CA1293765C - Rare gas discharge lamp with an external electrode - Google Patents
Rare gas discharge lamp with an external electrodeInfo
- Publication number
- CA1293765C CA1293765C CA000542098A CA542098A CA1293765C CA 1293765 C CA1293765 C CA 1293765C CA 000542098 A CA000542098 A CA 000542098A CA 542098 A CA542098 A CA 542098A CA 1293765 C CA1293765 C CA 1293765C
- Authority
- CA
- Canada
- Prior art keywords
- tube
- discharge lamp
- gas discharge
- envelope
- external electrode
- 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
- 239000007789 gas Substances 0.000 claims description 69
- 239000000463 material Substances 0.000 claims description 25
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 10
- 229910052724 xenon Inorganic materials 0.000 claims description 6
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 claims description 6
- 229910052786 argon Inorganic materials 0.000 claims description 5
- 229910052734 helium Inorganic materials 0.000 claims description 4
- 239000001307 helium Substances 0.000 claims description 4
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 4
- 229910052754 neon Inorganic materials 0.000 claims description 4
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 claims description 4
- 229910052743 krypton Inorganic materials 0.000 claims description 3
- DNNSSWSSYDEUBZ-UHFFFAOYSA-N krypton atom Chemical compound [Kr] DNNSSWSSYDEUBZ-UHFFFAOYSA-N 0.000 claims description 3
- 239000003990 capacitor Substances 0.000 description 9
- 238000005286 illumination Methods 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 5
- 238000002834 transmittance Methods 0.000 description 5
- 239000003822 epoxy resin Substances 0.000 description 4
- 229920000647 polyepoxide Polymers 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- OOJYPCDXFPWXFL-UHFFFAOYSA-N [C].OC1=CC=CC=C1 Chemical compound [C].OC1=CC=CC=C1 OOJYPCDXFPWXFL-UHFFFAOYSA-N 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/24—Means for obtaining or maintaining the desired pressure within the vessel
- H01J61/26—Means for absorbing or adsorbing gas, e.g. by gettering; Means for preventing blackening of the envelope
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
- H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
-
- 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
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters
- H05B41/2806—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters with semiconductor devices and specially adapted for lamps without electrodes in the vessel, e.g. surface discharge lamps, electrodeless discharge lamps
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Electromagnetism (AREA)
- Vessels And Coating Films For Discharge Lamps (AREA)
- Discharge Lamps And Accessories Thereof (AREA)
Abstract
Abstract of the Disclosure A gas discharge lamp has a discharge gas sealed within a cylindrical-shaped tube through which light is transmitted. Internal and external electrodes are pro-vided, as first and second receiving ends, respectively, on the side of the same end of the tube with the inter-nal electrode located within the tube and provided along the axial direction of tube outside of the tube except for a location where a slit is provided. A high fre-quency power source is connected to the internal and external electrodes and upon the application of a high frequency power to the internal and external electrodes a discharge occurs within the tube.
Description
This invention relates generally to a gas discharge lamp and, more particularly, to an improved gas discharge lamp in which a fluorescent material layer is formed on the inner surface of a tube, and a discharge gas is sealed within the tube.
Generally, in gas discharge lamp, a pair of elec-trodes of mutually opposite polarities are mounted and sealed in a cylindrical-shaped tube with a rare gas or low mercury vapor pressure sealed therein. It is, however, very difficult to mount and seal the electrodes in the tube, due to the small diameter of the tube (e.g.
an inner diameter of less than 10 mm). Furthermore, a longer sealing time is required, because both the electrodes are sealed within the tube.
When, for example, a glow discharge is generated within the tube, across a space separating the elec-trodes, a low-level light emission occurs on fluorescent material layer which is located behind each electrode, that is, at the "tube end portion" side, away from each electrode.
As a result, the effective light emission length (electrode-to-electrode distance) becomes short, rela-tive to the length of the tube. In order to obtain a predetermined length of light emission, it has been necessary to determine the light emission length to a predetermined length. It is therefore necessary to determine the length of the tube in accordance with the effective light emission length.
Accordingly, demand has increased for a gas discharge lamp having a simplified electrode sealing structure, as well as for an increase in the effective light emission length in relation to the tube length.
To this end U.S. Patent No. 4,645,979 discloses, in detail, a gas discharge lamp with one of a pair of electrodes as an external electrode and the other as an internal electrode.
This particular arrangement ensures a ready sealing mounting in comparison with the case where both electrodes are mounted and sealed in the tube. Since, in this case, the external electrode is formed up to the end of the tube, the length from the internal electrode to the external electrode, i.e., the effective light emission length, can be made longer.
In such gas discharge lamp, however, it is not difficult to vary the effective light emission length. The electrodes are externally taken out in the same direction from the tube.
That is, a connection means is required at the ends of the tube to connect lead-in wires to an external power source, requiring a cumbersome operation. Furthermore, a predetermined spacing is required in such an operation.
The present invention . ~
~9~;'t)5 provideSa gas discharge lamp which can decrease an operation spacing for a connecting means to connect electrodes to an external power source, without pro-viding the electrodes one on each end side of that tube.
A gas discharge lamp according to this invention comprises a cylindrical-shaped tube having a discharge gas therein and through which light is passed, an inter-nal electrode provided at a tube end, and an external electrode provided outside of the tube along an axis of the tube, the internal and external electrodes respec-tively having a portion provided near the tube end for receiving energy to cause the discharge within the tube.
A gas discharge lamp apparatus according to another embodiment of this invention comprises a gas discharge lamp device including a cylindrical-shaped tube filled a discharge gas therein and through which light is passed, an internal electrode provided at a tube end, an external electrode provided outside of the tube along an axis of the tube, the internal and external electrodes respectively having a portion provided near the tube end, and a high frequency power source for applying to the portions a high frequency power to cause a gas discharge within the tube so that light is directed.
