JPS60135477A - White light-emitting phosphor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Recently, as small electronic computers have become widespread in various fields such as information processing, numerical control, design, education, office rationalization, and entertainment, the demand for cathode ray tubes for display devices has expanded dramatically. Currently, monochromatic cathode ray tubes use green, black and white, and yellow to orange phosphors, but orange and black and white displays are expected to become mainstream in the future due to their ease of viewing and ease of eye fatigue. . In addition to the above-mentioned color development, the characteristics required of cathode ray tubes for display devices include brightness and no flickering. In particular, in the case of cathode ray tubes for display devices, the sweep frequency of the electron beam is often lower than that of cathode ray tubes for televisions, so the screen will flicker unless a long afterglow phosphor is used. However, in general, phosphors have a characteristic that their brightness decreases significantly when they have a long afterglow, so it is difficult to obtain a phosphor with a long afterglow and high brightness. A phosphor with a single composition that almost satisfies this criterion is Zn2 St 04 : Mn green phosphor (1/10 afterglow time r, 7.. = 40-50 m
5ec) and 3Cd3(PO4)z・cdcIlz:M
n orange phosphor (τi/lo = 30m5ec) I
) only. In the case of black and white display, the required white color is usually CIE
(International Commission on Illumination) 0.2 (x,
A blue-white color with y < 0.3 is used, but there are no single composition, high brightness phosphors in this chromaticity coordinate region. Therefore, the mixed white phosphor was made of Zn25i04:Mn in consideration of the necessary characteristics of the phosphor for cathode ray tubes for display gray equipment.
Or 3 Cds (PO4)z ・CdC6z:
It is customary to use it as a part of the Mn k mixed material. However, since the complementary color phosphors (blue, red) of these long afterglow phosphors have a short afterglow (τ - several to 1/10 several + μ5ec), the mixed color may cause color unevenness during the decay process after excitation is stopped. There is a drawback that flickering occurs, and conversely, the brightness must be lowered to suppress color unevenness and flickering. In addition, when using the above-mentioned (support) type phosphor, a strict collection system must be adopted to suppress the discharge of harmful substances, which has the added disadvantage of becoming a major factor in increasing costs.

The mixed white phosphor of the present invention was developed to overcome all the drawbacks of the above-mentioned phosphors for cathode ray tubes in display devices.

In order to meet the above object, in the present invention, the general formula is Ca, aM
gaS : Mn (0≦α(0,04)) and an orange phosphor expressed by the general formula Ca, -, Mgp S : C
CIE by mixing u, A (0 < β (0, 04, A yo Na or K) with a blue phosphor
Chromaticity coordinate (x.

y) 0.2 (x, y (0,4) A high brightness afterglow phosphor capable of developing a white color in the range of 0.2 (x, y (0,4) is disclosed.

In this phosphor, (1) the luminous efficiencies of the orange and blue phosphors are almost equally high (14 to 17%), and therefore the luminance is high even in the mixed white region. The color above is orange.

In the region where the composition ratio α, β in the blue phosphor is 0605 or more, the decrease in luminous efficiency and the decrease in chemical stability are noticeable, so it is not used in the mixed white phosphor material. (2) The above orange and blue colors The +1 phosphor shows the same excitation current-luminance characteristics, and the remaining ones also have a mixed composition of 0.15≦Ca1. Mga
S: Mn(0'F;;, a (0,04)≦0.
Since it exhibits fusion characteristics in the area of 7, color unevenness and flickering do not occur. In other words, Ca
, -aMgaS: Mn (0<α<0.04), the afterglow time changes between 5m5ec<, τ1/1o≦12m5ec, and “al-pMgps:Cu, A(0≦β
At (0,04), 8m5ec<τ+/+o ri25m
It changes with sec. When various combinations were changed and tested, this mixed white phosphor showed a value of 0.1 as shown in Figure 1.
5≦Ca, -aMgaS: Mn (0≦a (0,
04) < 0.7 range is 0.2 (x, y (
It mostly overlaps with 0 and 4, and in this region it shows fusion type characteristics and no color unevenness is seen in the afterglow color after excitation stops.
It was found that in other composition ranges (mixed compositions of 85 moA!% or more of blue phosphor or 70 moA!% or more of orange phosphor), self-assertive characteristics were exhibited and blue unevenness or orange unevenness was produced. Therefore, the overlapping region shown in FIG. 1 is a preferred mixed white phosphor composition (claimed scope). (3) It does not contain harmful substances or precious metals, resulting in a cost advantage. Because of these features, the above problems are solved, but in addition to these, (4) matrix composition ratios α, β
As shown in Figure 81, the chromaticity coordinates of the phosphor before mixing can be changed considerably depending on the concentration of the activator, so there is an advantage that the display of the mixed white color can be precisely controlled over a wide range. The range 0.2 (x, y (0,4) includes blue-white to warm-white, giving the user a wide range of choices.

