JP2613688B2 - Light emitting electron tube lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a light emitting electron tube lighting device in which a light emitting gas sealed in a tube is excited by collision of accelerated electrons to emit light.

[0002]

2. Description of the Related Art Conventionally, a light emitting electron tube in which a light emitting gas sealed in a tube is excited by collision of accelerated electrons to emit light is disclosed in Japanese Patent Application Laid-Open No. 58-145055.
There are those shown in. As shown in FIG. 4, the light-emitting electron tube has a low-pressure light-emitting gas sealed therein, and has a light-transmitting glass tube 1 coated with a fluorescent substance 2 on its inner surface, and electrodes 3A provided inside the tube 1. 3B, the electrons emitted from the cathode electrode 3A of the heat radiation type electrode are accelerated by the anode electrode 3B and collide with the encapsulated light emitting gas, and the collision excites the light emitting gas to ionize and emit light. Is to cause.

[0003] Since the distance between the electrodes (several millimeters to several centimeters) is short, the light emitting region extends to the space behind the anode. Actually, the cathode and anode alternate with 3A and 3B because an alternating current is used as the lighting power supply voltage. Further, mercury vapor of several millitorr and rare gas of several torr are sealed as the light emitting gas inside the tube 1. Because of the short distance between the electrodes, the light-emitting electron tube has a feature that the lamp voltage is low.

For this reason, in order to obtain a lighting power supply voltage for lighting the light-emitting electron tube, for example, AC 100 V must be reduced to ten and several volts, and it is necessary to use a transformer or a capacitor as a step-down means. However, both have a problem that the capacity is large and the cost is high. Therefore, high-frequency lighting can be considered. However, as a characteristic of the light-emitting electron tube, there is a problem in that efficiency (output) is reduced by about 20% when commonly used sine waves are used for high-frequency lighting.

That is, the lighting power supply voltage waveform (a) -lamp voltage waveform (b) and the lamp voltage waveform (b) -lamp current waveform (c) when the lamp is lit with a 60 Hz sine wave are shown in FIGS. FIG. 7 shows a lighting power supply voltage waveform (a) ′-lamp voltage waveform (b) ′ and a lamp voltage waveform (a) ′-lamp current waveform (c) when lighting is performed with a sine wave of 40 KHz. As shown in FIG.

As can be seen from FIG. 5, at 60 Hz, the rising portion of the lighting power supply voltage waveform (a) coincides with the rising portion of the lamp voltage waveform (b). However, as shown in FIG. Lighting power supply voltage waveform (A) '
It can be seen that the rising portion of the ramp voltage waveform (b) ′ is considerably lower than the rising portion of the curve. As can be seen from FIGS. 6 and 8, the lamp current is discontinuous at 60 Hz, but is continuous at 40 KHz.

These can be interpreted as follows. 60Hz
In this case, since the time required for electrons to disappear by diffusion is faster than the time when the lamp voltage is lower than a certain voltage (discharge sustaining voltage), the electron density becomes discontinuous, and as a result, the lamp current becomes discontinuous. Therefore, at the start of the next cycle, the light-emitting electron tube is not lit. Therefore, until the voltage applied between the electrodes of the light-emitting electron tube reaches the starting voltage, it is synchronized with the lighting power supply voltage waveform (a).

On the other hand, at 40 KHz, the electron density always has a positive value because the time when the lamp voltage is lower than a certain voltage (discharge sustaining voltage) is shorter than the time until the electrons disappear by diffusion. Therefore, the lamp current becomes continuous. In this case, when the lighting power supply voltage waveform (a) 'rises, the electron density is higher than the required current value, so that the electric field of the light emitting electron tube (that is, the lamp voltage) may be low. That is, when I = enμE, [I] is not so large at the time of rising and [n] is large, so that
[E] may be small. It turns on the power supply voltage waveform (a)
This is the reason why the lamp voltage is low at the time of rising. For this reason, at 40 KHz (because the lamp current is the same and the lamp voltage is low) as compared with 60 Hz, the power input to the light emitting electron tube is small, and the electric field is low at the rising portion of the lighting power supply voltage waveform (a) ′. In this case, light emission hardly occurs, and the efficiency is low.

[0009]

As described above, there is a problem that the efficiency is reduced when the light-emitting electron tube is lit at a high frequency with a generally used sine wave. The very disadvantageous rate has been a problem in the development of light emitting electron tubes.

[0010] The present invention has been made in view of the above problems, and an object thereof is to reduce the efficiency without reducing the efficiency.
An object of the present invention is to provide a light emitting electron tube lighting device capable of lighting a light emitting electron tube at high frequency.

[0011]

According to the present invention, in order to achieve the above object, a low-pressure rare gas and mercury vapor are sealed in a light-transmitting gas inside a light-transmitting tube, and the tube is sealed. In a light-emitting electron tube in which a pair of thermionic emission type electrodes are arranged at intervals of several millimeters to several centimeters, the polarity of both electrodes is alternately changed at a high frequency, and the electrons emitted from the cathode electrode are converted to the anode. In the light emitting electron tube lighting device which accelerates the light by the electrodes and causes the accelerated electrons to collide with the light emitting gas to excite and emit the light emitting gas, the rising time of the two electrodes of the light emitting electron tube is longer than the energy relaxation time of the light emitting electron tube. Is provided with lighting power supply means for applying a voltage having a short waveform.