These and other features and advantages of this invention will become more apparent from the following 1;~9~
detailed description of exemplary embodiments as illustrated in the accompanying drawings in which:
Fig. 1 is a general view showing a gas discharge lamp according to a first embodiment of this invention;
Fig. 2 is a cross-sectional view, as taken along line I-I line, showing the lamp of Fig. 1;
Fig. 3 is an outer, perspective view showing the lamp of Fig. l;
Fig. 4 is a schematic view, generally showing a gas discharge lamp according to a second embodiment of this invention;
Fig. 5 is a cross-sectional view, as taken along line II-II, showing the lamp of Fig. 4; and Fig. 6 is a cross-sectional view, partly enlarged, showing a third embodiment of this invention gas discharge lamp of this invention.
A rare gas discharge lamp apparatus according to a first embodiment of this invention will be explained below by reference to Figs. 1 to 3.
In Fig. 1, discharge lamp 10 includes tube 12 of a cylindrical configuration with each end closed. Tube 12 is made of a light-transmissive quartz glass or a hard or soft glass and has, for example, internal diameter of below 2 mm, or external diameter of below 3 mm.
A rare gas of at least one kind selected from the group consisting of xenon, krypton, argon, neon, helium, etc. is sealed into tube 12 with xenon as a principal 1~9;~
component in which case a light output varies in pro-portion to the rare gas pressure level.
Within tube 12, internal electrode 14 made of, for example, nickel is provided at one end of the tube and serves as one of a pair of electrodes. An emitter mate-rial is coated on the surface of the internal electrode 1.2 mm in outer diameter to facilitate an electron emis-sion. Internal electrode 14 is sealingly mounted by a "pinch-sealing" method. Lead-in wire 16 which penetra-tes through the end wall of tube 12 in a gas-tight fashion is connected to internal electrode 14 and sealed within tube 12.
Fluorescent material layer 18 is formed on the inner surface of tube 12 such that the thickness of the film varies along the axis of the tube, for the reason set forth below.
That is, if the fluorescent material layer is uni-formly formed within tube 12 throughout the length of the tube, a luminance level becomes high at a position, for example, substantially two-thirds the whole length of the tube as viewed from internal electrode 14. In such a luminance distribution, the luminance level is decreased frGm the aforementioned position toward the end of tube 12.
For this reason, the thickness of fluorescent material layer 18 is so set as to obtain a transmittance of 25 to 40~. That is, the thickness of fluorescent 1~937~
material layer 18 is decreased at the position sub-stantially two-thirds the whole length of the tube as viewed from internal electrode 14 so that the transmittance exceeds 40%. In this case the thickness of fluorescent material layer 18 is gradually increased toward the end of the tube.
External electrode 20 is intimately attached to the outer side portion of tube 12 and serves as the other electrode. That is, external electrode 20 is formed from end to end across the whole length of the tube, that is, in a direction in which lead-in wire 16 to internal electrode 14 extends, to provide a band of a substantially uniform width along the axis of the tube.
External electrode 20 is formed of an electroconductive coating film which is obtained by coating, for example, a copper/carbon blend paste on the surface portion of the tube and sintering it.
Light shielding film 22 is formed on the external surface of tube 12 with an opening, such as slit 24, formed opposite to band-like external electrode 20 to allow passage of a predetermined quantity of light.
Stated in more detail, light shielding film 22 is formed over the whole surface of tube 12 except for slit 24, that is, over the outer tube surface including the outer surface of external electrode 20, with the width of slit 24 formed substantially uniformly across the whole length of the tube.
1~37~iS
In tube 12, first receiving end film 14a is formed on the outer surface portion of that tube end portion with internal electrode 14 sealed within the tube, that is, on the outer surface of light shielding film 22.
First receiving end film 14a is formed of an electrocon-ductive paste, such as silver--epoxy resin. First receiving end film 14a is connected to lead-in wire 16 which is connected to internal electrode 14.
Second receiving end film 20a is formed on the outer surface of tube 12 in an axially spaced-apart relation to first receiving end film 14a. Second receiving end film 20a is also formed of an electro-conductive paste, such as silver-epoxy resin and circum-ferentially so provided in the axially spaced-apart relation to first receiving end film 14a as to have a predetermined width. Second receiving end film 20a is formed on the outer surface of light shielding film 22, not on slit 24, and connected to external electrode 20.
Internal electrode 14 and external electrode 20 are connected to high frequency power source 28 through first receiving end film 14a and second receiving end film 20a and directly and through current-limiting capa-citor 26, respectively. High frequency power source 28 is comprised of inverter circuit 30, frequency generat-ing section 40 and power source 50.
Inverter circuit 30 is of such a push-pull type that transformer 32 has its primary winding connected to 1~9~'7~5 the collectors of switching transistors 34a and 34b and its secondary winding connected to discharge lamp 10.
Switching transistors 34a and 34b have their emitters connected to each other with a common junction coupled to a negative terminal (-) of variable D.C. power source 50 in the power source and their base-to-emitter circuits connected to a series circuit of resistors 36a and 36b.
Switching transistors 34a and 34b have their bases connected to I.C. 42 (e.g. TL494, Texas Instruments Inc) which, together with variable capacitor 44 and variable resistor 46, provides a frequency generating circuit.
Variable capacitor 44 and variable resistor 46 are grounded.
I.C. 42 is connected to both the terminals of D.C.
power source 50 to supply the voltage of D.C. power sup-ply 50. D.C. power source 50 has its positive terminal (+) connected to a predetermined location on the primary winding side of transformer 32 through coke coil 38.
In the gas discharge lamp, a high frequency power is supplied from D.C. power source 50 through first and second receiving ends 14a and 20a and through push-pull inverter 30 to internal electrode 14 and external electrode 20. At this time, the frequency employed is set to a proper value (20 to 45 KHz in this embodiment) by frequency generating section 40 comprised of I.C. 42, variable capacitor 44 and variable resistor 46.
3~ii g When current is supplied to internal electrode 14 and external electrode 20, the direct current is con-verted to an alternating current with the aforemen-tioned proper frequency through push-pull inverter 30.
