JPH06283134A - High-frequency-lighted fluorescent lamp, its lighting device, and starting method - Google Patents

Abstract

PURPOSE:To ensure a start, prevent the spattering of a filament material, and reduce the occurrence of blackening on a tube wall by setting the resistance of filaments of a fluorescent lamp within a specific ratio range between that during preheating and that before preheating. CONSTITUTION:When the lighting device of a lamp 1 is connected to a power source, a high-frequency current is fed to filaments 3 from a driving circuit 20 to start preheating. The pulse voltage is generated by a starting timer circuit 30 after a prescribed period from the start of preheating and applied to the filaments 3. The resistor R1 of the filaments 3 during preheating is set to 4-6 times the resistor R0 before preheating, the filaments 3 are heated to about 700-900 deg.C, and an electric discharge is surely started between the filaments 3. The spattering of an emitter applied to the filaments 3 and a filament material is prevented, the blackening on a tube wall is prevented, and the maintenance ratio of the light flux can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency lighting fluorescent lamp, a lighting device therefor, and a starting method.

[0002]

2. Description of the Related Art Generally, a fluorescent lamp used at a commercial frequency is equipped with a lighting tube (a glow starter). When a lamp is started, a temperature of the filament gradually rises when a preheating current is applied to the filament. During this process, a current also flows through the ignition tube, the bimetal electrode is thermally deformed, and the bimetal electrode contacts the fixed electrode. When the bimetal electrode of the lighting tube separates from the fixed electrode at the timing when the filament reaches a so-called end glow state in which the filament is sufficiently preheated and emits a large amount of thermoelectrons, the kick voltage (discharge starting voltage) at this time Is applied to the filament to start the discharge. in this case,
The starting time from the start of preheating to the start of discharge is set to 1 to 2 seconds. The starting time is set based on the time required for the filament to be preheated to reach the end glow state and the time required for the bimetal electrode of the ignition tube to be thermally deformed to generate the kick voltage. In this case, the filament is preheated sufficiently to raise the temperature to a saturated state so that the lamp is surely started by the kick voltage generated at the beginning of the ignition tube. Therefore, a fluorescent lamp that is lit at this type of commercial frequency requires 1-2 seconds to start.

On the other hand, recently, high frequency lighting has been adopted to increase the luminous efficiency of the lamp.
In the case of a high-frequency lighting fluorescent lamp, high-frequency power is supplied from the drive circuit (inverter), the anode drop voltage is reduced, and the loss during lighting is reduced, resulting in higher efficiency. However, in this case, since the anode drop voltage becomes small, it is difficult to raise the filament temperature at the time of starting. Nevertheless, the feature is that the starting time is short (0.2 to 1.0 seconds). The reason why the starting time can be shortened is that since the lighting tube is not used, the application timing of the discharge start voltage is not restricted by the operating time of the lighting tube and can be selected relatively freely.

[0004]

However, in the conventional high-frequency lighting fluorescent lamp, since the preheating time is short when the discharge starting voltage is applied, the filament may not be sufficiently preheated. If a high starting voltage is applied without being sufficiently preheated, the emitter coated on the filament and the filament material itself will be knocked out and sputtering will occur, causing blackening of the tube wall early and reducing the luminous flux. is there.

The present invention has been made in view of the above circumstances. An object of the present invention is to match the preheating temperature of the filament at the time of starting and the application timing of the discharge starting voltage to enable reliable starting. It is an object of the present invention to provide a high-frequency lighting fluorescent lamp, a lighting device therefor, and a starting method capable of preventing the sputtering of an emitter or filament material and reducing the occurrence of blackening of the tube wall.

[0006]

A high-frequency lighting fluorescent lamp according to claim 1 has a resistance characteristic of a filament,
The ratio of the resistance R ₁ during preheating to the resistance R ₀ before preheating is R ₁ /
It is characterized in that it is set such that R ₀ = 4 to 6.

According to another aspect of the present invention, there is provided a lighting device for a high-frequency lighting fluorescent lamp, wherein a driving circuit for supplying high-frequency power to the fluorescent lamp and a resistor R ₁ for preheating the filament at the time of starting the fluorescent lamp are preheated. For the previous resistor R ₀ ,
A starting circuit that applies a discharge starting voltage to the filament when R ₁ / R ₀ = 4 to 6 is reached is provided.

