JP2004031229A - Discharge lamp and discharge lamp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp device of which manufacture is facilitated and lamp efficiency is improved. <P>SOLUTION: A dielectric barrier discharge is carried out in a discharge space 19 between electrodes 22 via an inner glass tube 15 and a positive column is generated, and an ultraviolet ray is radiated. A phosphor layer 21 is excited by the ultraviolet ray, converted into a visible ray, and emits light. Because the tip end of the electrode 22 has one part extended into a part of a dome part 17 of the tip end side of a fluorescent lamp 2, the positive column by discharge is also generated in the tip-end direction of the fluorescent lamp 2, and also the tip end side of the fluorescent lamp 2 is surely irradiated. Because the electrode 22 discharges in the discharge space 19 via the interior glass tube 15, dielectric breakdown voltage of the interior glass tube 15 is high and a voltage to be applied between the electrodes 22 can be made high because distance between the electrodes 22 can be made longer. Because a gas pressure of xenon gas in the discharge space 19 can be made higher, the positive column can be formed in large amount and amount of light emission increases, and the lamp efficiency is improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a discharge lamp and a discharge lamp device having electrodes outside a discharge space.
[0002]
[Prior art]
Conventionally, as this main discharge lamp, for example, a configuration described in JP-A-2001-297733 is known. Japanese Patent Application Laid-Open No. 2001-297733 discloses that a cylindrical outer glass tube whose one end side bulges in a dome shape has an inner diameter smaller than that of an outer glass tube whose one end side similarly bulges in a dome shape. To form a so-called double-cylindrical bulb-shaped discharge vessel, and fusion-bond these outer and inner glass tubes at the other end to form an outer glass tube and an inner glass tube. A discharge space is formed between the discharge spaces, and a xenon (Xe) gas is sealed in the discharge space. Further, a pair of electrodes are formed on the discharge space side of the inner glass tube, a dielectric layer is formed on the surface of these electrodes, and a phosphor layer is formed on the surface of the dielectric layer.
[0003]
Then, a voltage is applied between the electrodes, a discharge is caused between the electrodes in the discharge space through the dielectric layer, and ultraviolet light is emitted. The ultraviolet light excites the phosphor layer to convert it into visible light, thereby emitting light. .
[0004]
[Problems to be solved by the invention]
Further, in order to improve the lamp efficiency of the discharge lamp, a positive column may be formed between the electrodes by increasing the distance between the electrodes. However, if the distance between the electrodes is increased, the starting voltage at the time of discharge increases.
[0005]
However, it is difficult to increase the thickness of the dielectric layer to several hundreds μm or more, so that the dielectric breakdown voltage cannot be increased. If a high voltage is applied in this state, the dielectric layer is broken and the discharge lamp does not light. There is a risk.
[0006]
In addition, since the electrodes are formed on the discharge space side of the discharge vessel, there is a problem that manufacturing is complicated.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a discharge lamp and a discharge lamp device that facilitate manufacture and improve lamp efficiency.
[0008]
[Means for Solving the Problems]
The discharge lamp according to claim 1 is a discharge vessel in which an air-tight discharge space is formed by connecting the other ends of a pair of pipes having different diameters, one end of which is closed and arranged in the axial direction. A pair of electrodes provided on the surface of the tube located inside the discharge vessel opposite to the discharge space; a discharge gas filled in the discharge space; and a discharge space on the surface of the discharge vessel on the discharge space side. And a phosphor layer provided inside the discharge vessel. A voltage is applied between electrodes provided on a surface opposite to a discharge space of the tube located inside the discharge vessel, and a tube located inside the discharge vessel. By discharging through the body, ultraviolet rays are radiated into the discharge space of the electrode tube, which excites the phosphor layer and irradiates the ultraviolet rays, and the electrodes are on the opposite side of the discharge vessel to the discharge space. Forming on the surface facilitates the manufacturing process and Ri insulating withstand voltage can be improved, for example by the applied voltage increased to increase the gas pressure of the discharge gas in the discharge space, the lamp efficiency is improved.
[0009]
The discharge lamp according to claim 2 is the discharge lamp according to claim 1, wherein the electrodes are provided along the axial direction of the discharge vessel, and by arranging the electrodes along the axial direction of the discharge vessel, Since each electrode can be located near the other end of the tube of the discharge vessel, wiring to the electrodes is facilitated.
