JP2010262875A - Rare gas discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rare gas discharge lamp capable of preventing that a light amount is reduced in the vicinity of a conductive material layer formed for starting despite a simple structure while securing starting performance in the rare gas discharge lamp equipped with an external electrode. <P>SOLUTION: In the rare gas discharge lamp which has a glass bulb 11 in which rare gas is sealed and one and other electrodes 13, 14 are formed on the outer face, and in which a first conductive material layer is integrally arranged over a region which is on the inner face of the glass bulb 11 and opposed to the one electrode 13, a region opposed to the other electrode, and a region opposed to these electrodes, in the region closer to the glass bulb 11 center side than the first conductive material layer 15 and opposing to either one or the other electrodes 13, 14 on the inner face of the glass bulb 11, a second conductive material layer 16 is arranged so as to be separated from the first conductive material layer 15. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rare gas discharge lamp.

Conventionally, a rare gas discharge lamp in which only a rare gas is enclosed in a straight tubular glass bulb and an electrode disposed on the outer surface of the glass bulb over the substantially entire length of a glass bulb made of a pair of conductive materials is a scanner. It is used as a light source for reading OA documents such as copying machines and facsimile machines.
In this rare gas discharge lamp, since the electrode is not provided inside the glass bulb, the electrode is not exposed to the discharge. Therefore, the rare gas discharge lamp has a long life with few failures caused by the deterioration of the electrode. Since only gas is used and mercury is not used as the luminescent species, the startability is good even under low temperature conditions. Recently, such rare gas discharge lamps are attracting attention for use as light sources for backlights of general illumination and liquid crystal display devices due to the above characteristics.

FIG. 8 is a perspective view of a rare gas discharge lamp according to the prior art.
In the figure, a rare gas discharge lamp 20 is provided with an elongated glass bulb 21 having optical transparency, and a rare gas containing xenon gas is enclosed therein and a phosphor layer (not shown) is formed. Yes. On the glass bulb 21, a pair of external electrodes 22, 23 extending in the length direction of the glass bulb 21 are disposed opposite to each other. A conductive material layer 24 is formed on the inner surface of the glass bulb 21 for startability.
The high frequency power supply 25 is connected to the external electrodes 22 and 23, and the lamp is lit by applying a high voltage. By applying the high frequency voltage, the rare gas discharge lamp 20 generates a discharge of xenon gas in the discharge space inside the glass bulb 21 sandwiched between the electrodes 22 and 23, and ultraviolet light generated by the discharge is applied to the inner surface of the glass bulb 21. The fluorescent material is excited and converted into visible light, and the visible light is emitted to the outside of the glass bulb 21 (see Patent Document 1 and Patent Document 2).

  The conductive material layer 24 is disposed by, for example, continuously forming a conductive material in a region facing both the one and the other external electrodes 22 and 23 on the inner peripheral surface of the glass bulb 21. is there. As described above, the conductive material layer 24 is continuously formed so as to face both the electrodes 22 and 23, whereby the startability of the lamp 20 can be improved.

However, in this rare gas discharge lamp, it is known that the end of the glass bulb becomes dark after the lamp is lit, as is known, for example, in Patent Document 3.
This phenomenon is recognized to occur in the vicinity of the conductive material layer formed across both electrodes regardless of the specifications of the rare gas discharge lamp, and tends to be darker as the electrode width is smaller. The cause of the darkening of the end portion is that the capacitive coupling is formed in the glass bulb layer between the conductive material layer and the external electrode provided for starting the lamp, and the electric power supplied during steady lighting of the lamp Is undesirably consumed, and it is considered that the discharge is insufficient only at the end in the length direction of the electrode.

  For such a problem, in the technique of Patent Document 3, by providing a dielectric layer on the inner surface of the glass bulb in the vicinity of the starting conductor so as to cover at least one external electrode in the circumferential direction, The ratio of the electric charge attracted by the conductive material layer is decreased, and the decrease in the discharge density at the end is suppressed.

