JPH05135744A - Variable-light color fluorescent lamp and lighting method thereof - Google Patents

Abstract

PURPOSE:To provide the phosphors and pulse lighting condition changing the light quantity ratio between blue luminescence and red luminescence. CONSTITUTION:At the time of the pulse lighting of a xenon-sealed fluorescent lamp or a xenon and mercury-sealed fluorescent lamp coated with multiple kinds of phosphors providing luminescence in nearly the whole visible area, its duty ratio or the pulse width is adjusted to change the light color of the single lamp. The lamp light color is similar to the conventional three-wavelength type, thus a comfortable illumination light source having an excellent color rendering property and capable of changing the light color without replacing the lamp in response to the cold, hot, dry, or wet weather is obtained. When xenon is used for the filler gas, there is no fear of environmental pollution caused by its disposal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source for comfortable lighting and a lighting method thereof, which can change the light color of a single fluorescent lamp in accordance with the ambient environment such as cold, dry and humid conditions and the sensation of the user of the lamp.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 53-42386 discloses a discharge display device which changes the color of light of a single lamp. Each visible light emission of two or more types of discharge is switched and displayed by controlling the current waveform. In the neon + mercury system, pink and bluish white can be switched and displayed depending on the difference in ionization voltage.

Japanese Unexamined Patent Publication (Kokai) No. 3-71551 discloses a single-ended compact variable light color lamp and a lighting device in which two kinds of phosphors for ultraviolet ray excitation and electron beam excitation are coated on the inner surface. In this lamp, the cathode and anode are placed at a maximum distance of several cm, and the electron flow is controlled by adjusting the voltage applied between both electrodes.When the voltage is low, mercury vapor discharge occurs, and when the voltage is high, the cathode line gives priority to the phosphor. Excite. Therefore, the emission color peculiar to each phosphor can be obtained.

Japanese Unexamined Patent Publication (Kokai) No. 2-256197 discloses a device for lighting a xenon-filled fluorescent lamp with a half-wave rectified voltage having a frequency of 4 KHz or more and 200 KHz or less.

Japanese Unexamined Patent Publication (Kokai) No. 58-21293 discloses a driving method of a high efficiency gas discharge light emitting device utilizing Townsend discharge light emission which is excessively generated at the start of discharge.

On the other hand, Japanese Patent Publication No. 57-353 is used for a light emitting device equipped with a highly efficient blue phosphor for rare gas discharge, and Japanese Patent Publication No. 57-352 is used for a light emitting device equipped with a highly efficient red phosphor.
There are some issues, and all of them are useful when applied to the gas discharge light emitting device.

[0007]

[Problems to be Solved by the Invention] The Japanese Patent Publication No. 53-4238
The device of No. 6 is excellent for switching the light color of the display, but since the light color has a chromaticity point far from the black body locus on the chromaticity diagram, the average color rendering index is low, and There is a drawback that the invention is not suitable for the purpose of comfortable lighting.

Further, the device of Japanese Patent Laid-Open No. 3-71551 can change the lamp light color by using a control circuit which is inexpensive and has little noise, but in order to obtain a uniform light emission locally by electron beam excitation, a spheroid is used. There are naturally restrictions on the shape of the lamp, such as the appropriate shape.

On the other hand, Japanese Unexamined Patent Publication No. 2-256197 discloses an OA as an aperture type fluorescent lamp having a reflecting film with a slit.
Even if it is useful as a device, it is difficult to obtain a variable light color because it lights with a half-wave rectified voltage. Lighting with the half-wave rectified voltage corresponds to a duty ratio of about 50% described later.

Japanese Unexamined Patent Publication (Kokai) No. 58-21293 is an excellent method for a plasma display including minute discharge cells, but the luminous flux is insufficient for use in illumination. Similarly, Japanese Patent Publication Sho 57
The blue phosphor and the red phosphor disclosed in the devices of -353 and Japanese Patent Publication No. 57-352 are different inventions in that they are intended for displays even though their chemical compositions are similar to those of the present invention.

