WO2002095792A1

WO2002095792A1 - Cold cathode discharge lamp and method of manufacturing the discharge lamp

Info

Publication number: WO2002095792A1
Application number: PCT/JP2002/003892
Authority: WO
Inventors: Hirofumi Yamashita; Haruo Yamazaki; Toshihiro Terada; Shinji Kihara
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2001-05-17
Filing date: 2002-04-18
Publication date: 2002-11-28
Also published as: CN100377289C; CN1462469A; KR20030014334A; TW564462B; KR100516607B1

Abstract

A cold cathode discharge lamp capable of being rapidly started even in such a dark place that an ambient illuminance is 0.1 lux or below, comprising electrodes (5a) installed at both end parts of a glass tube (2) having a fluorescent body layer (3) formed on the inner surface thereof and filling substance sealed therein, wherein a first film (8) formed with a start assisting metal is formed on at least one of the electrodes (5a) and a second film (9) formed with the start assisting metal is formed on the inner surface of the glass tube (2) in proximity to the first film (8), whereby a weak discharge occurs between the second film (9) and the electrode (5a) or between the second film (9) and the first film (8).

Description

Cold cathode discharge lamp and method of manufacturing the same

Technical field

The present invention relates to a cold cathode discharge lamp used for backlights of various liquid crystal display devices and the like, and particularly relates to a cold cathode discharge lamp capable of obtaining good starting characteristics even when ambient illuminance is low. .

Field technology-Cold cathode discharge lamps used in liquid crystal devices are difficult to reach the surface of the cold cathode discharge lamp due to the structure of the liquid crystal device, and the ambient illuminance near the cold cathode lamp is 10%. It tends to be in a dark environment below lux. When the cold cathode discharge lamp is started in such a dark environment, if the initial number of electrons in the cold cathode discharge lamp, which triggers discharge, is insufficient, it will start within 500 ms in an original bright environment. It takes several to several tens of seconds to start. In general, cold cathode fluorescent lamps used in liquid crystal devices are required to start immediately in a dark environment of 0.1 lux or less. Let's talk about starting.

In order to improve the dark start characteristics, Japanese Patent Application Laid-Open No. H11-112944 discloses that, in the interior of a bulb near a cold cathode, electrons are emitted in the dark with a stimulation energy lower than a work function, aluminum oxide, There is disclosed a cold cathode discharge lamp coated with an electron emitting material made of any one of metal oxides such as magnesium oxide, zinc oxide, and lead oxide. Further, Japanese Patent Application Laid-Open No. 2001-150655 discloses a cold cathode discharge lamp in which a cesium compound is applied to an electrode to improve starting characteristics. However, in the cold cathode discharge lamps configured as described above, although the dark start-up characteristics are improved, some start-ups are still slow. In addition, although the cold cathode discharge lamp coated with an electron emitting material has an average quick start-up characteristic in the dark state compared to a lamp without an electron emitting material applied to its inner surface, it still has a considerable start-up characteristic. Some slow ones were included. Disclosure of the invention

An object of the present invention is to solve the above problems and to provide a cold cathode discharge lamp that can be started more quickly even in darkness where the ambient illuminance is 0.1 lux or less. The cold-cathode discharge lamp of the present invention is a cold-cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed, and the first electrode is made of a metal for assisting starting. And a second coating made of a metal for assisting starting is provided in the glass tube in proximity to the first coating.

Further, the cold cathode discharge lamp of the present invention is characterized in that a coating made of a metal for starting assistance is provided only on the inner surface of a glass tube without providing a coating made of a metal for starting assistance on an electrode. The cold cathode discharge lamp according to claim 1 of the present invention has a phosphor layer formed on the inner surface. A cold cathode discharge lamp in which electrodes are provided at both ends of a formed glass tube and a sealed substance is sealed, and at least one electrode is provided with a first coating made of a metal for assisting starting, and said one electrode A second coating made of a metal for starting assistance is provided on the inner surface of the glass tube near the first coating in proximity to the first coating.

The cold cathode discharge lamp according to claim 2 of the present invention is characterized in that, in claim 1, the second coating is formed at a position that does not overlap with the phosphor layer formed on the inner surface of the glass tube. I do.

