JPH10275593A - Multi-tube fluorescent lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mechanical strength, improve the rising characteristic of luminous flux, and restrict the lowering of luminance due to a temperature rise. SOLUTION: Both ends of a glass outer tube 2, which surrounds a light emitting tube 1 with a little space, are fixed to positions near each end of the light emitting tube 1 by glass welding, and the light emitting tube and the glass outer tube are directly and indirectly made to come close to each other (for fixation, contact, proximity at a position opposite to a discharge space part of the light emitting tube. Fixation of the light emitting tube 1 and the glass outer tube 2 is thereby facilitated, and inside of the glass tube 2 is maintained at a high degree of air-tightness, and the flowing heating medium can be sealed in the inner space. In the case where the light emitting tube 1 and the glass outer tube 2 are fixed to each other or made to contact with each other, heat generated in the light emitting tube is discharged outside through a heat conductive means so as to prevent the generation of temperature rise of the light emitting tube 1, and luminance of the light emitting tube after stable lighting is maintained at a high degree. Furthermore, since the vibration generated in the light emitting tube 1 is hindered by the glass outer tube 2, breakdown of the light emitting tube 1 due to the excessive vibration can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tube fluorescent lamp in which a glass outer tube is provided around an arc tube, and a lighting device using the same.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view of a conventional double tube fluorescent lamp.

The above prior art is described in Japanese Utility Model Publication No. 4-52932. In the figure, 101
Is an outer tube made of glass, and 104 is a hermetically sealed envelope tube made of glass. The outer tube 101, the envelope tube 104, and holding members 106, 106 described later form a double tube structure. The outer tube 101 surrounds the envelope tube 104 such that a space S surrounding the outer wall of the envelope tube 104 is formed at an interval of about 1 to 10 mm between the inner wall of the outer tube 101 and the outer wall of the envelope tube 104, Both of them are held at both ends by heat insulating holding members 106, 106. Further, the ends 141 of the sealing tube 104 are respectively held by the holding members 10.
6 and 106, and these holding materials 1
06 and 106 are ends 111 and 11 of the outer tube 101, respectively.
1 is hermetically fitted to hermetically seal the outer tube 101, and a double tube structure is formed by the envelope tube 104, the outer tube 101, and the holding members 106, 106. It is stated that the space S is preferably reduced in pressure and evacuated, and in this case, the heat insulation between the envelope tube 104 and the outer tube 101 can be further improved. A fluorescent film 1 is provided on the inner wall surface of the envelope tube 104.
42, the total length L of the lamp is 120 mm or less, the power consumption is 2 W or less, and the outer diameter d of the envelope tube 104 is 6 mm or less. The outer diameter D of the outer tube 101 is preferably set to 20 mm or less. The double tube fluorescent lamp is used for a liquid crystal backlight.

In the drawing, reference numeral 102 denotes a filament electrode, 1
03 is a lead wire and 105 is a mercury-impregnated alloy.

According to the above-mentioned prior art, power consumption is 2
Even when the temperature is less than W, since the lamp is a double tube, a required temperature rise can be obtained at the time of starting even in a relatively low-temperature atmosphere, so that the luminous flux rise is superior to that of a fluorescent lamp having no outer tube.

[0006]

However, in the above prior art, the sealing tube 104 has the outer tube 1 only at both ends.
01, it has low mechanical strength. For example, when used in a liquid crystal backlight, the following description will be given. If the backlight is accidentally dropped or the lid of an OA device incorporating the backlight is violently It was found that the shock at the time of closing caused a rotational moment or the like to act on the arc tube, and the arc tube was damaged due to excessive vibration.

Further, in the prior art, the luminous flux rising characteristics are improved, but the luminous tube is kept warm by the outer tube even after the luminous flux rises, so that the mercury vapor pressure in the luminous tube becomes too high and the luminance is reduced. There is also a problem that shows a tendency of saturation.

The present invention provides a multi-tube fluorescent lamp which suppresses excessive vibration of an arc tube and improves mechanical strength, and is particularly suitable for a compact illumination device such as a liquid crystal backlight, and an illumination device using the same. The primary purpose is to provide.

The present invention provides a multi-tube fluorescent lamp in which the luminous flux rising characteristics are improved, and an excessive rise in the temperature of the arc tube during stable lighting is prevented to prevent a decrease in luminance, and a lighting device using the same. This is a second object.

A third object of the present invention is to provide a multi-tube fluorescent lamp in which the coolest portion is formed at the end of the arc tube to suppress the consumption of mercury due to discharge, and an illumination device using the same. .

[0011]

According to the first aspect of the present invention, there is provided a multi-tube fluorescent lamp having an elongated airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, and an inner surface of the glass bulb. An arc tube comprising a phosphor layer and a discharge medium sealed in a glass bulb; an arc tube surrounding the arc tube with a gap formed around the arc tube and both ends fixed to both ends of a glass bulb of the arc tube; And a glass outer tube which is directly or indirectly closer to another portion than the other portion at a position facing the discharge space of the arc tube.

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

First, the glass bulb will be described.

The glass bulb is preferably made of soft glass such as soda lime glass or lead glass, but may be made of hard glass such as borosilicate glass if necessary. The cross-sectional shape is usually circular, but if necessary, it may be non-circular, for example, elliptical or any other cross-sectional shape. Furthermore, the shape in the longitudinal direction is a shape bent into any desired shape such as a straight pipe, a bent shape such as an annular shape or a semicircle, or a bent shape such as an L shape, a U shape, or a W shape. To allow. Note that the term “bend” refers to bending at a relatively small radius. In addition, the term “composition” means simply bending including bending.

The use of the multi-tube fluorescent lamp of the present invention is not limited, since it can be applied to a fluorescent lamp for any use and exhibit the expected effects. Therefore, the outer diameter and the overall length of the glass bulb constituting the arc tube can be set arbitrarily. However, the present invention exerts particularly remarkable functions and effects in a relatively elongated and compact fluorescent lamp used for reading a backlight such as a liquid crystal, reading OA equipment, and illuminating an instrument mounted on a vehicle. In the case of such a relatively elongated and compact fluorescent lamp, in the present invention, the arc tube generally has an outer diameter of 6 mm.
mm or less, preferably 4 mm or less, and most preferably 3 mm or less. The wall thickness is generally 1 mm or less, preferably 0.1 to 0.7 mm, and most preferably about 0.3 mm.
Further, the overall length may be generally an arbitrary length,
Preferably 30-400 mm, optimally 50-250 m
m.

Next, the electrodes will be described.

As described above, the application of the electrode as a fluorescent lamp is not limited, and therefore, an electrode of an appropriate type, either a cold cathode or a hot cathode, can be selected according to the application. However, when applying the present invention to a relatively elongated and compact fluorescent lamp, it is generally better to use a cold cathode, but it can be understood that the hot cathode is not excluded from the properties of the present invention. Would.

The phosphor layer will be described.

The phosphor layer may be formed directly on the inner surface of the glass bulb, or may be formed indirectly via, for example, a protective film. The phosphor to be used may be any desired one according to the application. For example, in the case of a reading fluorescent lamp, a rare earth phosphate phosphor (La) is used.
PO _4: Ce ₃ ^+, single color emission phosphor or phosphor containing this as Tb ₃ ^+), if the backlight and multi-tube type fluorescent lamp for vehicle instrument lighting, three-wavelength emission type fluorescent material or a A phosphor having a white emission color such as a halophosphate phosphor can be used.

The discharge medium will be described.

As the discharge medium, mercury and a rare gas such as neon or argon are often used. However, without using mercury, only xenon gas is used as a rare gas.
The phosphor can be excited by ultraviolet light emitted by xenon gas discharge.

Furthermore, ultraviolet rays having respective wavelengths may be generated by enclosing xenon gas and mercury to generate both xenon gas discharge and mercury vapor discharge.

Further, when the rare gas enclosed with mercury is a simple gas of argon, neon or krypton, or a mixed gas of argon and neon, argon, neon and helium, the startability can be improved by the Penning effect. can get.

The mercury may directly enclose pure mercury,
It can be encapsulated in any desired form such as in the form of amalgam.

The glass outer tube will be described.

The glass outer tube is preferably made of glass of the same material as the glass bulb, but a different glass material may be used as long as the workability with the glass bulb is not hindered.

