JPH0433640Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a fluorescent lamp whose emission color can be freely changed.

[Background technology]

Regarding a variable color fluorescent lamp that can emit light of any color, the applicant has proposed a lamp having a structure as shown in FIG.

In the figure, 1R, 1G, and 1B are U-shaped bent glass tubes, each with a phosphor 2R (for example, a red phosphor) and a 2G phosphor having different luminescent colors on their inner surfaces.
(for example, a green phosphor) and 2B (for example, a blue phosphor) are coated. Each glass tube 1R, 1G,
One end of 1B is connected to anode electrodes 3R, 3G, 3, respectively.
It is sealed together with B on the stem plate 7. 4 is a cathode electrode as a common electrode, which is disposed on a button stem 6 having an exhaust pipe 5. The button stem 6 is sealed approximately at the center of the stem plate 7. 8
is an electrode chamber cover whose open end is sealed to the stem plate 7, and holes 9R, 9G, 9B corresponding to the respective glass tubes 1R, 1G, 1B are provided on the upper surface.
The open ends of glass tubes 1R, 1G, and 1B are sealed to the peripheries of these holes 9R, 9G, and 9B, respectively. Then, an airtight container 1 consisting of each glass tube 1R, 1G, 1B, an electrode chamber cover 8 and a stem plate 7
A discharge gas is sealed in a space defined by 0 and 0. 11 is a glass frit that realizes airtight sealing of each part.

As shown in FIG. 2, each anode electrode 3R,
3G and 3B are each connected to a selection switch SW (specifically, a transistor switch control for varying the duty) from a DC power supply DC via a resistor R serving as a ballast. ST is a starter for starting.

Discharge occurs between the anode electrodes 3R, 3G, 3B and the common cathode 4. By increasing the switching cycle of the selection changeover switch SW and arbitrarily changing each duty ratio, each discharge path 12R, 1
The emission ratio of 2G and 12B changes smoothly, for example,
By adding the light diffusing globe 13 to improve color mixing, a flexible emission color can be obtained.

By the way, the above-mentioned lamp has the following problem with respect to color mixing. FIG. 3 shows a plan view when the light diffusion globe 13 is added to the lamp. Since the three arc tubes 1R, 1G, and 1B extend radially outward from the center of the lamp, the arc tube 1 and A portion where the glove 13 is close to each other occurs.
When lighting the lamp in this state and adjusting the color, the arc tube 1 that is close to this part (the area indicated by the broken line in the figure)
The emitted light color was strongly reflected, and the globe 13 as a whole had large color unevenness, giving an unfavorable appearance.

[Purpose of invention]

The present invention was made in order to improve the above-mentioned problems, and it is an object of the present invention to provide a lamp structure that improves the color mixing properties of the lamp as described above.

[Disclosure of invention]

In order to evaluate color mixing, the inventor of the present invention
We prototyped three U-shaped fluorescent lamps of the same shape and size that emit monochromatic green and blue light, covered these three lamps with bullet-shaped light diffusion globes, and tried to improve color mixing by changing the arrangement of the lamps. I considered it.

As a result of experiments, it was found that the best color mixing was achieved when both ends of each U-shaped fluorescent lamp were lined up on the same circumference drawn around the center of the light diffusion globe, which looked like a circle when viewed from above. Ta.

In the following embodiments, the structure of a variable color fluorescent lamp that satisfies this condition will be explained with reference to the drawings.

<Example 1> In this example, as shown in the plan view of FIG. 4 and the developed cross-sectional view of FIG. , and the positions of the anode electrodes 3R, 3G, 3B
By arranging the stem plate 7 and the electrode chamber cover 8 lower than before (that is, reversing the positional relationship of the stem plate 7 and the electrode chamber cover 8 from the conventional one), it is possible to arrange both ends of each of the three arc tubes 1R, 1G, and 1B on the same circumference. It is something to do.

In addition, 8a in the figure is the application of glass frit 11,
A flange for easy and reliable sealing.
With this configuration, the electrode chamber cover 8
Ease of lamp manufacturing is not impaired even if the above-mentioned reversal is performed. Furthermore, in this embodiment, U-shaped glass tubes 1R, 1G, and 1B with equal leg lengths can be used, which facilitates their manufacture.

