Single pole type recording head with tapered edges
View Patent ↗A magnetic head for perpendicular recording without writing from the lateral sides of a mains pole and without erasing data on adjacent tracks. A magnetic disk storage apparatus using the magnetic head. The lateral side of the main pole of a magnetic head for perpendicular recording may have an inverted tapered shape obtained by forming a groove as a track portion to an inorganic insulating layer and then forming a magnetic layer and then flattening the upper surface. A leading edge, a trailing edge, or both lateral edges of the magnetic head may be tapered. The taper may be either smooth and linear or curved in profile.
1. A single pole type recording head for recording on a perpendicular magnetic recording medium having a soft magnetic underlayer comprising:
a main pole including an upper, lower, and two lateral side surfaces, and further including an air bearing surface which is generally perpendicular to said upper, lower and two lateral side surfaces, said lower surface and upper surface defining a leading side and a trailing side of the main pole, respectively; and
an auxiliary pole, wherein said two side surfaces of the main pole are tapered in the direction of the flying height as viewed from the air bearing surface,
and further wherein said main pole is tapered on the leading side in the direction of the flying height as viewed from the air bearing surface.
2. A single pole type recording head according to claim 1 , wherein a magnetic circuit is established from the main pole through the magnetic underlayer and into the auxiliary magnetic pole.
3. A single pole type recording head according to claim 1 , wherein the taper of said two side surfaces occurs in two stages, wherein in an upper taper portion (away from said air bearing surface), the two side surfaces are tapered a first amount, and in a lower taper portion (between said upper taper portion and said air bearing surface, the two side surfaces are tapered substantially more than said first amount.
4. A writing/reading head comprising:
a reading head; and
a single pole type writing head for recording on a perpendicular magnetic recording medium having a soft magnetic underlayer comprising
a main pole including an upper, lower, and two lateral side surfaces, and further including an air bearing surface which is generally perpendicular to said upper, lower and two lateral side surfaces, said lower surface and upper surface defining a leading side and a trailing side of the main pole, respectively, and
an auxiliary pole, wherein said two side surfaces of the main pole are tapered in the direction of the flying height as viewed from the air bearing surface, and further wherein said main pole has a tapered surface on the-leading side in the direction of the flying height as viewed from an air bearing surface, further wherein the tapered surface intersects the air bearing surface.
5. A writing/reading head according to claim 4 , wherein the angle formed between the air bearing surface of the main pole and the tapered surface is no more than 75°.
6. A writing/reading head according to claim 5 , wherein said angle is in the range of 45° to 75°.
7. A writing/reading head according to claim 4 , wherein the tapered surface is provided both on the leading side and on the trailing side of the main pole.
8. A writing/reading head according to claim 4 , wherein a magnetic circuit is established from the main pole through the magnetic underlayer and into the auxiliary magnetic pole.
9. A writing/reading head according to claim 4 , wherein the taper of said two side surfaces occurs in two stages, wherein in an upper taper portion (away from said air bearing surface), the two side surfaces are tapered a first amount, and
in a lower taper portion (between said upper taper portion and said air bearing surface, the two side surfaces are tapered substantially more than said first amount.
10. A writing/reading head, comprising:
a reading head; and
a single pole type recording head comprising a main pole and an auxiliary pole, wherein the main pole has a tapered surface on the leading side in the direction of the flying height as viewed from an air bearing surface, and wherein the tapered surface intersecting the air bearing surface, and the angle θ defined as θ=ArcTan(h/W) is between 45° and 75°, wherein h represents a projected length of a segment formed with the tapered surface in the direction of the flying height relative to the cross section and W represents a projected length of the segment to the air bearing surface of the main pole as viewed from the direction of the track.
11. A magnetic disk storage apparatus, comprising:
a single pole type recording head for recording on a perpendicular magnetic recording medium having a soft magnetic underlayer having
an auxiliary pole, and
a main pole including an upper, lower, and two lateral side surfaces, and further including an air bearing surface which is generally perpendicular to said upper, lower and two lateral side surfaces, said lower surface and upper surface defining a leading side and a trailing side of the main pole, respectively, wherein said two side surfaces of the main pole are tapered in the direction of the flying height as viewed from the air bearing surface, and further wherein said main pole is tapered in the direction of the flying height on the leading side as viewed from the air bearing surface; and
a perpendicular magnetic recording medium having a soft magnetic underlayer, wherein a magnetic circuit is established from the main pole through the magnetic underlayer and into the auxiliary magnetic pole.
12. A magnetic disk storage apparatus according to claim 11 , wherein the angle formed between the air bearing surface and the tapered surface of the main pole is in the range the range of approximately 45° to 75°.