitter.

Abstract: A fluorescent lamp utilizing a dual layer phosphor coating is disclosed and with the base layer employing a calcium halophosphate phosphor which has been modified to provide efficient lumen output at a substantially reduced coating weight. The top phosphor layer in said coating comprises a blend of narrow bandwith emitting phosphors at various coating weights primarily to improve the color rendering capability of these lamps.

Abstract: A low-pressure mercury vapor discharge lamp having a very satisfactory color rendition, (R(a,8).gtoreq.85), a color temperature of 2300-3300 K and a color point on or near the Planckian curve. The lamp is provided with a luminescent layer comprising:a. a luminescent alkaline earth metal halophosphate activated by Sb.sup.3+ and Mn.sup.2+ having a color temperature of 2900-5000 K;b. a luminescent material activated by Eu.sup.2+ with an emission maximum van 470-500 nm and a half-value width of at most 90 nm, andc. a luminescent rare earth metal metaborate activated by Ce.sup.3+ and Mn.sup.2+, having a fundamental lattice Ln(Mg,Zn,Cd) B.sub.5 O.sub.10, in which Ln represents the elements Y, La and/or Gd, which borate has red Mn.sup.2+ emission.Further, the lamp is provided with means for absorbing blue radiation having wavelengths below 480 nm. Preferably, the luminescent layer further contains:d. a luminescent material activated by Tb.sup.3+ which exhibits green Tb.sup.3+ emission.

Abstract: A fluorescent lamp utilizing a dual layer phosphor coating is disclosed wherein the base layer utilizes a first phosphor mixture and the top phosphor layer in said coating comprises a blend of narrow bandwith emitting phosphors to improve the color rendering capability of these lamps.

Abstract: According to the present invention, there is provided a phosphor represented by a general formula (Ba.sub.w Ca.sub.x Mg.sub.y Eu.sub.z)O.aAl.sub.2 O.sub.3. bSiO.sub.2 where 0.1.ltoreq.w.ltoreq.0.5, 0.0004.ltoreq.x.ltoreq.0.0020, 0.1.ltoreq.y.ltoreq.0.8, 0.03.ltoreq.z.ltoreq.0.10, w+x+y+z=1, 1.5.ltoreq.a.ltoreq.4.5, and 0.0005.ltoreq.b.ltoreq.0.0030. The present invention provides a blue-color light-emitting aluminate phosphor which has a high emission output and a low decrease in its emission intensity during use, and a fluorescent lamp using the same.

Abstract: A low-pressure mercury vapor discharge lamp with a luminescent layer whose emission mainly lies in three spectral ranges and whose loading amounts to at least 500 W per m.sup.2 surface area of the luminescent layer, is characterized by having an absorption layer of a luminescent aluminate activated by trivalent cerium and having a garnet crystal structure. The absorption layer permits the obtaining of low color temperatures (down to 2000 K.).

Abstract: A fluorescent lamp utilizing a four component phosphor combination is provided producing efficient white color illumination at a lower cost than conventional phosphor coatings of the same type. A lamp color temperature of approximately 3500.degree. K. is produced with a blend containing two strontium apatite phosphors, one strontium orthophosphate phosphor and a calcium haloapatite phosphor. The strontium phosphors are blended in weight proportions to match the white color emission point of the calcium haloapatite phosphor component in said blend.

Abstract: Low-pressure mercury vapor discharge lamp having a very satisfactory color rendition and a color temperature from 2300 to 3300 K. The lamp is provided with a luminescent layer comprising:(a) a luminescent alkaline earth metal halophosphate activated by Sb.sup.3+ and Mn.sup.2+ and having a color temperature of 2900-5000 K.;(b) a luminescent material activated by Eu.sup.2+ and having an emission maximum of 470-500 nm;(c) a luminescent rate earth metal metaborate activated by Ce.sup.3+ and Mn.sup.2+ and having a red Mn.sup.2+ emission, and(d) a luminescent aluminate activated by Ce.sup.3+ and having a garnet crystal structure absorbing blue radiation below 480 nm;(e) a green luminescing Mn.sup.2+ activated material having an emission maximum in the range from 510 to 535 nm. As a result of the addition of the material e the quantity of the material d can be limited so that color point differences among the lamps are avoided.