The cold cathode discharge lamp according to claim 3 of the present invention is characterized in that, in claim 1 or claim 2, the shape of the electrode is tubular and the first coating is provided on the outer periphery.

The cold-cathode discharge lamp according to claim 4 of the present invention is the cold cathode discharge lamp according to any one of claims 1 to 3, wherein the second coating is aluminum alloy metal or aluminum earth metal or a mixture thereof. It is characterized by.

The cold cathode discharge lamp according to claim 5 of the present invention is the cold cathode discharge lamp according to any one of claims 1 to 3, wherein the first coating is formed of an alkali metal compound, an alkaline earth metal compound, or a mixture thereof. And the second coating is formed of Al metal or Al earth metal or a mixture thereof.

A cold cathode discharge lamp according to claim 6 of the present invention is characterized in that, in claim 5, the first coating is formed of a cesium compound, and the second coating is formed of cesium.

The method for manufacturing a cold cathode discharge lamp according to claim 7 of the present invention is a method for manufacturing a cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed. At least one of the glass tubes At the other end, an electrode having a first coating of a starting assisting metal is disposed, the sealed substance is sealed, and a current exceeding a steady lighting current is applied to the electrode to age. The first coating is spun to form a second coating at a position that does not overlap with the phosphor layer formed on the inner surface of the glass tube, and the first coating is not lost from the surface of the electrode. After the aging, a first coating is formed on the surface of the electrode, and a second coating is formed on the inner surface of the glass tube. '' The cold cathode discharge lamp according to claim 8 of the present invention is a cold cathode discharge lamp having a light emitting tube in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed. A coating made of a starting auxiliary metal is provided on an inner surface of the arc tube in the vicinity of at least one of the electrodes.

The cold cathode discharge lamp according to claim 9 of the present invention is the cold cathode discharge lamp according to claim 8, wherein the starting auxiliary metal forming the coating is a rare metal in the range of 100 to 600 eV of the base metal forming the electrode. It is a metal that has a higher sputter yield than that of gas ions.

The cold cathode discharge lamp according to claim 10 of the present invention is the cold cathode discharge lamp according to claim 8 or claim 9, wherein at least the electrode on the side provided with the coating made of a starting auxiliary metal is connected to a high voltage side of a lighting circuit. It is characterized by that.

The cold cathode discharge lamp according to claim 11 of the present invention is the cold cathode discharge lamp according to any one of claims 8 to 10, wherein the electrode is a cylindrical electrode. The cold cathode discharge lamp according to any one of claims 8 to 11, wherein the coating made of the starting auxiliary metal has at least It is provided near the one electrode and on the inner surface of the glass tube where the phosphor layer is not formed.

The method for manufacturing a cold cathode discharge lamp according to claim 13 of the present invention is characterized in that, when manufacturing a cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a fluorescent layer formed on an inner surface and a sealing substance is sealed, An electrode having a starting auxiliary metal is provided at at least one end of the glass tube, and a high current exceeding a steady lighting current is supplied to the electrode having the starting auxiliary metal to perform aging. The starting assisting metal is sputtered to form a coating made of the starting assisting metal on the inner surface of the arc tube.

A method for manufacturing a cold cathode discharge lamp according to claim 14 of the present invention is characterized in that, in claim 7 or claim 13, the aging current is about two to three times the steady-state lighting current. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view showing a main part of a cold cathode discharge lamp according to (Embodiment 1) of the present invention and its XX ′ cross-sectional view. Cross section of a cold cathode discharge lamp

Fig. 3 shows the lighting probability distribution of the product of the embodiment and the comparison product.

FIG. 4 is a cross-sectional view showing a main part of a cold cathode discharge lamp according to (Embodiment 2) of the present invention and a cross-sectional view thereof along X--X '.

FIG. 5 is a cross-sectional view showing a main part of the cold cathode discharge lamp before the coating of the starting auxiliary metal in the embodiment is formed on the inner surface of the arc tube.

FIG. 6 shows a main part of the cold cathode discharge lamp according to the third embodiment of the present invention. Cross section showing

FIG. 7 is a cross-sectional view of a main part showing another example of the cold cathode discharge lamp according to the embodiment.

FIG. 8 is a cross-sectional view showing a main part of a cold cathode discharge lamp according to (Embodiment 4) of the present invention.

