JPS63279556A - Low voltage discharge lamp - Google Patents

Abstract

PURPOSE:To make a start possible easily at a comparatively low lighting voltage by confining plasma in the vicinity of the discharge surface with a structure which encircles a part of the front surface of a blocking body and communicates with a discharge space. The blocking body is formed by blocking an end surface of a glass bulb and the inner surface is made to form a discharge surface. CONSTITUTION:An encircling body 4 which encircles the front surface of a couple of blocking bodies 3, 3 which block the inner end surface of the bulb 11 is provided and discharging apertures 42, 42... which have communicating parts with the encircling part 41 are arranged lengthwise in a file. When a lighting voltage is applied, a small discharge is generated in the neighborhood of a discharge surface 34 and the plasma in the discharge is confined between the discharge surface 34 and the encircling part 41 and becomes high density to emit electrons and ions. The emitted electrons and ions impinge against the metal surface of the discharge surface 34 and a large quantity of electrons are emitted; then the discharge in the neighborhood of the discharge surface 34 rapidly grows large. The electrons and ions emitted by the discharge are injected into the discharge space through the discharging apertures 42, 42... of the encircling body 4. Therefore, electrons are easily emitted; cathode voltage drop is small and a lamp can be started by a low lighting voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in a low-pressure discharge lamp in which substantially the entire length of a glass bulb is used as a discharge space and the light emitting length is increased relative to the bulb length.

(Prior Art) Currently, in transmissive liquid crystal display devices, there is a demand for lamps that are flat and have a large light emitting area despite their small size for back illumination of liquid crystal display elements.

In response to this demand, the inventor of the present invention has previously developed a low-pressure discharge lamp in which the end face of a glass bulb is closed with a closure whose main part is made of metal, the inner surface of which is formed into a discharge surface, and discharge gas is sealed. The patent application was filed as Japanese Patent Application No. 181921/1981.

In this low-pressure discharge lamp, the inner surface of the closing body forms the discharge surface, so almost the entire length of the bulb is used as a discharge space, and the light emission length can be increased relative to the length of the bulb.Furthermore, even if the bulb is made flat, it can be almost uniformly emitted. It has the advantage of being able to emit light and can be used as a surface light source.

(Problems to be Solved by the Invention) Since the discharge surface of this low-pressure discharge lamp forms a cold cathode, a high voltage or high frequency power source is required for discharge.

[Structure of the invention]

(Means for Solving the Problems) The present invention was made to facilitate the discharge of a low-pressure discharge lamp, which has a long luminous length relative to the bulb length. By providing an enclosure that surrounds a part of the front surface of the closure body with a surface and communicates with the discharge space to confine the plasma near the discharge surface, a discharge is generated using electrons and ions emitted from the confined plasma. It hits a surface and knocks out electrons.

(Function) Electrons and ions are emitted from plasma, and when these electrons and ions collide with a metal surface, the metal atoms are excited and become easier to emit electrons.The present invention applies this principle.
A part of the discharge surface was surrounded by an enclosure to confine the plasma and eject electrons, and at the same time, discharge was caused to occur from the communication portion to the discharge space.

(Example) The details of the present invention will be explained by referring to each illustrated example. 1st
4 through 4 show an example of a hollow cathode fluorescent lamp to which the present invention is applied. In the figure, (11) is a flat glass bulb with both ends open, and (2) is this bulb (11).
), (3), (3) are a pair of closing bodies that close both end faces of the bulb (11), and (4) are the two closing bodies (3), (3). It is an enclosure that surrounds the front side, one of which is shown in the figure, and (5) and (5) are power supply lines connected to the closure bodies (3) and (3). A discharge gas such as argon or mercury is then sealed inside the bulb (11).

As shown enlarged in FIGS. 1 and 2, the closure body (3) is attached to the opening edge of a metal bottomed shallow cylindrical body (31) that has a shape corresponding to the end face of the valve (11). (11)
A mounting collar (32) that fits on the outer surface is integrally formed, and the mounting collar (32) is hermetically sealed to the opening edge of the bulb (11) using glass solder (33), and the mounting collar (32) is hermetically sealed to the opening edge of the bulb (11). Braze the power supply lines (5) and (5). This - result,
The inner surface of the closure body (3) constitutes a discharge surface (34).

The surrounding body (4) is formed by bending a metal plate into a U-shape, and the surrounding part (41) has a shape and size that fits loosely into the inner surface of the end of the bulb (11), forming a communication part. A row of discharge holes (42), (42)... with a diameter of 3 to 5 cm are arranged along the longitudinal direction at intervals of approximately 3 to 5 cm, and both legs (43
), (43) are attached to the inner surface of the closure body (5) by means such as welding or brazing.

Next, the ratings, materials and dimensions of each component of the low-pressure discharge lamp of this embodiment are shown below.

Rated lamp voltage 105■ Lamp current 68a+A Lamp power 7v Lighting frequency 40KHz Bulb (1-1) 12120mm+1
70+s+w t 13mm Closure body (3) Stainless steel enclosure body (4
) Stainless steel discharge hole (42) diameter
42 mm Discharge gas Argon 2 Torr Next, the operation of the low pressure discharge lamp of this embodiment will be explained. The power supply lines (5), (5) are connected to a power source (not shown), and a lighting voltage of a predetermined frequency is applied. Then, a minute discharge is generated on the inner surface of the closing body (3), that is, near the discharge surface (34), and the plasma of this discharge is trapped between the discharge surface (34) and the surrounding part (41), becomes highly dense, and generates electrons. and ions. These emitted electrons and ions impact the metal surface of the discharge surface (34) and emit a large amount of electrons.
4) Nearby discharge increases rapidly. Then, electrons and ions emitted by this discharge enter the discharge hole (42) of the enclosure (4).

