JPS5986686A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To provide a fluorescent lamp which has a fluorescent film consisting of a Cs-containing Sb/Mn-activated halophosphoric acid fluophor and an Eu- activated yttrium oxide fluophor and shows minimized color drift and darkening of lamp tube ends while it is on. CONSTITUTION:A mixture of an Sb/Mn-activated halophosphoric acid fluophor containing 6wt% or less Cs and having an average particle diameter of 3-10mum and an Eu-activated yttrium oxide fluophor having an average particle diameter of 0.5-5mum is applied to the inner surface of a glass tube by known methods to form a fluorescent film. EFFECT:The fluorescent lamp having the above fluorescent film shows no color drift nor darkening of lamp tube ends even after 3,000hr of service.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to improvements in fluorescent lamps.

[Technical background of the invention and its problems] 8b and Mn-activated calcium halophosphate phosphors (hereinafter referred to as calcium halophosphate phosphors) have relatively high luminous efficiency and emit light colors ranging from warm white to blue. It has advantages such as being variable and inexpensive, but it has a disadvantage of poor color rendering for red.

In order to improve the color rendering properties of calcium halophosphate phosphors for red, many methods are known in which phosphors that emit light from orange to red are mixed and used.

In recent years, fluorescent lamps using a mixture of calcium halophosphate phosphor and CRu-activated yttrium oxide phosphor (hereinafter referred to as yttrium oxide phosphor) (10 or less) are relatively slow and have a 1-1 However, the color of this fluorescent lamp becomes more reddish while the lamp is on, which is a so-called color shift phenomenon, which reduces its commercial value. It has decreased significantly.

This phenomenon is caused by the difference in the rate of decrease in the luminous output of the two-value luminescent material during lighting of the d' lamp, and the rate of decrease in the luminous output of the calcium halophosphate phosphor is (, It shows that it is larger than the body.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluorescent lamp in which color fading and blackening at the end of the lamp tube are improved during lamp operation.

[Summary of the invention]

The present invention is characterized in that it is equipped with a phosphor film composed of a cesium-containing Sb and Mn f'j active halophosphate phosphor (hereinafter referred to as halophosphate phosphor) and a yttrium oxide phosphor. do.

5000K daylight white fluorescent light σ300 according to the present invention C1
Even when the 0 o'clock exit η is lit, the luminous color shank 2 can hardly be seen.

In contrast, a halophosphoric acid phosphor containing no Ce and a K
The deviation in the emission color of a comparative fluorescent lamp equipped with a fluorescent film made of a u-activated yttrium oxide phosphor is expressed by the CIE chromaticity coordinate x,
In y, X is 0.012.ノ・“How to listen Cs, Vke0
．． 001 It was confirmed that it was shifted towards the smaller side and towards the red side.

Further, in the fluorescent lamp of the present invention, blackening at the end of the lamp tube after 3000 hours of operation is greatly improved.

Tube end blackening refers to the so-called blackening phenomenon in which the end of the lamp tube turns black while the fluorescent lamp is on.When this phenomenon occurs, the appearance of the lamp is significantly impaired and its commercial value is significantly reduced. Blackening at the tube end occurs under the activation state of radiation 1:, and varies depending on the type of phosphor, substances scattered from the cathode, impurity gas inside the tube, etc., but the occurrence position is always C':, Fixed position near the electrode ○ To evaluate the degree of tube end blackening, sample fluorescent lamps with different degrees of tube end blackening were prepared, and the points attached to the sample lamps were displayed. The maximum degree of tube end blackening was given a score of 0 (zero), and the case with no tube end blackening at all was given a score of 10, and the range between these points was classified into IO levels.

A score of 5 was set as a score that does not pose a practical problem.

The above-mentioned 5000K daylight white fluorescent lamp had a score of 7 points and 1''' for tube end blackening after being lit for 3000 hours.
On the other hand, the fluorescent lamp according to the present invention received a score of 3.0 When the total amount of aS contained in a halophosphate phosphor exceeds 6, the luminous output decreases compared to one that does not contain it. . Furthermore, C2, halophosphate phosphor and oxide) IJ
If the average 1.11 diameter of the phosphor is smaller than 3.05 μm, the luminous output of the fluorescent lamp will be low; if it is larger than 5 μm, the 1111 rating of the light lamp will be high. This is preferable from a practical standpoint.

The average particle size in the present invention was determined by an aeration method (air permeation method).

The effect of the present invention is that by incorporating Ce into the halophosphate phosphor, the degree of reduction in luminous output during lighting of the fluorescent lamp is made to be the same as that of the IJium phosphor, and further,
By increasing the crystallinity, it becomes a chemically and physically stable phosphor, which is thought to improve the tube end blackening of fluorescent lamps.

