JPH09306432A - Small fluorescent tube and small fluorescent tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small fluorescent tube and a small sized fluorescent tube device shortening a brightness rise up time. SOLUTION: This small sized fluorescent tube has a tube type seal 11 of 5mm of less internal diameter a and a pair of electrodes 14 arranged so as to be mutually opposed in this seal 11, a value of ratio S/P of a sectional area S(m<2> ) of the seal 11 to input power P(W/m) per unit length of the seal 11 satisfies a condition 0.05×10<-6> <=S/P<=0.45×10<-6> .

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a small fluorescent tube,
More specifically, the present invention relates to a small fluorescent tube having a sealed body with an inner diameter of 5 mm or less, which is used for a backlight of a liquid crystal display device, a light source for a scanner device, a light source for an ultraviolet fixing device, a light source for general illumination and the like.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been used in various fields, and portable devices have been developed. A small fluorescent tube is preferably used as the backlight of the liquid crystal display device. Also,
Recently, small fluorescent tubes have been widely used as light sources for scanner devices, ultraviolet fixing devices, and the like.

However, in a conventional small fluorescent tube, particularly in a small fluorescent tube having an inner diameter of 5 mm or less,
There is a problem that the rise time from the start of supplying power to the small fluorescent tube until the brightness of the small fluorescent tube becomes high, and this phenomenon is remarkable when the environmental temperature is low. This phenomenon occurs because the ratio of input power to the heat capacity of the envelope of the small fluorescent tube is small,
Also, since the heat of the small fluorescent tube is taken by peripheral members such as a holding member that holds the sealed body of the small fluorescent tube, the temperature inside the sealed body of the small fluorescent tube cannot be increased in a short time.

Conventionally, as means for shortening the rise time of the brightness of a small fluorescent tube, only a specific time after the start of lighting,
A means for raising the temperature inside the envelope by supplying excess power that is larger than the input power during steady lighting is known. However, in a small fluorescent tube having a sealed body with an inner diameter of 5 mm or less, a small size electrode is used as a matter of course, and even if excess power is supplied, a current larger than a certain amount cannot flow. Therefore, the temperature inside the envelope does not rise in a short time, and eventually the rise time of the luminance cannot be shortened.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
It is an object of the present invention to provide a small fluorescent tube having a short rise time of brightness and a small fluorescent tube device including the small fluorescent tube.

[0006]

The small fluorescent tube of the present invention comprises:
What is claimed is: 1. A small fluorescent tube comprising a tubular envelope having an inner diameter of 5 mm or less, and a pair of electrodes arranged inside the envelope so as to face each other, and having a cross-sectional area S (m ² ) of the envelope. The value of the ratio S / P to the input power P (W / m) per unit length of the envelope satisfies the following condition. Condition 0.05 × 10 ^-6 ≦ S / P ≦ 0.45 × 10 ^-6

In the above-mentioned small fluorescent tube, excessive power of 1.1 to 2.0 times the input power at the time of steady lighting is supplied for a set time within a range of 10 to 60 seconds after the start of lighting. Is preferably turned on.

The small fluorescent tube device of the present invention comprises the above-mentioned small fluorescent tube and a holding member provided so as to hold the sealed body of the small fluorescent tube, and each electrode of the small fluorescent tube is made of metal. The holding member comprises a sleeve and a filament arranged so as to be housed in the cylindrical hole of the metal sleeve, and the holding member is located at a position of 5 mm from the both ends of the envelope of the small fluorescent tube to the inside or at a position inside thereof. It is characterized in that it is provided in the area.

The small fluorescent tube device of the present invention comprises the above small fluorescent tube and a holding member provided to hold the sealing body of the small fluorescent tube, and each electrode of the small fluorescent tube is The holding member is made of a metal sleeve or a metal rod and is provided in a region between both ends of the sealed body of the small fluorescent tube and a position 5 mm inward from the both ends.

[0010]

Embodiments of the present invention will be described below in detail. FIG. 1 is an explanatory sectional view showing the structure of an example of the small fluorescent tube of the present invention. In this small fluorescent tube 10, a sealing portion 12 is formed at each end of a glass straight tube type sealing body 11 having an inner diameter a of 5 mm or less, and each sealing portion 12 is hermetically sealed. There is provided a lead wire 13 penetrating through and extending in the axial direction of the envelope 11. At the inner end of each of the lead wires 13, the sealing body 11
The electrodes 14 are provided so as to face each other in the axial direction. Further, a phosphor layer 17 having a thickness of, for example, 10 to 30 μm is formed on the inner peripheral surface of the envelope 11. Then, mercury and a rare gas are enclosed in the envelope 11.

