JPH03280352A - Low pressure discharge lamp - Google Patents

Abstract

PURPOSE:To provide selectivity for the light emission region and the color in light emission by coupling a plurality of bulbs coated at the insides with fluorescent films emitting respective colors, using this coupling part for intermedi ate electrode, and allowing it to serve together with the end electrodes selective ly. CONSTITUTION:A plurality of, e.g. three, light emitting tubes 2a-2c are coupled together, and their insides are coated with fluorescent films emitting differently specified colors. End electrodes 5a, 5b are installed at the two ends of bulb coupled, and intermediate electrodes 10a, 10b are provided at the coupling part in the middle. The electrodes are connected with an inverter circuit 20 of the power supply via switches 21-24. The bulb located between switches emits light through selective use of two of the switches 21-24. Thus, a variety of light emitting modes are available with different light quantities and emitted colors using a simple configuration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a low-pressure discharge lamp having an overall bent discharge path such as a U-shape or a W-shape.

(Prior Art) Fluorescent lamps are widely used as light sources for general lighting, OA equipment, and other lighting devices. Fluorescent lamps have excellent luminous efficiency and have a long light emitting area along the bulb axis of the arc tube bulb, so they are advantageous when illuminating a correspondingly long area with approximately uniform brightness over the entire area. be.

Usually, when the irradiated surface has a flat spread,
A planar light source was constructed by arranging a plurality of independently formed straight tube fluorescent lamps in parallel.

However, a lighting device configured by arranging multiple straight tube fluorescent lamps in parallel requires, for example, the desire to illuminate only a part of the irradiated surface, or to make the brightness locally brighter than other areas. Conventionally, this was handled by turning on only some of the lamps and turning off the rest.

(Problem to be Solved by the Invention) However, the structure in which a large number of straight tube fluorescent lamps are arranged in parallel as described above requires an electrode for each lamp because each lamp is independent. , the number of electrodes used increases, a large number of sockets, sockets and lamp holders are required, and wiring becomes complicated.

On the other hand, OA equipment that uses photoelectric conversion, such as copying machines,
Fluorescent lamps are used as light sources in facsimiles, image scanners, OCR, etc., but conventionally, the color of light emitted by a single lamp, that is, the spectrum, has been determined.

However, if the color written on a document or the like is the same as the emitted light color, there is a problem in that reading is missed, and in this case, a different emitted color is required. To do this, it is necessary to have multiple fluorescent lamps that emit light of different colors, but in this way, each lamp is independent, so each lamp can be Electrodes are required, and there are problems such as a large number of electrodes being used and a complicated structure.

The present invention has been made based on the above circumstances, and it is an object of the present invention to provide a low-pressure discharge lamp that has a relatively simple structure and can selectively change the length of light emitted from the lamp and the color of light emitted from the lamp.

[Structure of the Invention] (Means for Solving the Problems) The first aspect of the present invention is to connect a plurality of bulbs each having a phosphor coating formed on the inner surface, and to connect the ends of these bulbs to each other so that they are electrically connected to each other. comprising a connecting member and end electrodes respectively installed at both ends of a discharge path formed by the bulb and the connecting member, the connecting member being made of a conductive member, thereby making the connecting member an intermediate electrode; The present invention is characterized in that the bulb is selectively turned on by selectively switching the end electrode and the intermediate electrode to cause discharge.

The second aspect of the present invention is a plurality of bulbs each having a phosphor coating formed on the inner surface thereof, a connecting member that connects the ends of these bulbs and is provided in common to these bulbs, and a connecting member that is installed on each of the bulbs. The connecting member is formed of a conductive member to serve as a common electrode, and the common electrode and each of the end electrodes are selectively switched to discharge the bulb. It is characterized by being able to be turned on selectively.

A third feature of the present invention is that the luminescent colors of the phosphor coatings formed on the inner surface of each bulb are made to differ from each other, and the bulbs are selectively lit by switching the electrodes to vary the luminescent color. .

