JPH08298101A - Bent discharge lamp and lighting device - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a discharge lamp in which the strength of a bent portion bent into an acute angle of approximately right angle or less is improved and a bulb is not damaged, and an illumination device equipped with this lamp. [Structure] A bent discharge lamp L, L1 and a discharge lamp L, L1 in which a bent glass tube bulb 1 is provided with a discharge electrode and a protective coating 6 is applied to a bent portion 2 of the bulb 1 are used. The lighting device B. [Effect] Since the bent portion formed on the glass tube bulb is covered with the transparent coating, the strength of the bent portion can be improved without deteriorating the light emission characteristics. Therefore, the bent portion is less likely to be damaged by the vibration or impact applied to the lamp, and the maintainability of the lighting device such as the backlight device using the lamp can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending discharge lamp used for general lighting, OA equipment such as personal computers and word processors, and display devices such as televisions and meters, and a backlight device equipped with this discharge lamp. Related to a lighting device.

[0002]

2. Description of the Related Art In recent years, small personal computers, televisions, etc., or display devices for displaying characters and figures, which use a liquid crystal display device (hereinafter abbreviated as LCD), have been miniaturized and have high brightness. For example, a fluorescent lamp used in a backlight device for illuminating an LCD or a display device has a small input, and has a smaller diameter and a smaller size, lower power consumption, and higher power consumption than a fluorescent lamp for general lighting. Luminance,
High color rendering properties and long life are desired.

In a backlight system such as a direct type in which a straight tube type fluorescent lamp is disposed on the lower surface side of a light diffusing plate, uneven illuminance occurs, so that the discharge lamp has a plurality of straight tube types. Since the lamp is used, a lighting circuit device is required for each, and there is a problem that the cost is high and the number of parts is large. Therefore, instead of this straight-tube type lamp, a U-shaped or W-shaped bent lamp with a large light emitting area has come to be used, and a uniform illuminance distribution can be obtained, while reducing costs and reducing the number of parts. It is becoming increasingly popular.

Further, in the case of an edge light system in which light is made to enter the light guide plate from an edge portion, a straight tube type fluorescent lamp is arranged along one side surface of the light guide plate or the other side surface opposite to this side surface. A substantially uniform luminance surface is formed on the upper surface of the light guide plate by using a reflector or a diffuser provided on the bottom surface of the light incident from each edge portion. In the edge-light system that uses a straight-tube fluorescent lamp as described above, because the lamps are arranged in the same direction, the brightness uniformity on the substrate surface is improved. Is required. Further, since the use of a plurality of lamps increases the cost and the number of parts in the same manner as described above, instead of the straight tube type lamp, the fluorescent lamp in which the bulb is bent into an L shape is used as a means for further increasing the uniformity. A lamp has been developed, and it is known that the lamp is arranged so as to face a side surface adjacent to a light guide plate.

However, in the fluorescent lamp in which the above bulb is bent in an acute angle such as U-shape, W-shape or L-shape, there is some problem in the bending part in terms of strength. This is because the glass tube originally in the form of a straight tube was forcibly bent to form the bulb, and the part that was melted and softened by heating during the bending process was compressed inside the bent part to form a flesh deposit. The outside is pulled so it is thin. in this way,
The bent portion is often strained by heating during bending and stressed by a thin glass portion or glass thickness deviation, and is weaker in strength than a straight portion that is not processed. In particular, an L-shaped lamp or the like is weak in shape and is easily damaged even if it is supported, and thus requires careful handling.

Therefore, there is a problem that when the lamp is mounted on the backlight device or the like or is transported, if the bending portion is subjected to a force, the bending portion may be damaged, and the handling work should be carefully performed. There was a problem that it was necessary and time-consuming.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a discharge lamp in which the strength of a bent portion bent into an acute angle of approximately right angle or less is improved and a bulb is not damaged, and this lamp is mounted. It is an object of the present invention to provide an illuminating device.

[0008]

According to another aspect of the present invention, there is provided a bent discharge lamp, wherein a bent glass tube bulb is provided with a discharge electrode, and the bent portion of the bulb is provided with a protective coating. It is characterized by that.

