JPH08102284A - Low-pressure discharge lamp and discharge lamp device - Google Patents

Abstract

PURPOSE: To improve the starting characteristic and the maintenance of a lamp, and to prolong the lifetime of the lamp by effectively combine core diameter and coil pitch or the like so as to prevent the lowering of coil resistance value by winding a primary coil around a core, and stabilizing the negative electrode spot temperature. CONSTITUTION: An electrode is connected to lead wires 8, 8 arranged in a stem formed of a triple coil filament 7, which is obtained by winding a tungsten wire 70 triple, by a means such as crimping. In this filament 7, a primary coil 71 is formed by winding a tungsten wire 70, which is obtained by adhering a core 80 made of molybdenum and a narrow core 80 made of tungsten wire 81 onto parallel lines. The primary coil 71 is wound around a secondary core 82 so as to form a secondary coil 72. At this stage, the secondary coil 72 is wound around a tertiary coil, which is not showed with a figure, and the cores 80, 82 are eliminated and the core 81 is left so as to form the filament 7. Electron emitting material 9E made of the oxide of Ba, Sr, Ca is adhered for carrying to a space between pitches of the coil. Negative electrode spot temperature is thereby stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil filament used as an electrode of a compact fluorescent lamp.

[0002]

2. Description of the Related Art Since a fluorescent lamp is superior in light efficiency to a general incandescent lamp and can be used with low electric power and has a long life, an E26 type screw-in type which is generally used for an incandescent lamp in a fluorescent lamp. A lamp called a normal fluorescent lamp, which is compatible with incandescent light bulbs that can be attached to an existing socket as it is and has a lighting circuit component such as a ballast installed, has been commercialized. ing.

In this bulb-type fluorescent lamp equipped with an E26 type base, a tube-shaped glass bulb having discharge electrodes sealed at both ends is bent into a substantially U-shape, or the U-shaped bulb is curved again into a substantially U-shape. As a so-called saddle-shaped curved tube bulb, it is made as compact as possible to form a fluorescent lamp bulb, or a plurality of straight tube glass bulbs are formed in a substantially U shape or a W shape through a connecting pipe. Forming a valve. Then, the fluorescent lamp bulb and the lighting circuit parts are mounted on a cover member to be integrated, and the fluorescent lamp bulb is covered with a glove member if necessary, and a screw-type base is attached to the cover member for regular use. It is configured so that it can be attached to a socket for an incandescent light bulb.

As in the conventional straight tube type fluorescent lamp, this light bulb type fluorescent lamp also uses a hot cathode composed of a coil filament in which a tungsten wire is wound in a double or triple. . Further, in order to make the lamp compact, this type of bulb-type fluorescent lamp is used by bending a thin glass bulb having an outer diameter of about 10 to 20 mm. In addition, as the diameter of the bulb becomes smaller, it is not possible to use a coil filament with the same lamp current value as that used in a straight tube lamp as the electrode.If the length is not shortened, the end of the electrode will be the inner surface of the bulb. When the bulb is covered with an electrode, the fluorescent material coating on the inner surface of the bulb may be peeled off or the inner surface of the bulb may be damaged, resulting in poor appearance. There is a problem that the coil is stretched by catching it, or the valve is sealed while being tilted, and a perfect failure occurs such as not having a predetermined characteristic or forming a hole in the sealing portion.

Therefore, as a measure against such a problem, the member size of the tungsten wire and the coil size are regulated. Such a thing is described in, for example, Japanese Patent Publication No. 5-56620. The lamp described in this publication has a lamp current of 120 to 250 mA, has a triple-wound coil filament with an air core inside the primary coil, and defines the tungsten wire diameter and the number of turns of the secondary coil. . With this structure, the cold resistance of the coil filament is increased to improve the starting characteristics, and at the same time, the ability to retain the electron emissive substance is increased to prolong the service life.

Therefore, for a lamp having a lamp current of 250 mA or more, a triple coil filament having an air core in the primary coil was prototyped based on the description of the above publication, and a lamp was manufactured using this coil filament to investigate the characteristics. This prototype lamp also has a long life on average because the cold resistance of the coil filament can be increased and the starting characteristics are improved, and the amount of electron emissive material retained can be increased.

