Patent ID: 7821897

Claim:
An information recording/reproducing apparatus, comprising: a spindle motor which rotationally drives an optical disk of rewritable type at a predetermined speed; an information recording portion which records information thereon, through irradiating a laser beam upon an information recording surface of said rewritable type optical disk, which is rotationally driven by said spindle motor; an information reproducing portion which reproduces information recorded thereon, through detecting a reflection laser light upon the information recording surface of said rewritable type optical disk; and a controller portion which conducts a read modify write operation upon said rewritable type optical disk, the controller configured to: determine whether a range of a write command is consistent or not, with a unit of cluster of said rewritable type optical disk, when said write command onto said rewritable type optical disk needs no verify process thereon, execute said read modify write operation irrespectively of content of recorded information when said range of the write command is not consistent with the unit of cluster, and conduct the verify process only on a first cluster and a last cluster among a plurality clusters that are written through said read modify write operation.