JPS5994358A - Flash discharge tube - Google Patents

Abstract

PURPOSE:To prevent increase of starting voltage or breaking of firing circuit even for continuous flashing, by fixing at least one end of trigger wire to a metal ring through a thermal responsive member operating to pull the trigger wire. CONSTITUTION:Metal rings 5, 6 are fixed on the outer face at opposite ends of a glass tube 1 provided with an anode 2 and cathode 3 at the opposite ends while a trigger wire 4 is provided along the axis of tube while contacting tightly against the outer face of said tube 1, where one end of trigger wire 4 is fixed to one metal ring 5 while the other end is fixed through a U-shaped thermal responsive member 8 to the other metal body 6. Consequently even if the trigger wire 4 has thermally expanded due to continuous flashing, the thermal responsive member 8 for pulling the trigger wire 4 through heat from the glass tube 1 and radiated light coupled to the other end of trigger tube 4 will deform as shown by dashed line to prevent loosening thus to maintain such state as contacting tightly against the outer face of glass tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flash discharge tube used as a flash fixing light source for facsimiles, an exposure light source for various copying machines, a strobe light source for photography, and the like.

Conventional structure and problems Generally, a flash discharge tube is constructed by storing charge in a capacitor and applying a high-frequency trigger voltage to a trigger wire attached to the outer surface of the glass tube. The electric charge is instantly discharged between the anode and cathode to generate a flash of light. When the charge in the capacitor is consumed by the flash discharge, the capacitor is charged again. The flash discharge tube can repeatedly produce flashes in synchronization with the period of application of the trigger voltage to the trigger wire.

First, to explain a conventional flash discharge tube with reference to FIG. 1, an anode 2 and a cathode 3 are provided at both ends of a glass tube 10 such as a quartz glass tube. Gas is sealed.

A metal ring 6°6 is fixed on the outer surface of the glass tube 1 near both electrodes. The trigger wire 4 is attached closely to the outer surface of the glass tube 1, and its both ends (are attached to metal rings 5 and 6), and the middle portion is wrapped around the glass tube 1. Note that 7 is a lead wire.

When a flash discharge tube with such a conventional structure is used for continuous flashing, the trigger wire 4, which was in close contact with the outer surface of the glass tube 1 at room temperature, becomes loose as shown by the dashed line due to thermal expansion, and the glass tube 1 becomes loose due to thermal expansion. loss of contact with the outer surface. Such loosening of the trigger wire causes an increase in the starting voltage of the flash discharge tube, causing the flash discharge tube to sometimes fail to start or not to start at all. In addition, a part of the loose trigger wire may come into contact with the support or reflector of the flash tube, and the trigger voltage may leak from this contact, making it impossible to start or destroying the lighting circuit. Ta.

In order to eliminate this problem, it has been proposed to attach a spring member to the end of the trigger wire, but even with this structure, the elastic force of the spring member is weakened by the heat of the glass tube. However, the disadvantage was that the intended purpose was not completely achieved.

OBJECT OF THE INVENTION The present invention has been made to eliminate these conventional drawbacks, and even when used with continuous flashing, the trigger wire does not become loose, thereby preventing an increase in the starting voltage or a drop in the trigger voltage. An object of the present invention is to provide a flash discharge tube that can prevent a lighting circuit from being destroyed by.

Structure of the Invention The present invention is characterized in that a metal ring is fixed to the outer surface of both ends of a glass tube having an anode and a cathode at both ends, a trigger wire is attached so as to be in close contact with the outer surface of the glass tube, and at least one end of the trigger wire is It is attached to a metal ring via a thermally responsive body that operates to pull the trigger wire, and the thermally responsive body is operated to pull the trigger wire,
The trigger wire is always kept in close contact with the outer surface of the glass tube.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a flash discharge tube which is an embodiment of the present invention, in which metal rings 5 and 6 are fixed to the outer surface of both ends of a glass tube 1 having an anode 2 and a cathode 3 provided at both ends. glass tube 1
A trigger wire 4 is attached along the tube axis direction so as to be in close contact with the outer surface of the tube. One end of the trigger wire 4 is attached to one metal ring 6, and the other end is attached to the other metal body 6 via a U-shaped thermally responsive body 8.