As described in the description of the arc tube, the present invention is not limited to a specific use. Therefore, the glass outer tube can be set to a desired size according to the use of the fluorescent lamp. In lamps, the glass outer tube generally has an outer diameter of 8 mm or less, preferably 6 mm or less.
mm or less, optimally 4 mm or less. The wall thickness is
Generally, 1 mm or less, preferably 0.1 to 0.7 m
m, optimally about 0.3 mm. Furthermore, the total length is
Generally, the length may be any length, but preferably 30 to
400 mm, optimally 50-250 mm.

The glass outer tube is generally fixed to the arc tube by glass welding in a concentric positional relationship. However, it is sufficient that a gap is formed around the arc tube by the glass outer tube. You can be mindful.

In the present invention, an arbitrary number of glass outer tubes can be used, for example, concentrically. further,
The inside of the glass outer tube may be evacuated to a reduced pressure atmosphere, or the degree of vacuum may be increased to a so-called high vacuum of 100 Pa or less. Furthermore, after a high vacuum state is established, an evaporable metal such as mercury and / or a fluid heat medium such as a rare gas can be sealed.

The fixing of the glass outer bulb and the glass bulb of the arc tube is performed by glass welding. In this case, both or one of the two glasses is melted and fixed. The glass may be fused by interposing a glass material having a value for welding. Thus, it becomes easy to make the space between the glass outer tube and the glass bulb airtight by the glass welding. When the space between the two is made airtight, the above-mentioned fluid heat medium can be sealed in the space to contribute to the temperature control of the arc tube.

The positional relationship between the outer glass tube and the arc tube will be described.

In the present invention, the discharge space of the arc tube means a space between the tips of the electrodes.

[0033] The term "directly or indirectly approaching the arc tube at a position facing the discharge space portion of the arc tube" means that both are fixed by welding or bonding means or are in contact with each other. Or a state in which the arc tube and the glass outer tube are close to each other with a slight gap formed so that vibration can be performed only within an allowable range. Here, the allowable range refers to a range in which the arc tube is not damaged by large amplitude vibration.

[0034] The term "fixed" means that the material is fixed so as not to be easily separated directly or via a spacer.

Next, the term "contact" means that all or a part of the section of the arc tube and the outer glass tube facing the discharge space is in direct or indirect contact with, but is not fixed to, the whole. The term “direct contact” refers to a state in which the outer surface of the arc tube and the inner surface of the glass outer tube are in direct contact. The contact may be made, for example, in a state in which one side of the straight tube portion of the arc tube is in line contact with one side of the inner surface of the glass outer tube, or a portion of the arc tube or the glass outer tube is protruding, Include a state in which the lamp is in contact with the partner, a state in which the arc tube or the glass outer tube is curved, and the curved portion is in contact with the partner. The term “indirect contact” means that the arc tube and the glass outer tube are clearly separated from each other, but another member, that is, a spacer is interposed between the arc tube and the glass outer tube. State.

Further, the proximity means that it does not hinder the insertion of the arc tube into the glass outer tube. However, if a vibration is caused so as to damage the arc tube, it is directly or indirectly regulated by the glass outer tube. This is a positional relationship in which the arc tube cannot vibrate because of such a configuration. The term “direct” includes, for example, a state in which the projection toward the arc tube is formed at an interval of 120 ° at an intermediate portion of the glass outer tube, or a circumferential concave portion is formed to restrict the movement of the arc tube. Indirect means that the interposition of the spacer is allowed.

As the spacer for the above-mentioned fixing, contacting or approaching, for example, a spiral body wound around the arc tube, a ring-shaped object fitted to the arc tube, or interposition between the arc tube and the outer glass tube along their longitudinal direction. A striated body or the like can be used. Further, the material of the spacer may be either non-thermally conductive or thermally conductive. The former is effective for improving the vibration resistance. The latter is effective for vibration resistance and suppression of excessive rise in temperature of the arc tube.

When the glass outer tube is deformed and brought into contact with or close to the arc tube, the glass outer tube may be processed in advance, or the glass outer tube may be heated and softened after fixing the arc tube and the glass outer tube at both ends. It may be molded.

In bending the multi-tube fluorescent lamp of the present invention into an arbitrary shape, first, a straight tube-type multi-tube fluorescent lamp is manufactured, and then the fluorescent lamp is heated and softened and then bent. In the above, since the arc tube is easily brought into contact with the glass outer tube, the arc tube or the glass outer tube may not be specially processed for contact. However, if necessary, the arc tube and the outer glass tube can be separated from each other at the bent portion, for example, the bent portion.

Next, the operation of the present invention will be described.

Since the arc tube is surrounded by the outer glass tube, the discharge space is kept warm and the luminous flux (luminance) rising characteristics are improved, which is the same as the prior art. An effect unique to the present invention is achieved.

Since the glass outer tube is fixed to the vicinity of the end of the arc tube by glass welding, the fixing is easy and
The space formed between the outer glass tube and the light emitting space can be made highly airtight, so that the space can be evacuated or evacuated as required, or a fluid heat medium can be enclosed. it can.

If the approach between the arc tube and the glass outer tube is fixed or in contact, the heat conduction means is formed between the two tubes by itself, so that the temperature of the arc tube rises excessively. It is possible to suppress the luminance of the arc tube after the stable lighting to a high value after the suppression.

Further, the heat retaining action of the space can be arbitrarily adjusted. In other words, the space can be adjusted so that a fluid heat medium is sealed therein so as to exhibit a moderately suppressed heat retaining action.

As described above, according to the present invention, it is possible to improve the luminous flux (luminance) rising characteristic, to maintain the luminance at a high value by setting the mercury vapor pressure to a desired value during stable lighting, and to further improve the vibration. Means that the arc tube can be prevented from being damaged.

By forming a circumferentially curved portion near one or both ends of the arc tube and the glass outer tube, a difference in thermal expansion between the arc tube and the glass outer tube due to a rise in temperature during lighting is obtained. The occurrence of cracks in the arc tube due to the above can be prevented. The peripheral curved portion may be either a concave concave portion or a convex convex portion. Since the occurrence of cracks is suppressed by absorbing the difference in the coefficient of thermal expansion by the circumferentially curved portion, breakage of the arc tube is reduced.

Further, even when the arc tube and the glass tube are fixed or in contact with each other directly or via a thermally conductive spacer at a position facing the discharge space, the outside air temperature acts on the arc tube. In addition, it is possible to suppress the temperature rise of the arc tube due to the self-heating of the discharge. For this reason,
Since the temperature of the arc tube can be maintained at an optimum mercury vapor pressure or a vapor pressure close thereto, a decrease in luminous flux during stable lighting can be eliminated or reduced. In this case, it is not necessary to enclose the fluid heat medium in the space between the arc tube and the outer glass tube, or the encapsulation may be used so that both of the above actions are used.

In the case where the arc tube and the outer glass tube are provided with a curved portion, if both are separated from each other in the curved portion, a temperature difference occurs between the two when the multi-tube fluorescent lamp is turned on. No distortion is caused by the difference in expansion and contraction.

According to a second aspect of the present invention, in the multi-tube fluorescent lamp according to the first aspect, the arc tube has an outer diameter of 6 mm or less.
The outer diameter of the glass outer tube is 8 mm or less, and the thickness of the glass outer tube is 1 mm or less.

The present invention specifies the size of a general arc tube and a glass outer tube as an elongated and compact fluorescent lamp which is used for a backlight such as a liquid crystal, reading, and illumination of a vehicle instrument.

According to a third aspect of the present invention, in the multiple tube fluorescent lamp according to the first or second aspect, the arc tube has an outer diameter of 4 m.
m or less, wall thickness 0.1-0.7mm, total length 30-30
0 mm; the outer glass tube has an outer diameter of 6 mm or less, a wall thickness of 0.1 to 0.7 mm, and an overall length of 30 to 400 mm.

The present invention defines a more preferable range as compared with claim 2.

According to a fourth aspect of the present invention, in the multi-tube fluorescent lamp according to any one of the first to third aspects, the arc tube has a curved middle portion and is in contact with the inner surface of the glass outer tube. It is characterized by.

According to the present invention, since the middle portion of the arc tube comes into contact with the inner surface of the glass outer tube, the vibration is suppressed by the glass outer tube even if the arc tube receives an impact, so that the arc tube is hardly damaged.

According to a fifth aspect of the present invention, there is provided the multi-tube fluorescent lamp according to any one of the first to third aspects, wherein the luminous tube is provided outside the glass with a part of the peripheral surface being in contact with the inner surface of the outer glass tube. It is characterized by being eccentrically fixed to the pipe.

