JPS60148044A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To obtain a fluorescent lamp having special color rendering and high luminous efficiency by coating the inner surface of a glass tube with mixture prepared by combining five kinds of special phosphors activated with Eu or Tb. CONSTITUTION:A first phosphor consisting of an alkaline earth metal halophosphate activated with divalent Eu and represented by formula M5-xX(PO4)3:Eu<2+>(x) is prepared; in the formula, M represents mixture composed of 3.0-4.5 gram atoms of Ba, 0.5-2.0 gram atoms of Ca and 0.01-1.0 gram atoms of Mg. A second phosphor is selected which has an emission peak at 620-640nm and has a half width of 120-160nm. A third phosphor is selected which is activated with divalent Eu and has an emission peak at 440-455nm. A fourth phosphor is selected which is activated with trivalent Tb and emits yellowish green color. A fifth phosphor is selected which is represented by formula Ln2O3:Eu (Ln is Y, La or Gd.) After the above five kinds of phosphors are properly mixed, the mixture is applied to the inner surface of a glass tube thereby making a fluorescent lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a high color rendering fluorescent lamp. For more details,
This invention relates to a high color rendering fluorescent lamp that has both high color rendering properties and high luminous efficiency.

[Technical background of the invention and its problems] The so-called average color rendering index Ra is used as a measure of how faithfully a light source can reproduce an object color. Expressed on this scale, a general lighting fluorescent lamp using a calcium helophosphate phosphor activated with antimony and manganese is white (color temperature 4200"K) and has a Ra
-85, and Ra=75 for daylight color (color temperature 6500''K). By the way, the color rendering properties of fluorescent lamps can be further improved by improving the phosphor used.

High color rendering lamps vary depending on the degree of improvement in color rendering.
OL (75<Ra), 5OL(85<Ra
), EDL (E15 < Ra) type and JIS 29
Lamps using various combinations of phosphors are known.

For example, the fluorescent lamp disclosed in Japanese Patent Application Laid-Open No. 102073/1980 has Ra=I39 due to the combination of four types of phosphors. In addition, the 1981 Illuminating Society of Japan National Conference Proceedings No. 1
No. 8 describes that a fluorescent lamp with a high color rendering index comparable to the above-mentioned average color rendering index can be obtained by mixing two types of phosphors. All of these fluorescent lamps belong to the EtlL type of fluorescent lamp color rendering classification. However, the luminous flux of these lamps has a color temperature of 5000”K f)
40W 5 pump (pipe diameter 32mm) Te24001m
(efficiency H1m/11).

In addition, Japanese Patent Application Laid-open No. 18887/1987 describes a fluorescent lamp with relatively high color rendering properties and high efficiency, for example, 4
A lamp (so-called three-wavelength fluorescent lamp) comprising a combination of three types of narrow-band emitting phosphors having emission peaks around 50 nm, 545 nm, and 810 n+s is disclosed.

Due to the development of fasting light materials and improvements in phosphors, three-wavelength lamps have recently become 40W lamps with a color temperature of 5000@380.
A luminous flux of 0.01 rin (efficiency sO1/If) can be obtained.

Moreover, the average color rendering index is Ra=84, and DI'! i
It is divided into l. This lamp is highly practical as it has both a certain degree of high color rendering and high efficiency.

However, in this lamp, it was difficult to improve Ra to a higher value. Furthermore, since the light emission is concentrated in the regions centered around 45 nm, 545 nm, and 810 nm as described above, although Ra is relatively high, some of the special color rendering index values are quite low. This is a drawback that cannot be overcome with a three-wavelength lamp. Furthermore, the phosphors used in this type of lamp usually all contain rare earth elements, making the cost of the phosphors extremely high.

As described above, EDL type high color rendering fluorescent lamps have low efficiency, and OL type high color rendering fluorescent lamps have low Ra and special color rendering index, so EDL is a fluorescent lamp that solves the above problems. There are high expectations for the SDL type lamp, which is located between the OL type and the OL type. An example of a lamp belonging to this category is the one described in Toshiba Review, Vol. 28, p. 1110 (1871). this is,
40W lamp, Ra=112, total luminous flux 24001m (
It has an efficiency of 80 m1/It). However, the efficiency of this lamp was only comparable to that of the EDL type.

Therefore, as a practical high color rendering fluorescent lamp, Ra is 88.
Even if it is a slightly smaller value, the luminous efficiency is 24001 m
/40w or more, and the luminous efficiency is 38001m/40w or more.
Even if the value is slightly smaller than 40.111, Ra is 75.
A lamp that satisfies the above requirements and has excellent special color rendering properties has been desired.

