JPS60185354A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To improve the lamp efficiency and the color rendering by forming the phosphor substance layer with first to fourth phosphor substances including such one as has the light emission peak wavelength of 470-500nm and emits light in an narrow band where the half level width of light emission is 40-75nm. CONSTITUTION:First phosphor substance having the peak wavelength of 470- 500nm while emits light in a narrow band where the half level value of light emission is 40-75nm, second phosphor substance such as tin-activated positive strontium.magnesium phosphor substance and third phosphor substance such as antimony.manganese-activated alkali-earth metal halo-phosphate, antimony- activated alkali-earth metal halo-phosphate are mixed and adhered to the inner wall of a glass tube to produce a fluorescent lamp. Consequently, highly efficient and stable phosphor substance such as halo-phosphoate can be added resulting in considerable improvement of the lamp efficiency and the color rendering through the service life.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fluorescent lamp, specifically a fluorescent lamp with a color temperature of 4200.
has a value of ~5600 and has a color rendering index of J
The present invention relates to a high color rendering type fluorescent lamp whose color rendering classification is EDL type and whose light source color classification satisfies the numerical values of white as defined in ISZ9301.

Conventional structure and problems The phosphor conventionally used in fluorescent lamps for general lighting is antimony/mankan activated calcium halophosphate phosphor, but this lamp has a low color rendering property, so it is not suitable for museums or museums. There are restrictions on its use in places where high color rendering properties are required, such as color printing factories. Fluorescent lamps with high color rendering properties, for example, are made by mixing several types of phosphors to approximate the spectral distribution of a reference light source, while using mercury emission lines in the short wavelength region of the visible region, which inhibits the improvement of color rendering properties. KDL-type fluorescent lamps using so-called two-layer coating, which also uses a method to suppress
No. 895) is known as h2.

3., -1.

However, with these conventional methods, the lamp manufacturing process is complicated, production efficiency is reduced, and variations in color rendering properties and reduction in lamp efficiency are unavoidable, which has been a long-standing problem.

In recent years, fluorescent lamps that have improved the above problems (Japanese Patent Laid-Open No. 1986-
102073, Japanese Patent Application Laid-Open No. 1983-40763)
was proposed and made some progress.

However, the former (Japanese Unexamined Patent Publication No. 54-102-73) mainly consists of a divalent europium-activated strontium phosphate phosphor and a tin-activated strontium/magnesium phosphate phosphor, and has an average color rendering index Ra of 99. In order to increase the chromaticity of the lamp and set the chromaticity of the lamp on the blackbody locus, a small amount of calcium halophosphate phosphor and zinc silicate phosphor are further added to provide a fluorescent lamp. Zinc silicate phosphors are relatively susceptible to deterioration when applied to fluorescent lamps, and therefore have the disadvantage that the special color rendering index decreases during the life of the lamp due to a decrease in the green component. On the other hand, the latter (Japanese Unexamined Patent Publication No. 58-40763) is a combination of an alkaline earth metal phosphate phosphor activated with divalent europium and a tin 4 active strontium magnesium orthophosphate phosphor. High efficiency with a mixture of two types of phosphors.

Although it provides a fluorescent lamp that achieves high color rendering,
In this case, the phosphor is a mixture of two types, so it is simple, but the emission spectrum changes easily with a slight change in the phosphor composition.Alkaline earth metal halophosphate fluorescence activated with divalent europium Since the luminescence color of this phosphor changes slightly, the chromaticity of the lamp changes by, for example, 50
The drawback is that it is impossible to maintain the color temperature on the black body locus at a color temperature of 0.00, and that the emission spectra of the two types of phosphors must be strictly defined when color matching is performed in the lamp manufacturing process.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks and provides an EDL-type fluorescent lamp, which improves lamp efficiency, facilitates color matching in the lamp manufacturing process, and is stable throughout its life. This provides a fluorescent lamp with high color rendering properties.

Structure of the Invention The fluorescent lamp of the present invention has a peak emission wavelength of 470 nm.
m~600nm, and the half width of the emission is 40nm~75
A first phosphor that emits light in a narrow band of nm and a second phosphor that is at least one kind of a tin-activated strontium-magnesium phosphate phosphor and a tin-activated strontium-barium-magnesium phosphate phosphor. and a third phosphor that is at least one of an antimony-manganese-activated alkaline earth metal halophosphate phosphor and an antimony-activated alkaline earth metal halophosphate phosphor,
This fluorescent lamp is characterized by being coated on the inner wall of a glass tube, which improves lamp efficiency, facilitates color matching during the lamp manufacturing process, and exhibits stable high color rendering throughout the lamp life. This is something that can be used to provide lamps.

