JPH0582016B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a fluorescent lamp, and more particularly to an L-EDL type high color rendering fluorescent lamp that satisfies the color rendering properties specified in JIS Z9112 and has improved luminous efficiency. BACKGROUND ART Conventionally, as an example of this type of fluorescent lamp, one having a structure in which two layers of fluorescent material are coated on the inner surface of a glass tube is known. The first layer of phosphor coated on the inner surface of the glass tube mainly uses titanium oxide, yellow pigment, zinc oxide, germanium salt, and arsenate phosphors.
Absorbs blue light below 470 nm and ultraviolet light between 300 and 400 nm. In addition, the second phosphor deposited on the discharge side includes magnesium tungstate that emits blue light, antimony-manganese activated calcium halophosphate that emits orange color, and tin-activated strontium magnesium orthophosphate that emits red light. Manganese-activated magnesium fluorogermanate, manganese-activated magnesium arsenate, which emit light, manganese-activated zinc silicate, and antimony/manganese-activated calcium halophosphate, which emit green light, are used. Problems to be Solved by the Invention In such a conventional configuration, the phosphors such as titanium oxide, yellow pigment, zinc oxide, germanium salt, arsenate, etc. used in the first layer absorb blue light of 470 nm or less. It has characteristics. Utilizing this feature, the first layer phosphor adjusts the blue light emitted from the second layer phosphor, which is necessary for improving color rendering, to provide high color rendering. However, these first layer materials
It also absorbs several percent of light emitted in a wavelength range larger than 470 nm, which causes a decrease in luminous efficiency. Therefore, if the coating amount of the first layer phosphor is reduced to reduce the absorption of blue light of 470 nm or less, the luminous efficiency will be improved, but the color rendering will be reduced. As described above, since the high color rendering type fluorescent lamp has contradictory characteristics of luminous efficiency and color rendering, there has been a problem in that it is difficult to improve both of them at the same time. The present invention has been made to solve these problems and provides a fluorescent lamp with improved luminous efficiency and color rendering properties. Means for Solving the Problem In order to solve this problem, the present invention has two phosphor layers deposited on the inner surface of the glass tube, the first layer being the phosphor layer deposited on the glass tube side. The light body is manganese-activated magnesium fluorogermanate (general formula: 3.5MgO・GeO ₃・
0.5MgF ₂ : Indicated by n・Mn ⁴⁺ , where n is 0.06≦
n≦0.12), and the coating amount of the first layer phosphor is
1.0 to 4.2 mg/cm ² , and the second layer of phosphor deposited on the discharge side is characterized by a fluorescent lamp that emits light in the wavelength range of 400 to 700 nm. . Effect The absorption effect of the manganese-activated magnesium fluorogermanate phosphor used in the first layer increases as the concentration of manganese, which is an activator, increases. By regulating the coating amount of the phosphor, the luminous efficiency can be improved and the color rendering index can be improved. Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. Two phosphor layers are applied to the inner surface of the glass tube. That is, the general formula for the first layer phosphor on the inner surface of the glass tube is 3.5MgO・GeO ₃・0.5MgF ₂ :n・Mn ⁴⁺ , where the value of n in the formula is 0.05, 0.06, 0.09, 0.12, and 0.13. Curve 1~ in Figure 1 with different manganese concentrations
Manganese-activated magnesium fluorogermanate phosphors having the spectral reflectances shown in Table 5 were applied in different amounts in the range of 0.8 to 4.3 mg/cm ² . On top of that, as a second layer phosphor, divalent europium-activated strontium aluminate (curve 6 in Figure 2) and tin-activated strontium magnesium orthophosphate (Fig. 2)
curve 7), manganese-activated magnesium fluorogermanate (curve 8 in Figure 2) and antimony-manganese activated calcium halophosphate (curves 9 and 1 in Figure 2).
A 40 watt diameter fluorescent lamp with a tube diameter of 32 mm was prepared using the usual method using 3.2 mg/ ^cm2 of a phosphor made of a mixture of 0) and measured. Shown in the table below.

【table】

[Table] The conventional example in the above table has the following configuration. That is, it has a structure in which two phosphor layers are adhered to the inner surface of the glass tube, and the first layer of phosphor on the glass tube side is made of titanium oxide and manganese-activated magnesium fluorogermanate in a weight ratio of 1:9. The mixture was mixed at a ratio of 1.2mg/ ^cm2 ,
On the second layer phosphor on top of that, 3.4 mg/cm ² of the same material as the second layer phosphor used in the example was deposited, and a 40 watt tube with a tube diameter of 32 mm was coated in the usual manner. This is a straight tube type fluorescent lamp. As can be seen from the table above, samples No. 5 to 6, No. 9 to No. 11, and No. 13 satisfy the color rendering index of the color rendering AAA type L-EDL fluorescent lamp specified in JIS Z9112.
~15. Furthermore, results were obtained in which the luminous flux of these devices was improved compared to the initial luminous flux of the conventional example. The first layer of phosphor on the glass tube side of the fluorescent lamp with such good results is made of manganese-activated magnesium fluorogermanate that absorbs at wavelengths below 470 nm, and the manganese concentration n at this time is The coating amount is within the range of 0.06≦n≦0.12.
It is in the range of 1.0 to 4.2mg/ ^cm2 , and the second
The layered phosphor consists of a phosphor that emits light in the wavelength range of 400 nm to 7 nm. Effects of the Invention As explained above, according to the present invention, two phosphor layers are deposited on the inner surface of the glass tube, and the first layer of phosphor deposited on the glass tube side has a wavelength of 470 nm or less. Manganese-activated magnesium fluorogermanate (general formula: 3.5MgO・GeO ₃・
0.5MgF ₂ : Indicated by n・Mn ⁴⁺ , where n is 0.06≦
n≦0.12), and the coating amount of the first layer phosphor is
The second layer of phosphor deposited on the discharge side is in the range of 1.0 to 4.2 mg/ ^cm2 , and the color rendering property specified in JIS Z9112 is achieved by comprising a phosphor that emits light in the wavelength range of 400 to 700 nm. It is possible to provide an L-EDL type high color rendering fluorescent lamp that satisfies the above requirements and has improved luminous efficiency.

[Brief explanation of drawings]

Figure 1 shows the spectral reflectance of manganese-activated magnesium fluorogermanate used as the first layer phosphor of a fluorescent lamp, depending on the manganese concentration. It is a spectral distribution map of the body.

Claims (1)

[Claims] 1 Two phosphor layers are deposited on the inner surface of the glass tube, and the first layer of phosphor is deposited on the glass tube side.
Manganese-activated fluorogermanic-activated magnesium fluorogermanate with absorption at wavelengths below 470 nm (general formula: 3.5MgO・GeO ₃・0.5MgF ₂ :n・Mn ⁴⁺
where n is 0.06≦n≦0.12), the coating amount of the first layer phosphor is in the range of 1.0 to 4.2 mg/cm ² , and the second layer is deposited on the discharge side. 400 phosphors
A fluorescent lamp characterized by being a fluorescent substance that emits light at a wavelength of ~700 nm.