Patent Application
20080036383
The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein:
Referring to
At least one end of the sealed tube 21 has an air duct 211 formed by glass, through which the air is evacuated from the sealed tube 21 to a desired vacuum and then the sealed tube 21 is filled with a glow discharge medium, for example, a glow discharge medium of inert gases (Argon, Neon, Krypton, and mixed gas thereof) and mercury. The mercury can be pure mercury, a mercury-containing substance, or a mixture of mercury and metal halides, such that a glow-discharge light with corresponding wavelengths, for example, ultraviolet light, visible light, infrared light or mixture thereof is emitted by the glow discharge medium when the glow discharge medium is excited. Alternatively, pure sodium or sodium-containing substances can be further added into the glow discharge medium. Then the outward end of the air duct 211 is sealed, such that the sealed tube 21 is also sealed. In addition, the sealed tube 21 is formed by a material that can be transmitted by the glow-discharge light emitted by the electrical-glow-discharge of the glow discharge medium, for example, glass.
The electrode sets 12 are assembled on two ends of the sealed tube 21, and are contacted with the glow discharge medium. When an electrical voltage is applied to the electrode sets 12, the electrode sets 12 provide electrical power to the glow discharge medium to generate the electrical-glow-discharge of the glow discharge medium for emitting the glow discharge light.
The passive luminous material 22 is coated on the outer surface of the sealed tube 21 to form a passive luminous coating layer, wherein the passive luminous layer absorbs the glow-discharge light emitted by the glow discharge medium to emit a luminescence light with corresponding wavelength. In particular, the passive luminous material 22 can be mixed with a binder such as glass powder or polymers, and the mixture is then coated by brushing or spraying, etc. on the outer surface of the sealed tube 21.
The passive luminous material 22 can be visible-emitted-material that emits visible light by absorbing the glow-discharge light, such as a short-afterglow luminous material, a long-afterglow luminous material, or the mixture thereof in any proportion. Here, the long-afterglow luminous material is a passive luminous material whose time period to decay the luminous intensity to 50% is longer than one minute after the absence of the glow discharge light. On the contrary, if the time period is less than 1 minute, the material is the short-afterglow luminous material.
In specific, the short-afterglow luminous material can be short-afterglow phosphor powder, wherein the monochromatic phosphor includes red Y203:Eu, green Ce0.67Tb0.33MgAl11O19 or Zn2SiO4:Mn, blue Sr5(PO4)3Cl:Eu or BaMg2Al16O27:Eu, and polychromatic phosphor include yellow, cyan, orange, white (Ca5(PO4)3F:Sb3+,Mn2+), etc., or a mixture of monochromatic red, green, and blue phosphor. The long-afterglow luminous material can be long-afterglow phosphor powder, wherein the monochromatic phosphor includes red CaAl2O4:Eu, Nd, green SrAl2O4:Eu, Dy, blue Sr4Al14O25:Eu, Dy, the polychromatic phosphor includes yellow, cyan, orange, white (CaAl2O4:Dy3+), etc., or a mixture of monochromatic red, green, and blue phosphor. The passive luminous materials 22 can be monochromatic materials, polychromatic materials, or a mixture of a plurality of monochromatic materials.
The passive luminous material 22 is coated on the outer surface of the sealed tube 22 by various methods, for example, stirring the phosphor powder, a solvent, and a binder into a paste, brushing or spraying the paste with an air gun onto the outer surface of the sealed tube 22, and then drying at 80° C. and baking at 200-400° C. to remove the solvent. The binder described above can be a polymer or glass powder, or a mixture thereof. In addition, a conductive layer which can be transmitted by the glow-discharge light of the glow discharge medium can be coated between the outer surface of the sealed tube 21 and the passive luminous coating layer in advance, for example, the conductive layer can be an oxide conductive layer with the thickness of 0.5-1 μm (indium tin oxide, zinc aluminum oxide, tin antimony oxide, or fluorine tin oxide), or an metal thin layer (Au, Ag, Ni or Al with the thickness of less than 30 nm). Then the phosphor powder is coated on the outer surface by the electrophoresis or electrostatic coating methods. Then, through a baking process, the solvent is removed, and the binder strength and optical transmittance are improved. The above-mentioned polymer material is a material that can be transmitted by visible light, for example, polyvinyl chloride (PVC), polycarbonate (PC), poly methylmethacrylate (PMMA), and polyurethane (PU), etc.