(42)... is emitted into the discharge space, where a positive column main discharge is generated and ultraviolet rays are emitted, and the ultraviolet rays stimulate the fluorescent film (2) to emit light.

In this way, near the discharge surface (34), plasma is trapped between the discharge surface (34) and the enclosure (4),
Since the discharge surface (34) is excited by impact, the discharge surface (34)
) is a metal surface, it has the advantage of being able to easily emit electrons, having a small cathode voltage drop, being easy to start even at a relatively low lighting voltage, and having low power consumption. By the way, according to the experiment, the electrode loss of this example was about 30
As is clear from the drawings and the above description, in the low-pressure discharge lamp of this embodiment.

Since light is emitted with a discharge space formed between the enclosures (4) provided at both ends of the bulb (1), the light can be emitted over almost the entire length of the bulb (1).
3), Since (3) has a shallow shape, its height is also relatively small, and therefore, this lamp has the advantage of a significantly longer light emitting length compared to the overall length.

Furthermore, in this embodiment, even if the sputtered material scatters from the discharge surface (34), it is blocked by the enclosure (4), so there is an advantage that blackening of the tube wall is significantly reduced.

Next, a second embodiment is shown in FIGS. 5 and 6, in which both ends of a flat glass bulb (11) similar to that of the first embodiment described above are connected to similar metal closing bodies (3). ), (
An enclosure (4) made of a ceramic plate having a shape and dimensions that closes the end face of the valve (11).
the end face of the valve (11) and the mounting collar (3) of the closure body (3).
32) and hermetically sealed with a glass solder (33), and the enclosure (4) has a row of discharge holes (42), (42)... with a diameter of 3 to 5 square meters. The same applies to the arrangement. Other identical parts are given the same reference numerals and explanations will be omitted.

Also in this second embodiment, the discharge surface (
34) is surrounded by the enclosure (4), the plasma caused by the micro discharge is confined, and the electrons and ions emitted from this plasma impact the discharge surface (34) and knock out electrons, causing more Since a large plasma is formed and the generated electrons and ions are ejected from the discharge hole (42) into the discharge space to generate a main discharge, it can be easily lit with a relatively low lighting lamp and power consumption can be saved.

Next, a third embodiment is shown in FIGS. 7 and 8, which includes two cylindrical glass bulbs (12).

(12) are arranged in parallel, and the end faces of both valves (12) and (12) are bridged to form a common enclosure (4) made of one metal plate.
and the outside of this enclosure (4) is surrounded by a common metal bottomed elongated cylindrical closure (3).
4) is due to the fact that two circular discharge holes (42), (42) with a diameter of approximately 5 m are drilled coaxially with the bulbs (12), (12).

It surrounds the discharge surface (34) of the closure (3). Other identical parts are given the same reference numerals and explanations will be omitted.

Also in this third embodiment, the discharge surface (
34) and the enclosure (4), it can be started easily even with a relatively low lighting voltage, and power consumption can be saved.

In each of the above-mentioned embodiments, argon was used as the discharge gas, but the present invention is not limited to this, and an appropriate amount of mercury may be sealed together with argon. If an alloy layer is attached, the mercury alloy layer is bombarded with electrons and ions at startup and releases mercury, making it possible to quickly start up the discharge and supply mercury for steady discharge.

Furthermore, in the present invention, the shape and number of glass bulbs does not matter; for example, three or more glass bulbs are sequentially connected in series using a two-volume closing body and an enclosure shown in FIGS. 7 and 8. Further, the valve may be U-shaped, M-shaped, etc.

Further, as long as the main part of the blocker is made of metal and the inner surface forms the discharge surface, the other parts may be made of non-metal such as glass or ceramics. Furthermore, the enclosure is limited to the above-mentioned rows. The main point is that it only needs to surround a part of the discharge surface and communicate with the discharge space, and the material of its construction does not matter.The communication part does not have to be in the form of a hole like a discharge hole. is not essential.

〔Effect of the invention〕

As described above, in the low-pressure discharge lamp of the present invention, the end face of the glass bulb is closed with a closing body whose main part is made of metal and whose inner surface constitutes the discharge surface, and the discharge surface is formed with an enclosure that communicates with the discharge space through the discharge hole. Since the plasma near the discharge is surrounded and confined, electrons and ions are emitted from the confined plasma, impacting the discharge surface and knocking out the electrons.As a result, startup is easy, lamp voltage is reduced, and power consumption is reduced. can be saved.

[Brief explanation of the drawing]

FIG. 1 is an enlarged vertical sectional front view of a main part of a first embodiment of a low-pressure discharge lamp of the present invention, FIG. 2 is a vertical sectional side view, FIG. 3 is a front view, and FIG. 4 is a side view. Figure 5 is an enlarged longitudinal sectional front view of the main part of the second embodiment, Fig. 6 is a longitudinal side view of the same, Fig. 7 is a front view of the third embodiment, and Fig. 8 is an enlarged longitudinal sectional front view of the main part. be. (11), (12)------Valve (2)------
One fluorescent film (3) --- One occlusion body (31) --
--- One body (32) --- One mounting collar (34)
----- One discharge surface (4) ----- Onai body (4
2)------One discharge hole (5)---One feeder line

Claims (1)

[Claims] A glass bulb with an open end face, a closing body whose main part is made of metal and which closes off the end face of the glass bulb and whose inner surface constitutes a discharge surface, and a discharge space surrounding a part of the discharge surface of this closure body. 1. A low-pressure discharge lamp, comprising: an enclosure that communicates with the plasma and confines the plasma near the discharge surface.