The electrode 14 in this example is a double-coil filament made of tungsten having a metal sleeve 15 made of, for example, stainless steel or nickel, and an emitter made of, for example, (Ba, Sr, Ca) O applied on the surface. 16 is a hot cathode type, and the metal sleeve 15 is arranged along the axial direction of the sealing body 11 so that the openings thereof face each other, and the filament 16 is housed inside the metal sleeve 15. It is arranged to be done.

More specifically, the metal sleeve 15 is held by the lead wire 13 in such a state that the distal end of the lead wire 13 is sandwiched by, for example, a flat crushed base end so that the openings thereof face each other. ing. The filament 16 has its proximal end pinched and fixed by the proximal end of the crushed metal sleeve 15, and its distal end is positioned inward without exceeding the distal end of the metal sleeve 15.
It is arranged in the cylindrical hole of the metal sleeve 15.

By using the electrode 14 having such a metal sleeve 15, it is possible to reduce the scattered substances generated from the filament 16, so that the blackening phenomenon of the sealing body 11 is suppressed and, as a result, the long service life is obtained. Is obtained.

It is preferable to use lead glass, kovar glass, or borosilicate glass as the material for forming the envelope 11, and this provides a sufficiently high strength even when the inside diameter a of the envelope 11 is 5 mm or less. Will have.

As the material for the lead wire 13, there may be used Dumet wire, a Kovar wire, a tungsten wire, etc., in which a core wire made of a nickel alloy is coated with copper. When the envelope 11 is made of lead glass, it is preferable to use Dumet wire, and when the envelope 11 is made of Kovar glass, Kovar is preferably used. The coefficient of thermal expansion of Dumet wire is very close to the coefficient of thermal expansion of lead glass, while the coefficient of thermal expansion of Kovar is very close to the coefficient of thermal expansion of Kovar glass. 1
3 can be directly sealed in a highly airtight state, it is not necessary to employ a special sealing structure, and the sealing portion 12 can be advantageously used even if the inner diameter a of the sealing body 11 is 5 mm or less. Can be formed.

In the small fluorescent tube having the hot cathode type electrode 14 as described above, it is preferable that the rare gas sealed in the sealing body 11 contains argon and krypton as the main components. It is preferable that the ratio of krypton in all rare gases is 10 to 50 mol%. Also,
The filling pressure of the rare gas is preferably 20 to 80 Torr. By satisfying such conditions, a small fluorescent tube having a low starting voltage and a high luminance can be obtained.

In the present invention, the cross-sectional area S of the envelope 11 is
(M ² ) [In FIG. 1, S = π (b / 2) ² −π (a
/ 2) ² and b are outer diameters of the sealed body. ] And the input power P (W / m) per unit length of the envelope 11 has a value of a ratio S / P (hereinafter, also simply referred to as “ratio S / P”) of 0.05 × 1.
0 ^{-6 to} 0.45 x 10 ^-6 , preferably 0.05 x 10 ^-6
It is set to 0.3 × 10 ⁻⁶ . The value of ratio S / P is 0.45 ×
If it exceeds 10 ⁻⁶ , a small fluorescent tube having a short rise time of luminance cannot be obtained. On the other hand, when the value of the ratio S / P is less than 0.05 × 10 ⁻⁶ , the wall thickness of the envelope is too small to obtain sufficient strength.

According to the above configuration, the cross-sectional area S of the envelope 11 is
Ratio of input power P per unit length of the envelope 11 to S / P
Since the value of is within a specific range, it is possible to obtain the small fluorescent tube 10 in which the rise time of the brightness is short, as is apparent from the examples described later.

In the small fluorescent tube of the present invention, the inner diameter is 5
Other configurations are not particularly limited as long as it has a sealed body of mm or less and the ratio S / P value is within the above range. For example, the electrode is a cold cathode made of a metal sleeve or a metal rod. It may be of a mold. FIG. 2 shows an example of the structure of a small fluorescent tube of the present invention having a cold cathode type electrode. In this small fluorescent tube 20, as in the small fluorescent tube 10 shown in FIG. 1, the sealing body 11, the lead wire 13, and the fluorescent layer 1 are provided.
7 are provided, and mercury and a rare gas are sealed in the sealing body 11. Each of the electrodes 21 is a cold cathode type which is composed of a metal sleeve made of nickel, stainless steel, or the like. Specifically, each of the electrodes 21 is held by the lead wire 13 with the openings thereof facing each other by sandwiching the tip end portion of the lead wire 13 by the base end portion which is flatly crushed.

