JPS6349853B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp, and more particularly to an improvement in a discharge lamp in which the discharge light emitting region can be variably controlled along the longitudinal direction of the discharge lamp.

The discharge lamp disclosed in Patent Application No. 131801 filed in 1982 by the applicant of the present invention has a linear electrode locally formed within the tube of the discharge lamp. , the other electrode made of a transparent conductive thin film is formed on the outer surface of the tube over almost the entire area. According to a discharge lamp having such a structure, by sequentially increasing or decreasing the voltage level or frequency of the drive signal supplied between one internal electrode and the other external electrode, the discharge light emitting region, that is, the longitudinal direction of the discharge path tube can be adjusted. It can be variably controlled in the direction. This type of discharge lamp can give a dynamic effect to the upper content itself displayed by emitting discharge light, so it is extremely convenient for application to display means for advertisements, etc. .

By the way, when the discharge light emitting area is sequentially and variably controlled along the longitudinal direction of the tube using the discharge lamp having the above-described configuration, the brightness in the discharge light emitting area tends to gradually decrease as it moves away from the vicinity of one electrode in the tube. As a result, the brightness distribution of the information content is not uniform, resulting in color unevenness, etc.
Furthermore, according to the above-mentioned discharge lamp, the temperature rise at the tip of one of the internal electrodes is large, which causes blackening of the inner wall of the tube due to evaporation of one of the internal electrodes in a short period of time, which significantly shortens the life of the discharge lamp. There were flaws that made it shorter.

The present invention covers the periphery of the tip of the one internal electrode with a well-known getter material such as titanium, tantalum, or zirconium, which has excellent adsorption properties for harmful emissions such as harmful gases and impurities in the discharge lamp tube. , and the getter material is attached so as to protrude from the electrode in the longitudinal direction of the tube, and further, between the tip of the other external electrode and the tip of the getter material, on which a transparent conductive thin film is attached on the surface outside the discharge lamp tube. By setting the longitudinal gap dimension of the discharge lamp to a gap dimension that regulates the spread of ions emitted from the one internal electrode toward the other external electrode, the discharge path during discharge light emission is regulated, and the above-mentioned The aim is to alleviate the drawbacks of conventional discharge lamps as much as possible.

Furthermore, since the discharge lamp according to the present invention is constructed as described above, when the ions emitted from one of the internal electrodes pass through the inside of the getter material cylinder, they are multiplied by secondary emission and the luminance of the entire light emitting area is reduced. This type of discharge lamp is particularly effective when applied as a display means, as it is not only possible to make the discharge path significantly larger than that of conventional discharge lamps, but also to increase the length of the discharge path itself. There is.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In addition, in the following examples, the pipe diameter is 2 mm or more.
The case where a comparatively small discharge lamp with a tube diameter and tube length of about 10 mm and a tube length of about 20 mm to 200 mm is used will be explained, but the present invention can be applied in exactly the same way even if the tube diameter and tube length exceed this range. It can be applied to

In FIG. 1, a discharge tube 1 forming a discharge lamp P is formed of a soft glass material such as transparent soda glass or a hard glass material such as borosilicate glass in a linear shape as shown. An inert gas such as neon gas, krypton gas or xenon gas is sealed inside the discharge tube 1 under a pressure of several mmHg to several 100 mmHg. Inside the discharge tube 1, a linear internal electrode 2 serving as one of the internal electrodes of the discharge lamp P is locally provided at an end of the discharge tube 1, as shown. When the above-mentioned soft glass material is used for the discharge tube 1, it is preferable to use, for example, a dumb wire for the internal electrode 2, and
When a hard glass material is used for the discharge tube 1, it is preferable to use a tungsten wire for the internal electrode 2. At the tip of the internal electrode 2, a getter material 3 made of titanium, tantalum, zirconium, etc., which has particularly excellent adsorption properties for harmful emissions such as harmful gases and impurities, is attached so as to protrude from the internal electrode 2. Efforts are being made to extend the life of P.
The getter material 3 has a hollow cylindrical shape, for example, as shown in FIG. is fixed to the tip of the internal electrode 2 by spot welding.

When the getter material 3 is attached to the internal electrode 2 as shown in FIG. 2, the periphery of the tip 2a of the internal electrode 2 will be surrounded by the getter material 3.
A discharge path between one internal electrode 2 and the other external electrode 4, which will be described later, is formed through the hollow part of the getter material 3.

