JPH07320683A - Fluorescent lamp and lighting system using same - Google Patents

Abstract

PURPOSE:To provide a fluorescent lamp where a flicker is prevented during lighting by stabilizing an anode generating spot to be generated in a filament coil. CONSTITUTION:In a fluorescent lamp where a filament coil 4 interposed between a pair of inside lead wires 3 is disposed at the end of a bulb, and is provided at both ends of a coil portion 5 with legs 6 connected to the inside lead wires, CRXP>=0.55, wherein CR represents a cold resistance value of the leg of the filament coil 4; and P, a pitch of the coil portion. Consequently, if the cold resistance value CR of the leg is increased, a change in temperature is decreased. Meanwhile. if a pitch of the coil portion is increased, glow generated inside the coil portion is likely to be diffused so that an anode spot is stably generated in the leg, thus preventing a flicker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp which prevents a flicker phenomenon during lighting and a lighting device using the same.

[0002]

2. Description of the Related Art Generally, in a fluorescent lamp, a fluorescent coating is formed on the inner surface of a glass bulb, and filament coils are sealed at both ends of the bulb, and a predetermined amount of mercury, argon, etc. is placed in the bulb. It is configured by enclosing the rare gas of. The filament coil is formed by molding a tungsten wire into a double coil or a triple coil, and the leg portions formed at both ends of the coil portion are clamped to the internal lead wires, respectively. It is installed between.

By the way, when such a fluorescent lamp is lit by alternating current, the brightness fluctuates at the end of the bulb, which may cause so-called irregular flicker. Such flicker is caused by irregular vibration of the anode, which gives an unpleasant feeling.

It is considered that such irregular anode vibration is caused by the following phenomenon. That is, when the filament coil on the one end side of the bulb is in the anode mode, electrons fly into this filament coil. In general, electrons have the property of jumping to a place where the distance between electrodes is short or a place where the potential level is high. However, when the potential difference between the coil portion of the filament coil and the leg portions formed at both ends of this coil portion is small, the position where the electrons jump in (anode point) is the coil portion or is formed at both ends of the coil portion. It may be a leg part or a tip part (clamp part) of the internal lead wire. When the anode point moves in this manner, the oscillation of the anode becomes unstable, which causes the lamp voltage during lighting to fluctuate and the lamp current to change. As a result, there is a problem that flicker occurs even during stable lighting.

In order to prevent this, conventionally, as shown in FIG. 6, there has been proposed a fluorescent lamp having a structure in which auxiliary electrodes 20, 20 extending to the discharge space side are joined to the internal lead wires 3, 3, respectively. In FIG. 6, 1 is a bulb, 2 is a stem, 4 is a filament coil, and 8 is a phosphor coating, and the configuration of each of these parts may be the same as that of the embodiment of the present invention. explain in detail.

In the case of such a structure, as described above,
Since electrons have a property of easily jumping into a portion having a short inter-electrode distance, the anode point is formed at the tip of the auxiliary electrode 20, so that the flying electrons jump into the tip of the auxiliary electrode 20 and the anode point is changed. Since the lamp current is stable and the vibration of the anode is also stable, the lamp lamp current during lighting is stable, and as a result, flicker can be prevented.

However, in the case of the structure in which such an auxiliary electrode 20 is provided, the auxiliary electrode 2 is attached to the internal lead wires 3 and 3.
Since it is necessary to weld 0 and 20 exceptionally, the heat capacity of the entire electrode increases, and the filament temperature decreases near the ends. Therefore, in the cathode mode, the cathode drop voltage increases and the filament coil is applied. Electron emissive materials (emitters) such as barium oxide scatter, accelerating the wear of the emitter,
In addition, there is a problem that it adheres to the bulb and leads to early blackening, which shortens the lamp life.

The auxiliary electrodes 2 are attached to the inner lead wires 3 and 3.
The structure in which 0 and 20 are additionally provided has drawbacks such as an increase in manufacturing cost because the number of parts increases and the number of manufacturing processes such as welding work increases.

Under such circumstances, the technique described in Japanese Patent Laid-Open No. 56-13653 has been proposed as another means for preventing the flicker during lighting. This means enlarges the pitch of the coil portion of the filament coil to some extent.

