JP3245885B2 - Fluorescent lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

 [Object of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-wavelength fluorescent lamp.

[0002]

2. Description of the Related Art A three-wavelength fluorescent lamp has a wavelength of about 450 ± 1.
Blue light-emitting phosphor having an emission peak at 5 nm, wavelength 5
High efficiency and high color rendering properties are achieved with a fluorescent lamp provided with a fluorescent film comprising a green light emitting phosphor having an emission peak of 45 ± about 15 nm and a red light emitting phosphor having an emission peak at a wavelength of 610 ± about 15 nm. It was developed to make them compatible.

[0003]

In recent years, it has been pointed out that the above-mentioned conventional three-wavelength fluorescent lamp has excellent brightness but insufficient color rendering properties, and further improvement is required. Reached.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. Hei 1-186749, a trivalent europium-activated strontium aluminate phosphor and a divalent europium-activated phosphor are used in place of the above-mentioned blue light-emitting phosphor. It is known to use a strontium acid phosphor or a divalent europium activated calcium / barium / magnesium phosphor. However, although the color rendering properties of the three-wavelength fluorescent lamp were improved, the brightness was significantly reduced.

Therefore, an object of the present invention is to solve the above-mentioned problem with the above-mentioned Japanese Patent Application No. Hei.
It is an object of the present invention to provide a fluorescent lamp in which the sacrifice of brightness is minimized as compared with the three-wavelength fluorescent lamp disclosed in Japanese Patent No. 186749, and color rendering is improved.

[Configuration of the Invention]

[0007]

The present invention provides a three-wavelength fluorescent lamp in which a fluorescent film has a first emission peak between 445 and 455 nm and a second emission peak between 510 and 520 nm. A first phosphor composed of europium / manganese co-activated barium / magnesium / aluminate having a specific relationship between the two emission peaks;
A second phosphor made of europium-activated yttrium oxide having an emission peak near 0 nm, and a wavelength of 545 n
and a third phosphor co-activated with cerium and terbium having an emission peak near m.

[0008]

In a three-wavelength fluorescent lamp, the color rendering property and the brightness are in a trade-off relationship. For example, if the ratio of the phosphor component is changed to increase the brightness, the color rendering property is greatly reduced. However, in the present invention, the europium-activated calcium / barium / magnesium phosphate phosphor (blue-green light emission) in the prior art is replaced with a europium / manganese co-activated barium / magnesium / aluminate phosphor, so that the brightness is sacrificed. Was minimized and color rendering was improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been studied for improving the color rendering of a three-wavelength fluorescent lamp. The present invention is used for other special purposes instead of the europium-activated calcium / barium / magnesium phosphate which is a conventional blue-green light emitting phosphor. The present inventor has conceived of using a first phosphor made of divalent europium / manganese co-activated barium / magnesium / aluminate.

As can be seen from the spectrum diagram shown in FIG. 1, the first phosphor has a first emission peak at around 450 nm due to divalent europium and a second emission peak at around 515 nm due to manganese. And a co-activated phosphor having an emission peak of And Japanese Patent Application Laid-Open No. 58-2249.
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. 6 (1994), by changing the compounding ratio of europium and manganese, the intensity ratio p2 between the first emission peak P1 and the second emission peak P2 is changed.
/ P1 can be changed continuously.

Therefore, the first phosphor obtained by varying the intensity ratio p2 / p1 of the two emission peaks of the above-mentioned divalent europium / manganese co-activated barium / magnesium / aluminate phosphor is conventionally known. Similar to the second phosphor (red emission) made of europium-activated yttrium oxide having an emission peak near 610 nm, which is known for a three-wavelength fluorescent lamp, cerium having an emission peak near 545 nm for three wavelengths as in the second phosphor. A straight tube type 40 adjusted to a correlated color temperature of 5000 K by combining with a third phosphor (green light emission) made of terbium co-activated lanthanum phosphate
W fluorescent lamps were manufactured and their characteristics were evaluated.

In addition, as a conventional example corresponding thereto, a europium-activated calcium-barium-magnesium phosphor (blue-green light emission) having a known emission peak near a wavelength of 483 nm and a europium-activated barium-magnesium-aluminum are known. And the above-mentioned second phosphor that emits red light and the above-mentioned third phosphor that emits green light. A straight tube 40 W fluorescent lamp adjusted to a correlated color temperature of 5000 K was produced in combination, and their characteristics were evaluated.