A glow discharge corresponding to a lamp current of below 20 mA occurs across internal electrode 14 and external electrode 20 within tube 12 with the use of the aforementioned high frequency current. As a result of such glow discharge, fluorescent material layer 18 is excited by a resonance line of the rare gas within tube 12 to produce visible light. The visible light is emitted as a narrow beam pattern to the outside of tube 12 through slit 24.
Upon the occurrence of the aforementioned glow discharge the current density is decreased at a location remote from internal electrode 14 and external electrode 20. Since, however, fluorescent material layer 18 is so set as to obtain a transmittance of 25 to 40~ as already set out above, the luminance level is increased in a location remote from the aforementioned electrodes.
Even in the location nearer to internal electrode 14 and external electrode 20 the thickness of fluorescent material layer 18 is likewise so set as to obtain a transmittance of 25 to 40% and, even if electrons coming from internal electrode 14 never have a distance adequate to be accelerated, the luminance level is increased.
Furthermore, at the location substantially 1~3~6S
two-thirds the whole distance of tube 12 as viewed from internal electrode 14 the thickness of fluorescent material layer 18 is so set as to obtain a transmittance of over 40% and the luminance level is decreased at that location.
As a result, the luminance level is relatively increased at each end portion of tube 12 and decreased at the location substantially two-thirds the whole length of tube 12 as viewed from internal electrode 14.
By so doing, the luminance distribution tends to be made uniform as a whole within tube 12.
According to this invention, since the terminal or lead-in wire (the connecting means as the receiving end) of the internal electrode sealed within the tube and that of the external electrode extend from the same end of the tube, the lamp of this invention can reduce the operation spacing of said connecting means to one half that required in the conventional lamp.
From this it follows that light external emitted from tube 12 is restricted to only a light beam which is transmitted through slit 24. For this reason, the illu-mination light is directional in nature and is oriented only in the direction in which slit 24 is formed. Since the width of slit 24 can be made smaller than the diameter of tube 12, the illumination light can be transmitted, as a very narrow beam, through slit 24.
The outline of the illumination light becomes much lZ93765 sharper relative to the background becomes of the illu-mination of the light only through slit 24.
In the case of cylindrical-shaped discharge lamp 10, external electrode 20 is formed up to the end of tube 12 and thus the emission length of discharge lamp 10 corresponds to a distance from internal electrode 14 to the end of tube 12, offering a longer effective emission length. This means that it is not necessary to increase the length of the tube per se.
In discharge lamp 10, if the aforementioned high frequency power is adequately high, leakage current tends to flow b ~ween external electrode 20 and a dis-charge space wi/thin tube 12, allowing the capacitor's function to adequately reach the end of the tube. If, on the other hand, the aforementioned frequency power becomes lower, then the light emission length becomes shorter due to the failure of the capacitor's function to reach the end of the tube. It is therefore, pos-sible to freely vary the light emission length if the aforementioned frequency power is made variable.
Where, for example, the voltage of variable D.C.
power source 50 is varied or where the capacitance or resistance of variable capacitor 44 or variable resistor 46, respectively, in the frequency generating circuit is varied to cause a variation in frequency involved, then the aforementioned high frequency power varies in either case, causing a variation in a flow of leakage current 1;~93~6S
between externa] electrode 20 and the discharge space within tube 12. Therefore, the capacitor's function and thus the light emission length vary.
A rare gas discharge lamp according to a second embodiment of this invention will be explained below by reference to Figs. 4 and 5 jointly.
In Figs. 4 and 5, the internal arrangement of dis-charge lamp 10' is the same as the first embodiment.
That is, discharge lamp 10' includes tube 12 having fluorescent material layer 18 formed in the inner sur-face thereof. The thickness of fluorescent material layer 18 varies along the axis of tube 12 for the same reason as set forth in connection with the aforemen-tioned first embodiment. Further explanation is, there-fore, omitted.
The second embodiment is the same as the afore-mentioned embodiment with respect to the constituents of rare gas sealed within tube 12, gas pressure, internal electrode 14 provided within the tube at one end of the tube and lead-in wire 16.
External electrode 20' is formed on the whole outer surface of tube 12 except for slit 24 formed along the axis of tube 12. External electrode 20' is made of a light shielding material, such as carbon, and that outer surface portion of the tube not covered by external electrode 20', that is to say, slit 24' provides an opening through which light is emitted.
1~3~i5 Internal electrode 14 and external electrode 20' are connected to high frequency power source 28 directly and through current-limiting capacitor 26, respectively.
High frequency power source 28 is comprised of push-pull inverter 30, frequency generating section 40 and power source 50. That is, high frequency power source 28 is the same as that of the aforementioned embodiment.
Further explanation is, therefore, omitted.
In the gas discharge lamp, a high frequency power is supplied from D.C. power source 50 through push-pull inverter 30 to internal electrode 14 and external electrode 20'. Upon the supply of current to internal electrode 14 and external electrode 20' a glow discharge corresponding to a lamp current of below 20 mA is pro-duced across internal electrode and external electrode 20'. As a result, fluorescent material layer 18 is excited by a resonance line of a rare gas within tube 12 to produce visible light. The visible light is exter-nally emitted from within the tube through slit 24'.
In the second embodiment, the lead-in wires are also provided in the same direction of the tube, per-mitting the spacing of the connecting means to be halved as in the first embodiment when compared with the con-ventional lamp, and external electrode 20' covering the outer surface of tube 12 serves also as a light shield-ing film, ensuring a simpler structure than in the case where the light shielding film and external electrode 7~iS
are formed in separate steps. It is also easier to form the light shielding film.
The light emitting from within tube 12 is restricted only to light which has been transmitted through slit 24'. The illumination light is directional in nature, that is, is oriented only in the direction in which slit 24' is formed. Since the width of slit 24' is smaller than the diameter of tube 12, the illumina-tion light is emitted as a very narrow light beam through slit 24'.