JP 08-329903 A JP 2007-087898 A JP 2008-034211 A

  However, stably forming the dielectric layer inside the glass bulb has a problem that the workability is poor and the manufacturing process becomes complicated.

  In the light source for the general illumination and the backlight device as described above, a structure that emits light over the entire circumference of the glass bulb is required because the light source is taken out in any direction. For this purpose, it is desirable to reduce the width of the external electrode so that it does not hinder light emission. For this reason, the electrode width is required to be small, for example, 1 mm or less, preferably 0.5 mm. However, when the electrode width is reduced in this way, the dark part at the end of the glass bulb becomes more prominent, and the predetermined This causes a problem that the effective light emission length cannot be obtained. In order to deal with such a problem, it may be mentioned that the conductive material layer is not formed. However, the lamp starting reliability is impaired, and a problem arises that the starting voltage must be further increased. Therefore, it is not a fundamental solution.

  Therefore, the problem to be solved by the present invention is to secure a startability in a rare gas discharge lamp having an external electrode and to have a simple structure, but with a light quantity in the vicinity of the conductive material layer formed for the start. It is an object of the present invention to provide a rare gas discharge lamp that can prevent a decrease in the temperature.

The present invention has a glass bulb in which a rare gas is sealed and one and the other electrodes are formed on the outer surface along the longitudinal direction thereof, on the inner surface of the glass bulb, and opposed to the one electrode. In the rare gas discharge lamp in which the first conductive material layer is integrally disposed over the region, the region facing the other electrode, and the region facing between the electrodes,
In a region closer to the glass bulb center than the first conductive material layer and facing the one or other electrode on the inner surface of the glass bulb, the first conductive material layer is spaced apart from the first conductive material layer. Two conductive material layers are arranged.
The second conductive material layer may be made of carbon paste.

  According to the present invention, the light quantity is reduced in the vicinity of the conductive material layer formed for starting the glass bulb while ensuring startability in a rare gas discharge lamp having an external electrode, although having a simple structure. Therefore, the effective light emission length can be set to a desired length.

1 is a cross-sectional view in the tube axis direction of a rare gas discharge lamp according to a first embodiment of the present invention. It is arrow sectional drawing cut | disconnected by BB and CC in FIG. It is sectional drawing cut | disconnected by the surface which passes the 2nd electroconductive substance layer which concerns on other embodiment of this invention. It is sectional drawing cut | disconnected by the surface which passes the 2nd electroconductive substance layer which concerns on other embodiment of this invention. It is sectional drawing cut | disconnected by the surface which passes along the 2nd electroconductive substance layer which concerns on other embodiment of this invention. It is a luminance distribution figure of the lamps 1, 2, 3, 4, and 8 which concern on an Example and a comparative example. It is a luminance distribution figure of lamp | ramp 5, 6, 7, 8 which concerns on an Example and a comparative example. It is explanatory drawing explaining the noble gas discharge lamp which concerns on a prior art.

1A is a cross-sectional view of a rare gas discharge lamp cut along a plane including an electrode and a tube axis of a lamp according to a first embodiment of the present invention, and FIG. It is arrow sectional drawing cut | disconnected by line segment AA. 2A is a cross-sectional view taken along line BB in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line CC in FIG. 1A. is there.
As shown in FIG. 1, the external electrode type rare gas discharge lamp includes a straight tubular glass bulb 11 in which a rare gas is sealed, and on the outer surface of the glass bulb 11, the tube axis direction is parallel to each other. One external electrode 13 and the other external electrode 13 are formed. The external electrodes 13 and 14 are made of an aluminum foil cut to a predetermined width of 0.5 to 2 mm, for example, and are configured to be affixed to opposing positions on the outer surface of the glass bulb 11 with the central axis of the lamp interposed therebetween Is done. In addition to this configuration, for example, a conductive paste may be applied and screened by means such as screen printing.
Lead wires (not shown) are connected to the one and the other external electrodes 13 and 14, respectively, at an end region opposite to the shown side, and are connected to a high frequency power source (not shown).