However, although the triple coil filament can increase the cold resistance and the starting characteristic is certainly improved, the coil has a slack called sag. This sag is a slack that occurs when the coil filament is heated by energization, and the coil filament wound with a tungsten wire is deformed, making the cathode spot (bright spot) temperature unstable, and the luminous efficiency and life characteristics of the lamp. Caused variations.

This is because the lamp current described in the publication is 120 to 2
With a relatively low current of 50 mA, because the tungsten wire used is thin and the weight of the coil filament is relatively light, there is little sag in the coil and there is no core wire in the primary coil. It may be able to withstand shock and vibration.

If the core wire is not inserted in the coil,
Degradation and activation of electron emissive material during lighting may be difficult because the temperature becomes low.

Generally, when a core wire is inserted in the coil, the resistance value of the coil is lowered and the temperature rise is slow immediately after the start of energization, so that the starting characteristic is deteriorated. A triple-wound coil filament that does not have a core wire in the primary coil like the lamp described in this publication can increase the cold resistance of the coil filament and certainly improve the starting characteristics.
Sag called sag occurs in the coil filament. This sag is a slack that occurs when the coil filament is heated by energization, and the coil filament is deformed, making the cathode spot (bright spot) temperature unstable.
This is a factor that causes variations in the luminous efficiency and life characteristics of the lamp.

[0011]

According to the present invention, the temperature of the cathode spot (bright spot) can be stabilized, the sag of the coil filament can be reduced, and the variation in the starting characteristics and the life characteristics can be kept small. The lamp current is 250 mA or more. It is an object of the present invention to provide a low pressure discharge lamp having a relatively large output.

[0012]

A low-pressure discharge lamp according to claim 1 of the present invention is provided with a glass bulb, a discharge medium enclosed in the glass bulb, and both ends of the glass bulb. It is characterized by comprising a triple coil filament made of a tungsten wire having a coil dimension and an electron emissive material deposited on this coil filament, and as the coil dimension, 250 mA ≤ rated lamp current IL ≤ 350 m
A, and FD1, MD1, P1, MD2, P at this time
2, MD3, P3 value (mm) Is a value that satisfies the following, and from that value (mm), FD1, MD1,
± 20% for P1, MD2, P2, MD3 and P3 respectively
Within the deviation range of.

In the above, FD1: tungsten wire diameter, MD1: primary core wire diameter, P1: primary coil pitch, MD2: secondary core wire diameter, P2: secondary coil pitch, MD3: tertiary core wire diameter, P3: tertiary coil. pitch,
Is.

The low-pressure discharge lamp according to claim 2 of the present invention is characterized in that the inner diameter of the glass bulb is 9 to 16 mm.

The low-pressure discharge lamp according to claim 3 of the present invention is characterized in that the glass bulb has an outer shape of a straight tube or a bent tube.

The low-pressure discharge lamp according to claim 4 of the present invention is characterized in that a phosphor coating is formed on the inner surface of the glass bulb.

A discharge lamp device according to a fifth aspect of the present invention is a holder, a lighting circuit device attached to the holder, the lighting circuit device being connected to the lighting circuit device, and being held by the holder. The low pressure discharge lamp according to any one of claims 1 to 4 and a cover member which covers the lighting circuit device and the holder and is provided with a base.

The discharge lamp device according to claim 6 of the present invention is the lighting circuit device, a socket connected to the lighting circuit device, and any one of the above claims 1 to 4 mounted in the socket. The low-pressure discharge lamp described above is provided.