According to such a configuration, even if the trigger wire 4 thermally expands during continuous flash use, the glass tube 1 is attached to the other end of the trigger wire 4.
Since a thermally responsive body 8 is connected which pulls the trigger wire 4 using the heat of the heat and the heat of the radiant light, the thermally responsive body 8 deforms as shown by the dashed line, and the trigger wire 4 is thereby stretched. , it is possible to maintain a state in close contact with the outer surface of the glass tube 1 without causing loosening.

FIG. 3 shows another embodiment of the invention, in which a trigger wire 4 is spirally wound around a glass tube 1, and one end of the trigger wire 4 is attached to one metal ring. , the other end is attached to the other metal ring 6 via a linear heat-responsive body 8 whose tip expands outward due to the heat of the glass tube 1 and the heat of the radiation light. be.

Also in this embodiment, when using continuous flash, the trigger wire 4
Even when the trigger wire 4 thermally expands, the thermally responsive body 8 deforms as shown by the dashed line, so the trigger wire 4 is not pulled and loosened, and therefore the same effect as described above can be obtained.

Next, a specific example of the present invention will be explained.

Xenon gas was placed in a quartz glass tube with an emission length of 2907 m and an outer diameter of 11 mm at a pressure of 600 rran Hq/2.
A trigger wire made of a nickel wire with a wire diameter of 0.3 rmn was used, and a heat-responsive body made of a bimetallic plate with a thickness of 0.3 mm and a width of 1.5 mm was used. 3. Fabricate flash discharge tubes with the structure shown in Figure 3, and charge them with a capacitor charging voltage of 280o and a trigger voltage of 12 to 18.
Flash '3E-D 500 Zeal with flash interval of 1 second and 1
．． It worked in 5 seconds. As a result, the glass tube tube V temperature during these 3000 consecutive flashes was 280 to 360C. And even in more than 10,000 consecutive flashes,
The trigger wire did not loosen, and the flash discharge tube never stopped flashing. Furthermore, it was confirmed that even after 400,000 continuous flashes, there was no increase in the starting voltage due to loosening of the trigger wire.
4. In the above embodiment, an example was explained in which the thermally responsive body was connected only to one end of the trigger wire, but it may be connected to both ends of the trigger wire, and this structure can be used when a long glass tube is used. This is particularly effective.

As described in the detailed description of the invention↓, the present invention includes an anode and a cathode at both ends of a glass tube, a metal ring fixed to the outer surface of both ends of the glass tube, and a trigger so as to be in close contact with the outer surface of the glass tube. Since at least one end of the trigger wire is attached to the metal ring via a thermally responsive body that operates to pull the trigger wire, the trigger wire will not loosen even during continuous flashing. Therefore, it is possible to provide an extremely reliable flash discharge tube without causing difficulty in starting, and also solving the problem of destruction of the lighting circuit due to trigger voltage leakage. It is.

[Brief explanation of drawings]

FIG. 1 is a front view of a conventional flash discharge tube, FIG. 2 is a front view of a flash discharge tube which is an embodiment of the present invention, and FIG. 3 is a front view of a flash discharge tube which is another embodiment of the present invention. It is a diagram. 1...Glass tube, 2...@pole, 3...
...Cathode, 4...Trigger wire, 5,6...
...Metal ring.

Claims (1)

[Claims] An anode and a cathode are provided at both ends of the glass tube, a metal ring is fixed to the outer surface of both ends of the glass tube, a trigger wire is attached so as to be in close contact with the outer surface of the glass tube, and at least one end of the trigger wire is attached. . A flash discharge tube, wherein the flash discharge tube is attached to the metal ring via a thermally responsive body that operates to pull the trigger wire.