JPH05190150A - Electric discharge lamp - Google Patents

Abstract

PURPOSE:To facilitate manufacture and maintenance and reduce cost by installing a planary electrode on an electric discharge container holding body which can be easily handled, not on an electric discharge container. CONSTITUTION:An electric discharge container holding body 2 is made of hard plastic, and planary electrodes 3a and 3b are installed inside. A flurescent body layer 4 is formed, except the width in several mm, over the whole length of the inner wall of the glass bulb 1 of an electric discharge container, and xenon gas is introduced in 70Torr inside. When each voltage is supplied to the electrodes 3a and 3b through lead wires 6a and 6b from a high frequency ac power source 7, electric discharge is generated in the bulb 1 through the glass, and the generated ultraviolet ray excites the fluorescent body 4 on the inner wall, and visible light is outputted from a light output part 5. Since the electrodes 3a and 3b are installed inside the holding body 2, not on the outside surface of the bulb 1, manufacture and the replacement of the bulb 1 are facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp used for illuminating an original used in information equipment such as a facsimile, a copying machine, an image reader, an electronic bulletin board, a large display device and the like.

[0002]

2. Description of the Related Art In recent years, a fluorescent lamp has been used as a light source for illuminating a document in an information device such as a facsimile, a copying machine or an image reader. In these applications, lamps are required to be smaller, have higher brightness, have longer life, and have higher reliability. Since the conventional fluorescent lamp has a filament electrode inside the tube, there are many structural restrictions due to the electrode, and various attempts have been made to solve these problems.

FIGS. 8A and 8B show, for example, Heisei 3
FIG. 1 is a cross-sectional view showing a conventional discharge lamp shown in a proceedings collection of the 75th anniversary national convention of the Institute of Illumination.
Reference numeral 1 is a cylindrical glass bulb as a discharge vessel in which a rare gas mainly containing xenon gas is sealed, 3a and 3b.
Is a planar electrode provided on the outer surface of the glass bulb 1 in the axial direction, 4 is a phosphor layer formed on the inner surface of the glass bulb 1, and 5 is the light generated inside the glass bulb 1 irradiated to the outside of the glass bulb 1. This discharge lamp is connected to a power supply 7 which supplies a voltage between the electrodes 3a and 3b by lead wires 6a and 6b.

When a voltage is applied from the power source 7 between the external electrodes 3a and 3b, a current flows due to the electrostatic capacitance between the electrodes and discharge occurs. Due to this discharge, ultraviolet rays are generated in the glass bulb 1, and the ultraviolet rays excite the phosphor layer 4 formed on the inner surface of the glass bulb 1 to generate visible rays.

[0005]

In the above-mentioned conventional discharge lamp, a glass electrode is easily cracked, and a planar electrode is provided on the outer peripheral surface of the discharge vessel containing only a rare gas. However, there is a problem in that maintenance such as replacement of the discharge vessel is troublesome because the planar electrode is provided on the outer peripheral surface.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a discharge lamp which is easy to manufacture and maintain, thereby reducing the cost.

[0007]

DISCLOSURE OF THE INVENTION A discharge lamp according to the present invention encloses a discharge medium in a discharge vessel and excites a discharge space inside the discharge vessel on an inner surface of a discharge vessel holder that holds the discharge vessel. As described above, a plurality of planar electrodes provided in contact with the outer surface of the discharge vessel and to which a predetermined voltage is applied are provided.

According to another aspect of the invention, the discharge medium is enclosed in the discharge vessel and at least one internal electrode is provided so that the inner surface of the discharge vessel holder for holding the discharge vessel is in contact with the outer surface of the discharge vessel. It is provided with a plurality of planar electrodes which are provided and to which a predetermined voltage is applied from the outside.

Further, another invention is to provide an insulating film on the surface of the planar electrode.

[0010]

In the discharge lamp configured as described in claim 1,
The discharge container holder holds the discharge container, and applies a voltage between the planar electrodes provided inside the discharge container holder to cause discharge inside the discharge container.

According to another aspect of the discharge lamp of the present invention, the discharge container holding member holds the discharge container and applies a voltage between the planar electrode provided inside the discharge container and the internal electrode inside the discharge container. More discharge is generated inside the discharge vessel.

In the discharge lamp constructed according to the third aspect of the present invention, the planar electrode is covered with the insulating film, but discharge is caused inside the discharge vessel, and the insulating film has a function of preventing electric shock and waterproofing.

