JPS60219290A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To provide a fluorescent lamp which has high efficiency and good appearance and whose starting voltage is low, by depositing a red light emitting phosphor where part of V of V2O3:Eu is substituted with La on a glass bulb. CONSTITUTION:A fluorescent lamp is obtd. by depositing a red light emiting phosphor of (V1-x, Lax)2O3:Eu obtd. by substituting part of V of a red light emitting phosphor of V2O3:Eu with La, on a glass bulb. The lamp has high efficiency and good appearance and its starting voltage is low. The phosphor contg. La in the range of La<=0.05g atom has higher efficiency than that contg. La in a quantity of La=Og atom.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to improvements in high efficiency fluorescent lamps.

[Technical background of the invention and its problems]

In recent years, there has been active development and improvement of fluorescent lamps with high efficiency and high color rendering properties, including three-liquid long-range fluorescent lamps. The high performance of fluorescent lamps is largely due to lamp design such as tube diameter and gas filling, as well as lamp manufacturing technology.
Improving the performance of phosphors is also an important element.

Various types of red-emitting phosphors have been developed and used in many fluorescent lamps.

As such a red-emitting phosphor, the europium-activated yttrium oxide phosphor Y2O3:Eu has higher efficiency than other red-emitting phosphors, is stable in the discharge space, and has a low luminous flux when used in a fluorescent lamp. It has good maintenance characteristics and is suitable for three-component long-range fluorescent lamps and calcium halophosphate phosphor 3C.
It is also used in daylight white fluorescent lamps mixed with a3 (PO4)2 Ca(FCM)2:Sb-Mn. Although Y2O3:Eu phosphor is such an excellent phosphor, other phosphors such as calcium halophosphate phosphor, cerium-terbium-activated lanthanum silicophosphate phosphor La2O3.0.25i02.0 .9P205:
Ce-Tb, cerium terbium activated lanthanum phosphate phosphor LaP04: Ce-Tb, europium activated barium magnesium aluminate t1 phosphor 3 (Ba
, Mg)0.8AM 203: Compared to Eu, etc., it releases impurity gases poorly, and has the disadvantage that the lamp starting voltage is higher than that of other phosphors. Furthermore, in the case of a curved tube lamp using soda-lime glass, mercury tends to adhere to the surface of the fluorescent film, resulting in an unsightly appearance.

[Purpose of the invention]

An object of the present invention is to provide a fluorescent lamp with high efficiency, low starting voltage, and good appearance.

[Summary of the invention]

By replacing a portion of Y in the Y2O3:Eu phosphor with lanthanum La, the disadvantages were improved without losing the advantages.

[Embodiments of the invention]

The present inventors have conducted various studies in order to further improve the luminous efficiency of Y203': Eu phosphor, release impurity gas well, and develop a red-emitting phosphor that is not contaminated by mercury. It has been discovered that by replacing a portion with La, the above-mentioned drawbacks can be overcome, and by adjusting the amount of La appropriately, the luminous efficiency can be further improved compared to Y2O3:Eu.

First, let's take the rated FLIIO5 type lamp as an example.

(Y, La) 203: Luminous efficiency was measured for samples with various amounts of La in Eu, and the results are shown in the figure. The amount of La determines the composition of the phosphor ('I'l-X, L
ax) 203: Shown as the value of X when expressed in Eu. In the figure, the horizontal axis shows the value of X, and the vertical axis shows the total luminous flux as a relative value, with X=O being 100, and one curve shows a correlation. -As is clear from this diagram, X is O
0.05 g atom, the luminous efficiency is equal to or higher than that of Y2O3:Eu. That is, O< x≦0.05
(g atom) is preferable from the viewpoint of improving luminous efficiency.

Next, this phosphor is mixed with the above-mentioned europium-activated barium-magnesium aluminate phosphor as a blue-emitting phosphor and the above-mentioned cerium-terbium-activated lanthanum silicophosphate phosphor as a green-emitting phosphor to achieve a color temperature of 50.
A 00K fluorescent lamp was constructed and the lamp characteristics were compared with a conventional lamp. The results are shown in Table 1 below.

