JPH03210758A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To reduce starting voltage by making the length of at least one discharge route shorter than of the other ones. CONSTITUTION:The length of a partition 3' of a discharge route 4R is defined as shorter than that of partitions 3 of the other discharge routes 4C, 4B, 4G. An interval between an anode electrode 7R and a common cathode electrode 10 can be made shorter thereby, and the discharge starting voltage of the discharge route 4R is thus reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent lamp mainly used as a display element in large color display devices and the like.

[Prior Art 1] As a fluorescent lamp used for a display element of a large color display device, the present inventors proposed a fluorescent lamp having an integrated discharge space structure as shown in FIG. This fluorescent lamp has one common cathode 10 and four anodes 7 *t 7 Cy 7
R* 7 C, the common electrode 10 is housed in an electrode chamber, and one end of each discharge path R14 communicates with the electrode chamber.
Cl 4 B* 4 C is formed into branches, and each anode electrode 7 is arranged at the other end of each discharge path 4 . Note that, strictly speaking, the discharge path includes the electrode chamber portion, but in the following explanation, only the portion branched for each anode electrode 7 will be referred to as the discharge path. In this fluorescent lamp, by applying a high voltage between each anode electrode 7 and the common cathode 10, each discharge path 4 emits light, and by independently controlling the voltage applied to each anode electrode 7. It is possible to perform dimming lighting in any step.

More specifically, this fluorescent lamp has a box-shaped base 1 with an open top and made of a non-transparent material with a relatively high visible light reflectance, such as ceramic, and a cross-shaped partition wall 2 inside the base 1. The interior of the base 1 is divided into four sections, and a transparent glass plate 8 is attached to the upper surface of the base 1 to form each discharge path 4. Here, a particicon 3 is formed in each discharge path 4 in order to lengthen the discharge path 4 and increase lamp efficiency.

The inner surface of each discharge path 4 is coated with a phosphor that emits light of each color, so that the upper surface of the base 1 covered with the glass plate 8 serves as a light emitting surface. The lower surface of the base 1 has an open upper surface and a common cathode 1 from the inner bottom surface.
The stem 9 supporting the 0 is integrally provided in a protruding manner, and the lath pulp 11 is covered with the lath pulp 11, and the inside of the lath pulp 11 becomes an electrode chamber.

A discharge hole 6 R* 6 Gt 6 is provided at one end of each discharge path 4.
By 6 C is formed, and each discharge path 4 is formed by this discharge hole 6.
is communicated with the electrode chamber. Note that an exhaust pipe 12 is provided protruding from the bottom surface of the plus pulp 11. By the way, the above-mentioned parts are sealed by a glass 7 lift, and in the electrode chamber and the discharge path 4 there is a discharge scarlet (large size) made of inert gas such as argon and mercury vapor.

[Issues to be Solved by the Invention 1] Incidentally, although this type of fluorescent lamp is small in nature, since each discharge path 4 is formed relatively long by the partin tongue 3 etc., it is difficult to start the fluorescent lamp. The voltage is surprisingly high, reaching over 400 V, especially at low ambient temperatures below 0°C.

When the starting voltage is high in this way, it is necessary to construct the lighting circuit that lights the fluorescent lamp using components with high voltage resistance, and it is also necessary to provide a large distance between the wiring patterns of the printed circuit board on which the components are mounted. However, there were problems in terms of cost and reliability.

The present invention has been made in view of the above points, and an object of the present invention is to provide a fluorescent lamp whose starting voltage can be lowered.

[Means for Solving the Problems 1] In order to achieve the above object, the length of at least one discharge path is formed to be shorter than the length of the other discharge paths.

Note that the above object can be achieved even if the cross-sectional area of at least one discharge path is made larger than the cross-sectional area of the other discharge paths.

In addition, in order to further reduce the decrease in brightness (efficiency), it is possible to shorten the discharge path near the independent electrodes by at least one
It is preferable to form one discharge path shorter than the other discharge paths.