First, in the above-described embodiment of the present invention, the intensity ratio p2 / p of the first and second emission peaks of europium / manganese co-activated barium / magnesium aluminate is used.
By changing 1 in various ways, the relationship between the color rendering properties and the brightness of the fluorescent lamp at that time was measured. The result is shown in FIG.
In the figure, the horizontal axis indicates the value of p2 / p1, and the vertical axis indicates the average color rendering index Ra and the total luminous flux ratio (%). The solid line-indicates the average color rendering index Ra, and the broken line- -Indicates the total luminous flux ratio. As is apparent from this figure, when p2 / p1 is increased, the color rendering properties are improved, but the brightness is conversely reduced.

Next, with respect to the above-mentioned present invention example and the above-mentioned conventional example, the present invention example changes the intensity ratio p2 / p1 of the emission peak to thereby obtain the europium-activated calcium-barium-magnesium fluorescent material. The correlation between the color rendering properties and the brightness of each lamp was investigated by changing the mixing ratio of the body and the europium-activated barium / magnesium / aluminate phosphor. The result is shown in FIG. In the figure, the horizontal axis indicates the average color rendering index Ra, and the vertical axis indicates the total luminous flux ratio of the lamp in units of%. The solid line indicates the correlation of the present invention and the broken line indicates the correlation of the conventional example. Show. As is clear from FIG. 3, it was found that the example of the present invention was brighter than the conventional example when the average color rendering index Ra was 83 to 88. Therefore, when a range brighter than the conventional example in this embodiment, that is, a range in which the average color rendering index Ra is 83 to 88 is applied to FIG. 2, the intensity ratio p2 / p1 of the emission peak is in the range of 0.2 to 0.5. If there is, it turns out that it is brighter than before.

Accordingly, in the present invention, the first phosphor has a first emission peak between 445 nm and 455 nm, a second emission peak between 510 nm and 520 nm, and the first phosphor. The intensity ratio p2 / p1 between the peak p1 and the second emission peak p2 is 0.2 to 0.5.
5, a europium / manganese co-activated barium / magnesium / aluminate phosphor. The second phosphor is a conventional europium-activated yttrium oxide phosphor having an emission peak near a wavelength of 610 nm, and the third phosphor is a variety of cerium-terbium coactivation having an emission peak near a wavelength of 545 nm. It was a phosphor. The variation in the peak wavelength of the first phosphor is within a range that does not hinder the operation and effect. In the second and third phosphors, the peak wavelength is allowed to be ± 15 nm.

In the present invention, the color temperature of the lamp may be set as desired by changing the ratio of the three-component phosphor, and the three-component phosphor may be replaced with a phosphor of another emission color. Can be adjusted to adjust the chromaticity, Ra, special color rendering index Ri, and the like. In the present invention, the three-component phosphors may be mixed and applied, or may be applied by lamination.

[0017]

As described above, the present invention provides a three-wavelength fluorescent lamp having a first emission peak p1 between 445 and 455 nm and a second emission peak p2 between 510 and 520 nm. And the intensity ratio of the two emission peaks p2 /
a first phosphor comprising a bivalent europium / manganese coactivated barium / magnesium / aluminate having p1 of 0.2 to 0.5, and a conventional europium activated having a light emission peak near a wavelength of 610 nm A second phosphor made of yttrium oxide and a third co-activated cerium-terbium having a light emission peak near a wavelength of 545 nm in the related art.
Since the phosphor film was composed of the phosphor described above, it succeeded in improving the color rendering properties while minimizing the sacrifice of brightness.

[Brief description of the drawings]

FIG. 1 is an emission spectrum diagram of an example of a divalent europium / manganese coactivated barium / magnesium / aluminate phosphor used in a fluorescent lamp of the present invention.

FIG. 2 is a graph showing the relationship between the intensity ratio of both emission peaks of a first phosphor and the color rendering properties and brightness of a lamp in the present invention.

FIG. 3 is a graph showing the relationship between color rendering and brightness in the fluorescent lamp of the present invention and a conventional fluorescent lamp.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 61/44

Claims (1)

(57) [Claims] 1. A fluorescent lamp having a fluorescent film formed on an inner surface of a bulb, wherein the fluorescent film has a wavelength of 445 nm to 455 nm.
nm, a second emission peak between 510 nm and 520 nm, and an intensity ratio between the first emission peak and the second emission peak is 0.2 to 0.2 nm. 0.5 of europium / manganese co-activated barium / magnesium / aluminate
A second phosphor made of europium-activated yttrium oxide having a light emission peak near a wavelength of 610 nm, and a third phosphor co-activated with cerium and terbium having a light emission peak near a wavelength of 545 nm. A fluorescent lamp comprising a phosphor.