Description of Examples In order to achieve high color rendering properties with an average color rendering index Ra of 96 or higher in fluorescent lamps, it is insufficient to adjust the spectral distribution by mixing phosphors, and the visible region must be shortened. It is well known that it is necessary to suppress the emission energy of 405 nm and 436 nm, which are mercury emission lines in the wavelength region. In recent years, efforts have been made to improve the efficiency of fluorescent lamps with high color rendering properties.
The materials used to suppress the mercury bright line in the short wavelength region of the visible region are strontium borate phosphor activated with divalent europium, and barium calcium-magnesium halophosphate phosphor activated with divalent europium. Also, an EDL type fluorescent lamp has been proposed in which the lamp efficiency is improved by using a blue-green phosphor such as a strontium-magnesium aluminate phosphor activated with divalent europium.

These blue-green phosphors activated with divalent europium have a wide half-value width of 80 nm to 120 nm, so they can be mixed with existing orange phosphors (for example, strontium magnesium phosphate). In the conventional technology of η- et al., the lamp efficiency is equal to the luminous output of the blue-green phosphor and the orange phosphor. The addition of a phosphor that is bright enough to improve the lamp efficiency has been shown to have no effect on the color rendering properties of the lamp.

Based on these circumstances, the present inventors used a phosphor that emits blue-green light with a narrow half-width, contrary to the conventional method, as a material for suppressing the mercury bright line, and mainly aimed at improving lamp efficiency. Experiments were conducted on combinations with many phosphors for the purpose, and it was found that the peak wavelength of light emission was between 470 nm and 600 nm as a green-emitting phosphor, and the half-value rlJ of light emission was between 40 nm and 75 nm, emitting light in a narrow band. It has been discovered that a fluorescent lamp configured as described in the claims by selecting a phosphor shown in the patent claims has improved lamp efficiency compared to a conventional EDL type fluorescent lamp, and exhibits a stable high color rendering property throughout its life. It is something that

Furthermore, by using a blue-green phosphor that emits light in a narrow band as described above, it is possible to achieve high efficiency, which has traditionally been difficult to add to an extent that clearly improves lamp efficiency while maintaining high color rendering properties. This makes it possible to proactively use phosphate phosphors, which are stable and inexpensive.

Therefore, the half value rlr of the light emission of the blue-green phosphor that emits light in the narrow band is 40n, m-7Cin50nm to 70nm.
It was found to be even more effective in the case of Unfortunately, in the fluorescent lamp of the present invention, in addition to the first phosphor and the second phosphor, a third phosphor that can change the color of the emitted light is used. It is clear that the fluorescent lamp also has the advantage of being easy to perform so-called color matching, such as adjusting the chromaticity or color rendering properties of the fluorescent lamp.

Furthermore, the absorption of light in the short wavelength region of the visible region of the blue-green phosphor suitably used in the fluorescent lamp of the present invention was investigated, and the reflectance at the wavelength of 436 nm, which is the mercury emission line, was 20φ to 8o%. It is fine, preferably 2 to 40
I confirmed that it was Section 75. This can be achieved, for example, by using a series of phosphors with the symbol A1 shown in Table 1 (described later) whose spectral reflectance is changed by changing the concentration of divalent europium, which is a phragmatic agent. This has been confirmed through one experiment. FIG. 1 shows the measured data of the spectral reflectance. In Figure 1 VC, curve 1 is S r
3Jl s E uO,. 2A11402□1 Curve 2 is S r5.9,, E uo. . 8 A/(+4025
, curve 3 is Sr3.60EuOjOAA+40251 curve 4 is S”3,20 EuO.80 Aeu o25
This is the spectral reflectance curve of

As is clear from FIG. 1, by appropriately selecting these blue-green phosphors, it is possible to control absorption in the short wavelength region of the ri]' visual region and liquid region. This advantage is that for lamps with a high color temperature that use a relatively large amount of blue-green phosphor, a material with low absorption is selected, and for a lamp with a low color temperature, a material with high absorption is selected. The mercury bright line output from fluorescent lamps in the short wavelength region of the visible region can be controlled.