In the present invention, since the arc tube is in contact with the inner surface of the glass outer tube over its entire length, the effect of suppressing vibration is great. Further, since the heat of the arc tube can be radiated to the outside through the glass outer tube via the contact portion, there is also an effect of suppressing an excessive rise in the temperature of the arc tube.

According to a sixth aspect of the present invention, in the multi-tube fluorescent lamp according to any one of the first to third aspects, the glass outer tube has a projection which is in contact with the arc tube on the inner surface at the intermediate portion. It is characterized by. In addition, it is possible to perform an action of suppressing an excessive rise in the temperature of the arc tube.

In the present invention, any number of projections is allowed, and even if there is one, vibration of the arc tube is prevented, so that damage to the arc tube is prevented.

According to a seventh aspect of the present invention, in the multi-tube fluorescent lamp according to any one of the first to third aspects, the glass outer tube is provided with projections approaching the three arc tubes at intervals of about 120 °. It is characterized by having.

In the present invention, since the degree of freedom of the arc tube in the plane orthogonal to the axis of the glass outer tube can be almost eliminated, even if the arc tube is not in contact with the projection, the arc tube can be used. Damage can be prevented.

According to an eighth aspect of the present invention, in the multi-tube fluorescent lamp according to any one of the first to third aspects, the outer glass tube and the arc tube are close to each other due to the spacer interposed therebetween. Features.

In the present invention, the arc tube and the outer glass tube need not be processed. It is advisable to use a material having a high light transmittance for the spacer or reduce the size of the spacer so that the amount of light is not reduced by the spacer. If the spacer is formed of a thermally conductive material, an excessive rise in the temperature of the arc tube can be suppressed.

According to a ninth aspect of the present invention, there is provided a multi-tube fluorescent lamp.
An arc tube comprising an elongated airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge medium sealed in the glass bulb; A glass outer tube surrounding the tube with a gap formed around it and having both ends fixed by glass welding near both ends of the glass bulb of the light emitting tube; and a light emitting tube at a position facing the discharge space of the light emitting tube; A heat conducting means for connecting the outer glass tube in a heat conducting relationship.

As the heat conducting means, means such as direct welding of the arc tube and the outer glass tube, indirect fixing or contact through a spacer made of a heat conductive material, or the like can be employed. As a spacer made of a heat conductive material,
Metal or a thermally conductive synthetic resin can be used.

The heat conducting means may be provided continuously along the axial direction of the arc tube as long as it is located at a position facing the discharge space of the arc tube. Further, the heat conducting means may be partially provided at one or a plurality of positions. Further, the heat conducting means may be provided over the entire circumference with respect to the axis of the arc tube, or may be provided at a part of the circumference.

As a specific example of the above, for example, a spiral member made of a metal wire is interposed in a space between the arc tube and the glass outer tube at a part of the position facing the discharge space of the arc tube or over the entire length. be able to. In this case, the both ends of the spiral member are airtightly led out of the glass outer tube to the outside and grounded to further reduce high frequency noise. Also, high-frequency noise can be reduced by not leading out both ends of the spiral member, or even by leading it out, but not directly grounding, but by bringing the grounded metal member close to the glass outer tube.

As another specific embodiment, a straight metal wire may be interposed between the arc tube and the outer glass tube.

Further, a thermally conductive insulating member may be used instead of the above-mentioned metal wire.

Thus, in the present invention, the arc tube and the outer glass tube are connected in a heat conducting relationship by the heat conducting means at a position facing the discharge space of the arc tube.
The temperature of the arc tube is controlled by the outside air of the glass outer tube, and it is possible to suppress the temperature of the arc tube from excessively rising due to self-heating caused by discharge.

Therefore, by setting the mercury vapor pressure to the optimum or optimum direction, the brightness of the multi-tube fluorescent lamp can be maintained at a high value during stable lighting.

Further, since the arc tube is held by the glass outer tube via the heat conducting means, the arc tube is strengthened against vibration, and the fluorescent lamp is hardly damaged.

Further, when the arc tube and the glass outer tube are fixed by heat conduction means, the fluorescent lamp becomes strong against external stress.

A multi-tube fluorescent lamp according to a tenth aspect of the present invention is the multi-tube fluorescent lamp according to the ninth aspect, wherein the heat conducting means is a heat conductive spacer.

As the heat conductive spacer, for example, a ring, a spiral body, a striated body made of metal or a heat conductive synthetic resin is allowed. As the heat conductive synthetic resin, for example, a silicone resin is allowed.

In the present invention, since the luminous body and the glass outer tube are in contact with each other through the heat conductive spacer, the outside air of the glass outer tube acts on the luminous tube via the heat conductive spacer to form the luminous tube. Since an excessive rise in temperature can be prevented, the luminance of the multi-tube fluorescent lamp during stable lighting can be maintained at a high value. In addition, since the arc tube is protected against vibration by the heat conductive spacer, the arc tube is less likely to be damaged even if it receives an impact.

According to an eleventh aspect of the present invention, in the multi-tube fluorescent lamp according to the ninth aspect, the heat conducting means is a welded portion formed by welding the arc tube and the outer glass tube to each other. It is characterized by being.

In the present invention, since the arc tube and the outer glass tube are directly welded to each other to constitute the heat conducting means, the temperature of the arc tube can be prevented from excessively rising, and the production is easy. In addition, stress generated by changes in the ambient temperature and the temperature of the arc tube can be dispersed, and the glass outer tube and the arc tube are integrated at a position facing the discharge space against vibrations applied from the outside. , The intensity of the fluorescent lamp is significantly improved.

According to a twelfth aspect of the invention, there is provided a multi-tube fluorescent lamp according to the ninth aspect, wherein the heat conducting means is formed by direct heat conductive contact between the arc tube and the outer glass tube. It is characterized in that it is a contacted part.

In the present invention, heat is conducted between the arc tube and the outer glass tube by contact between the arc tube and the glass outer tube. Prevent damage.

A multi-tube fluorescent lamp according to the invention of claim 13 is the multi-tube fluorescent lamp according to any one of claims 9 to 12, wherein the luminous tube is provided between a plurality of linear portions and between the linear portions. Comprising at least one intervening bend; the outer glass tube being bent to conform to the shape of the arc tube; the heat conducting means being located at the bend of the arc tube and the outer glass tube; Features.

In the present invention, the heat conducting means is welding,
Any of a contact and a heat conductive spacer etc. may be sufficient.

Thus, since the heat conducting means is located at the bent portions of the arc tube and the glass outer tube, the strength of the bent portion can be improved.

When the heat conducting means is welding or contact, both ends of the glass outer tube are glass-welded to the arc tube in advance, or both are inserted coaxially, and then the portion to be bent is heated. By softening and bending, the arc tube and the outer glass tube can be easily brought into contact at the bent portion. Further, by heating the bent portion, both can be welded. By fixing the glass outer tube to the arc tube and exhausting the inside of the glass outer tube, contact or welding can be further facilitated.

According to a fourteenth aspect of the present invention, there is provided the multi-tube fluorescent lamp according to any one of the ninth to thirteenth aspects, wherein a fluid heat medium is provided in a space between the arc tube and the outer glass tube. It is characterized by being enclosed.

The fluid heat medium refers to a heat medium that forms a gas phase or a liquid phase. The heat medium refers to a medium that can conduct and move heat. For example, the substance in the gas phase may be air or a rare gas at normal pressure or appropriately reduced pressure, or may be an evaporable metal such as mercury which exhibits a gas phase at the operating temperature of the fluorescent lamp.

Thus, in the present invention, since the fluid heat medium is sealed in the glass outer tube, the light is emitted by the fluid heat medium in addition to the heat conducting means acting between the arc tube and the glass outer tube. Excessive temperature rise of the tube can be suppressed.

A multi-tube fluorescent lamp according to a fifteenth aspect of the present invention comprises an elongated airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a glass bulb. An arc tube comprising a discharge medium encapsulated therein; glass surrounding the arc tube with a gap formed therearound and having both ends opposed to the end of the arc tube and the electrode front surface It is characterized by comprising: a glass outer tube fixed by welding; and a fluid heat medium sealed in the glass outer tube.

In the present invention, the front surface of the electrode is surrounded by a glass outer tube, but the end of the arc tube is exposed from the glass outer tube.

