EP0466138B1 - Entladungslampe mit Kaltkathode - Google Patents
Entladungslampe mit Kaltkathode Download PDFInfo
- Publication number
- EP0466138B1 EP0466138B1 EP19910111508 EP91111508A EP0466138B1 EP 0466138 B1 EP0466138 B1 EP 0466138B1 EP 19910111508 EP19910111508 EP 19910111508 EP 91111508 A EP91111508 A EP 91111508A EP 0466138 B1 EP0466138 B1 EP 0466138B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- bulb
- cold cathode
- electron emitting
- emitting substance
- discharge lamp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000126 substance Substances 0.000 claims description 75
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 43
- 229910052724 xenon Inorganic materials 0.000 claims description 34
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 claims description 34
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 22
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 2
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 claims 2
- 239000000395 magnesium oxide Substances 0.000 claims 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims 1
- 239000011787 zinc oxide Substances 0.000 claims 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 229910052782 aluminium Inorganic materials 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 239000000203 mixture Substances 0.000 description 5
- 239000000725 suspension Substances 0.000 description 5
- 229910025794 LaB6 Inorganic materials 0.000 description 4
- JJWKPURADFRFRB-UHFFFAOYSA-N carbonyl sulfide Chemical compound O=C=S JJWKPURADFRFRB-UHFFFAOYSA-N 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 230000005684 electric field Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 2
- 229920000742 Cotton Polymers 0.000 description 2
- 150000004703 alkoxides Chemical class 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- FUZZWVXGSFPDMH-UHFFFAOYSA-M hexanoate Chemical compound CCCCCC([O-])=O FUZZWVXGSFPDMH-UHFFFAOYSA-M 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 150000002894 organic compounds Chemical class 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- GCAAQROFKRZNKT-UHFFFAOYSA-N [Tb].[Ce] Chemical compound [Tb].[Ce] GCAAQROFKRZNKT-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229960005363 aluminium oxide Drugs 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N ferric oxide Chemical compound O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- LQFNMFDUAPEJRY-UHFFFAOYSA-K lanthanum(3+);phosphate Chemical compound [La+3].[O-]P([O-])([O-])=O LQFNMFDUAPEJRY-UHFFFAOYSA-K 0.000 description 1
- HTUMBQDCCIXGCV-UHFFFAOYSA-N lead oxide Chemical compound [O-2].[Pb+2] HTUMBQDCCIXGCV-UHFFFAOYSA-N 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- -1 mercury ions Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 229910052754 neon Inorganic materials 0.000 description 1
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 description 1
- 229910052756 noble gas Inorganic materials 0.000 description 1
- 238000000424 optical density measurement Methods 0.000 description 1
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/30—Vessels; Containers
- H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/04—Electrodes; Screens; Shields
- H01J61/06—Main electrodes
- H01J61/067—Main electrodes for low-pressure discharge lamps
- H01J61/0675—Main electrodes for low-pressure discharge lamps characterised by the material of the electrode
- H01J61/0677—Main electrodes for low-pressure discharge lamps characterised by the material of the electrode characterised by the electron emissive material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/54—Igniting arrangements, e.g. promoting ionisation for starting
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
- H01J61/76—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a filling of permanent gas or gases only
- H01J61/78—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a filling of permanent gas or gases only with cold cathode; with cathode heated only by discharge, e.g. high-tension lamp for advertising
Definitions
- the present invention relates to a cold cathode discharge lamp with a phosphor film formed inside the bulb, and particularly relates to a cold cathode xenon discharge lamp.
- the initial electrons triggering discharge include thermoelectrons, photoelectrons, electrons emitted by a high electric field, and cosmic rays in the nature.
- thermoelectrons When a discharge lamp is left in dark atmosphere where no external light reaches, startup is difficult because cosmic rays are present as initial electrons since no photoelectron is present.
- photoelectrons When the lamp is used in completely-shielded housing or casing, startup by photoelectrons cannot be expected because light in the nature may hardly reach.
- thermoelectrons a heating-type electrode with a complicated structure is necessary because thermoelectrons are supplied by heating the electrode with thermoelectron emitting material.
- the starting characteristic in the dark is inferior because the cold cathode does not emit thermoelectrons for startup.
