JPH079793B2 - Fluorescent high pressure mercury lamp - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent high pressure mercury lamp with improved color rendering properties, and more particularly to a fluorescent substance deposited on the inner surface of an outer tube of a high pressure mercury lamp.

2. Description of the Related Art A fluorescent high pressure mercury lamp is one of the typical high pressure discharge lamps widely used for general lighting mainly for outdoor lighting due to its excellent life characteristics. The drawback of this lamp is its low color rendering property, and the average color rendering index Ra of CIE was about 43. In recent years, attempts have been made to improve the color rendering of fluorescent high pressure mercury lamps.
Ra was improved to about 55 by adding a blue-green phosphor in addition to the conventional red phosphor.

However, even this fluorescent high-pressure mercury lamp having improved color rendering properties is still insufficient for use for indoor lighting, and has not been widely spread. It is known that one of the reasons why the color rendering property is not sufficiently improved in the conventional method is that the 405 nm and 436 nm mercury emission lines emitted from the arc tube of the high pressure mercury lamp are too strong. . Regarding this mercury emission line output, for example,
The 405 nm output can be suppressed by using a titanium oxide film, but simply suppressing the mercury emission line in this way is considered unsuitable because it causes a decrease in lamp efficiency. It was That is, in the conventional color rendering improved high-pressure mercury lamp, since the color rendering property is improved without suppressing the mercury emission line in the short wavelength blue region, the improvement is not sufficient, and in order to be widely used for indoor lighting. However, further improvement was desired.

Problems to be Solved by the Invention Based on such circumstances, a phosphor having absorption in the short wavelength blue region has been recently developed, and a decrease in lamp efficiency caused by suppressing the mercury emission line in the short wavelength blue region is reduced. Consideration is being given to prevent it. For example, Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (hereinafter generally abbreviated as YAG: Ce ³⁺ ) is used as a phosphor having absorption in the short wavelength blue region, and is applied to a high-pressure mercury lamp together with a red phosphor. An example of attempting to improve the color rendering is disclosed in US Pat. No. 4034257, but the Ra of the lamp is about 51, which is not satisfactory.

The present invention relates to a high-pressure mercury lamp that suppresses mercury emission lines in the short wavelength blue region, and particularly to provide a fluorescent high-pressure mercury lamp whose color rendering property is significantly improved.

Means for Solving the Problems The fluorescent high-pressure mercury lamp of the present invention includes an arc tube that emits visible radiation and ultraviolet radiation, an outer tube that surrounds the arc tube, and a phosphor adhered to the inner surface of the outer tube. A coating film, the phosphor coating film is formed on the glass side of the inner surface of the outer tube, and emits 440n.
A first layer comprising a phosphor having an emission peak in the wavelength region of m to 540 nm and a phosphor having an emission peak in the wavelength region of 600 nm to 660 nm at the time of emission, and formed on the inner surface of the outer tube on the arc tube side. And a second layer containing a cerium-activated yttrium aluminate phosphor (YAG: Ce ³⁺ ).

The mercury emission line in the short wavelength blue region emitted from the arc tube is converted to YAG: Ce
^{When 3+} is absorbed, it is possible to greatly improve the color rendering property without lowering the lamp efficiency by suppressing the absorption of the light emission of other phosphors used at the same time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Examples Example 1 Y _0.95 VO ₄ : Eu ³⁺ _0.05 phosphor (emission peak wavelength: 619 nm)
Ba _0.8 Mg _1.93 Al ₁₄ O ₂₄ : Eu ²⁺ _0.2 , Mn ²⁺ _0.07 Phosphor (emission peak wavelength: 515 nm) was used, and their weight mixing ratio was 75:25.
Were weighed so as to put the mixture 250g 1% nitrocellulose solution in butyl acetate 250 cc, was coated in a thickness of 2.0 mg / cm ² density adjustment were mixed well carried out inner surface of 100w high-pressure mercury lamp No. Layer 1 was constructed. Then YAG: Ce ³⁺ 25
Weigh g, 250cc of 2% ethyl cellulose butyl acetate solution 250cc
0.1 mg / cm on the first layer after well dispersed and mixed.
^{The second} layer was formed by coating with a film thickness of 2. After that, a 100w fluorescent high-pressure mercury lamp was manufactured by using a normal lamp manufacturing process. The luminous flux of the obtained lamp is 4750 lm, color temperature is 4100K, Ra is 6
1 and the Ra of the conventional fluorescent high-pressure mercury lamp is about 50 to 55, the color rendering is clearly improved, and the yellow color which is the base color of YAG: Ce ³⁺ is not conspicuous, and the lamp appearance It was also white and preferable. FIG. 1 shows the spectral reflection spectrum of the YAG: Ce ³⁺ phosphor used in this example. The spectral distribution of the 100w fluorescent high pressure mercury lamp according to this example is shown in FIG.