The aforementioned gas discharge lamp is of such a type that a rare gas only is used. This rare gas discharge lamp utilizes the negative glow section of the glow discharge, offering such an advantage that the light output is not temperture-dependent.
The aforementioned gas discharge lamp does not need to be restricted only to the glow discharge and may be applied to an arc discharge in which case the inter-nal electrode is partially thickened so that a hot cathode is inserted therein.
The material to be sealed within the tube is not restricted only to the rare gas and this invention can equally be used as a low mercury vapor pressure discharge lamp. In a practical lamp using Hg sealed therein, for example, a very small amount of Hg of about 0.1 mg may be sealed at an argon pressure of 3 Torrs within the same tube as the rare gas discharge lamp.
1;~93~5 The fluorescent material layer is not necessarily required, because a special gas for emitting visible light may be sealed within the gas discharge lamp. For example, argon, neon and helium emit pink, orange and red purple color visible light, respectively. Further-more, a low mercury vapor pressure discharge lamp pro-duces visible light as an ultraviolet lamp of a narrow beam pattern source.
Fig. 6 shows another variant of a combination of internal and external electrodes and external power source of a third embodiment with one end portion shown enlarged. Tube 12 has fluorescent material layer 18 in the inner surface thereof and external electrode 20 on the outer surface portion thereof. External electrode 20 is obtained by bonding, for example, carbon phenol or silver-epoxy resin on the outer surface of tube 12 in a band-like fashion in the axial direction of the tube and sintering it. In this case, electrode 20 has a predeter-mined width along substantially the whole length of the tube. The resultant structure is covered by light shielding film 22 except at a location where slit 24 is formed. External electrode 20 is connected at one end to lead-in wire 20c in the axial direction of the tube.
Lead-in wire 20c is comprised of a covered cord and has its inner conductor jointed by soldering or silver-epoxy resin to one end of external electrode 20 at the loca-tion of connection portion 20b.
1~93~65 Recess 60 is formed as a mode at that location of tube 12 where lead-in wire 20c is taken out. Recess 60 provided a circumferentially continued groove, but it may be formed as one circumferential portion only.
In tube 12, insulating shrinkable tube 62 is fitted over recess 60 and connection portion 20b between exter-nal electrode 20 and lead-in wire 20c. Shrinkable tube is of a heat shrinkable type, such as vinylchloride or polyester, and intimately fitted over the base portion of the tube, that is, over connection portion 20b and lead-in wire 20c. In this way, connection portion 20b between external electrode 20 and lead-in wire 20c, as well as recess 60, are covered by shrinkable tube 62.
On the other hand, internal electrode 14 is sealed within the tube and brought out of the tube through lead-in wire 16.
In this embodiment, the other component parts, as well as the operation, are the same as in the aforemen-tioned first and second embodiments and any further explanation is, therefore, omitted.
In the third embodiment, a connection space at the receiving end can be reduced to one half that required in the conventional lamp. Since the base portion of lead-in wire 20c are firmly attached to tube 12 by shrinkable tube 62, even if any displacement of lead-in wire 20c relative to tube 12 occurs, for example, in a direction as indicated by an arrow in Fig. 6, it never propagates 1~937~iS
over connection portion 20b and thus no stress is pro-duced in connection section 20b, thus preventing a breakage of lead-in wire 20c.
Since shrinkable tube 62 is engaged with recess 60 at the end portion of tube 12, there is no possibility that is will slip out of tube 12.
Generally, in gas discharge lamp, a pair of elec-trodes of mutually opposite polarities are mounted and sealed in a cylindrical-shaped tube with a rare gas or low mercury vapor pressure sealed therein. It is, however, very difficult to mount and seal the electrodes in the tube, due to the small diameter of the tube (e.g.
an inner diameter of less than 10 mm). Furthermore, a longer sealing time is required, because both the electrodes are sealed within the tube.
When, for example, a glow discharge is generated within the tube, across a space separating the elec-trodes, a low-level light emission occurs on fluorescent material layer which is located behind each electrode, that is, at the "tube end portion" side, away from each electrode.
As a result, the effective light emission length (electrode-to-electrode distance) becomes short, rela-tive to the length of the tube. In order to obtain a predetermined length of light emission, it has been necessary to determine the light emission length to a predetermined length. It is therefore necessary to determine the length of the tube in accordance with the effective light emission length.
Accordingly, demand has increased for a gas discharge lamp having a simplified electrode sealing structure, as well as for an increase in the effective light emission length in relation to the tube length.
To this end U.S. Patent No. 4,645,979 discloses, in detail, a gas discharge lamp with one of a pair of electrodes as an external electrode and the other as an internal electrode.
This particular arrangement ensures a ready sealing mounting in comparison with the case where both electrodes are mounted and sealed in the tube. Since, in this case, the external electrode is formed up to the end of the tube, the length from the internal electrode to the external electrode, i.e., the effective light emission length, can be made longer.
In such gas discharge lamp, however, it is not difficult to vary the effective light emission length. The electrodes are externally taken out in the same direction from the tube.
That is, a connection means is required at the ends of the tube to connect lead-in wires to an external power source, requiring a cumbersome operation. Furthermore, a predetermined spacing is required in such an operation.
The present invention . ~
~9~;'t)5 provideSa gas discharge lamp which can decrease an operation spacing for a connecting means to connect electrodes to an external power source, without pro-viding the electrodes one on each end side of that tube.
A gas discharge lamp according to this invention comprises a cylindrical-shaped tube having a discharge gas therein and through which light is passed, an inter-nal electrode provided at a tube end, and an external electrode provided outside of the tube along an axis of the tube, the internal and external electrodes respec-tively having a portion provided near the tube end for receiving energy to cause the discharge within the tube.
A gas discharge lamp apparatus according to another embodiment of this invention comprises a gas discharge lamp device including a cylindrical-shaped tube filled a discharge gas therein and through which light is passed, an internal electrode provided at a tube end, an external electrode provided outside of the tube along an axis of the tube, the internal and external electrodes respectively having a portion provided near the tube end, and a high frequency power source for applying to the portions a high frequency power to cause a gas discharge within the tube so that light is directed.
