JPH0329261A - Low pressure mercury vapor discharge lamp - Google Patents

Abstract

PURPOSE:To emit a desired color light with strong viewability by one light source by arranging light emitting narrow tubes emitting blue, green, and red colors in order, and providing them with a common discharge electrode. CONSTITUTION:Light emitting narrow tubes 7, 8, 9 of blue, green and red are arranged around the tube 8 emitting green color inside the discharge space 6 divided hermetically by an outer tube 3 and stem 5. An electrode 11 is provided at each tube for selective energization, and a discharge electrode 21 is provided at each tube commonly. With this arrangement, a desired color light is obtained with a discharge lamp formed of one outer tube 3 by selectively light-emitting the tubes 7, 8, 9. Since the arrangement is done around the tube 8, the whole on the display direction side of the tube 3 is made clear and the quality of display is improved with the high viewability.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention can be used as a light source arranged in large numbers on display screens installed in baseball stadiums or stadiums, or as a light source used as a single tube for lighting effects. Regarding low pressure mercury vapor discharge lamps.

[Technical background of the invention and its problems]

Recently, television cameras and video cameras are being used at baseball fields and stadiums.
A display device is installed that projects and displays images stored in the TR on a large display screen. This device displays a predetermined image on the display screen by placing tens to tens of thousands of light sources densely arranged on the display screen and selectively turning on these light sources in accordance with image signals. It looks like this.

By the way, this type of light source currently uses an electron beam to emit a single color of blue, green, or red, and a color light bulb coated with translucent paint that emits a single color of blue, green, or red. There are known devices that emit light.

However, although the electron beam has advantages such as low power consumption and long life, it has the disadvantage that the light source itself is expensive, resulting in high cost. In addition, although light bulbs have the advantage that the light source itself is inexpensive and the control circuit is simple,
On the other hand, it has drawbacks such as high power consumption and short lifespan. Note that such a drawback is not limited to the case where the display screen is provided. For example, traditionally covered light bulbs are
Although it is used as a light source for displaying performances in stores, stages, etc., the above-mentioned drawbacks have arisen even when used in this way.

Therefore, it is conceivable to use a low-pressure mercury vapor discharge lamp, typified by a fluorescent lamp, as another light source. It is well known that fluorescent lamps consume less power, have a long life, have high brightness, and are relatively inexpensive, and from this point of view, they can be said to fully meet the requirements of a light source.

On the other hand, conventional light sources for display or performance display are red,
A set of three light sources that emit blue and green light are used. Therefore, each color of red, blue, and green is 1
If a single light source can emit light, the entire light source for three colors can be made more compact and the cost can be reduced.

[Purpose of the invention]

The present invention was made based on these circumstances, and
The purpose of the present invention is to provide a low-pressure mercury vapor discharge lamp that has a single light source but whose emission color can be changed appropriately depending on the purpose and method of use.

[Summary of the invention]

That is, in order to achieve the above object, the present invention accommodates three U-shaped light emitting tubes each having an electrode at one end and an open end at the other end in a discharge space formed within a translucent outer tube. The inner surface of each light emitting tube is coated with a phosphor coating that emits light of different colors: red, blue, and green, and the discharge space is filled with mercury and a rare gas. A single common electrode is provided for the discharge path, and the three light emitting tubes are arranged side by side with the green light emitting tube in the center.

[Embodiments of the invention]

The present invention will be described below with reference to drawings in which the present invention is applied to a large number of light sources arranged on a display screen.

FIG. 1 shows a schematic diagram of a large display screen installed in a corner of a baseball field or stadium, for example. On a screen board 1 having a substantially rectangular shape, there are several to tens of thousands of light sources 2...
・are densely arranged. These light sources 2 are low-pressure mercury vapor discharge lamps typified by fluorescent lamps, and details thereof are shown in FIG. 2 and subsequent figures.