That is, when the anode point is stably generated in the filament coil, the end portion of the leg portion, that is, the connecting portion (clamp portion) between the leg portion and the internal lead wire is generated rather than the anode point is generated in the coil portion. It is desirable to generate it.
The reason for this is that when the electrons enter the end of the leg portion, the lamp voltage can be lowered as compared with the case where the electrons enter the coil portion, so that the lamp current becomes large and therefore becomes bright.

However, when the pitch of the coil portion of the filament coil is small, the anode glow generated in the anode mode cannot be diffused when switching to the cathode mode, and electrons tend to remain concentrated in the coil portion. Therefore, when the mode is switched to the anode mode again, the coil portion easily becomes the anode point. In this case, since the anode point is always generated in the coil portion, the anode vibration is stable and flicker can be prevented.
When the coil portion becomes the anode point, the lamp voltage becomes relatively large, the lamp current becomes small, and the brightness decreases. Therefore, it is desirable to generate the anode point at the leg portion.

In order to achieve this, the above publication discloses that
By increasing the pitch of the coil part, this allows the glow generated in the coil part in the anode mode to easily diffuse from the large gap of the coil when switching to the cathode mode, thereby making the anode point the coil part. Instead of generating it, it is always generated in the leg portion.

[0013]

However, even if such means are taken, an anode point is still generated in the coil portion, or this anode point fluctuates between the coil portion and the leg portion, so that the anode vibration is generated. Instability and flicker may occur.

The present inventors have studied this point and found that when the filament coil is switched between the anode mode and the cathode mode, the temperature at the coil end changes, which causes a change in the cold resistance value of the filament coil. Is supposed to be caused by.

Therefore, an object of the present invention is to provide a fluorescent lamp that stabilizes the generation point of the anode point generated in the filament coil and prevents flicker during lighting, and an illumination device using the same. Is.

[0016]

According to a first aspect of the present invention, a filament coil provided between a pair of internal lead wires is provided at an end portion of a valve, and the filament coil has leg portions at both ends of the coil portion. In a fluorescent lamp in which these leg parts are connected to the internal lead wires, CR × P ≧ 0.55, where CR is the cold resistance value of the leg parts of the filament coil and P is the pitch of the coil parts. It is characterized by having done.

Here, the cold resistance value means that the filament temperature is 25 ° C. when the electric resistance value CR is measured by a minute current.
The value measured at. The invention of claim 2 is characterized in that the filament coil comprises a double coil.

According to a third aspect of the present invention, the lamp has a lamp current of 250 mA or more. Claim 4
According to another aspect of the present invention, there is provided the fluorescent lamp according to any one of claims 1 to 3, a lighting circuit for lighting the fluorescent lamp, and a lighting fixture to which the fluorescent lamp and the lighting circuit are attached. It is a characteristic lighting device.

[0019]

The present inventors have noticed that the cause of flicker is related to the pitch P of the coil portion of the filament coil and the cold resistance value CR of the leg portion, as described above, and various studies have been made on these relations. I did an experiment. As a result, CR
It has been found that if the condition of × P ≧ 0.55 is satisfied, the anode point does not fluctuate, the anode vibration becomes stable, and flicker can be prevented.

That is, according to the invention of claim 1, CR
Since the condition of × P ≧ 0.55 is satisfied, the occurrence of flicker is prevented. Moreover, in this case, since the anode point is stably generated in the leg portion, the lamp voltage can be relatively reduced, and the current can be increased to improve the brightness.

According to the second aspect of the present invention, particularly when the filament coil is a double coil, the temperature of the leg portion is likely to change and flicker is likely to occur. If the condition described in claim 1 is applied to, the effect becomes remarkable.

According to the invention of claim 3, the lamp current is 2
Since it is 50 mA or more, it is effective when applied to a lamp having a rating of 20 W to 40 W. According to the invention of claim 4, it is possible to provide an illuminating device with less flicker.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. FIG. 2 shows the whole of a straight tube type fluorescent lamp, and reference numeral 1 in the figure is a glass bulb. A flare stem 2 is airtightly joined to the end of the valve 1, and the flare stem 2 closes the end of the valve 1. A pair of internal lead wires 3, 3 are hermetically penetrated through the stem 2. These internal lead wires 3 and 3 are formed of nickel-based wires, and the filament coil 4 is laid over the inner ends of these. The filament coil 4 is made of a tungsten wire, and in the case of this embodiment, a double coil filament is used.