[Object of the Invention] The present invention provides a lamp that has properties intermediate between a lamp with an Ra of about 88 but low efficiency and a lamp with an Ra of about 84 but high efficiency, and which has excellent special color rendering properties. The purpose is to provide

[Summary of the Invention] As a result of extensive research to achieve the above object, the present inventors have discovered that by combining five specific types of phosphors, R
A lamp that reaches almost 88 but has low efficiency and Ra of 8
The present invention has been completed based on the discovery that a lamp with properties intermediate to that of a high-efficiency lamp of about 4 can be made as desired.

That is, the fluorescent lamp of the present invention has the general formula 2M! ,KX
(PO4)3: ELL”(ri (where M is 3.
represents an elemental mixture consisting of 0 to 4.5 gram atoms of Ba, 0.5 to 2.0 gram atoms of Ca, and 0.01 to 1.0 gram atoms of Ng, where X is F, ll:l, Br represents a single substance or a mixture of two or more types, and X is 0.01<
a first phosphor consisting of an alkaline earth metal halophosphate activated with divalent europium, represented by x≦0.2 (representing a number in the range of x≦0.2); an emission peak in the intestinal wavelength range of 620 to 640 nm; and a second phosphor having a half-value width of 120 to 1801 layers; activated with divalent europium and having an emission peak of 4! from the 440n layer; a third phosphor that is within the +511 range and emits blue light; a fourth phosphor that is activated with trivalent terbium and emits yellow-green light; and a rare earth activated with trivalent europium. This relates to a fluorescent lamp in which a fifth phosphor made of an oxide and which emits red light is mixed and adhered to the inner surface of a glass tube.

In the present invention, the first phosphor is a component that provides energy in the blue-green light region in the spectral energy distribution of the lamp.

In the general formula of the first phosphor, the index X represents the concentration of divalent europium, and when X is 0.01 or less,
Since the brightness is extremely low and there is no noticeable improvement in brightness even if it exceeds 0 or 2, set the range of 0.01<x≦0.2.0M Ba, Ca, and Mg each have Ba=3.0 ~4.
5 grams atom, Ca=0.5-2.0 grams atom,
a set to satisfy the relationship of Ng = 0.01-1.0 gram atom; Ba = 3.0-4.5 gram atom;
The reason why Ca is set to 0.5 to 2.0 gram atoms is to provide an emission peak in the blue-green light region. that time,
The phosphor preferably has a wavelength range of 480 to 500 nm.
It has a luminescence peak at Ng is mainly used to increase the luminance of the phosphor, prevent deterioration of the phosphor during lamp baking, 1
It is included to prevent deterioration due to irradiation with 85 nm ultraviolet rays. For this purpose, the content of N is 0.01 to 1.0
gram atom, preferably 0.15 to 0.30 gram atom. X is a carrier of F, CI, Br or a mixture of two or more thereof, more preferably,
It is CI. Note that this phosphor has the favorable effect of absorbing the 4tlSn layer and the 438 nm H emission line, which are obstacles to obtaining high color rendering properties, and reducing the intensity thereof.

The second phosphor is a component that gives energy in the orange light region in the spectral energy distribution, and is a well-known phosphor that has a peak in the wavelength range of 820 to 1340 nm and has a half value of 111 of 120 to 1BOn-. Any such phosphor may be used, such as tin-activated strontium magnesium orthophosphate [(Sr
Ng) s (PO4) 2 :5111 is most preferred.

The third phosphor has an emission peak of 44ON.
BaMg2 All! in the 455 nm (7) region. 0
27: Alkaline earth halophosphates activated with Eu” and the same < lEu2+ [e.g. Sr5 (P
O4) 3Cl:Eu”.

(Sr, Ca) s (P 04) 3 C1: Eu”
, (Sr, Ca, Ha) c.

(P 04)3 C1: Eu”, (Ha, Ca, M
g) 5 (P 04) 3 CI:Eu 2+ etc.] are suitable. The reason is that they have high efficiency in a desired wavelength range and emit light with a small half-width.

The fourth phosphor activated with trivalent terbium is
(Os, Tb) MgAIu Oy, Y2Si
O5: Ce.

Tb, LaPO, :Ce, Tb, (La, Ce,
Tb) 203 e O,2SiO2・0.13 P2
O5 etc. are suitable. These are 545 with high visibility
It shows linear emission around nm.

As the fifth phosphor, La20s:Eu (Ln represents at least one element selected from the group of Y, La, and Gd) is suitable. Of these, Y203:E
u is most commonly used.

The fluorescent lamp of the present invention includes these first, second, third, and fourth fluorescent lamps.
and a fifth phosphor mixture is deposited on the inner surface of the glass tube.

