Head stack assembly and information recording apparatus

摘要

An information recording apparatus includes a medium for recording information; a head slider including a device for writing the information onto the medium and a reflective surface for reflecting light; a light emitting portion for generating emission light toward the reflective surface; a light receiving portion for detecting light reflected on the reflective surface; and a regulating mechanism for adjusting an amount of the emission light from the light emitting portion in a mode of information recording onto the medium in correspondence to a result of the detection.