Abstract: A process for coating a front surface of a cathode ray, the process being characterized by using a ultraviolet ray setting plastic material as a coating material. According to the process, a preformed cathode ray tube bulb having a front surface is maintained with the front surface directed upwards and a transparent, fluidized or molten plastic material of ultraviolet setting property is discharged to the front surface of the bulb through a plurality of thin nozzles arranged in at least one row or one or more nozzles each having an elongated nozzle opening. In this instance, it is preferable that the molten plastic material discharged from the nozzles is received by a film forming surface which is arranged adjacent to the nozzles to form a thin plastic film before it reaches the front surface of the bulb. Preferably, the film forming surface is provided by a sheet of a material, such as a silicon rubber, which is not wettable to the plastic material.

Abstract: A method and apparatus for forming a fluorescent layer for a black-and-white CRT is disclosed including: a first rotation shaft installed perpendicular to the horizontal plane; a rotation table fixed to the first rotation shaft and integrally formed with a sloped portion, the table being rotated along with the first rotation shaft; a second rotation shaft installed perpendicular to the sloped surface of the sloped portion; and a deposition table fixed to the second rotation shaft and in which a bulb can be mounted.

Abstract: A method of forming a phosphor layer of a fluorescent screen of a CRT, having a good screen quality by properly managing the dissolution of a water glass and barium acetate occurring in a covering water step and improve the uniformity. A phosphor layer is formed on an inner surface of a panel portion of a glass bulb by a precipitation process and a lacquer intermediate film is formed on the phosphor layer in a state where the phosphor layer is moistened by covering water. An electrolyte remaining in the phosphor layer after the phosphor layer is moistened by the covering water has a conductivity of 6.0.+-.4.0 .mu.s/cm in 200 ml of pure water of 20.degree. C..+-.1.degree. C.

Abstract: Disclosed is a method for making a shadow mask for a color picture tube, including the steps of: forming a pattern, corresponding to apertures of the shadow mask, on a screen mesh fixed to a frame; applying metal paste on the screen mesh having the pattern; disposing a flat AK steel shadow mask under the screen mesh; printing a metal layer on a face of the flat AK steel shadow mask by squeezing the metal paste on the screen mesh with a constant pressure along a direction; and pressing the flat shadow mask to form a skirt portion and a bead portion of the shadow mask.

Abstract: The present invention discloses a flat display.The flat display is obtained by sealing an electro luminescent display which emit red and green light to a plasma display panel which emit blue light. One discharge space formed in the plasma display panel holds the red and green luminescent patterns in the electro luminescent display in common.

Abstract: A cathode ray tube includes a face plate on which are formed a first transparent layer which has a high refractive index and is conductive and a second transparent layer which has a low refractive index. Thereby, the reflectance of the outer surface of the face plate can be made low and, at the same time, an antistatic property can be obtained.

Abstract: A method of manufacturing phosphor screens is disclosed. The method uses "sol-gel" for disposing a thin film of phosphor on a transparent substrate. The thin film of phosphor is applied in continuous form or in the form of an accurate dot pattern. The rastering of said dot pattern is performed either by screen printing before annealing the sol-gel, or by selective laser curing of a continuous thin film and washing off the non-cured portions. The phosphor screens are useful as monochrome or as full-color faceplates of field emission displays or cathode ray tubes.

Abstract: A cathode ray tube in which a glass-enamel layer having particles with a secondary electron emission coefficient smaller than 1, for example Cr.sub.2 O.sub.3 particles, is provided in the neck.The percentage of particles exceeds approximately 30% and the surface resistance ranges between 10.sup.10 and 10.sup.14 .OMEGA./.quadrature.. The high-voltage behaviour of such a layer is satisfactory. The convergence drift is relatively small. In addition, a description is given of a method of providing such a glass-enamel layer.

Abstract: A method of forming a multicolor organic electroluminescent display panel is disclosed. The method uses a close-spaced deposition technique to form a separately colored organic electroluminescent medium on a substrate by transferring, patternwise, the organic electroluminescent medium from a donor sheet to the substrate.

