33results about How to "Shorten the length of the magnetic circuit" patented technology

A thin-film magnetic head comprises a medium facing surface, a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The bottom pole layer and the top pole layer are coupled to each other via a coupling portion located away from the medium facing surface. The coupling portion has an end face facing toward the medium facing surface. The end face includes a curved surface convex toward the medium facing surface. The thin-film coil has a conductive layer of three turns disposed around the coupling portion. The first turn of the conductive layer from an inner side thereof includes a portion disposed between the end face of the coupling portion and the medium facing surface. This portion has a minimum width of the conductive layer at a position on a virtual line connecting the end face of the coupling portion and the medium facing surface in the shortest distance, and increases in width with distance from the virtual line.

A magnetic head includes first and second coils, a main pole, a first shield, and first and second return path sections. The first shield and the first return path section are located forward of the main pole in the direction of travel of the recording medium. The first return path section connects the main pole and the first shield so that a first space is defined. The second return path section is located backward of the main pole in the direction of travel of the recording medium so that a second space is defined. The first coil includes at least one first coil element passing through the first space. The second coil includes a plurality of second coil elements passing through the second space. The at least one first coil element is smaller in number than the second coil elements.

A thin-film magnetic head comprises a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The thin-film magnetic head further comprises a coupling portion which is located away from an air bearing surface and establishes coupling between the bottom pole layer and the top pole layer. The coupling portion has an end face facing toward the air bearing surface. The end face includes a curved surface convex toward the medium facing surface. A part of the thin-film coil, which is disposed between the end face and the air bearing surface, has a minimum width of the thin-film coil in a position on a virtual line connecting the end face and the air bearing surface in the shortest distance, and increases in width with distance from the virtual line.

The challenge to be solved by the present invention is the miniaturization of a 1-300 W class of motor. This can be achieved by using a hollow-cylinder shaped anisotropic bonded magnet magnetized in a 4-pole configuration. The anisotropic bonded magnet has a maximum energy product approximately 4 times greater than the conventional sintered ferrite magnets. The use of a 4-pole configuration shortens the magnetic path length of the individual magnetic circuits and the magnetic force contributing to the torque is increased. When the torque is kept the same as in the conventional motor, the length of the electromagnetic rotor core and the axial magnet length can be reduced. In this fashion, 1-300 W class motors can be reduced in size.

A magnetic head includes: a main pole; a coil; a first shield with an end face located in a medium facing surface at a position forward of an end face of the main pole along a direction of travel of a recording medium; a gap part including a portion located between the main pole and the first shield; and a first return path section disposed forward of the main pole along the direction of travel of the recording medium. The first return path section connects the first shield and the main pole to each other so that a first space is defined by the main pole, the gap part, the first shield, and the first return path section. The coil includes a plurality of first coil elements extending to pass through the first space and aligned in a row in the direction of travel of the recording medium.

A magnetic head includes: a main pole; a coil; a first shield having an end face that is located in a medium facing surface at a position forward of an end face of the main pole along a direction of travel of a recording medium; and a first return path section disposed forward of the main pole along the direction of travel of the recording medium. The first return path section connects part of the main pole away from the medium facing surface to the first shield so that a first space is defined. The coil includes a first portion having a planar spiral shape and wound around a core part of the first return path section. The first portion includes first and second coil elements that each extend through the first space. No part of the coil other than the first and second coil elements exists in the first space.

A thin-film magnetic head includes an insulation gap, first and second yoke layers with first and second ends, respectively, the first ends constituting magnetic poles separated from each other by the insulation gap, the second ends being magnetically coupled with each other, and a coil conductor constituted by a plurality of single layer turns, for generating magnetic field and applying the generated magnetic field into the first and second yoke layers. Each turn of the coil conductor includes a first section, a second section with one end coupled with one end of the first section, and a third section with one end coupled with the other end of the second section. The third section travels to pass outside of the first yoke layer in parallel with the surface of the first yoke layer, and to extend over the first yoke layer.

A thin-film magnetic head comprises a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The thin-film coil is wound in a helical manner around the top pole layer while the coil is insulated from the bottom pole layer and the top pole layer. The thin-film coil includes a plurality of inner conductor portions, a plurality of outer conductor portions, and a plurality of connecting portions that connect the inner conductor portions to the outer conductor portions. The inner conductor portions are disposed between the bottom pole layer and the top pole layer. The outer conductor portions are disposed on a side opposite to the inner conductor portions, the top pole layer being disposed in between. A thin insulating film is only provided between adjacent ones of the inner conductor portions.

A magnetic head includes first to third coils, a main pole, a write shield, first and second yoke layers, and first and second coupling parts. The first and second yoke layers are magnetically connected to the write shield. The first yoke layer is located on the leading side relative to the main pole, whereas the second yoke layer is located on the trailing side relative to the main pole. The first coupling part magnetically couples the main pole and the second yoke layer to each other. The second coupling part magnetically couples the first yoke layer and the second yoke layer to each other. The first coil is wound around the first coupling part, whereas the second and third coils are wound around the second coupling part.

On a surface of a bottom pole, a write gap film and first magnetic material film having a high saturation magnetic flux density are formed, and the first magnetic material film is etched to remain a portion extending from an air bearing surface to a throat height zero reference position and a first non-magnetic film is formed in a removed portion. The first non-magnetic material film is polished to obtain a flat surface which is coplanar with a surface of the first magnetic material film. A second magnetic material film having a high saturation magnetic flux density is formed on the flat surface. The second magnetic material film, first magnetic material film, write gap film and bottom pole are partially removed by RIE using a mask formed on the flat surface.

A thin-film magnetic head includes a bottom pole layer, a top pole layer, a recording gap layer, and a thin-film coil. The bottom pole layer has first to fifth layers. The third layer and the fifth layer constitute a coupling portion for establishing magnetic coupling between the bottom pole layer and the top pole layer. The thin-film coil has first to fifth layer portions each of which is made of a flat conductive layer of a single turn. The first to fifth layer portions are laminated, and connected in series to each other. The coupling portion has an end face facing toward the air bearing surface. The end face includes a curved surface convex toward the medium facing surface.