According to a third aspect of the present invention, there is provided a method for starting a high frequency lighting fluorescent lamp, wherein at the time of starting, the resistance R _{1 of the} fluorescent lamp during filament preheating is R ₁ / R ₀ with respect to the resistance R ₀ before preheating. The discharge start voltage is applied to this filament when the range of 4 to 6 is reached.

[0009]

According to the present invention, in any one of claims 1 to 3, the ratio R ₁ / R ₀ of the resistance R ₁ during preheating of the filament and the resistance R ₀ before preheating is in the range of 4 to 6. Since the discharge start voltage is applied in this state, the discharge start voltage is applied when the temperature of the filament is sufficient to start the discharge, and the discharge starts smoothly and reliably. Therefore, sputtering of the emitter or filament material is prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. FIG. 1 shows a high-frequency lighting fluorescent lamp. As is known, the lamp 1 has filaments 3 and 3 sealed at both ends of an arc tube bulb 2, and a phosphor coating (not shown) is formed on the inner surface of the bulb. Is configured.
A rare gas such as mercury and argon is enclosed in the arc tube. Although not shown in detail, the filaments 3 and 3 are formed into a triple coil with a tungsten wire.
An emitter made of an oxide mainly composed of strontium and calcium is applied. The above construction may be the same as the conventional one, but the resistance characteristics of the filaments 3 and 3 are such that the resistance R ₁ when a preheating current is applied to this filament and the resistance R when the preheating current is not applied are cold. ₀ and the ratio of, R ₁ / R ₀ is set to be in the range of 4-6. Here, for example, when the starting time is set to 1.0 second, the resistance R ₁ of the filament is 4 seconds after the preheating current is passed 1.0 seconds after the resistance R ₀ when the preheating current is not passed.
It is set to be ~ 6 times. According to the experiments conducted by the present inventors, the optimum preheating temperature (filament temperature when the starting voltage is applied to start the discharge) depends on the level of the discharge starting voltage, but is preferably about 700 to 900 ° C. By selecting the resistance characteristic by means of changing the number of turns of the coil, for example, when a predetermined preheating current is passed, the filament temperature is 700 to 9 after 1.0 second.
The temperature is set to reach 00 ° C.

The lamp 1 is connected to a lighting device and lit. The circuit structure of the lighting device is shown in FIG. 1, in which 10 is a smoothing circuit, 20 is a drive circuit corresponding to a high-frequency oscillation circuit (inverter), and 30 is a starting timer circuit.

The AC power having a commercial frequency of 50 Hz or 60 Hz supplied from the commercial power supply 40 is converted into a DC component by the smoothing circuit 10, and a high frequency oscillating action of the drive circuit 20 generates a high frequency power of, for example, 50 kHz. Are supplied to the lamp 1.

In the starting timer circuit 30, a pulse voltage is generated after a predetermined time from the start of preheating, and this pulse voltage is applied to the filament 3 as a discharge starting voltage. . For example, the starting timer circuit 30 is set to apply a pulse voltage to the filament to start the discharge 1.0 second after starting preheating.

According to this structure, when the lighting device is connected to the power source to start the lamp 1, a high frequency current is sent from the drive circuit 20 to the filaments 3 and 3, and the filaments 3 and 3 start preheating. At this time, in the starting timer circuit 30, a pulse voltage is generated after a predetermined time from the start of preheating, and this pulse voltage is applied to the filaments 3 and 3. At this time, the filaments 3 and 3 are set such that the resistance R ₁ during preheating is 4 to 6 times the resistance R ₀ before preheating, so that the filament temperature is 700 to 9
The temperature has risen to about 00 ° C. Therefore, since the pulse voltage is applied from the starting timer circuit 30 to the filaments 3 and 3 in this state, discharge is reliably started between the filaments 3 and 3.

Therefore, the emitter applied to the filament and the filament material are prevented from being sputtered, are prevented from adhering to the tube wall to cause blackening, and the luminous flux maintenance factor is increased. The results of the present invention confirmed by experiments will be described.

The fluorescent lamp used in the experiment has an inner diameter of 10.
3 mm, electrode distance 485 mm, rated lamp current 350 m
A, the lamp voltage is 60 V, and the cold resistance of the filament is 3 Ω.

The lighting device is driven by the drive circuit 20 at 50 kHz.
It is designed to generate high frequency power of z and has a preheating current of 280 mA. The starting timer circuit 30 is adapted to generate a pulse voltage 1.0 seconds after the start of preheating.