Abstract: A fluorescent complex polymer with fluorescent organometallic complexes connected by organic chain spacers is utilized in the fabrication of light emitting devices on a substantially transparent planar substrate by depositing a first conductive layer having p-type conductivity on the planar surface of the substrate, depositing a layer of a hole transporting and electron blocking material on the first conductive layer, depositing a layer of the fluorescent complex polymer on the layer of hole transporting and electron blocking material as an electron transporting emissive layer and depositing a second conductive layer having n-type conductivity on the layer of fluorescent complex polymer.

Abstract: The present invention is to improve color purity and brightness of a color Braun tube by constructing a fluorescent film for a red fluorescent material as a laminated structure. The present invention relates to a structure of a fluorescent film for a color Braun tube wherein the fluorescent film of the red fluorescent material comprises fluorescent material layers having a laminate structure made of two different compositions of Y.sub.2 O.sub.2 S: Eu and Y.sub.2 O.sub.3 :Eu.

Abstract: An electroluminescent (EL) device includes a polymeric tetraaryl substituted biphenyldiamine.

Abstract: It is an object of the present invention to provide a color filter manufacturing method which can make the color density of a filter uniform. In order to achieve the object, according to the present invention, there is provided a color filter manufacturing method for a color filter manufactured by forming and arranging a large number of colored filter elements on a transparent substrate, including the first discharge step of discharging a colored droplet of a first volume onto each filter element formation region on the substrate so as to form each of the filter elements, and the second discharge step of discharging a droplet of a second volume smaller than the first volume onto a position on the substrate where the droplet of the first volume has been discharged.

Abstract: A method is provided for creating gated filament structures for a field emission display. A multi-layer structure is provided that includes a substrate, an insulating layer, a metal gate layer positioned on a top surface of the insulating layer and a gate encapsulation layer positioned on a top surface of the metal gate layer. A plurality of gates are provided and define a plurality of apertures on the top of the insulating layer. A plurality of spacers are formed in the apertures at their edges on the top surface of the insulating layer. The spacers are used as masks for etching the insulating layer and form a plurality of pores in the insulating layer. The pores are plated with a filament material to create a plurality of filaments. The pores can be overplated to create the plurality of filaments. The filaments are vertically self-aligned in the pores.

Abstract: In a method of coating a curved panel in a cathode ray tube, by placing on the inner surface of a panel having a curved surface a screen frame of a boat-shaped configuration across the bottom of which a screen printing screen is stretched; and by moving a squeegee pushed against the surface of the screen so that ink coated on the surface of the screen passes through the screen and prints on the inner surface of the panel, a fluorescent screen having a good and even film is fabricated on the inner surface of the cathode ray tube panel having a curved face, by a screen printing. In the method, electro-conductive terminals for electro-deposition are not required, steps are reduced, production costs are reduced, and production quality is stabilized.

Abstract: A cathode ray tube which comprises a front panel coated with a nonglare film having a multi-layered structure. The multi-layered structure comprises at least a visible light absorbing layer containing a black dye, and an antistatic layer containing an inorganic metal compound as a conductive agent.

Abstract: For use on the outer surface of a faceplate of a display device such as of the cathode ray tube (CRT) type, a first inner antistatic layer of Sb--SnO.sub.2 (particle size between 5-20 nm) is applied to a thickness in the range of 200-600 nm. The Sb--SnO.sub.2 layer has a high light refractive index (n.sub.1 =1.8) and also provides an antireflection function. After pre-heating the faceplate to a temperature in the range of 35.degree.-50.degree. C., a second intermediate antireflection layer of colloidal TiO.sub.2 (light refractive index n.sub.2 =2.0 and particle size between 5-50 nm) is applied over the first inner layer to a thickness of 100-200 nm. A third outer antireflection layer is then applied over the intermediate layer in the form of a silica gel coating at a temperature in the range of 35.degree.-45.degree. C. with a thickness in the range of 100-200 nm and a light refractive index n.sub.3. The second and third antireflective layers follow the 1/4 wavelength rule, where n.sub.3 .perspectiveto..

Abstract: An anode plate 50 for use in a field emission flat panel display device comprises a transparent planar substrate 58 having a plurality of electrically conductive, parallel stripes 52 comprising the anode electrode of the device, which are covered by phosphors 54.sub.R, 54.sub.G and 54.sub.B. A substantially opaque, electrically insulating material 56 is affixed to substrate 58 in the spaces between conductors 52, acting as a barrier to the passage of ambient light into and out of the device. The electrical insulating quality of opaque material 56 increases the electrical isolation of conductive stripes 52 from one another, reducing the risk of breakdown due to increased leakage current. Opaque material 56 preferably comprises glass having impurities dispersed therein, wherein the impurities may include one or more organic dyes, selected to provide relatively uniform opacity over the visible range of the electromagnetic spectrum.