[0019]

[Function] By controlling the relationship between the core wire diameter ratio of the coil filament and the dimensions of each part of the coil within the optimum range, the coil temperature rises immediately after the start of energization, the starting characteristics and life characteristics can be secured, and the core wire is contained in the coil. Because of its high strength, it is strong against vibration and shock as well as sagging.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a light bulb-shaped fluorescent lamp L. In FIG. 1, reference numeral 1 denotes a saddle-shaped non-linear fluorescent lamp bulb in which a glass tube is bent twice in a U shape, and electrodes (described later) are provided at both ends of the bulb 1. And a phosphor coating (not shown) is formed on the inner surface. Reference numeral 2 denotes a holder for holding the bulb 1, to which a lighting circuit device including circuit components (not shown) including a ballast 3 is attached. 4A
Is a plurality of ventilation holes 4h, 4h covering the upper part of the holder 2.
A cover member made of an opaque synthetic resin on which h, ... Are formed,
4B is a silicon adhesive 5 on the opening of the cover member 4A.
A substantially spherical translucent globe made of glass or synthetic resin covering the fluorescent lamp bulb 1 joined via A, and an envelope 4 is constituted by both 4A and 4B. Further, 6 is a base attached to one end of the cover member.

The holder 2 has a cylindrical fixing portion 2
The end portion 1A of the bulb 1 is inserted into A, and the fluorescent lamp bulb 1 is held by being fixed by an adhesive 5B. The ballast 3 is mounted in a mounting frame, and has a protrusion (not shown) for mounting the cap, which has a threaded portion on the outside through the support arm 2B. In addition, reference numeral 9 in the drawing denotes a light diffusion film formed as necessary.

As shown in FIGS. 2 (a) and 2 (b), the electrode is composed of a triple coil filament 7 in which a tungsten wire 70 is triple wound, and caulked to lead wires 8 and 8 implanted in the stem. Is connected by the means of.

The triple coil filament 7 constituting this electrode has a thick core wire 8 made of, for example, molybdenum.
0 and a fine core wire 81 made of a tungsten wire are closely contacted on a parallel straight line, and the tungsten wire 70 is wound to form a substantially oval primary coil 71. Then, as shown in FIG. 3, the primary coil 71 is wound around a secondary core wire 82 to form a secondary coil 72. Further, the secondary coil 72 is wound around a tertiary core wire (not shown), and one of the primary core wires 81 is left, and the other core wires 80 and 82 (including the tertiary core wire (not shown)) are pulled out or mixed acid. The triple coil filament 7 shown in FIG. 4 is formed by immersing it in a liquid and removing it. Reference numeral 74 is a leg portion at the end portion of the triple coil filament 7 in the state of the secondary coil 72, and the leg portions 74, 74 are connected to the lead wires 8, 8.

The portion of the triple coil filament 7 which is covered with the secondary coil 72, except for the core wire 81 portion remaining inside the primary coil 71, has a substantially oval shape and a portion between the coil pitches. An electron emissive substance 9E made of an oxide of barium Ba, strontium Sr, and calcium Ca was adhered and supported in the space of.
The amount of the electron emissive material 9E carried on the secondary coil 72 is about 0.3 mg. During the above-mentioned application, the electron emissive material 9E flows and does not adhere to the coil 73 of the third coil 73 having a large number of winding turns and a large pitch interval. (FIG. 5 shows a part of the secondary coil 72 in an enlarged scale.) The application of the electron emissive material 9E is performed by immersing the triple coil filament 7 in a carbonate solution of the electron emissive material to form the primary core wire 81. Primary coil 71 (within winding turns and between pitches) and secondary coil 72 where
The electron-emissive substance 9E is applied and dried by utilizing the capillary phenomenon in the voids formed in (in the winding turns and between the pitches). Then, in the evacuation process of the lamp L, the triple coil filament 7 which is an electrode is heated by high frequency or the like to decompose the electron emissive substance 9E deposited on the coil filament 7 to be an oxide. For example, when the lamp L having such a structure is attached to a luminaire in a general household and is energized, a predetermined light is emitted from the globe 4B portion for normal illumination.

More specifically, when the lamp L is preheated by energizing the triple coil filament 7 which is a hot electrode, thermoelectrons are emitted from the electron emissive material 9E carried on the coil filament 7 into the bulb 1. The thermoelectrons are attracted and moved by the high voltage of the triple coil filament 7 on the opposite side to start arc discharge. Electrons flowing by this discharge collide with mercury atoms in the bulb 1 to generate ultraviolet rays,
The ultraviolet rays excite the phosphor coating applied to the inner surface of the bulb 1 to emit visible light, which is emitted from the outer surface of the bulb 1.