Fig. 9 is a diagram showing the measurement results of the start delay time of each of the embodiment products and the comparison products of (Embodiment 2) to (Embodiment 4).

Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, only one side is shown because a cold cathode discharge lamp having the same structure at both ends is taken as an example.

(Embodiment 1)

FIGS. 1 (a) and 1 (b) show (Embodiment 1) of the present invention, and FIG. 1 (b) is a cross-sectional view taken along line X-Χ 'in FIG. 1 (a).

As shown in FIG. 1, a phosphor layer 3 is formed on the inner surface of a glass tube 2, and a tube-like electrode 5a having an open end on the discharge side is provided at both ends thereof. The enclosed substance is hermetically sealed to form the arc tube 1. At least one non-discharge end of one of the electrodes 5a is connected to a metal internal lead-in 4, and the internal lead 4 is connected to an external lead 線.

The electrode 5a is provided with a first coating 8 made of a starting auxiliary metal, and the second coating 9 made of a starting auxiliary metal is formed on the inner surface of the glass tube 2 on the inner surface of the glass tube 2. It is formed at a position that does not overlap with the phosphor layer 3. ing.

The first coating 8 is formed of an alkali metal or alkaline earth metal compound or a mixture thereof, and the second coating 9 is formed of an alkali metal or alkaline earth metal or a mixture thereof. Have been. Hereinafter, a specific example will be described.

The glass tube 2 is made of a hard material made of borosilicate glass and has a total length of 300 mm, an outer diameter of 2.4 mm, and an inner diameter of 2. Omm.

. On the inner surface of the glass tube 2, the phosphor layer 3 is formed by applying a three-wavelength region light-emitting phosphor so as to have a film thickness of about 20 / m. .

The internal introduction line 4 is formed of evening stainless steel, which is a material having an expansion coefficient similar to that of the material for forming the glass tube 2. A nickel wire with an outer diameter of 0.6 mm was used as the external lead wire 7. Both ends of the glass tube 2 are made of molybdenum and have an outer diameter of 1.7 mm, an inner diameter of 1.3 mm, and a total length of 3 mn! The electrode 5a of up to 5 mm is provided. The first coating 8 has a coating amount of 10 / g or more and less than 100 μg (preferably 40 ± 20 / g) in the electrode length direction from 0.5 mm to 3 mm (preferably 1 (5 ± 0.5 mm).

The second coating 9 is formed at a predetermined position as follows.

The first coating 8 is applied to the electrode 5a, a mixed rare gas of mercury, argon and neon is sealed at about 8 kPa, and the second coating 9 is steadily applied to the luminous tube 1 not provided. The aging current that is about 2 to 3 times the lighting current, for example, when the steady-state lighting current is 8 mA, the aging current of about 18 mA to 25 mA is passed to perform aging. 5 First coating 8 applied to a Then, it is formed by being adhered to the inner surface of the glass tube 2.

Here, the aging time is ended in a state where the first coating 8 does not disappear from the surface of the electrode 5a, and the first coating 8 is left on the surface of the electrode 5a, and an appropriate film is formed on the inner surface of the glass tube 2. The time for forming the thick second film 9 is about 10 minutes.

During aging, discharge occurs from the discharge-side opening of the tube-shaped electrode 5a to the outer periphery where the first coating 8 is applied, and is spattered. Since the discharge does not reach the outer periphery where the first coating 8 is applied, the first coating 8 and the second coating 9 after aging are stable and do not disappear during use.

As described above, the first coating 8 is provided on the surface of the electrode 5a in advance, and the starting auxiliary metal is sparged by aging and adhered to the inner surface of the glass tube 2, whereby the electrode 5a is formed. It is possible to form the second coating 9 having a uniform thickness close to the second coating 9.

According to this configuration, even in a dark environment, a minute discharge occurs between the second coating 9 and the electrode 5a or between the second coating 9 and the first coating 8, and the cold cathode discharge occurs. Since the initial electrons necessary for starting are supplied into the lamp, it is possible to realize a cold cathode discharge lamp with a small decrease in initial luminance and excellent dark starting characteristics.