The filament coil 4 has a coil portion 5 having a double coil structure and linear leg portions 6 and 6 composed of a single coil at both ends thereof, and the end portions of the leg portions 6 and 6 are
It is held by the hook portions 7, 7 formed on the internal lead wires 3, 3.

Although not shown, the filament coil 4 is coated with an emitter such as barium oxide.
As shown in FIG. 1, a phosphor coating 8 is formed on the inner surface of the bulb 1, and a predetermined amount of mercury and a rare gas such as argon are enclosed in the bulb 1.

Bases 10, 10 are attached to the ends of the valve 1, and a base pin 11 is attached to the bases 10, 10.
... is projected. The outer end portions of the internal lead wires 3 and 3 are connected to the base pins 11 ...

In such an embodiment, when the cold resistance value of the leg portion 6 of the filament coil 4 is CR (Ω) and the coil pitch of the coil portion 5 is WO (mm), CR × P ≧ 0. It is set in the range of 55. Here, the coil pitch P is
In the case of a double coil, it means the pitch of the secondary coil.
The secondary coil pitch P is 0.4 mm or more and 1.0 mm
The following range is effective, and if it is less than 0.4 mm, it is difficult to manufacture, and if it exceeds 1.0 mm, the function as a filament is impaired.

In the fluorescent lamp having such a structure,
CR of the cold resistance value of the leg portion 6 of the filament coil 4
(Ω) and when the coil pitch of the coil portion 5 is P (mm), the anode point is generated at the connection point between the leg portion 6 and the hook portion 7 because the range is set to CR × P ≧ 0.55. As a result, the fluctuation of the anode point is prevented and the anode vibration is generated.
The disappearance disappears and so-called flicker can be prevented.

That is, the above numerical conditions are: the cold resistance value CR (Ω) of the leg portion 6 and the coil pitch P of the coil portion 5.
Is larger than the conventional one. (Conventional CR x P
Is about 0.3 for the same lamp. ) If the cold resistance value CR of the leg portion 6 is increased, the temperature change due to switching between the anode mode and the cathode mode is reduced, so that the change in the cold resistance value of the filament coil can be reduced and the anode generation point is stable. To do.

Further, if the pitch of the coil portion 5 becomes large, when the glow generated in the coil portion 5 in the anode mode is switched to the cathode mode, it tends to diffuse out from the large gap of the coil portion 5, As a result, the anode point does not occur in the coil portion but always occurs in the leg portion.

From the above, under the above conditions, the anode point is always stably generated in the leg portion 6, and the lamp voltage is relatively higher than that in the coil portion 5 stably. And the lamp current increases. Therefore, the brightness is improved.

The above numerical values are values obtained by experiments by the present inventors, and this experiment will be described. Bulb length 580mm, Bulb inner diameter 28mm, Lamp current 350mA
A plurality of straight-tube fluorescent lamps with a rated input of 20 W were manufactured, and the commercial power source was connected to a commercial power source via a ballast ballast for 20 W and lit.

The filament coil is a double coil made of tungsten and has a wire diameter (FD = filament diameter).
Is a tungsten wire having a diameter of 65 to 80 μm and a primary core wire diameter (MD = primary mandrel diameter) of 180 to 240 μm.
The secondary coil has a primary coil pitch of 120 to 150 μm.
To produce a primary coil, and the primary coil is wound around a secondary winding core having a secondary core diameter of 1500 μm so that the secondary coil pitch P is 0.68 mm. A heavy coil is formed, fired, and then the core wire is melted.

In the lamp, a bulb 1 is filled with a predetermined amount of mercury and 2.4 Torr of argon gas. With respect to such a fluorescent lamp, the electric cold resistance value CR of the end portion of the filament coil, that is, the leg portion 6 was changed, the lamp was lit for 1000 hours, and the flicker occurrence rate at this time was examined. The result is shown in the figure. From FIG. 4, it is clear that the flicker occurrence rate depends on the value of CR × P, and when the ambient temperature close to the practical condition is 40 ° C., if the condition of CR × P ≧ 0.55 is satisfied, , I was able to eliminate the flicker. It was confirmed that flicker did not occur even if the ambient temperature was 60 ° C. if the condition of CR × P ≧ 0.55 was satisfied.

The means for changing the electric cold resistance value CR of the leg portion 6 is to change the wire diameter FD of the filament wire to 1
This can be dealt with by changing the pitch of the next coil. Further, the above fluorescent lamp is effective for a lamp having a lamp current of 250 mA or more and 420 mA or less. This is because a lamp having a lamp current of 250 mA or more and 420 mA or less corresponds to a straight tube fluorescent lamp having a rating of about 10 W to 40 W, and this type of lamp often uses a double coil as a filament coil.