These and other features and advantages of this invention will become more apparent from the following 1;~9~
detailed description of exemplary embodiments as illustrated in the accompanying drawings in which:
Fig. 1 is a general view showing a gas discharge lamp according to a first embodiment of this invention;
Fig. 2 is a cross-sectional view, as taken along line I-I line, showing the lamp of Fig. 1;
Fig. 3 is an outer, perspective view showing the lamp of Fig. l;
Fig. 4 is a schematic view, generally showing a gas discharge lamp according to a second embodiment of this invention;
Fig. 5 is a cross-sectional view, as taken along line II-II, showing the lamp of Fig. 4; and Fig. 6 is a cross-sectional view, partly enlarged, showing a third embodiment of this invention gas discharge lamp of this invention.
A rare gas discharge lamp apparatus according to a first embodiment of this invention will be explained below by reference to Figs. 1 to 3.
In Fig. 1, discharge lamp 10 includes tube 12 of a cylindrical configuration with each end closed. Tube 12 is made of a light-transmissive quartz glass or a hard or soft glass and has, for example, internal diameter of below 2 mm, or external diameter of below 3 mm.
A rare gas of at least one kind selected from the group consisting of xenon, krypton, argon, neon, helium, etc. is sealed into tube 12 with xenon as a principal 1~9;~
component in which case a light output varies in pro-portion to the rare gas pressure level.
Within tube 12, internal electrode 14 made of, for example, nickel is provided at one end of the tube and serves as one of a pair of electrodes. An emitter mate-rial is coated on the surface of the internal electrode 1.2 mm in outer diameter to facilitate an electron emis-sion. Internal electrode 14 is sealingly mounted by a "pinch-sealing" method. Lead-in wire 16 which penetra-tes through the end wall of tube 12 in a gas-tight fashion is connected to internal electrode 14 and sealed within tube 12.
Fluorescent material layer 18 is formed on the inner surface of tube 12 such that the thickness of the film varies along the axis of the tube, for the reason set forth below.
That is, if the fluorescent material layer is uni-formly formed within tube 12 throughout the length of the tube, a luminance level becomes high at a position, for example, substantially two-thirds the whole length of the tube as viewed from internal electrode 14. In such a luminance distribution, the luminance level is decreased frGm the aforementioned position toward the end of tube 12.
For this reason, the thickness of fluorescent material layer 18 is so set as to obtain a transmittance of 25 to 40~. That is, the thickness of fluorescent 1~937~
material layer 18 is decreased at the position sub-stantially two-thirds the whole length of the tube as viewed from internal electrode 14 so that the transmittance exceeds 40%. In this case the thickness of fluorescent material layer 18 is gradually increased toward the end of the tube.
External electrode 20 is intimately attached to the outer side portion of tube 12 and serves as the other electrode. That is, external electrode 20 is formed from end to end across the whole length of the tube, that is, in a direction in which lead-in wire 16 to internal electrode 14 extends, to provide a band of a substantially uniform width along the axis of the tube.
External electrode 20 is formed of an electroconductive coating film which is obtained by coating, for example, a copper/carbon blend paste on the surface portion of the tube and sintering it.
Light shielding film 22 is formed on the external surface of tube 12 with an opening, such as slit 24, formed opposite to band-like external electrode 20 to allow passage of a predetermined quantity of light.
Stated in more detail, light shielding film 22 is formed over the whole surface of tube 12 except for slit 24, that is, over the outer tube surface including the outer surface of external electrode 20, with the width of slit 24 formed substantially uniformly across the whole length of the tube.
1~37~iS
In tube 12, first receiving end film 14a is formed on the outer surface portion of that tube end portion with internal electrode 14 sealed within the tube, that is, on the outer surface of light shielding film 22.
First receiving end film 14a is formed of an electrocon-ductive paste, such as silver--epoxy resin. First receiving end film 14a is connected to lead-in wire 16 which is connected to internal electrode 14.
Second receiving end film 20a is formed on the outer surface of tube 12 in an axially spaced-apart relation to first receiving end film 14a. Second receiving end film 20a is also formed of an electro-conductive paste, such as silver-epoxy resin and circum-ferentially so provided in the axially spaced-apart relation to first receiving end film 14a as to have a predetermined width. Second receiving end film 20a is formed on the outer surface of light shielding film 22, not on slit 24, and connected to external electrode 20.
Internal electrode 14 and external electrode 20 are connected to high frequency power source 28 through first receiving end film 14a and second receiving end film 20a and directly and through current-limiting capa-citor 26, respectively. High frequency power source 28 is comprised of inverter circuit 30, frequency generat-ing section 40 and power source 50.
Inverter circuit 30 is of such a push-pull type that transformer 32 has its primary winding connected to 1~9~'7~5 the collectors of switching transistors 34a and 34b and its secondary winding connected to discharge lamp 10.
Switching transistors 34a and 34b have their emitters connected to each other with a common junction coupled to a negative terminal (-) of variable D.C. power source 50 in the power source and their base-to-emitter circuits connected to a series circuit of resistors 36a and 36b.
Switching transistors 34a and 34b have their bases connected to I.C. 42 (e.g. TL494, Texas Instruments Inc) which, together with variable capacitor 44 and variable resistor 46, provides a frequency generating circuit.
Variable capacitor 44 and variable resistor 46 are grounded.
I.C. 42 is connected to both the terminals of D.C.
power source 50 to supply the voltage of D.C. power sup-ply 50. D.C. power source 50 has its positive terminal (+) connected to a predetermined location on the primary winding side of transformer 32 through coke coil 38.
In the gas discharge lamp, a high frequency power is supplied from D.C. power source 50 through first and second receiving ends 14a and 20a and through push-pull inverter 30 to internal electrode 14 and external electrode 20. At this time, the frequency employed is set to a proper value (20 to 45 KHz in this embodiment) by frequency generating section 40 comprised of I.C. 42, variable capacitor 44 and variable resistor 46.