In the small fluorescent tube having the cold cathode type electrode 21 as described above, the rare gas sealed in the sealing body 11 is preferably one containing argon and neon as main components, and particularly, The ratio of neon in all rare gases is 4
It is preferably from 0 to 97 mol%. Further, it is preferable that the rare gas filling pressure is 40 to 100 Torr.
By satisfying such conditions, a small fluorescent tube having a low starting voltage and a high luminance can be obtained.

In the small fluorescent tube of the present invention, an excess of 1.1 to 2.0 times the input power during steady lighting of the small fluorescent tube is set for a set time in the range of 10 to 60 seconds after the start of lighting. It is preferable that the light is turned on by supplying electric power. In this way, by supplying excess power for a specific time after the start of lighting, the rise time of the brightness of the small fluorescent tube becomes extremely short.

When the amount of excess power is less than 1.1 times the input power during steady lighting of the small fluorescent tube, the desired effect can be sufficiently obtained even if the excess power supply time is extended. I can't. On the other hand, when it exceeds 2.0 times, the electric current corresponding to the amount of supplied electric power cannot be passed through the small fluorescent tube 20, so that not only the power is wasted but also the useful life of the small fluorescent tube is increased. May be shortened, which is not preferable.

If the excess power supply time is shorter than 10 seconds, the desired effect cannot be sufficiently obtained even if the excess power amount is increased. On the other hand, if the length of the excessive power supply time exceeds 60 seconds, not only is the power wasted wastefully, but the service life of the small fluorescent tube may be shortened, which is not preferable.

FIG. 3 is an explanatory view showing the structure of an example of the small fluorescent tube device of the present invention. This small fluorescent tube device is a small fluorescent tube 10 having the structure shown in FIG. It is composed of a pair of holding members 30 provided to hold both ends of the envelope 11.

As shown in FIG. 4, each of the holding members 30 has a U shape, and the distance between the two inner wall surfaces 31 and 33 facing each other is determined by the small fluorescent tube 10. The diameter is equal to or slightly smaller than the outer diameter of the sealing body 11. The envelope 11 of the small fluorescent tube 10 has an outer surface and three inner wall surfaces 3 of the holding member 30.
It is held by the holding member 30 in a state of point contact with each of 1, 32, and 33.

As a material for the holding member 30, for example, a resin material having heat resistance such as polycarbonate or phenol resin can be used.

As described above, when the small fluorescent tube 10 having the hot cathode type electrode 14 including the metal sleeve 15 and the filament 16 is used, the holding member 30 has both ends T1 in the sealing body 11 of the small fluorescent tube 10. Is provided at a position T2 of 5 mm from the inside to the inside of the position T2, or preferably at a region between the position T2 and a position T3 of 15 mm from the both ends T1 toward the inside.

FIG. 5 is a curve diagram showing the relationship between the distance from the end of the envelope 11 of the small fluorescent tube 10 and the temperature of the tube wall. As is clear from this figure, in the small fluorescent tube 10 having the hot-cathode type electrode 14, the coldest wall temperature is the lowest in the region from the end of the envelope 11 to 5 mm inward. It is understood that there are dots.

According to the above-mentioned small fluorescent tube device,
Since the holding member 30 is provided in a region other than the region where the coldest spot where the tube wall temperature is lowest in the envelope 11 of the small fluorescent tube 10, that is, the region where the tube wall temperature is high, heat is applied to the holding member 30. Even if deprived, the influence on the temperature rise in the envelope 11 is extremely small, and as a result, the rise time of the luminance can be shortened.

In the above-mentioned small fluorescent tube device, the inside of the envelope 11 of the small fluorescent tube 10 is moved inward from both ends by five.
It is preferable that an attachment member such as a mouthpiece and other peripheral members are not provided in contact with the region outside the position of mm, so that the effects of the present invention can be reliably achieved.

FIG. 6 is an explanatory view showing the structure of another example of the small fluorescent tube device of the present invention. This small fluorescent tube device is a small fluorescent tube 20 having the structure shown in FIG. It is composed of a pair of holding members 30 having the structure shown in FIG.

As described above, when the small fluorescent tube 20 having the cold cathode type electrode 21 made of the metal sleeve is used, the holding member 30 is composed of the both ends T1 of the sealing body 11 of the small fluorescent tube 20 and the both ends T1. It is provided in an area between the position T2 and 5 mm toward the inside.

FIG. 7 is a curve diagram showing the relationship between the distance from the end of the envelope 11 of the small fluorescent tube 20 and the temperature of the tube wall. As is clear from this figure, in the small fluorescent tube 20 having the cold cathode type electrode 21, the region inside the position of 5 mm from the end of the envelope 11 to the inside,
It is understood that there is a coldest spot with the lowest tube wall temperature.

