JP2005339968A - Electrodeless fluorescent lamp and lighting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless fluorescent lamp capable of obtaining high average color rendering index even in the case of one with a high tube wall load. <P>SOLUTION: Discharge gas is sealed in a translucent glass bulb of the electrodeless fluorescent lamp and a phosphor layer is formed on the inner wall thereof. The phosphor layer contains a first phosphor having a peak at 610 nm on its spectrum, a second phosphor having a peak at 545 nm on its spectrum, and a third phosphor made of a composition of BaMg<SB>2</SB>Al<SB>16</SB>O<SB>27</SB>: Eu, Mn. The third phosphor is mixed in the phosphor layer by a weight percentage of 8% or more to 14.5% or less. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrodeless fluorescent lamp and an illumination device using the same.

  Unlike the conventional fluorescent lamp, the electrodeless fluorescent lamp, which was put to practical use in 1990, does not have an electrode that is a consumable member inside the lamp, and thus has a long life. Therefore, so far, it has been popularized mainly in the field of outdoor lighting as illumination for high-rise building outer walls and bridges where it is difficult to replace lamps. However, while further energy saving is screamed in recent years, it is spreading to the indoor lighting field as a general lighting application such as house lighting.

Fluorescent lamp phosphors include calcium halophosphate phosphors and rare earth three-wavelength phosphors. Unlike general fluorescent lamps, electrodeless fluorescent lamps are not limited to supplying power via electrodes, and can be supplied with relatively high-density power. Is often lit. In such applications, rare earth three-wavelength phosphors are used because calcium halophosphate phosphors are highly degraded. As a conventional example using a rare earth three-wavelength phosphor, for example, there is one shown in Patent Document 1 (Patent No. 02692470). This includes Y ₂ O ₃ : Eu (abbreviation YOX) as a red phosphor, LaPO ₄ : Ce, Tb (abbreviation LAP) or (CeTb) MgAl ₁₁ O ₁₉ (abbreviation CAT) as a green phosphor, and blue fluorescence A body using BaMg ₂ Al ₁₆ O ₂₇ : Eu (abbreviation BAM) or (SrCaBa) ₅ (PO ₄ ) ₃ Cl: Eu (abbreviation SCA) is shown.
Patent No. 02692470

  By the way, in a general fluorescent lamp, when a rare earth three-wavelength phosphor is used, an average color rendering index (Ra), which is an index of color rendering properties, can be as high as 80 or more. However, the reason is not clear at present, but the tube wall load (the lamp input power divided by the light emitting area of the lamp (the area of the portion where the phosphor coating is formed), ie, the lamp power per unit light emitting area) In a high electrodeless fluorescent lamp, when the phosphor shown in the above-described conventional example is used, the average color rendering index (Ra) may be only a low value of about 72 to 73, for example. That is, there is room for improving the average color rendering index as the lamp has a higher tube wall load. In particular, color rendering is not so important in outdoor lighting applications, but this high color rendering is more important in indoor lighting applications such as residential lighting.

  The present invention has been made in view of such problems, and the object of the present invention is to provide an electrodeless fluorescent lamp capable of obtaining a high average color rendering index even in an electrodeless fluorescent lamp with a high tube wall load. An object of the present invention is to provide a lamp and an illumination device using the lamp.

According to the first aspect of the present invention, in the electrodeless fluorescent lamp in which the discharge gas is sealed in the light-transmitting bulb and the phosphor layer is formed on the inner wall surface, the phosphor layer has an emission peak of approximately 610 nm. A first phosphor, a second phosphor having an emission peak of approximately 545 nm, and a third phosphor composed of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn. The mixing percentage weight of the phosphor 3 is 8% or more and 14.5% or less.

  The invention according to claim 2 is characterized in that the electrodeless fluorescent lamp according to claim 1 is provided in a lighting device.

According to the present invention, the phosphor layer provided on the inner wall of the bulb includes a first phosphor having an emission peak of about 610 nm, a second phosphor having an emission peak of about 545 nm, and BaMg ₂ Al ₁₆ O _27. : A third phosphor having a composition of Eu and Mn, and the mixing percentage by weight of the third phosphor in the phosphor layer is 8% to 14.5%, so that it is approximately 515 nm. Thus, the average color rendering index (Ra) can be improved.

This embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the electrodeless fluorescent lamp and coupler of this embodiment. FIG. 2 shows emission spectra of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (abbreviation BAM: Mn) and BaMg ₂ Al ₁₆ O ₂₇ : Eu (BAM). FIG. 3 is a diagram showing an emission spectrum of the electrodeless fluorescent lamp. FIG. 4 is a graph showing changes in the average color rendering index (Ra) with respect to the weight percentage of the mixed weight of the BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) phosphor.

  The electrodeless fluorescent lamp 100 of the present embodiment is formed of a bulb 1 in which a discharge gas is enclosed and a phosphor layer 6 is formed on the inner wall as shown in FIG. The bulb 1 is mounted on a coupler 5 including an induction coil 3 that is wound around the core 2 and generates a high-frequency electromagnetic field in the bulb 1 and a heat conductor 4 that dissipates heat generated by the core 2 to constitute a lighting device. doing.

  Specifically, the bulb 1 is obtained by processing a light-transmitting material such as a glass material into a substantially light bulb shape, and a rare gas such as argon or krypton and mercury are enclosed therein. On the inner wall surface of the bulb 1 are formed a phosphor layer 6 that converts ultraviolet rays emitted from mercury into visible light and a protective film (not shown) that protects the phosphor layer 6. A recess 7 that is recessed toward the inside of the valve 1 is formed at the root of the valve 1, and an exhaust pipe 8 that extends from the bottom of the recess 7 toward the root of the valve is provided. A base 9 for fixing the valve 1 to the coupler 5 is attached to the lower part of the valve 1.

Here, the phosphor layer 6 includes a red phosphor Y ₂ O ₃ : Eu (YOX) having an emission peak of about 610 nm as the first phosphor and a green having an emission peak of about 545 nm as the second phosphor. The phosphor is composed of LaPO ₄ : Ce, Tb (LAP) and a third phosphor, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn), which is a blue phosphor. That is, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) is used in place of the conventionally used blue phosphor BaMg ₂ Al ₁₆ O ₂₇ : Eu (BAM). FIG. 2 shows emission spectra of phosphors of BaMg ₂ Al ₁₆ O ₂₇ : Eu (BAM) and BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn), and the horizontal axis represents the emission wavelength of the phosphor. The vertical axis represents the emission intensity (relative value). From FIG. 2, in BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn), in addition to the emission peak of about 450 nm observed in BaMg ₂ Al ₁₆ O ₂₇ : Eu (BAM), the emission of about 515 nm. It can be seen that it also has a peak. The phosphor layer 6 is prepared by preparing a suspension in which the phosphor is dispersed in a butyl acetate solution in which nitrocellulose is dissolved together with a binder. Form.

  The electrodeless fluorescent lamp 100 shown above is attached to the coupler 5 as shown in FIG. The coupler 5 electrically couples the electrodeless fluorescent lamp 100 and a lighting circuit (not shown). The coupler 5 includes an induction coil 3 and a core 2 that are wound around the core 2 to generate a high-frequency electromagnetic field in the bulb 1. A heat conductor 4 that holds the generated heat while dissipating it is provided. The heat conductor 4 is formed in a substantially cylindrical shape using a metal having good heat conductivity such as aluminum, and one end of the heat conductor 4 extends in the radial direction in order to improve stability. The heat conductor 4 is inserted into the recessed portion 7 of the valve 1, and an exhaust pipe 8 is inserted through the heat conductor 4. A core 2 through which the magnetic flux generated by the induction coil 3 passes is attached to the side surface of the heat conductor 4. The core 2 is obtained by processing an Mn—Zn ferrite material having a high frequency magnetic property into a substantially cylindrical shape. On the outer surface of the core 2, an induction coil 3 is wound through an insulating layer to generate a high-frequency electromagnetic field in the bulb when a high-frequency current is applied from a lighting circuit (not shown).

