JPH0522335B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a display discharge lamp that utilizes discharge light emission between electrodes and is suitably used as a light source for various displays. According to
The present invention relates to display discharge lamps that achieve high brightness and can be lit using various driving methods.

[Prior Art] Conventionally, small incandescent light bulbs, various discharge lamps, or luminescent lamps have been used as light sources for various displays such as traffic information displays on expressways, destination and time displays at airport terminals, and general advertising displays outdoors. Diodes etc. are widely used. The present applicant has also proposed a display discharge lamp incorporating a hollow cathode as the above-mentioned display light source (Japanese Patent Laid-Open No. 59-20960).

The display discharge lamp 1 has, as shown in FIG.
A conical cathode 2 and an anode 2' are opposed to each other with a discharge gap in between, and are housed in an airtight container 4 made of a glass bulb to seal in a discharge gas, and are connected to the cathode 2 and anode 2', respectively. lead wire 3,
3' is led out of the container 4.

The display discharge lamp described above has a hollow cathode effect by setting the operating position of the cathode on the inner surface of the conical cathode, and generates high-intensity discharge light over a wide area covering the entire inner surface of the cathode. In this case, the shape and position of the anode 2' are not particularly limited, and in addition to the rod-shaped anode 2' arranged inside the cathode 2 as shown in FIG. , a conical anode 2' is disposed outside the cathode 2, and a ring-shaped anode 2' is disposed opposite the front surface of the opening of the cathode 2, as shown in FIG. 5B.

[Problems to be Solved by the Invention] However, since the display discharge lamp described above incorporates a conical cathode in order to obtain a hollow cathode effect, the display performance is significantly impaired when pulse drive or AC drive is performed, so that the display discharge lamp is not adopted. The possible driving methods are substantially limited to DC driving.

In other words, since the discharge area of the cathode is wide and covers the entire inside of the cone, it takes time to reach full discharge after voltage is applied.If voltage is applied for a short time by pulse drive, the full discharge time is extremely short. Summer,
Depending on the pulse width, a full-scale discharge may not occur. Moreover, since the discharge starting point on the cathode is not constant, the light emitting point due to partial discharge appears to move here and there on the cathode, resulting in a dark and flickering display. Furthermore, in the case of pulse driving, in order to obtain luminance equivalent to that of direct current driving, the voltage and current values need to be higher than those of direct current driving. As a result, the open end of the conical cathode, where the electric field is concentrated, sputters, and the spatter material adheres to the inner wall of the airtight container, causing blackening and reducing light transmittance.

In addition, when AC driving is performed, the cathode and anode are replaced every cycle of the applied voltage, and the shapes and dimensions of the two electrodes are different.
The light emitting area and light emission brightness vary depending on the electrode that generates the discharge, resulting in non-uniform light emission.

The present invention was devised in view of the above points, and
The object of the present invention is to realize a display discharge lamp that can be lit by alternating current driving and pulse driving other than direct current driving without impairing display performance, and can fully exhibit the characteristics of each driving method.

[Means for Solving the Problems] In order to achieve the above object, as a result of various studies, the present invention was completed by enclosing a plurality of pairs of discharge electrodes having the same discharge characteristics.

Therefore, the display discharge lamp of the present invention has a first discharge electrode and a second discharge electrode formed in a rod shape or a spherical shape having substantially the same shape and size and facing each other with a predetermined discharge gap in between. A display discharge lamp is formed by encapsulating a plurality of pairs of discharging electrodes arranged and formed in an airtight container together with a predetermined discharge gas, and the airtight container includes a display portion formed by processing a lens, and a display portion formed by processing a lens. and a light reflecting layer formed on the inner or outer surface or both of the surfaces excluding the display section, and the first discharge electrodes are integrally connected to an external drive circuit by a common connection, and the second discharge electrode is integrally connected to an external drive circuit by a common connection. The discharge electrodes are also integrally connected to an external drive circuit through a common connection, and discharge light emission generated simultaneously in a plurality of discharge gaps by voltage application from the external drive circuit is
The display device is characterized in that the pair of discharge electrodes are arranged so as to be located at or within the focal length of the lens of the display section.