The starting point of this discharge (cathode spot (bright spot)) is from the end of the electron emitting substance 9E in the triple coil filament 7 which is a hot cathode, and this cathode spot (bright spot) is of the electron emitting substance 9E. It moves with the scattering. When the electron emissive material 9E is scattered and consumed, the coil filaments 7,
It becomes difficult to radiate sufficient electrons during 7 seconds, and it becomes impossible to maintain the arc discharge, so that the lamp L is extinguished and the life is exhausted.

However, the lamp 1 can carry a larger amount of electron emissive material 9E than the conventional lamp by adjusting the dimensions of the primary coil 71 and the secondary coil 72 as compared with the conventional lamp. If the inner diameter and pitch of the secondary coil 72 and the core wire 81 in the primary coil 71 have the above-described dimensions, the solution of the electron emissive material 9E easily enters the coils 72, 71, and after the firing, the solution becomes a lump. Can be firmly supported without dropping from between the pitches.

Further, since the core wire 81 is inserted in the primary coil 71, the degree of sag generated in the coil 7 at the time of lighting is small, and the deflection or pitch unevenness due to the deformation of the coil 7 is slight, so that the cathode spot (brightness) can be obtained. 10) The optimum temperature
As a result, it was possible to secure a temperature of 50 ° C. or less, and it was possible to reduce variations in the luminous efficiency and life characteristics of the lamp.

The present inventor has found that the lamp current is 250 m.
As a result of various studies on the triple coil filament used for the lamp of A to 350 mA, the inner diameter (m of the secondary coil 72 portion that affects the following numerical range and characteristics (m
m), pitch (mm), and core wire diameter (mm) inserted in the primary coil 71, it was found from FIG. 6 plotted in a three-dimensional space that the coil data of a desired lamp current can be extracted.

0.022 mm ≤ tungsten wire outer diameter (FD1) ≤ 0.035 mm, 0.06 mm ≤ primary coil 71 inner diameter (MD1) ≤ 0.1 mm, 0.064 mm ≤ primary coil 71 pitch (P1) ≦ 0.096 mm, 0.2 mm ≦ Inner diameter of secondary coil 72 (MD2) ≦ 0.35 mm, 0.2 mm ≦ Pitch of secondary coil 72 (P2) ≦ 0.35 mm, 0.72 mm ≦ Inner diameter of tertiary coil 7 (MD3) ≤ 1.1 mm, 0.63 mm ≤ Pitch of secondary coil 7 (P3) ≤ 1.3 mm, and here, the inner diameter of the coil = outer diameter of the core wire.

On the straight line connecting points A and B in FIG. 6, deviation from this line was acceptable as long as the deviation from the line center was within 20%.

The point A in FIG. 6 is the lamp current 2
At the lower limit of 50 mA, below this value, the electron emissive material is less likely to enter the coil, resulting in poor electron emissivity and a short lamp life. However, the temperature of the coil rises and the starting characteristics are improved. The point B is the upper limit value when the lamp current is 350 mA. Above this point, the electron emissive substance easily enters the coil, but the retention function of the electron emissive substance is poor and the lamp has a short life. At the same time, the temperature of the coil rises and the starting characteristics deteriorate.

From the above and in consideration of FIG. 6, the dimension of the triple coil filament used in the lamp having the lamp current IL of 250 mA to 350 mA may be within the range derived from the following equation.

FD1, MD1, P1, MD at this time
2, the value (mm) of P2, MD3, P3 is Within the range that satisfies, and the deviation is allowed up to ± 20%.

When the tungsten wire outer diameter (FD1) is less than 0.022 mm, the wire becomes thin and the spot (bright spot) temperature becomes too high, and the strength is weak and the number of wire breaks in the coiling process increases. Also, 0.035 mm
If it exceeds, the spot (bright spot) temperature will be too low and the electron emissive substance will not easily adhere.

When the inner diameter (MD1) of the primary coil 71 is less than 0.06 mm, the spot (bright spot) temperature becomes too high and the electron emissive substance is hard to adhere. If it exceeds 0.1 mm, the temperature of the spot (bright spot) becomes too low and the primary core wire is deformed, and the tungsten wire is easily broken.