[Function 1] As described above, the present invention forms the length of at least one discharge path shorter than the length of the other discharge paths, lowers the discharge starting voltage in the shortened discharge path, and furthermore, each Since a part of the discharge path is a common discharge space, discharge in the shortened discharge path can induce discharge in other discharge paths, and the discharge starting voltage of the fluorescent lamp as a whole can be lowered. This is what I did.

Note that even if the cross-sectional area of at least one discharge path is made larger than the cross-sectional area of the other discharge paths, the entire discharge starting voltage can be lowered by lowering the firing voltage of one discharge path.

Furthermore, if the length of at least one discharge path is made shorter than the length of the other discharge paths by shortening the discharge path near the independent electrode, the reduction in brightness (efficiency) can be further reduced.

[Example 1] Generally, when lowering the discharge starting voltage of a fluorescent lamp,
The following methods can be considered.

1. Enclosed discharge device lowers large pressure.

2. Shorten the distance between electrodes.

3. Increase the cross-sectional area of the discharge path.

4. Add an auxiliary electrode for starting.

However, the above-mentioned methods each have the following problems in the case of ordinary fluorescent lamps.

1. In this case, the life of the fluorescent lamp will be shortened.

2. 3. In this case, lamp efficiency decreases.

In case 4, the structure of the fluorescent lamp and the lighting circuit become complicated, leading to an increase in cost.

Incidentally, the fluorescent lamp of which the present invention is based has a form in which a plurality of discharge tubes are combined, so to speak, and a portion of each discharge path is a common discharge space. Therefore, when discharge starts in any one of the plurality of discharge paths, the other discharge paths also start discharging. In other words, electrons and ions are supplied from the discharge path where the discharge started to other discharge paths,
This becomes a seed for discharge in other discharge paths, and therefore, when discharge is started in any discharge path, discharge is immediately started in the other discharge paths. Therefore, in the N-quadrant fluorescent lamp of the present invention, by lowering the firing voltage of at least one discharge path, the firing voltage of the entire fluorescent lamp can be lowered. Moreover, if a part of each discharge path is a common discharge space as in this fluorescent lamp, even if the length of one discharge path is shortened in order to lower the discharge starting voltage in one discharge path, for example, When viewed from the perspective of the entire fluorescent lamp, the overall discharge path can be shortened by a smaller proportion than a normal fluorescent lamp with only one discharge path, and therefore the reduction in lamp efficiency of the fluorescent lamp as a whole can be kept to a minimum. I can do it. The same thing can be said when the cross-sectional area of one discharge path is increased.

Hereinafter, an embodiment will be described in which the length of at least one discharge path 4 is formed shorter than the length of the other discharge paths to lower the discharge starting voltage. Fig. 1 shows a fluorescent lamp as an example of this embodiment, and as it is clear from the figure, the overall structure of this example is almost the same as the fluorescent lamp described in the conventional example, so redundant explanation will be omitted. However, only the features of this embodiment will be explained below.

In this embodiment, a case is shown in which one discharge path 4R is formed short. In other words, as shown in FIG.
It is formed to be shorter than the length of the particilane 3 of C, thereby shortening the length of the discharge path 4R. In this way, the distance between the anode electrode 7R and the common cathode electrode 10 can be substantially shortened, which lowers the discharge starting voltage of this discharge path 4P, thereby lowering the discharge starting voltage of the fluorescent lamp as a whole. I can do it.

To explain the effect of this embodiment using specific numerical values, a conventional fluorescent lamp with an inter-electrode distance of about 261 mm and a discharge path width of about 3.5 mm has a maximum discharge starting voltage of 430 V at an ambient temperature of 0°C. There was, but partition 3 of discharge path 4R
If ゛ is shortened by 1.2 wheels, the discharge starting voltage will be up to 370
(2) The discharge starting voltage could be lowered by about 60V. For this reason, the components of conventional lighting circuits have a withstand voltage of 60
It was necessary to use a 0V type, but a lower one with a withstand voltage of 400V was fine.Moreover, if the discharge start voltage could be lowered, the printed circuit board on which the components of the lighting circuit are mounted could be used. The distance between patterns can also be reduced, making it possible to downsize the board and improve reliability. By the way, by shortening Particilan 3' by 1.2 mm, the discharge path 4R
Although the lamp efficiency of the fluorescent lamp itself decreased by about 7%, the decrease in lamp efficiency of the fluorescent lamp as a whole was suppressed to only 2%, which is about 1/4 of that decrease.