A protective layer 23 is further coated on the passive luminous coating layer formed by the passive luminous material 22, and the luminescence light emitted by the passive luminous coating layer formed by the passive luminous material 22 can transmit the protective layer 23, so as to enhance the transmittance of visible light, protect the passive luminous material 22 from peeling off due to external forces, and prevent the dust and grease contaminating the surface of the passive luminous material 22, which helps to keep the surface clean. The protective layer 23 of the embodiment can be formed by oxide conductors (such as indium tin oxide, zinc aluminum oxide, tin antimony oxide, or fluorine tin oxide), oxide nonconductors (such as magnesia), glass, or polymers (such as PVC, PC, PMMA, or PU), with a thickness of 0.5-5 μm. The polymers aforementioned can be polyvinyl chloride (PVC), poly methylmethacrylate (PMMA), polyurethane(PU), and the like.
When the protective layer 23 is formed by glass, the protective layer 23 can be formed by glass coatings (with pastes made of SnO—ZnO—P2O5 glass powder, solvent, and amyl acetate binder) or glass sol-gel which have a low softening point (lower than 60° C.) and are able to be transmitted by visible light. The passive luminous material 22 is coated first, then is coated with glass coatings, and finally is placed into the high-temperature oven for baking, thus forming the compact glass film to serve as the protective layer 23 to protect the passive luminous material 22. In addition, the thermal evaporation or ion sputtering methods can also be used to grow the glass protective layer 22 on the surface of the passive luminous material 22.
As the refractive index of the transparent oxide conductors, transparent oxide nonconductors, polymers, or glass is lower than that of the passive luminous material, the protective layer 23 formed by these materials can increase the transmittance of light.
Referring to
Referring to
Furthermore, infrared light-emitting material, visible light-emitting material, and ultraviolet light-emitting material can be mixed to form a single passive luminous layer, or forming a visible light-emitting coating 22a, an infrared light-emitting coating layer 22b, and ultraviolet light-emitting coating layer 22c stacking on each other, for absorbing the glow-discharge light to emit a luminescence light of the combination of visible light, infrared light, and ultraviolet light. For increasing the transmittance of the mixing light (such as combination of visible light and infrared light, visible light and ultraviolet light, infrared light and ultraviolet light, or visible light, infrared light, and ultraviolet light), the protection layer 23 on the luminous material 22 sometimes is not used.
Referring to
At least one end of the sealed tube 21 has an air duct 211 formed by glass, through which the air is evacuated from the sealed tube 21 to a desired vacuum and then the sealed tube 21 is filled with glow discharge medium, for example, a glow discharge medium of inert gases (Argon, Neon, Krypton, and mixed gas thereof) and mercury. The mercury can be pure mercury, or a mercury-containing substance, or a mixture of mercury and metal halides, such that a glow-discharge light with corresponding wavelengths, for example, ultraviolet light, visible light, or mixed light of ultraviolet light and visible light is emitted by the glow discharge medium when the glow discharge medium is excited. Then the outward end of the air duct 211 is sealed, such that the sealed tube 21 is the sealed. In addition, the sealed tube 21 is formed by a material that can be transmitted by the glow-discharge light emitted by the electrical-glow-discharge of the glow discharge medium, for example, glass.
The electrode sets 12 are assembled on two ends of the sealed tube 21, and are contacted with the glow discharge medium. When an electrical voltage is applied to the electrodes sets 12, the electrode sets 12 provide electrical power to the glow discharge medium to generate the electrical-glow-discharge of the glow discharge medium for emitting the glow discharge light.
Referring to
The passive luminous material 22 is coated on surface of the supporting body by various methods, for example, stirring the fluorescent powder, a solvent, and a polymer binder into the paste, and brushing, dipping, or spraying the paste with an air gun, and then drying at 80° C. and baking at 200-400° C. to remove the solvent. The passive luminous material 22 can be a short-afterglow luminous material, a long-afterglow luminous material, or a mixture thereof.
In addition to passive luminous material 22 formed with a single layer that emits visible light, the passive luminous material 22 can also be an infrared light-emitting material that emits infrared light by absorbing visible light or ultraviolet, or an ultraviolet light-emitting material that emits ultraviolet with long wavelength of 280 nm-400 nm by absorbing ultraviolet with short wavelength of 253 nm or shorter. The passive luminous material 22 can also be combination of plural light-emitting materials for emitting combination light. Furthermore, the passive luminous material 22 can be formed with plural layers stacking on each other for emitting visible light, infrared light, ultraviolet, or the combination of visible light, infrared light and ultraviolet. The passive luminous material 22 can be coated on the outer surface of the supporting body as shown in
Referring to
Referring to
Referring to
Conventionally, the luminous materials are made into powder, i.e., after the crystalline structure is achieved by sintering, the block materials are smashed and ground into fine powder. This process may cause defects to the luminous crystals, such as residual strains and micro cracks, which greatly reduce the luminescence efficiency. In addition, when the phosphor powder is formed subsequently, the power must be mixed with the solvent and the organic or inorganic binder and stirred into a paste, and then the paste is coated on the surface of a supporting body. The grinding during the mixing may damage the surface of the phosphor powder, and the subsequent heating process for removing the organic substance and drying the powder may change the oxidation state of the luminous center of the phosphor powder, thus reducing the luminescence efficiency.