The above flicker is likely to occur remarkably in the case of a double coil. This is because in the case of the triple coil, the leg portion has a double coil structure, the heat capacity is large and the temperature change is small. Therefore, the variation of the anode point is small. On the other hand, in the case of a filament composed of a double coil, the leg portion is composed of a single coil, so that the temperature easily changes,
Therefore, the generation position of the anode point tends to be unstable. Therefore, if the condition of CR × P ≧ 0.55 is applied, it is possible to obtain a remarkable effect in preventing flicker.

A straight tube type fluorescent lamp having a rating of 10 W to 40 W has a bulb outer diameter of approximately 25 mm to 40 mm, and a lamp having a lamp current of 250 mA or more and 420 mA or less has a bulb outer diameter of almost all. It means a lamp of 25 mm to 40 mm.

The valve length is 10 W to 4 W at rated input.
In the case of 0 W, it is 330 mm to 1198 mm. FIG. 5 shows an example of an illuminating device in which the fluorescent lamp of the above embodiment is attached to an illuminating device. That is, in the figure, 20 is a main body of a ceiling-mounted lighting fixture, and lamp sockets 21, 21 are arranged to face each other at both longitudinal ends of the fixture main body 20. The fluorescent lamp 30 shown in FIGS. 1 to 3 is provided between the sockets 21 and 21.
It is attached by engaging 0 and 10. Instrument body 2
A ballast type ballast 22 is housed in 0 as a lighting circuit component for maintaining the starting and stable lighting of the lamp. The fluorescent lamp 30 is connected to a commercial power source (not shown) via the ballast 22.

According to such an illuminating device, the lamp 30 prevents flicker from occurring and the brightness is improved, so that it is possible to provide an illuminating device with less discomfort due to flicker.

The present invention is not limited to the above embodiment. That is, in the above embodiment, the case of the straight tube type fluorescent lamp has been described, but the fluorescent lamp of the present invention is not limited to the straight tube type fluorescent lamp, and other various shapes such as a ring shape, a U shape, a W shape, and a saddle shape. It is also applicable to the fluorescent lamp.

[0041]

As described above, according to the invention of claim 1, since the condition of CR × P ≧ 0.55 is satisfied, the occurrence of flicker is prevented, and the anode point is stable on the leg portion. As a result, the lamp voltage can be relatively reduced, the lamp current is increased, and the brightness is improved.

According to the second aspect of the invention, it is particularly effective when applied to the case where the filament coil is a double coil. According to the invention of claim 3, it is effective when used for a lamp having a lamp current of 350 mA or more. According to the invention of claim 4,
It is possible to provide a lighting device with less flicker.

[Brief description of drawings]

FIG. 1 is a sectional view of an end portion of a straight tube fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a perspective view of the entire fluorescent lamp of the same embodiment.

FIG. 3 is a diagram showing details of a filament coil of the same embodiment.

FIG. 4 is a characteristic diagram showing a relationship between a flicker occurrence rate and a CR × P value.

FIG. 5 is a front view of an illumination device using the fluorescent lamp.

FIG. 6 is a sectional view of an end portion of a conventional fluorescent lamp.

[Explanation of symbols]

1 ... Valve 2 ... Stem 3 ...
Internal lead wire 4 ... Filament coil 5 ... Coil portion 6 ...
Leg part 7 ... Clamp part 20 ... Lighting fixture body

Claims (4)

[Claims] 1. A filament coil provided between a pair of internal lead wires is provided at an end portion of a valve, and the filament coil has leg portions at both ends of the coil portion, and the leg portions are connected to the internal lead wire. In a fluorescent lamp that is wire-connected, when the cold resistance value of the leg portion of the filament coil is CR and the pitch of the coil portion is P, CR × P ≧ 0.55. 2. The fluorescent lamp according to claim 1, wherein the filament coil is a double coil. 3. The lamp has a lamp current of 250 mA.
The above is the fluorescent lamp. 4. A fluorescent lamp according to any one of claims 1 to 3, a lighting circuit for lighting the fluorescent lamp, and a lighting fixture to which the fluorescent lamp and the lighting circuit are attached. A lighting device characterized by the above.