JP2003346724A - Fluorescent lamp, and lighting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent lamp capable of exhibiting original circumferential temperature characteristics in a state of being mounted to a lighting device. <P>SOLUTION: Electrodes at both ends of a bulb 1 have a long inner lead wire 6, and a filament 4 is kept away from the coldest part at the end part of the bulb. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp for improving the light emission characteristics of a fluorescent lamp and a lighting device using the fluorescent lamp.

[0002]

2. Description of the Related Art In general, it is known that the brightness of a fluorescent lamp changes depending on the vapor pressure of mercury inside the mercury and the mercury collects in the coolest part, so that the brightness changes depending on the temperature of the coolest part. The coolest part is a part where the temperature becomes the lowest inside the bulb when the fluorescent lamp is turned on while the ambient temperature of the fluorescent lamp is constant. When the temperature of the coldest part peaks at 50 ° C. and exceeds 50 ° C., the brightness decreases.

On the other hand, various studies have been made to date. For example, many patent publications disclose a technique for controlling the mercury vapor pressure by changing the composition of mercury amalgam and a technique for installing mercury amalgam in the coolest part. Japanese Patent Application Laid-Open No. 6-267501 discloses a fluorescent lamp which is designed so that one predetermined end of a bulb of a lamp is a coldest part and the temperature of the coldest part is lower. I have.

In recent years, a tube diameter φ15.5 mm called T5
(Hereinafter referred to as HE type) has been commercialized. This is intended for a high-efficiency system dedicated to high-frequency lighting, and is lit by a dedicated lighting device. In order to achieve higher output, there is a type (hereinafter, referred to as an HO type) in which the lamp current is increased with the same T5 straight tube fluorescent lamp. In this type, since the lamp power is very large with respect to the size of the lamp, the temperature of the lamp itself becomes higher than that of the HE type. Therefore, there has been a problem that the temperature of the coldest part becomes higher than 50 ° C. and the luminous efficiency is reduced.

In order to solve this problem, as shown in FIG. 2, one inner lead wire extends inward from the end of the bulb tube, and the filament as a heat source is moved away from the end of the sealed bulb tube, so that the coldest part is formed. A fluorescent lamp that suppresses the temperature rise of the lamp has been considered. If the lighting device for lighting the HE-type and HO-type straight tube fluorescent lamps is also miniaturized together with the lamp, the heat generated from the lighting circuit in the lighting device required for lighting the lamp is reduced by the size of the appliance. Since the heat dissipation deteriorates and the temperature rise becomes rather large, the coldest part around this lighting circuit reduces the temperature of the coldest part as much as possible even if the coldest part is kept away from the filament. However, the temperature rises.

[0006]

As described above, even when using an improved fluorescent lamp in which the inner lead wire is extended inward only on one side of the electrode and the filament is kept away from the coldest part, it is mounted on an actual lighting device. Then, if the lighting circuit in the lighting device is arranged around the coldest part,
Due to heat radiation from the lighting circuit, there has been a problem that the improved light emission characteristics of the fluorescent lamp cannot be exhibited.

[0007] When the straight tube fluorescent lamp is lit horizontally, the coldest part is usually formed at the end of the bulb tube, which is the back of the filament. When the filament is moved away from the bulb tube end on only one side as described above, the coldest part is formed at the bulb tube end on the lower side of the electrode, and in order to lower the temperature of the coldest part, a lighting circuit that generates heat in the lighting device. The mounting direction of the valve must be determined in a certain direction, taking into account that the position and the coldest part do not approach each other.

[0008]

A fluorescent lamp according to the present invention comprises:
In order to solve the above problems, the inner lead wire of the electrode in the bulb is extended not only on one side but also on both ends, and the filament is positioned at a position 30 to 60 mm from the bulb tube end. By doing so, keep the coldest part at the end of the valve tube away from the filament,
A fluorescent lamp having two coolest portions is characterized.

When the fluorescent lamp of the present invention is mounted on a lighting device, the farthest side from the lighting circuit is the coldest portion, regardless of the location of the lighting circuit that generates heat in the lighting device. Is not heated, so that high efficiency can be maintained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventors of the present invention have investigated and found that the characteristics of the brightness and the ambient temperature obtained when the fluorescent lamp is lit alone without being affected by the ambient temperature are the characteristics when the lighting device is mounted. Was different. It has been clarified that this phenomenon largely depends on the shape of the lighting device and the position of the lighting circuit that generates heat in the lighting device.