Since the end of the arc tube is not kept warm by the outer glass tube, the coolest part in the arc tube is formed at the end of the arc tube. The mercury vapor pressure near the coldest part is lower than the other parts, but since it is separated from the discharge space, the mercury vapor near the coolest part is not ionized, so mercury is injected into the glass bulb of the arc tube. Consumption is reduced. However, since the discharge space is kept warm by the glass outer tube, the luminous flux rising characteristics are improved. In addition, since the fluid heat medium is sealed in the glass outer tube, the heat of the arc tube is appropriately dissipated outside the glass outer tube by the fluid heat medium in the glass outer tube. It is suppressed on the high temperature side. Therefore, it is possible to reduce a decrease in luminance due to an excessive rise in the temperature of the arc tube during stable lighting.

The multi-tube fluorescent lamp according to the invention of claim 16 is characterized in that, in the multi-tube fluorescent lamp according to claim 14 or 15, at least a part of the fluid heat medium is an evaporable metal. .

For example, mercury or the like can be used as the evaporable metal. The entire flowable heat medium may be constituted by vapor of the evaporable metal, but a part thereof can be replaced by a rare gas or another gas.

Thus, by promoting the heat radiation of the arc tube by the vapor of the evaporable metal, the heat retaining action of the arc tube can be adjusted as desired.

The multi-tube fluorescent lamp according to the invention of claim 17 is the multi-tube fluorescent lamp according to any one of claims 14 to 16, wherein at least a part of the fluid heat medium is a rare gas. Features.

As the rare gas, helium, neon, argon, krypton, or xenon can be used alone or as a mixture. The whole of the fluid heat medium may be composed of a rare gas, but if necessary, a part thereof can be composed of vapor of evaporable metal.

Thus, by promoting the heat radiation of the arc tube by the rare gas, the heat retaining action of the arc tube can be adjusted as desired. By encapsulating the same substance as the discharge medium encapsulated in the arc tube also in the glass outer bulb, the manufacture of the multi-tube fluorescent lamp can be facilitated.

The multi-tube fluorescent lamp according to the eighteenth aspect of the present invention is an elongated airtight glass bulb having a bent portion, a pair of electrodes sealed at both ends of the glass bulb, and a fluorescent lamp formed on the inner surface side of the glass bulb. An arc tube comprising a body layer and a discharge medium encapsulated in a glass bulb; having a curved portion along the arc tube and in contact with the arc tube at the curved portion but surrounding at other portions A glass outer tube surrounding the arc tube with a gap formed therebetween and having both ends fixed near both ends of the glass bulb of the arc tube; the arc tube and the glass outer tube at a position facing the discharge space of the arc tube. Heat conducting means connected in a heat conducting relationship.

The arc tube and the outer glass tube in the bent portion may be in contact with each other as long as they are formed in a part of the bent portion in the longitudinal direction of the tube. In addition, in the circumferential direction of the pipe, it is sufficient that it is in contact with a part, but if necessary, it may be in contact with the entire circumference.

The heat conducting means is the same as described in claim 9. Therefore, the contact at the bent portion can also serve as the heat conducting means.

Thus, in the present invention, since the arc tube and the glass outer tube are in contact at their bent portions,
Cracks and breakage due to an impact applied from the outside of the multi-tube fluorescent lamp are reduced.

Further, since heat is conducted from the arc tube to the glass outer tube by the contact, the temperature rise of the arc tube during lighting is somewhat suppressed, so that the tube surface brightness can be maintained slightly higher. Furthermore, after welding both ends of the arc tube and the glass outer tube, it can be manufactured by heating and bending the glass,
Easy to manufacture.

However, it should be noted that distortion may occur in the bent portion due to a difference in expansion and contraction due to a temperature difference between the arc tube and the outer glass tube.

The multi-tube fluorescent lamp according to the nineteenth aspect of the present invention is an elongated airtight glass bulb having a bent portion, a pair of electrodes sealed at both ends of the glass bulb, and a fluorescent lamp formed on the inner surface side of the glass bulb. An arc tube including a body layer and a discharge medium sealed in a glass bulb; a curved portion along the arc tube, and a part of the inner peripheral surface of the curved portion is welded to the arc tube A glass outer tube which surrounds the arc tube with a gap around it and is fixed at both ends near both ends of the glass bulb of the arc tube; at a position facing the discharge space portion of the arc tube And a heat conducting means for connecting the arc tube and the outer glass tube in a heat conducting relationship.

The term "partially welded" in the bent part means that there is a part that is not welded in the circumferential direction, and it may be part or all in the longitudinal direction.

In order to form a welded portion, a part of the bent portion of the glass outer tube may be heated and melted at the time of bending.

Thus, in the present invention, since the arc tube and the glass outer tube are partially welded at their bent portions, the welded portion becomes the coldest portion. Therefore, when the ambient temperature is high, a decrease in luminance can be reduced.

It is relatively easy to weld a part of the bent portion.

However, distortion occurs at the welded portion due to a difference in expansion and contraction due to a temperature difference between the arc tube and the outer glass tube. However, there is no problem if the operating temperature range is 0 ° C. to a normal temperature range.

[0108] The multi-tube fluorescent lamp according to the twentieth aspect of the present invention is an elongated airtight glass bulb having a bent portion, a pair of electrodes sealed at both ends of the glass bulb, and a fluorescent lamp formed on the inner surface side of the glass bulb. An arc tube comprising a body layer and a discharge medium sealed in a glass bulb; a curved portion along the arc tube, wherein the curved portion has an inner peripheral surface welded to the arc tube over the entire circumference. A glass outer tube which surrounds the arc tube with a gap around it and is fixed at both ends near both ends of the glass bulb of the arc tube; at a position facing the discharge space portion of the arc tube And a heat conducting means for connecting the arc tube and the outer glass tube in a heat conducting relationship.

The welding over the entire circumference of the bent portion means that there is no unwelded portion in the circumferential direction, and it may be either part or all in the longitudinal direction.

In order to form a welded portion, the entire circumference of the bent portion of the glass outer tube may be melted by being strongly heated during bending.

The heat conducting means is the same as in the nineteenth aspect.

Thus, in the present invention, since the arc tube and the outer glass tube are welded over the entire circumference at the bent portion, the welded portion becomes the coldest part with good efficiency. Therefore, a wide range of ambient temperature, for example, -40 to -1
Over 00 ° C., it can be applied even when high efficiency luminance is required.

Although distortion occurs due to a difference in expansion and contraction due to a temperature difference between the arc tube and the outer glass tube, the distortion does not concentrate on a part because the welded portion extends over the entire circumference.

The lighting device according to the twenty-first aspect of the present invention is the lighting device main body;
And a multi-tube fluorescent lamp according to any one of the above.

The illumination device of the present invention is not limited in its use for the same reason as described above in which the multiple tube fluorescent lamp of the preceding claim is not limited in its application. For example, it includes lighting equipment for general lighting. However, when an elongated and compact multi-tube fluorescent lamp is used, a lighting device for general lighting may be used, but a backlight device of a display device such as a liquid crystal, an image forming device such as a copying machine, an image scanner, a facsimile, etc. Applicable to image reading devices of devices and lighting devices of in-vehicle instruments.

[0116]

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

FIG. 1 is a partially cutaway front view showing a first embodiment of a multi-tube fluorescent lamp according to the present invention.

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

In the figure, reference numeral 1 denotes an arc tube and 2 denotes an outer glass tube.

The arc tube 1 is an elongated airtight glass bulb 1
a, a pair of cold cathode electrodes 1b sealed at both ends of a glass bulb 1a, a lead wire 1c extending from the electrode 1b through an end of the glass bulb 1a, and a glass bulb 1a.
The discharge layer is composed of a rare gas mainly composed of mercury and neon as a discharge medium sealed in the phosphor layer 1d formed on the inner surface of the substrate and the glass bulb 1a. The arc tube 1 is a glass bulb 1
a has an outer diameter of 2.4 mm and a wall thickness of 0.3 mm. And
The arc tube 1 is slightly curved, and when the arc tube 1 is inserted into the glass outer tube 2 and both ends are coaxially fixed at both ends of the glass outer tube 2, the intermediate portion of the arc tube 1 is on the inner surface of the glass outer tube 2. Contact.

The outer glass tube 2 has an outer diameter of 3.6 mm and a thickness of 0.3 mm, and both ends thereof are welded to both ends of the glass bulb 1a of the luminous tube 1 in a concentric positional relationship with the luminous tube 1a. It is integrated.