[0010]
According to a third aspect of the present invention, there is provided the discharge lamp according to the first aspect, wherein the electrode is provided along a radial direction of the discharge vessel, and generally has an allowance in the radial direction. Since the number is large, the distance between the electrodes can be increased, and the applied voltage between the electrodes can be increased, so that the lamp efficiency is easily increased.
[0011]
According to a fourth aspect of the present invention, there is provided the discharge lamp according to any one of the first to third aspects, wherein the visible light transmittance of the phosphor layer is smaller than that provided in a tube located outside the discharge vessel. The one provided in the tube is higher, and the phosphor layer of the inner tube reduces the ultraviolet and visible light that penetrates inside, improves the conversion efficiency of converting ultraviolet light to visible light, and transmits visible light. Reflection without reflection improves light use efficiency, and the outer tube reduces visible light absorbed by the phosphor layer to improve light use efficiency.
[0012]
A discharge lamp device according to claim 5, a discharge lamp according to any one of claims 1 to 4, a lighting device for lighting the discharge lamp, a cover body to which the discharge lamp is attached and which houses the lighting device; It is provided with a base provided on the body to supply power to the lighting device, and has respective functions.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a bulb-type fluorescent lamp device according to an embodiment of the discharge lamp device of the present invention will be described with reference to the drawings.
[0014]
1 is a longitudinal sectional view showing a fluorescent lamp, FIG. 2 is a transverse sectional view, and FIG. 3 is a side view showing a bulb-shaped fluorescent lamp.
[0015]
As shown in FIG. 3, a bulb-shaped fluorescent lamp 1 which is this discharge lamp device has a fluorescent lamp 2 as a dome-shaped discharge lamp having a substantially hemispherical tip, and a fluorescent lamp 2 at a base end side thereof. A cover body 3 is attached, and the fluorescent lamp 2 and the cover body 3 form a substantially bulb shape. A lighting device 4 including a boost chopper circuit for lighting the fluorescent lamp 2 and an inverter circuit is accommodated in the cover body 3. Further, an Edison type base 5 such as an E26 type is attached to the base end of the cover body 3, and external power is supplied to the lighting device 4 by inserting the base 5 into a lamp socket (not shown) or the like.
[0016]
Further, as shown in FIG. 1, the fluorescent lamp 2 has a discharge vessel 11 in the form of a so-called double cylindrical bulb made of lead-containing glass as a dielectric. The discharge vessel 11 has an outer glass tube 12 which is a cylindrical tube having a length of 100 mm, a diameter of 60 mm, and a thickness of 500 μm. The glass tube 12 has a cylindrical portion 13 formed therein. One end side of the cylindrical portion 13 is closed by a dome portion 14 bulging into a substantially hemispherical dome shape, and the inside of the outer glass tube 12 is smaller in diameter and length than the outer glass tube 12. An inner glass tube 15 as a short, 85 mm long, 30 mm diameter, 500 μm thick cylindrical tube is inserted coaxially with the outer glass tube 12, and the inner glass tube 15 is also inserted into the outer glass tube 12. Similarly, a cylindrical portion 16 is formed, and one end of the cylindrical portion 16 is closed by a dome portion 17 bulging into a substantially hemispherical dome shape. The outer glass tube 12 and the inner glass tube 15 are each melt-connected at the other end and closed by a fusion connection portion 18 to form an airtight discharge space 19.
[0017]
Xenon (Xe) gas is filled and sealed in the discharge space 19 at a pressure of 10 kPa.
[0018]
Further, on the inner surface of the discharge space 19 side, converts the ultraviolet rays excitation into visible light, for example, emits light by excimer emission wavelength 172nm xenon, specifically _BAM, LaPO 4: Ce, Tb and _Y 2 _O 3: A phosphor layer 21 of Eu or the like is formed by coating. In the phosphor layer 21, the inner glass tube 15 is formed thicker than the outer glass tube 12, that is, the visible light transmittance of the phosphor layer 21 is higher than that of the phosphor layer 21 provided in the outer glass tube 12. The phosphor layer 21 provided in the inner glass tube 15 is higher.
[0019]
Further, a pair of electrodes 22 having a width of 5 mm are opposed to a center side of the discharge vessel 11 opposite to the discharge space 19 of the inner glass tube 15 along an axial direction which is a longitudinal direction of the discharge vessel 11. These electrodes 22 and 22 are electrically connected to the lighting device 4. Note that the distal end side of the discharge vessel 11 of the electrode 22 is extended to the dome portion 17 as close to each other as there is no problem in insulation.