[Operation] As described above, in the present invention, since the first discharge electrode and the second discharge electrode constituting the pair of discharge electrodes are rod-shaped or spherical with substantially the same shape and the same dimensions, both discharge electrodes The discharge characteristics of the two are approximately the same. Therefore, since there is no difference in the light emitting area or light emission brightness due to the discharging electrodes, uniform light emission can be obtained even if the light is turned on in a traffic driving method in which the cathode and the anode are replaced every cycle. In addition, since the area of each electrode is not very large, a sufficient overall discharge can be generated even with short-term voltage application, and the electric field distribution on the electrode surface is not extremely biased, so it is possible to apply a fairly high voltage. Even if you do, there is no risk of parts sputtering. Therefore, even if the voltage is applied for a short time and is lit using a pulse drive method in which a high voltage is applied, flickering or reduction in brightness does not occur.
It goes without saying that there is no problem in adopting the DC drive method.

Further, discharge light emission occurs simultaneously in a plurality of discharge gaps, and each discharge light emission is superimposed, so that high brightness can be obtained.

Furthermore, by forming a light-reflecting layer on the airtight container except for the display part, and arranging a pair of discharge electrodes so that the discharge light is located at or within the focal length of the lens of the display part, the airtight container is airtight. Since the discharge light generated within the container is intensively radiated to the outside from the display section, even higher brightness can be achieved.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIGS. 1 and 2 show a display discharge lamp according to an embodiment of the present invention, and are a longitudinal sectional view and a transverse sectional view, respectively.

In the figure, a display discharge lamp 1 is made by processing a metal material such as Ni or Al into a rod shape, and coating the surface with an oxide of an alkaline earth metal element (MgO, etc.).
SrO, etc.), composite metal oxides with aluminum (BaAl ₂ O ₃ , etc.), or oxides of rare earth elements (Y ₂
The first discharge electrode 2 and the second discharge electrode 2' are formed by depositing an emitter material 2a, 2a' such as O ₃ , La ₂ O ₃ , etc.) or boride (GdB ₄ , LaB ₆ etc.). Lead wires 3, 3' made of a composite wire, a 42-6 alloy wire, or the like are connected to one end of each of the lead wires 3 and 3', which are opposed to each other in substantially parallel manner with a discharge gap in between. The first discharge electrode 2 and the second discharge electrode 2' have substantially the same shape,
are formed to have the same dimensions.

This first discharge electrode 2 and second discharge electrode 2'
Prepare eight pairs of discharge electrodes formed by
These are placed in an airtight container 4 made of a glass bulb, and the lead wires 3, 3' are led out of the container 4, and the inside of the container 4 is evacuated through an exhaust pipe 4b to remove rare materials such as He, Ne, and Ar. It is filled with a discharge gas mainly composed of gas.

The inside of the airtight container 4 has a display section 4a at its top and is processed with a lens, and discharge is caused by applying a voltage between the first discharge electrode 2 and the second discharge electrode 2'. The discharge light generated in the gap is set to be located at or within the focal length of the lens. Therefore, the light from the display discharge lamp 1 is intensively radiated outward from the display section 4a in parallel or at a predetermined solid angle. Further, the airtight container 4 has a light reflecting layer 5 formed on its inner wall side circumferential surface and outer wall bottom surface,
The amount of light emitted from the display section 4a is increased. Furthermore, the airtight container 4 has a display section 4.
A light scattering layer 6 is formed on the inner surface of a to improve the uniformity of the display when viewed from close up.

In addition to the above-mentioned rod shape, the first discharge electrode 2 and the second discharge electrode 2' can also be suitably used in a spherical shape, since the electric field distribution on the electrode surface is not extremely biased. In addition, the first discharge electrode 2 and the second
The number of pairs of discharge electrodes formed by the discharge electrodes 2' to be sealed in the airtight container 4 may be appropriately set depending on the size of the display discharge lamp 1, desired brightness, etc.

In order to drive the display discharge lamp 1 with alternating current, the first discharge electrodes 2 are commonly connected through a stabilizing resistor R and integrally connected to an alternating current power source EA, as shown in FIG. 3A. At the same time, the second discharge electrodes 2' may be commonly connected via a stabilizing resistor R', integrally connected to the AC power source EA, and a voltage may be applied from the AC power source EA. As a result, the first discharge electrode 2 and the second discharge electrode 2' alternately discharge and emit light, and uniform light is emitted from the display section 4a.

