JPH0121587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluorescent lamp lighting device.

Figure 1 shows the structure of a typical rapid-start type fluorescent lamp. That is, the entire inner wall of the glass tube 1 is coated with a transparent metal conductive film (hereinafter referred to as NESA film) 2 to assist in starting the fluorescent lamp. A phosphor 3 is deposited thereon. A mount in which a filament (electrode) 6 is pinched onto an introduction wire 5 embedded in a glass stem 4 is sealed to the glass tube 1 at both ends of the tube. The filament 6 is coated with a suitable electron emissive material. The other end of the lead-in wire 5 is connected to the base pin 7. A predetermined amount of mercury and an inert gas are sealed in a discharge space 8 within the tube.

In addition, the following types of starting aids for fluorescent lamps are included.

External stripe method: A conductive stripe with a width of approximately 3 mm is attached to the entire length of the outer surface of the bulb, and one end is connected to an electrode with high resistance.

Inner stripe method: A conductive stripe with a width of approximately 3 mm is attached to the entire length of the inner wall of the bulb. There is no contact with the electrode.

External silicone method: A water-repellent coating applied to the entire outer wall of the valve.

FIG. 2 shows a leakage type rapid circuit for a single lamp, which is the most common lighting circuit for a rapid start type fluorescent lamp. Reference numeral 9 denotes a rapid start type fluorescent lamp provided with the starting aid described in FIG. 10 is a ballast, and 11 is an electrode preheating winding. 12 is a terminal on the power supply side, and 13 is a terminal on the electrode preheating side.

This lighting circuit uses a rapid start type fluorescent lamp 9 and applies an electrode preheating voltage at the same time as the lamp starting voltage, so that the lamp lights up in 1 to 2 seconds.

Now, regarding the electrode preheating winding 11 shown in FIG. 2, the electrode preheating voltage by this winding 11 is necessary when starting the lamp, but is unnecessary after lighting. This is because after the lamp is lit, a bright spot that becomes a thermionic emission source is created on the power source side of the electrode, and the circuit current is maintained by the thermionic current.
This is because it is no longer necessary to preheat the electrodes using an external circuit.

However, in such a conventional circuit, the electrode preheating voltage remains high even after the lamp is turned on, and the electric power equivalent to electrode preheating is wasted in the ballast. That is, as an example, in a 40W rapid start type fluorescent lamp lighting circuit (Figure 2), the electrode preheating voltage is approximately 4V, and 2.7 to 3.3W of power is wasted even during lighting due to electrode preheating at both ends of the lamp. It was.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rapid start type fluorescent lamp that can reduce electrode preheating power loss.

An embodiment of this invention will be explained with reference to FIGS. 3 to 6. That is, FIGS. 3 and 4 show a first embodiment of the present invention, in which a glass tube 14 is coated with a Nesa film 15 over its entire inner wall, and is further coated with a phosphor 16. A mount in which a filament 20 is pinched at the tip of an introduction wire 18 and a support wire 19 embedded in a glass stem 17 is sealed to the glass tube 14 at both ends of the tube. The filament 20 is coated with a suitable electron emissive material. The other end of the lead-in wire 18 is connected to a base pin 21 on the power supply side. In addition, glass stem 17
A bimetal 23 is attached to the tip of the lead-in wire 22 embedded in the lead-in wire 22 by spot welding.
At room temperature, this bimetal 23 is in contact with the support wire 19 as shown in Figure 3, but the temperature inside the lamp tube is 50°C.
The design is such that when it exceeds this point, it separates from the support line 19 as shown in FIG. The other end of the lead-in wire 22 is connected to a base pin 24 on the electrode preheating side.

A predetermined amount of mercury and an inert gas are sealed in the discharge space 25 inside the tube.

With this structure, when this fluorescent lamp is applied to the lighting circuit shown in FIG. 2, this lighting device operates as follows, and power loss can be reduced.

(1) When the lamp is started, the inside of the tube is at room temperature, so the bimetal 23 is in contact with the support wire 19 of the filament 20. Therefore, when the lamp is started, the electrode preheating voltage is applied to the filament 20, and the lamp is started in the conventional manner (FIG. 3).

