JPS6149366A - Variable color fluorescent lamp - Google Patents

Abstract

PURPOSE:To make the luminous color of a single lamp variable readily, by placing phosphors of different luminous colors, over the inner surface of an outer bulb, and the inner and outer surfaces of the inner bulb housed therein, so as to make up a set of discharge line and mix up the luminous colors. CONSTITUTION:While a rare gas ans mercury are sealed in an air-tight room between an outer bulb 5 and a stem 6, a pair of electrodes 7 and 8 are arranged on the stem 6. And, an inner bulb 9 enclosing one of the electrodes 7 on the one end is furnished to make up a set of discharge line H. Furthermore, over the inner surface of the outer bulb 5, and over the inner and outer surfaces of the inner bulb 9, phosphors 10a and 10b which are of different luminous colors and different luminous intensity factors against input power, such as halo-calcium phosphate phosphor and a rare earth type phosphor, are applied to make a fluoresent lamp. Thus, by controlling the lamp input power through a variable impedance VZ in the lighting circuit, a variable color fluorescent lamp with an output luminance of mixed colors can be acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Section'EF) The present invention relates to a variable color fluorescent lamp that can freely change the color of light.

(Background Technique 1) Fig. 1 is a simplified diagram showing an example of a conventional variable color discharge lamp device, and this device includes fluorescent lamps Ia, lb, and lc whose emission colors are red, it color, and blue, respectively. The fluorescent lamp la,
Bidirectional two-terminal triac 2a, 2 for phase control and polarization of lb and lc tube power, respectively
b, 2c, and current-limiting chokes 3a, 3b, 3c, each fluorescent lamp 1a, 1b,
The mixed light color of the LC is made variable. Note that the three-color fluorescent lamps la, lb, and lc 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 contrary, a globe with high transmittance is used. , sufficient color mixing was not obtained, and the three color fluorescent lamps la, lb, l in the glove
The emitted light of c is seen separately, making it insufficient as a variable color light source. In addition, three fluorescent lamps 1a, 1
B and LC constitute one light source, which has the disadvantage that it is difficult to miniaturize the light source. (Objective of the Invention) The present invention has been made in view of the above points, and The object of the present invention is to provide a variable color fluorescent lamp that can freely change the color of emitted light using a single light source.

(Disclosure of the Invention) The present invention provides a low-pressure discharge lamp comprising at least one pair of electrodes disposed within a tube enclosing mercury and a rare gas, and a series of discharge paths is formed between the electrodes. A plurality of phosphors emitting light of different colors are arranged along the discharge path, and the light emitted from the plurality of phosphors is mixed. n
It is characterized by using colored light as output light.

Hereinafter, the present invention will be explained based on examples.

Embodiment 1 FIG. 2 shows a first embodiment of the variable color fluorescent lamp according to the present invention, in which several Torr of rare gas and mercury are contained in the airtight space formed by the outer tube 5 and the stem 6. is enclosed,
It forms a discharge space. Two electrodes 7 are placed on the stem 6.
．． 8 are arranged.

One end of the inner tube 9 disposed in the airtight space is airtight around the one electrode 7 (airtight to the extent that discharge does not crosstalk between adjacent electrodes, and gastight). ), and the other end opens into an airtight space.

The inner surface of the outer tube 5 and the inner or outer surface of the inner tube 9 are coated with phosphors 10a and 10b that emit light of different colors, respectively.

Next, the operation of this embodiment will be explained. Now, when the variable color fluorescent lamp according to the present embodiment lfi is turned on via a known lighting device, a discharge path shown by an arrow line H in FIG. 2 is formed. The ultraviolet light generated from the discharge path excites the phosphor 10a in the section inside the inner tube 9, and similarly excites the phosphor 1Ob in the section outside the inner tube 9. That is, a series of discharges excites two types of phosphors depending on the section. The light emitted from the phosphor 10a passes through a layer of phosphor 10b applied to the inner surface of the outer tube 5 and exits the tube. Therefore, mixed color light, in which the light emitted from both the phosphors 10a and 10b are integrated, is output to the outside of the tube.