[0011]

With the xenon-encapsulated fluorescent lamp according to the present invention, in converting the ultraviolet light generated by discharge into visible light, a blue phosphor and a red light that are mixed and applied among the light emission in the entire visible range. A phosphor having a relatively different rise and decay characteristic of light emission is selected, and a duty ratio of 10% or more 5
By adjusting within the range of less than 0%, the light quantity ratio of blue light emission and red light emission is changed to change the light color of a single lamp.

More preferably, the xenon resonance line 147n
blue phosphor YP ₀ high efficiency for excitation of vacuum ultraviolet light including a _{m. 85 V 0. 15 O} 4, Y 0. 9 Gd 0. 1 P 0. 85 V 0. 15 O 4, B
aMg ₂ Al ₁₆ O ₂₇ : Eu, BaMgAl ₁₄ O ₂₃ : E
u, Y ₂ SiO _5: at least one selected from Ce, similarly red phosphor YP high efficiency _{0 65 V 0 35 O 4:} .. Eu, Y 2
At least one selected from O ₃ : Eu and Gd ₂ O ₃ : Eu is used, and an appropriate amount of both is mixed and applied.

When the duty ratio is close to the above lower limit value, a constant voltage is applied between both electrodes in advance to cause light emission, and then a pulse is superposed on this voltage so that a sufficient luminous flux can be obtained. Realize the light color.

On the other hand, in a fluorescent lamp in which other rare gas and mercury are sealed in addition to xenon gas, depending on the amount of space charge generated in the lamp, a small pulse width results in 1 xenon discharge.
47 nm light is strong, and with a large pulse width, 254 nm light due to mercury vapor discharge is strong. Therefore, by mixing and applying a highly efficient phosphor for each wavelength, for example, even if the duty ratio is the same within the regulated range, if the pulse width is small, Townsend discharge or glow is generated depending on the width. The 147 nm photoexcitation based on discharge preferentially intensifies the blue light, and when the pulse width is large, the 254 nm photoexcitation based on glow discharge or arc discharge preferentially enhances the red light. As a result, a variable light color depending on the pulse width is obtained.

By accessing a magnetic card or an IC card in which pulse width, repetition period, pulse voltage, positive / negative polarity switching, etc. are recorded in advance, the number of changeover switches can be reduced and the light color changing operation can be simplified. ..

[0016]

The operation of the present invention will be described with reference to FIGS. In FIG. 1, a pair of electrodes 2a,
2b face each other, and xenon gas 3 is enclosed. On the inner wall of the tube body 1, a phosphor 4 that converts 147 nm light generated by the discharge of xenon 3 into visible light is applied. The phosphor 4 is different from the conventional three-wavelength band emission type fluorescent lamp in that it has high efficiency for 147 nm light and uses a blue phosphor and a red phosphor having different emission transient characteristics. After preheating 2b with the preheating power source 5, the pulse power source 6
Then, a pulse voltage is applied through the series resistor 7 to discharge the xenon gas 3.

Next, the pulse power supply 6 is adjusted to change the duty ratio, and the brightness of the central portion of the tube 1 is measured. Here, the duty ratio D is expressed as a percentage of a value obtained by dividing the pulse width W by the repetition period T, that is, D = (W / T) × 100. FIG. 2 shows pulse voltages V of 220V, 240V, 26.
It is an example of the relationship between D and the brightness of the central portion of the tube when the voltage is 0V. Here 4, blue phosphor YP _{0. 85} V _{0. 15}
O ₄ only to be. Although the brightness increases as V increases, the brightness when D = 50 is shown as 1 regardless of V in the figure. From the figure, the brightness increases monotonically with a decrease in D 10
It can be seen that the maximum brightness is obtained in the region of ≤D≤20.
Even if 8 ≦ D <10, sufficient luminance can be obtained, but the discharge is slightly unstable. The area of D where the maximum brightness is obtained even when only the red phosphor is used for 4 is the same, but the shape of the curve in 10 ≦ D ≦ 20 is different. As described in the examples, the difference in the curve shape depending on the phosphor composition is a light color variable factor.