Abstract: A multi-stage process for preparing a phosphor product includes the stages of selecting precursors of a dopant and a host lattice as the phosphor starting materials, grinding the starting materials in an initial grinding stage for an initial grinding time period to produce an initial ground material having a smaller particle size distribution than the starting materials, firing the initial ground material in an initial firing stage at an initial firing temperature for an initial firing time period to produce an initial fired material, grinding the initial fired material in an intermediate grinding stage for an intermediate grinding time period to produce an intermediate ground material having a smaller particle size than the initial fired material, wherein the intermediate grinding time period is substantially less than the initial grinding time period, firing the intermediate ground material in an intermediate firing stage at an intermediate firing temperature for an intermediate firing time to produce an in

Abstract: Siloxene and siloxene derivatives are compatible with silicon and may be generated as epitaxial layer on a silicon monocrystal. This permits the production of novel and advantageous electroluminescent devices, such as displays, image converters, optoelectric integrated circuits. Siloxene and siloxene derivatives may also be advantageously employed in lasers as laser-active material and in fluorescent lamps or tubes as luminescent material.

Abstract: A method and apparatus for coating a CRT screen after assembly. The method and apparatus includes isolating a surface portion of the CRT to be coated from the remaining surface to prevent or minimize coating problems resulting from outgassing and to isolate noncompatible components from the deposition environment.

Abstract: Electrically insulating surfaces of a cathode ray tube are covered with a film of an organic material (211). This improves the high-voltage behavior of the cathode ray tube. The film is applied by a method in which a solution comprising an organic material is applied, which is allowed to dry and is subsequently caused to decompose partly.

Abstract: A phosphor is disclosed which is suitable for use for a fluorescent display device and driven at a driving voltage as low as 1 kV or less and free of S and Cd. Compounds of Ti, alkaline earth metal and an element of Group 13 of the periodic table in predetermined amounts are heated at 1100.degree. to 1400.degree. C. for calcination, resulting in a solid solution of the rare earth element and one element of Group 13 being formed in a phosphor matrix made of an oxide of alkaline earth metal and Ti. An example of the phosphor is SrTiO.sub.3 :Pr,Al exhibiting a red luminous color.

Abstract: Provided is a method for making a thin film on a lens holder to reduce a reflection of light caused by an index difference between a refractive index of air and a refractive index of a lens-barrel of the lens holder. The thin film is formed by dipping the lens holder into a solution of a solvent and a fluororesin compound or by dripping the solution onto the lens holder. The lens holder is removed from the solution. Then, the solvent is removed to thereby form a thin film of the fluororesin compound on the lens holder.

Abstract: A process is provided for manufacturing high-purity phosphors having utility in field emission displays. The high-purity phosphor is a host lattice infiltrated by a dopant that activates luminescent properties therein. The lattice and dopant are initially milled together to reduce their average particle size while simultaneously achieving complete mixing between the lattice and the dopant. The resulting mixture is maintained free of a flux or substantially any other treatment agent capable of contaminating the phosphor and placed in a heating vessel formed from a substantially impervious contaminant-free material. The mixture is heated to a high temperature effectuating thorough infiltration of the dopant into the lattice structure. The use of an impervious contaminant-free heating vessel and the exclusion of flux or other treatment agents from the mixture avoids undesirable contamination and undue particle size growth of the phosphor product during the manufacture thereof.

Abstract: A cathode-ray tube has a faceplate on which is formed an anti-reflective coating with at least two layers. The first layer is formed on the outer surface of the faceplate by spin-coating an alcohol solution of an organometallic compound, leaving a porous metal oxide layer. The second layer is formed on the first layer by spin-coating an alcohol solution of silicon alkoxide, leaving a porous silica layer. Both layers are baked, and the first layer is baked or cured before the second layer is applied. The first layer has a higher index of refraction than the second layer.