Using the cold cathode discharge lamp configured as described above as the product A, the dark start delay time of the following comparative product A was measured. The number of samples is 100

In the product A, the first coating 8 was formed of a cesium compound, which is one of the metallic alkali compounds, and the second coating 9 was formed of cesium, which is one of the metallic alkalis. Compared to the case where the second coating 9 was not formed as shown in Fig. 2. A

The test conditions were as follows: the test product A and the comparative product A were left in the dark of 0.1 lux ambient light for 48 hours, then the output voltage under the conditions of ambient illuminance 0.1 lux, ambient temperature 0 ° C, and no wind The dark start delay time was examined using a 1200 Vrms high frequency lighting circuit (not shown). Figure 3 shows the measurement results obtained.

As is evident from Fig. 3, 90% of the samples illuminated in 0.9 ms in Example A, whereas the time required for illumination in Comparative product A varied from 1 ms to 250 ms. As many as 6% of lamps exceeded 500 ms. In the case of Example A, a weak discharge is generated between the first coating 8 and the second coating 9 or between the second coating 9 and the first coating 8, and the discharge is generated in the low-pressure discharge lamp. The initial electrons required for starting were supplied, and a cold cathode discharge lamp with extremely good dark starting characteristics was obtained.

When the structure of the electrodes 5a at both ends is different, it is preferable that the electrode on the surface on which the first coating 8 is formed is connected to the high voltage side of the lighting circuit. .

As the material of the first coating 8, a compound such as i, K, or Rb of an alkali metal (group I of the periodic table) can be used instead of the cesium compound. Alkaline earth metals (Group II of the periodic table) such as Be, Mg, Ca, Sr, and Ba can be used.

In the above (Embodiment 1), the shape of the electrode 5a is a tube. However, even if the electrode 5a has a rod-like shape without an opening on the discharge side, the electrode 5a has a dark start characteristic compared to the conventional product. An extremely good cold cathode discharge lamp was obtained. However, in this case, in order to maintain the state of the first and second coatings 8 and 9 stably for a long period of time, the shape of the electrode 5a is set to the steady-state lighting current. It is necessary to limit it to a lower level than that of product A, which is in the form of a tube.

Furthermore, in comparison with the embodiment of Japanese Patent Application Laid-Open No. 2001-15065, in the case of Japanese Patent Application Laid-Open No. 2001-16565, cesium provided on the electrode Most of the external light reaching the compound is light attenuated by passing through the light emitting layer (corresponding to the phosphor layer 3 in the above embodiment) applied to the inside of the glass tube. As described above, the second coating 9 is formed at a position that does not overlap with the phosphor layer 3 formed on the inner surface of the glass tube 2, and external light is incident on the second coating 9 without attenuation. The present invention is different from the prior art in that good dark start characteristics cannot be expected as compared with those that generate minute discharge.

(Embodiment 2)

FIGS. 4 and 5 show (Embodiment 2) of the present invention, and FIG. 4 (b) is a cross-sectional view taken along line XX ′ in (a).

As shown in FIGS. 4 (a) and (b), a phosphor layer 3 is formed on the inner surface of the glass tube 2, and electrodes 5 b are provided on both ends thereof. Are sealed to constitute the arc tube 1. A metal internal lead-in 4 is connected to the end of the electrode 5 b on the non-firing side, and an external lead 7 is connected to the internal lead-in 4.

On the inner surface of the arc tube 1, a coating 9a made of a starting auxiliary metal is formed so as to be close to the electrode 5b.

In the cold cathode discharge lamp configured as described above, a weak discharge occurs between the electrode 5b and the coating 9a made of the starting auxiliary metal, and the initial electrons necessary for starting are supplied. An extremely good cold cathode discharge lamp is obtained. Hereinafter, a specific example will be described.

The glass tube 2 is made of a hard material made of borosilicate glass, and has a total length of 300 mm, an outer diameter of 2.4 mm, and an inner diameter of 1.8 mm. A phosphor layer 3 is formed on the inner surface of the glass tube 2 by applying a three-wavelength region light-emitting phosphor to a thickness of about 20 m.

At both ends of the glass tube 2, a rod-shaped electrode 5 b made of two beams having a total length of 5 mm and an outer diameter of 1.O mm is provided, and one end of the non-discharge side of the electrode 5 b has an outer diameter of 0. It is welded to the 8 mm internal feedthrough 4. The internal feedthrough 4 is made of stainless steel whose expansion coefficient is similar to the material used to form the glass tube 2. Both ends of the arc tube 1 are sealed by the internal feedthrough 4 and the glass tube 2. A rare gas mixture (not shown) of mercury, argon, and neon is sealed in the arc tube 1 at about 8 kPa. Note that the other end of the internal lead-in wire 4 whose one end is connected to the electrode 5b is connected to a nickel external lead-in wire 7 having an outer diameter of 0.6 mm.