Another effect of the present invention is that it is highly efficient for vacuum ultraviolet light excitation including the xenon resonance line of 147 nm and that sufficient brightness can be obtained for general illumination. Furthermore, the luminescent ions of the blue phosphor are trivalent VO ₄ ,
It is composed of divalent Eu and trivalent Ce, and the emission decay time is fast in this order, whereas the red light-emitting ions are all trivalent Eu, and the decay time is longer than that of the blue light-emitting ion group. It is slow, and accordingly, the light amount ratio of both light emission can be changed under pulse lighting.

Further, by superimposing the bias light, it is possible to secure sufficient brightness. Furthermore, due to the presence of mercury vapor, the pulse width W = 0.2 μs,
The period T = 2 μs and W = 1 μs, T = 10 μs are both D =
10 is given, but the discharge mode is different, so the former is 14
7 nm light, the latter 254 nm light is strong, and the light color changes by coexisting a highly efficient blue or red phosphor for each excitation wavelength. Here, a rare gas other than xenon, such as helium or neon, is useful for adjusting the lighting voltage.

Although the characteristic of the lamp of the present invention is that the light color changing operation is simple, as described above, if necessary, a plurality of resistors having different resistance values are previously arranged in the resistor 7 of FIG. Then, it is also useful for operations such as selecting one of them.

[Example 1] Outer diameter 15.2 mm, wall thickness 0.6 m
m, glass tube of 280 mm in length, blue phosphor YP ₀ .
. ₈₅ V _{0 15} O ₄ and the red phosphor _{YP 0 65 V 0 35 O 4} :.. Eu a weight ratio of 1: mixture was applied at 1 to prepare a hot-cathode fluorescent lamp 8W filled with xenon gas 1Torr .. 2 in FIG.
After preheating by supplying 100 mA to b, a rectangular wave pulse having a pulse width W = 1 μs, a repetition period T = 2 μs, and a voltage V = 220 V was applied to 7 by using 22 KΩ, and lighting was performed. This pulse condition corresponds to a duty ratio D = 50. Next, when the repetition period T was changed while V and W were kept constant, a D vs. tube central portion luminance characteristic similar to FIG. 2 was obtained. Further, the emission spectrum of the lamp was measured while changing D, and the ratio of the blue emission amount at the peak wavelength of 450 nm to the red emission amount at the peak wavelength of 620 nm, that is, B / R ratio was calculated from the emission spectrum. Assuming that the B / R ratio at D = 50 is 1, D
FIG. 3 is a plot of the relationship between B and R ratio. As is clear from the figure, the B / R ratio reached a maximum of 1.56 in the region of 10 <D <20. This means that the blue light emission amount can be increased by changing only the repetition period T while keeping the pulse voltage V and the pulse width W fixed.

Table 1 shows the composition of phosphors of blue and red pairs and B.
The relationship with the / R ratio is shown collectively. From the table, it was confirmed that the B / R ratio exceeds 1 even when any pair of phosphors are mounted on the lamp, that is, the lamp light color changes depending on the duty ratio D. Same is, Y ₀ blue phosphor. _{9
... Gd 0 1 P 0} 85 V 0 15 O 4, BaMgAl 14 O 23: Eu,
A pair using Gd ₂ O ₃ : Eu as the red phosphor was also confirmed. The reason that the B / R ratio is relatively small when the blue phosphor Y ₂ SiO ₅ : Ce is used is that the rising and decay times of light emission are the fastest among the phosphors in the table. Further, the B / R ratio at the duty ratio D = 50 is
It is not necessary to set the same 1 as in FIG. 3 and Table 1, and it can be freely selected by changing the mixing ratio of the blue phosphor and the red phosphor.