(Function) According to the first aspect of the present invention, when a voltage is applied between the end electrodes installed at each end of the discharge path to cause light emission, the entire length of the discharge path emits light, and one end electrode When a voltage is applied between the discharge path and the intermediate electrode to cause light to emit light, a region of the entire length of the discharge path between the one end electrode and the intermediate electrode emits light. Therefore, by selecting the electrode connected to the power source, the length of light emission and the light emission area can be changed, and the amount of light emission can also be selected. In this case, since the intermediate electrode is constituted by a connecting member that electrically connects the bulbs to each other, there is no need for a special intermediate electrode, and the structure is simplified.

Further, according to the second aspect of the present invention, when a voltage is applied between the common electrode and the end electrode installed at the end of each bulb, all the bulbs emit light, and the common electrode and the end electrode installed at one end of the bulb emit light. When a voltage is applied between the electrodes of the bulb and the bulb emits light, only this bulb emits light.

Therefore, the amount of light emission can be selected by selecting the electrode connected to the power source. In this case as well, the common electrode is constituted by a connecting member that electrically connects the bulbs to each other, so there is no need for a special common electrode, and the structure is simplified.

Further, according to the third aspect of the present invention, since the phosphor coatings formed on the inner surfaces of the plurality of bulbs emit light of different colors, it is possible to change the light emitting area and the color of the emitted light by selecting the electrodes.

(Example) The present invention will be described below based on a first example shown in FIGS. 1 to 4.

In the figure, 1 is a fluorescent lamp, and this fluorescent lamp 1 has three U-shaped glass bulbs 2a.

2b and 2c are connected to each other to form a meandering discharge path as a whole. Each valve 2a.

2b and 2c are each bent into a U-shape and have a flat cross-sectional shape, and when connected to each other, the whole is curved so as to be located on the same circumference as shown in FIG. ing.

As shown in FIG. 2, the inner surface of each glass bulb 2a, 2b, 2C is provided with a phosphor coating 3a, 3b.

3C is formed. These phosphor coatings 3a.

3b and 3c are the three primary colors of light: blue (B), green (G), and red (R).
) may be used to emit light of the same color in all bulbs using a 3-wavelength range phosphor mixed with phosphors of The phosphor of the second bulb 2b is, for example, 543nl.
The phosphor of the third bulb 2c is, for example, 6
This is a phosphor that emits a red (R) color with a peak wavelength of 1111.

Note that these U-shaped glass bulbs 2a and 2b.

2C has a continuous wall 4 formed inside the U-shaped discharge path to reinforce the bulb.

Stems 6a, 6b provided with electrodes 5a, 5b are sealed to the U-shaped glass bulbs 2a, 2c at both ends of the discharge path of these U-shaped glass bulbs 2a, 2b, 2c. In addition, these U-shaped glass bulbs 2g,
2b and 2c are electrically connected at their ends by connecting members 10a and 10b.

As shown in FIGS. 1 and 2, the stems 5a and 6b are so-called button stems made of flat glass, and have a pair of lead wires (wells) 7a and 7, respectively.
b is hermetically penetrated, and these lead wires 7a, 7b
The electrodes 5a and 5b made of hot cathodes are installed at the inner ends of the electrodes 5a and 5b.

Such button stems 6a, 6b are attached to the bulbs 2a, 2b with a glass adhesive (frit glass) not shown.
are hermetically joined to each open end.

Therefore, since these electrodes 5a and 5b are located at the ends of the discharge path, they are called end electrodes.

On the other hand, the U-shaped glass bulbs 2a and 2b.

As shown in FIG. 2, the connecting members 10a and 1Qb connecting 2C include a connecting member main body 8 made of a conductive metal such as stainless steel and having an elongated cylindrical shape with a bottom, and an upper opening of the connecting member main body 8. It is composed of a lid body 9 made of metal such as stainless steel, which is covered with a lid. The connecting member main body 8 integrally has a flange portion 8a on the upper surface, and a rising peripheral wall 8b is formed around the flange portion 8a.
The flange portion 8a is located inside the rising peripheral wall 8b.
The lid 9 is fitted so as to rest on top of the connecting member main body 8 and the lid 9 are hermetically joined by frit glass (not shown).