Abstract: A high color rendering fluorescent lamp having two-layered phosphor coating, wherein a first layer is formed immediately on the inner face of glass tube containing phosphors of alkaline earth halophosphate activated by antimony manganese or of alkaline earth holophosphate activated by antimony or both, and a second layer (an overriding layer) is formed on the first layer containing a phosphor having peak wavelength of emission at 470 nm-500 nm and absorbing line spectrum of mercury in visible short wavelength range, at least one of a phosphor of (Sr, Mg).sub.3 (PO.sub.4).sub.2 :Sn and a phosphor of (Sr, Ba).sub.3 (PO.sub.4).sub.2 :Sn.

Abstract: An improved suntanning fluorescent lamp having a spectral energy distribution of substantially UVA and UVB radiation. The spectral energy distribution substantially approximates natural sunlight below about 400 nanometers. Preferably, the lamp comprises a predetermined amount of a phosphor blend comprising cerium-activated strontium magnesium aluminate, europium-activated strontium pyrophosphate and europium-activated barium pyrophosphate.

Abstract: Calcium fluorophosphate phosphor co-activated by specific levels of antimony and manganese emits in a narrow portion of the yellow region of the spectrum making such phosphor useful in fluorescent lamps. Furthermore, when blended in specific proportions with a blue-emitting divalent europium activated strontium halophosphate, and incorporated into a fluorescent lamp, the resultant lamp gives an increased lumen per watt output over a "cool white" lamp incorporating a standard "cool white" calcium halophosphate phosphor.

Abstract: A reflector type fluorescent lamp for use in an optical apparatus, such as a copying machine, has stripe shaped main aperture 3 and narrow stripe shaped sub-aperture 4, wherein the main aperture 3 has no reflective layer 5 and no phsophor layer 6, and the sub-aperture 4 has the phosphor layer 6; the light emitted from main aperture is used to illuminate a document to be copied and another light emitted from the sub-aperture 4 is used to erase electric charge on a photosensitive material drum.

Abstract: A sunlamp whose cylindrical envelope contains a mixture of three substances the first of which emits radiation with pronounced peaks in the red, blue and green bands of the visible range of the spectrum, the second of which emits radiation with a less pronounced peak in the long-wave portion of the UVA band, and the third of which emits with an even less pronounced peak radiation in the short-wave portion of the UVA band and down to 300 nm in the UVB band. The lamp is photobiologically effective in the UV range and is sufficiently bright in the range of visible light.

Abstract: A fluorescent lamp has two layers of different phosphors, the underlying phosphor serving to improve the maintenance of the overlying phosphor.

Abstract: Disclosed is a halophosphate phosphor activated with divalent europium, which is represented by the formula:M.sub.5-a X(PO.sub.4).sub.3 :Eu.sup.2+ (a),RE(b),wherein M represents three alkaline earth metals consisting of barium, calcium and magnesium; X represents at least one of fluorine, chlorine and bromine; RE represents at least one of rare earth elements selected from the group consisting of ytterbium, neodymium, samarium, dysprosium, holmium and thulium; and a and b each represent a positive number of less than 5.Disclosed is also a fluorescent lamp which comprises a glass tube and a mixture of a halophosphate phosphor activated with divalent europium represented by the above formula and a strontium-magnesium orthophosphate phosphor activated with tin represented by the formula: (Sr,Mg).sub.3 (PO.sub.4).sub.2 :Sn, the mixture being coated on inside wall of the glass tube.

Abstract: A skin tanning lamp construction of a fluorescent type utilizing a combination of two different phosphors to provide efficient artificial skin tanning along with improved color rendition. The particular phosphor combination can be utilized as a blended mixture having a sufficient level of a phosphor constituent to impart some visible radiation in the red color region to the composite lamp emission.