According to the above small fluorescent tube device,
Since the holding member 30 is provided in a region other than the region where the coldest spot where the tube wall temperature is lowest in the envelope 11 of the small fluorescent tube 20, that is, the region where the tube wall temperature is high, heat is applied to the holding member 30. Even if deprived, the influence on the temperature rise in the envelope 11 is extremely small, and as a result, the rise time of the luminance can be shortened.

[0035]

[Enclosure (11)]

Material: Lead glass, Dimensions: Overall length 160mm, outer diameter 3.15mm, inner diameter 2.3
5 mm (Section area S = 3.45 × 10 ⁻⁶ m ² ) [Lead wire (13)] Material: Dumet wire, outer diameter 0.35 mm [Electrode (14)] Metal sleeve (15): Material; stainless steel, dimensions Total length 4 mm, outer diameter 1.4 mm, inner diameter 1.2 mm Filament (16): material; tungsten, wire diameter 3
0 μm, emitter material; (Ba, Sr, Ca) O [phosphor layer (17)] Material: three-wavelength phosphor, thickness: 15 μm [encapsulation] Encapsulation gas: mixed gas of argon and krypton (composition ratio: argon / Krypton = 90 mol% / 10 mol%), filling pressure: 50 Torr, mercury: filling amount 2 mg

When the small fluorescent tube (10) was lit by high frequency power of 40 kHz, the initial characteristics during steady lighting were as follows: rated lamp current 20 mA, rated lamp voltage 150 V, input power 3 W (unit of sealed body). The input power per length P = 17 W / m) and the ratio S / P value was 0.20 × 10 ⁻⁶ . Further, in the above small fluorescent tube (10), chromaticity x = 0.29, y =
Initial saturation brightness at 0.27 was 45,000 cd / m ²
Met.

Encapsulation body (11) for the above-mentioned small fluorescent tube (10)
A small fluorescent tube device having the structure shown in FIG. 3 was produced by providing the holding members (30) at positions 10 mm inward from both ends of each.

<Examples 2 and 3 and Comparative Example 1> Table 1 below.
A small fluorescent tube was manufactured according to the conditions described in 1. and a small fluorescent tube device was manufactured in the same manner as in Example 1 except that these small fluorescent tubes were used. In addition, 40kH of these small fluorescent tubes
Table 1 shows the initial characteristics at the time of steady lighting by the high frequency power of z.

[0039]

[Table 1]

Example 4 A small fluorescent tube (20) was manufactured under the following conditions according to the structure of FIG. [Encapsulation body (11)] Material: lead glass, dimensions: total length 160 mm, outer diameter 2.60 mm, inner diameter 2.0
mm (Cross-sectional area S = 2.17 × 10 ⁻⁶ m ² ) [Lead wire (13)] Material: Dumet wire, outer diameter 0.35 mm [Electrode (21)] Material: stainless steel, dimensions: total length 4 mm, outer diameter 1.4m
m, inner diameter 1.2 mm [phosphor layer (17)] Material: three-wavelength phosphor, thickness: 15 μm [encapsulation] Encapsulation gas: mixed gas of neon and argon (composition ratio:
Neon / argon = 95 mol% / 5 mol%), filling pressure:
80 Torr, Mercury: Encapsulated amount 2 mg

When the small fluorescent tube (20) was lit with a high frequency power of 40 kHz, the initial characteristics during steady lighting were: rated lamp current 5 mA, rated lamp voltage 360 V, input power 1.8 W (encapsulation). Input power per unit length P = 8.25 W / m), and the value of the ratio S / P was 0.26 × 10 ⁻⁶ . In the above small fluorescent tube (20), chromaticity x = 0.29, y =
The initial saturated brightness at 0.27 was 26,000 cd / m ²
Met.

Encapsulation body (11) for the above-mentioned small fluorescent tube (20)
The small fluorescent tube device having the structure shown in FIG. 4 was manufactured by providing the holding members (30) at positions 5 mm inward from both ends in FIG.

<Examples 5 and 6 and Comparative Example 2> Table 1 below.
A small fluorescent tube was manufactured according to the conditions described in 1. and a small fluorescent tube device was manufactured in the same manner as in Example 1 except that these small fluorescent tubes were used. In addition, 40kH of these small fluorescent tubes
Table 1 shows the initial characteristics at the time of steady lighting by the high frequency power of z.

