JP2000082443A - Noble gas discharge lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a luminance distribution to provide a well-balanced luminance distribution by providing a light guide opening between external electrodes, which are arranged on the outside surface of a translucent discharge container and wherein their opposite side edges, each forming an uneven part in at least a part of the region in the lengthwise direction of the translucent discharge container with each of the projecting parts of one of the uneven parts facing to the corresponding recessed part of the other uneven part. SOLUTION: Each of opposite side edges of a pair of external electrodes 5A, 5B forms an uneven part in at least a part of the region in the lengthwise direction, and the electrodes are arranged shifted by half a pitch so that the recessed parts c1,c2 of the uneven part 5Aa of the other external electrode 5A facing projecting parts p1, p2 of the uneven part 5Ba of the one external electrode 5B. In a region where first inter-electrode distances x1, x2 which are the shortest distances between the projecting parts p1, p2 of the one external electrode 5B and the projecting parts p1,p2 adjacent to the recessed parts c1, c2 of the other external electrode 5A facing them are small, luminance in a light guiding opening 8 is large and a luminance distribution can be flattened by setting the shape of the unevenness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare gas discharge lamp in which a rare gas containing xenon is sealed, and a lighting device using the same.

[0002]

2. Description of the Related Art For image reading of an image reading device or the like,
2. Description of the Related Art There is known a rare gas discharge lamp in which a pair of external electrodes are disposed to face each other along the longitudinal direction of an elongated translucent discharge vessel.

FIG. 23 is a rear view showing a first conventional rare gas discharge lamp.

FIG. 24 is an enlarged sectional view of a plane which is also orthogonal to the tube axis.

[0005] In each figure, 101 is a translucent discharge vessel,
102 is a phosphor layer, 103 is an adhesive layer, 104A, 10
4B is a pair of external electrodes, 105 is a light guide opening, and 106 is a non-light guide opening.

[0006] The translucent discharge vessel 101 has both ends of a long and thin glass bulb sealed and xenon enclosed therein.

[0007] The phosphor layer 102 comprises a light-transmitting discharge vessel 101.
Are formed on the inner surface except for a portion facing a light guide opening 105 described later.

[0008] The adhesive layer 103 adheres the external electrode 104 to the outer surface of the translucent discharge vessel 101.

The pair of external electrodes 104A and 104B are opposed to each other so as to form an opening angle of, for example, 65 ° on the front and back sides of the translucent discharge vessel 101, respectively.
01 are arranged in parallel to the longitudinal direction.

The light guide opening 105 is provided with a pair of external electrodes 10.
4 of the pair of gaps formed between the phosphor layers 102
Is formed in the gap facing the portion where no is formed.

The non-light guide opening 106 is formed in a straight line along the longitudinal direction of the light-transmitting discharge vessel 101 as shown in FIG.

Therefore, a pair of external electrodes 104A, 1
Each of the opposing side edges of 04B is formed in a straight line.

Thus, the pair of external electrodes 104A, 10A
When a high-frequency AC voltage or a pulse voltage with a high repetition frequency is applied between 4B, ultraviolet light having a wavelength of 172 nm is emitted by the low-pressure discharge of xenon sealed in the translucent discharge vessel 101. The irradiation of the ultraviolet rays excites the phosphor of the phosphor layer 102 to generate visible light. The visible light is led out of the light-transmitting discharge vessel 101 through the light guide opening 105 and is used as a reading light source or the like.

In addition to the first conventional rare gas discharge lamp described above, a rare fine irregular portion having a regular small and substantially rectangular shape is formed on both opposing side edges of the pair of external electrodes on the non-light guide opening side. A gas discharge lamp (hereinafter, referred to as "second conventional rare gas discharge lamp") has been disclosed in Japanese Patent Application Laid-Open No. Hei 10-284010, for example, by referring to FIG. 13 and the related specification.

FIG. 25 is a development view of a light-transmitting discharge vessel and a pair of external electrodes in a second conventional rare gas discharge lamp.

In the figure, the same parts as those in FIG.

Reference numerals 104C and 104D denote a pair of external electrodes, each of which has a side edge 104C facing the non-light guide opening 106 side.
a, 104Da are substantially rectangular shaped portions 104Ca1, 1
04Da1 are arranged in large numbers, and the deformed portions 104Ca1, 1
The vertices of 04Da1 are formed to face each other. In the drawing, 104Cb and 104Db are opposing side edges on the light guide opening side. In the second conventional rare gas discharge lamp, the deformed portions 104Ca1, 104Da1 have a pitch of 4
mm and height is about 1.5 mm.

Thus, in the second conventional rare gas discharge lamp, the electric field concentrates on the apexes of the deformed portions 104Ca1 and 104Da1, and the deformed portions 104Ca1 and 104Da.
Discharge easily between the vertices. Therefore, even if the voltage applied to the external electrodes 104C and 104D is slightly reduced due to the power supply fluctuation, it is possible to reliably light the lamp. Therefore, it is described that the light emitted from the light guide opening 105 does not flicker. That is, the second conventional rare gas discharge lamp aims to reduce the flicker of discharge due to power supply fluctuation, and the pitch is 4 mm,
A fine irregular portion having a height of about 1.5 mm is formed on the opposite side edge of the external electrode.

[0019]

However, in the first and second conventional rare gas discharge lamps, when both of them become longer than 180 mm in tube length, the light guide opening 1 becomes inconvenient.
The amount of light led to the outside from the light-transmitting discharge vessel 101
It has been found that there is a problem that the light amount is extremely small near both ends in the longitudinal direction, and conversely the light amount near the center increases, and the uniformity of the luminance distribution in the light guide opening is significantly deteriorated. In this case, the temperature in the vicinity of both ends in the lighting state in the longitudinal direction of the translucent discharge vessel is reduced to 40 to 60 ° C., whereas the temperature in the vicinity of the center is about 130 ° C.
Had also reached. Further, the deterioration of the uniformity of the brightness distribution is as follows.
As the lamp current is increased and the light amount is increased, and as the tube length is increased, the contraction of the discharge is caused and becomes remarkable.

Further, in the case where the deformed portions like the second conventional rare gas discharge lamp face each other, in addition to the above, in the middle portion of the translucent discharge vessel 101, the period of the luminance in the longitudinal direction is added. It was found that the target unevenness repeatedly occurred. Hereinafter, a prototype example will be described with reference to FIGS.

FIG. 26 shows a light guide of an external electrode in a trial production example in which a convex portion and a concave portion of an uneven portion on opposite side edges of a pair of external electrodes are directly opposed like a second conventional rare gas discharge lamp. It is a development view centering on the opening for use.

FIG. 27 is a developed view centering on the non-light guide opening of the external electrode.

In each figure, the same parts as those in FIG. 25 are denoted by the same reference numerals, and description thereof will be omitted.