- the cold cathode xenon discharge lamp has a disadvantage that the starting characteristic of the lamp in the dark is inferior.
- CaO does not preferably function in the complete dark because it does not emit electrons unless there is external light. Therefore, it is inferior in reliability.
- Prior art document EP-A-0 348 979 discloses a fluorescent lamp apparatus which includes a fluorescent lamp comprising a discharge tube having a discharge space filled with a gas conductive to light emission and cold cathode type electrodes sealed one at each end of the tube.
- a phosphor layer is coated on an inner surface of the tube and a high-frequency lighting circuit supplies a high-frequency electric power.
- a light-transmitting electric insulation layer made of alumina is provided between the phosphor layer and the inner surface of the tube.
- the fluorescent lamp apparatus is of such a type that mercury ions within the discharge space are prevented by the insulating layer from intruding in the wall of the tube.
- prior art document US-A-4 914 723 discloses a fluorescent lamp discharge tube having an electrostatically coated envelope.
- the coating comprises a mixture of 100 parts by weight of phosphor, 0,01 to 3 parts by weight of a fatty acid having a melting point greater than 40°C, or the ammonium, aluminium alkaline earth salts thereof, and 0,05 to 5 parts by weight of finely divided aluminiumoxide having a grain size smaller than 0,1 micron.
- the phosphor is applied to the tube by a venturi effect and results in a more uniformly applied coating than is provided using a suspension coating. Uniformity of the coating is measured by the disclosed optical densitometry test.
- the present invention provides a cold cathode discharge lamp as specified in claim 1.
- Fig. 1 is a sectional view of the cold cathode xenon discharge lamp used for the back light of an liquid crystal display (LCD), in which numeral 10 represents a glass bulb.
- LCD liquid crystal display
- the bulb 10 in this embodiment is made of a straight tube having approximately circular cross section with the outside diameter of 6.5 mm, the inside diameter of 5.0 mm, and the overall length of, for example, 270 mm, in which a discharge space 11 is specified.
- the both ends of the bulb 10 is sealed by a button stem 12.
- Two electrodes 20 is installed on these stems 12 respectively.
- the electrodes are separate by 250 mm from each other.
- the electrode 20 is a cold cathode which includes an electrode body 21 made by forming a nickel plate into a cylinder and a lead wire 22 connected to the electrode body 21.
- the lead wire 22 passes through the button stem 12 with it kept airtight and is led to the outside.
- the above discharge space 11 of the bulb 10 is filled with discharge gas consisting of 100% xenon gas at the pressure of 13 332 Pa (100 Torr).
- discharge gas consisting of 100% xenon gas at the pressure of 13 332 Pa (100 Torr).
- Mixture gas between xenon and noble gas such as argon or neon may be used for the discharge gas instead of 100% xenon gas.
- the inner surface of the bulb 10 exposed to the discharge space 11 is coated with a phosphor film 15 excluding the both ends or portions close to electrodes.
- the phosphor film 15 is made of cerium-terbium activation aluminate phosphor emitting green light with the peak wavelength of approx. 540 nm.
- the phosphor is not restricted to the above substance. It is also possible to use a general three-band phosphor made by mixing three phosphors having luminous areas of blue, green, and red respectively.
- the electron emitting substance referred in this specification means a substance which emits electrons by the stimulus energy equal to or less than the work function in the dark. Such stimulus energy may be a thermal energy of for example, a soon temperature of 25°C.
- the electron emitting substance layer 18 is made of translucent metallic oxide such as ⁇ -alumina, ⁇ -alumina (Al2O3), magnesia (MgO), zinc oxide (ZnO), and lead oxide (PbO).
- This embodiment uses a layer made of ⁇ -alumina powder for the electron emitting substance layer 18 because it is stable in the electron emitting characteristic.
- Such an electron emitting substance is known in BRITISH JOURNAL OF APPLIED PHYSICS, Vol. 9, March 1958, "A survey of exo-electron emission phenomena".
- the above electron emitting substance layer 18 made of alumina can be formed by, for example, mixing butyl acetate with fine-grain alumina and cotton bromide to make suspension, applying the suspension around the electrodes on the inner surface of the bulb 10, and baking it to form ceramic.