As the rare gas sealed in the glass bulb 11, for example, xenon gas or a mixed gas of xenon and other rare gas can be exemplified, and the sealed amount is, for example, 22 kPa.
Inside the glass bulb 11, a phosphor layer 12 is formed over substantially the entire inner surface. The fluorescent material used has a property of being excited by ultraviolet light having a peak near a wavelength of 172 nm generated by discharge of xenon gas, and is used in the visible region when used in backlight or general illumination applications. Phosphors having the characteristic of emitting light, such as europium activated barium magnesium aluminate [BaMgAl ₁₀ O ₁₇ : Eu] (abbreviation: BAM) phosphor, terbium cerium activated lanthanum phosphate [La-P- O: Ce, Tb] (abbreviation: LAP) phosphor, europium-activated yttrium gadonium borate [(Y, Gd) BO ₃ : Eu ³⁺ ] (abbreviation: YGB) phosphor, and the like are used. Of course, in addition to this, an appropriate fluorescent material can be selected according to the light of the wavelength band to be used.

On the inner surface of the end portion of the glass bulb 11, a first conductive material layer 15 for starting the lamp is provided at the end portion on the non-connecting portion side of the lead wire as shown in FIG. It is formed continuously. In this example, the first conductive material layer 15 is on a portion where the phosphor layer 12 is not formed, but may be on the phosphor layer 12 or the like.
On the inner surface of the glass bulb 11, the first conductive material layer 15 is a region facing one external electrode 13, a region facing the other external electrode 14, and a non-electrode between the one and the other electrodes 13, 14. It is integrally formed so as to cover a region facing the forming portion. Thus, by providing the conductive material layer so as to connect the one electrode 13 and the other electrode 14, the glass bulb can be easily polarized after applying the starting voltage, and the dielectric breakdown voltage can be kept low. The technique related to the first conductive material layer 15 is the same as that of Patent Document 1, and it is possible to realize a rapid start of discharge with a dielectric interposed.

  The first conductive material layer 15 can be made of a conventionally known material and includes at least one of aluminum, silver, graphite, tin oxide, indium oxide, barium, nickel and the like. Or a mixture of them. Specifically, a so-called carbon paste produced by kneading graphite and frit glass is suitable.

Further, in the rare gas discharge lamp according to the present invention, the first conductive material layer 15 is closer to the center of the lamp, that is, the light emitting region side, and is electrically connected to the first conductive material layer 15. The second conductive material layer 16 is disposed at a spaced position. As shown in FIG. 2B, the second conductive material layer 16 faces only the external electrode 14 on one side and does not face the other external electrode 13. This is an indispensable requirement for making the function different from that of the first conductive material layer 15.
It should be noted that the second conductive material layer 16 may be formed so as to protrude from the non-formed portion of the electrode as long as it is disposed so as to face only the electrode on one side.

  As a material constituting the second conductive substance layer 16, the same kind of substance as the first conductive substance layer 15 can be used, that is, aluminum, silver, graphite, tin oxide, indium oxide, barium, It is a substance containing at least one kind of nickel or a mixture thereof. Specifically, a so-called carbon paste produced by kneading graphite and frit glass is suitable. Thus, when a nonmetallic conductive paste is used, it is possible to suppress the occurrence of sputtering during discharge.

Here, the operation of the rare gas discharge lamp according to the present invention will be described in detail.
When a starting voltage is applied to the external electrodes 13 and 14 of the lamp from a high-frequency power source (not shown), first, the wall of the glass bulb 11 between the first conductive material layer 15 and the external electrodes 13 and 14 serves as a capacitor. Since the first conductive material layer 15 functions and is integrally formed across the one and the other electrodes 13 and 14, the electrodes are capacitively coupled, and discharge is started quickly.
After the discharge is started, the first conductive material layer 15 becomes functionally unnecessary, but since the coupling cannot be broken structurally, a charge is induced due to the capacitive coupling. Since the two conductive material layers 16 are arranged to face one of the electrodes, the electric charge is collected in the vicinity of the second conductive material layer 16 to increase the discharge density. Is prevented from flowing out to the first conductive material layer 15 side. Here, since the second conductive material layer 16 is disposed so as to face only one of the electrodes, the second conductive material layer 16 does not form capacitive coupling. Therefore, the collected electric charge is contributed to the discharge without being undesirably consumed.
As a result, the discharge is surely performed in the vicinity of the second conductive material layer 16 of the glass bulb, and the radiation amount of the ultraviolet light generated by the discharge is increased, so that it is converted by the phosphor layer 12. The amount of light emitted can be increased.