That is, the pair of external electrodes 104C, 10C
4D has an electrode length of 350 mm and a non-light guide opening 1
The concavo-convex portions 104Ca and 104Da are formed on the opposite side edge on the 06 side.
At the opposite side edge on the light guide opening 105 side.
Cb and 104Db, and external lead wire connection portions 104Cc and 104Dc at one end in the longitudinal direction, respectively. The projections p of the uneven portions 104Ca and 104Da are 11 mm high and 9 m wide from the light guide opening 105.
m. On the other hand, the uneven portions 104Ca, 10Ca
The 4 Da concave portion c is formed between the two convex portions p and has a width of 1
1 mm. Then, the width of the light guide opening 105 is 6 m.
m, the width of the non-light-guiding opening 106 is made
The inter-electrode distance between the convex portions p of 104 Da was set to 4 mm, and the inter-electrode distance between the concave portions c was set to 18 mm.
04C and 104D are provided on the outer surface of the translucent airtight container 101.

FIG. 28 is a graph showing the luminance distribution in the prototype example shown in FIGS. 26 and 27.

In the figure, the horizontal axis represents the position of the rare gas discharge lamp in the longitudinal direction, and the vertical axis represents the luminance on the screen (relative value). The total length L of the rare gas discharge lamp shown extending along the horizontal axis is 372 mm, and the length G of the translucent discharge vessel between the end caps ec at both ends is 340 mm.
And the outer diameter is 9.8 mm. Here, ol is a pair of external lead wires.

Points a and b on the horizontal axis indicate both ends of the effective emission length of the rare gas discharge lamp.

As is clear from the figure, in the prototype example,
In the effective emission length region, periodic unevenness with high luminance occurs in several places, although the reason is not clear.

At the end on the side where the external lead wire ol is attached, a particularly remarkable decrease in luminance is observed. Therefore, in the configuration as shown in FIG. 26, there is a practical problem due to uneven brightness in the effective emission length region and reduced brightness in the end region.

An object of the present invention is to provide a rare gas discharge lamp configured to control a luminance distribution in a longitudinal direction of a translucent discharge vessel, and an illumination device using the same.

Another object of the present invention is to provide a rare gas discharge lamp having a good uniformity of luminance distribution in the longitudinal direction of the translucent discharge vessel, and an illumination device using the same.

[0032]

According to the present invention, there is provided a rare gas discharge lamp according to the present invention, comprising: an elongated light-transmitting discharge vessel; and a discharge medium mainly composed of a rare gas containing xenon sealed in the light-transmitting discharge vessel. A phosphor layer disposed on the inner surface side of the light-transmissive discharge vessel; and opposing along the longitudinal direction of the light-transmissive discharge vessel, and at least a part of the longitudinal edges of the phosphor layer have irregularities. And a pair of external parts disposed on the outer surface of the light-transmitting discharge vessel, with the concave part of the other concave-convex part facing the convex part of the one concave-convex part. And a light guide opening formed in the translucent discharge vessel between the pair of external electrodes.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

(Regarding Translucent Discharge Vessel) The translucent discharge vessel may be made of soft glass such as soda lime glass or lead glass, but may be made of hard glass such as borosilicate glass, semi-hard glass or quartz glass if necessary. Further, a material other than glass, for example, a translucent ceramic may be used. In short, any material that satisfies the translucency and airtightness, and the fire resistance and workability at the operating temperature of the rare gas discharge lamp is acceptable. .

The translucent discharge vessel may have any shape in a cross section perpendicular to the longitudinal direction. Generally, a cross-sectional shape is used, but an elliptical shape or a square shape can be used if necessary.

Further, the inner diameter of the translucent discharge vessel is about 13
mm or less is suitable, but is generally not particularly limited.

Further, that the light-transmitting discharge vessel is elongated means that the diameter is at least twice the diameter of the discharge vessel.
It can be set to any length required by the lighting device. However, the present invention has a relatively long pipe length of 180 to 5 mm.
It is particularly effective in a rare gas discharge lamp of 00 mm.

(Discharge Medium) The discharge medium is mainly composed of a rare gas containing xenon. Xenon excites the phosphor with ultraviolet rays having a wavelength of 172 nm generated by the low-pressure discharge to generate visible light. Work for.
If necessary, in addition to xenon as a rare gas, krypton, neon, argon, etc. may be mixed and sealed to reduce the firing voltage due to the Penning effect,
Further, when krypton is added, it is possible to suppress the flicker of brightness at the time of dimming.

The pressure for filling the rare gas is not particularly limited, but is preferably from 133 Pa to 26.6 kPa.

(Regarding Phosphor Layer) The phosphor layer functions to convert ultraviolet light generated by the low-pressure discharge of xenon into visible light or ultraviolet light of a different wavelength as described above. It is disposed directly or indirectly on the inner surface.

Indirect means, for example, a reflective film mainly composed of particles of metal oxide having a high visible light reflectance such as titanium oxide or alumina having an average particle diameter of 50 to 100 nm on the inner surface of a light-transmitting discharge vessel and / or The method includes forming a protective layer of a metal oxide layer containing alumina fine particles as a main component, and disposing a phosphor layer on the inner surface side.

The fluorescent material is LaP for monochromatic reading.
O4: A green-emitting phosphor such as Ce or Tb can be used. In addition, as a light source for a backlight device,
A phosphor that emits white light, such as a three-wavelength phosphor or a calcium halophosphate phosphor, can be freely selected.

Further, a non-fluorescent substance such as a binder or an electron-emitting particle can be mixed in the fluorescent layer in addition to the fluorescent substance.

Further, the position where the phosphor layer is disposed in the translucent discharge vessel will be described. That is, the phosphor layer should be disposed on at least the entire inner peripheral surface of the region surrounding the discharge space of the translucent discharge vessel, or disposed on other portions except for the portion facing the light guide opening. General. The latter is called aperture type. In order to form the phosphor layer except for the portion facing the light guide opening, the phosphor layer is formed on the entire inner surface of the light-transmitting discharge vessel, and then the phosphor layer in the portion facing the light guide opening is formed. The phosphor layer may be removed by peeling the layer using a scraper, or the phosphor layer may be formed by partial coating except for the portion facing the light guide opening from the beginning. In addition, the same process can be performed when a reflective film is formed, and can be removed simultaneously with the phosphor layer.

Further, a reflection film made of metal oxide fine particles is formed on the inner surface of the light-transmitting airtight container except for the light guide opening, and the phosphor layer is formed over the entire circumference including the light guide opening. This is called a reflection type. The present invention may have any of an aperture type and a reflection type.

(Regarding the External Electrodes) The external electrodes are disposed on the outer surface of the light-transmitting discharge vessel such that a pair of the external electrodes are spaced apart from each other along the longitudinal direction of the light-transmitting discharge vessel. Therefore, a pair of gaps where no external electrodes are provided are formed around the translucent discharge vessel. These gaps function to ensure insulation between the pair of external electrodes, and at least one of them can be used as at least a part of a light guide opening described later.

In the pair of external electrodes, at least one of the side edges on both sides along the longitudinal direction and at least a part of the longitudinal direction, the opposing side edges form an uneven portion. In addition, the convex portions of the concave and convex portions of the one external electrode are arranged so as to be shifted by a half pitch so that the concave portions of the concave and convex portions of the other external electrode face each other. The shortest distance between the convex portion of the concave and convex portion of one external electrode and the convex portion adjacent to the concave portion of the concave and convex portion of the other external electrode facing the other external electrode is defined as a first inter-electrode distance. . Further, when the shortest distance between the convex portion and the concave portion facing the convex portion is defined as the second inter-electrode distance, it is longer in the longitudinal direction to make the second inter-electrode distance larger than the first inter-electrode distance. This is effective for controlling the luminance distribution along the line.