3~ii g When current is supplied to internal electrode 14 and external electrode 20, the direct current is con-verted to an alternating current with the aforemen-tioned proper frequency through push-pull inverter 30.
A glow discharge corresponding to a lamp current of below 20 mA occurs across internal electrode 14 and external electrode 20 within tube 12 with the use of the aforementioned high frequency current. As a result of such glow discharge, fluorescent material layer 18 is excited by a resonance line of the rare gas within tube 12 to produce visible light. The visible light is emitted as a narrow beam pattern to the outside of tube 12 through slit 24.
Upon the occurrence of the aforementioned glow discharge the current density is decreased at a location remote from internal electrode 14 and external electrode 20. Since, however, fluorescent material layer 18 is so set as to obtain a transmittance of 25 to 40~ as already set out above, the luminance level is increased in a location remote from the aforementioned electrodes.
Even in the location nearer to internal electrode 14 and external electrode 20 the thickness of fluorescent material layer 18 is likewise so set as to obtain a transmittance of 25 to 40% and, even if electrons coming from internal electrode 14 never have a distance adequate to be accelerated, the luminance level is increased.
Furthermore, at the location substantially 1~3~6S
two-thirds the whole distance of tube 12 as viewed from internal electrode 14 the thickness of fluorescent material layer 18 is so set as to obtain a transmittance of over 40% and the luminance level is decreased at that location.
As a result, the luminance level is relatively increased at each end portion of tube 12 and decreased at the location substantially two-thirds the whole length of tube 12 as viewed from internal electrode 14.
By so doing, the luminance distribution tends to be made uniform as a whole within tube 12.
According to this invention, since the terminal or lead-in wire (the connecting means as the receiving end) of the internal electrode sealed within the tube and that of the external electrode extend from the same end of the tube, the lamp of this invention can reduce the operation spacing of said connecting means to one half that required in the conventional lamp.
From this it follows that light external emitted from tube 12 is restricted to only a light beam which is transmitted through slit 24. For this reason, the illu-mination light is directional in nature and is oriented only in the direction in which slit 24 is formed. Since the width of slit 24 can be made smaller than the diameter of tube 12, the illumination light can be transmitted, as a very narrow beam, through slit 24.
The outline of the illumination light becomes much lZ93765 sharper relative to the background becomes of the illu-mination of the light only through slit 24.
In the case of cylindrical-shaped discharge lamp 10, external electrode 20 is formed up to the end of tube 12 and thus the emission length of discharge lamp 10 corresponds to a distance from internal electrode 14 to the end of tube 12, offering a longer effective emission length. This means that it is not necessary to increase the length of the tube per se.
In discharge lamp 10, if the aforementioned high frequency power is adequately high, leakage current tends to flow b ~ween external electrode 20 and a dis-charge space wi/thin tube 12, allowing the capacitor's function to adequately reach the end of the tube. If, on the other hand, the aforementioned frequency power becomes lower, then the light emission length becomes shorter due to the failure of the capacitor's function to reach the end of the tube. It is therefore, pos-sible to freely vary the light emission length if the aforementioned frequency power is made variable.
Where, for example, the voltage of variable D.C.
power source 50 is varied or where the capacitance or resistance of variable capacitor 44 or variable resistor 46, respectively, in the frequency generating circuit is varied to cause a variation in frequency involved, then the aforementioned high frequency power varies in either case, causing a variation in a flow of leakage current 1;~93~6S
between externa] electrode 20 and the discharge space within tube 12. Therefore, the capacitor's function and thus the light emission length vary.
A rare gas discharge lamp according to a second embodiment of this invention will be explained below by reference to Figs. 4 and 5 jointly.
In Figs. 4 and 5, the internal arrangement of dis-charge lamp 10' is the same as the first embodiment.
That is, discharge lamp 10' includes tube 12 having fluorescent material layer 18 formed in the inner sur-face thereof. The thickness of fluorescent material layer 18 varies along the axis of tube 12 for the same reason as set forth in connection with the aforemen-tioned first embodiment. Further explanation is, there-fore, omitted.
The second embodiment is the same as the afore-mentioned embodiment with respect to the constituents of rare gas sealed within tube 12, gas pressure, internal electrode 14 provided within the tube at one end of the tube and lead-in wire 16.
External electrode 20' is formed on the whole outer surface of tube 12 except for slit 24 formed along the axis of tube 12. External electrode 20' is made of a light shielding material, such as carbon, and that outer surface portion of the tube not covered by external electrode 20', that is to say, slit 24' provides an opening through which light is emitted.
1~3~i5 Internal electrode 14 and external electrode 20' are connected to high frequency power source 28 directly and through current-limiting capacitor 26, respectively.
High frequency power source 28 is comprised of push-pull inverter 30, frequency generating section 40 and power source 50. That is, high frequency power source 28 is the same as that of the aforementioned embodiment.
Further explanation is, therefore, omitted.
In the gas discharge lamp, a high frequency power is supplied from D.C. power source 50 through push-pull inverter 30 to internal electrode 14 and external electrode 20'. Upon the supply of current to internal electrode 14 and external electrode 20' a glow discharge corresponding to a lamp current of below 20 mA is pro-duced across internal electrode and external electrode 20'. As a result, fluorescent material layer 18 is excited by a resonance line of a rare gas within tube 12 to produce visible light. The visible light is exter-nally emitted from within the tube through slit 24'.
In the second embodiment, the lead-in wires are also provided in the same direction of the tube, per-mitting the spacing of the connecting means to be halved as in the first embodiment when compared with the con-ventional lamp, and external electrode 20' covering the outer surface of tube 12 serves also as a light shield-ing film, ensuring a simpler structure than in the case where the light shielding film and external electrode 7~iS
are formed in separate steps. It is also easier to form the light shielding film.