[0013]

【Example】

Example 1. An embodiment of the present invention will be described below. 1, 2 and 3 show a discharge lamp having a structure according to the present invention, FIG. 1 is an overall view of a lamp mounted on a discharge vessel holder, and FIG. 2 is a view before mounting the discharge vessel holder and the discharge vessel. FIG. 3 is a sectional view of the discharge vessel. In the figure, 1 is a glass bulb, 2 is a discharge vessel holder formed of hard plastic, 3a and 3b are planar electrodes provided inside the discharge vessel holder (on the side in contact with the glass bulb). On the inner wall of the glass bulb 1, a phosphor layer 4 is formed over the entire length except for a width of several mm. Furthermore, 7 xenon gas is contained inside the glass bulb 1.
Enclosed at 0 Torr. The portion of the glass bulb 1 where the phosphor layer 4 is not formed is a light output portion 5 for irradiating the light generated in the discharge vessel to the outside of the glass bulb. Further, 6a indicates a lead wire connected to the electrode 3a, and 6b indicates a lead wire connected to the electrode 3b, each of which is connected to a high frequency AC power supply 7 of 20 KHz.

The operation of the discharge lamp having such a configuration will be described. From the high-frequency AC power source 7, each electrode 3a, 3b
A voltage is applied to the xenon gas in the glass bulb 1 via the glass, which is a dielectric substance, which is in contact with or adjacent to the voltage, and a discharge is generated. The ultraviolet light generated by this discharge excites the phosphor 4 formed on the inner wall of the glass bulb 1, and emits visible light having a wavelength peculiar to the phosphor 4,
Visible light is output from the light output unit 5.

The principle of light emission will be described in detail below. Since the discharge lamp discharges through glass, which is a dielectric, the current is limited by the dielectric and the glow discharge does not develop into an arc discharge. Further, the discharge is not concentrated at a specific place, and the discharge is generated from the entire inner surface of the glass bulb corresponding to the external electrode. If the thickness of the glass is constant and the characteristics of the dielectric are uniform, the current density on the inner surface of the glass bulb facing the external electrode will be uniform.
The density of ultraviolet rays generated becomes almost uniform, and the generation of visible light becomes almost uniform. Therefore, the luminance distribution on the lamp surface becomes almost uniform. In addition, the current flows only immediately after the polarity of the applied voltage is reversed, and otherwise the current is stopped by the accumulation of charges on the inner surface of the glass bulb. As a result, a pulsed current flows through the lamp.

When the internal discharge state is observed in detail, the entire inner surface of the lamp facing the external electrode is covered with a substantially uniform light, and the thin thread-like discharge connecting the facing electrode is substantially constant. It can be seen that many stripes are generated at intervals. When a rare gas such as xenon is filled inside, the rare gas atoms are first excited to a resonance level by collision with electrons due to such discharge. Excited atoms at this resonance level collide with noble gas atoms at other ground levels to form excimers of diatomic molecules because the pressure of the rare gas is high. This excimer emits ultraviolet rays and returns to the two ground level noble gas atoms.

The ultraviolet rays emitted by the excimer do not undergo self-absorption like the resonance ultraviolet rays of the atoms, so most of them reach the inner wall of the lamp and are converted into visible light by the phosphor. That is, in the case of light emission by excimer, brighter light can be obtained. Further, when xenon is used as the rare gas, it is 1 in a glow discharge lamp having an electrode inside.
Xenon resonance ultraviolet rays of 47 nm are large, whereas in this discharge lamp, excimer ultraviolet rays of about 172 nm are mainly emitted. The long wavelength of ultraviolet rays is also advantageous in terms of luminous efficiency and deterioration of the phosphor.

When the surface electrodes 3a and 3b are thus provided in the socket which is the discharge vessel holder and the glass bulb 1 is mounted, the glass bulb 1 and the surface electrodes 3a and 3b inside the discharge vessel holder 2 are in contact with each other. , Form a capacitance. Therefore,
A discharge lamp having such a structure can also be discharged. Thus, the structure is not such that the planar electrode is provided on the outer peripheral surface of the glass bulb 1 in which the rare gas is sealed and is fragile, but the planar electrode is provided inside the discharge vessel holder 2 which is easy to handle. Easy maintenance and low cost.

Example 2. FIG. 4 shows an embodiment of a discharge lamp provided with internal electrodes. As shown in FIG. 4, the internal electrode 10 is provided in the glass bulb 1, and the planar electrode 3 is provided inside the discharge vessel holder (the side in contact with the glass bulb 1). In addition, the glass bulb 1 is the first embodiment.
Similarly to the above, a phosphor layer is formed on the inner wall except for a width of several mm over the entire length, and 70 Torr of xenon gas is sealed inside. The portion of the glass bulb 1 where the phosphor layer is not formed is a light output portion for irradiating the light generated inside the glass bulb 1 to the outside of the glass bulb.