Further, 3S is an auxiliary anode electrode, and FIG. 6 shows a lighting circuit diagram when this auxiliary anode electrode 3S is used.
The effect of using the auxiliary anode electrode 3S is that the distance between it and the common cathode electrode 4 is very short compared to the other anode electrodes 3R, 3G, and 3B.
Inserting the starter ST during this time will make starting the lamp extremely easy.

Discharge path 12S by selection switch SW
A dimming function can be obtained by changing the duty ratio of . This is because there is no fluorescent material to emit light in the discharge path 12S formed by the auxiliary anode electrode 3S. Note that R' in the figure is a resistance for making the lamp current equal to that of the other discharge paths 12R, 12G, and 12B.

Since the other configurations are similar to those of the conventional example, corresponding parts are given the same reference numerals and explanations will be omitted.

<Example 2> In this example, as shown in the developed cross-sectional view of FIG.
The exhaust pipe 5 is provided at the center of the upper surface of the stem plate 7. As a unique effect of this configuration, compared to the conventional example in which the exhaust pipe 5 protrudes from the button stem 6, attachment of the cap (not shown) becomes easier.

Since the inner diameter of the exhaust pipe 5 can be increased, the exhaust speed during lamp exhaust can be increased, the time for the exhaust process can be shortened, and residual impurity gas in the lamp can be reduced, resulting in stabilization of lamp characteristics.

While the lamp is on, the exhaust pipe 5 becomes the coldest point, so mercury vapor pressure can be regulated. In particular, since the lamp according to the present invention is usually used with the globe 13 added, the effect was remarkable. Note that, for convenience, only two U-shaped glass tubes are depicted in FIG.

<Embodiment 3> In this embodiment, as shown in FIGS. 8a and 8b, the button stem 6 in the electrode chamber cover 8 is replaced with a less expensive pinch stem 16. In this case, in order to reduce the height of the electrode chamber cover 8, the common cathode 4 is attached by bending the lead wire. Note that the auxiliary anode electrode 3S may be provided as an independent pinch stem 16', as shown in FIG.

[Effects of the invention] As described above, the present invention seals an electrode to one end of each of three U-shaped glass tubes whose inner surfaces are coated with phosphors of different luminescent colors, and The other end of the glass tube is connected to an airtight container provided with a common electrode, and a discharge gas is sealed in a space defined by each of the U-shaped glass tubes and the airtight container. , the cross-sectional shape of the airtight container is formed into a substantially triangular shape in plan view, and is arranged below the electrode-sealed end of the U-shaped glass tube, and both ends of each U-shaped glass tube are arranged on the same circumference. This arrangement improves color mixing when used with a light diffusion globe, and also minimizes the outside diameter of the lamp, making it possible to create a more compact fluorescent lamp with high commercial value. I was able to provide it.

[Brief explanation of drawings]

FIG. 1 is a developed sectional view of a conventional example, FIG. 2 is a lighting circuit diagram of the same lamp, FIG. 3 is a plan view of the lamp, and FIGS. 4 to 8 show embodiments of the present invention.
FIG. 4 is a plan view of the first embodiment, FIG. 5 is a developed sectional view of the same, FIG. 6 is a lighting circuit diagram of the same lamp, and FIG.
The figure is a developed cross-sectional view of the second embodiment, and FIGS. 8a and 8b are cross-sectional views showing essential parts of the third embodiment, respectively. 1...U-shaped glass tube, 2...fluorescent material, 3...
Electrode, 4... Common electrode, 10... Airtight container.

Claims (1)

[Scope of utility model registration request] An electrode was sealed to one end of each of three U-shaped glass tubes whose inner surfaces were coated with phosphors of different luminescent colors, and a common electrode was arranged at the other end of the U-shaped glass tubes. Each U is in communication with an airtight container.
A fluorescent lamp comprising a discharge gas sealed in a space defined by a letter-shaped glass tube and an airtight container, wherein the airtight container has a triangular cross-sectional shape in plan view, and the U-shaped glass tube A fluorescent lamp characterized in that the U-shaped glass tube is arranged below the electrode-sealed end thereof, and both ends of each U-shaped glass tube are arranged on the same circumference.