1. An optical recording system including a recordingreproducing optical head having an objective lens and an optical radiation source for emitting light having a wavelength of between 300 nm and 500 nm, and an optical recording medium recorded and reproduced with irradiation of light thereon from said optical head, said irradiation of light being made by the objective lens of which numerical aperture is larger than 1 when irradiated with a light wavelength of substantially 400 nm, said optical recording medium comprising at least a silicon oxide layer and a silicon layer being formed over a substrate in that order,
wherein said silicon layer has formed thereon a protective layer of which refractive index is larger than a numerical aperture of said objective lens, and
wherein said objective lens is comprised of a system of two lenses, at least one of which is a solid immersion lens (SIL) and said solid immersion lens is shaped like a conical surface;
wherein said silicon oxide layer is formed directly on said substrate, said silicon layer is formed directly on said silicon oxide layer, and said protective layer is formed directly on said silicon layer, and
wherein both said silicon layer and said protective layer have a refractive index larger than a numerical aperture of said objective lens when irradiated with a light wavelength of substantially 400 nm.
2. The optical recording system according to claim 1, wherein said recorded pits are recorded by changing said silicon layer into silicon oxide.
3. An optical recording and reproducing method for recording and reproducing data from an optical recording medium with irradiation of light having a wavelength of between 300 nm and 500 nm from an objective lens contained in an optical recordingreproducing head, said light being irradiated through the objective lens having a numerical aperture larger than 1 when irradiated with a light wavelength of substantially 400 nm, wherein said optical recording medium has at least a silicon oxide layer, a silicon layer, and a protective layer formed over a substrate, in that order, recorded pits being formed by changing said silicon layer into silicon oxide, and
a refractive index of the protective layer is larger than a numerical aperture of said objective lens, and
wherein said objective lens is comprised of a system of two lenses, at least one of which is a solid immersion lens (SIL) and said solid immersion lens is shared like a conical surface;
wherein said silicon oxide layer is formed directly on said substrate, said silicon layer is formed directly on said silicon oxide layer, and said protective layer is formed directly on said silicon layer, and
wherein both said silicon layer and said protective layer have a refractive index larger than a numerical aperture of said objective lens when irradiated with a light wavelength of substantially 400 nm.
4. The optical recording system according to claim 1, wherein both said silicon layer and said protective layer have a refractive index larger than a numerical aperture of said objective lens when irradiated with a light wavelength of substantially 400 nm.
5. The optical recording and reproducing method according to claim 3, wherein both said silicon layer and said protective layer have a refractive index larger than a numerical aperture of said objective lens when irradiated with a light wavelength of substantially 400 nm.
6. The optical recording system according to claim 1, wherein the refractive index of the silicon recording layer is greater than 4 when irradiated by said light.
7. The optical recording and reproducing method according to claim 3, wherein the refractive index of the silicon recording layer is greater than 4 when irradiated by said light.
8. The optical recording system according to claim 1, wherein said solid immersion lens (SIL) has a main component material selected from the group consisting of SrTiO3, Bi4Ge2O12, and Bi4Ge3O12.
9. The optical recording and reproducing method according to claim 3, wherein said solid immersion lens (SIL) has a main component material selected from the group consisting of SrTiO3, Bi4Ge2O12, and Bi4Ge3O12.
10. The optical recording system according to claim 1, wherein the composition of the SIL lens is selected so as to cause the objective lens to have an overall numerical aperture larger than 1 when irradiated with a light wavelength of substantially 400 nm.
11. The optical recording system according to claim 1, wherein the silicon oxide layer has a refractive index less than 1.5 when irradiated with a light wavelength of substantially 400 nm.
12. The optical recording system according to claim 1, wherein every layer of the optical recording medium is comprised of a silicon compound.
13. The optical recording system according to claim 1, wherein the optical recording medium contains only layer compositions that are not harmful for the natural environment and have small load to the natural environment.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of reducing data corruption due to recycled Internet Protocol (IP) identification numbers comprising the steps of:
determining whether packets are to be divided into fragments;
determining, if packets are to be divided into fragments, whether IP identification numbers are being recycled; and
setting a size of a first fragment of a packet to a maximum transmission unit (MTU), if the IP identification numbers are recycling and decrementing the size of the first fragment of a packet each time the IP identification numbers recycle.
2. The method of claim 1 wherein the size of the first fragment of a packet is decremented until it is equal to a predefined minimum transmission unit.
3. The method of claim 2 wherein each time the size of the first fragment of a packet is to be decremented, it is decremented by one octet.
4. The method of claim 3 wherein after being equal to the minimum transmission unit, the size of the first fragment is set to MTU the next time the IP identification numbers recycle.
5. The method of claim 4 wherein when the first fragment of a packet is decremented, the fragment offset of all other fragments of the packet is modified.
6. The method of claim 5 wherein if the IP identification number of all fragments is the same and the fragment offset of a fragment is not consistent with each other, the packet is discarded.
7. The method of claim 6 wherein if the IP identification number of all fragments is the same and the fragment offset of a fragment is consistent with each other, the fragments are used to re-assemble the packet.
8. The method of claim 7 wherein the packet is discarded or re-assembled by a receiving host.
9. A computer program product on a computer readable medium for reducing data corruption due to recycled Internet Protocol (IP) identification numbers comprising:
code means for determining whether packets are to be divided into fragments;
code means for determining, if packets are to be divided into fragments, whether IP identification numbers are being recycled; and
code means for setting a size of a first fragment of a packet to a maximum transmission unit (MTU) if the IP identification numbers are recycling and decrementing the size of the first fragment of a packet each time the IP identification numbers recycle.
10. The computer program product of claim 9 wherein the size of the first fragment of a packet is decremented until it is equal to a predefined minimum transmission unit.
11. The computer program product of claim 10 wherein each time the size of the first fragment of a packet is to be decremented, it is decremented by one octet.
12. The computer program product of claim 11 wherein after being equal to the minimum transmission unit, the size of the first fragment is set to MTU the next time the IP identification numbers recycle.
13. The computer program product of claim 12 wherein when the first fragment of a packet is decremented, the fragment offset of all other fragments of the packet is modified.
14. The computer program product of claim 13 wherein if the IP identification number of all fragments is the same and the fragment offset of a fragment is not consistent with each other, the packet is discarded.
15. The computer program product of claim 14 wherein if the IP identification number of all fragments is the same and the fragment offset of a fragment is consistent with each other, the fragments are used to re-assemble the packet.
16. The computer program product of claim 15 wherein the packet is discarded or re-assembled by a receiving host.
17. A system for reducing data corruption due to recycled Internet Protocol (IP) identification numbers comprising:
at least one storage system for storing code data; and
at least one processor for processing the code data to determine whether packets are to be divided into fragments, to determine, if packets are to be divided into fragments, whether IP identification numbers are being recycled, and to set a size of a first fragment of a packet to a maximum transmission unit (MTU) if the IP identification numbers are recycling and decrementing the size of the first fragment of a packet each time the IP identification numbers recycle.
18. The system of claim 17 wherein the size of the first fragment of a packet is decremented until it is equal to a predefined minimum transmission unit.
19. The system of claim 18 wherein each time the size of the first fragment of a packet is to be decremented, it is decremented by one octet.
20. The system of claim 19 wherein after being equal to the minimum transmission unit, the size of the first fragment is set to MTU the next time the IP identification numbers recycle.