By the way, generally as the input to the phosphor increases,
Emission intensity also increases. However, it is well known that when the input exceeds a certain value, saturation of the emission intensity occurs due to factors such as the temperature quenching characteristics of the phosphor. The degree of saturation varies greatly depending on the type of phosphor.9 For example, as shown in Figure 3, the widely used calcium halophosphate phosphor A has a higher degree of saturation than rare earth phosphors. (The amount of spray is significant.

Therefore, as shown in FIG. 4, a lighting circuit consisting of an electric aAc, a variable impedance VZ, and a glow starter G is connected to the variable color fluorescent lamp so that the input to the lamp can be controlled. Then, on the inner surfaces of the outer tube 5 and the inner tube 9,
They each have different emission intensity characteristics (indicated by E in the figure) as shown in Figure 5, and have emission colors corresponding to D' and E' on the chromaticity coordinates shown in Figure 6. Two types of fluorescent materials are used. Thus, the input to the lamp by the lighting circuit is changed to F-G in FIG.
-H increases, the emission intensity ratio of the phosphor with characteristic E to the phosphor with characteristic E decreases,
The emitted light color changes as F"-G'-H' on the chromaticity coordinates shown in Fig. 6. In other words, the input to the lamp is
By adjusting between F and H in the figure, the emitted light color can be changed to any value on the straight line connecting Fo and H on the chromaticity coordinates shown in FIG.

In this way, in this embodiment, the inner surface of the outer tube 5 and the inner or outer surface of the inner tube 9 are coated with phosphors that emit light of different colors and have different emission intensity characteristics with respect to input. Since the phosphor is excited in the discharge path of the vehicle, it is possible to provide a variable color fluorescent lamp that has very good color mixing properties by controlling the input to the lamp and is capable of brightening.

Note that the means for forming a series of discharge paths is not limited to the above-mentioned embodiment, and for example, a structure as shown in FIG. , three electrodes as shown in Figure 8? a, 7b, 7
Three discharge paths H1, H2, H3 formed by c and the common electrode 8
and each discharge path H1, H2', H3 is formed by a lighting circuit.
It is also possible to switch between the two. In addition, Figures 7 and 8
A description of the configuration shown in the figure will be omitted by assigning the same reference numerals to the same components as in the previous embodiment. Further, in FIG. 8, 11 is a partition plate.

Embodiment 2 FIG. 9 shows a second embodiment of a variable color fluorescent lamp according to an uninvented invention, which is composed of an outer tube 5 and two stems 6a and 6b hermetically sealed at both ends of the outer tube 5. A rare gas of several Torr and water are sealed in the airtight space to form a discharge space. On one of the above stems 6a, there are two electric terminals +E.
ig7a, 7b are provided, and a common electrode 8 is also provided. Two inner pipes 9a arranged in an airtight space
, 9b are airtightly placed around the electrodes 7a, 7b.
Adjacent electrodes are fixed in a gas-tight manner (meaning air-tight to the extent that discharge does not talk, but do not need to be gas-tight),
The other end opens into an airtight space. The inner surface of the outer tube 5 and the inner or outer surfaces of the inner tubes 9a and 9b are coated with phosphors (not shown) that emit light of different colors.

FIG. 10 shows a circuit configuration for controlling the lighting of the variable color fluorescent lamp as described above, which includes a series circuit of the variable color fluorescent lamp FL, the discharge path changeover switch 3w, the current limiting choke L, and each of the electrodes 7a. , 7b.

On the non-power side of 8 and between two pairs of electrodes facing each other (electrode 7
A glow starter G is connected between the electric current piA 7b and the electrode 8, and between the electric piA 7b and the electrode 8), and by switching the switch 3w, the discharge path is changed and the light color is changed. Note that AC in the figure is an alternating current power source.

So, switch 3W has 10,000 m poles? When connected to the a side, a discharge occurs from the electrode 17a through the inside of the inner g9a and between the common electrode 8, and the color of the emitted light is the same as that of the phosphor applied to the inner surface of the inner tube 9a and the outer tube. When the switch 5w is connected to the other electrode 7b side, a discharge occurs between the electrode 7b, the inside of the inner tube 9b, and the common electrode 8. The emitted light color is a mixture of the emitted color of the phosphor applied to the inner surface of the inner tube 9b and the emitted color of the phosphor spread on the inner surface of the outer tube 5, resulting in a two-stage variable color light source. becomes.