The light emitting from within tube 12 is restricted only to light which has been transmitted through slit 24'. The illumination light is directional in nature, that is, is oriented only in the direction in which slit 24' is formed. Since the width of slit 24' is smaller than the diameter of tube 12, the illumina-tion light is emitted as a very narrow light beam through slit 24'.
The aforementioned gas discharge lamp is of such a type that a rare gas only is used. This rare gas discharge lamp utilizes the negative glow section of the glow discharge, offering such an advantage that the light output is not temperture-dependent.
The aforementioned gas discharge lamp does not need to be restricted only to the glow discharge and may be applied to an arc discharge in which case the inter-nal electrode is partially thickened so that a hot cathode is inserted therein.
The material to be sealed within the tube is not restricted only to the rare gas and this invention can equally be used as a low mercury vapor pressure discharge lamp. In a practical lamp using Hg sealed therein, for example, a very small amount of Hg of about 0.1 mg may be sealed at an argon pressure of 3 Torrs within the same tube as the rare gas discharge lamp.
1;~93~5 The fluorescent material layer is not necessarily required, because a special gas for emitting visible light may be sealed within the gas discharge lamp. For example, argon, neon and helium emit pink, orange and red purple color visible light, respectively. Further-more, a low mercury vapor pressure discharge lamp pro-duces visible light as an ultraviolet lamp of a narrow beam pattern source.
Fig. 6 shows another variant of a combination of internal and external electrodes and external power source of a third embodiment with one end portion shown enlarged. Tube 12 has fluorescent material layer 18 in the inner surface thereof and external electrode 20 on the outer surface portion thereof. External electrode 20 is obtained by bonding, for example, carbon phenol or silver-epoxy resin on the outer surface of tube 12 in a band-like fashion in the axial direction of the tube and sintering it. In this case, electrode 20 has a predeter-mined width along substantially the whole length of the tube. The resultant structure is covered by light shielding film 22 except at a location where slit 24 is formed. External electrode 20 is connected at one end to lead-in wire 20c in the axial direction of the tube.
Lead-in wire 20c is comprised of a covered cord and has its inner conductor jointed by soldering or silver-epoxy resin to one end of external electrode 20 at the loca-tion of connection portion 20b.
1~93~65 Recess 60 is formed as a mode at that location of tube 12 where lead-in wire 20c is taken out. Recess 60 provided a circumferentially continued groove, but it may be formed as one circumferential portion only.
In tube 12, insulating shrinkable tube 62 is fitted over recess 60 and connection portion 20b between exter-nal electrode 20 and lead-in wire 20c. Shrinkable tube is of a heat shrinkable type, such as vinylchloride or polyester, and intimately fitted over the base portion of the tube, that is, over connection portion 20b and lead-in wire 20c. In this way, connection portion 20b between external electrode 20 and lead-in wire 20c, as well as recess 60, are covered by shrinkable tube 62.
On the other hand, internal electrode 14 is sealed within the tube and brought out of the tube through lead-in wire 16.
In this embodiment, the other component parts, as well as the operation, are the same as in the aforemen-tioned first and second embodiments and any further explanation is, therefore, omitted.
In the third embodiment, a connection space at the receiving end can be reduced to one half that required in the conventional lamp. Since the base portion of lead-in wire 20c are firmly attached to tube 12 by shrinkable tube 62, even if any displacement of lead-in wire 20c relative to tube 12 occurs, for example, in a direction as indicated by an arrow in Fig. 6, it never propagates 1~937~iS
over connection portion 20b and thus no stress is pro-duced in connection section 20b, thus preventing a breakage of lead-in wire 20c.
Since shrinkable tube 62 is engaged with recess 60 at the end portion of tube 12, there is no possibility that is will slip out of tube 12.
Claims (22)
1. A gas discharge lamp comprising: an elongated tubular envelope containing only a rare gas and having a fluorescent material layer coated on the interior surface thereof; an internal electrode mounted within said envelope so as to be sealed therewithin; an external electrode formed on the exterior surface of said envelope and extending along the length of said envelope, the width of said external electrode being smaller than the internal diameter of said envelope;
shielding means attached to the exterior surface of said envelope so as to extend over the external electrode and substantially the entire exterior surface of said envelope;
and a narrow aperture defined on a side envelope opposite a side on which said external electrode is formed so as to be diametrically opposed to said external electrode, the width of said aperture being less than the internal diameter of said envelope.
shielding means attached to the exterior surface of said envelope so as to extend over the external electrode and substantially the entire exterior surface of said envelope;
and a narrow aperture defined on a side envelope opposite a side on which said external electrode is formed so as to be diametrically opposed to said external electrode, the width of said aperture being less than the internal diameter of said envelope.
2. A gas discharge lamp according to claim 1, wherein said rare gas is selected from the group consisting of xenon, krypton, argon, neon, and helium.
3. A gas discharge lamp according to claim 2, wherein said rare gas is principally comprised of xenon and said tube has a fluorescent material layer formed on the inner surface thereof.
4. A gas discharge lamp according to claim 3, wherein said rare gas is so sealed within said tube as to have a gas pressure of 30 to 160 Torrs.
5. A gas discharge lamp according to claim 4 wherein said tube has inner and outer diameters of below 2 mm and below 3 mm, respectively.
6. A gas discharge lamp according to claim 3 wherein said fluorescent material layer is so formed as to have a varying thickness in an axial direction of said tube.
7. A gas discharge lamp according to claim 1, wherein said tube includes light shielding means for shielding light except at a location where a slit is formed, said slit being so formed as to have a predetermined width and adapted to radiate light therethrough produced due to a discharge developed along an axial direction of the tube.
8. A gas discharge lamp according to claim 7 wherein said external electrode is so formed on the outer surface of said tube that it is located at least opposite to said slit across said tube.
9. A gas discharge lamp according to claim 7 wherein said external electrode is formed on the outer surface of said tube such that it also serves as said light shielding film means.
10. A gas discharge lamp according to claim 1, wherein said internal and external electrodes have terminals or lead-in wires.