  As described above, according to the rare gas discharge lamp according to the present invention, capacitive coupling occurs due to the presence of the first conductive material layer during steady lighting of the lamp, and discharge is reduced by attracting charges in the vicinity thereof. As a result, the amount of light emitted at the end can be increased without impairing the starting performance of the lamp. Become. And it becomes possible to form effective light emission length in the whole length direction of a noble gas discharge lamp.

Various modifications can be made in the present invention, which will be described below.
FIG. 3 is a cross-sectional view illustrating another embodiment of the present invention, and the configurations described above with reference to FIGS. The second conductive material layer 16 is provided on the inner surface of the glass bulb 11 in regions facing the one and the other electrodes 13 and 14, respectively. Without being connected to each other, they are spaced apart in the circumferential direction. In this example, the first conductive layer 15 and the second conductive material layer 16 are directly formed on the inner surface of the glass bulb 11 by partially removing the phosphor layer 12. .
It is also possible to form the second conductive material layer 16 for each of the one and the other external electrodes 13 and 14 as in this embodiment, and according to such a configuration, the first conductive material layer 16 can be further formed. The charge attracted to the conductive material layer side can be reduced, and the discharge density in the vicinity of the second conductive material layer 16 can be increased.

FIG. 4 is a diagram for explaining a further different embodiment, and the configurations described above with reference to FIGS. In this embodiment, the second conductive material layer 16 is formed on the inner surface of the glass bulb in a region facing each of the one and the other electrodes 13 and 14, and each second conductive material layer 16 is formed. In this example, the phosphor layer 12 is formed on 16.
Thus, even when the phosphor layer is formed on the second conductive material layer 16, the function of the second conductive material layer is not changed at all.

Still another embodiment will be described with reference to FIG. In addition, about the structure demonstrated previously in FIGS. 1-4, it shows with the same code | symbol and abbreviate | omits description. In this embodiment, the second conductive material layer 16 is formed on the inner surface of the glass bulb 11 facing the one and the other electrodes 13 and 14, and the second conductive material layer 16 is formed on the phosphor layer. 12 is an example in which a laminated state is formed on 12.
As described above, when the second conductive material layer 16 is disposed on the phosphor layer 12, the layer of the glass bulb 11 is interposed between the second conductive material layer 16 and the external electrodes 13 and 14. The two dielectrics of the phosphor layer 12 are interposed, but even in such a mode, the performance is not changed, and it can be used without any problem. According to this embodiment, when forming the 1st or 2nd electroconductive substance layers 15 and 16, the operation | work which removes the fluorescent substance layer 12 apply | coated to the edge part becomes unnecessary, and productivity is improved further. be able to.

  As described above, the present invention has been described based on the embodiment as described above. However, the present invention can be modified as appropriate, and the above-described contents regarding the materials used for the conductor, phosphor, discharge gas, glass tube, and the like are used. It is not limited to.