Therefore, the present invention provides the luminous tube or luminous plate formed through sintering. The fabricating method involves evenly mixing the raw materials by the solid state method, the chemical co-precipitation method, or the sol-gel method, and forming the desired phase structure of the luminous powder through the calcining reaction, grinding the reaction products into fine powder, mixing the powder with appropriate polymer binder, forming the luminous tube or luminous plate through inject molding, and then obtaining the luminous tube or luminous plate through sintering in a high-temperature oven. As the luminous powder used is subjected to a high temperature (normally over 1300° C.) process, the luminous tube or luminous plate is characterized by stability and acid/alkali resistance. The luminous material naturally is a kind of ceramic material and has an appropriate strength, and thus it is a fine structural material. As for fluorescent lamps with specific light-emitting direction, if a small-size bulb-shaped or planar sealed tube 21 is used, a luminous plate for generating visible light is preferred. In addition to those similar to those of the luminous tube, the luminous plate can also be fabricated by the scraper method, the powder metallurgy method, or the slurry-casting method, and then sintered in the high-temperature oven.
In this embodiment, the sealed tube 21 and the passive luminous body 31 are fabricated separately, and then assembled to form the structure of fluorescent lamp 30. Thus, the cooling effect of the phosphor powder of the passive luminous body 31 increases, so the passive luminous body 31 formed by the phosphor material can be kept at a lower temperature during operation, which helps to improve the luminescence efficiency and stability of the passive luminous body 31. Furthermore, as the sealed tube 21 is shielded by the phosphor tube 313 from the air in the environment, the temperature of the tube wall of the sealed tube 21 can be easily kept stable, and is not affected by the flowing of the air in the environment, and thus the luminous intensity becomes more stable.
In order to improve the luminous intensity, the surface exposed to air of the phosphor tube 313 or phosphor plate 314 formed by the passive luminous material in this embodiment can be coated with a material which can be transmitted by the light emitted by the passive luminous material and has a refractive index lower than that of the passive luminous material. The suitable material are, for example, oxide conductors (such as indium-tin oxide, zinc-aluminum oxide, tin-antimony oxide, or fluorine-tin oxide), oxide nonconductors (such as magnesia), glass, or polymers, etc.
Common characteristics of the aforementioned embodiments will be described below. When the structures of fluorescent lamp 20, 30 of the aforementioned embodiments are used, the electrode sets 12 provide electrical power to the glow discharge medium, such that the glow discharge medium filled in the sealed tube 21 is excited to emit light. As the passive luminous layer 22 or the passive luminous body 31 absorbs the glow-discharge light to emit a visible light, such as monochromatic red, green, blue, or polychromatic yellow, cyan, orange, and white, thus can be used for illuminating.
When the passive luminous coating layer 22 or the passive luminous body 31 of the structures of fluorescent lamp 20, 30 are formed by the short-afterglow phosphor powder, the operating mode is the same as that of the conventional fluorescent lamp, i.e., continuously supplying power to the electrode sets 12. However, when the passive luminous coating layer 22 or the passive luminous body 31 of the fluorescent lamp structures 20, 30 is formed by the long afterglow phosphor powder or combined with the long afterglow phosphor powder, the operating mode is continuously or discontinuously supplying power. If the discontinuously supplying power, the power consumption can be reduced, and the temperature of the tube wall of the seal tube 21 can be reduced.
The long-afterglow luminous material described above can be a high-luminance Sr—Al—O family materials with long-afterglow. When the exciting light is absent, the Sr—Al—O family material can continuously emit light that is visible to human eyes for 12 hours, in which the luminance decays slowly with time.
The present invention combines the long afterglow material and the sealed tube 21 of the fluorescent lamp. By adding an appropriate power control circuit, the operating mode of the fluorescent lamp can be changed to be a discontinuous power supply, such that the power source of the electrode sets 12 is turned on or off at a predetermined time. That is, the power source is turned on at first, such that the glow discharge medium in the sealed tube 21 releases the exciting light, and the exciting light is then absorbed by the long-afterglow phosphor powder, coated on the outer wall of the sealed tube 21. A part of the excited phosphor powder returns to the ground state to release the visible light, and a part of exciting energy is stored to release the visible light later. Therefore, the long-afterglow phosphor powder not only releases the visible light for illuminating at once, but also stores the exciting light source.
