JPS6363783A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To provide a fluorescent lamp of high output and high color rendering which exhibits little decrease of total luminous flux and color drift after lighting and which comprises a glass bulb and, provided on the inner surface thereof, a phosphor film composed of a mixture of particular 1st-3rd phosphors having emission spectra in the visible blue, visible green and visible red regions, respectively. CONSTITUTION:A phosphor film obtd. by blending together 0.2-35wt% first phosphor (A) of formula I (wherein 0.1<=w<=0.5, 0.0004<=x<=0.0020, 0.1<=y<=0.8, and 0.03<=z<=0.10, provided that w+x+y+z=1; 1.5<=a<=4.5; and 0.0005<=b<=0.0030) having emission spectra in the visible blue region, 35-60wt% second phosphor of formula II (wherein Ln is at least one member selected from among La, Gd, Y, Ce, and Tb; 1.5<=a<=5.0; and 2.5<=b<=14.0; 0.001<=x<=0.005; 0.0002<=y<=0.0010) having emission spectra in the visible green region and 30-60wt% third fluorescent material of formula III (wherein 0.020<=x<=0.065) having emission spectra in the visible red region is formed on the inner surface of a glass bulb, thereby obtaining a fluorescent lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to fluorescent lamps, in particular to high power, high color rendering fluorescent lamps.

(Prior Art) In recent years, fluorescent lamps for general lighting have been required to have high output and high color rendering, and one way to meet these demands is to use blue, green, and red light-emitting phosphors that have relatively narrow emission spectra. There is a three-wavelength fluorescent lamp that uses a mixture of two wavelengths in an appropriate ratio. In this type of fluorescent lamp, the emitted light colors of the phosphors used are significantly different, so that after the lamp is turned on, a color shift phenomenon occurs due to the difference in the deterioration rate of each phosphor, reducing the commercial value. Japanese Patent Application Laid-open No. 57-2076 as one of the conventionally known three-wavelength fluorescent lamps.
As stated in Publication No. 78, 3 (M
xEu)s (POa)2 ・M'CR2 or x (
Mt-pEupo) ・y P2O3・a M'X2
・b B20B, as a green-emitting phosphor (Rex-c-
d-3e Tbe Cea A3e)203゛qsio
2°r P2O5° as a red-emitting phosphor (YxEu)
There are 203 combinations, but in these cases, a color shift phenomenon occurs after the lamp is turned on due to the difference in the deterioration rate of each phosphor.
There is room for improvement in this respect. Furthermore, as the rate of deterioration of these phosphors increases, the total luminous flux as a lamp decreases significantly, and there is still room for improvement in this respect.

(Problems to be Solved by the Invention) As described above, fluorescent lamps, particularly high-output, high-color-rendering fluorescent lamps, are desired to have a small color shift after the lamp is turned on, and a small decrease in total luminous flux.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a fluorescent lamp in which the phenomenon of color shift after lighting is extremely small and the decrease in total luminous flux is small.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the inventors conducted combination experiments on various phosphors, and as a result, they found that the blue color according to Japanese Patent Application No. 1986-86183, which the inventors had already filed, The present invention has been completed based on the discovery that a mixed phosphor obtained by mixing a light-emitting phosphor, a green-emitting phosphor disclosed in Japanese Patent Application No. 120208/1982, and a known red-emitting phosphor in a certain ratio exhibits good characteristics.

That is, the present invention provides a fluorescent lamp equipped with a fluorescent film on the inner surface of a glass bulb, in which the fluorescent film has an emission spectrum in the visible blue region and has a general formula (Ba, CaxMgyEuz).
O・a 120B・b 5i02 (However, W is 0
．． 1≦w≦0.5. x is 0.0004≦x≦0.0
020. y is 0.1≦so≦0.8. z is 0.03
≦z≦0.10. w + engineering + y + Z = 1, a is 1.5≦
a≦4.5. b is 0.0005≦b≦0.0030)
A first phosphor represented by the general formula Ln20B ja (Mgx-x(
Caw)O・b [(A4203)x-y (SiOz
) vl (However, Ln is lantern La.

Gadolinium Gd, Yttrium Y, Cerium Ce.

At least one type of terbium Tb, a is 1.5≦
a≦5.0. b is 2.5≦b≦14.0. x is 0
．． 001≦x≦o, oos, y is 0.0002≦ν
≦0.0010) and a general formula (Yx-xEux) having an emission spectrum in the visible red region
It consists of a mixture with a third phosphor expressed as zoa (where 0.020≦x≦0.065). mixture 10
With respect to 0% polymerization, the first phosphor is 0.2 to 35% by weight, the second
It is preferable to mix 35 to 60% by weight of the phosphor and 30 to 60% by weight of the third phosphor, and is characterized by coating the inner surface of the glass bulb.

(Function) With the above-described configuration, the present invention has the effect that color shift is reduced and decrease in total luminous flux after lighting is reduced.