Further, the other external electrode 4 is formed outside the discharge lamp P along the longitudinal direction of the discharge tube 1. The external electrode 4 is formed by spraying, for example, an aqueous solution of tin halide onto the surface of the discharge tube 1 heated to 500°C to 700°C, and depositing a transparent conductive thin film of tin oxide on the surface. It is formed by
The conductive wire 5 is for supplying power to the discharge lamp P and is connected to the external electrode 4. Furthermore, the gap size in the longitudinal direction of the discharge lamp P between the tip of the getter material 3 and the tip of the other external electrode 4 is a gap size d that regulates the spread of ions emitted from one internal electrode 2 toward the other external electrode 4. Set to .

3a to 3e show various shapes of the getter material 3 attached to the tip 2a of the internal electrode 2.
Figures 3 a and b show square and cylindrical getter materials, c is cylindrical, d is triangular and cylindrical, and e
A gator material 3 having an oval and cylindrical shape is shown.
In Fig. 3, b and c show an embodiment formed using a plate-shaped material, but it is also possible to form the getter material 3 in the shapes shown in a, d, and e using a plate-shaped material. is also possible.

FIG. 4 shows a specific electrical circuit diagram for discharging and emitting light from the discharge lamp P shown in FIG. A few V is applied to transistor 9 via
For example, it is used to supply low voltage DC power of about 3V to 12V. The control signal generator 7 supplies the transistor 9 with a signal of several hundred Hz, for example, 300Hz to 20K.
This is for supplying a control signal, such as a pulse signal having a frequency of Hz, which serves as a drive signal for the discharge lamp P.
The step-up transformer 8 is used to step up the control signal to the voltage level required to cause the discharge lamp P to discharge and emit light.
Generates a pulse signal of about 500V to 1200V.

FIG. 5 shows a drive signal, that is, control, for continuously variable control of the length of the discharge path, which is the light emitting area of the discharge lamp P, by sequentially increasing or decreasing the voltage level of the drive signal supplied to the discharge lamp P. A specific electrical circuit diagram of a control signal generating device 7 suitable for generating a signal is shown. In Figure 5,
The number of pulse signal generators 10 is several hundred as shown in FIG. 6a.
The sawtooth wave signal generator 11 is used to generate a pulse signal of about Hz to several kHz, and the sawtooth wave signal generator 11 is shown in FIG. 6b.
This is for generating a sawtooth wave signal of approximately a fraction of a Hz to several Hz as shown in FIG. The AND gate circuit 12 receives both the output signals of the pulse signal generator 10 and the sawtooth wave generator 11 as input signals, and generates an output signal as shown in FIG. 6c. Furthermore, the fifth
In the figure, input terminals 13 and 14 are power input terminals, which are connected to the power supply device 6 of FIG. 4, and an output terminal 15 is a control signal output terminal, which is connected to the transistor 9 of FIG. 4.

FIG. 7 shows a getter material 3 as described above attached to the tip of the internal electrode 2 so as to protrude from the internal electrode 2 in the longitudinal direction of the tube, and an external electrode 4 made of a transparent conductive thin film on the surface of the discharge tube 1. This figure shows the discharge light emitting situation of the discharge lamp P when a part of the end surface portion on the side of one internal electrode 2 is removed, and the discharge light emitting region is shown with diagonal lines. As shown in the figure, the external electrode 4 made of a transparent conductive thin film extends over almost the entire surface of the tube, excluding a portion of the tube surface up to a position a predetermined distance d from the tip of the getter material 3, which is the end of the internal electrode 2. It is formed with
According to experiments, the distance d varies depending on the pipe length, and is preferably about 2 mm to 10 mm.

FIG. 8 shows the luminance distribution of the light emitting region during discharge light emission of the discharge lamp P, where the horizontal axis represents the distance D of the light emitting region along the longitudinal direction of the tube, and the vertical axis represents the brightness L at the distance D. shows. In the figure, the solid line indicates the luminance distribution of the discharge lamp P according to the prior art, and the broken line indicates the luminance distribution of the discharge lamp P according to the present invention.

The discharge lamp P in this embodiment has the above configuration, and its operation will be explained next.