[0023]

[Table 1]

[Embodiment 2] In order to realize a lamp light color suitable for comfortable lighting, at least a green phosphor is required in addition to the phosphor shown in Embodiment 1. Therefore, the well-known green phosphor (La, Ce) PO ₄ : Tb and Zn ₂ Si
An 8 W xenon lamp similar to that of Example 1 in which O ₄ : Mn was separately applied was prepared, and the brightness of the central part of both tubes was compared. When both the amounts of the attached phosphors are 0.5 g / piece, the duty ratio D vs. the brightness characteristics of the central part of the tube are similar to those in FIG.
Relative brightness at the same duty ratio is 100,
The value was almost equal to 103. This phenomenon is
In contrast, the B / R ratio of γ depends on the phosphor composition of the pair. From the observation of the emission waveform under pulse lighting, the emission decay time of the green phosphor used here is on the order of several ms, the decay time is longer than that of the phosphor exemplified in Example 1, and it is not sensitive to changes in the duty ratio. I confirmed that there is no.

[0025]

As described above, according to the present invention, there is an effect that the light quantity ratio of blue light emission and red light emission of the visible light emission of the xenon gas filled fluorescent lamp can be changed by adjusting the duty ratio. This effect is maintained even if the green light emission of the order of ms of light emission decay is superposed on the wavelength region between the two light emission. Therefore, in the three-wavelength light emission type fluorescent lamp filled with xenon gas, the light color is changed to, for example, It is possible to change from light bulb color to white, or from neutral white to daylight color. In addition to xenon gas, other rare gas and mercury are sealed to change the pulse width to 147 nm and 254 nm.
If the phosphors for nm are switched to emit light, there is an effect that a variable light color can be similarly obtained. Visible light emission consisting of three wavelength bands has a relatively high average color rendering index and is useful as a light source for comfortable illumination. Further, if the card in which the pulse conditions are recorded is accessed when the lamp is turned on, there is an effect that the variable light color operation is simplified. The xenon gas-filled fluorescent lamp described above has a great effect that it is discarded because it is silver-free and there is no risk of pollution.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a lamp of the present invention and a method of lighting the lamp.

FIG. 2 is a characteristic diagram illustrating the operating principle of the present invention.

FIG. 3 is a characteristic diagram illustrating an example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Translucent tube, 2a, 2b ... Electrode, 3 ... Xenon gas, 4 ... Phosphor, 5 ... Preheating power supply, 6 ... Pulse power supply, 7
… Series resistance.

Claims (5)

[Claims] 1. A xenon gas-filled fluorescent lamp comprising at least a pair of electrodes and a translucent tube having an inner surface coated with a plurality of types of phosphors that emit light in the substantially visible region when excited by ultraviolet rays. Among them, the phosphor that emits light in the blue region and the phosphor that emits light in the red region have relatively different rising and decay characteristics of light emission, and at the time of pulse lighting of the fluorescent lamp, a percentage of the value obtained by dividing the pulse width by the repetition period. A variable light color fluorescent lamp characterized in that the light color of a single lamp is changed by changing the light amount ratio of blue region light emission and red region light emission by adjusting the duty ratio represented by 10% to less than 50%. Lighting method. 2. A xenon gas-filled fluorescent lamp comprising at least a pair of electrodes and a translucent tube coated on its inner surface with a plurality of types of phosphors that emit light in substantially the entire visible region when excited by ultraviolet rays. phosphor emits light, YP _{0. 85
V 0. 15 O 4, Y} 0. 9 Gd 0. 1 P 0. 85 V 0. 15 O 4, BaMg 2
Al ₁₆ O ₂₇ : Eu, BaMgAl ₁₄ O ₂₃ : Eu, Y ₂ Si
O _5: at least one selected from Ce, phosphor emitting red _{region, YP 0 65 V 0 35 O} 4:.. Eu, Y
A variable light color fluorescent lamp, which is at least one selected from ₂ O ₃ : Eu and Gd ₂ O ₃ : Eu. 3. A constant voltage is applied between the electrodes in advance,
After that, a pulse according to claim 1 is applied, and a method of lighting a fluorescent lamp. 4. A variable light color fluorescent lamp according to claim 2, wherein another rare gas and mercury are sealed in addition to the xenon gas. 5. A method of lighting a fluorescent lamp according to claim 1, wherein a variable light color operation is performed by accessing a card in which pulse conditions such as pulse voltage, pulse width, and repetition period are recorded.