Further, the uneven portion can be formed in one or both of the light guide opening and the non-light guide opening of the external electrode. When forming an uneven portion on the side edge of the external electrode on the light guide opening side, it is desirable to linearly shape the light guide opening with a light shielding material. In general, it is desirable to form a concavo-convex portion on the opposite side edge on the non-light guide opening side.

Further, the uneven portion can be formed in the entire region or a partial region in the longitudinal direction of the external electrode.

Further, the first inter-electrode distance can be changed along the longitudinal direction of the external electrodes in the concavo-convex portions formed on the opposite side edges of the pair of external electrodes. That is, in the region where the first inter-electrode distance is relatively small, the brightness in the light guide opening by the rare gas discharge is larger than in the region where the first inter-electrode distance is relatively large. However, it should be noted that this phenomenon does not occur for a single protrusion, but for a plurality of protrusions and therefore for a region having a certain length on average. For this reason, in the present invention, there is an extremely important effect that the unevenness portion flattens the luminance distribution in the longitudinal direction of the translucent discharge container. For example, by setting the distance between the first electrodes in the end region in the longitudinal direction of the translucent discharge vessel to be smaller than that in the intermediate region, it is possible to obtain a luminance distribution with good uniformity along the longitudinal direction as much as possible. Can be. Conversely,
In the conventional rare gas discharge lamp in which the opposing side edges are both linear and parallel, the luminance distribution in the central region is more than the luminance distribution generally obtained in which both end regions are reduced and the central region is relatively high. When it is desired to obtain a luminance distribution in which is emphasized high, the distance between the first electrodes in the uneven portion in the central region may be made relatively smaller than that in both ends.

Furthermore, the length, ie, the pitch, of the protrusions and recesses of the uneven portion formed on the opposite side edge of the external electrode with respect to the longitudinal direction of the light-transmitting discharge vessel may be constant, or may be constant. May be changed along the line. The mode of the change in this case may be either continuous or stepwise.

Furthermore, the shape of the tip of the convex portion in the uneven portion may be an appropriate shape such as a rectangle or a semicircle. However, when the basic shape is rectangular, the discharge is attracted and spreads to the vicinity thereof, and therefore, it is particularly effective for leveling the luminance distribution. When the convex portion has a rectangular shape and the corner portion is appropriately rounded, it is convenient for punching and attaching the external electrode, and there is no adverse effect on the control action of the luminance distribution.

On the other hand, the shape of the concave portion in the uneven portion is
It is preferable that the bottom has a linear shape or an inverted round shape.

Next, the manufacture of the external electrodes will be described.

The external electrode may be formed by attaching a thin plate of a conductive metal such as aluminum to the outer surface of the translucent discharge vessel with an adhesive, or by applying a conductive paste, drying and firing. Good. Further, a conductive metal may be directly formed by deposition or the like.

(Regarding Light Guide Opening) The light guide opening is provided to guide the light generated in the light-transmitting discharge vessel to the outside for use. If a light guide opening is formed along the longitudinal direction of the light-transmissive discharge vessel in order to utilize light distributed in the longitudinal direction of the elongated light-transmissive discharge vessel, the light-guiding opening is arranged around the light-transmissive discharge vessel. It is preferable to form it in at least one of a pair of gaps formed by a pair of external electrodes provided.
However, if necessary, a slit may be formed along the longitudinal direction at the center of one or both external electrodes to form a light guide opening.

In the case of the light guide opening having the latter configuration, it is preferable that both sides are defined by the sides of the pair of external electrodes. It is acceptable to be located at Further, when a gap in which the uneven portion is formed on the opposing side edge between the pair of external electrodes and a gap not formed are formed, the light guide opening is formed in the latter gap. Easy to use for reading, etc. However, if necessary, the light guide opening can be formed in the former gap.

(Other Configurations) In order to insulate between external electrodes, a transparent insulating coating can be formed outside the external electrodes. In this case, the transparent insulating coating is disposed in close contact with and surrounding the translucent discharge vessel and the pair of external electrodes. Therefore, the light guide opening and the gap on the opposite side are also covered together. For this reason, the light led out of the light-guiding light-transmitting portion passes through the transparent insulating coating and is taken out of the rare gas discharge lamp.

Further, the transparent insulating coating can be formed by dipping a transparent transmissive vessel provided with external electrodes into transparent silicone and solidifying the same. Of course, it is desirable to connect the lead wires for supplying power to the external electrodes in advance.

Further, if necessary, for a backlight device or the like, the transparent insulating coating can be covered with a transparent heat-shrinkable tube. As the transparent heat-shrinkable tube, a heat-shrinkable tube made of a material having relatively excellent heat resistance such as a transparent fluororesin is preferable.

Further, when it is not necessary to leak light from the gap on the opposite side of the light guide opening, a light shielding film or a metallic reflection film may be added to the above-mentioned reflection film or separately from the reflection film. It can be formed on the outside.

(Regarding the Operation of the Present Invention) In the rare gas discharge lamp of the present invention having the above-described structure, a concavo-convex portion is formed on each of the opposed side edges of the pair of external electrodes, and one of the external electrodes is formed. Since the concave portion of the other external electrode is arranged so as to face the convex portion, unevenness of the luminance distribution that occurs when the convex portions face each other does not occur. Although the reason is not always clear, a new and useful effect is obtained in that the luminance distribution in the region where the uneven portion is formed is leveled.

Accordingly, by arranging the uneven portion in a desired region along the longitudinal direction of the light-transmitting discharge vessel and appropriately setting the distance between the electrodes, the unevenness can be achieved along the longitudinal direction of the rare gas discharge lamp. A desired luminance distribution can be realized.

However, the present invention is not intended only to obtain a constant luminance distribution in the longitudinal direction of the translucent discharge vessel. For example, in order to use light derived from the intermediate region excluding the vicinity of both ends, the luminance distribution in the intermediate region can be made constant. In addition, in order to make the illuminance distribution on the illuminated surface separated by a predetermined distance constant, the light amount near both ends of the translucent discharge vessel can be made larger than that at the middle part.

A rare gas discharge lamp according to a second aspect of the present invention is the rare gas discharge lamp according to the first aspect of the present invention. The shortest distance between the convex portion of the convex portion and the convex portion adjacent to the concave portion of the concave / convex portion of the other external electrode facing the other is defined as a first inter-electrode distance, and When the shortest distance is the distance between the second electrodes, the first distance
Is characterized in that the inter-electrode distance is smaller than the second inter-electrode distance.

In the present invention, in the region where the uneven portions are formed on the opposite side edges of the pair of external electrodes, the uneven portions of the other external electrode obliquely oppose the convex portions of the uneven portion of one external electrode. The discharge is attracted around the first inter-electrode distance between the convex portion of the convex portion and the discharge spreads along the convex portion, and as a result, the luminance distribution in the region where the concave / convex portion is formed Is considered to be obtained.

According to the rare gas discharge lamp of the third aspect of the present invention, in the rare gas discharge lamp of the second aspect, a pair of external electrodes in at least one end region along the longitudinal direction of the light-transmitting discharge vessel are provided. The distance between the electrodes is smaller than the first distance between the electrodes in the central region.