Abstract: A low-pressure mercury vapor discharge lamp having a very satisfactory color rendition (R(a,8).gtoreq.85) and having a color temperature of at least 3200 K. and a color point located on or near the Planckian locus. The lamp is provided with a luminescent layer comprising:a. a luminescent alkaline earth metal halophosphate activated by Sb.sup.3+ or by Sb.sup.3+ and Mn.sup.2+b. a luminescent material activated by Eu.sup.2+ and having an emission maximum at 470-500 nm and a half-width value of at most 90 nm andc. a luminescent rare earth metal metaborate activated by Ce.sup.3+ and Mn.sup.2+ and having a fundamental lattice Ln(Mg,Zn,Cd)B.sub.5 O.sub.10, where Ln represents the elements Y, La and/or Gd, which borate has a red Mn.sup.2+ emission.

Abstract: A class of non-stoichiometric class of cerium and terbium co-activated magnesium aluminate phosphors is disclosed which are particularly useful in low pressure type fluorescent lamps. Said phosphor materials can be further combined with other phosphors to produce white color illumination in said type lamps. A general method for preparation of said phosphor materials is disclosed wherein the emission characteristics can be regulated to advantage.

Abstract: A fluorescent lamp utilizing a dual phosphor layer coating is disclosed producing efficient white color illumination at a lower cost than conventional phosphor coatings of the same type. The base layer in the phosphor coating comprises a conventional calcium haloapatite phosphor whereas the top phosphor layer comprises a tri-phosphor blend including a lanthanum cerium orthophosphate phosphor activated with terbium ion as the green color component along with a modified europium-activated yttrium oxide phosphor as the red color component.

Abstract: A low-pressure mercury vapor discharge lamp having a satisfactory color rendition (Ra.gtoreq.80), a color temperature of 2800.degree. K. or higher and a color point on or near the Planckian locus. The lamp is provided with a luminescent layer (4) which comprisesa. a luminescent rare earth metal metaborate activated by Ce and Mn and having a fundamental lattice Ln(Mg,Zn,Cd)B.sub.5 O.sub.10, where Ln represents the elements Y, La and/or Gd, which borate exhibits red Mn emission,b. a luminescent material activated by Tb.sup.3+ and having green Tb.sup.3+ emission,c. at least one luminescent halophosphate of the group which comprises the calcium halophosphates emitting white light, activated by Sb.sup.3+ and Mn.sup.2+ and having a color temperature of at least 2900.degree. K. and blue-luminescing calcium halophosphate activated by Sb.sup.3+.The lamps yield a satisfactory rendition of deep red colors (R9.gtoreq.60) and have a high luminous flux and a high maintenance of the luminous flux during the life.

Abstract: A fluorescent lamp having a phosphor film comprising:a blue-emitting phosphor consisting essentially of at least one divalent europium activated haloborophosphate phosphor having the general formula:x(M.sub.1-p.Eu.sub.p.O).yP.sub.2 O.sub.5.aM'X.sub.2.bB.sub.2 O.sub.3wherein M and M' are independently at least one of Sr, Ca and Ba; X is at least one of Cl, F and Br; and 2.7.ltoreq.x.ltoreq.3.3, 0.50.ltoreq.y.ltoreq.1.50, 0.10.ltoreq.a.ltoreq.0.50, 0.01.ltoreq.b.ltoreq.0.50, and 0.001.ltoreq.p.ltoreq.0.20;a green-emitting phosphor consisting essentially of a cerium and terbium activated silicophosphate phosphor of the general formula:(Re.sub.1-c-d-3e Tb.sub.c Ce.sub.d A.sub.3e).sub.2 O.sub.3.qP.sub.2 O.sub.5.rSiO.sub.2wherein Re is at least one of Y, La and Gd; A is at least one of Li, Na, K, Rb, and Cs; and 0<c, 0<d, 5.times.10.sup.-2 .gtoreq.e.gtoreq.1.times.10.sup.