In the bent discharge lamp according to claim 2 of the present invention, the bent portion of the glass tube bulb is L-shaped or U-shaped.
It is characterized by a letter shape or a shape similar to these.

The bent discharge lamp according to claim 3 of the present invention is characterized in that the bent portion of the glass tube bulb has an acute angle of not more than a right angle.

The bent discharge lamp according to claim 4 of the present invention is characterized in that the shape of the glass tube bulb is one of L-shaped, U-shaped, W-shaped and WU-shaped.

In the bendable discharge lamp according to claim 5 of the present invention, the protective coating is made of a heat-shrinkable material selected from at least one of fluororesin, nylon, silicone, vinyl chloride and olefin resin. Is characterized by.

The bendable discharge lamp according to claim 6 of the present invention is characterized in that the protective coating is transparent.

An illumination device according to a seventh aspect of the present invention is a main body, the bent discharge lamp according to any one of the first to sixth aspects, which is disposed in the main body, and the lamp. And a lighting circuit device.

According to an eighth aspect of the present invention, there is provided an illuminating device according to the first aspect, wherein the main body of the fixture, a light guide plate or a light diffusing plate provided on the main body, and the light guide plate or the light diffusing plate are provided. The bent discharge lamp according to any one of claims 6 to 6 and a lighting circuit device for the lamp are provided.

[0016]

[Function] By providing a protective coating on the bent portion of the bulb, even if a slight stress or shock is applied to the bent portion, the coating such as a film cushions and softens the bent portion to reinforce the bent portion and prevent damage to the glass. It can be prevented and the strength can be improved.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a W-shaped fluorescent lamp, and FIG. 2 is a side sectional view of a backlight device of an LCD equipped with the W-shaped fluorescent lamp.

In this fluorescent lamp L, the bulb 1 has three bent portions 2, 2 and 2 formed by folding a straight tubular glass tube made of soft glass such as soda lime glass or lead glass three times in the middle portion. It has a W-shape (also referred to as an M-shape) having four straight pipe portions 3, 3, 3 and 3, and the discharge path is composed of one continuous passage. Then, for example, the stems 5 and 5 are respectively sealed to the sealing portions 4 and 4 at the ends of the straight pipe portions 3 and 3 on both outer sides.

A filament electrode 52 wound with a tungsten wire is connected to the tip ends of the lead wires 51, 51 extending into the bulb 1 of each stem 5.

The inner surface of the bulb 1 is mixed with phosphors having, for example, blue, green and red light emitting regions.
A wavelength type phosphor film (not shown) is formed, and the bulb 1 is filled with an inert gas such as Ar (argon).

Reference numerals 6, 6 and 6 denote bent portions 2 of the valve 1.
A heat-shrinkable protective coating made of, for example, a fluororesin polytetrafluoroethylene (trade name: Teflon) having a thickness of about 0.1 to 0.3 μm is formed so as to cover the second and second portions.

In the W-shaped fluorescent lamp L thus constructed, the bent portions 2, 2, 2 of the bulb 1 are reinforced by the coating 6, and the coating 6 has higher elasticity than glass. It does not easily break even if a little stress or shock is applied during handling such as packaging, transportation and lighting. Further, the protective cover 6 was colorless and transparent, and there was no loss of light transmission in the part of the cover 6 and no deterioration of the light emission characteristics was observed.

Further, the W-shaped fluorescent lamp L is an LCD backlight device (illumination device) as shown in FIG.
Used for B. In FIG. 2, reference numeral 71 denotes a light diffusion plate, and the fluorescent lamp L mounted on the main body 8 also serving as a reflector is disposed on the lower surface of the light diffusion plate 71. Reference numeral 9 is a lighting circuit device having a high frequency lighting circuit for lighting the lamp L.

Such a backlight device (illumination device)
Also in B, the fluorescent lamp L in which the bent portions 2, 2, 2 are reinforced is mounted on the main body (reflector) 8 or when the backlight device (illumination device) B is packaged, transported, or used for OA equipment. It was not easily broken even if a little stress or impact was applied after mounting, and the light emitting characteristics were not deteriorated.