Halophosphoric acid containing Os
aHPO4+ 0aCO9, cacJ)B, 0aF2
+ NH40J+ 5b20B, 0s for Mn0OB etc.
It can be obtained by adding and mixing a desired amount of a substance such as BOOB, CaO, CaN0B, etc. that generates cesium oxide or cesium phosphate at high temperatures, and then following a known and usual method for producing a halophosphate phosphor.

In order to prevent the fluorescent film from peeling off or falling off, oxides, phosphates, borates, etc. can be used in combination with the fluorescent material, or
When the glass tube material of a fluorescent lamp contains a relatively large amount of C disodium, the inner wall of the glass tube and the fluorescent film may be mixed with dimetallic oxides, It is known to form a film of phosphate, etc.
Even in such a case, the effects of the present invention are not limited in any way.

[Embodiments of the invention]

Hereinafter, C2 will be explained in more detail using Examples.

Example 1 Calcium halophosphate phosphor containing 06 with an average particle size of 6 μm and 0.3:Iit'i% (emission color 5400K)
97v, 3t of IJum phosphor with an average particle size of 2μm was mixed, and 40W of 500
A daylight white fluorescent lamp was prepared in Example 0 and used as an example fluorescent lamp.

It has a double average particle size of 6 μm and does not contain cesium.
Mix IF acid calcium phosphor (emission color 5400K) 972 with IJium oxide phosphor 3F (with an average particle size of 2 μm) and prepare a daylight white fluorescent lamp of 5000 at 40 watts according to the following conventional method. This was used as a comparative fluorescent lamp.

Examples and Comparative Examples Both fluorescent lamps 1: The luminescent color at the initial stage of lighting and the luminescent color of the lamp after 3,000 hours of lighting were measured to determine the degree of one-color difference. The results are shown in Table 11.

If the difference between the lamp emission color C1■, E color V at the initial stage of lighting and E chromaticity after 3000 hours of lighting (!, 1. The degree of this is $ = 0.012, 3+ = 0.001, and the color is shifted toward more reddish.

On the other hand, the color shift of the example fluorescent lamp is X=0.00.
2, y=0.000, and considering the test error, it can be said that there is almost no color shift.

Honored. The degree of blackening of the tube end of the fluorescent lamp of the comparative example was 7 points C2, while that of the example fluorescent lamp was 3 points, and the degree of blackening of the tube end was revised to 7 points C2.

Example 2 Calcium strontium halophosphate phosphor (emission color 68
00K) 9sr, 5t of yttrium oxide phosphor with an average particle size of 3μm was mixed, and then 40W of 6
A 500 K daylight color fluorescent lamp was prepared and used as an example fluorescent lamp.

In addition, Halo# has an average particle size of 4 μm and does not contain cesium.
Calcium acid strontium phosphor (emission color 6800
K) 95t was mixed with 5f of yttrium oxide phosphor having an average particle size of 3 μm, and then 40W of 65t was mixed in accordance with the usual method.
A 00K daylight color fluorescent lamp was prepared and used as a comparative example fluorescent lamp.

Implementation $11. Comparative example: 5 double fluorescent lamps, 3 initial lighting times
The color of the emitted light at two times and the color of the emitted light after 3,000 hours of lighting were measured to examine the degree of color fading. The results are shown in Table 152.

If the difference between the C0, E chromaticity of the lamp emission color at the initial stage of lighting and the O, vFix=o, 007, y=0.001, and the color is shifted toward the reddish side.

In contrast to this (2), the color shift of the example fluorescent lamp is X=0.0
02, y=0.000, and when test errors are taken into consideration, one color shift is extremely unlikely.

Further, the degree of blackening at the end of the tube in the fluorescent lamp of the comparative example was 6 points, whereas the fluorescent lamp of the example had a degree of blackening of 3 points, which was a great improvement.

Claims (1)

[Claims] ° (1) Antimony (sb) containing cesium (Cθ)
), a manganese (Mn)-activated halophosphate phosphor, and a europium (GU)-activated yttrium oxide phosphor. (2) The fluorescent lamp according to claim 1, characterized in that it contains 6% by weight or less of cesium based on the antimony and manganese activated halophosphate phosphor. (8) The average particle size of the antimony and manganese-activated halophosphate phosphor is 3 to 10 μm (micrometers), and the average particle size of the europium-activated yttrium oxide phosphor is 0.5 to 5 μm. A fluorescent lamp according to claim 1, characterized in that: