| US 7,602,675 B2 | ||
| Optical recording method | ||
| Takashi Ohno, Tokyo (Japan) | ||
| Assigned to Mitsubishi Kagaku Media Co., Ltd., Tokyo (Japan) | ||
| Filed on Mar. 14, 2006, as Appl. No. 11/374,042. | ||
| Application 11/374042 is a continuation of application No. PCT/JP2004/015173, filed on Oct. 14, 2004. | ||
| Claims priority of application No. 2003-358054 (JP), filed on Oct. 17, 2003. | ||
| Prior Publication US 2006/0153047 A1, Jul. 13, 2006 | ||
| Int. Cl. G11B 11/00 (2006.01) | ||
| U.S. Cl. 369—13.26 | 10 Claims |
| 1. An optical recording method configured to apply recording light locally on an optical recording medium and to record information
subjected to mark length modulation by use of recording marks having a plurality of time lengths, the method comprising the
steps of:
dividing a light irradiation time period when defining a time length of one recording mark as nT (T is a reference clock period
and n is a natural number equal to or above 2) for recording a recording mark having a time length of nT in the order of
α1T, β1T, α2T, β2T, . . . , αiT, βiT, . . . , αmT, βmT
(in which m is a natural number representing a divided pulse number, αi (1≤i≤m) is a real number greater than 0, βi (1≤i≤m-1) is a real number greater than 0, and βm is a real number equal to or above 0);
applying recording light having recording power Pwi (1≤i≤m) in time periods of the αiT (1≤i≤m);
applying recording light having bias power Pb satisfying Pb≤0.2×Pwi(1≤i≤m) in time periods of the βiT (1≤i≤m);
setting the divided pulse number m equal to or above 2 in terms of at least one recording mark out of the recording marks
having the plurality of time lengths; and
forming a plurality of recording marks each having a respective time length of nT by use of the same divided pulse number
m, wherein there is an m satisfying Pwshort>Pwlong, an average value of the recording power Pwiat the time periods of αiT (1≤i≤m) for forming a recording mark having a longest nT among the plurality of recording marks each having the respective
time lengths of nT is defined as Pwlong, and an average value of the recording power Pwiat the time periods of αiT (1≤i≤m) for forming a recording mark having a shortest nT among the plurality of recording marks each having the respective
time lengths of nT is defined as PWshort.
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