Examples of the present invention will be described below.
[Example 1]
A rare gas discharge lamp 1 (referred to as a lamp 1) was produced according to the following specifications in accordance with the configuration shown in FIGS.
Glass bulb: material: aluminosilicate glass, total length: 420 mm, outer diameter: 12 mm, inner diameter 11 mm (thickness 0.5 mm).
Enclosed gas: Xe gas, 22 kPa.
External electrode: foil-like aluminum, length 400 mm, width 1 mm.
-Phosphor layer: BAM, LAP, YGB.
First conductive material layer: carbon paste.
Second conductive material layer: carbon paste.
Here, a specific example of the method for manufacturing the rare gas discharge lamp according to the embodiment will be described. Needless to say, the method of manufacturing the rare gas discharge lamp shown here is an example, and can be changed as appropriate.
(1) A phosphor coating liquid is applied to the inside of a glass tube for a glass bulb and dried, and then a first conductive material layer and a second conductive material layer are formed (glass tube). The phosphor layer in the region of the edge of the surface was shaved and removed.
(2) A conductive paste as a starting conductor was applied and formed in a substantially C shape on the phosphor layer non-forming portion on the inner surface of the glass tube. Then, a conductive paste as a second conductive material layer was applied to a relatively small area on the phosphor layer non-formed portion on the center side of the glass tube from the position of the first conductive material layer. .
(3) Thereafter, the phosphor and the conductor were fired and fixed to the glass bulb.
(4) A predetermined rare gas was sealed inside the glass tube to hermetically seal the end.
(5) An external electrode formed into a tape shape made of aluminum was attached to the outer surface of the glass bulb. The external electrode was positioned so that only one electrode intersected the second conductive material layer.
Specific numerical values of the rare gas discharge lamp thus manufactured will be described. The first conductive material layer has a thickness of about 100 μm and a width of about 1 mm. The second conductive material layer has a thickness of about 100 μm, a circumferential length of about 3 mm, and a width of about 1 mm. It was 1 mm. The distance between the end of the electrode and the first conductive material layer was 4 mm, and the distance between the first conductive material layer and the second conductor was 2 mm.

[Example 2]
A rare gas discharge lamp 2 (hereinafter referred to as “lamp 2”) according to Example 2 has the same configuration as that of Example 1 except that the second conductive material layer is formed according to the configuration of FIG. Produced. In the lamp 2, as shown in FIG. 3, a second conductive material layer is formed on the phosphor layer non-forming portion so as to correspond to one and the other electrodes. Note that each of the second conductive material layers had a film thickness of about 100 μm, a circumferential length of about 3 mm, and a width of about 1 mm. The separation distance between the first conductive material layer and the second conductive material layer was 2 mm.

[Example 3]
A rare gas discharge lamp 3 according to Example 3 (hereinafter referred to as “Lamp 3”) is manufactured in the same manner as in Example 1 except that the second conductive material layer is formed according to the configuration of FIG. did. In the lamp 3, as shown in FIG. 4, a second conductive material layer is formed so as to correspond to one and the other electrodes, and further, on the second conductive material layer. A phosphor layer is arranged in a laminated state. The film thickness of the second conductive material layer is about 100 μm, the length in the circumferential direction is about 3 mm, and the width is about 1 mm. The distance between the first conductive material layer and the second conductive material layer is 2 mm. Met.

[Example 4]
A rare gas discharge lamp 4 (hereinafter referred to as “lamp 4”) according to Example 4 is manufactured in the same manner as in Example 1 except that the second conductive material layer is formed according to the configuration of FIG. did. In the lamp 4, as shown in FIG. 5, a second conductive material layer is formed so as to correspond to each of the one and the other electrodes, and these second conductive material layers are formed as phosphors. It is formed in a laminated state on the layer. The film thickness of the second conductive material layer is about 100 μm, the length in the circumferential direction is about 3 mm, and the width is about 1 mm. The distance between the first conductive material layer and the second conductive material layer is 3 mm. Met.

[Examples 5 to 7]
Examples 5 and 6 have the same configuration as that of Example 1 except that the separation distance between the first conductive material layer and the second conductive material layer was 10 mm, 30 mm, and 50 mm. , 7 (hereinafter referred to as “Lamp 5”, “Lamp 6”, “Lamp 7”).

[Comparative example]
A rare gas discharge lamp 8 (hereinafter referred to as “lamp 8”) according to a comparative example was manufactured as the same configuration as in Example 1 except that the second conductive material layer was not formed.

The lamps 1 to 8 were turned on under conditions of a voltage of 1.5 kV and a frequency of 50 kHz, and the brightness of the lamp was measured. The luminance measurement conditions were based on measuring the luminance (unit: cd / m ² ) using a spectroradiometer (SR-3, manufactured by Topcon Technohouse Co., Ltd.) at a distance of 60 cm from the measurement lamp.