[0012]

According to the present invention, there is provided a lighting power supply means for applying a voltage having a waveform whose rise time is shorter than the energy relaxation time of the light emission electron tube to both electrodes of the light emission electron tube,
Since the waveform of the lighting power supply voltage rises steeply, a large lamp current is required at the time of the rise, and as a result, the power input to the light-emitting electron tube also increases, and efficiency is always increased because a high electric field is applied inside the light-emitting electron tube. It gets better.

[0013]

The present invention will be described below with reference to examples. FIG.
2 shows a circuit configuration of an embodiment of the present invention. In this embodiment, a lighting power supply voltage of a rectangular wave of 40 KHz shown in FIG. The voltage is applied between the L electrodes 3A and 3B.

As the light emitting electron tube L, 2 Torr of argon and several milliTorr of mercury vapor are used as the light emitting gas.
The rated current enclosed in the tube 1 having the structure shown in FIG.
6A is used. Thus, the lamp voltage waveform (b) -lamp current waveform (c) 'when the light emitting electron tube L is lit by the lighting device of the present invention is as shown in FIG. As can be seen from FIG. 3, the lamp current waveform (c) '
And the lamp voltage waveform (b) ′ are almost synchronized. That is, since the rising of the lighting power supply voltage waveform is steep, a large lamp current is rapidly required at the time of rising. Therefore, when I = enμE, a large [I] is required at the time of rising. On the other hand, [n] is large, but [E] is also large because the required [I] is large. This is the reason why the rise of the lamp voltage becomes sharp in synchronization with the lamp current. Thereby, the power input to the light-emitting electron tube L also increases, and the efficiency is improved because a high electric field is always applied to the inside of the light-emitting electron tube L. In addition, the output is large because there is no dead time as in the case of 60 Hz. If the efficiency is 100% in the case of a sine wave and a lighting power supply voltage waveform of 60 Hz, a sine wave and 40 KH
The efficiency for the lighting power supply voltage waveform of z is as low as 79%,
In the case of a lighting power supply voltage waveform having a rectangular wave and 40 KHz as in the lighting device of the present invention, the efficiency was as high as 115%.

Although a rectangular wave is used in the above embodiment, as a practical matter, the steepness of the rising of the voltage waveform is as follows.
There is no problem if it is shorter than the energy relaxation time of the used light emitting electron tube. This energy relaxation time is several μsec in the light emitting electron tube L used in the present embodiment, but differs depending on the type and pressure of the gas filled in the light emitting electron tube used. Therefore, the lighting power supply voltage waveform used in the lighting device of the present invention is not particularly limited to a rectangular wave.

[0016]

According to the present invention, since the lighting power supply means for applying a voltage having a waveform whose rise time is shorter than the energy relaxation time of the light emitting electron tube to both electrodes of the light emitting electron tube is provided, the present invention is also applicable to high frequency lighting. There is an effect that the light-emitting electron tube can be turned on without lowering the efficiency.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing one embodiment of the present invention.

FIG. 2 is a waveform diagram showing a waveform of a lighting power supply voltage used in one embodiment of the present invention.

FIG. 3 is an explanatory diagram of a lamp voltage-current waveform of a light emitting electron tube used in one embodiment of the present invention.

FIG. 4 is a partially broken perspective view showing the configuration of the light emitting electron tube.

FIG. 5 is an explanatory diagram of a lighting power supply voltage waveform-lamp voltage waveform of a conventional example when a 60 Hz sine wave is used.

FIG. 6 is an explanatory diagram of a lamp voltage waveform-lamp current waveform of a conventional example when a 60 Hz sine wave is used.

FIG. 7 is an explanatory diagram of a lighting power supply voltage waveform-lamp voltage waveform of a conventional example when a 40 KHz sine wave is used.

FIG. 8 is an explanatory diagram of a lamp voltage waveform-lamp current waveform of a conventional example when a 40 KHz sine wave is used.

[Explanation of symbols]

 L Light emitting electron tube 3A electrode 3B electrode 4 Oscillator 5 Amplifier

Continuation of the front page (56) References JP-A-61-284051 (JP, A) JP-A-1-102846 (JP, A) JP-A-4-133293 (JP, A) JP-A-4-223097 (JP) , A) JP-A-1-102848 (JP, A)

Claims (1)

(57) [Claims] 1. A low-pressure rare gas and mercury vapor are enclosed in a light-transmissive tube as a light-emitting gas, and a pair of thermoelectron-emitting electrodes are provided in the tube within a range of several millimeters to several centimeters. The polarities of both electrodes of the light emitting electron tube arranged at intervals are alternately changed at a high frequency, the electrons emitted from the cathode electrode are accelerated by the anode electrode, and the accelerated electrons collide with the light emitting gas. A light emitting electron tube lighting device for exciting the light emitting gas to emit light by providing a lighting power supply means for applying a voltage having a waveform whose rise time is shorter than the energy relaxation time of the light emission electron tube to both electrodes of the light emission electron tube. Light emitting electron tube lighting device.