(2) When the lamp is turned on, a bright spot is generated on the filament 20, causing the temperature inside the tube to rise. When the temperature inside the tube exceeds 50° C., the bimetal 23 operates, separates from the support wire 19 of the filament 20, and disconnects the electrode preheating circuit (voltage). Power supply side cap pin 2
Since the connection to 1 remains the same, the lamp will not go out and will continue to light (Figure 4).

(3) When the lamp is turned off, the temperature inside the tube decreases, so the bimetal 23 returns to its original state and comes into contact with the support wire 19 of the filament 20 (FIG. 3).

Repeat this below.

FIG. 5 shows a second embodiment of the present invention, in which the bimetal 23 provided between the support line 19 and the lead-in line 22 in the first embodiment is replaced with a bimetal 23. A characteristic thermistor 26 is inserted in series with the filament 20, and other points are the same.

The positive temperature coefficient thermistor 26 has a temperature-resistance characteristic as shown in FIG. 6, and its resistance increases logarithmically when heated to 50 DEG C. or higher.

As a result of this configuration, the lighting device using this fluorescent lamp operates as follows and can reduce power loss.

(1) When the lamp is started, the inside of the tube is at room temperature, so the resistance of the positive temperature coefficient thermistor 26 is very small as shown in FIG. Therefore, when starting the lamp, the electrode preheating voltage is applied to the filament 20, and the lamp starts as usual.

(2) When the lamp is turned on, the resistance of the positive temperature coefficient thermistor 26 increases as shown in FIG. 6 due to an increase in the temperature inside the tube. As a result, the current in the electrode preheating circuit decreases to a negligible magnitude, similar to being interrupted. In other words, the power consumption of the ballast, which corresponds to electrode preheating, is reduced and becomes very small.

(3) When the lamp is turned off, the temperature inside the tube decreases, and the positive temperature coefficient thermistor 26 also returns to its original state.

Repeat this below.

As described above, the fluorescent lamp lighting device of the present invention includes a rapid start type fluorescent lamp, a ballast in which a secondary winding is connected to the power supply side connection terminals of both filaments of this fluorescent lamp, and A normally closed preheating winding provided in the ballast and connected to the filament, and a normally closed device inserted in series on the side opposite to the power supply side connection terminal of the filament and opened upon detecting a temperature rise within the fluorescent lamp. Since it is equipped with a type switch, it has the following effects.

That is, discharge is started by the voltage of the secondary winding and the preheating current of the preheating winding, and the temperature rise inside the fluorescent lamp is detected by the normally closed switch, and the normally closed switch operates to energize the preheating winding. This reduces power loss caused by the ballast's preheating winding, contributing to energy savings.

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view of a conventional rapid-start type fluorescent lamp, Figure 2 is its circuit diagram, and Figure 3 is a partially cutaway side view of a conventional rapid-start type fluorescent lamp.
4 and 4 are respectively a cutaway sectional view of the first embodiment of the present invention, FIG. 5 is a cutaway sectional view of the second embodiment, and FIG. 6 is a characteristic diagram of the main part thereof. 9...Rapid start type fluorescent lamp, 10
... Ballast, 11 ... Electrode preheating winding, 12 ...
Power supply side terminal, 13... Electrode preheating side terminal, 20...
... filament, 23... bimetal switch (normally closed switch), 26... positive characteristic thermistor (normally closed switch).

Claims (1)

[Scope of Claims] 1. A rapid start type fluorescent lamp, a ballast having a secondary winding connected to the power supply side connection terminals of both filaments of the fluorescent lamp, and a ballast provided in the ballast with a secondary winding connected to the power supply side connection terminals of both filaments of the fluorescent lamp. and a normally-closed switch inserted in series on the opposite side of the filament to the power supply side connection terminal, which operates to open upon detecting a temperature rise within the fluorescent lamp. Light lighting device. 2. The fluorescent lamp lighting device according to claim 1, wherein the switch is a bimetal switch. 3. The fluorescent lamp lighting device according to claim 1, wherein said switch comprises a positive temperature coefficient thermistor.