Table 1 From this table, it can be seen that the lamp of this example has higher efficiency and superior starting characteristics than the conventional lamp. Note that the effect of improving the starting characteristics is also observed in the range of La>0.05 g atoms.

Next, this phosphor was mixed with a calcium halophosphate phosphor to form a fluorescent lamp with a color temperature of 5000 K, and the lamp characteristics were compared with conventional lamps. The results are shown in Table 2 below.

Table 2 It can be seen from this table that the lamp of this example has higher efficiency and superior starting characteristics than the conventional lamp.

Note that the effect of improving the starting characteristics is also observed in the range of La>0.05 g atoms.

Furthermore, in recent years, the material for the bulbs of annular fluorescent lamps has been shifting from conventional lead glass to soda lime glass. In general, triwavelength phosphors have smaller particle sizes than the conventionally well-known calcium halophosphate phosphors, making it difficult to discharge impurity gas from within the fluorescent lamp. In particular, it is said that when soda lime glass is bent into a bulb, alkali precipitates and reacts with the phosphor and mercury, reducing the performance of the fluorescent lamp. This phenomenon is particularly noticeable in lamps using phosphors containing y2'03:Eu in the forewater.

A few hours after lighting, mercury-like deposits tend to form near the coldest part of the lamp, which not only looks unsightly, but also
This was also a negative factor in terms of performance. However, when (Y, La) 203 :Eu according to the present invention was used, this phenomenon was not observed and good results were obtained. The reason for this is thought to be that the introduction of La improved the degassing properties of impurity gases, and this effect was noticeable even in a wide range beyond the above-mentioned x=0.05 g atom.

Note that the present invention has similar effects even when applied to a red fluorescent lamp using only a red-emitting phosphor.

〔Effect of the invention〕

The fluorescent lamp of the present invention replaces a part of Y in Y2O3:Eu with L.
Since a phosphor substituted with a is used, the starting voltage is low, the appearance is good, and the efficiency is higher in the range of La amount of 0.05 g atoms compared to the case where La=Og atoms.

[Brief explanation of drawings]

The figure shows (L La) 203 used in the fluorescent lamp of the present invention.
: is a graph showing a particularly preferable range of the amount of La in Eu. Agent Patent attorney Inoue-Ochi (tD 7Ar) Procedural amendment (spontaneous) Kazuo Wakasugi, Commissioner of the Japan Patent Office (Monday, Showa)1, Indication of the case: Patent Application No. 75699 of 1982, Name of the invention: Firefly Light lamp 3, relationship with the case of the person making the amendment Patent applicant (307) Toshiba Corporation 4, Agent No. 41-11, Kamata 4-te, Ota-ku, Tokyo 144 - Tsunoda Pill Benjo Patent Office 5, As shown in Column 6 of the scope of claims of the specification to be amended, the content of the amendment is as shown in the appendix. Claims (1) 'Y, 03: A fluorescent lamp characterized in that a red light-emitting phosphor represented by the chemical formula Eu in which part of Y is replaced by La is adhered to a glass bulb. (2) The phosphor composition is (Yl-X p Lax )t
Os : ”, the value of X is Q(x≦0.05
A fluorescent lamp according to claim 1, characterized in that: (3) A fluorescent lamp according to claim 1 or 2, characterized in that a red-emitting phosphor is adhered to a glass bulb together with other phosphors.

Claims (3)

[Claims] (1) Y2O3: In the chemical formula El, part of V is replaced by L
A fluorescent lamp characterized in that a glass bulb is coated with a red light-emitting phosphor represented by a. (2) Phosphor composition (Y t-x r LaX) 20
a: When expressed in Eu, the value of X is O< x≦Q, O
05. The fluorescent lamp according to claim 1, wherein the fluorescent lamp is 05. (3) A fluorescent lamp according to claim 1 or 2, characterized in that a red-emitting phosphor is adhered to a glass bulb together with other phosphors.