[0044]

[Table 2]

<Measurement of Luminance Rising Time> Using the small fluorescent tube devices according to the above Examples 1 to 6 and Comparative Examples 1 and 2, under the environment of a temperature of 25 ° C., the following lighting conditions (1) and ( 2) turn on the small fluorescent tube,
The luminance from the start of lighting was measured with time, and the saturated luminance was 90%.
The time to reach a brightness of% was measured. Lighting condition (1): Power equal to the input power during steady lighting is supplied. Lighting condition (2): 1.5 times the input power during steady lighting is supplied for 20 seconds. The results are shown in Table 3.

[0046]

[Table 3]

As is apparent from Table 3, the small fluorescent tubes according to Examples 1 to 3 have a shorter rise time of luminance than the small fluorescent tubes according to Comparative Example 1. The small fluorescent tubes according to Nos. 4 to 6 had a shorter rise time of luminance than the small fluorescent tubes according to Comparative Example 2. Moreover, it was confirmed that the rise time of the luminance was further shortened by supplying the electric power 1.5 times the input electric power during the steady lighting for 20 seconds.

[0048]

As described above, according to the small fluorescent tube of the present invention, the value of the ratio S / P of the cross-sectional area S of the envelope and the input power P per unit length of the envelope is specified. Because it is in range
The rise time of brightness can be shortened.

According to the small fluorescent tube device of the present invention,
Since the holding member is provided in the region where the tube wall temperature in the envelope is high, even if heat is taken by the holding member, the influence on the rise in temperature inside the envelope is extremely small, and as a result, the rise time of luminance is shortened. can do.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing a configuration of an example of a small fluorescent tube of the present invention.

FIG. 2 is an explanatory cross-sectional view showing the configuration of another example of the small fluorescent tube of the present invention.

FIG. 3 is an explanatory sectional view showing a configuration of an example of a small fluorescent tube device of the present invention.

FIG. 4 is an explanatory view showing an example of a holding member.

5 is a curve diagram showing the relationship between the distance from the end and the tube wall temperature in the envelope of the small fluorescent tube having the configuration shown in FIG.

FIG. 6 is an explanatory cross-sectional view showing the configuration of another example of the small fluorescent tube device of the present invention.

FIG. 7 is a curve diagram showing the relationship between the distance from the end and the tube wall temperature in the envelope of the small fluorescent tube having the configuration shown in FIG.

[Explanation of symbols]

 10 Small Fluorescent Tube 11 Encapsulant 12 Sealing Part 13 Lead Wire 14 Electrode 15 Metal Sleeve 16 Filament 17 Fluorescent Layer 20 Small Fluorescent Tube 21 Electrode 30 Holding Member 31, 32, 33 Inner Wall Surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiichi Matsumoto, 1194 Sado, Bessho-cho, Himeji-shi, Hyogo Prefecture Ushio Electric Co., Ltd. (72) Inventor, Makoto Fujii 1194, Sado, Bessho-cho, Himeji-shi, Hyogo Ushio Electric Co., Ltd. (72) Inventor Akiko Hatake 1194 Sado, Bessho-cho, Himeji City, Hyogo Prefecture Ushio Electric Co., Ltd.

Claims (4)

[Claims] 1. A small fluorescent tube comprising a tubular envelope having an inner diameter of 5 mm or less, and a pair of electrodes arranged in the envelope so as to face each other. A small fluorescent tube characterized in that the value of the ratio S / P between (m ² ) and the input power P (W / m) per unit length of the envelope satisfies the following condition. Condition 0.05 × 10 ^-6 ≦ S / P ≦ 0.45 × 10 ^-6 2. The input power of 1.1 to 2 ... of the input power during steady lighting for a set time in the range of 10 to 60 seconds after the start of lighting.
The small fluorescent tube according to claim 1, wherein the small fluorescent tube is turned on by supplying 0 times excess power. 3. The small fluorescent tube according to claim 1 or 2, and a holding member provided to hold the sealed body of the small fluorescent tube, wherein each of the electrodes of the small fluorescent tube is The holding member comprises a metal sleeve and a filament arranged so as to be housed in the cylindrical hole of the metal sleeve, and the holding member is located at a position of 5 mm from the both ends of the sealing body of the small fluorescent tube to the inside or inside thereof. The small fluorescent tube device is provided in the area of. 4. The small fluorescent tube according to claim 1 or 2, and a holding member provided to hold the sealed body of the small fluorescent tube, wherein each of the electrodes of the small fluorescent tube comprises: A small fluorescent tube comprising a metal sleeve or a metal rod, and the holding member is provided in a region between both ends of the sealed body of the small fluorescent tube and a position 5 mm inward from the both ends. apparatus.