FIG. 3 shows another embodiment of the fluorescent lamp of the present invention. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. The lamp shown in FIG. 3 is an L-shaped fluorescent lamp L1 in which a straight tube-shaped glass tube bulb 1 is provided with a bent portion 2 at a substantially right angle in a substantially central portion thereof. Then, lead wires 51 supporting a cold cathode type discharge electrode 55 formed of a nickel (Ni) plate or the like are sealed to the sealing portions 4 and 4 at both ends of the bulb 1, respectively. A protective coating 6 of a colorless and transparent resin is formed on the bent portion 2 of the valve 1 as in the above embodiment.

Further, a phosphor film having a predetermined light emitting region is formed on the inner surface of the bulb 1, and the bulb 1 is filled with an inert gas such as Ar (argon).

Reference numeral 72 is a transparent plate-shaped light guide plate made of a synthetic resin material such as acrylic. An L-shaped fluorescent lamp L1 is additionally provided so as to face the edge portions of the two side surfaces of the light guide plate 72 that are connected to each other. Further, unevenness for light diffusion, a reflection film for light reflection, etc. are formed on one surface of the light guide plate 72, and a display plate and a liquid crystal plate (not shown) are arranged on the open surface of the light guide plate 72. ing.

When the L-shaped fluorescent lamp L1 is turned on, the light emitted from the lamp L1 enters from the edge portion of the side surface of the light guide plate 72, is reflected on the lower surface side, and is emitted from the open surface on the upper surface side. The front display plate and the liquid crystal plate are illuminated to display a predetermined display.

In this L-shaped fluorescent lamp L1 as well, since the resin coating 6 is formed on the bent portion 2 of the bulb 1 to reinforce it, even when the lamp L1 alone is incorporated into the backlight device. However, it was not easily damaged when a little stress or impact was applied, and no deterioration in light emission characteristics was observed.

Incidentally, in the LCD backlight device of FIG. 3, the light guide plate 72 has a side length of about 155 mm and a thickness of about 5 mm, and the fluorescent lamp L1 has a cold cathode discharge electrode 5.
Power consumption of about 3.5 W, the glass tube bulb 1 made of soda-lime glass has an outer diameter of about 3 mm and an inner diameter of about 2 m.
m, the length of the straight tubular portion on one side is about 160 mm, the radius of the outer surface side of the bent portion 2 is 7 to 10 mm, and the radius of the inner surface side of the bent portion 2 is 4 to 6 mm.

In such a structure, the fluorescent lamp L1
Is connected to a predetermined high frequency lighting circuit and the lamp current is 5 mA,
It was lit at a lamp voltage of 500 V and a frequency of 30 KHz. Then, the luminance (nt ... Knit) at the bent portion 2 of the fluorescent lamp L1 and the fluorescent lamp of the conventional structure which is not covered for comparison is measured, and as shown in comparison with Table 1, there is a significant difference between the two. No difference was found.

[0032]

[Table 1]

FIG. 4 shows the state of a strength comparison test with and without the protective coating 6 on the bent portion 2 of the L-shaped fluorescent lamp L1. In the test, from the outside of the valve 1 extending upward from the bent portion 2, the distance was changed and a force was applied in the bending direction to examine the breaking strength. In FIG. 4, the horizontal axis is the distance C (mm) from the bent portion 2 to the portion to which the force is applied, and the vertical axis is the value of the force F applied to the valve 1 bent in the L shape (unit: kgf ...
1kgf = 9.8N).

As is apparent from FIG. 4, the product of the present invention in which the bent portion 2 is provided with the protective coating 6 is 1.4 to 2 times stronger than the conventional product in which the coating 6 is not provided. Damage to the bent portion 2 can be reduced.

Next, the operation of coating the bent portion 2 of the bulb 1 of the fluorescent lamp L or L1 with resin will be described. The W-shaped fluorescent lamp L or the L-shaped fluorescent lamp L1 is manufactured through a normal process. First, a heat-shrinkable tube made of, for example, a fluororesin having a diameter slightly larger than the outer diameter of the bulb 1 and longer than the length of the bent portion 2 is prepared. Then, the bent portion 2 is brought from the sealing portion 4 at the end portion of the bulb 1 through the heat-shrinkable tube made of fluororesin prepared. Next, the heat-shrinkable tube is heated and contracted by hot air or the like to be tightly fixed to the outer wall of the valve 1 of the bent portion 2. When there are a plurality of bent portions 2, they may be sequentially performed, or the heat-shrinkable tube may be heated and shrunk after all the predetermined bent portions 2 are aligned.