On the inner surface of the arc tube 1 in the vicinity of the electrode 5b, a coating 9a having a thickness of 2 zm made of a starting metal is formed. The starting auxiliary metal is made of a metal with a sputter yield greater than the sputter yield of rare gas ions in the range of 100 to 600 eV of the base metal of electrode 5b. Nickel having a higher sputtering yield than diobium, which is a base metal, is used.

This coating 9a is formed by the following procedure.

On the surface of the two-beam forming the electrode 5b, a small-sized rare-ion gas ion (at oms / ion) of 100 to 600 eV with a sputter yield (at oms / ion) larger than that of the two-beam is used for the electrolytic and electric plating. It is applied by a method such as evaporation. Nickel film thickness As described above, the thickness is set to about 5 / m so that the thickness of the coating 8a formed on the inner surface of the arc tube 1 is about 2 / m.

An internal lead wire 4 is connected to one end of an electrode 5b having nickel adhered to the surface of the objet by laser welding or the like, and a cold cathode discharge lamp is assembled by a normal manufacturing method.

FIG. 5 shows a state immediately after the cold cathode discharge lamp shown in FIG. In this state, the coating 9a is not formed on the inner surface of the arc tube 1, and nickel as a starting auxiliary metal is applied to the surface of the electrode 5b to form the coating 8a.

Next, when a high current of 6 mA or more, which is a normal lighting current, for example, a current of 15 mA is supplied to the electrode 5b and aging is performed for about 2 hours, the electrode 5b is exposed to the surface of the diode during aging. The deposited nickel is spun and adheres to the inner surface of the arc tube 1 close to the electrode 5b to form a coating 9a having a thickness of about 2 m.

In this way, a coating 8a made of a starting auxiliary metal is provided on the surface of the electrode 5b in advance, and the starting auxiliary metal is sparged by aging and adhered to the inner surface of the arc tube 1, whereby the electrode 5b is formed. The start-up assisting metal coating 9a having a uniform film thickness can be formed in a short time on the inner surface of the arc tube 1 close to the light source. Can be easily realized.

Using the cold cathode discharge lamp prepared as described above as product B, the dark startability was examined as follows.

The test conditions were as follows: Product B was left in the dark of 0.1 lux of ambient light for 48 hours, and then the output voltage was 120 lux under the conditions of 0.1 lux ambient light, 0 ° C ambient temperature, and no wind. Using a high-frequency lighting circuit (not shown) of 0 V rms The dark start delay time was examined. Figure 9 shows the measurement results obtained.

For comparison, instead of the nickel coating 9a, lead oxide, which is a metal oxide electron-emitting substance that emits electrons in the dark with a stimulation energy lower than the work function, is placed on the inner surface of the arc tube 1 in the dark. By coating, a cathode discharge lamp was prepared. Using this cold cathode discharge lamp as a comparative product B, the dark start delay time was examined under the same test conditions as above. Figure 9 shows the measurement results of the obtained comparative product B.

As is evident from Fig. 9, there is almost no difference in the average dark start delay time between the test product B and the comparative product B, but the maximum dark start delay time is 603 O msec of the comparative product B. On the other hand, the sample B was 28 O.msec, and there was no large delay like the sample B. As described above, in the embodiment B of the second embodiment, the electrode 5b and the starting auxiliary metal are provided on the inner surface of the arc tube 1 by providing the coating 9a made of the starting auxiliary metal close to the electrode 5b. More: Since a weak discharge is generated between the coatings 9a and the initial electrons necessary for starting are supplied into the low-pressure discharge lamp, a cold cathode discharge lamp having extremely good dark start characteristics was obtained. '

In addition, as shown in FIG. 5 described above, it is preferable that the electrode 5 a on which the coating 8 a made of the metal for starting assistance is formed is connected to the high voltage side of the lighting circuit. That is, in the above-described embodiment B, since the both ends of the low-pressure discharge lamp have the same structure, the electrode 5b on which the coating 8a is formed is connected to the high-voltage side of the lighting circuit. When the structure of the part is different, it is preferable that the electrode on the surface of which the auxiliary metal for starting is provided is connected to the high voltage side of the lighting circuit.