Abstract: A fluorescent discharge lamp of improved light output having a plurality of phosphor layers stacked on a substrate of a glass tube so that the concentration of activator for the phosphor layer located near the glass substrate is less than that for the phosphor layer located at a position remote from the glass substrate, thereby to form phosphor layer having a low reflection factor to an ultraviolet ray on the electric discharge side, and a phosphor layer of enhanced quantum efficiency and high reflection factor to the ultraviolet ray on the side of the glass substrate. The ultraviolet ray generated with an electric discharge is caused to be absorbed as much as possible by the phosphor layers thereby to improve the light output. The lamp is used in, for example the field of illumination.

Abstract: Lumen maintenance in fluorescent lamps employing plural phosphor layers is improved by including alumina in the second layer; i.e., the layer closest to the discharge.

Abstract: Disclosed is a fluorescent lamp which comprises a mixture of a phosphor (i) comprising an alkaline earth metal halophosphate phosphor activated with divalent europium, represented by the general formula:M.sub.5-x X(PO.sub.4).sub.3 :Eu.sup.2+ (x)wherein M consists of Ba, Ca and Mg, containing 3 to 4.5 gram-atom of Ba, 0.5 to 2 gram-atom of Ca and 0.01 to 1 gram-atom of Mg each; X is one or more of F, Cl or Br; and 0.01<x.ltoreq.0.2and having the emission peak at the wavelength region of 480 to 500 nm, and a phosphor (ii) having the emission peak at the wavelength region of 620 to 640 nm and having the half width of 120 to 160 nm.

Abstract: An inert coating of calcium pyrophosphate in finely-divided form is provided on the inner surface of the envelope of a fluorescent sunlamp underneath the phosphor layer to reduce the emission of undesirable short-wavelength ultraviolet radiation (190 nm to 260 nm region). The relative densities of the phosphor layer and undercoating of calcium pyrophosphate are so correlated that the ratio of short-wavelength ultraviolet radiation to erythemal radiation is maintained below a prescribed limit. The particles of calcium pyrophosphate are also larger than about 1 micron and are thus adapted to selectively absorb the undesirable short-wavelength radiations and provide an integral UV-filtering means for the sunlamp.

Abstract: A luminescent screen provided with a luminescent layer formed on a carrier, which layer comprises an aluminate and/or a gallate of strontium and/or barium activated by bivalent europium or by trivalent chromium. The aluminate and/or gallate has an orthorhombic crystal structure with a space group P.sub.nnm and has a composition defined by the formula Me.sub.2-x Eu.sub.x A.sub.6-y Cr.sub.y O.sub.11 (Me=Sr, Ba and A-Al, Ga).An advantageous application of such a luminescent screen is found in low-pressure mercury vapor discharge lamps.

Abstract: A skin tanning lamp construction of a fluorescent type is described utilizing a combination of two different phosphor materials in order to provide a more effective sun tanning source. The particular phosphor combination can be utilized as a blended mixture having a preselected level of one phosphor component to limit the amount of erythemal radiation produced by said mixture.

Abstract: A fluorescent lamps having colors similar to standard daylight can be prepared using two component compositions. A blue emitting phosphor having a peak emission with a specified range and a 50% band width within a specified range along with specific amounts of a yellow-emitting phosphor having a 50% band width within a specified range and a peak emission within a specified range provide a daylight lamp with a higher lumer per watt than the standard daylight lamp.

Abstract: A flourescent lamp, having a vacuum tight radiation transmitting envelope comprising mercury and rare gas, provided with electrodes between which the discharge takes place during operation and a luminescent layer which comprises a mixture of phosphors having different densities wherein the greater the density of the phosphor, the smaller its particle size.

Abstract: A meal vapor discharge lamp having an outer jacket, the inside wall of which is covered by a fluorescent layer comprising at least one red emitting phosphor whose emission peak is in a wavelength range of 610-630 nm and whose luminescence forms a line, said lamp containing an arc tube within the confines of said outer jacket which encloses zinc and/or cadmium in addition to mercury as the main luminous components.