That is, 3 is an outer tube having a hollow cylindrical shape, and is made of a transparent material such as glass. One end of the outer tube 3 is integrally closed with a spherical part 4 having a substantially spherical shape, and the other end is left open, and the outer surface of the spherical part 4 has a light diffusion layer (not shown) as a preferable example. A membrane is applied. A disc-shaped glass stem 5 is hermetically sealed to the opening at the other end of the outer tube 3. Due to this sealing, the inside of the outer tube 3 is partitioned independently from the outside. A discharge space 6 is formed. For example, three luminous thin tubes 7, 8, and 9 are accommodated within this discharge space 6. The light emitting capillary tubes 7, 8, and 9 of this embodiment are straight glass bulbs that are bent into a substantially U-shape from the middle so that both ends are located adjacent to each other in the same direction.
The length from the curved portion 10 having a letter shape to one end is also longer than the length from the curved portion 10 to the other end,
and U-shaped luminous tubes 7, 8. Each straight line section 9 is formed to have a length that exceeds at least the Faraday dark section.

Further, on the stem 5 there is a lead wire 12. Three stem portions 20 supporting the electrode 1l are sealed via the stem 12, and each light emitting capillary tube is attached to the sealed portion between the stem portions 20 and the stem 5. ．． 8. 9 is sealed at one end.

With this sealing, the light emitting detail tubes 7, 8. 9 is
The curved part 10 is directed toward the spherical part 4, and the other end opening 16
The light emitting tubes 7, 8, 9 are fixed on the stem 5 in a posture facing toward the stem 5, and an electrode l1 is located at one end of each of the light emitting tubes 7, 8, 9. For this reason, inside the light emitting tubes 7, 8.9 there is a discharge path 13. whose side surface is approximately U-shaped. 14. 15 are formed, and these discharge paths 13. 14. 15 is each light emitting capillary 7, 8. 9 is communicated with the discharge space 6 through the other end opening l6. Luminous tube 7, 8. On the inner surface of 9 are phosphor coatings 17, 18, which emit monochromatic colors of red, green, and blue, respectively. 19 is on his back. Three light-emitting tubes are arranged in parallel, with a light-emitting tube 8 having a phosphor coating l8 that emits green light in the center.

On the other hand, luminescent tube 7. 8. On the stem 5 facing the other end opening l6 of the light emitting tube 7. 8.
9 discharge path 13. 14. One shared electrode 21 common to lead wires 23 . It is sealed via 23.

Further, a predetermined amount of gas mainly composed of mercury and a rare gas such as argon is sealed in the discharge space 6 through an exhaust pipe 22 led out from the stem 5, and after this filling, the exhaust pipe 22 is fused. sealed. The light sources 2 having such a configuration are closely arranged on the screen board 1 with the spherical portion 4 of the outer tube 3 facing the display side.

Thus, each light emitting tube 7, 8. The light bulb l1 of 9 and the common power source 21 are connected to a power source via a lighting device such as a ballast, and the light emitting tubes 7. 8. The discharge within 9 is caused by the power 11 sealed at one end and the shared power 2.
It is carried out between l. Note that although the discharge in this embodiment is performed by alternating current, it is of course possible to use direct current discharge. By controlling the lighting device with an image control unit such as a microcomputer, the number and position of the display elements 2 to emit light are changed according to the image signal.
Various images are displayed on the screen board 1.

In addition, a switch (not shown) is provided in the circuit connecting each power source 11 and the lighting device, and by selectively opening and closing this switch, the light emitting tubes 7, 8.9 that emit light change, and various light emitting Color is now available.

According to such a configuration, when a discharge occurs between the electrode l1 of each light emitting tube 7, 8, 9 and the common electrode l2, the light emitting tube 7. 8. 9 discharge path +3. 14. 15
Ultraviolet light is emitted from the sunlight column passing through the light emitting tubes 7, 8. 9 inner surface phosphor coating 17,
18. 19 to excite the phosphor, and each light emitting capillary 7. 8. 9 emits visible light of different colors. The visible light rays are then diffused by a diffusion film (not shown), and the respective colors are combined and radiated outward.