- an alumina film can be formed by applying organic compound aluminum solution (e.g. alkoxide aluminum solution) to the inner surface of the bulb 10 and drying it before baking to form it as an alumina film.
- organic compound aluminum solution e.g. alkoxide aluminum solution
- the above electron emitting substance layer 18 is directly exposed to the discharge space 11, that is, it is not covered with the phosphor film 15.
- the phosphor film 15 formed in the inner surface of the bulb 10 is not extended up to the portion close to the electrode 20 but the electron emitting substance layer 18 is formed at the portion free from the phosphor film.
- the above cold cathode xenon discharge lamp is turned on at the high frequency of 50 KHz through a high-frequency transistor inverter (not illustrated).
- the cold cathode xenon discharge lamp having the above configuration is easily started in the dark and the starting duration is greatly decreased.
- the electron emitting substance layer 18 formed on the inner surface of the bulb 10 or the alumina film always emits electrons by receiving thermal energy from peripheral atmosphere without being provided with a high electric field even in the dark at the ordinary temperature.
- the cold cathode xenon discharge lamp is quickly turned on in a space interrupted from cosmic rays in the dark.
- the electron emitting substance layer 18 is not covered with the phosphor film 15, the electrons are emitted to the discharge space at a high probability and discharge breakdown is prompted. That is, because the electron is a low-speed electron, the probability for the electrons to be emitted to the discharge space decreases because it is absorbed by the phosphor film 15 when the electron emitting substance layer 18 is covered with the phosphor film 15 and lighting may be delayed though it is not so late as the prior art.
- the insulating property of the phosphor film 15 depends on the grain size, grain size distribution, and relative contact electrification amount of the phosphor composing the film. Therefore, when the electron emitting substance layer 18 is covered with the phosphor film 15, the number of electrons to be emitted from the electron emitting substance layer 18 depends on the type of the phosphor used.
- the electron emitting substance layer 18 is formed so that it will be exposed to the discharge space without covering it with the phosphor film 15, the number of electrons to be emitted to the discharge space increases and the probability to cause discharge breakdown increases.
- the illuminance distribution is not greatly affected because the area free from the phosphor film 15 is close to the electrode even if the phosphor film 15 is not formed at the portion.
- the electron emitting substance layer 18 is formed so that it will face the electrode 20 installed at the both ends of the bulb 10 respectively.
- the electron emitting substance layer 18 has a structure independent of the phosphor film 15.
- the electron emitting substance layer 18 can be installed only on one of the electrodes 20.
- the electron emitting substance layer 18 is formed so that it will be exposed inside the bulb 10.
- the electron emitting substance layer 18 is formed so that it will have the dimension approximately same the phosphor film 15.
- FIG. 1 shows the case in which an internal electrodes are sealed in the both ends of the bulb 10 respectively.
- Fig. 5 shows this embodiment.
- This fourth embodiment uses a bulb 10 with the overall length of 70 mm, the outside diameter of 2.5 mm, and the inside diameter of 1.4 mm, in which a cold cathode 20 consisting of a nickel cylinder with the overall length of 2.5 mm and the outside diameter of 0.7 mm is installed on one end of the bulb and an external electrode 30 extending in the bulb axis direction in the form of a belt is installed on the outer surface of the bulb 10.
- the electron emitting substance layer 18 is formed as a ring on the inner surface of the bulb 10 close to the internal electrode 20.
- the phosphor film 15 formed on the inner surface of the bulb 10 is made of lanthanum phosphate, which emits umber light. Discharge gas consisting of 100% xenon gas is sealed in the bulb 10 at the pressure of 13 332 Pa (100 Torr).
- the lamp having the above configuration is suitable for meter pointers.
- the above cold cathode xenon discharge lamp starts within a very short time even in the dark because the electron emitting substance layer 18 not covered with the phosphor film 15 is formed in the inner surface of the bulb 10 so that it will face the cold cathode 20.
- the electron emitting substance layer 18 is formed closely to the internal electrode 20. However, as shown in Fig. 6, it is possible to form the electron emitting substance layer 18 separately from the internal electrode. For this embodiment, though the electron emitting substance layer 18 is formed on the surface of the phosphor film 15, it is also possible to form it directly on the end of the bulb 10.