The present invention is not limited to the above embodiment. For example, the bent discharge lamp has been described as a mercury-filled fluorescent lamp, but the present invention can also be applied to a low-pressure discharge lamp having another thin tube-shaped bent portion such as a discharge lamp that emits noble gas without containing mercury. Further, the bent portion formed in the glass tube bulb is covered with a U-shaped, V-shaped or L-shaped bent portion having an acute angle equal to or less than a right angle including a substantially right angle to obtain preferable results. The shape of the U-shaped, V-shaped, L-shaped, W (M) -shaped, W
It can be applied to U-shaped lamps.

Further, as the material of the coating applied to the bent portion,
Not only fluorine resin (trade name: Teflon), but also nylon, silicone (silicone rubber or silicone resin), vinyl chloride, polyolefin (polyethylene, polypropylene, etc.) have good transparency and elasticity. There was the effect of. The method of coating these materials is not limited to heat shrinkage, and other means may be used.

Further, the discharge electrode of the lamp is not limited to one provided in the bulb, but may have three or more electrodes such as an intermediate electrode, and the discharge electrode is not limited to the internal electrode and is provided on the outer surface of the bulb. It may be an external electrode.

Further, the material of the glass tube, the kind of the discharge electrode, etc. are not limited to those of the embodiment.

Furthermore, the lighting device to which the bent discharge lamp is attached and used is not limited to the backlight device for liquid crystal display and the display device, and may be applied to the lighting device used for general lighting. However, the discharge lamp may be arranged such that it is directly or indirectly held by the main body of the lighting device.

[0041]

As described above in detail, according to the present invention, since the bent portion formed on the glass tube bulb is covered with the transparent protective coating, the strength of the bent portion is improved without deteriorating the light emission characteristics. did it. Therefore, the bent portion is less likely to be damaged by the vibration or impact applied to the lamp, and the maintainability of the lighting device such as the backlight device using the lamp can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a W-shaped fluorescent lamp of the present invention.

FIG. 2 is a partially cutaway plan view showing an embodiment of a backlight device (illumination device) of the present invention.

FIG. 3 is a top view showing an embodiment of the display device (illumination device) of the present invention.

FIG. 4 is a graph showing the strength of the bent portion of the L-shaped lamp of the present invention configuration and the conventional configuration in comparison.

[Explanation of symbols]

 L, L1: Fluorescent lamp (flexible discharge lamp) 1: Glass tube bulb 2: Bent part 6: Protective coating B: Backlight device (illumination device) 71: Light diffusion plate 72: Light guide plate 8: Main body 9: Lighting circuit apparatus

Claims (8)

[Claims] 1. A discharge lamp in which a bent glass tube bulb is provided with a discharge electrode, wherein the bent portion of the bulb is provided with a protective coating. 2. The bent discharge lamp according to claim 1, wherein the bent portion of the glass tube bulb has an L-shape, a U-shape, or a shape similar thereto. 3. The bent discharge lamp according to claim 1, wherein the bent portion of the glass tube bulb has an acute angle equal to or less than a right angle. 4. The bent discharge lamp according to claim 1, wherein the shape of the glass tube bulb is one of an L shape, a U shape, a W shape and a WU shape. 5. The bent discharge according to claim 1, wherein the protective coating is made of a heat-shrinkable material selected from at least one of fluororesin, nylon, silicone, vinyl chloride, and olefin resin. lamp. 6. The bendable discharge lamp according to claim 5, wherein the protective coating is transparent. 7. A main body, a bent discharge lamp according to any one of claims 1 to 6 arranged on the main body, and a lighting circuit device for the lamp. Characteristic lighting device. 8. The main body, a light guide plate or a light diffusion plate provided on the main body, and the bend according to claim 1, which is attached to the light guide plate or the light diffusion plate. A lighting device comprising a shape discharge lamp and a lighting circuit device for the lamp.