If the first phosphor and the second phosphor of the present invention deviate from the various limited numerical ranges, good characteristics cannot be obtained.The numerical range of the third phosphor is a well-known range. It is.

1st. If the blending ratio of the second and third phosphors deviates from this range, the color rendering properties will deteriorate, making it impractical.

Table 1 shows the luminous output (total luminous flux) immediately after fabrication and after lamp operation for 500 hours when a fluorescent lamp was fabricated by applying blue, green, and red emitting phosphors individually to the inner surface of a glass bulb. It is.

Compared to the phosphors used in conventional fluorescent lamps, the phosphor used in the fluorescent lamp of the present invention had a higher luminescence output maintenance rate for blue, green, and red emitting phosphors, and the retention rates for the three colors were similar. It shows the value.

This indicates that in the three-wavelength fluorescent lamp, the color shift phenomenon after lighting is small, and the decrease in total luminous flux is small.

In Table 2 below, the phosphors shown in Table 1 were removed from fluorescent lamps and their reflectances were measured. The phosphor used in the fluorescent lamp of the present invention has a higher reflectance than the phosphor used in conventional fluorescent lamps. This is thought to be because the phosphor deteriorated due to the reaction between the phosphor and mercury in the fluorescent lamp while the lamp was on, resulting in a lower reflectance. There is a similar tendency in the decrease in reflectance and the decrease in light emission output, and it is thought that the decrease in reflectance promotes the decrease in light emission output.

Table 2 (Example) (Example-1) As a blue-emitting phosphor (Bao, a cao, 0020
Mgo, 5Euo, s+so) 0 ・2.5AR2
0B ・15% by weight of 0.0030Si02 as a green-emitting phosphor (La□, 5 Ceo, 3τbo, 2) 2
0s ・2.0 (Mgo, sse Cao, oox)
O°8. O[(AQ203)o,ss9g(Si02)
. ,. . 04] as a red-emitting phosphor (
Yo, 960[:uo, 040)20!1 to 35
% by weight was mixed and applied to the inner surface of a glass bulb to produce a fluorescent lamp FL20SS/1 g. At this time, the emitted light color immediately after the lamp is manufactured (after 0 hours) is given by χ=
0.33Jy=0.357. This fluorescent lamp was lit for 500 hours, and the color of the emitted light was measured. Further, the light emission output (total luminous flux) at 0 hours was 102%, and the light emission output after 500 hours was 112%.

Therefore, compared to the comparative example, the color shift is small and the decrease in light emission output is also small.

(Example-2) As a blue-emitting phosphor (Bao, sse Cao, .

,.

Mgo, 5Euo, oa) OH2,5Aj1203 ・
0.0010Si02 at 10 %, as a green emitting phosphor (LaO16Ce6.3Tbo, 2) 203 ・
2.5 (Mgo, ssa Cao, ooz) O°5. O
[(AR20a)o, 5sea(Si02)o, 00
02] was added to 60% by weight of the red light-emitting phosphor (Yo,
s+6Euo, oas) 203 was mixed at 30% by weight and evaluated in the same manner as in Example-1. At this time, the emission color after 0 hours is x=0.340. ν=0.356 total luminous flux is 10
1%, luminescent color after 500 hours = 0.341. y=
0.358 total luminous flux was 110%. Therefore, compared to the comparative example, the color shift is smaller and the decrease in total luminous flux is also smaller.

Examples are shown in Table 3 in the same manner below.

Margins below [Effects of the Invention] As described above, the present invention can provide a fluorescent lamp with small color shift after lighting and a small decrease in total luminous flux.

Agent Patent Attorney Noriyuki Chika Same Norio Ogo Procedural amendment (marshal)

Claims (1)

[Claims] In a fluorescent lamp having a phosphor film on the inner surface of a glass bulb, the phosphor film has an emission spectrum in the visible blue region and has a general formula (Ba_wCa_xMg_yEu_z)O・a.
Al_2O_3・bSiO_2 (however, w is 0.1≦w
≦0.5, x is 0.0004≦x≦0.0020, y is 0.1≦y≦0.8, z is 0.03≦z≦0.10, w
+x+y+z=1, a is 1.5≦a≦4.5, b is 0.
0005≦b≦0.0030), and a general formula Ln_2O having an emission spectrum in the visible green region.
_3・a(Mg_1_−_x(Ca_x)O・b[(A
l_2O_3)_1_-_y(SiO_2)y] (Ln is at least one of lanthanum La, gadolinium Gd, yttrium Y, cerium Ce, and terbium Tb, a is 1.5≦a≦5.0, and b is 2.5 ≦b≦14
．． 0, x is 0.001≦x≦0.005, y is 0.00
02≦y≦0.0010);
General formula (Y_1_
−_xEu_x)_2O_3 (x is 0.020≦
x≦0.065), and the amount of the first phosphor is 0.0% with respect to 100% polymerization of this mixture.
2 to 35% by weight, 35 to 60% by weight of the second phosphor, and the third
A fluorescent lamp characterized by containing 30 to 60% by weight of phosphor.