Example 2 A phosphor layer having the same structure as in Example 1 was applied to the inner surface of a 400w outer tube to prepare a 400w fluorescent high pressure mercury lamp. The luminous flux of the obtained lamp was 25300 lm, the color temperature was 3830K, and the Ra was 58. The lamp had a clearly improved color rendering property and the lamp had a white appearance, which was preferable.

Example 3 Y _0.95 V _0.5 P _0.5 O ₄ : Eu ³⁺ _0.05 phosphor (emission peak wavelength:
619 nm), Ba _0.8 Mg _1.6 Al ₁₄ O ₂₄ : Eu _0.2 , Mn _0.4 phosphor (emission peak wavelength: 517 nm) and Ba _0.9 Mg ₂ Al ₁₄ O ₂₄ : Eu _0.1 phosphor (emission peak wavelength: 450 nm). , Weigh them so that the weight mixing ratio becomes 85: 10: 5, disperse and mix with 1% nitrocellulose butyl acetate solution, and then film thickness of 3.0mg / cm ^{2 on} the inner surface of the outer tube of 100w high pressure mercury lamp. To form the first layer. Then, 25 g of alumina powder and 25 g of YAG: Ce ³⁺ were weighed, dispersed and mixed using a 2% ethyl cellulose butyl acetate solution, and then coated on the first layer at a film thickness of 0.2 mg / cm ² , The second layer was constructed. After that, a 100w fluorescent high-pressure mercury lamp was manufactured by using a normal lamp manufacturing process. The luminous flux of the obtained lamp is 4700 lm, color temperature 3850K, Ra is 60,
The lamp had a clearly improved color rendering and the white appearance of the lamp was preferable.

Example 4 Y _0.95 VO ₄ : Eu ³⁺ _0.05 phosphor and 3.5MgO · 0.5MgF ₂ · CeO ₄ : Mn
⁴⁺ phosphor (emission peak wavelength: 659 nm) and Sr ₂ Si ₃ O ₈・ 2SrC
After using l ₂ : Eu ²⁺ phosphor (emission peak wavelength: 490 nm) so that their weight mixing ratio would be 60: 5: 35, and dispersing and mixing with 1% nitrocellulose butyl acetate solution , A 100w high pressure mercury lamp was coated on the inner surface of the outer tube with a film thickness of 2.0 mg / cm ² to form a first layer. Then Y _0.95 VO ₄ : Eu ³⁺
_0.05 phosphor and YAG: Ce ³⁺ phosphor were weighed so that the weight mixing ratio was 96: 4, dispersed and mixed using a 2% ethyl cellulose butyl acetate solution, and then 1.0 on the first layer. mg /
The second layer was formed by coating with a film thickness of cm ² . After that, a 100w fluorescent high-pressure mercury lamp was manufactured by using a normal lamp manufacturing process. The luminous flux of the obtained lamp is 4580lm, color temperature 3700K, Ra
Was 63, which clearly had improved color rendering and the appearance of the lamp was also favorable.

EFFECTS OF THE INVENTION As described above, the present invention can provide a fluorescent high-pressure mercury lamp that can significantly improve color rendering properties and can suppress a decrease in lamp efficiency as much as possible without impairing the favorable appearance of the lamp. It is a thing.

[Brief description of drawings]

FIG. 1 is a diagram showing the spectral reflection spectrum of YAG: Ce ³⁺ shown in Example 1 of the present invention, and FIG. 2 is a diagram showing the spectral distribution of the fluorescent high-pressure mercury lamp shown in Example 1 of the present invention. .

Claims (1)

[Claims] 1. An arc tube that emits visible radiation and ultraviolet radiation, an outer tube that surrounds the arc tube, and a phosphor coating film formed on the inner surface of the outer tube. A first layer formed on the glass side of the inner surface of the outer tube, comprising a phosphor having an emission peak in the wavelength region of 440 nm to 540 nm when emitting light and a phosphor having an emission peak in the wavelength region of 600 nm to 660 nm when emitting light; Formed on the arc tube side of the inner surface of the outer tube 3
And a second layer containing a cerium-activated yttrium aluminate phosphor.