In the present invention, in the end region, the opposing side edges of the pair of external electrodes may form an uneven portion,
It may be linear.

The distance between the electrodes when the opposite side edge of the end region is uneven is the first distance between the electrodes.

When the opposing side surface of the end region is linear, the distance between the electrodes is the distance between the electrodes in the direction perpendicular to the opposing side edge.

Further, the end region may be either one end or both ends of the translucent discharge vessel.

Further, in the case of the end region on one end side of the translucent discharge vessel, the end region may be the end to which the external lead wire is connected or the end on the opposite side.

Thus, the end region of the translucent discharge vessel is
Since the temperature during lighting is low because the cooling is easier than in the central area, the discharge current does not easily flow. For this reason,
The brightness is lower than that in the central region of the translucent discharge vessel.

On the other hand, in the present invention, since the distance between the electrodes in the end region is relatively small, the discharge current increases, so that the temperature in the end region rises and the luminance improves. As a result, the brightness distribution over the entire length of the translucent discharge vessel is improved.

In particular, when an external lead wire is connected to one end of a pair of external electrodes, the heat capacity increases, and the temperature drops remarkably. Therefore, when the present invention is applied to an end region to which the external lead wire is connected, More effective.

According to the rare gas discharge lamp of the fourth aspect of the present invention, in the rare gas discharge lamp according to the second or third aspect, at least one end region along the longitudinal direction of the light-transmitting discharge vessel has an opposite side edge. Are linear, and the inter-electrode distance is smaller than the first inter-electrode distance in the central region.

In the present invention, a more effective configuration is specified when it is desired to correct a decrease in luminance in an end region. That is, the end region is made linear without forming an uneven portion on the opposing side edges of the pair of external electrodes, and the distance between the electrodes is reduced by the first interelectrode distance in the region where the uneven portion is formed on the opposing side surface. By making the end area smaller, the discharge current in the end region can be increased to increase the luminance.

Further, in the remaining area where the uneven portion is formed on the opposing side edge, the brightness is leveled.

Further, even if an uneven portion is formed on the opposing side edge of the remaining area other than the end area where the opposing side edge is linear, the distance between the first electrodes can be reduced by the length of the translucent discharge vessel. By appropriately adjusting and setting according to the area along the direction,
Since the discharge current can be adjusted according to the region, it is possible to finely adjust the luminance distribution.

Therefore, according to the present invention, the uniformity of luminance can be increased along the longitudinal direction of the translucent discharge vessel of the rare gas discharge lamp.

Further, by applying the structure of the present invention to the end region to which the external lead wire is connected, the luminance can be leveled over substantially the entire length of the light-transmitting discharge vessel. However, the present invention is not only effective at the end to which the external lead wire is connected, but can also be applied to the end where the temperature drops for other reasons. Further, in any case, the temperature of the end portion of the translucent discharge vessel is more likely to be lower than that of the center region, and therefore, the present invention can be applied to any end portion.

A rare gas discharge lamp according to a fifth aspect of the present invention is the rare gas discharge lamp according to any one of the first to fourth aspects, wherein the pair of external electrodes are opposed to each other along the longitudinal direction of the translucent discharge vessel. The pitch of the uneven portion on the side edge is 10 to 40 m
m.

According to the present invention, a preferable pitch of the concavo-convex portions on the opposite side edges of the pair of external electrodes is defined.

In other words, it is effective to level the luminance when the pitch of the uneven portions is large to some extent, and when the pitch is less than 10 mm and more than 40 mm, the effect of the luminance leveling is small. Therefore, favorable effects can be obtained in the above range.

A rare gas discharge lamp according to a sixth aspect of the present invention is the rare gas discharge lamp according to any one of the first to fifth aspects, wherein the pair of external electrodes are opposed to each other along the longitudinal direction of the translucent discharge vessel. The pitch of the uneven portion on the side edge is 10 to 30 m
m.

According to the present invention, the optimum pitch of the concavo-convex portions on the opposite side edges of the pair of external electrodes is defined.

A rare gas discharge lamp according to a seventh aspect of the present invention is the rare gas discharge lamp according to any one of the first to sixth aspects, wherein the pair of external electrodes are opposed to each other along the longitudinal direction of the translucent discharge vessel. The feature is that the pitch of the concavo-convex portion on the side edge changes along the longitudinal direction.

When the pitch of the uneven portion is reduced, the brightness increases, and when the pitch is increased, the brightness decreases.

In order to improve the uniformity of the luminance along the longitudinal direction of the light-transmitting discharge vessel, the pitch of the concavo-convex portions on the opposite side edges of the external electrodes in both end regions of the light-transmitting discharge vessel is required. What is necessary is just to set relatively small, and to set relatively large the pitch of the uneven | corrugated part in a center area | region. However, the present invention is not intended only to improve the uniformity of the luminance along the longitudinal direction of the translucent discharge container, and therefore, the present invention is also applied to obtain a desired luminance distribution. be able to.

In practicing the present invention, the longitudinal direction of the translucent discharge vessel is divided into an appropriate number of areas such as, for example, three areas at the center and both ends. The pitch can be set the same.

Further, the pitch can be changed continuously or stepwise within one area.

The rare gas discharge lamp according to the invention of claim 8 is the rare gas discharge lamp according to any one of claims 1 to 7, wherein the pair of external electrodes are opposed to each other along the longitudinal direction of the translucent discharge vessel. It is characterized in that the pitch of the concavo-convex portions on the side edges is relatively large in the central region in the longitudinal direction and relatively small in at least one end region.

The present invention defines a structure suitable for obtaining a rare gas discharge lamp having a good uniformity of luminance along the longitudinal direction of the translucent discharge vessel.

According to a ninth aspect of the present invention, there is provided a rare gas discharge lamp comprising: an elongated light-transmitting discharge vessel; a discharge medium mainly containing a rare gas containing xenon sealed in the light-transmitting discharge vessel; A phosphor layer disposed on the inner surface side of the container; and a central region in which a distance between the electrodes in at least one end region along the longitudinal direction of the translucent discharge container is opposed to each other along the longitudinal direction of the translucent discharge container. A pair of external electrodes set to be smaller than the inter-electrode distance in and disposed on the outer surface of the translucent discharge vessel; and a light guide opening formed in the translucent discharge vessel between the pair of external electrodes; It is characterized by having.

The present invention divides the light-transmitting discharge vessel into a plurality of regions along the longitudinal direction and changes the facing distance between the external electrodes according to the regions, thereby reducing the intensity of the discharge for each region. This is based on the knowledge that it can be controlled. This makes it possible to control the luminance distribution over the entire length of the translucent discharge container as desired.

Therefore, the rare gas discharge lamp of the present invention is suitable for various uses including reading.

According to the present invention, a pair of external electrodes may be provided with a concavo-convex portion on opposing side edges, or the opposing side edges may be linear in one region. In the case of an uneven portion, the inter-electrode distance in the present invention is the first inter-electrode distance.

According to a tenth aspect of the present invention, there is provided an illuminating device comprising: an illuminating device main body; and the rare gas discharge lamp according to any one of the first to ninth aspects provided in the illuminating device main body. Features.

In the present invention, the "illumination device" is a broad concept applicable to all devices that use light generated by a rare gas discharge lamp for some purpose. For example, it is applicable to an image reading device, a backlight device such as a liquid crystal device, a lighting fixture, a signal light device, and the like.

