Information record apparatus and method, information record and reproduction apparatus and method, and computer program product

The information record apparatus is provided with: a record device for recording the information onto an information record medium by using laser light having controllable record power; a calibration device for obtaining a calibration value of the record power by recording calibration data to obtain the calibration value into a calibration area arranged in the information record medium to obtain the calibration value; and a first erase device for erasing a part of the calibration data recorded into the calibration area. Normal recording while erasing information in the calibration area is provided, which reduces buffer overflow problems.