JPH07296975A - Fluorescent lamp lighting method - Google Patents

Abstract

PURPOSE:To enhance operating efficiency of a fluorescent lamp. CONSTITUTION:A fluorescent lamp is fitted with inner electrodes 5a, 5b installed in the discharge space 4 between a tube 2 and an internal tube 3 and an outer electrode 6 installed on the inside wall of the internal tube 3, wherein discharging takes place between the inner electrodes 5a, 5b, and a pulse voltage is impressed between the outer electrode 6 and inner electrode 5a. The frequency of pulse voltage is made C1.trC<2>.eC3J where tr is the rising time of pulse voltage, J is current density in discharging between inner electrodes 5a, 5b, C1 is a constant between 1 and 5, C2 is a constant between -0.8 and -0.2, and C3 is a constant between -4 and -1, electrons having a high energy level can be produced by energizing undulation in the discharge plasma, which ensures enhancement of the lamp efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called fluorescent lamp in which mercury and a rare gas are enclosed in a tube.

[0002]

2. Description of the Related Art The structure of a fluorescent lamp described in USP 5,053,933 is shown in FIG. FIG. 3 is a sectional view of the fluorescent lamp. In the figure, reference numeral 1 is a discharge tube, and an outer tube 2 with one end blocked.
It is integrally formed with an internal pipe 3 which is disposed inside the pipe 2 and extends in the axial direction of the pipe 2 and whose one end is closed. The opening at the other end of the tube 2 is connected to the opening at the other end of the internal tube 3 to form a sealed space. A space surrounded by the tube 2 and the inner tube 3 is a discharge space 4, and mercury and a rare gas are enclosed in the discharge space 4. A pair of internal electrodes 5a and 5b, which are hot cathodes, are formed near both ends inside the discharge space 4. The internal electrodes 5a are arranged in a substantially arc shape inside the discharge space. An outer electrode 6 which is a substantially cylindrical conductive electrode is formed on the inner wall of the inner tube 3. A voltage having a commercial frequency is applied between the internal electrodes 5a, 5b of the fluorescent lamp thus configured to light the internal electrodes 5a, 5b.
US Pat. No. 5,053,933, it is possible to obtain a high-efficiency lamp with a lamp efficiency exceeding 150 lm / W by applying a high-frequency pulse voltage with a fast rise time between one of the electrodes b and the external electrode 6.
It is described in. The pulse voltage applied in this case is
The frequency is 35 kHz, the rise time of the pulse voltage is 10 ^-9 se
It is about c. Furthermore, it is said that the shorter the rise time of the pulse voltage, the higher the efficiency.

[0003]

However, the rise time of the pulse voltage, which is an important point for realizing the high-efficiency lamp described above, is set to about 10 ^-9 sec because the pulse voltage generating pulse is generated. This was very difficult considering that the circuit is a power circuit.

The present invention has been made in view of the above problems.
The purpose is to improve the efficiency by applying a pulse voltage slower than 10 ^-9 sec between one of the internal electrodes and the external electrode for a fluorescent lamp with the same configuration as the fluorescent lamp described in USP 5,053,933. Another object of the present invention is to provide a method of lighting a fluorescent lamp that can achieve the above.

[0005]

[Means for Solving the Problems]
Therefore, the method of lighting the fluorescent lamp of the present invention is
And an inner pipe extending in the axial direction of the pipe, which is arranged in
And arranged near both ends of the discharge space formed between the inner tube and
Placed on the inner wall of the inner tube with a pair of hot cathodes
A pair of conductive electrodes and installed in the discharge space
While performing a discharge between the hot cathode of, and the conductive electrode
A fluorescent lamp that applies a pulse voltage to one of the hot cathodes.
The lamp's lighting method, the rise of the pulse voltage
Time t_rAnd the current density of the discharge between the hot cathodes is J and
The constant C1 is 1 to 5, and the constant C2 is -0.8 to -0.2.
Then, the constant C3 is set to -4 to -1, and the frequency of the pulse voltage is set to C1.
・ T_r ^C2・ e^C3JIt is characterized by
It

[0006]

When a pulse voltage having a sharp rise is applied to the discharge space in which the discharge plasma exists, electrons with high energy can be generated inside the discharge plasma. These electrons allow the excitation of mercury to higher levels. Mercury excited to this higher level emits during the pulse dwell time. This is the same phenomenon as the afterglow in the generally-known pulse discharge, and if the conditions of the applied pulse voltage are optimized, a larger radiation intensity than that during the application of the pulse voltage can be obtained.

Further, in accordance with the plasma density (electron density) generated by the discharge between the internal electrodes which are hot cathodes,
By optimizing the frequency of the applied pulse voltage,
Waves can be excited inside the discharge plasma.
The presence of this wave increases the probability of excitation to the 254 nm emission level, resulting in an increase in the 254 nm emission intensity.