Table 1 shows the luminescent properties of typical phosphors preferably used in the present invention.

101,-2 Figure 2 shows the emission spectra of these phosphors upon excitation with ultraviolet light. The symbols in the figure correspond to those in Table 1. However, as for the halophosphate phosphors shown in 7.01 to C5 in Table 1, their emission spectra are well known and are therefore omitted here.

The present invention will be explained in detail below.

Mix each color phosphor 1~. A 40 watt straight tube fluorescent lamp was manufactured by applying the phosphor mixture to the inner wall of a glass tube having a tube diameter of 32 mm according to a conventional manufacturing method [7].

Table 2 shows the types of phosphors (indicated by the symbols in Table 1) and their mixing ratios, and also shows the lamp characteristics obtained along with known examples.

13 Heh.

As is clear from Table 2, it can be seen that the fluorescent lamp of the present invention has clearly improved color rendition which is comparable to that of the conventional lamp, and has a lamp efficiency of 1 to 1. The known example shown here is the conventional two-layer coating ED.
It is an L-shaped fluorescent lamp.

In the fluorescent lamps of Examples 1 to 4, a divalent europium strontium aluminate phosphor (symbol A+ in Table 1) is arranged as the first phosphor, and the EDL
It can be seen that the lamp exhibits a sufficiently high color rendering property and a significantly improved lamp efficiency as a fluorescent lamp. Among the fluorescent lamps of Examples 5 to T, the improvement in lamp efficiency is slightly smaller in A, which is a divalent europium calcium magnesium silicate fluorescent material that is slightly inferior in terms of luminous output as the first phosphor that emits light in a narrow band. This is because a strontium activated strontium or divalent europium-activated magnesium silicate phosphor is used, and if the brightness of these phosphors can be improved, an improvement in lamp efficiency can be expected. .

As a result of the life test, it was clear that the fluorescent lamp of the present invention has an improved luminous flux maintenance rate. For example, all the fluorescent lamps shown in the above embodiments have a luminous flux thread 1] of VC6=j and 9o to 95 for 100 hours after being lit for 3000 hours, whereas [7. )'1. The numbers ranged from 85 to 88. Figure 3 shows the distribution of the fluorescent lamp obtained in Example 2.

Effects of the Invention - As explained above, the fluorescent lamp of the present invention has an additive that suppresses the mercury bright line in the short wavelength region of the visible region, which inhibits the improvement of its color rendering properties, and reduces the peak wavelength of light emission. is 470n
m ~ 500nmK, half width of emission is 40nm ~ 5n
By using a phosphor that emits light in a narrow band, it has been difficult to add a phosphor that maintains a high color rendering property to an extent that clearly improves lamp efficiency. It is now possible to select and add highly efficient and stable phosphors such as phosphors, thereby improving lamp efficiency and providing an EDL type fluorescent lamp with stable high color rendering properties throughout its life. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the spectral reflectance of a blue-green phosphor suitably used in the fluorescent lamp of the present invention, and Fig. 2 is a diagram showing the emission spectrum of the phosphor used in the fluorescent lamp of the present invention upon ultraviolet excitation. , FIG. 3 is a diagram showing the spectral distribution of the fluorescent lamp shown in Example 2 of the present invention1,

Claims (1)

[Scope of Claims] A fluorescent lamp comprising an ultraviolet generating mechanism in a glass tube and a phosphor formed on the inner wall of the glass tube that emits light in the visible light range when excited by the ultraviolet rays, wherein the phosphor emits light in the visible light range. The peak wavelength of is in the range of 470 nm to 500 nm, and the half value of the emission (width of the emission spectrum measured at the emission intensity at 60% of the maximum emission intensity) is 40 nm, m to 76 nm.
a first phosphor that emits light in a narrow band of nm; and a second phosphor that is at least one of a tin-activated strontium magnesium phosphate phosphor and a tin-activated strontium magnesium phosphate phosphor. and a third phosphor that is at least one of an antimony-activated manganese-activated alkaline earth metal halophosphate phosphor and an antimony-activated alkaline earth metal halophosphate phosphor. Fluorescent lamps with this characteristic. 2 base 7