The overall length of the obtained multi-tube fluorescent lamp is 200 mm.

FIG. 3 is an enlarged sectional view showing a main part of a second embodiment of a multiple tube fluorescent lamp according to the present invention.

In this embodiment, the arc tube is straight, but the arc tube is eccentrically fixed to the glass outer tube. Thus, the arc tube contacts the inner surface of the glass outer tube over substantially the entire length.

FIG. 4 is a partially cutaway front view showing a third embodiment of the multi-tube fluorescent lamp of the present invention.

In the figure, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. This embodiment differs from the first embodiment in that it forms the projections 3 _A in contact with the arc tube glass outer tube 2. That is, in the intermediate portion of the glass outer tube 2, the projection 3 can be formed by partially heating and softening the glass outer tube 2 and then pressing the glass outer tube 2 from outside with a jig.

FIG. 5 is an enlarged sectional view of a main part of a multi-tube fluorescent lamp according to a fourth embodiment of the present invention.

This embodiment is different from the above-described embodiment in that the space between the arc tube 1 and the glass outer tube 2 is made closer by interposing a spacer between the arc tube 1 and the glass outer tube 2. That is, the spiral member 3 _B after fitting made of, for example, a metal wire of about 1 to 2 turns in the middle portion of the arc tube 1, by inserting the glass outer tube 2 an arc tube 1, the glass outside the arc tube 1 It is close to the inner surface of the tube 2. In this embodiment, the light emitting tube 1 and the glass outer tube 2, may be contacted through the spiral member 3 _B, it may be close. The spiral member 3
_B may reach the entire length of the arc tube 1 and the glass outer tube 2.

FIG. 6 is an enlarged sectional view of a main part showing a fifth embodiment of a multi-tube fluorescent lamp according to the present invention.

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

In the present embodiment, three projections 3 _A1 , 3 _A2 , 3 _A3 are formed toward the arc tube 1 at 120 ° intervals in the middle of the glass outer tube 2. Each protrusion 3 _A1 , 3
_{Although A2} and _3A3 are not in contact with the arc tube 1, the gap with the arc tube 1 is small, so that the arc tube 1 is prevented from excessive vibration.

FIG. 7 is a sectional view of a liquid crystal backlight unit showing a first embodiment of the lighting device of the present invention.

In the figure, 4 is a backlight unit,
Reference numeral 5 denotes a liquid crystal display unit, and reference numeral 6 denotes a display device.

The backlight unit 4 includes a light guide 4a made of acrylic resin, a multi-tube fluorescent lamp 4b disposed on the side of the light guide 4a, and a reflector 4 disposed on the back of the light guide 4a.
c, a light control means 4d disposed in front of the light guide 4a, for example, a diffuser 4d1, a light collector 4d2, and a reflector 4 which covers the multi-tube fluorescent lamp 4b and opens toward the light guide 4a.
e and a case 4f for housing the above components. In addition, each opening edge 4e1, 4 of the reflection plate 4e
e2 is designed so that light is effectively introduced into the light guide with the end of the light guide 4a sandwiched from above and below.

The liquid crystal display unit 5 includes the backlight unit 4
It is arranged in front of the.

The backlight unit 4 and the display unit 5 constitute a display device 6.

Regarding the operation of the backlight unit,
Even if the multi-tube fluorescent lamp 4b is used as a light source, the light source is essentially the same, and the operation of the backlight unit is well-known, so that the description is omitted.

FIG. 8 is a conceptual sectional view of a reading device showing a second embodiment of the illumination device of the present invention.

In the figure, 7 is a reading device, 7a is a multi-tube fluorescent lamp, 7b is light receiving means, 7c is a signal processing device,
7d is a document placing surface, 7e is a case for storing the above-mentioned components, and 7f is a reflecting mirror.

The reader is applicable to OA equipment such as a copying machine, an image scanner, and a facsimile.

The operation of the reading device is essentially the same as that of a single tube fluorescent lamp even when the multi-tube fluorescent lamp 4b is used as a light source, and the operation of the reading device is well known, so that the description is omitted.

FIG. 10 is a front view showing a sixth embodiment of a multi-tube fluorescent lamp according to the present invention.

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

In the present embodiment, the middle portion is bent at a right angle to form an L-shape (in the figure, an inverted L-shape).

The arc tube 1 and the outer glass tube 2 are glass-welded at the respective ends and welded to each other at the bent portions to form the heat conducting means 8.

FIG. 11 shows a luminance rising characteristic of the sixth embodiment of the multi-tube fluorescent lamp of the present invention, and a comparison multi-tube fluorescent lamp which does not have a heat conducting means but has the same other structure. FIG.

In the figure, the horizontal axis represents time, and the vertical axis represents relative luminance (%). Curve A shows the multi-tube fluorescent lamp of the present embodiment, and curve B shows the multi-tube fluorescent lamp for comparison.

As is clear from the figure, in the case of this embodiment, the luminance during stable lighting is high, but in the case of the comparative multiple tube fluorescent lamp, the luminance is low. This is because, in the case of the comparative multi-tube fluorescent lamp, the temperature of the arc tube becomes excessively high, and the mercury vapor pressure is increased accordingly, and the luminous flux is reduced. On the other hand, in the present embodiment, the temperature rise of the arc tube 1 is moderately suppressed by the heat conducting means 8, so that the mercury vapor pressure is maintained at an appropriate value, and as a result, the decay of the luminous flux is kept small. Have been.

On the other hand, there is almost no difference between the luminance rise from the start of lighting and the luminance rise. In this case, the rise of this embodiment is slightly slower, but this is within a sufficiently allowable range.

FIG. 12 is a sectional view showing a seventh embodiment of the multi-tube fluorescent lamp of the present invention.

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

In the present embodiment, the fixing position of the glass outer tube 2 to the arc tube 1 and the filling in the glass outer tube 2 are different. That is, the end 2a of the outer glass tube 2 is fixed to the arc tube 1 at a position facing between the end 1e of the arc tube 1 and the front surface of the electrode 1b. Mercury and argon are sealed in the outer glass tube 2. The heat conducting means 8 in FIG. 10 is not provided.

Thus, the electrode 1b is kept warm by the glass outer tube 2, but since the end 1e of the arc tube 1 is exposed from the glass outer tube 2, the coldest portion of the arc tube 1 is connected to the end 1e. Can be formed. For this reason, since excess mercury ions are reduced in the plasma in the discharge space, it is possible to suppress the mercury ions from being injected into the glass bulb 1a of the arc tube 1 and depleting the mercury. If the consumption of mercury during the operation is small as described above, it means that the amount of enclosed mercury during manufacturing can be minimized.

Since the discharge space of the arc tube 1 is kept warm by the glass outer tube, the luminance rise is good, but since the fluid heat medium is sealed in the glass outer tube, the heat of the arc tube 1 is reduced. The heat is radiated from the outer glass tube 2 to the outside via the fluid heat medium. For this reason, the temperature rise on the high temperature side of the arc tube 1 is appropriately suppressed. Therefore, there is little decrease in luminance during stable lighting.

FIG. 13 is a sectional view showing an eighth embodiment of the multi-tube fluorescent lamp of the present invention.

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

In the present embodiment, the heat conducting means 8 is provided substantially at the center of the discharge space. That is, the heat conducting means 8 is formed by welding the arc tube 1 and the glass outer tube 2.

FIG. 14 is a partially cutaway sectional view showing a ninth embodiment of the multiple tube fluorescent lamp of the present invention.

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

In the present embodiment, a plurality of heat conducting means 8 are disposed along the discharge path. In other words, a pair of heat conducting means 8 formed by welding is disposed at a distance from an intermediate portion of the discharge space in the longitudinal direction of the arc tube 1. In the drawing, the central portions of the arc tube 1 and the glass outer tube 2 located between the heat conducting means 8 are cut away.

If the multi-tube fluorescent lamp is long to some extent, the temperature distribution of the arc tube can be made uniform by disposing a plurality of heat conducting means 8 along the longitudinal direction of the lamp. It is effective to maintain mechanical strength.

The relationship between the position and the shape of the arc tube and the glass outer tube in a plane orthogonal to the respective axes will be described below with reference to FIGS.

FIG. 15 is a cross-sectional view showing a tenth embodiment of a multi-tube fluorescent lamp according to the present invention.

Although the arc tube 1 and the glass outer tube 2 are both cylindrical, the glass outer tube 2 and the arc tube 1 are eccentrically contacted on one side. This contact constitutes a heat conducting means 8 'for thermally connecting the arc tube 1 and the outer glass tube 2.