It is assumed that the illumination device includes, for example, OA equipment such as a copying machine, a facsimile, and a scanner, and information processing equipment such as a personal computer, which incorporate the image reading device and the backlight device.

The "illumination device main body" means the remaining portion of the illumination device excluding the rare gas discharge lamp.

[0102]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first example of the rare gas discharge lamp of the present invention.
It is a partially notched front view which shows embodiment.

FIG. 2 is an enlarged cross-sectional view of the same.

FIG. 3 is a developed view centered on the light guide opening of the pair of external electrodes.

FIG. 4 is a developed view centering on the non-light guide opening of the pair of external electrodes. In each figure, 1 is a translucent discharge vessel, 2 is a reflective film, 3 is a phosphor layer, 4 is an adhesive layer, 5A and 5B are a pair of external electrodes, 6 is a transparent silicone film, and 7 is a transparent heat film. Shrink tube, 8 is light guide opening, 9
Denotes a non-light guide opening.

The translucent discharge vessel 1 is made of an elongated transparent soft glass bulb having an outer diameter of 9.8 mm, a wall thickness of 0.55 mm, and a total length of 355 mm with both ends sealed, and about 20 kPa of xenon as a rare gas filled therein. ing. In addition, 1a is an exhaust chip, which is formed by closing an exhaust pipe provided at one end of the translucent discharge vessel 1, and evacuating the inside of the translucent discharge vessel 1 through the exhaust pipe, such as xenon. Is sealed after sealing.

The reflection film 2 has an average particle size of 50 to 100 n.
It is formed on the inner surface of the translucent discharge vessel 1 except for the portion facing the light guide opening 8, with the main component being titanium oxide particles of m.

The phosphor layer 3 is made of LaPO4: C which emits green light.
The e-fluorescent material is formed on the inner surface of the translucent discharge vessel 1 except for the portion facing the light guide opening 8 except for the remaining portion.

Each of the pair of external electrodes 5A and 5B is made of an elongated aluminum foil having a total length of 350 mm, and has concave and convex portions 5Aa and 5Ba on opposing side edges with the non-light guide opening 9 interposed therebetween.
A linear portion 5A on the opposite side edge with the light guide opening 9 interposed therebetween.
b, 5Bb, and external lead wire connection portions 5Ac, 5Bc at one end in the longitudinal direction.

Further, the pair of external electrodes 5A and 5B are separated and opposed to each other via the adhesive layers 4 and 4 so as to extend along the longitudinal direction of the translucent discharge vessel 1. And is disposed on the outer surface of the translucent discharge vessel 1.

Further, the uneven portions 5Aa, 5Ba of the pair of external electrodes 5A, 5B are formed over the whole along the longitudinal direction. As shown in FIG. 4, the external lead wire connecting portions 5Ac, 5Bc are formed. 60mm
Is defined as a first region R1, and the remaining portion 290 mm is divided into a second region R2, which has different specifications. That is, in the uneven portions 5Aa1 and 5Ba1 in the first region R1, the protrusion p1 has a height of 11 mm and a width of 9 mm from the linear portions 5Ab and 5Bb on the back side, and the recess c is formed between the protrusions p. , Its width is 11 mm.

On the other hand, in the uneven portions 5Aa2 and 5Ba2 in the second region R2, the protrusion p2 has a height of 9 mm from the linear portions 5Ab and 5Bb on the back side, and the width of the concave portion c is the first region. 11 mm which is the same as that in R1.

The transparent silicone film 6 is formed on the external electrodes 5A,
The rare gas discharge lamp is coated from above 5B, but is applied by dip.

The transparent heat-shrinkable tube 7 is made of a transparent fluororesin, and covers the rare gas discharge lamp from above the transparent silicone film 6.

The light guide opening 8 is defined by the linear portions 5Ab and 5Bb of the external electrodes 5A and 5B in the longitudinal direction of the light-transmitting discharge vessel 1 and has a width of 6 mm.

The non-light guide opening 9 is connected to the external electrode 5A,
5B are defined in the longitudinal direction of the translucent discharge vessel 1,
The concavo-convex portions 5Aa and 5Ba are formed so as to face each other with a half pitch shift. That is, the concave portion c of the other external electrode faces the protruding portion p of the one external electrode 5A.

Thus, in region R1, the shortest distance is between protrusion p1 of one external electrode, for example, 5A, and protrusion p1 adjacent to recess c1 of the other external electrode 5B, which faces directly. The first interelectrode distance x1 is about 3 mm in the developed view of FIG. Further, a second inter-electrode distance y1 which is the shortest distance between the protrusion p1 of the pair of external electrodes 5A and the recess c1 of the other external electrode 5B directly opposite thereto.
Is 10 mm in the developed view of FIG.

Next, in the region R2, the first inter-electrode distance x2 which is the shortest distance between the protrusion p2 of one external electrode, for example, 5A, and the concave portion c2 of the other external electrode 5B, which faces the protrusion p2. Is about 8 mm in the developed view of FIG. Further, the second inter-electrode distance y2, which is the shortest distance between the protrusion p2 of the pair of external electrodes 5A and the concave portion c2 of the other external electrode 5B directly opposite to the protrusion p2, is 13 mm in the developed view of FIG. It is.

Therefore, x1 <x2, x1 <y1, x
The relationship of 2 <y2 holds.

Further, the specifications of the rare gas discharge lamp of this embodiment other than the above-described external electrodes 5A and 5B are the same as those of the prototype shown in FIGS. 26 and 27.

FIG. 5 shows a first example of the rare gas discharge lamp of the present invention.
6 is a graph showing a luminance distribution in the embodiment.

In the figure, the abscissa indicates the position of the rare gas discharge lamp in the longitudinal direction, and the ordinate indicates the screen luminance (relative value). The total length L of the rare gas discharge lamp shown on the horizontal axis is 372 mm, and the length G of the translucent discharge vessel between the end caps at both ends is 340 mm. Note that o
1 is a pair of external lead wires.

Points a and b on the horizontal axis indicate both ends of the effective emission length of the rare gas discharge lamp.

As is clear from FIG. 28 and in comparison with FIG. 28, in the present embodiment, the brightness distribution is flat as a whole, and the region R1 on the side of the end from which the external lead wire ol is led out. It can be understood that the light emission amount of the light-emitting element is relatively increased, which contributes to the uniformity of the luminance distribution. For this reason, a brightness distribution with good uniformity is realized over the entire effective emission length.

FIG. 6 shows a second example of the rare gas discharge lamp of the present invention.
FIG. 4 is a partially cutaway rear view showing the embodiment.

FIG. 7 is a partially cutaway development view centered on the light guide opening of the pair of external electrodes.

FIG. 8 is a partially cutaway development view centered on the non-light guide opening of the pair of external electrodes.

FIG. 9 is an enlarged sectional view of the external electrode structure.

In each figure, the same parts as those in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, as shown in FIG. 8, a pair of external electrodes 5A and 5B is formed by first and third regions R having a length of 60 mm on both ends of the entire length (340 mm).
1, R3, and is different in that the remaining intermediate portion having a length of 220 mm is divided into the second region R2.