A pair of connection ports 9a, 9a are protruded from each of the lids 9, and these connection ports 9a, 9a are located inside the ends of the U-shaped glass bulbs 2a, 2b and the ends of 2b, 2c. It is designed to be fitted into the

And the connecting member thus formed], Oa.

10b extends between each end of the U-shaped glass bulbs 2a, 2b, and 2C and is hermetically joined by frit glass.

Therefore, the U-shaped glass bulbs 2a, 2b, 2c are connected to the connecting members 1.0a, 1.0a. The connecting members 10a and 10b are mechanically connected to each other through the internal spaces of the connecting members 10a and 10b so that the discharge paths are electrically connected to each other.

Note that a predetermined amount of mercury and rare gas are sealed inside the bulb.

Since the connecting member main body 8 is formed of a conductive material, it directly functions as an electrode, and therefore a lead wire is directly connected to the connecting member main body 8 and connected to the inverter circuit 20 as shown in FIG. . In other words, since these connecting members 10a and 10b are arranged in the middle of the meandering electrical path, they constitute intermediate electrodes, and serve both the function of connecting the valves and the function of electrodes.

The above-mentioned end electrodes 5a, 5b and intermediate electrodes] Oa, 10b
are connected to the inverter circuit 20 via switches 21, 22, 23, and 24, respectively, and the inverter circuit 20 is connected to a power source 25.

The operation of the fluorescent lamp having such a structure will be explained.

When the switches 21 and 24 are closed, the end electrodes 5a and 5b located at both ends of the discharge path are connected to the inverter circuit 20, and discharge occurs between these end electrodes 5a and 5b. This discharge causes all the bulbs 2a, 2b, and 2c to emit light, and the entire length of the curved discharge path as a whole emits light.

Therefore, the emission length is large and has a planar spread,
Moreover, since the amount of light emitted is large, a wide area can be brightly illuminated.

Furthermore, each bulb 2a, 2b, 2c is blue (B).
) type, green (C) type, and red (R) type, so when all the bulbs emit light as described above, the above three colors are emitted at the same time. It will exhibit a mixed color.

On the other hand, an end electrode 5a provided at the end.

5b, for example, switches 21 and 22, are closed and the end electrode 5a and the intermediate electrode 10a are connected to the inverter circuit 20, between the end electrode 5a and the intermediate electrode 1.0a. A discharge occurs. This discharge causes only the first bulb 2a to emit light among the entire discharge path.

Therefore, in this case, the length of the light emission is equivalent to the length of the first bulb 2a, so the light emission area is small and the amount of light emission is also small, so that a partial area can be illuminated.

In this case, the inner surface of the luminescent bulb 2a is blue (B).
Since the phosphor coating 3a is formed, it emits blue (B) light.

Furthermore, the switches 23 and 24 are closed and the other end electrode 5
b and other intermediate electrodes 1. When Ob is connected to the inverter circuit 20, discharge occurs between the end electrode 5b and the intermediate electrode 10b. This discharge causes only the third bulb 2C to emit light, and in this case as well, the length of light emission is equivalent to the length of the third bulb 2C, and the red (R,) phosphor coating 3C emits red light. emits.

Then, the switches 22 and 23 are closed again, and the intermediate electrode 10
When electrodes a and 10b are connected to the inverter circuit 20, discharge occurs between them and the intermediate electrodes 10a and ]Ob.

Since this discharge causes the second bulb 2b to emit light, the length of the light emission is equivalent to the length of the second bulb 2b, and the edge line formed by the green (G) phosphor coating 3b emits light.

Then, close the switches 21 and 23 to close the end electrode 5a.
When the other intermediate electrode 1nb is connected to the inverter circuit 20, a discharge occurs between the end electrode 5a and the intermediate electrode 10b. This discharge is part of the entire discharge path.
causing the first bulb 2a and the second bulb 2b to emit light;
It emits a mixture of blue (B) and green (G) light.

