JPS5832201Y2 - flash discharge tube - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a flash discharge tube used in a flash device such as a strobe.

Conventionally, this flash discharge tube has a glass tube with a circular cross section filled with gas such as xenon, electrodes (positive and negative electrodes) are provided at both ends, and a transparent conductive paint is applied to the glass tube wall to create a trigger electrode. was formed.

The lead wire for the trigger electrode was a thin wire wrapped around the part of the glass tube coated with transparent conductive paint, and fixed with conductive paint or the like.

By the way, when using this as a flashlight, it must be attached to a reflector.

The reflecting mirror is formed in a shape whose cross section is similar to a second-order or higher-order function curve other than a circle, and holes for the discharge tube are provided at the bottoms of both ends, and the discharge tube is attached to the holes.

As flash devices are required to be made smaller, discharge tubes and reflectors must also be made smaller.

When the reflector is made smaller, the discharge tube and the bottom of the reflector become closer together.

Since the reflector is usually molded from synthetic resin, it may deform when it approaches the discharge tube due to the heat of the discharge tube.

As described above, the reflecting mirror has a cross section shaped like a high-order function curve so as to uniformly radiate light from the discharge tube in a certain predetermined direction.

If this is deformed, the spread of light from the flasher will be distorted, which is not desirable.

Therefore, there is a certain limit to miniaturization, but the present invention was made to overcome this current situation, and is aimed at providing a discharge tube that is useful for miniaturizing flash devices. be.

Therefore, in the present invention, the shape of the discharge tube itself is made of glass that combines a reflector and a protector that covers the light emitting part, and a metal layer is provided on the outside of the part corresponding to the reflector. It is characterized by having a light reflecting surface.

That is, the discharge tube itself also serves as a reflecting mirror.

By doing this, it is possible to downsize the device, and in addition, the metal layer can be used as a trigger electrode, and it is also possible to directly weld the lead wire thereto.

The illustrated embodiment will be described below.

FIG. 1 is a cross-sectional view of a discharge tube according to an embodiment of the present invention, in which the main body portion 1 has a cross-sectional shape similar to a curve of a second or higher order function other than a circle, similar to a conventional reflecting mirror. The main body part 1
It has a shape formed by a lid part 2 that covers the open end of the holder.

Of course it's made of glass. There are various methods for manufacturing glass tubes with this shape, but here are some examples:
As shown in the figure, a mold 3 made of carbon having the same cross-sectional shape as the glass tube is placed inside a normal glass tube 4, and the glass tube 4 is heated while being heated from the outside of the glass tube 4.
By pulling out the glass tube, a glass tube having the cross-sectional shape of mold 3 can be obtained by heat shrinkage.

This may be cut to an appropriate length.

Naturally, it is also possible to perform heat molding using male and female molds, and it may also be made by separating the molded parts into two parts and joining them together.

In any case, a glass tube having the above-mentioned cross-sectional shape is cut into an appropriate length, both ends of which are sealed, and an anode 5 and a cathode 6 are attached thereto.

Conventional techniques can be used as is for sealing both ends, attaching each electrode, and filling the inside with gas.

However, one side, the end with the cathode 6 in Fig. 4, can be simply sealed in the same way as before, but the other end, that is, the end that will be sealed later, has a wide glass tube end, so if it is left as is, it will not be possible to exhaust gas. injection is difficult.

Therefore, as shown in Fig. 4, a thin tube 7 with one end widened to match the shape of the end of the glass tube is attached in advance to the end, and an electrode attached to a bead is placed inside this thin tube T. Similarly, after exhausting and injecting gas, it is fused and sealed.

In this way, a discharge tube whose cross section is shown in FIG. 1 is produced.

Further, a metal layer 8 is formed on the outer surface and both ends of the main body 1 of the discharge tube.

This metal layer 8 serves to make the main body portion 1 and both ends a light reflecting surface, and also serves as a trigger electrode.

Therefore, it is necessary to avoid getting it around the positive and negative electrodes.

Similarly, the lid part 2 is not provided at all.

The easiest way to form this metal layer 8 is by metal vapor deposition.

Alternatively, silver paint may be applied or metal baking may be used.

In the manner described above, the discharge tube according to the present invention can be manufactured.

As with the conventional discharge tube, a high voltage is applied between the positive and negative electrodes, and when a high voltage pulse is applied to the metal layer 8 which becomes the trigger electrode, the internal gas is ionized, and the rear corner and negative electrodes are ionized. A discharge occurs in between.

The light generated by this discharge is reflected by the metal layer 8 and is emitted from the lid 2 with a spread determined by the shape of the main body 1.

Therefore, according to the present invention, it can be directly attached to a flash device without using a reflecting mirror as in the conventional case, and it can be useful for downsizing the flash device.

When the discharge tube itself is further downsized and light diffusion is not sufficient, a projection 9 is provided at the tip of the main body 1 and a light diffusing plate 10 is attached to the tip of the projection 9, as shown in FIG. is desirable.

The light diffusing plate 10 does not need to be made of glass, but may be made of transparent plastic such as acrylic and has appropriate irregularities on its surface to diffuse light.

[Brief explanation of drawings]

Fig. 1: A sectional view of the knee embodiment, Fig. 2: Its perspective view, Fig. 3:
Figures: Diagrams showing the manufacturing state of the glass tube according to the present invention, Figure 4: A side view of the embodiment in the middle of manufacture, Figure 5: A side view of another embodiment. DESCRIPTION OF SYMBOLS 1...Main part, 2...Lid part, 5...Positive electrode, 6...
...Cathode electrode, 8...Metal layer.

Claims (1)

[Scope of utility model registration request] A glass tube comprising a main body whose cross-sectional shape approximates a quadratic or higher-order function curve other than a circle, and a lid that covers an open part of the main body, and seals both ends of the glass tube. 1. A flash discharge tube characterized in that a positive electrode and a negative electrode are provided at both stopped end portions, a metal layer is formed at least on the outside of the main body portion of the glass tube, and the metal layer is used as a trigger electrode.