That is, the first and third regions R1, R
3, the uneven portions 5Aa1 of the external electrodes 5A, 5B,
5Aa3, 5Ba1, and Aa3 are such that the protrusions p1 and p3 are 11 mm in height and 10 mm in width from the linear portions 5Ab and 5Bb on the rear side, and the recesses c1 and c3 are formed between the protrusions p1 and p3, respectively. Its width is 10 mm.

Therefore, the first inter-electrode distances x1, x3
Is about 2 mm in the developed view shown in FIG. Further, the second distances y1 and y3 between the electrodes are similarly 8 mm.

On the other hand, in the second region R2, the projections and depressions 5Aa2 and 5Ba2 are 9 mm in height and 10 mm in width from the linear portions 5Ab and 5Bb on the back side.
The recess c2 is also 10 mm wide.

Therefore, the first inter-electrode distance x2 is about 5 mm in the developed view shown in FIG. Also, the second
Is similarly 10 mm.

The external electrodes 5A and 5B are arranged in a predetermined positional relationship by preparing an external electrode assembly 5 having the structure shown in FIG. 9 and affixing it to the outer surface of the translucent discharge vessel 1. It is a configuration that is provided.

That is, the external electrode structure 5 comprises a colorless and transparent synthetic resin film 51, a first adhesive layer 52, an external electrode 5A of aluminum foil, a second adhesive layer 53, and a release paper 54.

At the time of sticking, after the release paper 54 is peeled off, it is stuck to a predetermined position of the translucent discharge container 1 by the second adhesive layer 53. Therefore, the outside of the external electrode 5A is protected by the colorless and transparent synthetic resin film 51.

FIG. 10 is a graph showing a luminance distribution in the second embodiment of the rare gas discharge lamp of the present invention.

In the figure, the horizontal axis shows the position of the tube surface along the longitudinal direction of the rare gas discharge lamp, and the vertical axis shows the relative luminance (%). The points a and b on the horizontal axis indicate the ends of the effective emission length of the rare gas discharge lamp.

As can be understood from the drawing, in this embodiment, the relative luminance in the regions R1 and R3 at both ends is about 5% higher than that in the central region R2. In the central region R2, the luminance distribution is substantially constant.

FIG. 11 is a partially cutaway rear view showing a third embodiment of the rare gas discharge lamp of the present invention.

FIG. 12 is a partially cutaway development view centered on the light guide opening of the pair of external electrodes.

FIG. 13 is a partially cutaway development view centered on the non-light guide opening of the pair of external electrodes.

In each of the figures, the same parts as those in FIGS. 6 to 9 are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, as shown in FIG. 13, the external electrodes 5A and 5B have a total length of 340 mm and a 90 mm length portion on the end side where the external lead wire connection portions 5Ac and 5Bc are located in the first region. R1 and a portion having a remaining length of 250 mm is divided as a second region R2. In the first region R1, the external electrodes 5A and 5B form parallel linear portions 5Ad and 5Bd. Primarily different.

That is, the inter-electrode distance z1 on the non-light guide opening 9 side in the first region R1 is 5 mm. The distance between the electrodes in the light guide opening 8 is also 5 mm.

In the second region R2, the projections and depressions 5Aa2 and 5Ba2 are 10 mm in height and 10 mm in width from the linear portions 5Ab and 5Bb on the back side.
The recess c2 is also 10 mm wide. The protrusion p2
Has a larger radius at the corners than in the second embodiment.

Therefore, the first distance x2 between the electrodes is approximately 5.5 mm in the developed view shown in FIG. Further, the second distance y2 between the electrodes is 10 mm in the developed view of FIG.

As described above, in this embodiment, z1 <
The relationship x2 <y2 holds.

FIG. 14 is a graph showing a luminance distribution in the third embodiment of the rare gas discharge lamp of the present invention.

In the figure, the horizontal axis represents the position of the tube surface along the longitudinal direction of the rare gas discharge lamp, and the vertical axis represents the relative luminance (%). In addition, the point b with the arrow on the horizontal axis indicates the end of the effective emission length of the rare gas discharge lamp, and the left side of the figure is the external lead wire side.

As can be understood from the figure, almost uniform luminance is obtained over the entire effective light emission length.

FIG. 15 is a graph showing a luminance distribution in the comparative example.

The same parts as those in FIG. 14 are denoted by the same reference numerals, and description thereof will be omitted.

The comparative example is a rare gas discharge lamp having the same specifications except that the entire length of the external electrodes 5A and 5B is constituted by a linear portion similar to the linear portion in the region R1 in the present embodiment.

As is clear from the figure, the brightness of the end region on the side of the external lead wire connection portion is reduced, and the brightness distribution is not uniform.

FIG. 16 is a rear view showing a fourth embodiment of the rare gas discharge lamp of the present invention.

In the figure, the same portions as those in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a pair of external electrodes 5A, 5B
Uneven portions 5Aa, 5B having the same pitch over the entire length of
The difference is that b is formed.

Also in this embodiment, the first inter-electrode distance x is configured to be smaller than the second inter-electrode distance y.

Thus, also in the present embodiment, the portion forming the first inter-electrode distance x along the longitudinal direction of the external electrodes 5A, 5B forms the second inter-electrode distance y. As a result of being distributed between the parallel portions, the discharge is attracted to the portion at the first inter-electrode distance x, and the discharge is diffused therefrom to improve the uniformity of the luminance distribution as a whole. .

FIG. 17 is a rear view showing a fifth embodiment of the rare gas discharge lamp of the present invention.

In the figure, the same parts as those in FIG. 16 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a pair of external electrodes 5A, 5B
Is divided into five regions R1 to R5 along the longitudinal direction, and the pitch of the concavo-convex portions on the opposite side edge is set in three stages.

That is, the length of the pair of external electrodes 5A and 5B is divided into approximately five equal parts in the longitudinal direction, and first to fifth regions R1 to R5 are set from one end to the other end. In the fifth regions R1 and R5, concave and convex portions 5Aa1 and 5Ba1 having the smallest pitch and 5Aa5 and 5Ba5 are formed. In these regions R1 and R5, seven first inter-electrode distances x1 and x5 are respectively formed, and the shapes of the protrusions p1 and p5 are semicircular.

In the second and fourth regions R2 and R4, the uneven portions 5Aa2, 5Ba2 and 5A
a4 and 5Ba4. In these regions R2 and R4, four first inter-electrode distances x2 and x4 are formed, respectively, and the shapes of the convex portions p2 and p4 are rectangular with rounded corners.

In the central third region R3, the uneven portions 5Aa3 and 5Ba3 having the largest pitch are formed. In this region R3, one first inter-electrode distance x3 is formed, and the shape of the convex portion p3 is a rectangle with rounded corners.

Thus, in the present embodiment, by changing the pitch of the uneven portions 5Aa, 5Ba,
The number of the first inter-electrode distances x1 to x5 attracting the discharge changes according to the regions R1 to R5, and the discharge current changes for each region, so that the middle region is flat and both end regions have higher luminance distribution than the middle region. Can be This luminance distribution is suitable for performing linear illumination with uniform illuminance at a position separated from the rare gas discharge lamp by a predetermined distance.

FIG. 18 is a rear view showing a sixth embodiment of the rare gas discharge lamp of the present invention.