Furthermore, the switches 22 and 24 are closed and the end electrode 5 is closed.
b and the other intermediate electrode 10a are connected to the inverter circuit 2[], these end electrodes 5b and the other intermediate electrode 1.0
A discharge is made between i%. This discharge causes the second bulb 2b and third bulb 2c of the entire discharge path to emit light, and emits a mixed color of green (G) and red (R) light.

As can be understood from the above explanation, according to the above embodiment, although the lamp has a single discharge path, it is possible to select the light emission length, that is, the light emission area and the light emission amount, and there are six types in total. Emission length and emission color can be selected.

In addition, if you want to select the color of light in OA equipment, etc., each bulb has a phosphor coating that emits a different color, so it is possible to select a total of 6 light colors, which can prevent reading errors. can be prevented.

Since the intermediate electrodes 10a and 10b are constituted by a connecting member that electrically connects the two electrodes to each other,
There is no need for special electrodes such as filaments, the number of sockets and lamp holders used is small, the number of parts is small, wiring is simple, and the structure is simple.

In the above embodiment, three valves 2a, 2b and 2
Although a case has been described in which each of the curves C is bent into a U-shape, the present invention is not limited to this, and as in the second embodiment shown in FIG.

Both 32b and 32c may be straight valves. The inner surfaces of each bulb 32a, 32b and 32C are coated with blue, green and red phosphor coatings 33a, 3, respectively.
3b and 33c (33b is not shown) are formed.

In this embodiment, a mount using a flare stem is adopted as the end electrodes 35a and 35b, and the intermediate electrode 37a
, 37b serve as connecting members for electrically connecting the valves to each other, as in the first embodiment.

Even in this case, the emission length and emission color can be arbitrarily selected.

Next, regarding the third embodiment of the invention, FIGS.
This will be explained based on the diagram.

In the case of the first embodiment, U-shaped valves 2a, 2b, 2
c are arranged in the circumferential direction, and each bulb is connected to each other by a connecting member constituting an intermediate electrode], Oa, and 10b, but in this embodiment, for example, three U-shaped bulbs 42a, 42b, 42
c are arranged radially with respect to one connecting member 41, and the connecting member connecting these valves 42 a s 42 b % 42 c is shared and constitutes the common electrode 41 .

The ends of each bulb 42a, 42b, 42c are sealed with end electrodes 45a, 45b, 45c, respectively, and the inner surfaces of these bulbs 42a, 42b, 42c are coated with phosphor coatings that emit light of different colors. 43a, 43
b, 43c are formed. The phosphor 43a is, for example, a blue (B) type having a peak wavelength of 453 tvl,
The phosphor 43b is, for example, a green (G) type having a peak wavelength of 543 nal, and the phosphor 43c is, for example, a red (R) type having a peak wavelength of 61 ur++n.

In such a configuration, as shown in FIG. 8, when all switches 46, 47, 48 are closed, each valve 42
End electrodes 45as provided at the ends of a142b and 42c
45b, 45c and the common electrode 41, which also serves as a connecting member, are connected to the inverter circuit 20, so a discharge occurs between them, and therefore all the bulbs 42a, 42b, 42c
emits light.

Therefore, blue (B), green (G), and red (R) light colors are emitted simultaneously, and a mixture of these colors is emitted.

Also, if you select and close only one of the switches 46, 47, and 48 above, only the bulb connected to it will light up, and either the blue (B) type, green (G) type, or red (R) type will light up. It emits one type of light.

Furthermore, when any two of the switches 46, 47, and 48 are selected and closed, the valves connected to them will be switched to either the blue (B) system, the green (G) system, or the red (R) system. It emits two types of light. .

Therefore, even in such an embodiment, the amount of light emission and the color of light emission can be switched and selected.

In the case of this embodiment, only one common electrode 41 is required, and since the connecting member that conducts the bulb is used as the electrode, no special filament electrode is required.

Furthermore, the present invention is not limited to the above embodiments.

That is, in each of the above embodiments, each end electrode is composed of a hot cathode made of a filament, and thus the fluorescent lamp is a hot cathode type fluorescent lamp, but the end electrode is made of a nickel plate or the like. It can be similarly implemented as a cold cathode fluorescent lamp.

