JPS5971385A - Method for treating fluorescent substance - Google Patents

Abstract

PURPOSE:To improve the luminance of a fluorescent substance, excitable with slow electron rays, and used for fluorescent display tubes, etc., by bringing metallic zinc into contact with a fluorescent substance, and irradiating the fluorescent substance with fast electron rays at such a level as to recoil the zinc atom. CONSTITUTION:For example, a fluorescent substance 2 of ZnO:Zn is placed on a quartz glass plate 1, and a metallic zinc plate 3 having 0.2mm. thickness is further placed thereon. The zinc plate 3 is then irradiated with fast electron rays accelerated in an electron ray accelerator from above at 7 MeV and 5X10<17> electrons/cm<2> intensity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phosphor processing method for improving the brightness of a low-speed electron beam-excited phosphor used in a fluorescent display tube or the like.

The phosphor used in fluorescent display tubes is generally ZnO:Zn phosphor, which can provide bright brightness at low voltage.
This exhibits blue-green luminescence. In recent years, ZnS that emits blue light has been used as a material that emits light in a color other than blue-green:
AtrC1% Emit red or orange light (ZnCd
)S:Ag,C-1%ZnS exhibiting yellow luminescence
: Fluorescent materials such as AueAL have been proposed.

However, these phosphors have a disadvantage in brightness compared to blue-green phosphors, and a phosphor that can provide bright luminance is desired. Furthermore, even with conventionally used phosphors exhibiting blue-green color, if brighter light emission can be obtained, the anode voltage can be lowered, which is also preferable from the standpoint of miniaturization and energy saving.

Therefore, an object of the present invention is to provide a novel phosphor treatment method that can improve luminance.

In order to achieve this object, the present invention mixes metallic zinc having a size sufficiently larger than the particles of the phosphor powder in the phosphor, and irradiates the phosphor with a high-speed electron beam. Hereinafter, the present invention will be described in detail using drawings showing embodiments.

FIG. 1 is a diagram showing a state in which a phosphor is being processed by applying the phosphor processing method according to the present invention.

In the figure, 1 is a quartz glass plate, on which is placed a ZnO:Zn phosphor 2 to be processed, and on top of the phosphor 2 is a metal zinc plate 3 with a thickness of 0.2 mm. is listed. A high-speed electron beam accelerated by an electron beam accelerator and shown by an arrow is irradiated onto the thus arranged object from above, that is, from the side of the zinc plate 3. In the example, 5 x 10" at 7 MeV
electron/c! 1 irradiation is being carried out.

An anode having a fluorescent surface formed using the phosphor 2 treated in this way and an anode having a fluorescent surface formed using the untreated phosphor are used, respectively. Then, a fluorescent display tube with multiple anodes was formed and the luminance was measured. As a result, the brightness of an anode using a phosphor that has been treated with high-speed electron beam irradiation is 120 to
A value of 13M was obtained.

This effect is thought to be caused by the following reasons. It is believed that the light emission of this phosphor is caused by the transfer of electrons from Zn interstitial atoms to Zn vacancies. Therefore, the more interstitials there are in zn, the more the transition will occur, and the luminance will be stronger.

When electron beam irradiation is performed from above the zinc plate 3 as shown in Fig. 1,
The electron beam recoils the zinc atoms and at the same time causes a high density of electrons to
Forms hole plasma. When this electron-hole plasma recombination occurs, recombination energy is imparted to the recoil zinc atoms. Therefore, Zn interstitial atoms move actively in the zinc plate 3, and these Zn interstitial atoms are diffused into the phosphor. Therefore, it is thought that the number of ZH interstitial atoms in the phosphor increased, and the above-mentioned luminance increased.

FIG. 2 is a sectional view showing another embodiment of the present invention, and the same symbols are used for the same parts and corresponding parts as in FIG. 1.

In this example, a phosphor 2 is placed inside a quartz glass capsule 4, a zinc plate 3 is placed inside the phosphor 2, and a high-speed electron beam shown by the arrow is irradiated from above. be. In this case, the luminance of the phosphor 2 increased both above and below the zinc plate 3, and the increase in luminance was uniform everywhere on the phosphor 2.

In addition, in the above example, 5×10 at 7 M e V
'"'The case of electron beam irradiation with electrons/i was shown, but the same result was obtained with electron beam irradiation of l~IOM@V.Furthermore, the phosphor was also ZnO:Zn and other , ZnS:Af+C1z (ZnCd)S:At
, Ct.

In the case of Zn compound phosphors such as zn S : A u *AZ, the appearance of a relationship was confirmed. The zinc plate 3 is not limited to a plate, and the same effect can be obtained by irradiating a high-speed electron beam onto a mixture in which a sufficient amount of metallic zinc, which is sufficiently larger than the particles of the phosphor, is mixed in the phosphor 2. The results were obtained. Preferably, the mixing ratio of metallic zinc and phosphor powder is 1:1 or more.

As explained above, the phosphor treatment method according to the present invention includes:
Since a mixture of phosphor and metallic zinc was irradiated with a high-speed electron beam, it had the excellent effect of being able to control the luminance of the phosphor compared to before irradiation with the electron beam.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a state in which a phosphor is processed using one embodiment of the phosphor processing method according to the present invention, and Fig. 2 is a diagram showing a state in which a phosphor is processed using another embodiment. FIG. 1, 4... quartz glass, 2... Φ phosphor, 3-...
Φ・Zinc plate. Patent applicant: Ise Electronics Co., Ltd. agent Masaki Yamakawa Ct or one person)

Claims (1)

[Claims] A method for treating a phosphor, which comprises bringing metal zinc into contact with the phosphor and irradiating the phosphor with a high-speed electron beam at a level that causes the zinc atoms of the metal zinc to recoil.