JP4818054B2 - Low pressure nitrogen gas discharge lamp - Google Patents

Description

  The present invention relates to a low-pressure nitrogen gas discharge lamp in which nitrogen gas is enclosed as a luminescent gas.

  Conventionally, mercury fluorescent lamps have been used for general lighting and backlights. However, since there is concern about the influence of mercury on the environment, silver-free mercury is desired. Nitrogen gas is used as luminescent gas instead of mercury for mercury-free. However, there is a problem that nitrogen is consumed (cleaned up) by adsorbing to the internal electrode and the glass tube during discharge. Therefore, by pre-processing by discharge before sealing the mixed gas of argon and nitrogen into the lamp, adsorption to the electrode and glass tube during discharge can be prevented to some extent, and the rate of nitrogen consumption is suppressed. Has been reported (for example, see Non-Patent Document 1).

  In addition, a characteristic that does not depend on ambient temperature is desired, and a rare gas lamp using xenon (Xe) as a luminescent gas has been studied. A cleanup phenomenon in which xenon disappears from the discharge space has also been reported, and in order to suppress this, it has been proposed to form an isolation film on the inner surface of the bulb. However, this is a xenon (monoatomic molecule with very low reactivity) discharge and is different from nitrogen (diatomic molecule) discharge (see, for example, Patent Document 1 and Non-Patent Document 2).

On the other hand, in a low-pressure mercury vapor discharge fluorescent lamp using mercury, glass component sodium (Na) diffuses and moves in the phosphor layer and reacts with mercury on the phosphor layer to reduce the luminous flux maintenance rate. In order to suppress this, it has been proposed to form a protective film (isolation film) on the inner surface of the glass tube (see, for example, Patent Document 2 and Patent Document 3).
Japanese Patent Publication No. 8-3993 Japanese Patent Publication No. 36-7240 Japanese Patent Publication No. 50-35967 "Countermeasures against nitrogen consumption in argon-nitrogen mixed gas discharge tubes" 2006 Lighting Society 39th National Convention, Tatsuya Matsuda, etc. “Hot cathode type rare gas discharge fluorescent lamp (1) Basic characteristics” 39th National Convention of Lighting Society of Japan, Takashi Osawa et al.

  In a lamp that uses nitrogen gas as the luminescent gas, pretreatment by discharge before sealing the mixed gas of argon and nitrogen into the lamp can prevent the adsorption of the nitrogen to the electrode and glass tube during discharge to some extent. Although it is possible to reduce the rate of nitrogen consumption, the pretreatment by discharge has problems of time loss and complicated processes.

  Therefore, the inventors have come up with a rare gas discharge experience in the past, and came up with the idea of using a separator without pretreatment by discharge. However, the xenon is a very large monoatomic molecule and has very little reactivity. Moreover, the nitrogen atom, which is a diatomic molecule that is very small compared to xenon, has a different disappearance mechanism, so that the same form could not provide a sufficient nitrogen disappearance suppressing effect.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a low-pressure nitrogen gas discharge lamp capable of obtaining a sufficient nitrogen disappearance suppressing effect without performing pretreatment by discharge. .

  The low-pressure nitrogen gas discharge lamp according to the present invention is a low-pressure nitrogen gas discharge lamp in which nitrogen gas is enclosed as a luminescent gas in a glass bulb and light emitted from the nitrogen gas is emitted by discharge. An isolation film for the discharge space is provided in the surrounding portion, and the isolation film is thicker than that used in the low-pressure rare gas discharge lamp.

In the low-pressure nitrogen gas discharge lamp according to the present invention, the isolation film is a titanium oxide (TiO ₂ ) thin film.

  The low-pressure nitrogen gas discharge lamp according to the present invention is characterized in that the titanium oxide has translucency formed by thermally decomposing tetrabutyl titanate.

  In the low-pressure nitrogen gas discharge lamp according to the present invention, the isolation film provided on the inner surface of the glass tube is thicker than that used in the low-pressure rare gas discharge lamp, so that the nitrogen gas sealed in the bulb and the residue in the glass bulb are Therefore, the disappearance of nitrogen can be suppressed without pretreatment by discharge.

Embodiment 1 FIG.
1 and FIG. 2 are diagrams showing Embodiment 1, FIG. 1 is a partial plan view in which a part of a low-pressure nitrogen gas discharge lamp 1 is broken, and FIG. 2 is a diagram of the low-pressure nitrogen gas discharge lamp 1 using a titanium oxide film. It is a lifetime characteristic view. FIG. 3 is a reference diagram and is a life characteristic diagram of a low-pressure rare gas discharge lamp using a titanium oxide film.

  In FIG. 1, a low-pressure nitrogen gas discharge lamp 1 mainly used as a light source for OA-related equipment uses a glass bulb 2 having a tube diameter of 15.5 mm, for example. This glass bulb 2 is a very general soda glass containing fluorine as a residue and 0.004% by weight of chlorine and 0.031% by weight of chlorine.

  On the inner surface of the glass bulb 2, a separation film 3 made of a titanium oxide film is formed. The titanium oxide film is obtained by applying and drying tetrabutyl titanate and baking and decomposing it. The isolation film 3 does not need to be formed on the entire inner surface of the glass bulb 2, and may be provided at least on the portion of the inner surface of the glass bulb that surrounds the positive column formed by the discharge between the electrodes (filaments 7).