The fluorescent lamp of the present invention can be obtained, for example, by the following method.

First, a predetermined amount of a first phosphor and a second phosphor are mixed together in a ball mill or the like to prepare a phosphor mixture I having the required color temperature or chromaticity point of a fluorescent lamp. do. The mixing weight ratio of the first phosphor and the second phosphor is usually 35:E15 to 50:50. With such a formulation, the color temperature will be around 5000''K.

Next, predetermined amounts of third, fourth and fifth phosphors are added to this phosphor mixture I and mixed thoroughly.

At that time, the mixing ratio of the third, fourth, and fifth phosphors is set to 100% of the phosphor mixture I consisting of the 3rd, 4th, and 5th phosphors.
It is preferable that I has the same color temperature or chromaticity point as the phosphor mixture I. Usually, 10 to 25 parts by weight of the third phosphor and 40 to 55 parts by weight of the fourth phosphor. and Phosphor Mixture I consisting of 25 to 45 parts by weight of a fifth phosphor is added to Phosphor Mixture I.

Further, the content of the phosphor mixture I in the total phosphor mixture is preferably 50% by weight or more. This is because if the content of the phosphor mixture is less than 50% by weight, the Ra of the fluorescent lamp will decrease.

The phosphor mixture thus prepared is then applied to a glass tube, for example by a known lacquering process, dried, fitted with a discharge electrode, evacuated the tube and mercury particles according to known methods. A fluorescent lamp of the present invention is obtained by filling the tube with argon gas and attaching a cap.

A lamp using only the phosphor mixture I of the first phosphor and the second phosphor used in the present invention exhibits a luminous flux of about 24001 m (5000"K, 40W) at Ra=99, and Mixture of third, fourth and fifth phosphors II
In the case of a lamp using only
Characteristics of 0-38001 intestines (5000"K, 40W) are shown.

Therefore, if we add to the phosphor mixture a phosphor mixture II which is designed to give substantially the same chromaticity as this:
Depending on the mixing ratio of (1) and H, a lamp with color rendering properties and efficiency intermediate between the above two types of lamps can be obtained. The lamps obtained in this way primarily belong to the 801 class and have a much higher efficiency compared to similar lamps known to date.

[Embodiments of the invention] Hereinafter, the fluorescent lamp of the present invention will be explained in detail by way of examples.

1-5 and l-2 Ba*Ca*Mg*P+CI and E
After weighing a predetermined amount of the u compound, the raw material mixture is
The mixture was ground and mixed in a Pall mill for 2 hours. The mixture was then sieved and placed in a quartz crucible, and fired in the atmosphere at a temperature of 850°C for 3 hours. The resulting fired product was cooled, pulverized, and sieved, followed by a mixture gas of 2% hydrogen and 8% nitrogen. Inside, 950
Secondary firing was performed for 1 hour at a temperature of °C.

This secondary fired product is cooled, crushed, sieved, washed, filtered, dried, and sieved to obtain the first phosphor Ba Ca Ng C1(PO4)3:Eu(0,1).
A powder of 4.1 0.5 0.3 was obtained, and the chromaticity, emission peak wavelength, and half-width of this first phosphor are shown in Table 1.The spectral energy distribution is shown in Fig. 1. Curve a is the spectral energy distribution curve of the first phosphor.

A second phosphor (Sr, Ng) is added to the obtained first phosphor.
3 (P 04) 2: When a lamp is made by mixing Sn, the chromaticity coordinate is approximately 5000”K, and the deviation is 0.0
03uv (x=0.345.y=0.3511) (7)
A phosphor mixture I was obtained. At this time, the weight ratio of the first phosphor and the second phosphor was approximately 40:80. Chromaticity of the second phosphor.

The emission peak wavelength and half-value width are shown in Table 1, and the spectral energy distribution is shown in FIG. 1. The curve in Figure 0 is the spectral energy distribution curve of the second phosphor.

Next, as the third phosphor, barium magnesium aluminate (BaMg2 A11g 027 :Eu) was used, and as the fourth phosphor, trivalent terbium activated lanthanum silicate (
La, Ce, Tb)2 o31+ 0.2Si02 m
0.9P205 + Select trivalent europium-activated yttrium oxide as the fifth phosphor, mix these three phosphors, and make a lamp with chromaticity coordinates of approximately 500.
0”K.

Deviation +〇, 005uv (x-0,348, y-0,38
A mixture ① of 3) was obtained. The chromaticity, emission peak wavelength, and half-width of these third, fourth, and fifth phosphors are shown in Table 1, and the spectral energy distribution is shown in Figure 2. Curves c, d, and e are shown in Table 1, respectively. It is a spectral energy distribution curve of the 3rd, 4th, and 5th fluorescent substance. Further, at this time, the weight ratio of phosphors 3.4 and 5 in mixture H is approximately 20:50:30.