FIG. 19 is an enlarged cross-sectional view of the same central region in the longitudinal direction.

FIG. 20 is an enlarged transverse sectional view of the same end region.

In each figure, the same parts as those in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, the configuration of the external electrodes 5A and 5B is different.

That is, the first and third regions are divided into first and third regions R1 and R3 at both ends and a second region R2 at the center along the longitudinal direction of the external electrodes 5A and 5B. The inter-electrode distances z1 and z3 in R1 and R3 are set relatively small, and the inter-electrode distances z2 in the second region R2.
Is set relatively large. The opposing side edges of the non-light-guiding openings 10 of the external electrodes 5A, 5B in the respective regions R1, R2, R3 are parallel linear portions.

Thus, also in the present embodiment, by changing the distance between the electrodes according to the region, the discharge current for each region changes, and the brightness of both end regions R1 and R3 increases, and the brightness as a whole increases. The uniformity of the distribution is improved.

FIG. 21 is a conceptual sectional view showing an image reading apparatus as a first embodiment of the illuminating device of the present invention. In FIG. 21, 11 is a rare gas discharge lamp, 12 is a light receiving means,
13 is a signal processing means, 14 is a document placing surface, 15 is a reflection plate, and 16 is a case.

The rare gas discharge lamp 11 shown in FIG. 6 is used. Then, the light emitted from the light guide opening of the rare gas discharge lamp 11 is applied to an original (not shown) via the original mounting surface 14.

The light receiving means 12 is arranged to receive the light reflected from the document surface.

The signal processing means 13 processes the output signal of the light receiving means 12 to form an image signal. Document loading surface 14
Is made of transparent glass, and a document is placed thereon.

The reflecting plate 15 directs the light emitted from the rare gas discharge lamp 11 to the document placing surface 14.

The case 15 houses the above-mentioned components.

Thus, the rare gas discharge lamp 11 and the light receiving means 12 and the document placing surface 14 relatively scan each other. That is, as one or both of them move in the opposite direction, the light receiving means 12 sequentially receives the reflected light from the document surface in a direction perpendicular to the moving direction. The image reading apparatus according to the present embodiment is applicable to OA equipment such as a copying machine, an image scanner, and a facsimile.

FIG. 22 is a conceptual sectional view showing a backlight device for a liquid crystal display for an in-vehicle instrument as a second embodiment of the lighting device of the present invention.

In the figure, 21 is a rare gas discharge lamp, 2
2 is a light guide, and 23 is a liquid crystal display.

The noble gas discharge lamp 21 is shown in FIGS.
Are basically the same as those shown in FIG. Therefore, the same parts as those in FIGS. 1 to 4 are denoted by the same reference numerals.

The light guide 22 is made of a transparent acrylic resin plate. The width of the end face of the light guide 22 is substantially equal to the width of the light guide opening 5 of the rare gas discharge lamp 21. Are placed directly opposite to and close to.

The liquid crystal display 23 is disposed on the front of the light guide 22.

[0189] Although not shown, the light guide 22 and the rare gas discharge lamp 21 are formed by supporting the end surfaces of the light guide 15 at both side edges of the reflector surrounding the rare gas discharge lamp. It is configured to be held in the positional relationship of

Since the rare gas discharge lamp does not use mercury, which has a large environmental load, as described above, the liquid crystal display device of the present embodiment replaces the fluorescent lamp in which the conventional mercury is sealed with a liquid crystal for an in-vehicle instrument. It is suitable as a display device.

[0191]

According to each of the first to eighth aspects of the present invention, an elongated light-transmissive discharge vessel in which a discharge medium containing a rare gas containing xenon as a main component is sealed is disposed along the longitudinal direction of the outer surface of the discharge vessel. A pair of external electrodes arranged in the longitudinal direction, at least in a part of the region in the longitudinal direction, opposing side edges respectively form an uneven portion, and the other uneven portion corresponds to the protrusion of one uneven portion. Since the concave portions of the portions are arranged so as to face each other, it is possible to provide a rare gas discharge lamp in which the luminance distribution in the longitudinal direction of the translucent discharge vessel is controlled as desired.

According to the second aspect of the present invention, in addition, the opposite side edge between the pair of external electrodes is adjacent to the projection of the uneven portion of one of the external electrodes and the concave portion of the other external electrode facing the projection. The shortest distance between the protruding portion and the first electrode is defined as a first inter-electrode distance,
When the shortest distance between the directly-facing protrusion and the recess is defined as the second inter-electrode distance, the first inter-electrode distance is smaller than the second inter-electrode distance. It is possible to provide a rare gas discharge lamp in which the discharge is attracted around the center, and the discharge spreads out from the periphery along the convex portion, and as a result, the brightness distribution is leveled in the region where the uneven portion is formed. .

According to the third aspect of the present invention, the distance between the pair of external electrodes in at least one end region is smaller than the distance between the first electrodes in the central region. A rare gas discharge lamp in which the uniformity of the luminance distribution in the longitudinal direction is improved can be provided.

According to the fourth aspect of the present invention, in addition to the above, at least one end region along the longitudinal direction of the translucent discharge vessel, the opposing side edges of the pair of external electrodes are linear, and the central region is formed. Since the inter-electrode distance is smaller than the first inter-electrode distance in the above, a rare gas discharge lamp having a relatively good uniformity over the entire length of the translucent discharge vessel in the longitudinal direction can be provided.

According to the fifth aspect of the present invention, in addition to the above, a pair of external electrodes are provided with a pitch of 10 to 40 mm at the concave and convex portions on the opposite side edges along the longitudinal direction of the light-transmitting discharge vessel, so that the brightness is leveled. It is possible to provide a rare gas discharge lamp having a pitch suitable for the formation of a gas and having a desired luminance distribution set in the longitudinal direction of the translucent discharge vessel.

According to the invention of claim 6, in addition to the above, the pitch of the pair of external electrodes is 15 to 30 mm at the concavo-convex portions on the opposite side edges along the longitudinal direction of the light-transmitting discharge vessel, so that the brightness is leveled. It is possible to provide a rare gas discharge lamp having a pitch optimal for the formation of the gas and having a desired luminance distribution set in the longitudinal direction of the translucent discharge vessel.

According to the seventh aspect of the present invention, in addition, the pitch of the pair of external electrodes is changed in the longitudinal direction of the concave and convex portions on the opposite side edges along the longitudinal direction of the light-transmitting discharge vessel. In addition, it is possible to provide a rare gas discharge lamp in which the luminance distribution in the longitudinal direction of the translucent discharge vessel is finely controlled.

According to the eighth aspect of the present invention, in addition to the above, the pitch of the pair of external electrodes is relatively large in the central region in the longitudinal direction. By being large and relatively small in at least one end region, it is possible to provide a rare gas discharge lamp in which the uniformity of the luminance distribution in the longitudinal direction of the translucent discharge vessel is improved.

According to the ninth aspect of the present invention, the elongated light-transmitting discharge vessel in which a discharge medium containing a rare gas containing xenon as a main component is sealed is disposed so as to face each other along the longitudinal direction of the outer surface of the discharge vessel. A pair of external electrodes, the distance between the electrodes in at least one end region in the longitudinal direction is set to be smaller than the distance between the electrodes in the central region, the uniformity of the luminance distribution in the longitudinal direction of the translucent discharge vessel. An improved rare gas discharge lamp can be provided.