In order to confirm this, both ends of the low-pressure discharge lamp have different structures. A cold cathode discharge lamp was prepared, and was designated as a working product C. The electrode on the side of the lighting circuit where the coating 8a made of a metal for assistance was not provided was connected to the high voltage side of the lighting circuit, and the dark starting delay time was measured under the same conditions as for the working example B. The number of samples was 100. Figure 9 shows the measurement results obtained.

As is evident from Fig. 9, the dark start characteristics of the product C, in which the electrode on which the starting auxiliary metal 8a was not provided was connected to the high voltage side of the lighting circuit, were also better than the comparative product B. However, the average dark start delay time of Example C is as large as 25 O msec, and the maximum dark start delay time is 48 O msec, compared with Example B above.

This is because, when the output voltage of the high-frequency lighting circuit is applied, the electric field between the electrode that is short distance and the film made of the starting auxiliary metal becomes strong.Therefore, initial discharge occurs between the electrode and the film made of the starting auxiliary metal, This is probably because the initial electrons necessary for starting the lamp are supplied into the low-pressure discharge lamp. In this way, by connecting the electrode on the side where the metal for starting assistance is provided to the high voltage side of the lighting circuit, dark startability can be significantly improved.

In the above description, an example in which the surface of the electrode 5b is covered with the film 8a made of the auxiliary metal for starting is described. However, the present invention is not limited to this. It is sufficient that the starting metal is provided on the surface of b.

(Embodiment 3)

FIG. 6 shows (Embodiment 3) of the present invention.

In this (Embodiment 3), a tube-shaped electrode 5a is used instead of the rod-shaped electrode 5b, and the inner surface of the arc tube 1 close to the opening of the electrode 5a is started. This embodiment is different from the above embodiment in that a coating 9b made of a movement assisting metal is formed.

Specifically, the electrode 5a is made of molybdenum, and has an outer diameter of 1.5 mm, an inner diameter of 1.3 mm, and a total length of 3 m'm. On the inner surface of the arc tube 1 close to the opening of the electrode 5a, a coating 8b of nickel having a thickness of 2 μm is formed as a starting auxiliary metal. '

The coating 9b is formed by forming a nickel film having a thickness of about 5 m in advance on the inner surface of the electrode 5a by a sputter deposition method, and a high current of 6 mA or more, which is a normal lighting current, for example, about 2 to 3 times. By passing a current of 15 mA to the electrode 5a and aging for about 2 hours, the nickel deposited on the inner surface of the electrode 5a is sparged during aging, and It is formed so as to adhere to the inner surface of the arc tube 1 close to the opening a. '

With the cold cathode discharge lamp configured as described above as the product D, the electrode 5a having a nickel film formed on the inner surface thereof was connected to the high voltage side of the lighting circuit, and the same conditions as in the above (Embodiment 2) were applied. The dark start delay time was measured. The number of samples was 100. Fig. 9 shows the obtained measurement results. 'As shown in Fig. 9, the average dark start delay time of the product D is 70 msec, and the maximum dark start delay time is 15 O msec'. It was even better than the dark start characteristics of product B. As described above, the tube-shaped electrode 5a is used as an electrode, and the auxiliary metal for starting provided on the inner surface thereof is applied to the inner surface of the arc tube 1 by aging, whereby the coating 9b composed of the electrode 5a and the auxiliary metal for starting is formed. Is shorter than that of the cold cathode discharge lamp in the above (Embodiment 2), and the electric field between the electrode 5a and the coating 9b becomes stronger, so that the initial electrons necessary for starting can be more easily supplied. As a result, the dark start characteristics have been significantly improved. Wear.