By the way, in the case of FIG. 1, only the length of the discharge path 4R is formed short, but in consideration of the molding balance of the base body 1 formed of ceramic or the like, the discharge path at the diagonal position (for example, 4
Particilan 3 of cs 4 c) may be shortened uniformly.

In addition, as shown in FIG. 2, the L-shaped particilan 3a protrudes from the partition wall 2, and the particilan 3 protrudes from the inner surface of the side wall along the anode electrode 7.
The present invention can be applied in the same manner to a fluorescent lamp formed of a fluorescent lamp shown in FIG. .

That is, in the case of FIG. 2, the lengths of the partitions 3 m' and 3 b' in the discharge path 4 are shorter than the lengths of the partitions 3 at 3 b in the other discharge paths 4.

In a conventional fluorescent lamp with the structure shown in Figure 2, the distance between the electrodes is approximately 37 mm, and the discharge path width is approximately 2.5 mm, the ambient temperature is θ℃.
The maximum discharge starting voltage was 640 mm, but if the lengths of the two particilans 3 m' and 3 b' of the discharge path 4R were shortened by 0.8-1, the discharge starting voltage was 55 mm.
0V, and the discharge starting voltage could be lowered by about 90V. As a result, in conventional lighting circuits, it was necessary to use component parts with a withstand voltage of 800μ, but with a withstand voltage of 600μ,
You can now use one rank lower than v. Furthermore, reliability can be expected to improve due to the reduction in discharge starting voltage. Incidentally, the decrease in lamp efficiency in the fluorescent lamp having the structure shown in FIG. 2 remained within 3%. It should be noted that having a plurality of particirans 3 as described above has the advantage of increasing the degree of freedom in adjusting the length of the particillans 3.

By the way, even if the fluorescent lamp has a different structure from the fluorescent lamps shown in FIGS. 1 and 2, the discharge space is integrated! In the case of 1+4, the discharge starting voltage can be lowered by forming at least one discharge path 4 shorter than the other discharge paths. FIG. 3 shows an example of this. In this fluorescent lamp, three anode electrodes 7 R17ce 7 n and 1
a substantially rectangular discharge path 4R94° on the upper surface of the base 1;

4B are arranged in parallel, and an anode electrode 7 is arranged at one end of each discharge path 4, and a discharge hole 6R=6C*6B is formed at the other end, which communicates with an electrode chamber in which a common cathode electrode 10 is housed. It is. In this fluorescent lamp, a bulb 11 made of Fe--Ni--Cr alloy (so-called 426 alloy) is used instead of the lath bulb.

When forming at least 61 discharge paths 4 to have a short length in a fluorescent 2 lamp with such a structure, as shown in FIG. 3, the formation position of the discharge hole (6R in FIG. )
Just move it to the side.

For example, in the structure shown in Fig. 3, the distance between the electrodes is approximately 25 II 1
11. In a conventional fluorescent lamp with a discharge path width of approximately 4+++ m, the maximum discharge starting voltage at an ambient temperature of 0°C was 405 V, but if only the discharge hole 6R was formed close to the anode electrode 7R, the discharge would start. The voltage reached a maximum of 315V, and the discharge starting voltage could be lowered by about 90V. For fluorescent lamps of this construction, the reduction in lamp efficiency was kept within 5%.

[Embodiment 21] In this embodiment, the cross-sectional area of at least one discharge path 4 is made larger than the cross-sectional area of the other discharge paths 4 to lower the discharge starting voltage.

