摘要:
A magnetic disc apparatus includes a magnetic disc for recording information; a thin film magnetic head including a magnetic pole structure having an upper magnetic pole tip and a lower magnetic pole tip arranged to provide a magnetic gap at respective end portions thereof for writing and reading information in and from the magnetic disc; a device for rotating the magnetic disc; and a device for positioning the thin film magnetic head; the upper and lower magnetic pole tips having different contours at the respective end portions as viewed from a side confronting the magnetic disc wherein the difference (.DELTA.CW in .mu.m) in the width, along the magnetic gap, of the upper magnetic pole tip and the width, along the magnetic gap, of the lower magnetic pole tip satisfies the relation0
摘要:
A magnetic disc apparatus has a large recording density of 120 megabits per square inch or more, and defines a relationship among a pole thickness (Pt) of thin-film magnetic heads disposed in the magnetic disc apparatus, and a saturation flux density (Bs) of cores of the heads and a recording wavelength (.lambda.) for the thin film magnetic discs have a coercivity of 1800 Oe or more, wherein a levitation space between the head and the disc is 0.15 .mu.m or less.
摘要:
A magnetic disc unit has a thin film magnetic head in which a lower magnetic core and an upper magnetic core form a magnetic circuit. The upper magnetic core is constructed by magnetic films having at least two layers. A saturation magnetic flux density of the inside magnetic film, of the magnetic films having at least two layers, facing a magnetic gap of the magnetic circuit is larger than that of the outside magnetic films of the upper magnetic core and the lower magnetic core.
摘要:
A leaking magnetic flux from a taper portion is canceled by utilizing an eddy current loss by using a magnetic head having a structure wherein at least a part of a magnetic pole constituting a magnetic path through a recording gap is sandwiched by conductive materials with respect to a track width direction, and a write blur quantity can be thus reduced. Further, magnetic saturation can be prevented by limiting a volume decrease at the distal end portion of the magnetic pole when the track width is reduced. Accordingly, the present invention can prevent magnetic saturation of the distal end portion of the magnetic pole resulting from the reduction of the width of the track of the recording head, can accomplish narrow-track recording by the recording head to a recording medium having high-coercive force and can reduce write blur. Further, the present invention can provide a narrow-track magnetic head capable of accomplishing a high-speed transfer, large-capacity magnetic recording system, and a magnetic memory apparatus using this magnetic head.
摘要:
A mobile communication system, which is capable of improving a hand-off success rate of a mobile terminal moving in a high speed, and also capable of improving a process capability of a base station during hand-off control operation, is realized. When the mobile terminal, which has moved from one cell to another cell during communication, receives a hand-off instruction signal from a hand-off control unit of a mobile switching center, an electric field level measurement stopping unit stops the electric field level measurement of the forward control channels of the adjoining base stations which has instructed from the original hand-off base station, and also stops the transmission of the electric field level measurement result signal.
摘要:
A cavity surface-forming plate of a mold for injection-molding a plastic substrate is coarsely polished, and then a surface for defining a cavity is applied with electroless Ni-P plating. The surface of the plating is polished with abrasive grains to obtain surface roughness of Ra.ltoreq.2.0 nm and Rmax.ltoreq.22 nm. The plastic substrate molded with the mold has smoothness equivalent to the polished plating surface. A concave-convex pattern for forming pits may be formed on the cavity surface. A magnetic disk or an optical disk provided with the substrate makes it possible to realize the near contact system for a magnetic or magneto-optical head. Thus, it is possible to realize high density recording.
摘要:
A magnetic storage apparatus includes a magnetic head having sliding front and rear pads on its sliding surface. The front pads are tapered toward their front ends and the height of the front pads are higher than the height of the rear pad. The tapered front pads are coated with a thin film. The magnetic pad is provided with a total of three pads, two pads on its front side and one pad on its rear side. The sum area of the pads is within a range of 0.0003 to 0.02 mm.sup.2. A recording and reproducing operation is performed with the front pads and the rear pad concurrently kept in contact sliding with the surface of a recording medium. A reliable contact sliding is thus performed with the pads kept in contact with the recording medium. The magnetic head reliably operates with its recording and reproducing component kept in close vicinity with the recording medium. Therefore, a reliable magnetic head and a magnetic storage apparatus employing it are provided.
摘要:
An analog data acquisition device fetches a plurality of analog data by a multiplexer in time-division, compares the analog data fetched with a reference value applied from a digital-to-analog converter by a two-input comparator, and produces the result of comparison to a data bus. The result of comparison is also applied to a successive approximation register where the analong-to-digital conversion is effected by successively changing the digital data to the digital-to-analog converter, and the digital data converted is read out onto the data bus.The digital data applied to the digital-to-analog converter is either the output from the successive approximation register or the output from the reference register loaded through the data bus, in accordance with the contents of the control register loaded through the data bus. Thus, in which mode the device operates, in the comparing mode or in the analog-to-digital conversion mode, is selected by the control register.
摘要:
An optical element being high in productivity and capable of ensuring a large bonding area, and a production method of the optical element. At mold opening when a top part (120) provided with a round portion (121) moves upward, a preform is placed in an inner space the interior of which is formed by a rectangular sleeve (110) and the round portion (131) of a bottom part (130). At mold clamping when the top part (120) moves downward, the preform is pressurized. That is, a convex lens portion is transferred by the concave curved surface (122) and the edge surface (123) of the round portion (121) and the concave curved surface (132) and the edge surface (133) of the round portion (131). The four side surfaces of an optical element (1) are transferred by the inner wall surface (110a) of the sleeve (110). Further, part of the preform jumps out into the gap portion (140) between the outer peripheral surfaces (121a, 131a) of the round portions (121, 131) and the inner wall surface (110a) of the sleeve (110) to thereby form a protrusion portion of the optical element (1). The optical element (1) has a marker (2) formed on the top surface (11a) of its body, and the marker (2) may be formed to extend linearly along the optical axis of lens portions (12, 16). The marker (2) is formed to protrude from the top surface (11a). The side surface (11b) and the side surface (11c) of the body may be formed such that the separating distance between the side surface (11b) and the side surface (11c) gradually increases toward a bottom surface (11d).
摘要:
A cavity surface-forming plate of a mold for injection-molding a plastic substrate is coarsely polished, and then a surface for defining a cavity is applied with electroless Ni—P plating. The surface of the plating is polished with abrasive grains to obtain surface roughness of Ra≦2.0 nm and Rmax≦22 nm. The plastic substrate molded with the mold has smoothness equivalent to the polished plating surface. A concave-convex pattern for forming pits may be formed on the cavity surface. A magnetic disk or an optical disk provided with the substrate makes it possible to realize the near contact system for a magnetic or magneto-optical head. Thus, it is possible to realize high density recording.