Image display and method for evaluating glass substrate to be used in same
View Patent ↗Provided are an image display device capable of displaying a good image by suppressing yellowing of a glass substrate, and an evaluating method of the glass substrate. The image display device is formed using the glass substrate where reflectance at wavelength of 220 nm is 5% or lower. In the evaluating method of the glass substrate for the image display device, Sn ++ content in the glass substrate is analyzed using reflectance at wavelength of 220 nm.
1. An evaluating method of a front-side glass substrate manufactured by a float method for an image display device, the evaluating method comprising:
measuring reflection spectrum at a wavelength of 180 to 280 nm;
dividing the measured reflection spectrum into two components by a curve fitting method using a following equation (2)
M
1
exp
{
-
(
1240
/
λ
-
1240
/
M
2
)
2
M
3
2
}
+
M
4
exp
{
-
(
1240
/
λ
-
1240
/
M
5
)
2
M
6
2
}
(
2
)
one of the components being a component with Gaussian peak at a wavelength of 220 nm and a correlation to Sn ++ , and the other of the components being a component with no correlation to Sn ++ ;
comparing areas of the components with Gaussian peak at a wavelength of 220 nm having a correlation to Sn ++ ; and
analyzing Sn ++ content in the front-side glass substrate,
wherein λ is a wavelength (nm), and M 1 to M 6 are fitting parameters.