An example of this is shown in FIG. The fluorescent lamp of FIG. 4 has the same structure as the fluorescent lamp of FIG. 1 of the first embodiment, and by forming the discharge hole 6R larger than the other discharge holes 6c, 6Ry6r, the discharge path 4R is The cross-sectional area of the other discharge path 4
C=4 Bt 4 It is larger than C. In other words, by enlarging the discharge holes 6 that locally constrict the discharge path 4, the impedance of the discharge path 4 is lowered, which is essentially equivalent to increasing the area of the discharge path 4.

For example, the distance between the electrodes is about 2,611 m, and the discharge path width is about 3.
5-1, the maximum discharge starting voltage at an ambient temperature of 0°C is 4
With a 30V conventional fluorescent lamp, the discharge hole 6R of the discharge path 4R
When the radius was expanded from a radius of 2.0 ms to a radius of 2.7 ms+, the discharge starting voltage became a maximum of 400 cm, and it was possible to lower the discharge starting voltage by about 30V.

Note that due to the enlargement of the discharge hole 6, the lamp efficiency of the discharge path 4R itself decreases by about 2%, but for the fluorescent lamp as a whole, only about 1/4 of this was able to be suppressed to within 0.5%. . Therefore, the same effect as when the length of at least one discharge path 4 is increased can be obtained. In this case as well, considering the molding balance of the base body 1 made of ceramic etc., the discharge holes are arranged diagonally (for example, 6 c = 6 c).
may be expanded evenly.

Another way to increase the cross-sectional area of the discharge path 4 is #5.
As shown in the figure, this can also be achieved by cutting the partition wall 2 portion facing the discharge path 4R. For example, the discharge path 4 of a conventional fluorescent lamp with an inter-electrode distance of about 26mm and a discharge path width of about 3.5161mm.
When the discharge path width of R was set to 3.81, the discharge starting voltage was 360 cm at maximum, which was able to be lowered by about 70V.

In this case, the decrease in lamp efficiency was kept within 2%.

FIGS. 6 and 7 show a fluorescent lamp of the first embodiment having the structure shown in FIG. In FIG. 6, the discharge hole 6R is made larger than the other discharge holes 6, and in FIG. 7, the width of the discharge path is widened by cutting away the partition wall 2fflS facing the discharge path 4R.

For example, in a conventional fluorescent lamp with the structure shown in Figure 6, the distance between the electrodes is about 37 cm, and the discharge path width is about 2.5 rings, the maximum discharge starting voltage was 640 V at an ambient temperature of 0°C. However, the discharge hole 6R with a radius of 1.8 ml1 is arranged on one side by 2,5
When the discharge path is formed into a square shape of 11M (Fig. 6), the maximum discharge starting voltage is 585μ, and the discharge path width is 2.7InI.
11 (Figure 7), the maximum discharge starting voltage is 560V.
It became. Incidentally, the decrease in lamp efficiency in this case was kept within 1% and 3% by the methods shown in FIGS. 6 and 7, respectively.

Still other examples are shown in FIGS. 8 and 9. The structure of this fluorescent lamp is the same as that of the fluorescent lamp of the first embodiment shown in FIG. 3; in the case of FIG. 8, the discharge hole 6R is formed large, and in the case of FIG. 9, the width of the discharge path 4R is widened. It is something. In addition, in FIGS. 8 and 9, each discharge hole 6 is a substantially rectangular hole.

In a conventional fluorescent lamp with the structure shown in Fig. 8 and an electrode distance of about 2511 and a discharge path width of about 4 bells, the maximum discharge starting voltage at an ambient temperature of 0°C was 420V, but the discharge path of the discharge hole 6R By changing the width of 4R along the direction of force from two wheels to 41 (Fig. 8), the discharge starting voltage can be lowered to a maximum of 375V, and by setting the width of discharge path 4R to 4.4 iam (Fig. 8). (Fig. 9), the discharge starting voltage could be lowered to a maximum of 330V. The reduction in lamp efficiency in this case is 1.5
%, don't stay within 4%.