- the electron emitting substance layer 18 is formed under the phosphor film 15 or between the phosphor film 15 and the inner surface of the bulb 10.
- the electron emitting substance layer 18 is formed so that it will have the dimension approximately same as the phosphor film 15, it can also be formed only at a portion close to at least one electrode.
- the electron emitting substance layer 18 can be covered with a metallic thin layer 40.
- the structure of the metallic layer 40 is not restricted to that shown in Fig. 8. Any type of structure can be applied as long as the electron emitting substance layer 18 is exposed.
- the electron emitting substance layer 18 is installed on the bulb 10 side, that is, it is secured to the bulb.
- the bulb 10 can be installed on the electrode side. This embodiment is shown below.
- the cold cathode discharge lamp shown in Fig. 9 is the same as that shown in Fig. 3 except the fact that the electron emitting substance layer 18 is formed on the electrode 20. Therefore, description is made for the electrode 20.
- the electrode body 21 of the electrode 20 is filled with an electron emitting substance 23 made of lanthanum boride LaB6 together with nickel. That is, the electrode body 21 is made by filling it with mixture of nickel powder and LaB6 power of 10 to 20 capacity percent and cold-forming and swagging it before heat-treating it to melt the nickel powder and deposit LaB6.
- the electron emitting substance 23 made of LaB6 is held by the electrode body 21.
- the electron emitting substance 23 emits electrons by the stimulus energy equal to or more than the work function, which is used to induce discharge when the starting voltage is applied and different from the substance forming the electron emitting substance layer 18.
- a layer 18 made of an electron emitting substance (e.g. ⁇ -alumina) is formed on the outer surface of the electrode 20.
- the electron emitting substance layer 18 made of the alumina can be formed by, for example, mixing butyl acetate with fine-grain alumina and cotton bromide to make suspension, applying the suspension to the outer surface of the electrode 20, and baking it to form ceramic.
- an alumina film can be formed by applying organic compound aluminum solution (e.g. alkoxide aluminum solution) to the inner surface of the bulb 10 and drying it before baking to form it as an alumina film.
- organic compound aluminum solution e.g. alkoxide aluminum solution
- the cold cathode xenon discharge lamp with the above configuration like the above embodiment, easily starts in the dark and the starting duration can greatly be decreased.
- the electron emitted from the electron emitting substance layer 18 formed on the outer surface of the electrode 20 triggers discharge and the cold cathode xenon discharge lamp is quickly turned on in a dark space interrupted from cosmic rays.
- the electron emitting substance layer 18 is installed on the electrode 20, the electrons emitted from the electron emitting substance layer 18 securely reach the discharge space and effectively work for discharge breakdown without being absorbed in the tube wall and, thus, many electrons contribute to start of discharge. Therefore, stable startup is possible.
- the electron emitting substance layer 18 is applied to the outer surface of the electrode body 21 of the electrode 20.
- the electron emitting substance 18 instead of the electron emitting substance 23 to emit electrons with the stimulus energy equal to or more than the work function.
- either electrode can be an external electrode similarly to the embodiment shown in Fig. 5.
- the layer 18 is formed in the bulb 10 by the electron emitting substance.
- the electron emitting substance may be formed in the bulb 10 by any means.
- the phosphor electron emitting substance layer 50 made of mixture of phosphor and electron emitting substance on the inner surface of the bulb 10.
- the mixture layer 50 serves as a phosphor film and electron emitting substance layer.
- the idea of the present invention can also be applied to the discharge lamp with electrodes installed outside as shown in Fig. 15.
- a pair of stripped external electrodes 30 are installed on the outer surface of the bulb 10 so that they will face each other.
- the following three ideas are embodied: the idea to install the layer made by electron emitting substance at the bulb side, the idea to install it at the electrode side, and the idea to mix the electron emitting substance in the phosphor film.
- Fig. 16 shows the result of measuring the delay of the discharge starting time of typical embodiments among the above embodiments and that of a sample according to the prior art using no electron emitting substance.