Also in this embodiment, when a high-frequency AC voltage of 20 KHz is applied from the high-frequency AC power supply 7 to the inner electrode 10 and the outer electrode 3b, discharge occurs, and the same operation as in the above-mentioned first embodiment is performed to emit a light output.

Example 3. FIG. 5 is a cross-sectional view showing an embodiment of the invention which is an improvement of the first embodiment. In this embodiment, as shown in FIG. 5, the electrodes 3a, 3 provided on the discharge vessel holder 2 are
The surface of b is covered with a thin insulating film 9.

This type of discharge lamp can discharge even if the surfaces of the electrodes 3a and 3b are covered with a thin insulating film 9. Further, even if the planar electrodes 3a and 3b are not completely adhered to the glass, which is a dielectric, and a slight gap is generated, discharge is possible.
Moreover, since the surfaces of the planar electrodes 3a and 3b are covered with the insulating film 9, there is a safety and waterproof effect, and it can be used outdoors.

Example 4. In FIG. 6, a plurality of pairs of electrodes 3a to 3f are arranged adjacent to each other in the inner axial direction of the discharge vessel holder 2, and a switch 8a is provided on each lead wire connecting the plurality of pairs of electrodes 3a to 3f and the power supply 7. ~ 8c are provided. By closing desired switches of the switches 8a to 8c, only the electrode portion to which the voltage is applied discharges and emits light. Further, as in the first embodiment, the plurality of electrode pairs are attached not to the outer peripheral surface of the glass bulb 1 but to the inside of the discharge vessel holder 2 to facilitate the production.

Example 5. FIG. 7 shows a case of a discharge lamp in which a discharge vessel holder 2 which is shorter than the glass bulb 1 in the axial direction is attached, and the discharge vessel holder 2 is not fixed to the glass bulb 1 but slid to the left and right on the glass bulb 1. By doing so, it is possible to turn on only the necessary place. Although details are omitted in this figure, the glass bulb 1
Similar to the first embodiment, the above configuration and the planar electrode provided on the inner surface of the discharge vessel holder 2 are provided.

[0025]

According to the first aspect of the invention, the electrode is not provided on the outer peripheral surface of the discharge vessel, but is provided inside the discharge vessel holder (on the side in contact with the discharge vessel). This facilitates manufacturing and discharge vessel replacement.

According to the second aspect of the present invention, the electrode is not provided on the outer peripheral surface of the discharge vessel provided with at least one internal electrode, but the electrode is provided inside the discharge vessel holder (on the side in contact with the discharge vessel). By providing the structure, it becomes easy to manufacture and replace the discharge vessel.

According to the third aspect of the invention, the safety and waterproof effect are enhanced by providing the insulating film on the surface of the planar electrode.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the first embodiment of the present invention.

FIG. 3 is a sectional view showing Embodiment 1 of the present invention.

FIG. 4 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing Embodiment 3 of the present invention.

FIG. 6 is a perspective view showing Embodiment 4 of the present invention.

FIG. 7 is a perspective view showing a fifth embodiment of the present invention.

FIG. 8 is a sectional view showing a conventional discharge lamp.

[Explanation of symbols]

 1 Glass Bulb 2 Discharge Vessel Holder 3a Electrode a 3b Electrode b 4 Phosphor Layer 5 Light Output Section 7 High Frequency AC Power Supply 8 Switch 9 Insulating Film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadayuki Matsumoto 2-14-40 Ofuna, Kamakura City Mitsubishi Electric Corporation Living Systems Research Institute (72) Inventor Shigeru Akido 2-14-40 Ofuna, Kamakura City Mitsubishi Electric Corporation Company Life Systems Research Institute (72) Inventor Harumi Sawada 2-14-40 Ofuna, Kamakura City Mitsubishi Electric Corporation Life Systems Research Institute

Claims (3)

[Claims] 1. A discharge vessel in which a discharge medium is enclosed, and a discharge vessel which holds the discharge vessel and is in contact with the outer surface of the discharge vessel so as to excite an internal discharge space and to which a predetermined voltage is applied. A discharge lamp comprising a discharge container holder having a plurality of planar electrodes on its inner surface. 2. A discharge medium is enclosed inside, and
The discharge vessel provided with at least one internal electrode, and a plurality of planar electrodes for holding the discharge vessel and provided in contact with the outer surface of the discharge vessel and to which a predetermined voltage is applied from the outside are provided on the inner surface. A discharge lamp comprising a discharge vessel holder. 3. The discharge lamp according to claim 1, wherein an insulating film is provided on the surface of the planar electrode.