Further, in the above description, a film made of a starting auxiliary metal is formed on the inner surface of the electrode 5a, and the film is formed on the inner surface of the arc tube 1 by aging to form a film 9b. Without limitation, as shown in FIG. 7, a coating 8b made of an auxiliary metal for starting is formed on the outer surface of the electrode 5a, and the coating 8b is similarly sputtered by aging to form the arc tube 1. A coating 9c may be formed on the inner surface of the substrate. In Fig. 7, by performing aging for about 30 minutes with a current of 2 O mA higher than that described above, the number of electrons required for discharge cannot be secured only on the inner surface of the electrode. Part of the electrode 5a wraps from the inside to the outer surface near the opening, and the spattering near the opening where the electrode 5a has a strong wraparound becomes stronger. 5a thinner towards the open end. However, by further increasing the aging current, the discharge can be spread over the entire outer peripheral surface of the cylindrical electrode 5b, and the coating 8b is sufficiently sputtered, for example, as shown in coating 9a in FIG. can do.

(Embodiment 4) ''

FIG. 8 shows (Embodiment 4) of the present invention.

This embodiment is different from the above (Embodiment 3) in that the coating 9d is formed near the electrode 5a and on the inner surface of the arc tube 1 where the phosphor layer 3 is not formed.

That is, the cold cathode discharge lamp in this embodiment is different from the cold cathode discharge lamps shown in FIGS. 6 and 7 in that the phosphor layer 3 does not extend to a position facing the outer surface of the electrode 5a. , Near the open end of electrode 5a The glass tube 2 is exposed from the inner surface of the light tube 1, and a coating 9d made of a starting auxiliary metal is formed near the opening end of the electrode 5a.

In this way, the starting metal is spun directly on the inner surface of the glass tube 2 having good surface smoothness, not on the phosphor layer 3, to form the coating 9d, thereby forming a coating of several microns on the surface. A more accurate coating 9d can be obtained than the coating formed on the phosphor layer 3 having irregularities.

Using the cold cathode discharge lamp configured as described above as the product E, the electrode 5a was connected to the high voltage side of the lighting circuit, and the dark start delay time was measured under the same conditions as in the above (Embodiment 2). The number of samples was 10.0. Figure 9 shows the measurement results obtained.

As shown in FIG. 9, the average dark start delay time of Example E is 3 O msec, and the maximum dark start delay time is 120 ms, which is greater than that of Example D in the above (Embodiment 3). Furthermore, it had good dark start characteristics. In each of the above embodiments, the electrodes 5a and 5b have been described as being made of a single metal as an example. However, the present invention is not limited to this. Metals can also be used, and furthermore, single metals, alloys, and sintered metals can be appropriately combined.

In each of the above embodiments, the cold cathode discharge lamp has the same structure at both ends as an example. However, the present invention is not limited to this. Should be configured as above o

The cold cathode discharge lamp of the present invention is not limited to the above embodiments, and its dimensions, design, material, shape, rating, and the like can be appropriately selected. Further, the electrode is not limited to the above-mentioned rod-shaped electrode or sleeve-shaped electrode, and may be, for example, a cylindrical electrode having a bottom or no bottom. It is not particularly limited as long as it has a practical effect, such as an electrode having a structure of two or more layers or a sleeve-shaped electrode having an inner surface coated with an emissive substance. Absent. -As described above, the cold cathode discharge lamp of the present invention is a cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed, and at least one of the electrodes has Providing a first coating made of a starting aid metal, and providing a second coating made of a starting assistance metal on the inner surface of the glass tube in the vicinity of the one electrode in close proximity to the first coating. Weak discharge between the first coating and the second coating made of the metal for starting assistance, which generates dark electrons and supplies the initial electrons necessary for starting into the cold cathode discharge lamp, resulting in dark start characteristics. Is extremely good.

In addition, the method for manufacturing a cold cathode discharge lamp of the present invention is a method for manufacturing a cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed. At least one end of the tube is provided with an electrode having a first coating of a metal for start-up assistance, the sealed substance is sealed, and a current exceeding a steady lighting current is passed through the electrode to age. Forming a second coating at a position that does not overlap with the phosphor layer formed on the inner surface of the glass tube by sputtering the first coating, so that the first coating does not disappear from the surface of the electrode. After the aging, the L-th coating is formed on the surface of the electrode and the second coating is formed on the inner surface of the glass tube, so that the cold cathode discharge lamp of the present invention can be easily realized.

Further, the cold cathode discharge lamp of the present invention is a cold cathode discharge lamp having a light emitting tube in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed. In a cathode discharge lamp, by providing a coating made of a starting aid metal on the inner surface of the arc tube at least near one of the electrodes, a weak discharge is generated between the coating made of the starting aid metal and the electrode. As a result, the initial electrons required for starting are supplied to the cold cathode discharge lamp, so that a cold cathode discharge lamp having extremely good dark start characteristics can be obtained.