When the pitch (P1) of the primary coil 71 is less than 0.064 mm, the spot (bright spot) temperature becomes too high and the electron emissive substance becomes difficult to adhere. Also, if it exceeds 0.096 mm, it is a spot (bright spot).
If the temperature becomes too low and the electron emissive material is deposited, it will flow down.

If the inner diameter (MD2) of the secondary coil 72 is less than 0.2 mm, the spot (bright spot) temperature becomes too high, and the amount of the electron emissive substance attached decreases. Further, if it exceeds 0.35 mm, the spot (bright spot) temperature becomes too low, and it becomes difficult for the electron emissive substance to be activated to the inside.

When the pitch (P2) of the secondary coil 72 is less than 0.2 mm, the spot (bright spot) temperature becomes too high and the electron emissive substance is hard to adhere.
On the other hand, if it exceeds 0.096 mm, the spot (bright spot) temperature becomes too low, and the electron emissive substance flows down when deposited.

If the inner diameter (MD3) of the tertiary coil 7 is less than 0.72 mm, the spot (bright spot) temperature becomes too high. Further, if it exceeds 1.1 mm, the spot (bright spot) temperature becomes too low and the coils are easily entangled with each other, which makes it difficult to perform the wire connection work.

Further, if the pitch (P3) of the tertiary coil 7 is less than 0.63 mm, the spot (bright spot) temperature becomes too high. Further, if it exceeds 1.30 mm, the spot (bright spot) temperature becomes too low, and the number of windings becomes small, so that the amount of the electron emissive substance deposited becomes small.

In some cases, it is preferable to keep the content within the above range.

The inner diameter (mm) and pitch (mm) of the secondary coil 72 and the diameter (mm) of the core wire inserted in the primary coil 71 are the starting voltage (Vs) and the amount of the electron emissive substance deposited (mg). ) Is shown in FIGS. 7 and 8. These figures may be appropriately determined according to the specifications.

The length of the tertiary coil 7 (only the triple coil portion) is in contact with the opening of the valve, and is preferably 3 mm or less.

The inner diameter of the valve is applicable to the range of 9 to 16 mm.

Further, according to the results of the trial production by the present inventor of various bulb-shaped fluorescent lamps L having the same shape as the above-mentioned embodiment and a lamp current of 250 to 350 mA, the triple coil filament constituting the hot cathode has the above numerical values. Within the range satisfying the conditions, the spot (bright spot) temperature could be maintained at 1050 ° C. or lower, which was good as in the above example.

Further, according to the present invention, a larger amount of electron emissive material can be carried than the coil filament of the conventional lamp, and since the core wire is put in the primary coil, the degree of sag generated in the coil during lighting. It is also lighter, and the deflection and pitch unevenness due to the deformation of the coil filament are minimal, making the cathode spot (bright spot) temperature unstable and reducing variations in lamp starting characteristics, luminous efficiency and life characteristics. .

The present invention is not limited to the above embodiment. For example, the lamp is not limited to the bulb-shaped fluorescent lamp, but E
A lamp in which a bulb without a die base is bent into a U shape, a W shape, a ring shape or the like may be of course a straight tube shape, and the type is not limited to a fluorescent lamp and may be a lamp for ultraviolet radiation or the like. Further, the present invention can be applied to other low-pressure discharge lamps such as a lamp that emits a rare gas without enclosing mercury in the bulb.

The coil constituting the hot cathode, of course, varies depending on the lamp current, and the filament wire outer diameter and the coil length, inner diameter, winding number, pitch and other constituent dimensions may be appropriately determined.

Further, the electron emissive substance held in the coil is not limited to (Ba, Ca, Sr) O described above, but may be Ba.
-MO (M; Ta, Al, V, W, Ti), Ba-C
a-M-O (M; Ta, Al, V, W, Ti), etc., or a combination thereof or Al ₂ O ₃ , ZrO ₂ ,
For example, a small amount of Sr ₂ O ₃ may be added.

The fluorescent lamp L of the present invention is used in a lighting fixture D which is a discharge lamp device as shown in FIG.
In FIG. 9, the fluorescent lamp L is mounted and turned on in the sockets S and S attached to the housing such as the reflector R. C in the figure
Is a case containing a lighting circuit device such as a ballast.