When the frequency of the pulse voltage is F _p (Hz), the rise time of the pulse voltage is t _r (sec), and the current density of the discharge between the internal electrodes inside the discharge space is J (mA / mm ² ), By setting the frequency F _{p of the} pulse voltage as shown in the diagram in Fig. 2, the efficiency improvement equivalent to that when the rise time of the pulse voltage is set to about 10 ^-9 sec in the fluorescent lamp described in USP 5,053,933 is achieved. I was able to plan.

Therefore, from the diagram shown in FIG. 2, a high-efficiency lamp can be obtained by setting the frequency F _{p of the} applied pulse as the following equation.

[0010]

[Equation 1]

[0011]

FIG. 1 shows an embodiment of a method for lighting a fluorescent lamp according to the present invention. FIG. 1 is a circuit diagram of a lighting circuit using the fluorescent lamp shown in FIG. However, the same components as those shown in FIG. 3 are designated by the same reference numerals. In FIG. 1, a discharge tube 1 of a fluorescent lamp is formed by integrally forming an outer tube 2 and an inner tube 3 arranged inside the tube 2 and extending in the axial direction of the tube 2. The opening at the other end of the tube 2 is connected to the opening at the other end of the internal tube 3 to form a sealed space. A space surrounded by the tube 2 and the inner tube 3 is a discharge space 4, and mercury and a rare gas are enclosed in the discharge space 4. A pair of internal electrodes 5a and 5b, which are hot cathodes, are formed near both ends inside the discharge space 4. Internal electrode 5a
Are arranged in an arc shape inside the discharge space 4. A substantially cylindrical outer electrode 6, which is a conductive electrode, is formed on the inner wall of the inner tube 3. The internal electrodes 5a and 5b of the fluorescent lamp thus configured are connected to the output of the lighting circuit 8 connected to the commercial power supply 7. The frequency of the output voltage of the lighting circuit 8 is not limited to the commercial frequency. further,
The lighting circuit 8 may be configured to output a DC voltage. The inner electrode 5a, which is one of the hot cathodes, and the outer electrode 6, which is a conductive electrode, are connected to the output of the pulse generation circuit 9 that outputs a pulse voltage.

In the lighting circuit configured as described above, a DC voltage is applied between the inner electrodes 5a and 5b by the lighting circuit 8 to light the fluorescent lamp, and the inner electrode 5a and the outer electrode 6 are lit.
The lamp efficiency can be improved by applying a pulse voltage between (for example, a metal film).

For example, the internal electrodes 5a, 5 inside the discharge space
A DC voltage of 200 mA is applied by applying a DC voltage between points b, and a pulse voltage with a rise time of about 10 ^-6 sec is applied at a frequency of 700
It is applied between the inner electrode 5a and the outer electrode 2 at Hz. At this time
The time average of the 254 nm radiation intensity is about 1.3 times the value when no pulse voltage is applied, and the power input from the pulse generation circuit 9 to the fluorescent lamp is about 10% of the DC discharge power. Therefore, the rise time of the pulse voltage is
When the frequency is 700 Hz for about 10 ^-6 sec, the radiation efficiency of 254 nm radiation increases by about 20%.

The shapes of the fluorescent lamp tube and the internal tube, the internal electrodes and the external electrodes shown in the embodiments are not limited to the embodiments.

[0015]

As described above, according to the fluorescent lamp of the present invention, a discharge space is formed between the tube and the internal tube formed inside the tube, and a voltage is applied between the internal electrodes to turn on the external light. This is a fluorescent lamp in which pulse voltage is applied from the electrodes, and a pulse voltage with an optimized frequency is applied to excite the waves inside the discharge plasma and generate electrons with a high energy level, thereby raising the pulse voltage. Even if the time is slower than 10 ^-6 sec, the fluorescent lamp can be turned on with high efficiency.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a fluorescent lamp lighting method according to the present invention.

FIG. 2 is a diagram showing the relationship between the frequency of the pulse voltage applied to the fluorescent lamp of the present invention, the rise time of the pulse voltage, and the current density of the discharge between the internal electrodes (hot cathodes).

FIG. 3 is a cross-sectional view showing an example of a fluorescent lamp.

[Explanation of symbols]

 2 tube 3 internal tube 4 discharge space 5a, 5b internal electrode (hot cathode) 6 external electrode (conductive electrode)

Claims (1)

[Claims] 1. A tube, an inner tube disposed inside the tube and extending in the axial direction of the tube, and a pair of hot cathodes disposed near both ends of a discharge space formed between the tube and the inner tube. ,
With a conductive electrode arranged on the inner wall of the inner tube, while performing a discharge between the pair of hot cathodes installed in the discharge space, between the conductive electrode and one of the hot cathodes. In the method of lighting a fluorescent lamp applying a pulse voltage, the rise time of the pulse voltage is t _r , the current density of the discharge between the hot cathodes is J, and the constant C1 is 1 to 5
, The constant C2 is -0.8 to -0.2, the constant C3 is -4 to -1, and the frequency of the pulse voltage is C1 · t _r ^C2 · e A method of lighting a fluorescent lamp, which is ^C3J .