First, both the internal and external electrodes 2 and 4 of the discharge lamp P shown in FIG. 1 are connected to the step-up transformer 8 as shown in FIG.
The following describes the case where the secondary winding is connected to the secondary winding.
Now, in FIG. 4, when a control signal as shown in FIG. In between, a pulse signal whose peak level increases sequentially during period T1 is applied. As shown in Fig. 1, the discharge lamp P has a structure in which a gas filled with neon or the like and a dielectric glass material are interposed between the electrodes 2 and 4, so that the level of the applied voltage increases, that is, the intensity of the electric field increases. Accordingly, the light emitting area of the discharge lamp P increases continuously. That is, the length of the discharge path of the discharge lamp P is sequentially extended in the direction of the arrow from the right end to the left end of the paper of FIG. 1 every fixed period T1 according to the control signal, giving a dynamic change to the display content itself.

By the way, in the discharge lamp P according to the present invention, the getter material 3 is attached to one of the internal electrodes 2 so as to protrude in the longitudinal direction of the tube, as shown in FIG.
Since the getter material 3 is configured to surround the tip 2a of the internal electrode 2, the ions emitted from one internal electrode 2 toward the other external electrode 4 of the transparent conductive thin film are emitted from the getter material 3. Regulated by the inner cylinder. Therefore, the light emitting area of the discharge lamp P is restricted as shown by the shaded area in FIG.
In particular, according to the discharge lamp P of the present invention, the local heat generation effect of the electrode itself is reduced during discharge light emission, so the well-known blackening phenomenon that occurs on the tube wall is largely prevented, and the life of the discharge lamp P itself is extended. This is extremely convenient.

Further, according to the discharge lamp P of the present invention, the ion emission within the cylinder of the getter material 3 is significantly promoted by the multiplication effect, and the radiation direction is regulated due to the structure of the getter material 3. Since the other external electrode 4 of the magnetic thin film is formed excluding the end surface portion as shown in FIG. 7, the discharge path, that is, the light emitting area not only increases greatly under the same energizing energy but also causes uneven brightness. It can be made significantly smaller. Moreover, these functions and effects can be obtained by adjusting the outer shape of the getter material 3, for example, as shown in FIGS. 3a to 3e,
It can be arbitrarily changed by changing the tube radius, the length of the tube's protrusion in the longitudinal direction of the tube, the distance between the electrodes 2 and 4 in the longitudinal direction of the tube, etc., as shown by d in FIG.

As described above, the discharge lamp according to the present invention has a getter material attached to the tip of one of the internal electrodes, thereby preventing blackening, preventing uneven luminance in the discharge path, and significantly improving the discharge path itself. Since it can be increased, it is extremely effective in practice.

In addition, in the present invention, a case has been described in which a voltage that increases or decreases sequentially is applied between both the internal and external electrodes of the discharge lamp, but since both electrodes are capacitively coupled, Even if the frequency of the drive signal is increased or decreased, the discharge lamp operates in the same manner as described above.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of an embodiment of a discharge lamp to which the present invention is applied. FIG. 2 shows the main parts of FIG. 1 in an external view.
FIGS. 3a to 3e show external views of various shapes of getter materials applicable to the present invention. FIGS. 4 and 5 show specific electrical circuit diagrams for causing the discharge lamp to emit light by discharge in this embodiment. FIG. 6 shows an output waveform diagram showing details of the control signal which is the drive signal. 7th
FIG. 8 and FIG. 8 are explanatory diagrams showing the operating status of the discharge lamp applied to the present invention. DESCRIPTION OF SYMBOLS 1...Discharge tube, 2...Internal electrode, 2a...Tip part, 3...Getter material, 4...External electrode.

Claims (1)

[Claims] 1. One of the two electrodes is formed locally protruding from one end of the glass discharge lamp tube filled with an inert gas, while the other electrode is formed outside the discharge lamp tube. A transparent conductive thin film is attached to the entire surface of the discharge lamp except for the vicinity of the electrodes, and the voltage level or frequency of the drive signal supplied between these two electrodes is sequentially increased or decreased. In a discharge lamp configured to variably control a light emitting area, a cylindrical getter is provided at the tip of one electrode in the discharge lamp tube, surrounding the one electrode and protruding concentrically from the tip of the one electrode. At the same time, the gap size in the longitudinal direction of the discharge tube between the tip of the cylindrical getter and the transparent conductive thin film electrode is adjusted to restrict the spread of ions emitted from the one electrode toward the other electrode. A discharge lamp characterized by having dimensions (d) that allow the discharge area to be expanded.