Abstract: A method of fabricating an anode plate 18 for use in a field emission device comprising the steps of providing a transparent substrate 20 and depositing a layer of a transparent, electrically conductive material 24 on a surface of the substrate. Next, portions of the layer of conductive material 24 are removed to form regions of the conductive material. Luminescent material 26 is then applied to the conductive regions 24, and a layer of electrically conductive material 23 is applied to the luminescent material 26. Outer portions of the conductive material 23 and an outer portion 27 of at least some of the particles 25 of the luminescent material are thereafter removed.

Abstract: A method for manufacturing a screen having high luminance is provided including the steps of forming a phosphor layer on a black matrix adhered to a panel, forming a filming layer by coating and drying a filming composition containing a decomposable organic polymer and a reducing agent on the phosphor layer, forming a metal layer on the filming layer, and heating the phosphor layer, filming layer and metal layer to a temperature sufficient to decompose the filming layer.

Abstract: In a coating composition for the inner wall of a cathode-ray tube comprising an aqueous dispersion medium containing potassium silicate, a dispersing agent and graphite particles or a combination of graphite particles and metal oxide particles or metal carbide particles suspended therein, the invention is characterized in that the molar ratio of silicon dioxide to potassium oxide (SiO.sub.2 /K.sub.2 O) in said potassium silicate is in the range of from 4 to 5, and the obtained coating film is characterized in that the adsorption quantity of moisture and gases is small and adhesiveness is excellent.

Abstract: A film provided on a cathode ray tube is cured by locally subjecting it to a flow of very hot air. The gas flow heats the film without heating the underlying display window. Said gas flow is used to scan the surface.

Abstract: There is provided a phosphor screen forming method in which a metal-backing layer formed after baking can be prevented from becoming nonuniform. A phosphor layer (1), an intermediate solution film layer (2), and a lacquer film layer (3) are formed on an inner surface of a panel (P). The intermediate film layer solution contains 1 weight % of oxalic acid. The oxalic acid in the intermediate film layer solution is crystallized by evaporating and drying the intermediate film layer solution and the lacquer, and a crystallized material (4) is grown (FIG. 5A). Thereafter, an aluminum layer (5) is formed on the lacquer film layer (3) (FIG. 5B), and the intermediate solution film layer (2) and the lacquer film layer (3) are removed by baking (FIG. 5C).

Abstract: An apparatus and method for forming color video display screens of the line or stripe screen type are disclosed. Tubules form menisci of screen element liquids which are contacted with a moving display screen surface to produce screen element lines comprising the screen.

Abstract: A method for preparing an anti-reflective coating is provided which comprises the steps of applying a first coating composition containing an alcohol solution of a silicon alkoxide, at least one metal alkoxide of the formula M(OR).sub.4, an acid and water, where M is a metal selected from the group consisting of Ti, Sn, In and Zr and R is an alkyl group, on the outer surface of a panel to form a first layer; drying the panel at about 40.degree.-80.degree. C. to form a first layer; applying a second coating composition containing an alcohol solution of a silicon alkoxide, a salt selected from the group consisting of KCl, KNO.sub.3, CH.sub.3 COOK, NaCl, NaNO.sub.3, CH.sub.3 COONa, NH.sub.4 Cl, NH.sub.4 NO.sub.3 and CH.sub.3 COONH.sub.4, an acid and water onto the first layer to form a second layer; and heating the first and second layers coated on the outer surface of a panel.

Abstract: A display is constructed from translucent fluorescent plastic sheet material providing an ambient light capturing and intensifying light conduit. Area dimensions are selected appropriate to a sign or other display and a thickness is selected for structural support of the display and for capturing, intensifying and conducting ambient light along the thickness of the light conduit to intensify captured light as in a wave guide. A substantially opaque reflective layer is formed on one side of the light conduit. A decorative layer is formed over the reflective layer and is selected to provide a desired sign decor. Grooves are formed in the light conduit through the reflective decorative coating in the pattern of the selected display. The grooves are formed to a depth to intercept light captured in the light conduit. The grooves provide angled surfaces which refract, capture and illuminate light out of the light conduit.

