Oxide phosphorescent glass capable of exhibiting a long...

Details Oxide phosphorescent glass capable of exhibiting a long... Oxide phosphorescent glass capable of exhibiting a long...

1999-05-12

2001-08-07

Sample, David R (Department: 1755)

Compositions: ceramic

Ceramic compositions

Glass compositions, compositions containing glass other than...

C501S049000, C501S050000, C501S052000, C501S064000, C501S065000, C501S066000, C501S067000, C501S069000, C501S072000, C501S073000, C501S078000, C501S079000, C252S30160F, C252S30160R, C252S30140F

Reexamination Certificate

active

06271160

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an oxide glass capable of exhibiting a long lasting afterglow and photostimulated luminescence, whereby energy can be accumulated by radiation excitation, for example, by &ggr;-rays, X-rays, UV-rays, etc., light emission can be continued for a long time even after stopping the excitation, so that the oxide glass can be used as a phosphorescent material for night illumination or night signal, and furthermore, photostimulated luminescence can be exhibited by irradiation of visible rays or infrared rays, which is useful for confirming an infrared laser or controlling an optical axis of a laser beam, so that recording or reproducing of &ggr;-rays, X-rays or UV-rays images can be effected, and which can be used as an optical recording material capable of reading and writing.
2. Description of the Prior Art
Phosphorescent materials or photostimulated luminescence phosphor using rare earth elements have widely been used up to the present time. As a phosphorescent material, there can practically be used SrAl
2
O
4
:Eu
2+
, Dy
3+
, etc. and as a photostimulated luminescence phosphor, there has already been developed BaFBr:Eu
2+
, etc. These are opaque materials only exhibiting superficial phosphorescence, generally obtained by coating a suitable carrier with a powdered phosphorescent material or photostimulated luminescence phosphor.
On the other hand, a glass capable of exhibiting a photostimulated luminescence without coating a photostimulated luminescence phosphor has been disclosed in Japanese Patent Laid-Open Publication No. 221336/1997. In addition, Japanese Patent Application Nos. 346362/1997 and 88674/1998 respectively disclose obtaining phosphorescent glasses of SiO
2
—B
2
O
3
—ZnO—Tb
2
O
3
system and SiO
2
—Ga
2
O
3
—Na
2
O—Tb
2
O
3
system.
In the case of coating a powdered phosphorescent material or photostimulated luminescent phosphor, dispersion of the coating thickness or peeling-off of the coated surface occurs whereby to cause light and shade of the phosphorescence. In order to increase the emission intensity, it is required to coat a phosphorescent material or photostimulated luminescence phosphor with a larger thickness, but the coating is limited by increase of opaqueness thereof. Since a phosphorescence emitted from a grain boundary in the phosphorescent material or photostimulated luminescence phosphor is scattered, furthermore, no clear image can be obtained.
A photostimulated luminescent glass described in Japanese Patent Laid-Open Publication No. 221336/1997 utilizes Ce
3+
or Eu
2+
as an active ion for emission. In order to obtain these active ions, it is necessary to add a reducing agent or to melt in a reducing atmosphere. Furthermore, observation of the emission is difficult because of being UV light or blue light.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a Tb- or Mn-containing oxide phosphorescent glass whereby the above described problems of the prior art can be solved.
It is another object of the present invention to provide an oxide glass capable of exhibiting a long lasting afterglow and photostimulated luminescence of green or red emitted light readily observable, which can be melted without using any reducing agent or reducing atmosphere by utilizing Tb or Mn as a phosphorescent or luminescent agent.
These objects can be attained by an oxide glass capable of exhibiting a long lasting afterglow and photostimulated luminescence by excitation with radiations such as &ggr;-rays, X-rays or UV-rays, having a constitutional composition comprising, at least, 21 to 80 mol % of germanium oxide (GeO
2
) and the balance of zinc oxide (ZnO) or gallium oxide (Ga
2
O
3
), alkali metal oxide or alkaline earth metal oxide and terbium oxide (Tb
2
O
3
) or manganese oxide (MnO).


REFERENCES:
patent: 3714059 (1973-01-01), Shaw et al.
patent: 4999321 (1991-03-01), Kohli
patent: 5786287 (1998-07-01), Bayya et al.
patent: 5955388 (1999-09-01), Dejneka
patent: 779 254 (1997-06-01), None
patent: 0 926 102 (1999-06-01), None
patent: 422697 (1974-04-01), None
patent: 98/58884 (1998-12-01), None
Ageeva L et al.: “The Spectral-Luminescence Parameters of Neodymium-Activated Alkali Germanate Glasses with a High Concentration of GEO2” Soviet Journal of Glass Physics and Chemistry, vol. 16, No. 1, Jan. 1, 1990, pp. 15-20, XP00169372 ISSN: 0360-5043.
Database Inspec 'Online,!Institute of Electrical Engineers, Stevenage, GB, Hirayama C et al.: “Fluorescence of Fe, Co, and Ni in reduced germanate glass” Electrochemical Society, Dec. 1968, 1968, USA, vol. 115, No. 12, pp. 1275-1279, XP002115735 ISSN: 0013-4651.
Database WPI Section Ch, Week 8846 Derwent Publications Ltd., London, GB; Class L01, AN 88-328789 XP002115739 & SU 1 393 811 A (Karapetyan G O), May 7, 1988 *abstract*.
Database Inspec 'Online! Institute of Electrical Engineers, Stevenage, GB Van Die A et al.: “Germanate glasses as hosts for luminescence of MN/sup 2+/ and Cr/sup3+/” Database accession No. 3134632 XP002115736 *abstract* -& Journal of Non-Crystalline Solids, Jan. 1988, Netherlands, vol. 99, No. 1, pp. 32-44, XP002115733 ISSN: 0022-3093.
Database Inspec 'Online! Institute of Electrical Engineers, Stevenage, GB Grishchuk E V et al.: “Some features of the concentration quenching of the luminescence of Tb/sup3+/(/sup 5/D/sub3/) in sodium germanate glass” Database accession No. 3449637 XP002115737 *abstract* -& Fizika I Khimiya Stekla, Nov.-Dec. 1987, USSR, vol. 13, No. 6, pp. 874-879, XP00215734 ISSN: 0132-6651.

Affiliated with

Also associated with

Rating

Oxide phosphorescent glass capable of exhibiting a long... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Oxide phosphorescent glass capable of exhibiting a long..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oxide phosphorescent glass capable of exhibiting a long... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2483028