In addition, as shown in FIG. 3B, the first discharge electrode 2 on the negative side is commonly connected via a stabilizing resistor R, and is integrally connected to the DC power supply ED, and the second discharge electrode 2 on the positive side ' are commonly connected and integrally connected to a DC power source ED, and a voltage is applied from the DC power source ED, thereby making it possible to drive the display discharge lamp 1 with DC current. In this case, if a gate element G is connected between the stabilizing resistor R and the DC power source ED, the first discharge electrode 2 to be discharged can be selected by opening and closing the gate element G, and the pair of light emitting By adjusting the number of discharge electrodes, the brightness of the display discharge lamp 1 can be modulated.

Furthermore, when the display discharge lamp 1 is pulse-driven, as shown in FIG. 3C, the first
The discharge electrodes 2 are commonly connected to each other via a stabilizing resistor R, and integrally connected to a pulse power source EP,
The second discharge electrodes 2' on the positive electrode side may be connected in common and integrally connected to the pulse power source EP, and a voltage may be applied from the pulse power source EP. According to this driving method, a large number of display discharge lamps 1 can be arranged in a matrix in the vertical and horizontal directions, and dynamic driving can be performed in which voltage is applied time-divisionally to each row or column, so the number of driving elements can be reduced to a large extent. A large display device can be constructed without the need for

[Effects of the Invention] As detailed above, the display discharge lamp of the present invention has the following features:
The first discharge electrode and the second discharge electrode that make up the pair of discharge electrodes are rod-shaped or spherical with approximately the same shape and dimensions, so they can be lit not only by DC drive but also by AC drive or pulse drive. , a good display with high brightness and no unevenness or flickering can be obtained.
Therefore, any of the above driving methods can be employed depending on the purpose, and the characteristics of each driving method can be fully exhibited.

In addition, in addition to enclosing multiple pairs of discharge electrodes,
By integrally driving and controlling the first discharge electrodes and the second discharge electrodes, discharge light emission can be generated simultaneously in a plurality of discharge gaps. Therefore, each discharge light emission is superimposed, and high brightness can be obtained.

In addition, a light-reflecting layer was formed on the airtight container except for the display area, and a pair of discharge electrodes were placed so that the discharge light was located at or within the focal length of the display lens. The discharge light emission is intensively radiated to the outside from the display section. As a result, even higher brightness can be achieved.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, and FIGS. 3A, B, and C are circuit diagrams for AC, DC, and pulse drive systems, respectively. , FIG. 4 is a side view of the conventional example, and FIG. 5 is a perspective view showing an example of the shape and arrangement of discharge electrodes in the conventional example. DESCRIPTION OF SYMBOLS 1... Display discharge lamp, 2... First discharge electrode, 2'... Second discharge electrode, 2a, 2a'... Emitter material, 4... Airtight container, 4a... Display unit,
5... Light reflecting layer, 6... Light scattering layer.

Claims (1)

[Scope of Claims] 1. A first discharge electrode and a second discharge electrode, which are formed into a rod shape or a spherical shape and have substantially the same shape and the same dimensions, are arranged facing each other with a predetermined discharge gap between them. An indicator discharge lamp comprising a plurality of pairs of discharge electrodes sealed together with a predetermined discharge gas in an airtight container, the airtight container having a display section formed by processing a lens, and an inner surface excluding the display section. or a light reflecting layer formed on the outer surface or both sides, the first discharge electrodes are integrally connected to an external drive circuit by a common connection, and the second discharge electrodes are also common to each other. It is integrally connected to an external drive circuit by a connection, and the discharge light generated simultaneously in a plurality of discharge gaps by voltage application from the external drive circuit is located at or within the focal length of the lens of the display unit. A display discharge lamp characterized in that the pairs of discharge electrodes described above are arranged respectively. 2. The display discharge lamp according to claim 1, wherein an emitter material is deposited on the surfaces of the first discharge electrode and the second discharge electrode. 3. The display discharge lamp according to claim 1 or 2, characterized in that a light scattering layer is formed on the inner surface of the display portion of the airtight container.