As a result, the inventors considered changing the position of the coldest part in the bulb depending on the arrangement of the lighting device. That is,
It is considered that the coolest part is not one fixed position but two coolest parts whose positions change according to the temperature rise by the lighting device.

When the ambient temperature increases, the temperature of the coldest part in the valve also increases. In order to lower the temperature of the coldest part, there is a lighting circuit that generates heat even if one electrode has a long inner lead wire and the filament is kept away from the coldest part that can be the end of the bulb tube, etc. Then, the coldest part is heated by the heat radiation from the lighting circuit, and the effect of improving the luminous efficiency is significantly reduced.

Therefore, if the coldest part is farther from the lighting circuit, the influence is reduced, and the light emission characteristics of the lamp alone are approached. Here, the lighting circuit indicates an electronic ballast or a magnetic ballast.

FIG. 1 is a view showing an embodiment of a fluorescent lamp 1 and a lighting device 2 according to the present invention. In this case, in FIG. 1A, the coolest part is B, and is not A around the lighting circuit 3 in the lighting device 2. FIG. 1B is a diagram showing that the lighting circuit 3 in the lighting device 2 has been changed to a position different from that in FIG. In this case, contrary to FIG. 1A, the coldest portion is A, and not B around the lighting circuit 3.

FIG. 2 is a diagram showing a bulb end of a fluorescent lamp. FIG. 2A shows a normal electrode.
(B) is an illustration of an electrode with a long inner lead and with the filament moved away from the bulb tube end according to the present invention. In this case, the long inner lead wire is 36.5 m
m, which is higher than a normal electrode.

FIG. 3 shows the fluorescent lamp of the normal electrode shown in FIG. 2 (a) and the fluorescent lamp of the electrode shown in FIG. 2 (b) in which both ends have long inner lead wires and the filament is kept away from the end of the bulb tube. It is a figure which shows the ambient temperature characteristic in a single body. The horizontal axis indicates the ambient temperature of the fluorescent lamp, and the vertical axis indicates the relative luminous flux when the brightness at 25 ° C. of each fluorescent lamp is 100%.

In the comparative example, since the filament is close to 20.0 mm from the end of the bulb tube, and the coldest part is heated by the heat generated by the filament, the maximum luminous flux is 20 to ambient temperature.
It is around 25 ° C. In the fluorescent lamp of the present invention having long inner lead wires at both ends, the brightness characteristic with respect to the ambient temperature shifts to a higher temperature side by about 15 ° C. than the fluorescent lamp of a normal electrode, and when the ambient temperature is around 35 to 40 ° C. The luminous flux reaches a peak, and the luminous flux is increased by about 10% from that at 25 ° C.
That is, the temperature of the coldest part of the fluorescent lamp having the long inner lead wires at both ends is reduced by about 15 ° C. due to the fact that the filament is farther from the coldest part.

Therefore, the temperature of the coldest part when mounted on the lighting device is around 50 ° C., and a decrease in brightness due to a rise in temperature of the coldest portion is suppressed. The luminous flux can be increased as compared with turning on the lamp alone.

[0019]

As described above, according to the present invention, the temperature of the coldest part of the fluorescent lamp can be kept lower than usual by providing the electrodes at both ends with long inner lead wires. Even if the lighting device is mounted on a lighting device having a built-in lighting circuit at a position, it is possible to obtain a fluorescent lamp which suppresses a decrease in brightness and increases the brightness, and a fluorescent lamp lighting device using the fluorescent lamp as a light source.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a fluorescent lamp and a lighting device of the present invention.

FIG. 2 is a sectional view showing a normal electrode and an electrode portion having a long inner lead wire.

FIG. 3 is a graph showing temperature characteristics of a fluorescent lamp according to an example of the present invention and a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Valve, 2 ... Lighting device, 3 ... Lighting circuit, 4 ... Filament, 5 ... Inner lead wire, 6 ... Long inner lead wire, 7 ... Base, A, B ... Coolest part.

Claims (4)

[Claims] 1. A fluorescent lamp in which electrodes are provided at both ends of a bulb in which mercury or a mercury compound and a rare gas are sealed, and wherein a filament located at both ends of the bulb is sealed. 30-60mm from the pipe end
A fluorescent lamp, which is located inside. 2. The fluorescent lamp according to claim 1, wherein the bulb diameter is 15 to 32 mm. 3. The fluorescent lamp according to claim 1, wherein the lighting frequency is 40 kHz or more. 4. A fluorescent lamp lighting device using the fluorescent lamp according to claim 1 as a light source.