Furthermore, the present invention is not limited to fluorescent lamps filled with mercury, but can also be implemented with rare gas discharge lamps filled with xenon, neon, or krypton.

[Effects of the Invention] As explained above, according to the first aspect of the present invention, when a voltage is applied between the end electrodes installed at each end of the discharge path to cause light to emit light, the entire length of the discharge path emits light, When a voltage is applied between one end electrode and the intermediate electrode to cause light emission, a region of the entire length of the discharge path between the one end electrode and the intermediate electrode emits light.

Therefore, by selecting the electrode connected to the power source, the length of light emission and the light emission area can be changed, and the amount of light emission can also be selected.

Further, according to the second aspect of the present invention, when a voltage is applied between the common electrode and the end electrode installed at the end of each bulb, all the bulbs emit light, and the common electrode and the end electrode installed at one end of the bulb emit light. When a voltage is applied between the electrodes of the bulb and the bulb emits light, only this bulb emits light.

Therefore, the amount of light emission can be selected by selecting the electrode connected to the power source.

Further, according to the third aspect of the present invention, since the phosphor coatings formed on the inner surfaces of the plurality of bulbs emit light of different colors, it is possible to change the light emitting area and the color of the emitted light by selecting the electrodes.

In any of the cases of the present invention, the intermediate electrode and the common electrode are constituted by a connecting member that electrically connects the bulbs to each other, so there is no need for a special filament FF electrode, and the number of parts is reduced. This has the advantage of simplifying the structure.

and brightness can be selected. Moreover, since this device switches with one discharge path, the number of electrodes used can be reduced, and the configuration can be simplified.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, FIG. 1 is an exploded configuration diagram showing the configuration of a fluorescent lamp and a power supply circuit, and FIG. 2 is an exploded perspective view showing the configuration of a fluorescent lamp. 3 is a perspective view of the assembled state, FIG. 4 is a cross-sectional view taken along the TV-mV line in FIG. 3, and FIG. 5 is a partial cross-section of a fluorescent lamp showing a second embodiment of the present invention. 6 to 8 show a third embodiment of the present invention, FIG. 6 is a perspective view of an assembled state, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 6, and FIG. The figure is a configuration diagram connected to a power supply circuit. 2a, 2b, 2cm...bulb, 3a, 3b, 3c...
- Phosphor coating, 5a, 5b... end electrode, 10a. 10b... Intermediate electrode (connecting member) 21.22.23
．． 24-=switch, 32a, 32b, 32c... bulb, 33a, 33b, 33c... phosphor coating, 3
5a, 35b = one end electrode, 37a, 37b... intermediate electrode (connection member) 42a, 42b. 42 c-...Valve, 43a, 43b, 43cm...
Phosphor coating, 45 a, 45 b, 45 c
One end electrode, 41... common electrode (connecting member), 46.
47.48...Switch.

Claims (3)

[Claims] (1) A plurality of bulbs each having a phosphor coating formed on their inner surfaces, a connecting member that connects the ends of these bulbs to each other for electrical conduction, and both ends of a discharge path formed by the bulbs and the connecting member. and end electrodes respectively installed in the connecting member, the connecting member is made of a conductive member, the connecting member is used as an intermediate electrode, and the end electrode and the intermediate electrode are selectively switched to cause discharge. A low-pressure discharge lamp characterized in that the bulb is selectively lit by: (2) A plurality of bulbs each having a phosphor coating formed on their inner surfaces, a connecting member that connects the ends of these bulbs and is provided in common to these bulbs, and an end electrode that is installed on each of the bulbs. The connecting member is made of a conductive member, so that the connecting member is used as a common electrode, and the common electrode and each end electrode are selectively switched to discharge, thereby selectively lighting the bulb. A low-pressure discharge lamp that is characterized by the following features: (3) The plurality of bulbs each have a different luminescent color from the phosphor coating formed on their inner surfaces, and the bulbs are selectively turned on by switching electrodes to make the luminescent color variable. The low pressure discharge lamp according to claim 1 or 2.