- the abscissa shows the discharge start delay time (Sec) and the ordinate shows the cumulative discharge starting rate.
- the following five types of samples are used: 100 samples 1 made by forming the electron emitting substance layer ( ⁇ -alumina layer) 18 closely to electrodes as shown in Fig. 1, 100 samples 2 made by filling the electron emitting substance 18 in the electrode as shown in Fig. 11, 100 samples 3 made by mixing electron emitting substance ( ⁇ -alumina) with phosphor as shown in Fig.
- the phosphor film of every sample is formed by yttrium oxide.
- These manufactured samples are aged for a certain time. Then they are left in a bright place (1,000l x) for 12 hr and a dark place (0l x) for 12 hr. This operation is repeated seven times, so that they are left as they are for 168 hr then, the 1.2 kV sinusoidal wave (35 KHz) is applied to them in a dark place of 25°C. In this case, the time until the lamp current flows is measured.
- the sample 1 is the most preferable because it has the shortest discharge start delay time.
- the samples 2 through 4 are preferable compared with the sample 5 according to the prior art.
- the profile of the above bulb can be circular, elliptic, or flat oval and the bulb shape can be not only straight but U-type.
- the present invention is applied to the lamp with a cold cathode inside the bulb.
- the cold cathode lamp has an inferior starting characteristic in the dark because it does not have the structure in which the cold cathode emits thermoelectrons at start.
- xenon is sealed in the bulb, that is, for a cold cathode xenon discharge lamp, ionization hardly occurs, the starting voltage rises, and it takes time for startup because the ionization characteristic of xenon is inferior.
- the present invention is effective for the above cold cathode xenon discharge lamp.
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- Discharge Lamp (AREA)
- Discharge Lamps And Accessories Thereof (AREA)
- Surface Treatment Of Glass (AREA)
- Vessels And Coating Films For Discharge Lamps (AREA)
Claims (10)
- Kaltkathoden-Entladungslampe mit:
einem Kolben (10), der darin einen Entladungsraum (11) hat,
einem Entladungsgas, das in dem Entladungsraum (11) des Kolbens (10) eingeschlossen ist und ein Edelgas enthält,
Kaltkathodenelektroden (20, 30), die das Entladungsgas eine Entladung verursachen lassen, und
einer Exo-Elektronenemissionssubstanz (18, 50), die in dem Kolben (10) installiert ist und Elektronen durch thermische Emission in den Entladungsraum des Kolbens (10) emittiert,
dadurch gekennzeichnet, daß die Exo-Elektronensubstanz (18, 50) in dem Kolben als eine Schicht von sich selbst installiert ist und in den Entladungsraum (11) des Kolbens freiliegt, um direkt Elektronen in den Kolben (10) zu emittieren. - Kaltkathoden-Entladungslampe nach Anspruch 1, dadurch gekennzeichnet, daß das Edelgas wenigstens Xenon umfaßt.
- Kaltkathoden-Entladungslampe nach Anspruch 1 oder 2, gekennzeichnet durch Leuchtstoffilme (15, 50), die auf der Innenflächenseite des Kolbens (10) gebildet sind.
- Kaltkathoden-Entladungslampe nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die Exo-Elektronenemissionssubstanz (18, 50) eine festgelegte Schicht in dem Kolben (10) aufweist.
- Kaltkathoden-Entladungslampe nach Anspruch 4, dadurch gekennzeichnet, daß die Exo-Elektronenemissionssubstanz-Schicht nahezu wenigstens einer der Kaltkathodenelektroden (20, 30) installiert ist.
- Kaltkathoden-Entladungslampe nach Anspruch 4, dadurch gekennzeichnet, daß die Kaltkathodenelektroden (20, 30) getrennt in dem Kolben (10) in einem gewissen Intervall installiert sind, und daß die Exo-Elektronenemissionssubstanz-Schicht an dem Kolben (10) nahe zu wenigstens einer Elektrode festgelegt ist.
- Kaltkathoden-Entladungslampe nach Anspruch 4 oder 5, dadurch gekennzeichnet, daß die wenigstens eine Elektrode (20) einen zylindrischen Hohlkörper aufweist, und daß die Exo-Elektronenemissionssubstanz-Schicht in dem Körper festgelegt ist.