In this way, the light source 2 with the above configuration includes three luminous thin tubes 7, 8, and 8 inside the outer tube 3. By selecting light source 9 to emit light, the color of the emitted light can be freely changed even though the light source 2 is a single light source. Therefore, compared to the conventional case of combining three light sources emitting monochromatic red, blue, and green light, the number of light sources used can be reduced to 1/3, and the entire device can be made more compact.

Also, the number of electrodes 11 of the light source 2 and the lead wires 12. The number of 12 can also be reduced by using a shared electrode 21.

Furthermore, in the present invention, a luminescent tube that emits green light is arranged in the center. When green light is emitted, the entire display direction side of the outer tube 3 glows green, but when red or blue light is emitted, only one corner of the outer tube 3 glows, making it difficult to use the light effectively. On the other hand, among red, blue, and green lights, green light has the highest visibility. For this reason, if a light-emitting tube that emits green light is placed in the center, green light with high visibility can illuminate the entire display direction side of the outer tube, making it feel the brightest. If a light-emitting tube that emits blue or red light is placed in the center, the visibility of both will be low, giving the impression that the light source is insufficiently bright. That is, the arrangement of the light emitting tubes of the present invention allows the light source to feel bright.

Furthermore, in this example, monochromatic light emitting tubes of red, blue, and green were conventionally combined to produce a free color, so in order for a person to see a mixture of these monochromatic colors, a person would have to look at it from a considerable distance. However, in this example, one light source 2
Since the color mixing phenomenon occurs within the screen, the image quality of the screen is significantly improved.

In the above-described embodiment, the shape of the light-emitting capillary is approximately U-shaped, but it may be shaped like a straight tube, for example, and the number of light-emitting tubes is not limited to three.

Further, the low pressure mercury vapor discharge lamp of the present invention has at least blue,
Since it has luminous tubes that emit light in green and red, you can not only control the switching of the luminous tubes that emit light, but also adjust the amount of light emitted to emit light in blue, green, and red.
By combining these colors, any color can be created, including white.

Furthermore, although the above embodiment is described as a display light source used for a display screen, the present invention is not limited to this.
For example, a single tube can be used as a light source for displaying effects that emit light in three colors: blue, green, and red.

〔Effect of the invention〕

According to the present invention described in detail above, a plurality of light emitting tubes each having an electrode at one end and an open end at the other end are housed in a discharge space formed within a light-transmitting outer tube, and The inner surface is coated with a phosphor film that emits light of different colors, and the discharge space is filled with mercury and gas, and a single common light-emitting tube is provided for the discharge path of each light-emitting tube. Since a common electrode is provided, light emission of various colors can be obtained even though it is a single tube. Therefore, the number of light sources used can be reduced, as well as the number of electrodes and lead wires. Furthermore, in the present invention, since the green light-emitting tube is arranged at the center, the effect that the light source feels bright can be obtained.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a display screen, FIG. 4 is an enlarged view of the part ■ in FIG.
2 is an exploded perspective view of the light source, FIG. 2 is a sectional view of the light source, and FIG. 5 is a sectional view taken along the line V--V in FIG. 3...Outer tube, 6...Discharge space, 7. 8.
9... Luminous tube, 11... Electrode, 13. 14.
15...discharge path, +7. 18. 19... Phosphor coating, 21...
Shared electrode.

Claims (1)

[Claims] A discharge space airtightly partitioned and independent from the outside is formed within the translucent outer tube, and within this discharge space, three U-shaped light emitting tubes each having an electrode at one end and an open end are installed. The inner surfaces of these luminescent tubes are coated with phosphor coatings that emit blue, green, and red light, and the discharge space is filled with mercury and a rare gas. A low-pressure mercury vapor discharge lamp in which a single common power source is provided for the discharge path, wherein the three light-emitting tubes are arranged in parallel with a green light-emitting tube in the center. discharge lamp.