Next, a mixture of the above-mentioned phosphor mixture and phosphor mixture (2) in various proportions was applied to the inner surface of a straight glass tube with a diameter of 32 mm and a length of 1200 mm, and then nitrocellulose was applied as a binder. According to the manufacturing method, the discharge electrode is installed, the tube is evacuated, mercury particles and argon gas are filled,
The caps were attached, and 40W fluorescent lamps of Examples 1 to 5 of the present invention were obtained.

For comparison, comparative fluorescent lamps (Comparative Examples 1 and 2) were also obtained using only the phosphor mixture I or ① in the same manner as above.

Next, photometric and colorimetric tests were conducted on the fluorescent lamps of Examples 1 to 5 and Comparative Examples 1 and 2. The results are shown in Table 2. Furthermore, as an example of the spectral energy distribution of the fluorescent lamp of the present invention, the spectral energy distribution of the lamp of Example 2 is shown in FIG. Shown separately from the continuous spectrum of the phosphor.

As is clear from Table 2, as the mixing ratio of phosphor mixture II increases, Ra decreases, but the total luminous flux increases. The total luminous flux was 22% higher than that of the fluorescent lamp of Comparative Example 1, reaching 29,301 points.

Also, compared to the lamp of Comparative Example 2, although the luminous flux is lower, the average color rendering index is higher, and the special color rendering index R9 and I? ts shows good values in all cases.

[Effect of the invention J] As is clear from the above explanation, the fluorescent lamp of the present invention has
It has the following effects: high color rendering properties, high efficiency, excellent special color rendering properties, and the ability to arbitrarily select combinations of efficiency and color rendering properties over a wide range, and its industrial value. is extremely large.

[Brief explanation of the drawing]

FIGS. 1 and 2 are characteristic diagrams showing an example of the spectral energy distribution of light emission of each component phosphor used in the fluorescent lamp of the present invention. In these figures, a. b, c, d and e are the spectral energy distribution curves of the first, second, third, fourth and fifth phosphors, respectively. FIG. 3 is a characteristic diagram showing an example of the spectral energy distribution of the fluorescent lamp of the present invention.

Claims (1)

[Claims] (1) General formula: M54X (P 04)3: Eu
”(x) (where M is 3.0 to 4.5 gram atoms of B
a and 0.5-2.0 gram atoms of Ca and 0.01-1.
represents an elemental mixture consisting of 0 gram atoms of Mg,
represents a single substance or a mixture of two or more of F, CI, and Br, and X represents a number in the range of 0.01<X≦0.2. a first phosphor comprising a metal helophosphate; 620
~B4on has an emission peak in the wavelength range, and 12
a second phosphor having a half-value width of 0 to 1B0 nm; a third phosphor activated with divalent europium and having an emission peak in the range from the 440n layer to 455n+w; and a third phosphor activated with trivalent terbium. a fourth phosphor that emits yellow-green light;
and a fifth phosphor represented by the general formula: La203:Eu (Ln represents at least one element selected from the group of Y, La, and Gd) is deposited on the inner surface of the glass tube. A fluorescent lamp featuring (2) The emission peak of the first phosphor is 480 to 500 n
A fluorescent lamp according to claim 1 having a wavelength range of m. (3) The third phosphor is divalent europium activated barium magnesium aluminate or has the general formula 2M=,zX
(P O4) 3: Eu” (ri (where M is C
a, Sr, Ba carrier or a mixture of two or more thereof; X is F; The fluorescence according to claim 1 or 2, which represents a carrier of CI or Br or a mixture of two or more thereof, and X represents a number in the range of 0.01<x≦0.2. lamp. (The fourth phosphor is (Ce, Tb)MgAIu O1!
+, Y2FiOr, :Ce, Tb, LaP O
4: Ce, Tb or (La, Ce. rb) 203 ” 0.25i02 ” 0.9 P
205 (1) Claim 1 which is any of (a);
The fluorescent lamp according to item 2 or 3. (5) Color temperature of the phosphor mixture consisting of the first phosphor and second phosphor, and color of the phosphor mixture H consisting of the third phosphor, fourth phosphor and fifth phosphor 2. A fluorescent lamp according to claim 1, wherein the temperature of the fluorescent lamp is substantially the same. (6) The content of the phosphor mixture in the total phosphor mixture is 5
The fluorescent lamp according to claim 1, wherein the fluorescent lamp has a concentration of 0% or more.