In the case where the multi-tube fluorescent lamp of the present embodiment is used as a backlight of a sidelight type or a direct type, when the heat conducting means 8 ′ is opposed to a light guide plate or a diffusion plate, the light guide is increased. The amount of light incident on the light plate can be increased.

On the other hand, when the opposite side of the heat conducting means 8 'is opposed to the light guide plate or the diffusion plate side, the heat retaining effect of the outer glass tube can be kept high. Also, in high-frequency lighting, when the reflector is made of metal, the leakage current of the multi-tube fluorescent lamp due to the reflector can be reduced.

FIG. 16 is a cross-sectional view showing an eleventh embodiment of the multiple tube fluorescent lamp of the present invention.

The arc tube 1 'has an elliptical cylindrical shape, and the outer glass tube 2 has a cylindrical shape.

FIG. 17 is a cross sectional view showing a twelfth embodiment of the multiple tube fluorescent lamp of the present invention.

The arc tube 1 is cylindrical, and the glass outer tube 2 'is elliptical.

FIG. 18 is a cross sectional view showing a thirteenth embodiment of the multiple tube fluorescent lamp of the present invention.

The arc tube 1 'and the glass outer tube 2 are both elliptical cylinders, but the major axes of the ellipses are shifted by 90 °.

FIG. 19 is a sectional view showing a fourteenth embodiment of the multiple tube fluorescent lamp of the present invention.

In the figure, the same parts as those in FIG. 10 are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment is different from FIG. 10 in that the diameter of the heat conducting means 8 is reduced. That is, nickel electrodes 1b were previously sealed to both ends of a glass bulb having an outer diameter of 2.4 mm and a wall thickness of 0.3 mm, and mercury and neon were sealed therein at 80 torr to produce a straight light emitting tube 1. . Thereafter, the arc tube 1 is inserted into the glass outer tube 2 having an outer diameter of 3.2 mm and a wall thickness of 0.3 mm, and one end of the glass outer tube 2 is heated and melted, and connected to one end of the arc tube 1. Next, the outer glass tube 2
After connecting the other end to the exhaust device, the inside of the glass outer tube 2 is heated from the outside to degas while the inside is made high vacuum of 1 Pa. Then, the other end of the glass outer tube 2 is connected to the arc tube 1
And sealed off. Finally, the entire outer periphery of the intermediate portion of the glass outer tube 2 was bent by heating.
The diameter was reduced and welded to the arc tube 1 to form the heat conducting means 8. The arc tube 1 also completed an L-shaped multi-tube fluorescent lamp whose cross section was deformed flat by bending.

The distance between the electrodes was measured to be 60 mm inside the arc tube 1 and 80 mm outside the arc tube 1. The length of the welded portion, that is, the heat conducting means 8 was about 10 mm.

A multi-tube fluorescent lamp (embodiment) manufactured as described above and an L-shaped fluorescent lamp of the same specification except that no glass outer tube is provided for comparison (Comparative Example 1)
A multi-tube fluorescent lamp (Comparative Example 2) having the same specifications as the present embodiment except that the outer tube and the outer tube were provided but the heat conducting means was not provided was manufactured, and the lamp characteristics were measured.

FIG. 20 is a graph showing the relationship between the ambient temperature and the tube surface luminance of the embodiment shown in FIG. 19 and Comparative Example 1.

In the figure, the horizontal axis represents the ambient temperature (° C.), and the vertical axis represents the screen luminance (cd / m ² ). Curve C
Indicates an embodiment, and curve D indicates Comparative Example 1.

In the embodiment, while maintaining the luminance of 20,000 cd / m ² or more over the ambient temperature of −20 ° C. to 40 ° C., and the change was small, Comparative Example 1 exhibited remarkably low luminance at low temperature and low temperature. It was unbearable for use. However, at room temperature or higher, the luminance of the comparative example exceeded.

FIG. 21 is a graph showing the relationship between the lamp current and the lamp current of the embodiment shown in FIG. 19 and Comparative Example 2.

In the figure, the horizontal axis represents the lamp current (mA).
, And the vertical axis indicates the screen luminance (cd / m ² ).
A curve E indicates the embodiment, and a curve F indicates the comparative example 2.

In the embodiment, at a lamp current of about 2.5 mA or more, the tube surface luminance was clearly higher than that of Comparative Example 2, and the luminance difference became more remarkable as the lamp current increased. This indicates that the embodiment is extremely excellent in a practical lamp current range of 3 to 5 mA.

FIG. 22 is a sectional view showing a fifteenth embodiment of the multi-tube fluorescent lamp of the present invention.

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

The present embodiment differs in the shapes of the arc tube 1 and the glass outer tube 2 and the heat conducting means 8 ". That is, the arc tube 1 is L-shaped, and the heat conducting means 8" is made of a heat conductive silicone rubber. Are disposed at the bent portions of the arc tube 1 and the glass outer tube 2.

Thus, the heat of the arc tube 1 is dissipated by the heat conducting means 8 ″.
Is diffused to the outside of the glass outer tube 2 through the above, so that basically the same operation as in the above-described embodiment is performed. Further, since the silicone rubber constituting the heat conducting means 8 "has a suitable elasticity, it performs an excellent shock-absorbing action against an externally applied impact, so that it is further strengthened against vibration.

FIG. 23 is a front view showing a sixteenth embodiment of the multi-tube fluorescent lamp of the present invention.

The same parts as those in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, the multi-tube fluorescent lamp has a U-shape.

Reference numeral 9 denotes a bent portion, which is bent substantially at a right angle in the case of the present embodiment.

FIG. 24 is a front view showing a seventeenth embodiment of the multi-tube fluorescent lamp of the present invention.

The same parts as those in FIG. 23 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the multi-tube fluorescent lamp has a trapezoidal shape.

The bent portion 9 is bent at approximately 45 °.

FIG. 25 is a front view showing an eighteenth embodiment of the multiple tube fluorescent lamp of the present invention.

The same parts as those in FIG. 23 are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, the multi-tube fluorescent lamp has an inverted U-shape.

The bent portion 9 has a semicircular shape.

FIG. 26 is a cross-sectional end view of a curved portion showing a nineteenth embodiment of the multiple tube fluorescent lamp of the present invention.

The arc tube 1 has a glass bulb having an outer diameter of 2.4 m.
m, inner diameter 1.8 mm, discharge medium 97% neon, argon 3% (partial pressure) 10.7 Pa, mercury alloy, electrode cold cathode, phosphor three-wavelength phosphor. .

The outer glass tube 2 had an outer diameter of 3.2 mm and an inner diameter of 2.6 mm, and the inside of the outer glass tube 2 was evacuated to 1.33 Pa or less.

A double-tube fluorescent lamp having a total length of 60 mm having the above-mentioned specifications was bent at a right angle at the center in the longitudinal direction thereof with an inner radius R of 3 mm and provided with a bent portion 9. A double tube fluorescent lamp was obtained.

The present embodiment is characterized in that the arc tube 1 and the glass outer tube 2 surrounding the arc tube 1 are separated over the entire circumference in the bent portion 9. The cross-sectional shapes of the arc tube 1 and the glass outer tube 2 are both elliptical, but this is deformed because the arc tube 1 and the glass outer tube 2 having a circular cross section are curved.

As a result of lighting the obtained double-tube fluorescent lamp, when the lamp current was 5 mA, the lamp voltage was 197 V and the screen luminance was 30,000 cd / m ² (x =
0.284, y = 0m. 306).

FIG. 27 is a graph showing the luminance rise characteristics at different ambient temperatures of the double-tube fluorescent lamp according to the nineteenth embodiment of the present invention shown in FIG.

The lighting conditions are a lamp current of 6.5 mA and a power consumption of 1.2 W.

The measured ambient temperatures are 0 ° C., 25 ° C. and 60 ° C.

In the figure, curve A is 0 ° C. and curve B is 25 ° C.
The curve C shows the luminance rising characteristics at 60 ° C.

FIG. 28 is a graph showing luminance rising characteristics at different ambient temperatures of the double-tube fluorescent lamp in which the specifications of the nineteenth embodiment of the present invention shown in FIG. 26 are slightly changed.

That is, after evacuation of the inside of the glass outer tube to 1.33 Pa or less, 13.3 Pa of xenon was sealed.

The lighting conditions are a lamp current of 2.6 mA and a power consumption of 0.5 W.