  In the above configuration, when a magnetic flux is generated from the core 2 by flowing a high-frequency current having a frequency of 100 kHz to MHz on the induction coil 3, a high-frequency electromagnetic field is generated and the electrodeless discharge lamp 100 is turned on. Here, since the magnetic flux density is high in the vicinity of the induction coil 3, the tube wall load is particularly high.

When the electrodeless fluorescent lamp 100 is turned on, the emission spectrum shown in FIG. 3 is obtained. The horizontal axis of FIG. 3 indicates the emission wavelength of the electrodeless fluorescent lamp 100, and the vertical axis indicates the relative emission intensity. As shown in FIG. 3, the emission wavelength 515nm _{vicinity, BaMg 2 Al 16 O 27:} Eu BaMg 2 Al 16 O compared with the emission spectrum of _{(BAM) 27: Eu, Mn} (BAM: Mn) of the emission spectrum of It can be seen that the strength has increased. FIG. 4 shows an example of change in the average color rendering index with respect to the mixing weight percentage of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn). Here, the phosphor layer contains Y ₂ O ₃ : Eu (YOX) and LaPO ₄ : Ce, Tb (LAP) in addition to BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn). Here, the ratio of Y ₂ O ₃ : Eu (YOX) is 54.5%. And when changing the ratio of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn), the ratio of Y ₂ O ₃ : Eu (YOX) is fixed at 54.5%, and LaPO ₄ : Ce, Change the Tb (LAP) ratio. The ratio of each phosphor is Y ₂ O ₃ : Eu (YOX): LaPO ₄ : Ce, Tb (LAP): BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) = 54.5: 41.0 : In the case of 4.5, the average color rendering index is as low as 72.4, but without changing the mixing weight percentage of YOX (54.5%), the ratio of LAP was decreased and BaMg ₂ Al ₁₆ O ₂₇ When the mixing weight percentage of: Eu, Mn (BAM: Mn) is increased, the average color rendering index (Ra) is almost linear with the increase of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn). It turns out that it improves. When the mixed weight of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) is less than 8%, the average color rendering evaluation using the conventional BaMg ₂ Al ₁₆ O ₂₇ : Eu (BAM) However, if the mixture weight percentage of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) is further increased, the average color rendering index is improved and the value is about 14. If it exceeds 5%, the average color rendering index (Ra) is saturated. However, the average color rendering index (Ra) can be obtained even if all or part of the increase in BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) is reduced from Y ₂ O ₃ : Eu (YOX). The improvement is not seen.

As described above, the phosphor layer 6 is made of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn (BAM: Mn) having a mixed percentage by weight of 8% to 14.5% as a blue phosphor. The light emission in the vicinity of approximately 515 nm (blue-green) increases, which can increase the average color rendering index.

It is sectional drawing of the electrodeless fluorescent lamp and coupler of this embodiment. _{BaMg 2 Al 16 O 27: Eu} , Mn (BAM: Mn) and BaMg ₂ Al ₁₆ O _27: is a graph showing an emission spectrum of Eu (BAM). It is a figure which shows the emission spectrum of an electrodeless fluorescent lamp. _{BaMg 2 Al 16 O 27: Eu} , is a graph showing changes in the general color rendering index for mixing weight percentile weight ratio of Mn (Ra).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve | bulb 2 Core 3 Induction coil 4 Thermal conductor 5 Coupler 6 Phosphor layer 7 Recessed part 8 Exhaust pipe 9 Base 100 Electrodeless fluorescent lamp

Claims (2)

In an electrodeless fluorescent lamp in which a discharge gas is enclosed in a light-transmitting bulb and a phosphor layer is formed on an inner wall surface, the phosphor layer includes a first phosphor having an emission peak of approximately 610 nm, A second phosphor having an emission peak of 545 nm and a third phosphor having a composition of BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn, and a mixture percentage of the third phosphor in the phosphor layer An electrodeless fluorescent lamp characterized by having a weight of 8% to 14.5%.   An illumination device comprising the electrodeless fluorescent lamp according to claim 1.

Images