JPH0537401Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rare gas fluorescent lamp that has excellent start-up performance at startup.

[Prior art and its problems]

Fluorescent lamps filled with mercury vapor have excellent properties such as low power consumption and high luminous efficiency, so they have recently been used in a wide variety of applications, one of which is as a light source for facsimile machines. It is also used for Since facsimiles can be received even in unmanned offices at night, they are used in cold regions even when the environmental temperature is close to zero.
However, the amount of light from a fluorescent lamp filled with mercury vapor is highly dependent on the environmental temperature, and at low temperatures, the vapor pressure of mercury is extremely low, resulting in an extremely low amount of light. For this reason, a rare gas fluorescent lamp filled with a rare gas such as xenon is used instead of mercury vapor. This rare gas fluorescent lamp has almost no dependence on environmental temperature, and its light intensity hardly decreases even at low temperatures.However, xenon gas cannot have the same Penning effect as mercury vapor, so its luminous efficiency is lower than that of mercury fluorescent lamps. , the lighting performance is also rather poor. By the way, when receiving signals in an unmanned office at night, the fluorescent lamps will start immediately when receiving the received signal, e.g.
It is necessary to light up in a steady state and become ready for reception within a short time of 100 msec, but in a dark atmosphere at night, the start-up is slow and it is difficult to meet this requirement. Although increasing the starting voltage improves the start-up performance at startup, it also increases power consumption and requires increasing the withstand voltage of the device, which increases the size and weight of the device and increases cost. For this reason, for example, radioactive substances such as nickel isotopes are used for electrodes, or backup lights are always turned on near the fluorescent lamps to eliminate the dark atmosphere. However, if radioactive materials are used in the electrodes, care must be taken in management and handling, and if the backup light is always on, power consumption will increase.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rare gas fluorescent lamp that lights up in a steady state immediately after starting and has excellent start-up performance even when the starting voltage is low.

[Structure of the idea and its effects]

The rare gas fluorescent lamp of the present invention includes a pair of main electrodes that are placed opposite to each other at both ends of an arc tube filled with a rare gas, and one main electrode that is placed close to each other in a non-contact state.
An auxiliary electrode connected to the other main electrode side via a capacitor, and an auxiliary electrode connected to either main electrode side,
It is characterized by having a trigger wire extending along the outer peripheral surface of the arc tube in the direction of both main electrodes.

Since the auxiliary electrode is placed close to the main electrode in a non-contact state, even at low starting voltages, the gap between the auxiliary electrode and the main electrode is very easy to dielectric, and the electric field is efficiently concentrated during starting, resulting in extremely strong electric field. Starts discharging in a short time. Subsequently, due to this discharge, an electric field is concentrated between the trigger wire and the trigger wire, and a discharge current begins to flow between the trigger wire and the main electrode. When this discharge current becomes a trigger and glow discharge begins at both main electrodes, and the discharge resistance between the two main electrodes decreases, the auxiliary electrode is connected to the other main electrode via the capacitor. Therefore, the discharge between the auxiliary electrode and the main electrode stops, and arc discharge starts between the two main electrodes, causing lighting. In other words, even at a low starting voltage, arc discharge begins between the two main electrodes and the lamp lights up in an extremely short period of time.

〔Example〕

The present invention will be specifically described below based on embodiments shown in the drawings.

The drawing shows a rare gas fluorescent lamp with a rated power consumption of 5W and an example of its wiring, which is used in a facsimile for _A4 size paper. In the drawing, the arc tube 1 is made of soft glass and has a length of 245 mm and an inner diameter of 5 mm, and its inner wall surface is coated with a phosphor 11, which is shown by dotted lines for convenience. In the arc tube 1, a rare gas such as xenon gas is sealed at a gas pressure of 100 Torr, and mercury vapor is not sealed. Glass stems 2 are welded to both ends of the arc tube 1. This glass stem 2 has a lead wire 3 made of nickel wire or Kovar wire.
a and 3b are planted, and main electrodes 4a and 4b are attached to their tips, respectively, and are arranged facing each other. Here, the distance between the main electrodes 4a and 4b, ie, the discharge path length, is 225 mm. The main electrodes 4a and 4b are
For example, a sintered body of tungsten powder is impregnated with an oxide of an alkali metal or alkaline earth metal as an electron emitter, or a coil coated with an electron emitter is placed inside a metal pipe. However, in any case, it is a so-called cold cathode type that does not require preheating, and starts up quickly after startup. The filament type, which requires preheating, has a slow rise time.
Undesirable. The lead wire 3a is connected to one end of the secondary side of the transformer T via a current limiting capacitor _C1 , and the lead wire 3b is connected to the other end of the secondary side. Next, an auxiliary electrode 5 is arranged in a non-contact manner near one main electrode 4a, and is connected to a lead wire 3b to which the other main electrode 4b is attached via a capacitor _C2 . This auxiliary electrode 5 may also be provided on the other main electrode 4b.
Further, a trigger wire 6 is provided in the axial direction of the outer circumference of the arc tube 1.
is arranged and extends toward both main electrodes 4a, 4b, and this trigger wire 6 is electrically connected to one of the secondary sides of the transformer T.

When a starting voltage of about 2 to 3 kV is applied to such a rare gas fluorescent lamp, first, an electric field is efficiently concentrated between the main electrode 4a and the auxiliary electrode 5, which are arranged close to each other, and a discharge occurs between them. Induced by this discharge, a discharge occurs between the trigger wire 6 and the main electrode 4a, and subsequently between the trigger wire 6 and the main electrode 4b.
That is, the trigger wire 6 functions quickly and the main electrode 4
A breakdown occurs between a and 4b, and a glow discharge occurs. As a result, the discharge resistance between the main electrodes 4a and 4b decreases, and a steady state is reached and the lighting starts. However, when the discharge resistance between the main electrodes 4a and 4b decreases, the auxiliary electrode 5 connects the capacitor _C2. Since the other main electrode 4b is connected to the attached lead wire 3b through the main electrode 4b, the discharge between the main electrode 4a and the auxiliary electrode 5 is almost stopped. That is, during lighting, discharge occurs mainly between the main electrodes 4a and 4b.

In this way, at the time of starting, the electric field is efficiently concentrated between the main electrode 4a and the auxiliary electrode 5, and the function of the trigger wire 6 is added to this, so even at a low starting voltage, the lighting performance is extremely good. The lamp reaches its steady state in an extremely short period of time, and reaches its full potential within 100 msec after starting. Therefore, it is suitable as a light source lamp for a facsimile machine used in a dark atmosphere.

[Effect of idea]

As explained above, in the rare gas fluorescent lamp of the present invention, in addition to the trigger wire on the outer periphery of the arc tube, the auxiliary electrode is placed close to the main electrode in a non-contact manner. A rare gas fluorescent lamp that lights up in a steady state and has excellent start-up properties can be obtained.

[Brief explanation of the drawing]

The drawing is a sectional view of an embodiment of the present invention. 1... Arc tube, 2... Glass stem, 3a, 3
b... Lead wire, 4a, 4b... Main electrode, 5...
Auxiliary electrode, 6...Trigger wire, _C1 , _C2 ...Capacitor.

Claims (1)

[Scope of utility model registration request] A pair of main electrodes are placed opposite each other at both ends of an arc tube filled with rare gas, and an auxiliary electrode is placed close to one main electrode in a non-contact state and connected to the other main electrode via a capacitor. , and a trigger wire connected to one of the main electrodes and extending along the outer peripheral surface of the arc tube in the direction of both main electrodes.