In the case of such a constitution, the relationship between the preheating time and the filament temperature was measured, and the results shown in FIG. 2 were obtained. That is, in FIG. 2, the preheating time is 0.
After 9 to 1.1 seconds, the filament temperature T is 750 to 870.
Reached ℃. The filament resistance R ₁ measured at this time was 11.8 to 18.3. That is, the filament resistance R ₁ of the filament is 11.8 to 18.3 (R ₁ / R ₀ = 0.95 to 1.1 seconds after the preheating is started).
3.9 to 6.1) and the filament temperature T is 750.
~ 870 ° C was reached.

When the occurrence of blackening was examined for such a lamp 1, the characteristics shown in FIG. 3 were obtained. In FIG. 3, it can be seen that the characteristic a is the lamp and the lighting device of the present invention used in the above experiment, and from this characteristic, the occurrence of blackening is reduced and a good luminous flux maintenance factor can be obtained for a long period of time. On the other hand, the characteristic b in FIG. 3 is obtained when the resistance characteristic R ₁ / R ₀ of the filament is 3 and the starting timer circuit 3 is used.
It is a characteristic of a lamp using a lighting device that does not have 0, and it can be seen that blackening occurs early.

It should be noted that the temperature rise of the filament varies depending on the preheating current.
When the current is set to 00 mA, the time required to reach 700 to 900 ° C. is 0.7 to 0.
It can be shortened to 8 seconds and the preheating current is 1000 m.
When set to A, the preheating time can be shortened to 0.4 to 0.5 seconds. Therefore, increasing the preheating current is also one means for shortening the starting time. However,
If only the preheating current is increased, the lighting device becomes complicated and expensive.

The present invention is not limited to the above embodiment. That is, the present invention is not limited to the rating of the lamp used in the experiment, and can be applied to a fluorescent lamp that is lit at high frequency. For this reason, the shape of the lamp is not particularly limited, and it can be applied to high-frequency lighting fluorescent lamps of various shapes such as a straight tube shape, a bent shape, and a compact shape.

[0022]

As described above, according to the present invention, in any one of claims 1 to 3, the ratio R ₁ / R ₀ of the resistance R ₁ during preheating of the filament and the resistance R ₀ before preheating is Four
Since the discharge start voltage is applied to this filament in the range of ~ 6, the filament is in a temperature condition sufficient to start discharge, and the filament preheating temperature and the application timing of the start voltage match. Therefore, since the discharge start voltage is applied when a large amount of thermoelectrons are emitted, the discharge can be started smoothly and surely. Therefore, the harsh use of applying a forcible voltage to the filament to forcibly discharge the filament is eliminated, and the sputtering of the emitter or filament material is prevented. As a result, the blackening of the tube wall is reduced, and the luminous flux maintenance factor can be improved.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a high-frequency lighting fluorescent lamp and a lighting device therefor according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a filament preheating time and a filament temperature in the example.

FIG. 3 is a characteristic diagram showing the number of times the lamp blinks and how blackening occurs in the embodiment.

[Explanation of symbols]

1 ... High frequency lighting fluorescent lamp 2 ... Bulb
3 ... Filament 10 ... Smoothing circuit 20 ... Drive circuit 30 ... Start-up timer circuit

Claims (3)

[Claims] 1. A high-frequency lighting fluorescent lamp which is lit by supplying high-frequency power from a high-frequency lighting device, wherein the filament of the fluorescent lamp has a resistance R ₁ during preheating.
And a resistance R ₀ before preheating, which has resistance characteristics such that R ₁ / R ₀ = 4-6. 2. A lighting device for supplying high-frequency power to a high-frequency lighting fluorescent lamp, comprising: a drive circuit for supplying high-frequency power to the fluorescent lamp; and a resistance R ₁ at the time of filament preheating at the time of starting the fluorescent lamp. Is R ₁ / R ₀ = 4 against the resistance R ₀ before preheating
A lighting device for a high-frequency lighting fluorescent lamp, comprising: a starting circuit that applies a discharge starting voltage to the filament when the range reaches -6. 3. A method of starting a high-frequency lighting fluorescent lamp which is lit by being supplied with high-frequency power from a high-frequency lighting circuit, wherein the resistance R _{1 of the} fluorescent lamp at the time of preheating is a resistance R before preheating. _{For 0} , R ₁ / R ₀ = 4
A method for starting a high-frequency lighting fluorescent lamp, characterized in that a discharge starting voltage is applied to this filament when the range reaches -6.