Optical information recording medium
First Claim
1. An optical information recording medium, comprising an active layer which undergoes a base change upon irradiation with light;
- and protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light, wherein the thermal capacity Ma of the active layer and the thermal capacity Md1 of the protective layer on the side to be irradiated with light have the following relationship;
Ma≦
Md1 /3, and said active layer has a characteristic such that its minimum cyrstallization time is 90 ns or less.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed is an optical information recording medium which comprises an active layer which undergoes phase change upon irradiation with light and protective layers formed on both the sides of the active layer, wherein the thermal capacity of the active layer which is a heat source is decreased, a reflection layer of high thermal conductivity is provided on the protective layer to cause increase of the coefficient of lines expansion of the protective layer with increase in distance from the active layer or the thickness of each layer is specified to make nearly the constant maximum temperature by irradiated light against a change in the thickness of the active layer.
-
Citations
14 Claims
-
1. An optical information recording medium, comprising an active layer which undergoes a base change upon irradiation with light;
- and protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light, wherein the thermal capacity Ma of the active layer and the thermal capacity Md1 of the protective layer on the side to be irradiated with light have the following relationship;
Ma≦
Md1 /3, and said active layer has a characteristic such that its minimum cyrstallization time is 90 ns or less. - View Dependent Claims (2)
- and protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light, wherein the thermal capacity Ma of the active layer and the thermal capacity Md1 of the protective layer on the side to be irradiated with light have the following relationship;
-
3. An optical information recording medium, comprising an active layer which undergoes a phase change upon irradiation with light;
- protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light; and
a reflection layer which is formed on the one of said protective layers located on the side of the active layer opposite the side to be irradiated with light and which reflects back the light to the active layer, said active layer having a characteristics such that its minimum crystallization time is 90 ns or less, said one of said protective layers disposed on the side of the active layer opposite the side to be irradiated with light having a thickness of 100 nm or less, said reflection layer having a thickness of 80 nm or more, and said reflection layer having a thermal conductivity of 100 W/m·
k or more. - View Dependent Claims (4, 5)
- protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light; and
-
6. An optical information recording medium, comprising an active layer which undergoes a phase change upon irradiation with light;
- and protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light, wherein at least the one of the protective layers disposed on the side of said active layer to be irradiated with light is of a bi-layer structure and a coefficient of linear expansion of a layer of the bi-layer positioned adjacent the active layer is smaller than that of another layer of the bi-layer structure, and said active layer has a characteristic such that its minimum crystallization time is 90 ns or less.
- View Dependent Claims (7, 8)
-
9. An optical information recording medium, comprising an active layer which undergoes a phase change upon irradiation with light;
- and protective layers which are formed on both sides of the active layers, which have a higher melting point than that of the active layer and show no absorption at the wavelength of the irradiated light, wherein said active layer has a characteristic such that its minimum crystallization time is 90 ns or less and at least the one of said protective layers which is formed on the side of said active layer to be irradiated with light has a coefficient of linear expansion which varies such that it is lowest closest to the active layer and continuously increases with increase in distance from the active layer.
- View Dependent Claims (10)
-
11. An optical information recording medium, comprising an active layer which undergoes a phase change upon irradiation with light;
- protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light, wherein said active layer has a characteristic such that its minimum crystallization time is 90 ns or less; and
a reflection layer which is formed on the one of said protective layers disposed on the side of said active layer opposite the side to be irradiated with light and which reflects back the light to the active layer, the thickness of the other one of said protective layers disposed on the side of said active layer to be irradiated with light being 20λ
/64nd1 to 27λ
/64nd1 and the thickness of said one of said protective layers disposed on the side of said active layer opposite to the side to be irradiated with light being λ
/64nd2 to 5λ
/64nd2, wherein λ
represents the wavelength of the irradiated light, nd1 represents the refractive index of said other one of said protective layers and nd2 represents the refractive index of said one of said protective layers. - View Dependent Claims (12, 13, 14)
- protective layers which are formed on both sides of the active layer, which have a higher melting point than that of the active layer and which show no absorption at the wavelength of the irradiated light, wherein said active layer has a characteristic such that its minimum crystallization time is 90 ns or less; and
Specification