Abstract: For use in a self-emitting color display device such as a cathode ray tube (CRT) having a display screen with a phosphor coating on its inner surface, a surface coating disposed on the display screen's outer surface affords improved color purity, or contrast, by reducing overlap in the color spectrum between two adjacent primary colors, i.e., between red and green and/or between green and blue. An organic dye is added to either an inner antistatic layer or an outer antireflective layer of an antireflective/antistatic outer coating on the display screen, where both of the aforementioned layers contain silane. The dye functions as a color filter absorbing only light within the frequency range between adjacent primary colors, such as between the red and green color phosphors, i.e., in the range of 460-500 nm, and/or between the green and blue color phosphors, i.e., in the range of 560-600 nm. A silane coupling agent is also added to serve as a binding agent bridging the organic dye and silane together.

Abstract: A coating solution composition for forming a glass gel thin film, contains at least one material selected from the group consisting of a metal alkoxide and a polycondensate of the metal alkoxide, a coloring material, an alcohol solvent, and a dispersant having an adsorption material for the coloring material, soluble in the alcohol solvent, and having miscibility with the metal alkoxide, wherein the coloring material has an average particle size of 3 nm to 300 nm. A glass gel thin film obtained by sintering this composition at a temperature of 100.degree. to 300.degree. C. is excellent in water resistance, durability and has a high strength.

Abstract: An antistatic coating was provided on a substrate 10 by dispersing latex particles 12 from a polypyrrole compound in an aqueous solution of a hydrolyzed alkoxysilane compound, after which the dispersion was applied to the substrate. The hydrolyzed alkoxysilane compound was converted to silicon dioxide by means of a treatment at an elevated temperature, thereby forming a matrix 14 in which the latex particles 12 axe dispersed and by means of which the latex particles are adhesively secured to the substrate 10. The antistatic coating can particularly be used on the display screen of a cathode ray tube, and, if desired, said coating can simultaneously be used to reduce the light transmission of the display screen.

Abstract: A thin sulfide film can be formed by simultaneously generating under different conditions a plurality of deposition materials to be deposited on a substrate, using the fact that sulfur has a higher vapor pressure. Sulfur vapors can be generated in an external vessel (6) which is located outside the vacuum deposition vessel (1). The sulfur vapors can then be introduced into the vacuum deposition vessel (1) through a vapor inlet tube (7) to form a localized atmosphere of sulfur vapors within the vacuum deposition vessel (1) in the vicinity of the substrate which is positioned on a substrate holder (4). Chemical bonding, on the substrate, of the sulfur vapors and the vapors of other deposition materials generated from other deposition sources provided in the vacuum deposition vessel (1) form a thin film of high quality with good reproducibility.

Abstract: A coating solution composition for forming a glass gel thin film, contains at least one material selected from the group consisting of a metal alkoxide and a polycondensate of the metal alkoxide, a coloring material, an alcohol solvent, and a dispersant having an adsorption material for the coloring material, soluble in the alcohol solvent, and having miscibility with the metal alkoxide, wherein the coloring material has an average particle size of 3 nm to 300 nm. A glass gel thin film obtained by sintering this composition at a temperature of 100.degree. to 300.degree. C. is excellent in water resistance, durability and has a high strength.

Abstract: The present invention relates to phosphors, composition containing phosphors and methods of their use. More particularly, it relates to organic phosphors which are amino acid salts compositions containing the phosphors and methods of using those phosphors and compositions to make objects photo-luminescent.

Abstract: A method for uniformly coating a conductive film on a panel surface is disclosed. The conductive film is applied to the panel surface by spraying a coating material through a moving nozzle in zig-zag, crosswise and perpendicular to crosswise paths. There is no area on the panel surface at which the nozzle paths cross. As a result, the coated film on the panel surface has a uniform thickness, and electric surface resistance and brightness is improved.

Abstract: To improve the uniformity and the adhesive strength of luminophore layers, a process is proposed in which the luminophore is enveloped with glass flux and the enveloped luminophore is applied to a luminophore carrier at elevated temperatures by using acrylic resin.

Abstract: An anti-reflection film is produced on the panel surface of a cathode-ray tube by:(A) preparing a solution for forming an anti-reflection film, which contains water and a metal alkoxide having the formula,M(OR).sub.nwherein M is a metal selected from the group consisting of Si, Ti, Al, Zr, Sn, In, Sb and Zn; R is an alkyl group having 1-10 carbon atoms; n is an integer of from 1 to 8; and when n is not 1, the alkyl groups represented by R may be the same or different,(B) coating the solution for forming an anti-reflection film on the outermost surface of the panel of a cathode-ray tube, and(C) applying an ultraviolet light to the solution for forming an anti-reflection film coated on said surface to cure the solution to form a transparent film with fine roughness.