The measured ambient temperature is the same as in FIG.

In the figure, curve A is 0 ° C. and curve B is 25 ° C.
The curve C shows the luminance rising characteristics at 60 ° C.

FIG. 29 is a cross-sectional end view of a curved portion showing a twentieth embodiment of the multiple tube fluorescent lamp of the present invention.

The present embodiment is characterized in that the arc tube 1 and the outer glass tube 2 surrounding the arc tube 1 are in contact with each other in a part of the entire circumference in the bent portion 9. Other configurations are shown in FIG.
Same as 6. Other configurations are the same as those of the nineteenth embodiment in FIG.

FIG. 30 is a cross-sectional end view of a curved portion showing a twenty-first embodiment of the multiple tube fluorescent lamp of the present invention.

The present embodiment is characterized in that the arc tube 1 and the glass outer tube 2 surrounding the arc tube 1 are welded in a part of the entire circumference in the bent portion 9. Other configurations are shown in FIG.
6 is the same as the nineteenth embodiment.

FIG. 31 is a graph showing luminance rising characteristics at different ambient temperatures of the double-tube fluorescent lamp of the twenty-first embodiment shown in FIG.

The lighting conditions, measurement conditions and notation are the same as those in FIG.

FIG. 32 is a graph showing luminance rising characteristics at different ambient temperatures of a double tube fluorescent lamp in which the specifications of the twenty-first embodiment shown in FIG. 31 are slightly changed.

That is, after evacuation of the inside of the glass outer tube to 1.33 Pa or less, 13.3 Pa of xenon was sealed.

The lighting conditions, measurement conditions and notations are the same as those in FIG.

FIG. 33 is a cross-sectional end view of a curved portion showing a twenty-second embodiment of the multiple tube fluorescent lamp of the present invention.

This embodiment is characterized in that the arc tube 1 and the glass outer tube 2 surrounding the arc tube 1 are welded over the entire circumference in the bent portion 9. Other configurations are the same as those in FIG.

FIG. 34 is a graph showing the luminance rise characteristics at different ambient temperatures of the double-tube fluorescent lamp according to the twenty-second embodiment of the present invention shown in FIG.

The lighting conditions, measurement conditions and notations are the same as in FIG.

FIG. 35 is a graph showing luminance rising characteristics at different ambient temperatures of the double-tube fluorescent lamp in which the specifications of the twenty-second embodiment of the present invention shown in FIG. 33 are slightly changed.

That is, after evacuation of the inside of the glass outer tube to 1.33 Pa or less, 13.3 Pa of xenon was sealed.

The lighting conditions, measurement conditions and notations are the same as those in FIG.

[0231]

According to the first to twenty-second aspects of the present invention,
The arc tube is surrounded by the glass outer tube, and both ends of the glass outer tube are fixed by glass welding near both ends of the glass bulb of the arc tube. Since the space is directly or indirectly closer to other parts, the luminance rise characteristics are improved, the manufacturing is easy, and the arc tube is hard to be damaged even if an external shock is applied. If the tube and the glass outer tube are in contact with or fixed to each other in a thermally conductive manner, it is possible to provide a multi-tube fluorescent lamp in which the temperature of the arc tube is prevented from rising excessively during stable lighting and the luminance is hardly reduced.

According to the second aspect of the present invention, it is possible to provide a general multi-tube fluorescent lamp for an elongated and compact lighting device.

According to the third aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp which is preferable for an elongated and compact lighting device.

According to the fourth aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp having a simple structure in which the arc tube is brought into contact with the outer glass tube by bending the arc tube.

According to the invention of claim 5, in addition, the multi-tube fluorescent lamp in which the arc tube is eccentrically fixed to the glass outer tube while a part of the peripheral surface of the arc tube is in contact with the inner surface of the glass outer tube. Can be provided.

According to the sixth aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp having a projection on the glass outer tube which comes into contact with the arc tube.

According to the seventh aspect of the invention, it is possible to provide a multi-tube fluorescent lamp in which vibration of the arc tube is suppressed in any direction in a plane perpendicular to the axis of the glass outer tube. .

According to the eighth aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp in which the outer glass tube and the arc tube are brought close to each other by the spacer.

According to the ninth aspect of the present invention, in addition to the provision of the heat conducting means between the arc tube and the outer glass tube at a position facing the discharge space portion of the arc tube, stable lighting of the arc tube can be achieved. It is possible to provide a multi-tube fluorescent lamp in which the subsequent excessive rise in temperature is effectively suppressed and the decrease in luminance is reduced.

According to the tenth aspect of the present invention, in addition to the provision of the heat conducting means including the heat conductive spacer, the arc tube and the glass outer tube can be stably turned on without any particular deformation. A multi-tube fluorescent lamp that suppresses an excessive rise in temperature can be provided.

According to the eleventh aspect of the present invention, since the heat conduction means is constituted by the welded portion of the arc tube and the outer glass tube, it is possible to prevent the temperature of the arc tube from rising excessively, to improve the mechanical strength and to facilitate the manufacture. A multi-tube fluorescent lamp having an effect can be provided.

According to the twelfth aspect of the invention, in addition, since the heat conducting means is constituted by the contact between the arc tube and the outer glass tube, a multi-tube fluorescent lamp which is extremely easy to manufacture can be provided. .

According to the thirteenth aspect of the present invention, the arc tube and the glass outer tube are bent and the heat conducting means is located at the bent portion, so that a bent shape having excellent mechanical strength is formed. A multi-tube fluorescent lamp can be provided.

According to the fourteenth aspect of the present invention, there is provided a multi-tube fluorescent lamp in which a heat-fluid medium is sealed in the space between the outer glass tube and the arc tube to further suppress the temperature rise of the arc tube. Can be provided.

According to the fifteenth aspect of the present invention, in addition, by forming the coolest part in a single part of the arc tube, consumption of mercury is reduced, and fluidity is maintained in the space between the arc tube and the glass outer tube. By enclosing the medium, it is possible to provide a multi-tube fluorescent lamp in which the temperature of the arc tube is prevented from rising excessively.

According to the sixteenth aspect, it is possible to provide a multi-tube fluorescent lamp in which the fluid medium contains an evaporable metal.

According to the seventeenth aspect, it is possible to provide a multi-tube fluorescent lamp in which a fluid medium contains a rare gas.

According to the eighteenth aspect of the present invention, in addition to the fact that the arc tube and the glass outer tube are in contact with each other at their bent portions, the strength against an external impact is improved, and the tubes are brought into contact at the time of bending. So you can
A multi-tube fluorescent lamp that can be easily manufactured can be provided.

According to the nineteenth aspect of the present invention, since the arc tube and the glass outer tube are partially welded at their bent portions, the welded portion becomes the coldest portion. A multi-tube fluorescent lamp suitable for a high case can be provided.

According to the twentieth aspect, since the arc tube and the outer glass tube are welded over their entire circumference at their bent portions, the welded portion becomes an efficient coldest portion. It is possible to provide a multi-tube fluorescent lamp that generates highly efficient luminance in a wide range of ambient temperature.

According to the twenty-first aspect, it is possible to provide a lighting device having the effects of the first to twentieth aspects.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a first embodiment of a multi-tube fluorescent lamp of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is an enlarged sectional view of a main part showing a second embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 4 is a partially cutaway front view showing a third embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 5 is an enlarged front view of a main part of a multi-tube fluorescent lamp according to a fourth embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a main part showing a fifth embodiment of the multiple tube fluorescent lamp of the present invention.

FIG. 7 is a cross-sectional view of a liquid crystal backlight showing a lighting device according to a first embodiment of the present invention.

FIG. 8 is a conceptual sectional view of a reading device showing a second embodiment of the illumination device of the present invention.

FIG. 9 is a cross-sectional view of a conventional double-tube fluorescent lamp.

FIG. 10 is a front view showing a sixth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 11 is a graph showing the luminous flux rising characteristics of a sixth embodiment of the multi-tube fluorescent lamp of the present invention and a comparative multi-tube fluorescent lamp having no heat conducting means but having the same other structure.

FIG. 12 is a sectional view showing a multi-tube fluorescent lamp according to a seventh embodiment of the present invention.

FIG. 13 is a sectional view showing an eighth embodiment of a multi-tube fluorescent lamp according to the present invention;

FIG. 14 is a partially cutaway sectional view showing a ninth embodiment of the multiple tube fluorescent lamp of the present invention.