11. A gas discharge lamp comprising: an elongated tubular envelope containing only a discharge rare gas and having a fluorescent material layer coated on the inside thereof; and internal electrode sealed in said envelope; and external electrode formed on the exterior of said envelope and extending along the length of said envelope, the width of said external electrode being smaller than the internal diameter of said envelope; shielding means attached to the exterior of said envelope, said shielding means extending over the exterior of said envelope, and having a narrow aperture extending along substantially the whole length of said envelope, said narrow aperture being positioned opposite said external electrode, the width of said aperture being smaller than the internal diameter of said envelope; and a high-frequency power source for supplying said internal electrode and said external electrode with highfrequency power to cause gas discharge within said envelope, thereby emitting light outward through said narrow aperture.
12. A gas discharge lamp apparatus according to claim 11, wherein said discharge gas is selected from the group consisting of xenon, krypton, argon, neon, and helium.
13. A gas discharge lamp apparatus according to claim 12, wherein said discharge gas is principally comprised of xenon and said tube has a fluorescent material layer formed on the inner surface thereof.
14. A gas discharge lamp according to claim 13, wherein said discharge gas is so sealed within said tube as to have a gas pressure of 30 to 160 Torrs.
15. A gas discharge lamp apparatus according to claim 14, wherein said tube has inner and outer diameters of below 2 mm and below 3 mm, respectively.
16. A gas discharge lamp apparatus according to claim 14, wherein said fluorescent material layer is so formed as to have a varying thickness in an axial direction of said tube.
17. A gas discharge lamp apparatus according to claim 11, wherein said tube has light shielding means for shielding light except at a location where a slit is formed, said slit being so formed as to have a predetermined width and adapted to radiate light therethrough produced due to a discharge developed along an axial direction of the tube.
18. A gas discharge lamp apparatus according to claim 11, wherein said external electrode is so formed on the outer surface of said tube that it is located at least opposite to said slit across said tube.
19. A gas discharge lamp apparatus according to claim 17, wherein said external electrode is formed on the outer surface of said tube such that it also serves as said light shielding means.
20. A gas discharge lamp apparatus according to claim 11, wherein said internal and external electrodes have terminal or lead-in wires.
21. A gas discharge lamp apparatus according to claim 11, wherein the high frequency power source is 20 to 45 KHz.
22. A gas discharge lamp apparatus according to claim 12, wherein a discharge length can be varied by the voltage or frequency of a high frequency power applied across said internal and external electrodes.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP166020/86 | 1986-07-15 | ||
| JP16602086 | 1986-07-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1293765C true CA1293765C (en) | 1991-12-31 |
Family
ID=15823429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000542098A Expired - Lifetime CA1293765C (en) | 1986-07-15 | 1987-07-13 | Rare gas discharge lamp with an external electrode |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS63146343A (en) |
| KR (1) | KR910002136B1 (en) |
| CA (1) | CA1293765C (en) |
| DE (1) | DE3723435A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5013966A (en) * | 1988-02-17 | 1991-05-07 | Mitsubishi Denki Kabushiki Kaisha | Discharge lamp with external electrodes |
| JP2655196B2 (en) * | 1990-03-28 | 1997-09-17 | 東芝ライテック株式会社 | Low pressure discharge lamp and display device using the same |
| JPH06181050A (en) * | 1993-06-28 | 1994-06-28 | Toshiba Lighting & Technol Corp | Noble gas discharge lamp device |
| JPH06163005A (en) * | 1993-06-28 | 1994-06-10 | Toshiba Lighting & Technol Corp | Rare gas discharge lamp |
| DE19548003A1 (en) * | 1995-12-21 | 1997-06-26 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Circuit arrangement for generating pulse voltage sequences, in particular for the operation of dielectrically impeded discharges |
| DE19844921A1 (en) * | 1998-09-30 | 2000-04-13 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Flat lighting device has optical system that influences spatial light distribution of light to be coupled into plate to have at least one maximum in defined angular range wrt. optical axis |
| JP3448534B2 (en) * | 2000-02-18 | 2003-09-22 | 三菱電機株式会社 | Contact type image sensor unit |
| KR100416644B1 (en) * | 2001-03-27 | 2004-02-05 | 주식회사 엘지화학 | One Artificial Marble Panel with the Two Patterns and the Method of Manufacturing therof |
| JP4557924B2 (en) * | 2006-06-06 | 2010-10-06 | 株式会社スペースアート | Discharge lamp for emitting pseudo flame and lighting device for decoration using the discharge lamp for emitting pseudo flame |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE374670A (en) * | 1929-11-07 | |||
| US3067351A (en) * | 1960-01-04 | 1962-12-04 | Sylvania Electric Prod | Aperture fluorescent lamp |
| DE6753632U (en) * | 1968-09-19 | 1969-05-29 | Philips Nv | LOW PRESSURE DISCHARGE LAMP WITH A WALL NOT CLOSING THE DISCHARGE SPACE, THAT U.A. CONSISTS OF A BEAM. |
| US4471350A (en) * | 1980-09-12 | 1984-09-11 | Chow Shing C | Display device using a discharge lamp |
| JPS5834560A (en) * | 1981-08-21 | 1983-03-01 | 周 成祥 | Discharge lamp display unit |
| JPS6163760U (en) * | 1984-09-29 | 1986-04-30 | ||
| JPS6195052U (en) * | 1984-11-27 | 1986-06-19 |
-
1987
- 1987-07-13 CA CA000542098A patent/CA1293765C/en not_active Expired - Lifetime
- 1987-07-13 JP JP62174112A patent/JPS63146343A/en active Pending
- 1987-07-15 DE DE19873723435 patent/DE3723435A1/en active Granted
- 1987-07-15 KR KR1019870007653A patent/KR910002136B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| KR880002224A (en) | 1988-04-29 |
| DE3723435C2 (en) | 1991-09-05 |
| KR910002136B1 (en) | 1991-04-04 |
| DE3723435A1 (en) | 1988-01-21 |
| JPS63146343A (en) | 1988-06-18 |
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