JPH0454340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a variable color discharge lamp device that can freely change the color of light.

(Background Art) FIG. 1 is a simplified diagram showing an example of a conventional variable color discharge lamp device, which includes fluorescent lamps 1a, 1b, and 1c whose emission colors are red, green, and blue, respectively.
and bidirectional three-terminal thyristors (triacs) 2a, 2b, 2c for controlling the phase and dimming the tube power of the fluorescent lamps 1a, 1b, 1c, respectively.
It consists of a series circuit of current-limiting stations 3a, 3b, and 3c, and each fluorescent lamp 1
The mixed light colors of a, 1b, and 1c are made variable. In addition, three color fluorescent lamps 1a, 1b, 1c
are usually covered with a diffusive globe 4 in order to improve the color mixing of their emitted colors.

However, in such a conventional variable color discharge lamp device, when trying to improve color mixing by using the diffusive globe 4, the transmittance decreases and the luminous efficiency as a light source decreases. On the other hand, if a globe with high transmittance is used, sufficient color mixing will not be achieved and the light emitted from the three color fluorescent lamps 1a, 1b, 1c inside the globe will be seen separately, making it insufficient as a variable color light source. It becomes a thing. In addition, three fluorescent lamps 1a,
1b and 1c constitute one light source,
Another drawback was that it was difficult to miniaturize the light source.

Furthermore, with the aim of unifying and downsizing the variable color light source, the applicant of the present application previously proposed a color discharge lamp and its control method that can freely select and control the light color (Japanese Patent Application No. 1983- No. 131593). This creates a discharge space that is airtightly formed by the outer tube and stem.
Contains three U-shaped inner tubes that are filled with Toor's rare gas and mercury vapor and each have a similar shape and are coated with phosphors of different luminescent colors (for example, the three primary colors of red, green, and blue). One end of each inner tube is hermetically fixed around three electrodes arranged on the stem, and the other end is fixed in the vicinity of another common electrode arranged on the stem. It is arranged to open. However, this color discharge lamp also has the drawback that sufficient color mixing cannot be obtained, similar to the conventional example.

(Objective of the Invention) The present invention has been made in view of the above points, and its purpose is to provide a variable color emitting device that can freely change the emitted color with one light source and has good color mixing properties. To provide electric lighting equipment.

(Disclosure of invention) The present invention will be explained below based on examples.

FIGS. 2 and 3 show an embodiment of the variable color discharge lamp used in the present invention, which includes an outer bulb 5 and two stems 6a and 6b hermetically sealed at both ends of the outer bulb 5.
Several Torr of rare gas and mercury are sealed in the airtight space formed by the above, forming a discharge space. There are three anodes 7 on one of the stems 6a.
a, 7b, and 7c are arranged, and a common cathode 8 is arranged on the other stem 6b. It is preferable that the anodes 7a, 7b, and 7c are arranged so that each anode is located at the apex of an equilateral triangle, as shown in FIG. 3a. One ends of the two inner tubes 9a and 9b arranged in the airtight space are arranged around the anodes 7a and 7b in an airtight manner (meaning airtightness to the extent that discharge does not crosstalk between adjacent electrodes, and gas-tightness is ensured). (not necessarily airtight), and the other end opens into an airtight space. A blue phosphor 1 is provided on the inner surface of the outer tube 5.
0B, and red and green phosphors 10R and 10 are applied to the inner or outer surfaces of the inner tubes 9a and 9b, respectively.
G is coated. Further, a reflective film 11 is formed on the inner tube side half circumferential surface of the outer tube 5 as necessary. As the phosphor, it is preferable to use europium-activated yttrium oxide for red, terbium-activated cerium magnesium aluminate for green, and europium-activated barium magnesium aluminate for blue.

FIG. 4 shows a circuit configuration for controlling lighting of the variable color discharge lamp according to the present invention, in which each anode 7a, 7
Switch elements T1, T2, T, such as transistors, correspond to the respective discharge paths 12R, 12G, 12B formed between the common cathode 8 and the common cathode 8.
3 and current limiting resistors R1, R2, and R3 are connected. In addition, C in the figure represents each of the above-mentioned switch elements T1 and T.
2. A control circuit that controls the on-duty of T3, DC is a direct current power supply, and S is a power switch.