Note that it is also possible to further lower the discharge starting voltage by combining the method of widening the discharge path width and the method of enlarging the discharge hole in each of the above-described specific examples.

[Example 31 This example is similar to the first example, in which the length of at least one discharge path 4 is made shorter than the other discharge paths 4 to lower the discharge starting voltage. The embodiment is particularly characterized in that the length of the discharge path 4 on the anode electrode 7 side is shortened.

An example is shown in FIG. 10, and the structure of the fluorescent lamp is the same as that of the first embodiment shown in FIG. The discharge path on the inner anode electrode 7P side is shortened. With this structure, in a conventional fluorescent lamp with an inter-electrode distance of about 26 mm, a discharge path width of about 3.51 mm, and a maximum discharge starting voltage of 430 cm at an ambient temperature of θ°C, the anode electrode 7R is 1.5-common cathode. When brought close to the electrode 10, the discharge starting voltage reached a maximum of 360V. Therefore, the same effects as in the case of tISl and the second example were obtained.

Note that when the anode electrode 7R is brought closer to the common cathode electrode 10 to reduce the distance between the electrodes, the lamp efficiency of the discharge path 4R itself decreases by about 5%, but the efficiency of the fluorescent lamp as a whole decreases by about 1/2%.
It remained within just 1.2% of 4. Here, as described above, a fluorescent lamp in which the anode electrode 7 is brought closer to the common cathode 'IIL pole 10 to shorten the distance between the electrodes, and as in the first embodiment, the length of the partition 3 is shortened to shorten the distance between the electrodes. Comparing the luminance distribution between a shortened fluorescent lamp and a conventional fluorescent lamp, it is clear from FIG. This lamp has less reduction in brightness (efficiency) than the fluorescent lamp, which has a shortened distance between the electrodes by shortening the length of partition 3 (shown by the thin broken line in the figure), and compared to the conventional fluorescent lamp (shown by the solid line in the figure). Even brightness (efficiency)
The drop will be less.

By the way, in the case of FIG. 10, the anode electrode 7 of the discharge path 4R
Only R was placed close to the common cathode electrode 10, but considering the molding balance of the base 1 made of ceramic etc.
Anode electrodes 7C*7C arranged in diagonal discharge paths (for example, 4c+4r) are evenly connected to common cathode electrodes 10.
The same effect can be obtained even if it is brought closer to .

FIG. 12 shows a fluorescent lamp corresponding to the fluorescent lamp of FIG. 2 of the first embodiment, in which the length of the discharge path 4 on the anode electrode 7 side is particularly shortened to lower the discharge starting voltage. In this fluorescent lamp, each discharge path 4 has particulate silane 3a.
are all formed to have the same length and shape, and the discharge path 4R
Participant 3b' is the only other partition 31
). For example, in the structure shown in FIG. 12, the distance between the electrodes is about 37 am, the discharge path width is about 2 am,
In a conventional fluorescent lamp with a discharge starting voltage of 5 mm and a maximum discharge starting voltage of 640 cm at an ambient temperature of 0°C, if the length of each partition 3b' of the discharge path 4R is shortened by 1.5, the discharge starting voltage becomes 550 V, and the discharge starts. Set the starting voltage to about 90
I was able to lower the V. Incidentally, the decrease in lamp efficiency in the fluorescent lamp having the structure shown in FIG. 2 was kept within 2.5%. Here, as described above, a fluorescent lamp in which the length of the discharge path 4R is shortened by the partition 3b', a fluorescent lamp in which the length of the discharge path 4R is shortened by shortening the length of the particilan 3a, and a conventional fluorescent lamp. Comparing the luminance distributions in Figure 13, it is clear from Fig. 13 that the fluorescent lamp in which the discharge path 4P is shortened by the partition 3b' shown by the thick broken line in the figure has a longer length of the partition 3a shown by the thin broken line in the figure. The reduction in brightness (efficiency) is smaller than that of a fluorescent lamp with a shorter discharge path 4R, and the brightness (efficiency) is also lower than that of a conventional fluorescent lamp, which is shown by the solid line in the figure.
The drop will be less. Note that the above-mentioned partition 3b'
The method of shortening only the anode electrode 7P is an effective method when the position of the anode electrode 7P cannot be moved due to the positional relationship with the glass bulb 11.