According to the tenth aspect, it is possible to provide a lighting device having the effects of the first to ninth aspects.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a first embodiment of a rare gas discharge lamp of the present invention.

FIG. 2 is an enlarged cross-sectional view of the same.

FIG. 3 is a development view centering on a light guide opening of a pair of external electrodes.

FIG. 4 is a development view centering on a non-light guide opening of a pair of external electrodes.

FIG. 5 is a graph showing a luminance distribution in the first embodiment of the rare gas discharge lamp of the present invention.

FIG. 6 is a partially cutaway rear view showing a second embodiment of the rare gas discharge lamp of the present invention.

FIG. 7 is a partially cutaway development view centered on a light guide opening of a pair of external electrodes.

FIG. 8 is a partially cutaway development view centered on a non-light-guiding opening of a pair of external electrodes.

FIG. 9 is an enlarged sectional view of the external electrode structure.

FIG. 10 is a graph showing a luminance distribution in the second embodiment of the rare gas discharge lamp of the present invention.

FIG. 11 is a partially cutaway rear view showing a third embodiment of the rare gas discharge lamp of the present invention.

FIG. 12 is a partially cutaway development view of the pair of external electrodes centered on the light guide opening.

FIG. 13 is a partially cutaway development view centered on a non-light-guiding opening of a pair of external electrodes.

FIG. 14 is a graph showing a luminance distribution in the third embodiment of the rare gas discharge lamp of the present invention.

FIG. 15 is a graph showing a luminance distribution in a comparative example.

FIG. 16 is a rear view showing a fourth embodiment of the rare gas discharge lamp of the present invention.

FIG. 17 is a rear view showing a fifth embodiment of the rare gas discharge lamp of the present invention.

FIG. 18 is a rear view showing a sixth embodiment of the rare gas discharge lamp of the present invention.

FIG. 19 is an enlarged cross-sectional view of the same central region in the longitudinal direction.

FIG. 20 is an enlarged cross-sectional view of the same end region in the longitudinal direction.

FIG. 21 is a conceptual cross-sectional view showing an image reading device as a first embodiment of the illumination device of the present invention.

FIG. 22 is a conceptual cross-sectional view showing a backlight device for a liquid crystal display for an in-vehicle instrument as a second embodiment of the lighting device of the present invention.

FIG. 23 is a rear view showing a first conventional rare gas discharge lamp.

FIG. 24 is an enlarged cross-sectional view of a plane orthogonal to the tube axis.

FIG. 25 is a development view of a light-transmitting discharge vessel and a pair of external electrodes in a second conventional rare gas discharge lamp.

FIG. 26 is centered on a light guide opening of an external electrode in a trial production example in which convex portions of convex and concave portions on opposing side edges of a pair of external electrodes are directly opposed as in the second conventional technique. Development

FIG. 27 is a development view centering on the non-light guide opening of the external electrode.

FIG. 28 is a graph showing a luminance distribution in the prototype example shown in FIGS. 26 and 27;

[Explanation of symbols]

 5A: external electrode 5Aa: uneven portion 5Aa1: uneven portion (of first region) 5Aa2: uneven portion (of second region) 5Ab: linear portion 5Ac: external lead wire connecting portion 5B: external electrode 5Ba ... Uneven portion 5Ba... Uneven portion (in first region) 5Ba... Uneven portion (in second region) 5Bb... Linear portion 5Bc... External lead wire connection portion 8. Opening for light p1 ... convex part p2 ... convex part c1 ... concave part c2 ... concave part R1 ... first area R2 ... second area x1 ... first electrode distance x2 ... first electrode distance y1 ... second Distance between electrodes y2: distance between second electrodes

Claims (10)

[Claims] 1. An elongated light-transmissive discharge vessel; a discharge medium mainly containing a rare gas containing xenon sealed in the light-transmissive discharge vessel; and a fluorescent light disposed on the inner surface side of the light-transmissive discharge vessel. A body layer; opposed along the longitudinal direction of the light-transmitting discharge vessel, and at least a part of the region in the longitudinal direction, opposed side edges each form an uneven portion; A pair of external electrodes disposed on the outer surface of the light-transmitting discharge vessel such that the concave portion of the other concavo-convex portion faces the portion; and a light-transmitting discharge vessel between the pair of external electrodes. A rare gas discharge lamp comprising: a light guide opening formed; 2. A method according to claim 1, wherein the opposite side edges forming the uneven portions of the pair of external electrodes include a convex portion of the uneven portion of one external electrode and a concave portion of the uneven portion of the other external electrode directly opposed to the convex portion. When the shortest distance between the adjacent convex portions is the first inter-electrode distance and the shortest distance between the directly facing convex portion and the concave portion is the second inter-electrode distance, the first inter-electrode distance is smaller. The rare gas discharge lamp according to claim 1, wherein is smaller than the distance between the second electrodes. 3. A pair of external electrodes in at least one end region along the longitudinal direction of the translucent discharge vessel, wherein a distance between the electrodes is smaller than a distance between the first electrodes in the central region. Item 7. A rare gas discharge lamp according to item 2. 4. An at least one end region along the longitudinal direction of the light-transmitting discharge vessel has a straight opposing side edge and a smaller inter-electrode distance than a first inter-electrode distance in a central region. The rare gas discharge lamp according to claim 2 or 3, wherein: 5. A pair of external electrodes, wherein a pitch of concavo-convex portions on opposing side edges along a longitudinal direction of the light-transmitting discharge vessel is 10 to 4.
5. The rare gas discharge lamp according to claim 1, wherein the diameter is 0 mm. 6. A pair of external electrodes having a pitch of 15 to 3 at the concavo-convex portions on opposing side edges along the longitudinal direction of the translucent discharge vessel.
The rare gas discharge lamp according to any one of claims 1 to 5, wherein the diameter is 0 mm. 7. A pair of external electrodes, wherein the pitch of the concavo-convex portions on the opposite side edges along the longitudinal direction of the translucent discharge vessel changes along the longitudinal direction. 7. The rare gas discharge lamp according to any one of items 6 to 6. 8. A pair of external electrodes, wherein the pitch of the concavo-convex portions of the opposing side edges along the longitudinal direction of the translucent discharge vessel is relatively large in the central region in the longitudinal direction, and at least one end portion of the outer electrodes The rare gas discharge lamp according to claim 1, wherein the rare gas discharge lamp is relatively small in a region. 9. An elongated light-transmitting discharge vessel; a discharge medium mainly composed of a rare gas containing xenon sealed in the light-transmitting discharge vessel; and a fluorescent light disposed on the inner surface side of the light-transmitting discharge vessel. A body layer; a light-transmitting discharge vessel which is spaced apart and opposed along the longitudinal direction, and wherein a distance between the electrodes in at least one end region along the longitudinal direction is set to be smaller than a distance between the electrodes in the central region; A rare gas, comprising: a pair of external electrodes provided on the outer surface of the transparent discharge vessel; and a light guide opening formed in the translucent discharge vessel between the pair of external electrodes. Discharge lamp. 10. A lighting device comprising: a lighting device main body; and the rare gas discharge lamp according to claim 1 disposed in the lighting device main body.