Method of reproducing information with equalization coefficient for the reproduced information

A method of reproducing information by scanning information marks, disposed with a predetermined mark pitch therebetween and recorded on tracks inside a predetermined information recording region, by an optical spot, detecting an optical change of said information marks by said scanning operation, applying signal processing to a reproducing signal obtained by said detection operation so as to reduce inter-symbol interference of an interference amount varying from one of said information marks to another of said information marks, and reproducing the information corresponding to said information mark, comprising the steps of:

• a) detecting the size of the optical change resulting from said information mark;
• b) calculating a plurality of equalization coefficients used for an equalization processing for the size of said optical change detected for each of said information marks;
• and
• c) reducing said inter-symbol interference on the basis of said equalization coefficients by said equalization processing;
• wherein said equalization coefficient used for said equalization processing of the size of said optical change by a first information mark of a first length to reduce said inter-symbol interference in said step c) is greater than said equalization coefficient used for said equalization processing of the size of said optical change by a second information mark of a second length which is greater than said first information mark.