- Kaltkathoden-Entladungslampe nach Anspruch 4 oder 5, dadurch gekennzeichnet, daß die Elektrode (20) einen zylindrischen Hohlkörper hat, und daß die Exo-Elektronenemissionssubstanz-Schicht an der Außenfläche des zylindrischen Hohlkörpers festgelegt ist.
- Kaltkathoden-Entladungslampe nach Anspruch 4, dadurch gekennzeichnet, daß wenigstens eine der Elektroden (20, 30) außerhalb des Kolbens (10) installiert ist, und daß die Exo-Elektronenemissionssubstanz an dem Kolben so festgelegt ist, daß sie der wenigstens einen Elektrode gegenüberliegt.
- Kaltkathoden-Entladungslampe nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, daß die Exo-Elektronenemissionssubstanz gebildet ist durch wenigstens einen Stoff aus Aluminiumoxid, Magnesiumoxid, Zinkoxid und Bleimonooxid.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP182823/90 | 1990-07-12 | ||
JP02182823A JP3080318B2 (ja) | 1990-07-12 | 1990-07-12 | けい光ランプおよびこれを用いた照明装置ならびに液晶表示装置 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0466138A1 EP0466138A1 (de) | 1992-01-15 |
EP0466138B1 true EP0466138B1 (de) | 1995-11-29 |
Family
ID=16125087
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19910111508 Expired - Lifetime EP0466138B1 (de) | 1990-07-12 | 1991-07-10 | Entladungslampe mit Kaltkathode |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0466138B1 (de) |
JP (1) | JP3080318B2 (de) |
DE (1) | DE69114929T2 (de) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100529890C (zh) * | 2003-12-30 | 2009-08-19 | 乐金显示有限公司 | 背光单元 |
US7633216B2 (en) | 2005-11-28 | 2009-12-15 | General Electric Company | Barium-free electrode materials for electric lamps and methods of manufacture thereof |
US8007123B2 (en) | 2001-12-19 | 2011-08-30 | Samsung Electronics Co., Ltd. | Blacklight with power supply clips and liquid crystal display device including such backlight |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5495143A (en) * | 1993-08-12 | 1996-02-27 | Science Applications International Corporation | Gas discharge device having a field emitter array with microscopic emitter elements |
DE10125212A1 (de) * | 2001-05-18 | 2002-11-21 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Glimmzünder |
JP5484833B2 (ja) * | 2008-08-29 | 2014-05-07 | 宇部マテリアルズ株式会社 | 蛍光体粉末組成物 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB8306375D0 (en) * | 1983-03-08 | 1983-04-13 | Emi Plc Thorn | Electrostatically coating phosphor onto envelopes |
JPH079795B2 (ja) * | 1986-12-01 | 1995-02-01 | 東芝ライテック株式会社 | 放電ランプ |
JPH0212751A (ja) * | 1988-06-30 | 1990-01-17 | Toshiba Lighting & Technol Corp | 高周波点灯式けい光ランプ |
-
1990
- 1990-07-12 JP JP02182823A patent/JP3080318B2/ja not_active Expired - Lifetime
-
1991
- 1991-07-10 EP EP19910111508 patent/EP0466138B1/de not_active Expired - Lifetime
- 1991-07-10 DE DE1991614929 patent/DE69114929T2/de not_active Expired - Fee Related
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8007123B2 (en) | 2001-12-19 | 2011-08-30 | Samsung Electronics Co., Ltd. | Blacklight with power supply clips and liquid crystal display device including such backlight |
CN100529890C (zh) * | 2003-12-30 | 2009-08-19 | 乐金显示有限公司 | 背光单元 |
US7633216B2 (en) | 2005-11-28 | 2009-12-15 | General Electric Company | Barium-free electrode materials for electric lamps and methods of manufacture thereof |
Also Published As
Publication number | Publication date |
---|---|
EP0466138A1 (de) | 1992-01-15 |
JPH0471155A (ja) | 1992-03-05 |
DE69114929D1 (de) | 1996-01-11 |
JP3080318B2 (ja) | 2000-08-28 |
DE69114929T2 (de) | 1996-07-25 |
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