The measurement results of the luminance of lamp 1 to lamp 4 and lamp 8 are collectively shown in FIG. In FIG. 6, the vertical axis indicates the measured value by the spectroradiometer, and the horizontal axis indicates the distance starting from the first conductive material layer (specifically, the center side end of the lamp of the first conductive material layer). That is, in the same figure, the luminance distribution of a region having a length of 100 mm from the end of the first conductive material layer is shown.
As described above, any of the lamps 1 to 4 according to the embodiment of the present invention can increase the light amount at the end portion with respect to the lamp 8 that does not include the second conductive material layer. Such a second conductive material layer is formed only on one side of the electrode, provided that the second conductive material layer satisfies the requirement of being disposed opposite to the single electrode at the center side of the lamp relative to the first conductive material layer. In addition, it may be formed on the electrodes on both sides. In addition, the function can be exhibited regardless of the intervening state of the dielectric layer other than the glass bulb such as the phosphor layer.

The brightness | luminance measurement result of the lamp 2, the lamps 5-7, and the lamp 8 is collectively shown in FIG. In FIG. 7 as well, the vertical axis shows the measured value by the spectroradiometer, and the horizontal axis starts from the first conductive material layer (specifically, the central end portion of the lamp of the first conductive material layer). This is a distance (unit: mm), that is, in the same figure, a luminance distribution in a region having a length of 100 mm from the end of the first conductive material layer is shown.
By forming at least the second conductive material layer, it is possible to suppress a decrease in the amount of light at the edge caused by the presence of the first conductive material layer. This can be recovered by forming at least a portion where the luminance is reduced in the vicinity of the first conductive material layer. Note that the distance between the first conductive material layer and the second conductive material layer is such that the second conductive material layer is closer to the first conductive material layer than the lamp end portion. The amount of light can be increased.

While various embodiments and examples of the present invention have been described above, it is needless to say that the present invention is not limited to the above configuration and can be modified as appropriate.
For example, the first conductive material layer has been described as being provided directly on the inner peripheral surface of the glass bulb, which is a non-forming portion of the phosphor layer. However, the first conductive material layer may be formed on the phosphor layer. no problem.
Further, in the portion where the first and second conductive material layers are formed, for example, another dielectric layer may be provided between the phosphor layer and the glass bulb.
Further, in the present invention, since the discharge form in the vicinity of the first conductive material layer can be improved regardless of the presence of the phosphor layer and other dielectric layers, a lamp using the same discharge principle can be used. For example, the present invention can be applied to a lamp that does not include a phosphor layer. Specifically, for example, in an excimer lamp that directly emits ultraviolet light emitted from a discharge of xenon gas from an ultraviolet light transmissive glass bulb, the vicinity of the excimer lamp having the first conductive material layer may be used. It is possible to improve the illuminance distribution.
In the above embodiment, the example in which the lead wire and the first conductive material layer are positioned on different sides of the lamp end portion has been described. However, the positional relationship is not limited thereto. In the present invention, as long as the first conductive material layer is located outside the lamp with respect to the second conductive material layer, the position of the power feeding connection portion of the lamp is not limited.

DESCRIPTION OF SYMBOLS 10 Noble gas discharge lamp 11 Glass bulb 12 Phosphor layer 13 External electrode 14 External electrode 15 1st electroconductive substance layer 16 2nd electroconductive substance layer

Claims (2)

It has a glass bulb in which a rare gas is sealed and one and the other electrodes are formed on the outer surface in the longitudinal direction.
The first conductive material is integrally formed on the inner surface of the glass bulb and over a region facing the one electrode, a region facing the other electrode, and a region facing between the electrodes. In a rare gas discharge lamp in which an active material layer is disposed,
In a region closer to the glass bulb center than the first conductive material layer and facing the one or other electrode on the inner surface of the glass bulb, the first conductive material layer is spaced apart from the first conductive material layer. A rare gas discharge lamp comprising two conductive material layers. 2. The rare gas discharge lamp according to claim 1, wherein the second conductive material layer is made of carbon paste.

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