Next, the operation will be explained. Now, when the power switch S is turned on, a current flows through the common cathode 8, sufficiently heating the filament constituting the cathode 8, and bringing it into a state where it emits sufficient thermoelectrons. When the power switch S is turned off in this state, a power supply voltage is applied (note that a base current is applied to each switch element T1, T2, and T3 from the control circuit C in advance to turn them on), and each discharge path 12R, 12G,
12B starts and lights up. Next, the on-duty of each switch element T1, T2, T3 is changed, for example, as shown in FIG.
By controlling the discharge current ratio to R, 12G, and 12B and changing the intensity of each emitted light color, the overall light color can be freely changed to a desired color.

That is, to explain using the example shown in FIG. 5, in (a), the discharge path 12R, that is, the inner tube 9a coated with the red phosphor 10R, emits strong light and becomes reddish,
In (b), the discharge paths 12R, 12G, and 12B emit light uniformly and are substantially white. In (c), the discharge path 12G emits light of a strong green color; in (d), the discharge path 12B emits light of a strong blue color; and in (e), the discharge paths 12R and 12G emit light equally and has a substantially yellow color.

In this way, the lamp current itself as a whole is always constant, and the cathode 8 is kept at a constant temperature, which is preferable from the viewpoint of lamp life, and there is no phenomenon such as turning off when the discharge path is switched. Stable discharge migration and discharge fibers are created. moreover,
Regarding color mixing of light, when the inner tubes 9a and 9b are arranged and the reflective film 11 is formed as shown in the above embodiment, the colors are mixed uniformly throughout the direction in which light is desired to be distributed as shown in FIG. In addition, since the red-green color that is the mixed color of both inner tubes 9a and 9b is superimposed on the blue light emitted from the 5 surfaces of the outer tube, the unevenness of light is much improved and the degree of uniformity is improved. .

It should be noted that the present invention is of course not limited to the above-mentioned embodiments. For example, by arranging the inner tube in a planar manner and making the outer tube into a shape with a flat tube cross section, it is possible to create a variable flat plate type. A color discharge lamp device can be provided. Alternatively, the inner tube may be formed into a U-shape as described in the background art section, and a bulb-shaped variable color discharge lamp may be used. Further, the anodes 7a and 7b in the above embodiment are connected to the stem 6a.
Although the structure is such that the inner tubes 9a and 9b are fixed in an airtight manner around the inner tubes 9a and 9b, it goes without saying that the present invention is not limited to such a structure.
The point is that one end of the inner tube opens into the discharge space, and the electrode is disposed inside the other end, that is, the closed end (closed here does not necessarily have to be gas-tight closed as described above). Bye. If an airtight space can be formed only by the outer tube, the stem is not necessarily necessary, and therefore, the other anode 7c and the common cathode 8 may be arranged at appropriate positions within the outer tube.

(Effects of the Invention) By configuring the present invention as described above,
The lamp can freely change the emitted color with one light source and has good color mixing properties, and the lamp has no negative effect on the lamp life, and there is no phenomenon such as fading when the discharge path is switched, and the discharge is stable. A variable color discharge lamp device capable of transition and discharge maintenance can be provided.

[Brief explanation of the drawing]

FIG. 1 is a simplified diagram showing an example of a conventional variable color discharge lamp device, and FIGS. 2 and 3 are simplified diagrams showing an example of a variable color discharge lamp used in the present invention.
The figure is a perspective view, FIG. 3a is a sectional view, FIG. 3b is a side view, FIG. 4 is a circuit configuration diagram for controlling lighting of the variable color discharge lamp according to the present invention, and FIGS. 5a to 5e are same as above. The time chart, FIG. 6, is a light distribution diagram according to the present invention. 5...Outer tube, 6a, 6b...Stem, 7a, 7
b, 7c... Anode, 8... Common cathode, 9a, 9b
...Inner tube, 10R...Red light emitting phosphor, 10G...
...Green light emitting phosphor, 10B...Blue light emitting phosphor,
11... Reflective film, 12R, 12G, 12B... Discharge path.

Claims (1)

[Claims] 1 Inside an outer tube whose inner surface is coated with a blue-emitting phosphor, two inner tubes with one end open and whose tube walls are coated with red and green phosphors are disposed, and each of the inner tubes is A variable color discharge lamp comprising a discharge path formed between an anode disposed inside the closed end side of the lamp, an anode disposed within the outer bulb, and a common cathode disposed within the outer bulb, and a lamp of the lamp. A variable color discharge lamp device comprising a lighting device which changes the color of the light as a whole by changing the discharge current ratio of each discharge path while keeping the current constant at all times.