Abstract: Electrolytes are attached to fluorescent particle surfaces to prevent open spots in cathode-ray tube coatings dried at high temperatures. Electrolytes that are sulfates, nitrates, or chlorides of alkali or alkaline-earth metals are added to a liquid suspension of fluorescent particles which have passed through a cleaning step. Electrolytes are added to the suspension to make the conductivity of the clear top liquid greater than 30 .mu..OMEGA..sup.-1 cm.sup.-1. The fluorescent particle preparation process is finished with a final dehydration and drying step.

Abstract: A method for reclaiming a pigment-attached red-emitting phosphor recovered from a manufacturing process for a color picture tube, which comprises treating the phosphor with an aqueous solution containing NaOH, NaClO and H.sub.2 O.sub.2 and then treating it with a weak acid, whereby the pigment can be prevented from exfoliation by suppressing the dissolution of the binder which attaches the pigment to the phosphor, and blue- and green-emitting phosphors contained as contaminants in the recovered red-emitting phosphor can be completely removed. The method provides a reclaimed red-emitted phosphor with high luminance and a good coating property.

Abstract: There is disclosed a film composition useful for reducing light glare especially adapted for use in connection with cathode-ray tube or other monitor screens which is formed from a colloidal suspension from between ten percent to thirty percent by weight of an aliphatic thermoplastic urethane resin dissolved in a blend of water, N-methylpyrrolidone and amines, mixed with between seventy percent and ninety percent by weight of Denatured Ethyl Alcohol (190 proof). The colloidal suspension is admixed with an aerosol propellant under pressure, and is deposited on a monitor screen by aerosol deposition to create a film having a thickness of between 0.5 mil and 2 mil. The deposited film dries immediately, and functions to dramatically reduce the glare of light reflecting from the screen monitor.

Abstract: The thickness distribution of a vapor deposited layer such as an interference filter deposited on a substrate such as a glass faceplate for a projection television tube, is controlled in the plane of the substrate by employing at least one variable transmission mark to partially shield the substrate during deposition.

Abstract: The invention relates to a method of coating red-luminescing phosphor particles with hematite (.alpha.--Fe.sub.2 O.sub.3), whereby first Fe(OH).sub.3 is deposited on the phosphor particles and subsequently converted into .alpha.--Fe.sub.2 O.sub.3 at a raised temperature. A good adhesion of the hematite pigments to the phosphor particles is achieved in that first an aqueous solution of an iron(III) salt and a complexing agent is prepared, in which the complexing agent and its concentration are so chosen that in combination with Fe.sup.3+ ions complex ions are formed which on the one hand do not yet precipitate at a pH-value which is at least 0.5 higher than the value at which the phosphor particles just fail to be chemically attacked anymore, and which are dissociable at a further increase in the pH-value so that Fe(OH).sub.3 is formed, in that subsequently, if the pH-value is not yet high enough, a basic substance is added to the mixture, in that the pH-value is increased to a value which is at least 0.

Abstract: The present invention relates to a novel cost efficient luminescent composition comprising particles of a core material which have been coated with a luminescent material that is distributed in the form of a chemically homogeneous layer. The average diameter of the core particle is in the range of from about 0.5 to 20 microns, and the coating corresponds to between about 2 and 30 wt % of the total composition. One aspect the invention relates to a process for preparing the composition which comprises decomposing chelated metal luminescent compositions in solution at a relatively high pH while in the presence of dispersed core particles, thereby coating the core particles with hydrous metal oxides, recovering the coated particles, optionally washing the coated particles substantially free from soluble species, drying and calcining. In another aspect, a hydrous oxide coating is converted to a sulfide coating by treating the hydrous coating with a source of active sulfur.

Abstract: A method of manufacturing a thin film electroluminescent (EL) device in which an electron beam is directed to a pellet of a substance containing an additive agent, and the substance is evaporated and deposited on a substrate and a change per unit time of the growing deposit is monitored by a sensor, comprising the steps of (1) controlling energy of the electron beam in accordance with an output of the sensor during a first time interval for adjusting an evaporation rate of the substance to a specified rate, (2) maintaining the controlled energy of the electron beam constant during a second time interval, larger than the first time interval and alternatively repeating steps (1) and (2).