Information recording and playback device

An information recording and playback device which records or plays back data in or from an optical disk, the device comprising:

• a recording and playback unit which includes a pickup performing irradiation with laser light, irradiates the optical disk with the laser light and records or plays back information;
• and
• a controller which controls the recording and playback unit, wherein
• the controller divides a recording area of the optical disk into a first recording area which is at an inner circumference side based on, as a boundary, a predetermined radius in a radius direction of the optical disk, and a second recording area which is at an outer circumference side, and manages the recording area,
• the predetermined radius is set to an edge of an area in which a control residual falls within a predetermined reference value or less when servo control related to focusing and tracking is performed on the recording area of the optical disk, and
• when recording or playing back data from a target position in the second recording area, the controller
• causes the pickup to make traverse movement to an innermost circumference position of the second recording area,
• causes the pickup to move while performing the servo control on the pickup after the traverse movement, and stores the control residual of the servo control in a memory, and
• when the pickup reaches the target position, performs the servo control by using the control residual stored in the memory, and starts recording or playing back the data from the target position.

An information recording and playback device which records or plays back data in or from an optical disk, the device comprising:

• a recording and playback unit which includes a pickup which performs irradiation with laser light, irradiates the optical disk with the laser light and records or plays back information;
• and
• a controller which controls the recording and playback unit, wherein
• the controller divides a recording area of the optical disk into a first recording area which is at an inner circumference side based on, as a boundary, a predetermined radius in a radius direction of the optical disk, and a second recording area which is at an outer circumference side, and manages the recording area,
• the predetermined radius is set to an edge of an area in which a control residual falls within a predetermined reference value or less when servo control related to focusing and tracking is performed on the recording area of the optical disk, and
• when recording or playing back data from a target position in the second recording area, the controller
• reduces a number of rotations of the optical disk,
• causes the pickup to make traverse movement to the target position,
• performs the servo control on the pickup while increasing the number of rotations of the optical disk in an area to which the pickup has made the traverse movement, and stores a control residual of the servo control in a memory, and
• when the number of rotations of the optical disk reaches a predetermine number of rotations, performs the servo control by using the control residual stored in the memory, and starts recording or playing back the data from the target position.