Claims
- 1. An optical recording medium having a substrate with grooves thereon, said grooves having a recording layer formed thereon wherein each of said grooves has substantially flat bottom to satisfy the condition IGr/Io>/ 0.85, where Io represents the reflected light quantity from the mirror surface and IGr represents the reflected light quantity from groove surface when a laser beam is concentrated to a spot size of approximately 1 micrometer on the surface of the medium, and to enable three-spot tracking to be performed, wherein each of said grooves has a shape satisfying the condition IGr>/ILa where ILa represents the reflected light quantity from a land adjacent the groove.
- 2. An optical recording medium according to claim 1, wherein said recording layer is formed of an SiN film, a vertical magnetization film Mo film, an SiN film, and an Al film deposited on the groove in succession.
- 3. An optical recording medium according to claim 1, wherein said mirror surface is formed at the portion other than data areas, flag areas, and address areas.
- 4. An optical recording medium according to claim 1, wherein the width of the groove surface is most preferably set to 1.1-1.3 .mu.m.
- 5. The optical recording medium according to claim 1, wherein said grooves constitute a spiral groove, said medium having a track pitch, and wherein the bottom of each of said grooves has a width in relation to a width of said track pitch in the ratio from 1.1/1.6 to 1.3/1.6.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-127589 |
May 1990 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 07/701,114, filed May 16, 1991, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4569881 |
Freese et al. |
Feb 1986 |
|
4931336 |
Haneda |
Jun 1990 |
|
5107486 |
Inui et al. |
Apr 1992 |
|
Foreign Referenced Citations (3)
Number |
Date |
Country |
62-164237 |
Jul 1987 |
JPX |
1-184736 |
Jul 1989 |
JPX |
2-161632 |
Jun 1990 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
701114 |
May 1991 |
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