[0020]
Next, the lighting operation of the above embodiment will be described.
[0021]
Then, a voltage of 80 kHz, a pulse width of 1 μs, and a pulse voltage of 2 kV is applied between the lighting device 4 and the electrodes 22 and 22 to generate a discharge space between the electrodes 22 and 22 via the inner glass tube 15 which is a dielectric. At 19, for example, a discharge such as a dielectric barrier discharge is performed to generate a positive column, which emits ultraviolet rays mainly having a wavelength of 172 nm. The ultraviolet rays excite the phosphor layer 21 to convert it into visible light, thereby emitting light. In addition, since the tips of the electrodes 22 and 22 partially extend to the dome portion 17 on the tip side of the fluorescent lamp 2, a positive column due to discharge also occurs in the tip direction of the fluorescent lamp 2, The front end of the fluorescent lamp 2 is also reliably irradiated.
[0022]
Further, by increasing the thickness of the phosphor layer 21 of the inner glass tube 15, it is possible to prevent the ultraviolet light and the visible light from being transmitted in the direction of the inner glass tube 15, reflect the visible light, and efficiently make the ultraviolet light visible. By converting the light into light and making the phosphor layer 21 of the outer glass tube 12 thinner, the absorption of visible light by the phosphor layer 21 of the outer glass tube 12 is suppressed, and the visible light is efficiently transmitted to the outside. Irradiate.
[0023]
According to the above embodiment, the electrodes 22, 22 are discharged in the discharge space 19 via the inner glass tube 15, so that the dielectric strength of the inner glass tube 15 is high and the distance between the electrodes 22, 22 is long. Therefore, the voltage applied between the electrodes 22 and 22 can be increased, and the gas pressure of xenon gas in the discharge space 19 can be increased. Therefore, the radiation of ultraviolet light having a wavelength of 172 nm due to the excimer radiation of xenon increases, and the voltage decreases. Since more positive columns can be formed than in the conventional case where only discharge is performed on the electrode surface, the amount of light emission increases, and the lamp efficiency improves.
[0024]
Further, since the electrodes 22 and 22 are located on the center side of the inner glass tube 15, even if ozone is generated by the discharge between the electrodes 22 and 22, the space surrounded by the inner glass tube 15 and the cover body 3. Therefore, ozone hardly flows out to the outside and is not easily affected by ozone.
[0025]
Further, even if visible light is irradiated in the direction of the inner glass tube 15, the loss is lost. Therefore, by increasing the thickness of the phosphor layer 21 of the inner glass tube 15, ultraviolet light and visible light are directed toward the inner glass tube 15. To efficiently convert the ultraviolet light into visible light while reflecting the visible light toward the outer glass tube 12, and by thinning the phosphor layer 21 of the outer glass tube 12, The absorption of the visible light by the phosphor layer 21 of the outer glass tube 12 is suppressed, and the visible light is efficiently emitted to the outside.
[0026]
Further, the electrodes 22 and 22 are formed on the inner glass tube 15 on the side opposite to the discharge space 19 to facilitate manufacture, and the electrodes 22 and 22 are formed along the axial direction of the inner glass tube 15 to form the electrodes. Since the other ends of the electrodes 22, 22 are partially located on the other end side of the discharge vessel 11, electrical wiring can be easily performed without complicated insulation.
[0027]
Next, another embodiment will be described with reference to FIG.
[0028]
FIG. 4 is a longitudinal sectional view showing a fluorescent lamp according to another embodiment, and has basically the same configuration as the bulb-type fluorescent lamp shown in FIGS.
[0029]
The fluorescent lamp 2 shown in FIG. 4 has the electrodes 23 and 24 provided along the radial direction in the direction intersecting the axial direction. The electrode 23 is located on the inner glass tube 15 near the other end of the fluorescent lamp 2. The electrode 24 is formed in an annular shape on the opposite side to the discharge space 19 on the other end side, and the electrode 24 is formed in a hemispherical dome shape on the opposite side to the discharge space 19 of the dome portion 17 that is separated from the electrode 23 by an insulation distance or more. ing.
[0030]
The operation and effect are the same as those of the bulb-type fluorescent lamp 1 shown in FIGS. 1 to 3, but the respective electrodes 23 and 24 are formed along the radial direction intersecting the axial direction of the inner glass tube 15. By doing so, a relatively long insulating distance can be maintained in the axial direction, so that the distance between the electrodes 23 and 24 can be increased and a higher voltage can be applied.