[0052]

As described in detail above, according to the present invention, it is possible to optimize the reduction of the coil resistance value by inserting the core wire into the primary coil by improving the combination of the core wire diameter and the coil pitch. By stabilizing the cathode spot (bright spot) temperature, it was possible to maintain and improve the starting characteristics of the lamp and extend its life. Further, by inserting a core wire into the primary coil to prevent sagging of the coil, variations in light emission characteristics and life characteristics due to coil deformation are reduced, and coil strength against vibration and shock is improved.

Therefore, it is possible to provide a low-pressure discharge lamp which has little variation in light emission characteristics, starting characteristics, and life characteristics, has stable lighting characteristics for a long period of time, and is resistant to vibration and shock.

[Brief description of drawings]

FIG. 1 is a partially sectional front view showing an embodiment of a light bulb shaped fluorescent lamp of the present invention.

2 is an enlarged view showing a part of a primary coil in a manufacturing process of a triple coil used in the lamp of FIG. 1, FIG. 2 (a) is a side sectional view, and FIG. 2 (b) is a front view. It is a figure.

FIG. 3 is a front cross-sectional view showing an enlarged part of the secondary coil during the manufacturing process of the triple coil used in the lamp of FIG.

4 is a partial sectional front view showing a triple coil used in the lamp of FIG. 1. FIG.

5 is a front view showing a part of the triple coil of FIG. 4 in an enlarged manner. FIG.

FIG. 6 Inner diameter of secondary coil (mm), pitch of secondary coil (mm) and outer diameter of core wire contained in primary coil (mm)
It is a graph which shows and compares the relationship with.

FIG. 7: Inner diameter of secondary coil (mm), pitch of secondary coil (mm), and outer diameter of core wire contained in primary coil (mm)
5 is a graph showing the starting voltage (Vs) of the.

FIG. 8: Inner diameter of secondary coil (mm), pitch of secondary coil (mm), and outer diameter of core wire contained in primary coil (mm)
3 is a graph showing the amount of the electron radioactive substance attached.

FIG. 9 is a perspective view showing an embodiment of a discharge lamp device of the present invention.

[Explanation of symbols]

 L: Lamp (bulb-shaped fluorescent lamp) 1: Glass bulb 4A: Cover member 4B: Globe 6: Base 7: Triple (triple) coil 70: Filament wire 71: Primary coil 72: Secondary coil 81: Core wire 9E: Electron emission material

Claims (6)

[Claims] 1. A glass bulb; a discharge medium sealed in the glass bulb; a triple coil filament provided at both ends of the glass bulb and made of a tungsten wire having the following coil dimensions; A low-pressure discharge lamp, characterized in that it comprises: As the coil dimension, 250 mA ≤ rated lamp current IL ≤ 350 m
A, and FD1, MD1, P1, MD2, P at this time
2, MD3, P3 value (mm) Is a value that satisfies the following, and from that value (mm), FD1, MD1,
± 20% for P1, MD2, P2, MD3 and P3 respectively
Within the deviation range of. In the above, FD1: tungsten wire diameter, MD1: primary core wire diameter, P1: primary coil pitch, MD2: secondary core wire diameter, P2: secondary coil pitch, MD3: tertiary core wire diameter, P3: tertiary coil pitch,
Is. 2. The inner diameter of the glass bulb is 9 to 16 mm
The low-pressure discharge lamp according to claim 1, wherein 3. The glass bulb according to claim 1, wherein the glass bulb has a straight tubular shape or a curved tubular shape.
Low-pressure discharge lamp described in. 4. The low-pressure discharge lamp according to claim 1, wherein a phosphor coating is formed on the inner surface of the glass bulb. 5. A low-voltage discharge according to claim 1, further comprising: a holder; a lighting circuit device attached to the holder; connected to the lighting circuit device and held by the holder. A discharge lamp device comprising: a lamp; and a cover member that covers the lighting circuit device and the holder and is provided with a base. 6. A lighting circuit device; a socket connected to the lighting circuit device; and the low-pressure discharge lamp according to any one of claims 1 to 4 mounted in the socket. Characteristic discharge lamp device.