  A reflection film 4 that reflects light is formed on the isolation film 3.

  Further, a phosphor layer 5 is provided on the inner surface of the reflective film 4.

  Since the low-pressure nitrogen gas discharge lamp 1 is mainly used as a light source for OA related equipment, an aperture opening 6 that radiates light reflected from the reflective film 4 is formed in the longitudinal direction of the glass bulb 2. ing. Naturally, the reflective film 4 is not formed in the aperture opening 6.

  An electron-emitting material is applied to the filament 7 serving as an electrode.

  Inside the glass bulb 2, a mixed gas (argon: 90%, nitrogen: 10%) is sealed at about 133 Pa (1 Torr).

  The lighting conditions were a 45 KHz sine wave harmonic, and the lamp current was constant at 100 mA.

FIG. 2 shows the lifetime (relative value) when the sealed gas pressure is changed in the low-pressure nitrogen gas discharge lamp 1 configured as described above. As a parameter, the amount of titanium oxide that is the isolation film 3 on the inner surface of the glass bulb was taken. That is, the curve (solid line) shown in FIG. 2 has a titanium oxide adhesion amount of 0 (mg / cm ² ), and the curve i (one-dot chain line) has a titanium oxide adhesion amount of 0.001 (mg / cm ² ). (Dash-dotted line) is the case where the titanium oxide adhesion amount is 0.005 (mg / cm ² ), and curve D (dashed line) is the case where the titanium oxide adhesion amount is 0.05 (mg / cm ² ).

  The lifetime of the low-pressure nitrogen gas discharge lamp 1 means a time when the nitrogen gas spectrum generated by the discharge substantially disappears, and argon gas enclosed as a buffer gas emits light instead, and the emission spectrum becomes dominant. . The lifetime was expressed as a relative value with the lifetime when pure nitrogen gas 13300 Pa (about 100 Torr) was sealed as 100%.

  2 that the lifetime of the low-pressure nitrogen gas discharge lamp 1 is dramatically extended by increasing the amount of titanium oxide attached.

  For reference, FIG. 3 shows the life characteristics of a low-pressure rare gas discharge lamp using a titanium oxide film. It can be seen that the amount of titanium oxide deposition that suppresses the cleanup phenomenon in which xenon disappears from the discharge space may be less than that of the low-pressure nitrogen gas discharge lamp 1 of FIG. In other words, in the low-pressure nitrogen gas discharge lamp 1, it is necessary to increase the amount of titanium oxide adhesion (thickness of the isolation film 3) 5 to 10 times in order to suppress the cleanup phenomenon as compared with the low-pressure rare gas discharge lamp. There is.

  In another experiment, aluminum oxide and silicon oxide were tested as the isolation film 3, but the effect of suppressing nitrogen disappearance could not be confirmed. This also seems to be different from the ordinary mercury vapor discharge fluorescent lamp, and it was presumed that it was close to the action of suppressing the xenon cleanup of the low pressure rare gas discharge lamp.

FIG. 2 is a diagram showing the first embodiment and is a partial plan view in which a part of the low-pressure nitrogen gas discharge lamp 1 is broken. FIG. 5 is a diagram showing the first embodiment and is a life characteristic diagram of a low-pressure nitrogen gas discharge lamp 1 using a titanium oxide film. It is a reference figure and is a lifetime characteristic view of the low-pressure noble gas discharge lamp using a titanium oxide film.

Explanation of symbols

  1 low-pressure nitrogen gas discharge lamp, 2 glass bulb, 3 separator, 4 reflective film, 5 phosphor layer, 6 aperture opening, 7 filament.

Claims (5)

In a low-pressure nitrogen gas discharge lamp that encloses nitrogen gas as a luminescent gas in a glass bulb and uses the light emitted by the nitrogen gas by discharge,
In the part surrounding at least the positive column on the inner surface of the glass bulb, an isolation film from the discharge space is provided,
The isolation film is a titanium oxide (TiO ₂ ) thin film having an adhesion amount of 0.005 mg / cm ² or more ,
A low-pressure nitrogen gas discharge lamp , wherein nitrogen gas of 0.05 x 133 Pa (Pascal) to 100 x 133 Pa is enclosed in the glass bulb . The separator is adhered amount of 0.05 mg / cm ² or more titanium dioxide (TiO ₂₎ low-pressure nitrogen gas discharge lamp according to claim 1, characterized in that a thin film. The titanium oxide claim 1 or 2 low-pressure nitrogen gas discharge lamp according to, characterized in that a light-transmitting which is formed by thermal decomposition of tetrabutyl titanate. The low-pressure nitrogen gas discharge lamp according to any one of claims 1 to 3, wherein the low-pressure nitrogen gas discharge lamp is a discharge lamp in which nitrogen gas of 0.1 x 133 Pa to 10 x 133 Pa is sealed.   The low-pressure nitrogen gas discharge lamp has an aperture opening that emits light in the longitudinal direction of the glass bulb, has the isolation film on the entire inner surface of the glass bulb, and emits light on the inner surface of the isolation film other than the aperture opening. 5. The low-pressure nitrogen gas discharge lamp according to claim 1, wherein the low-pressure nitrogen gas discharge lamp has a reflective film that reflects light and has a phosphor layer on an inner surface of the reflective film.

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