FIG. 15 is a cross-sectional view showing a tenth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 16 is a cross-sectional view showing an eleventh embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 17 is a cross-sectional view showing a twelfth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 18 is a cross-sectional view showing a thirteenth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 19 is a sectional view showing a fourteenth embodiment of a multi-tube fluorescent lamp of the present invention.

20 is a graph showing the relationship between the ambient temperature and the display surface brightness of the embodiment shown in FIG. 19 and Comparative Example 1.

21 is a graph showing the relationship between the lamp current and the lamp current of the embodiment shown in FIG. 19 and Comparative Example 2;

FIG. 22 is a cross-sectional view showing a fifteenth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 23 is a front view showing a sixteenth embodiment of the multiple tube fluorescent lamp of the present invention;

FIG. 24 is a front view showing a seventeenth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 25 is a front view showing an eighteenth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 26 is an end view of a cross section of a curved portion showing a nineteenth embodiment of a multiple tube fluorescent lamp of the present invention.

FIG. 27 shows a second embodiment of the nineteenth embodiment of the present invention shown in FIG.
Graph showing luminance rise characteristics of double-tube fluorescent lamps at different ambient temperatures

FIG. 28 is a graph showing luminance rise characteristics at different ambient temperatures of a double-tube fluorescent lamp in which the specifications of the nineteenth embodiment of the present invention shown in FIG. 26 are slightly changed.

FIG. 29 is an end view of a cross section of a curved portion showing a twentieth embodiment of a multiple tube fluorescent lamp of the present invention.

FIG. 30 is an end view of a cross section of a curved portion showing a twenty-first embodiment of the multiple tube fluorescent lamp of the present invention.

FIG. 31 shows a second embodiment of the twenty-first embodiment of the present invention shown in FIG.
Graph showing luminance rise characteristics of double-tube fluorescent lamps at different ambient temperatures

FIG. 32 is a graph showing luminance rise characteristics at different ambient temperatures of a double-tube fluorescent lamp in which the specifications of the twenty-first embodiment of the present invention shown in FIG. 31 are slightly changed.

FIG. 33 is an end view of a cross section of a curved portion showing a twenty-second embodiment of the multiple tube fluorescent lamp of the present invention.

FIG. 34 shows a second embodiment of the twenty-second embodiment of the present invention shown in FIG.
Graph showing luminance rise characteristics of double-tube fluorescent lamps at different ambient temperatures

FIG. 35 is a graph showing luminance rise characteristics at different ambient temperatures of a double-tube fluorescent lamp in which the specifications of the twenty-second embodiment of the present invention shown in FIG. 33 are slightly changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Arc tube 1a ... Glass bulb 1b ... Electrode 1c ... Lead wire 2 ... Glass outer tube

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yui Ishizaki 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Litec Corporation (72) Inventor Naoki Tsutsui 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo No. 1 Toshiba Litec Co., Ltd. (72) Inventor Masami Takagi 3-1-1 Higashishinagawa, Shinagawa-ku, Tokyo (72) Inventor Eiji Suegi 4-chome Higashishinagawa, Shinagawa-ku, Tokyo No.3-1 Toshiba Litec Corporation

Claims (21)

[Claims] An elongated airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge medium sealed in the glass bulb. An arc tube, which surrounds the arc tube with a gap formed around it and whose both ends are fixed by glass welding near both ends of a glass bulb of the arc tube and which faces the discharge space of the arc tube; And a glass outer tube which is directly or indirectly closer to other parts than the other. 2. The arc tube has an outer diameter of 6 mm or less and a thickness of 1 mm.
The outer diameter of the glass outer tube is 8 mm or less and the wall thickness is 1
2. The multi-tube fluorescent lamp according to claim 1, wherein the diameter is equal to or less than mm. 3. The arc tube has an outer diameter of 4 mm or less and a wall thickness of 0.1 mm.
1-0.7 mm, total length 30-400 mm; glass outer tube, outer diameter 6 mm or less, wall thickness 0.1-0.7 m
3. The multi-tube fluorescent lamp according to claim 1, wherein m has a total length of 30 to 400 mm. 4. 4. The multi-tube fluorescent lamp according to claim 1, wherein the arc tube has a curved middle portion and is in contact with the inner surface of the glass outer tube. 5. The glass tube according to claim 1, wherein the arc tube is eccentrically fixed to the glass outer tube while a part of the peripheral surface is in contact with the inner surface of the glass outer tube. Multi-tube fluorescent lamp. 6. The multi-tube fluorescent lamp according to claim 1, wherein the glass outer tube has a projection on an inner surface at an intermediate portion thereof, the projection being in contact with the arc tube. 7. The multi-tube fluorescent lamp according to claim 1, wherein the outer glass tube has projections approaching the three arc tubes at intervals of about 120 °. 8. The multi-tube fluorescent lamp according to claim 1, wherein the outer glass tube and the arc tube are close to each other by interposing a spacer therebetween. 9. An airtight glass bulb, comprising a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge medium sealed in the glass bulb. An arc tube; an outer glass tube surrounding the arc tube with a gap formed therearound and having both ends fixed near both ends of a glass bulb of the arc tube; and emitting light at a position facing the discharge space of the arc tube. And a heat conducting means for connecting the tube and the outer glass tube in a heat conducting relationship. 10. A multi-tube fluorescent lamp according to claim 9, wherein said heat conducting means is a heat conducting spacer. 11. The multi-tube fluorescent lamp according to claim 9, wherein the heat conducting means is a welded portion formed by welding the arc tube and the glass outer tube to each other. 12. The multi-tube fluorescent lamp according to claim 9, wherein the heat conducting means is a contact portion formed by directly contacting the arc tube and the outer glass tube in a thermally conductive manner. 13. The arc tube comprises a plurality of straight portions and at least one bend interposed between the straight portions;
The outer glass tube is bent to the shape of the arc tube;
The multi-tube fluorescent lamp according to any one of claims 9 to 12, wherein the heat conducting means is located at a bent portion of the arc tube and the outer glass tube. 14. A fluid heating medium is sealed in a space between the arc tube and the glass outer tube.
14. The multi-tube fluorescent lamp according to any one of claims 13 to 13. 15. An elongate airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge medium sealed in the glass bulb. A light-emitting tube; a glass outer tube surrounding the light-emitting tube with a gap formed therearound and having both ends fixed by glass welding between portions facing the end of the light-emitting tube and the front surface of the electrode; And a sealed fluid heat medium. 16. The multi-tube fluorescent lamp according to claim 14, wherein at least a part of the fluid heat medium is an evaporable metal. 17. The multi-tube fluorescent lamp according to claim 14, wherein at least a part of the fluid heat medium is a rare gas. 18. An elongated airtight glass bulb having a bent portion, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge sealed in the glass bulb. An arc tube comprising a medium;
It has a curved portion along the arc tube and is in contact with the arc tube at the curved portion, but forms a gap around the other portion to surround the arc tube and to have both ends of the glass bulb of the arc tube at both ends. A glass outer tube fixed near both ends; heat conduction means connecting the arc tube and the glass outer tube in a heat conductive relationship at a position facing the discharge space of the arc tube;
A multi-tube fluorescent lamp comprising: 19. An elongated airtight glass bulb having a bent portion, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge sealed in the glass bulb. An arc tube comprising a medium;
It has a curved portion along the arc tube, and a part of both curved portions is welded at the curved portion, but a gap is formed around the other portion to surround the arc tube and both ends are formed by the arc tube. A glass outer tube fixed in the vicinity of both ends of the glass bulb; and heat conducting means for connecting the arc tube and the glass outer tube in a heat conducting relationship at a position facing the discharge space of the arc tube. A multi-tube fluorescent lamp characterized in that: 20. An elongated airtight glass bulb having a bent portion, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on the inner surface side of the glass bulb, and a discharge sealed in the glass bulb. An arc tube comprising a medium;
It has a curved portion along the arc tube, and both curved portions are welded all around the curved portion, but in other portions, a gap is formed around the arc tube to surround the arc tube and both ends emit light. A glass outer tube fixed near both ends of the glass bulb of the tube; and heat conducting means for connecting the arc tube and the glass outer tube in a heat conducting relationship at a position facing the discharge space of the arc tube. A multi-tube fluorescent lamp characterized in that: 21. A lighting device comprising: a lighting device main body; and a multi-tube fluorescent lamp according to any one of claims 1 to 20 disposed in the lighting device main body.