[0031]
In addition, since the electrode 24 is formed on the center side of the dome portion 17 along the shape of the dome portion 17, a positive column can also be formed on the dome portion 17, and light can be emitted from the dome portion 17, so that the tip side of the fluorescent lamp 2 It can irradiate light greatly.
[0032]
In the fluorescent lamp 2 shown in FIG. 4, the shape of the electrode 24 is adjusted to the shape of the dome portion 17.
[0033]
Note that, in the above-described embodiment, a description has been given of a pair of electrodes 22, 22, 23, and 24. The same effect can be obtained by forming a pair by combining a plurality of electrodes.
[0034]
In addition, although all of the embodiments have been described with the bulb-type fluorescent lamp, the same effect can be obtained by using the fluorescent lamp as a straight tube type fluorescent lamp.
[0035]
【The invention's effect】
According to the discharge lamp of the first aspect, a voltage is applied between electrodes provided on the surface of the tube located inside the discharge vessel opposite to the discharge space, and the tube located inside the discharge vessel is moved. UV light is radiated into the discharge space of the electrode tube by irradiating the phosphor layer with the UV light to irradiate the UV light, and the electrode is disposed on the surface of the discharge vessel opposite to the discharge space. The formation can facilitate the manufacturing process, and the tube can also improve the dielectric strength voltage. For example, by increasing the applied voltage to increase the gas pressure of the discharge gas in the discharge space, the lamp efficiency can be improved.
[0036]
According to the discharge lamp of the second aspect, in addition to the discharge lamp of the first aspect, by positioning the electrodes along the axial direction of the discharge vessel, each electrode is positioned near the other end of the tube of the discharge vessel. , Wiring to the electrodes can be facilitated.
[0037]
According to the discharge lamp of the third aspect, in addition to the discharge lamp of the first aspect, generally, there is often a margin in the radial direction, so that the distance between the electrodes can be increased, and the application between the electrodes can be increased. Since the voltage can be increased, the lamp efficiency can be increased.
[0038]
According to the discharge lamp of the fourth aspect, in addition to the discharge lamp of any one of the first to third aspects, the phosphor layer of the inner tube reduces ultraviolet light and visible light transmitted to the inside to reduce ultraviolet light to visible light. The efficiency of the light is improved by reflecting the visible light without transmitting it, and the outer tube reduces the visible light absorbed by the phosphor layer to improve the light use efficiency. Can be improved.
[0039]
According to the discharge lamp device according to the fifth aspect, the discharge lamp device according to any one of the first to fourth aspects is provided, and each effect can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a fluorescent lamp according to one embodiment of a discharge lamp device of the present invention.
FIG. 2 is a cross-sectional view of the same.
FIG. 3 is a side view showing the same bulb-type fluorescent lamp.
FIG. 4 is a longitudinal sectional view showing a fluorescent lamp according to another embodiment of the present invention;
[Explanation of symbols]
REFERENCE SIGNS LIST 1 bulb-type fluorescent lamp as discharge lamp device 2 fluorescent lamp as discharge lamp 3 cover 4 lighting device 5 base 11 discharge vessel 12, 15 glass tube as tube 19 discharge space 21 phosphor layers 22, 23, 24 electrodes

Claims (5)

A discharge vessel in which one end is closed and an airtight discharge space is formed by connecting the other ends of a pair of tubes having different diameters arranged in the same axial direction;
A pair of electrodes provided on the surface of the tube located inside the discharge vessel opposite to the discharge space;
A discharge gas filled in the discharge space;
A phosphor layer disposed on the discharge space side surface of the discharge vessel;
A discharge lamp comprising: The discharge lamp according to claim 1, wherein the electrodes are provided along an axial direction of the discharge vessel. The discharge lamp according to claim 1, wherein the electrode is provided along a radial direction of the discharge vessel. 4. The phosphor layer according to claim 1, wherein the visible light transmittance of the phosphor layer provided on the inner tube is higher than that of the phosphor layer provided on the tube located outside the discharge vessel. The discharge lamp as described. A discharge lamp according to any one of claims 1 to 4;
A lighting device for lighting the discharge lamp;
A cover body on which the discharge lamp is mounted and which houses the lighting device;
A base provided on the cover body for supplying power to the lighting device;
A discharge lamp device comprising:

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