[Effect of the Invention 1] As described above, the present invention has the length of at least one discharge path shorter than the length of the other discharge paths, so that the distance between the electrodes in the shortened discharge path is reduced. By shortening the discharge path, the discharge starting voltage in this discharge path can be lowered, and therefore, the discharge in the other discharge path, a part of which has become a common discharge space, can be induced by the discharge in the shortened discharge path,
The discharge starting voltage of the fluorescent lamp as a whole can be lowered, and therefore components with lower voltage resistance can be used as components of the lighting circuit, reducing costs. can be made smaller,
This has the advantage that the lighting circuit can be made smaller and its reliability can be improved. Note that reducing the distance between the electrodes will result in a decrease in lamp efficiency, but this article is intended for fluorescent lamps that are a combination of so-called multiple discharge tubes in which a portion becomes a common discharge space. Decrease in lamp efficiency of the fluorescent lamp as a whole can be kept small.

Note that even if the cross-sectional area of at least one discharge path is made larger than the cross-sectional area of the other discharge paths, the entire discharge starting voltage can be lowered by lowering the firing voltage of one discharge path.

Furthermore, if the length of at least one discharge path is made shorter than the length of the other discharge paths by shortening the discharge path near the independent electrode, the reduction in brightness (efficiency) can be further reduced.

[Brief explanation of drawings]

Figure 1 (a)? (b) is a plan view and a sectional view of a first specific example of the first embodiment of the present invention, FIGS. 2(a) and (b) are a plan view and a sectional view of a second specific example, and FIG. Figures (a), (b)
FIG. 4(a) is a plan view and a sectional view of the third specific example. (b) is a plan view and a sectional view of the first specific example of the second embodiment, FIG. 5 is a plan view of the second specific example, and FIG. 6 (a) *(
b) is a plan view and a sectional view of the third specific example, and FIG. 7 is a fourth specific example.
8(a) and (b) are a plan view and a sectional view of a specific example of fjS5, FIG. 9 is a plan view of a sixth specific example, and FIG. 10(a), ( b) is a plan view and a sectional view of the first specific example of the third embodiment, FIG. 11 is a characteristic diagram showing the luminance distribution of the same as above, and FIG. 12(a). (b) is a plan view and a sectional view of the second specific example, FIG. 13 is a characteristic diagram showing the brightness distribution of the same as above, and FIG. 14 (a). (1)) is a plan view and a sectional view of a conventional example. 4 Rt 4 Ct 4 B is a discharge path, 7 Rt 7
(, +7 B is the anode electrode, 10 is the common cathode electrode.

Claims (3)

[Claims] (1) A discharge path is formed with one common electrode and a plurality of independent electrodes, with the common electrode side being common and each independent electrode side branching out for each independent electrode, and a discharge path is formed between each independent electrode and the common electrode. A fluorescent lamp in which each branch discharge path section emits light by applying a voltage, wherein the length of at least one discharge path is formed shorter than the length of the other discharge paths. (2) A discharge path is formed with one common electrode and a plurality of independent electrodes, with the common electrode side being common and each independent electrode side branching out for each independent electrode, and a high voltage between each independent electrode and the common electrode. A fluorescent lamp in which each branch discharge path section emits light by applying a voltage, wherein the cross-sectional area of at least one discharge path is larger than the cross-sectional area of the other discharge paths. (3) The fluorescent lamp according to claim 1, wherein the length of at least one discharge path is made shorter than the length of the other discharge paths by shortening the discharge path near the independent electrode.