The present invention will be described in detail below based on Examples.

(Part 1) CaS with a particle size of 5 μm calcined in hydrogen sulfide using calcium carbonate and manganese sulfide as starting materials:
Mn (0.1 mo1%), calcilum carbonate, magnesium carbonate, sodium carbonate, and oxidized steel were used as starting materials and calcined in hydrogen sulfide with a particle size of 5 μm 0) Ca,
,,.

Mgo,otS: Cu (0.1mol1%),
A white phosphor was prepared by mixing Na (2.3 mo1%). CaS: Mn (0.1mol1%) as phosphor A
,”(1,99Mgo,oi8: Cu(0,
1mrr1%) and Na (2,3mol1%) as phosphor B, the chromaticity coordinates of phosphors A and H are (x,
y)=(0,524,0,477), (X.

V) = (0,136, 0,182). When phosphors A and B are mixed in an appropriate ratio, a mixed white phosphor as shown in Table 1 is obtained in the range of 0.2 (x, y (0,4).The data in Table 1 is It shows the chromaticity coordinate values and luminous efficiency (absolute energy efficiency expressed in %) at room temperature when excited with t-rays at an accelerating voltage of 20 KV.

Fluorescent material A was measured under the same excitation conditions as in Table 1.

The luminous efficiency of B was 17% and 17.8%, respectively.

In addition, the mixed white phosphor shown in Table 1 has an afterglow time of τ17.
, o is 13.5 to 14.2 m5ec, and it exhibits the fusion type characteristics of A and B. Therefore, no color unevenness or flickering was observed even when it was applied to a 12-inch cathode ray tube face plate and displayed by sweeping at a repetition frequency of 45 Hz. There wasn't.

Table 1 Mixed white characteristic values (Il (Part 2) Lucium carbonate, Magnesium carbonate,
"o,ayMgo,osS" with a particle size of 4 μm is obtained by repeatedly sulfiding the manganese sulfate raw material in a hydrogen sulfide atmosphere.
: Mn (0.5 blood 1%) (hereinafter referred to as phosphor C) was fired.

Also calcium sulfate, magnesium sulfate, copper sulfate,
Cao, wsMgo, with a particle size of 4 μm, was similarly sulfurized in a hydrogen sulfide atmosphere as a raw material for potassium carbonate.

s S NiCu (0-1rr1O1%), K (2m
oj? %) C or less fluorescent material D) k fired. Fluorescent material C,
The chromaticity coordinates of D are (x, y) = (0,
565,0,432), (x,y)=(0,136
, 0,242). Fluorescent materials C and D were mixed in an appropriate ratio and applied by precipitation to the face plate of a 15-inch cathode ray tube, and the fluorescent properties were measured at room temperature by excitation with a 14 KV electron beam. The characteristic values of the mixed white color are phosphors C and D.
Table 2 shows a comparison. Furthermore, as shown in FIG. 2, the dependence of the luminance on the excitation current is 10.84 to 0.88. In other words, phosphors C and D and the mixed white phosphor shown in Table 2 all exhibit saturation characteristics that are almost the same in the operating current range of cathode ray tubes for display devices. Also, the afterglow time of phosphors C and D is τ71g=5.5m5eC, respectively.
However, in the case of the mixed white phosphor shown in Table 2, it was approximately constant at 14.5 m5ec. These mixed white phosphors did not cause any color unevenness in the displayed image.

The data in Table 2 and Figure 2 are 0 based on the combination of C and D.
,2 (x, y This shows that it has sufficient luminous efficiency as a cathode ray tube.

Table 2 Characteristic values of mixed white phosphor (Ill (Part 3) Calcium carbonate, magnesium sulfate.