In this way, in this example, two different colors of emitted light can be obtained with a simple configuration. Furthermore, since the configuration is such that the color of light emitted by the outer tube is superimposed on the color of light emitted by the inner tube, good mixed color light can be obtained without the need for a conventional diffusion globe. Although the above embodiment has been described with reference to the case where there are two inner tubes, the number of inner tubes is not limited to two, and it goes without saying that the discoloration level increases as the number of inner tubes increases. As shown in the figure, a configuration may be adopted in which a discharge path between both electrodes 7a and 7b is added, and a total of three discharge paths are selected.

Embodiment 3 FIG. 12 shows a third embodiment of the variable color fluorescent lamp according to the present invention, in which one end is disposed on the stem 16 in a discharge space airtightly enclosed by an outer tube 15 and a stem 16. A plurality of (four) inner tubes 19a to L9d are hermetically fixed around the electrodes 17a to 17d to be provided, and the other end is open. A different phosphor (not shown) is applied, and an outer g1
This is a fluorescent lamp in which the inner surface of the lamp 5 is also coated with fluorescent material. In this embodiment, a discharge path passing through any two inner tubes is formed, and the color of the emitted light at that time is a mixture of the colors emitted by the phosphors coated on the two inner tubes 19 and the outer tube 15. Become. As shown in FIG. 13, if a reflective film 20 is applied around P1 of the outer tube 15, it is possible to cover the portion (which does not contribute to light emission) and also to increase the light emission to the front surface. be.

Implementation (114) FIG. 14 shows a fourth embodiment of the variable color fluorescent lamp according to the present invention, in which a cylindrical outer part 925 and stems 26a, 26
This is a fluorescent lamp in which two inner tubes 29a and 29b are housed in a discharge space that is airtightly closed by a tube b.
, 29b are arranged such that their respective central axes are slightly offset from the central axis of the outer tube 25, and each of the inner tubes 29a, 29b
One end of 9b is an electrode 27 disposed on one stem 26a.
a.

27b, and the other end is open near the other stem 26b. Also, one other electrode 2
7c is a stem 26 between the outer tube 25 and the large diameter inner tube 29b.
It is arranged on a. The inner surfaces of the outer tube 2S and each of the inner tubes 29a and 29b are coated with phosphors of different luminescent colors.

In this embodiment as well, as in the case shown in FIG.
7c, electrodes 27b to 27C form five missing current paths, and the respective emitted light colors are mixed. In this case, since the outer tube 25 and the two inner tubes 29a and 29b are configured in an eccentric cylindrical shape, the color mixing property is further improved compared to the embodiment shown in FIG. 9.

In addition, in the embodiment shown in FIGS. 9 and 14),
By applying a reflective film to approximately half the circumference of the outer bulb on the side where the discharge path is not formed, it is possible to cover the part that does not contribute to light emission.
This has the advantage that the light emission output can be increased and color mixing properties can be further improved. Further, it goes without saying that if a diffusion layer is formed on approximately half the circumferential surface on the side where the reflective film is not applied, the color mixing property can be further improved.

Example 5 A fifth example 1311 is a variable color fluorescent lamp according to the second example (11), in which the two electrodes 7a and 7b are anodes, and both electrodes 7a and 7b are anodes.
The ff1 electrode 8 is used as a cathode, and the other configurations are the same.

FIG. 15 shows the lighting circuit of this embodiment, which is composed of a series circuit of a current limiting resistor R and a direct current power source DC. FIG. 16 is an example of a time chart showing the operation of the above circuit, with period T(
T4 to T4) are divided into two: a discharge from one anode 7a through the inner tube 9a to the cathode 8, and a discharge from the other anode 7b through the inner tube 9b to the cathode 8. and,
By changing the division ratio, the luminous intensity ratio of both discharges is changed and the hue is changed. The figure shows four cases with different emission ratios.

With this configuration, a constant current always flows through the cathode 8 regardless of the hue, and the cathode 8 is brought to an appropriate temperature, so the lamp life is not adversely affected and the discharge is reduced. Since the color changes by changing the time ratio, the response to color change is extremely fast. moreover,
The emitted light color (mixed color) can be freely selected from a mixture of the intermediate color of the emitted light from both inner tubes 9a and 9b and the emitted color from the outer tube 5. Note that in this embodiment as well, the number of inner tubes is not limited to two, but may be a plurality of inner tubes.
The only difference is the number of divided discharge paths shown in FIG. 6, and the other operations are the same.

FIGS. 17 and 18 show specific examples of the lighting circuit, in which the discharge level changeover switch 5w is composed of PNP L-transistors Trl and Tr2, and the DC power supply DC is connected to a control circuit power supply DCI and a main circuit power supply DC2. It is composed of The specific example shown in FIG. 18 is an example using the variable color fluorescent lamp FL as shown in FIG. 14, and the zero circuit operation is almost the same as described above.

As described above, in this embodiment, the emission color ratio of the plurality of inner tubes can be freely set without deteriorating the initial characteristics such as color change responsiveness. Therefore, the variable color level increases, and fine hue settings can be made. For example, if the outer tube is coated with a phosphor that emits white light, and the two inner tubes are coated with phosphors that emit green and red, respectively, the second embodiment can produce white light. 2: greenish green and whitish red (pink)
Whereas previously it was only possible to switch colors, you can now set colors intermediate between the two (for example, a natural yellow) in fine grain.

(Effects of the Invention) As described above, the present invention comprises disposing a small number of electrodes (at least one pair) in a tube such as an outer tube that encloses mercury and a rare gas, and forming a series of discharge paths between the electrodes. In the low-pressure discharge lamp, a plurality of phosphors emitting light of different colors are arranged along the series of discharge paths, and the light emitted from the plurality of phosphors is mixed to produce the mixed color light. It is characterized by output light, and multiple phosphors are excited and emit light in a single discharge path, and the emitted light is output outside the tube as mixed color light, so one lamp We were able to provide a variable color fluorescent lamp that can freely change the color of the emitted light with an extremely simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a conventional variable color discharge lamp device;
FIG. 2 is a simplified sectional view showing the first embodiment of the present invention, FIG. 3 is a diagram showing the emission intensity characteristics of the phosphor with respect to input, FIG. 4 is a circuit configuration diagram according to the first embodiment, and FIG. The figure is a light emission intensity characteristic diagram of the phosphor according to the first embodiment, FIG. 6 is a chromaticity diagram according to the first embodiment, and FIGS. 7 and 8 are simplified diagrams showing modifications of the first embodiment, respectively. 9 is a simplified perspective view showing the second embodiment of the present invention, FIGS. 10 and 11 are circuit configuration diagrams according to the second embodiment, and FIG. 12 is a schematic perspective view showing the second embodiment of the present invention.
FIG. 13 is a simplified perspective view of an outer tube according to a third embodiment, FIG. 14 is a simplified perspective view of a fourth embodiment of the present invention, and FIG. 15 is a simplified perspective view of an outer tube according to a third embodiment. A circuit configuration diagram according to the fifth embodiment, FIG. 16 is a time chart example showing the operation of the same circuit as above, and FIGS. 17 and 18 are specific examples of the lighting circuit according to the fifth embodiment.

Claims (4)

[Claims] (1) In a low-pressure discharge lamp, in which at least one pair of electrodes is disposed within a tube that encloses mercury and a rare gas, and a series of discharge paths is formed between the electrodes, along the series of discharge paths, A variable color fluorescent lamp characterized in that a plurality of phosphors emitting light of different colors are arranged, the light emitted from the plurality of phosphors is mixed, and the mixed color light is used as output light. (2) The variable color fluorescent lamp according to claim 1, wherein the series of discharge paths are formed in the tube and in an inner tube with an open end disposed within the tube. (3) By arranging multiple inner tubes within the tube body,
3. The variable color fluorescent lamp according to claim 2, wherein a plurality of said series of discharge paths are formed. (4) The inner surface of the tubular body and the inner tube are coated with phosphors that emit light of different colors and have different emission intensity characteristics with respect to input. Variable color fluorescent lamp as described.