Patent ID: 7724620

Claim:
An information recording/reproducing apparatus, comprising: a spindle motor for rotationally driving an optical disk of rewritable type, at a predetermined speed; an information recording portion for recording information, through irradiating a laser beam upon an information recording surface of said optical disk of rewritable type, which is rotationally driven by said spindle motor; an information reproducing portion for reproducing the information upon the information recording surface on said optical disk of rewritable type, through reflection light of the laser beam reflected upon the information recording surface thereof; a memory device for storing information; a controller portion for controlling operation in each of the portions mentioned above; wherein said optical disk of rewritable type comprises a data area, on which recording/reproducing of the information is conducted by a unit of block comprising a plurality of sectors, an alternation area, on which recording of information about a defective sector in a block is conducted alternately, and a management area in which management information is recorded, said management information including an address of said block having said defective sector therein and an address of an alternation area corresponding to said block, wherein the information is recorded in said alternation area, wherein said management information indicates validity or invalidity of information in said block, wherein when a first block and a second block adjacent to said first block are to be reproduced, and (1) said second block is a last correctable area in said reproducing area of said optical disk and (2) said management information in said management area indicates that said second block includes a defective sector, then said controller portion: reproduces said first block; reproduces said second block and store information resulting therefrom into said memory device; reproduces information stored in said alternation area corresponding to said second block; and reproduces a combination of information from said second block and information from said alternation area.