Ca with a particle size of 6 pm as a total raw material for manganese oxide and hydrogen sulfide
o, e9 Mgo, o, S: Mn (0,2mo
1%) was completely fired. Similarly, CaS:Cu (0.15mol1%
Na and CaS: Cu (0,15rr1
01%), and was fired to 2'. C.B. ,99Mg0,o,
S: Mn (0.2mal1%) (hereinafter referred to as phosphor E
) is (x, y) = (0,540°0
．． 459) and τ = 9.5 m5ec.

Also, CaS: 1/10 Cu (0.15rmj?%), Na (hereinafter referred to as phosphor F)
The chromaticity coordinates and afterglow time of CaS:Cu (0.15 mo/%) and K (hereinafter referred to as phosphor G) vary greatly with the Na or K content concentration. Fluorescent body K'k 30m
o1%, phosphor F (or G, or a mixture of F and G)
K 70rr+J% and mixed white phosphor was applied to all 12 inch cathode ray tube face grates and 14KV
The fluorescence properties at room temperature when excited with an electron beam are shown in Table 3.

The chromaticity coordinates of the blue phosphor listed in Table 3 are approximately the same as those of a cathode ray tube, using a test sample obtained by depositing KF (or G, or a mixture of F and G) on a glass plate. Measurements were made under these conditions to generate electron beam excited luminescence. The data in Table 3 shows that uneven afterglow occurs when the color coordinate (y value) of the white phosphor is smaller than 0.2;
It is shown that color unevenness does not occur in the region of < y < 0.4. Although not shown in this example, x, y
It was shown that afterglow unevenness occurs even in the color coordinate region of 20.4 and Or y is 0.
In areas of 4 or higher, orange unevenness is noticeable. K, the mixed white phosphor of the present invention as described in the above embodiments of the present invention? When used, it is possible to realize a gray to warm white display without high brightness one-color unevenness or flickering at 1° brown for display equipment.

In the example, only the electron beam excited fluorescence characteristics were described, but the mixed white phosphor was almost colored by ultraviolet light (2537AHg).
line) can be used as an excitation phosphor.

A simple explanatory diagram shows the scope of claims of the present invention, and Figure 2 is a diagram showing the relationship between electron beam excitation current and emission brightness in an example of a non-explosion surface.The patent applicant is a representative of Rare Metallic Co., Ltd. Patent attorney Tadashi Akimoto Substantive procedural amendment (spontaneous) Date of 1980-Monday Kazuo Wakasugi Director General of the Patent Office 1, Indication of the case 1966 1V Patent Application No. 2V Co. IB No. 2, Title of the invention White f' Body 3, relationship with the corrector R1 1. i #Templen1JJ Applicant address (residence) 2-chome, Misaki-cho, Chiyoda-ku, Tokyo Number/No. Name: Rare Metallic Co., Ltd. 4, Agent 5, Date of amendment order Showa Year, Month, Day 1, Request for % allowance Correct the range as shown in the attached sheet.

2. Lines 7 to 7 on page G of the present specification are corrected as follows.

r 0-15<Ca1 a MgαS :Mn(0≦α
<0.04) <0.7 region, i.e. orange phosphor ca,
-aMgα:Mn mixed molar ratio in the composition range of 0.15 to 0.7 causes color unevenness and flickering in order to exhibit fusion characteristics.'' 3. Correct the above, page G, lines is to 16 as follows. .

[Orange phosphor”1-a Mga S :Mn (However,
The composition with a mixing molar ratio of 0.15 to 0.7 of α<4) is:
0.2<x, y<0,4, and this "4. Figure 1 of the drawing is corrected as shown in the attached sheet.

Claims 1. The general formula is CJ a Mga S : Mn (0<
α < 0.04) and the general formula is C
a1-βMgβS:Cu.

By mixing A (0 x β < 0.04. A white phosphor that embodies white thread coloring in the overlapping region of .4 and the orange phosphor formation range.

Claims (1)

[Claims] 1. The general formula is Ca I-a Mgas : Mn (0
The orange phosphor expressed as < a (0,04) and the general formula are Ca 1p Mgp S :Cu, A(0≦β(0,
0.04, A (3 Na or K) with a blue phosphor displayed in CIK chromaticity coordinates (x, y).
2 (x, y (range of 0,4 and 0.15≦Ca1
- aMgaS: A phosphor that embodies white coloring in an area overlapping with the Mn ratio of 0.7.