1. Field of the Invention
The present invention relates to a thin-film magnetic head for applying to a magnetic recording technique in which the head writes/reads data to/from a magnetic recording medium, especially to a thin-film magnetic head for applying to perpendicular magnetic recording. The present invention further relates to a head gimbal assembly (HGA) provided with the thin-film magnetic head, and a magnetic recording and reproducing apparatus provided with the HGA.
2. Description of the Related Art
In recent years, perpendicular magnetic recording has been actively developed instead of conventional longitudinal magnetic recording to realize more improvement in a real recording density of magnetic recording and reproducing apparatuses, especially magnetic disk drive apparatuses. In the perpendicular magnetic recording, demagnetization field drastically decreases in a magnetization transition region between record bits2006-114160A describes an auxiliary magnetic pole, a lower shield or an upper shield which has a concave portion provided on the side opposite to ABS or has a recess from the head end surface on the ABS side at both end portions in the track width direction. This structure with the concave portion or the recess is intended to reduce a leakage magnetic field from the end portions of the auxiliary magnetic pole, the lower shield or the upper shield. Further, US Patent Publication 2006/0092565A1 describes a magnetic structure having a forward projecting portion extending toward ABS and the first and second side wing portions extending from the forward projecting portion along the transverse direction (the track width direction). The publication argues that even if magnetic flux concentrates