The method of manufacturing a cold cathode discharge lamp of the present invention is used for manufacturing a cold cathode discharge lamp having an arc tube in which electrodes are provided at both ends of a glass tube having a fluorescent layer formed on the inner surface and a sealed substance is sealed. At least one end of the glass tube is provided with an electrode having a metal for starting assistance, and the electrode on the side having the metal for starting assistance is supplied with a high current that is equal to or higher than a steady lighting current to perform aging. Since the starting auxiliary metal is sputtered by aging to form a coating made of the starting auxiliary metal on the inner surface of the arc tube, the cold cathode discharge lamp of the present invention can be easily realized.

Claims

The scope of the claims

1.

A cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on the inner surface to seal the enclosed material,

At least one electrode is provided with a first coating made of a starting aid metal,

A second coating made of a starting aid metal was provided on the inner surface of the glass tube near the one electrode in proximity to the first coating.

.Cold cathode discharge lamp.

2.

The second coating was formed at a position not overlapping with the phosphor layer formed on the inner surface of the glass tube.

The cold cathode discharge lamp according to claim 1.

3.

3. The cold cathode discharge lamp according to claim 1, wherein the electrode has a tubular shape and the first coating is provided on an outer periphery.

Four .

The second coating is Al-Li metal or Al-earth metal or a mixture thereof

The cold cathode discharge lamp according to claim 1.

Five .

Forming a first coating of an alkali metal or alkaline earth metal compound or a mixture thereof;

The second coating was formed from Al-Li metal or Al-earth metal or a mixture thereof

The cold cathode discharge lamp according to claim 1.

6.

The first coating was formed with a cesium compound, and the second coating was formed with cesium

A cold cathode discharge lamp according to claim 5. '

7.

In manufacturing a cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed,

At least one end of the glass tube is provided with an electrode having a first film of a metal for assisting starting, and sealing material is sealed;

The electrode is aged by passing a current exceeding a steady lighting current, and the first coating is sputtered by the aging, and the first coating is spliced to a position not overlapping with the phosphor layer formed on the inner surface of the glass tube. 2 to form a coating,

The aging is terminated in a state where the first coating does not disappear from the surface of the electrode, and a first coating is formed on the surface of the electrode and a second coating is formed on the inner surface of the glass tube.

Manufacturing method of cold cathode discharge lamp.

8.

A cold cathode discharge lamp having a light emitting tube in which electrodes are provided at both ends of a glass tube having a phosphor layer formed on an inner surface and a sealed substance is sealed,

At least a coating made of a starting auxiliary metal was provided on the inner surface of the arc tube near one of the electrodes.

Cold cathode discharge lamp.

9.

The starting auxiliary metal forming the coating is a metal having a higher sputter yield than the sputter yield of the base metal forming the electrode due to a rare gas ion in a range of 100 to 600 eV.

9. The cold cathode discharge lamp according to claim 8.

Ten .

: At least the electrode on the side provided with the film made of a metal for starting assistance is connected to the high voltage side of the lighting circuit.

10. The cold cathode discharge lamp according to claim 8 or claim 9.

1 1.

The electrode is a cylindrical electrode

The cold cathode discharge lamp according to any one of claims 8 to 10.

1 2.

Check that the coating made of the starting aid metal is near at least one of the electrodes. Provided on the inner surface of the arc tube where no phosphor layer is formed

The cold cathode discharge lamp according to any one of claims 8 to 11.

13 .

When manufacturing a cold cathode discharge lamp in which electrodes are provided at both ends of a glass tube with a fluorescent layer formed on the inner surface and the sealed substance is sealed,

An electrode having a starting aid metal is provided on at least one end of the glass tube, and aging is performed by passing a high current exceeding a steady lighting current to the electrode having the starting assist metal,

By this aging, the starting assisting metal is spun to form a coating made of the starting assisting metal on the inner surface of the arc tube.

Manufacturing method of cold cathode discharge lamp. ·

14 .

Aging current is about 2 to 3 times of steady lighting current

'The method for producing a cold cathode discharge lamp according to claim 7 or claim 13.