Recording head and disk drive with the same

A recording head comprising:

• a main pole configured to apply a recording magnetic field perpendicular to a recording layer of a recording medium;
• a trailing core comprising a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole at a distance not more than double a track pitch of the recording medium;
• a first coil wound around the trailing core;
• a leading core comprising a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields, and a connecting portion joined to the main pole in a position off the recording medium, the leading core being formed mainly of a material having a saturated magnetic flux density Bs2 higher than half of a saturated magnetic flux density Bs1 of the return pole;
• and
• a second coil wound around the leading core.

A recording head comprising:

• a main pole configured to apply a recording magnetic field to a recording layer of a recording medium;
• a trailing core comprising a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole, wherein a distance between the main pole and each of the side shields is set so that the maximum intensity of a return magnetic field just below the side shield, which returns through the recording medium, is not more than an intensity of a nucleation field Hn for magnetization reversal of the recording medium;
• a first coil wound around the trailing core;
• a leading core comprising a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields with a width of 20 μm or less transversely relative to the tracks and a connecting portion joined to the main pole in a position off the recording medium;
• and
• a second coil wound around the leading core.

A recording head comprising:

• a main pole configured to apply a recording magnetic field perpendicular to a recording layer of a recording medium;
• a trailing core comprising a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole, a distance between the main pole and each of the side shields being set so that the maximum intensity of a return magnetic field just below the side shield, which returns through the recording medium, is not more than a intensity of a nucleation field Hn for magnetization reversal of the recording medium;
• a first coil wound around the trailing core;
• a leading core comprising a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields and a connecting portion joined to the main pole in a position off the recording medium, the leading core being formed mainly of a material having a saturated magnetic flux density Bs2 higher than half of a saturated magnetic flux density Bs1 of the return pole;
• and
• a second coil wound around the leading core.