After the energy stored in the long-afterglow phosphor powder is saturated (the saturation time of storage relates to the material and thickness of the long-afterglow phosphor powder), the power source of the electrode sets 12 can be turned off, and the light energy absorbed by the long-afterglow phosphor powder is released in the form of visible light, so as to provide the illumination.
When the luminescence provided by the long-afterglow phosphor powder decreases to lowest brightness required, the power source 12 can be turned on again (the on/off of the power source 12 is controlled according to the experimental time value, or is controlled by disposing a light sensor beside the structures of fluorescent lamp 20, 30 to provide a signal to a controller), such that the required continuous luminance is provided, and the power supply time can be reduced, and thus the power is saved, the temperature of the structures of fluorescent lamp 20, 30 is reduced, and the luminescence efficiency of the passive luminous material is enhanced.
In addition, the structure of fluorescent lamp provided by the present invention combining the long-afterglow material and the sealed tube 21 can be used at night, in basements, or in office buildings that cannot be illuminated by sunshine. If the power is accidentally cut off, the excited long-afterglow material can keep emitting light that is visible for over 12 hours in darkness, the afterglow light can be used in emergency treatment or evacuation from the buildings, and additional emergency lamps are not required.
Moreover, for users who cannot fall asleep because of be afraid of the dark environment after the lamp is turned off, the luminance of the fluorescent lamp with the long-afterglow material decreases gradually after it is turned off. Thus the present invention can overcome the problem described above, and help to improve the quality of sleep. Therefore, in addition to reducing the power consumption (especially being applied to long-time illumination such as street lamps and advertisement signs), the structures of fluorescent lamp structures 20, 30 with the long-afterglow material of the present invention provide the functions of emergency and safety instructions when the power is accidentally cut off.
Since most damages of the fluorescent lamp occur at the filament electrodes of the sealed tube 21, when the lamp is out of order, only the sealed tube 21 needs to be replaced according to the structures of fluorescent lamp 20, 30 of the embodiments. The damaged sealed tube 21 can be recycled. A new sealed tube 21 can be fabricated by removing the electrode sets 12 of the sealed tube 21, recycling the residual mercury, cleaning, replacing new electrode sets 12, combining the electrode sets 12 and the glass tube, evacuating, charging inert gases and appropriate amount of mercury liquid droplets again, and sealing the air duct 211. Thus, the environmental problem caused by the mercury-containing phosphor powder in conventional waste fluorescent lamps can be largely reduced, and the raw material consumption of the glass, phosphor powder, and mercury, etc. of the sealed tube 21 is greatly reduced. Thus, a large amount of material resources can be saved.
providing a sealed tube 21 (Step S11) filled with the glow discharge medium containing argon and mercury. The tube wall of the sealed tube 21 can be transmitted by the exciting light generated by glow discharge medium, and is made of a glass;
disposing a pair of electrode sets 12 (Step S12) on two ends of the sealed tube 21 and contacting the glow discharge medium;
disposing a passive luminous material 22 (Step S13) coated outside the sealed tube 21, in which the passive luminous material 22 is formed by a long-afterglow material, or a mixture of a short-afterglow material and a long-afterglow material, and furthermore, the passive luminous material 22 can be further mixed with an binder to facilitate the fabrication of a passive luminous body or facilitate the coating of the passive luminous material 22;
disposing a protective layer 23 (Step S14) coated on the passive luminous material 22, in which the protective layer 23 is formed by glass of low melting point or a organic polymer material;
disposing a on-off control circuit 41 (Step SI 5) between the pair of electrode sets 12 and a power source, in which as the passive luminous 22 keeps working for a period of time after absorbing the exciting light generated by glow discharge medium even if it doesn't absorb the light energy anymore, the operating time of the exciting light that is generated by exciting the glow discharge medium in the sealed tube 21 can be controlled by the on-off control circuit 41 through discontinuously supplying the power; and
disposing a light sensor 42 (Step S16) connected to the on-off control circuit 41, for detecting the luminous intensity of the passive luminous material 22, in which when the luminance of the passive luminous material 22 decays to a certain degree, the light sensor 42 provides signals to the on-off control circuit 41 to supply power for a period of time to excite the glow discharge medium in the sealed tube 21, such that the glow discharge medium in the sealed tube 21 releases light energy again which is absorbed by the passive luminous material 22. After the glow discharge medium in the sealed tube 21 emits the exciting light for a period of time, the power for engaging the glow-discharge of the glow-discharge medium is shut-off again by the on-off control circuit 41 again. The above-mentioned procedures are repeatedly operated.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
