Abstract: An integrated circuit for a power supply circuit configured to generate an output voltage at a target level. The power supply circuit includes a transistor configured to control an inductor current flowing through an inductor. The integrated circuit includes a load detection circuit outputting a detection voltage corresponding to a power consumption of a load and corresponding to an operation mode of the power supply circuit, based on the inductor current, a driver circuit driving the transistor according to the operation mode of the power supply circuit, and a control circuit configured to control the driver circuit to switch the power supply circuit to a second mode upon the detection voltage reaching a first level with a decrease in the power consumption of the load, and to a first mode upon the detection voltage reaching a second level with an increase in the power consumption of the load.

Abstract: An integrated circuit for a power supply circuit configured to generate an output voltage at a target level. The power supply circuit includes a transistor configured to control an inductor current flowing through an inductor. The integrated circuit includes a load detection circuit outputting a detection voltage corresponding to a power consumption of a load and corresponding to an operation mode of the power supply circuit, based on the inductor current, a driver circuit driving the transistor according to the operation mode of the power supply circuit, and a control circuit configured to control the driver circuit to switch the power supply circuit to a second mode upon the detection voltage reaching a first level with a decrease in the power consumption of the load, and to a first mode upon the detection voltage reaching a second level with an increase in the power consumption of the load.

Abstract: A magnetic recording medium with a reduced average grain diameter and reduced grain diameter dispersion is provided. A magnetic recording medium having a magnetic property (magnetic anisotropy energy) applicable as a magnetic recording medium is provided. It is a magnetic recording medium containing a substrate, a grain diameter control layer, a first seed layer, a second seed layer, and a magnetic recording layer containing an ordered alloy in this order, in which the second seed layer is composed of crystal grains having TiN as a main component, and a grain boundary material having at least one or more selected from the group consisting of metal oxides and carbon as a main component.

Abstract: An apparatus for controlling a switching power supply during burst control that includes a switching period and a no switching period. The switching power supply includes first and second switching elements and a resonance circuit. The control apparatus includes a load detecting circuit that shunts and averages a resonance current of the resonance circuit, an off signal generating circuit that generates off signals for turning off the first and second switching elements during the switching period, an on signal generating circuit that obtains a number of resonance cycles of the ringing voltage in the no switching period and generates a first pulse on signal for turning on the second switching element to restart the switching period, and a control circuit that receives the off signals and the first pulse on signal, and generates first and second control signals for alternating on-off control of the first and second switching elements.

Abstract: An apparatus for controlling a switching power supply during burst control that includes a switching period and a no switching period. The switching power supply includes first and second switching elements and a resonance circuit. The control apparatus includes a load detecting circuit that shunts and averages a resonance current of the resonance circuit, an off signal generating circuit that generates off signals for turning off the first and second switching elements during the switching period, an on signal generating circuit that obtains a number of resonance cycles of the ringing voltage in the no switching period and generates a first pulse on signal for turning on the second switching element to restart the switching period, and a control circuit that receives the off signals and the first pulse on signal, and generates first and second control signals for alternating on-off control of the first and second switching elements.

Abstract: A magnetic recording medium with a reduced average grain diameter and reduced grain diameter dispersion is provided. A magnetic recording medium having a magnetic property (magnetic anisotropy energy) applicable as a magnetic recording medium is provided. It is a magnetic recording medium containing a substrate, a grain diameter control layer, a first seed layer, a second seed layer, and a magnetic recording layer containing an ordered alloy in this order, in which the second seed layer is composed of crystal grains having TiN as a main component, and a grain boundary material having at least one or more selected from the group consisting of metal oxides and carbon as a main component.

Abstract: The present invention aims at providing a magnetic recording medium capable of realizing lowering of recording temperature. A magnetic recording medium comprises a substrate, and a magnetic recording layer comprising a first magnetic layer and a second magnetic layer, in which the second magnetic layer comprises an FePtRh ordered alloy, and the first magnetic layer has Ku at room temperature larger than Ku of the second magnetic layer at room temperature.

Abstract: The problem of the invention is to provide a process for producing a magnetic recording medium which exhibits both of excellent thermal stability and favorable writing capability. The process for producing the magnetic recording medium of the invention includes the steps of: (A) forming the first magnetic recording layer while monotonously changing a substrate temperature; and (B) forming the second magnetic recording layer while monotonously changing the substrate temperature wherein the material of the second magnetic recording layer is different from the material of the first recording layer, wherein the substrate temperature at the beginning of the step (B) is set such that the magnetic anisotropy constant of the first magnetic recording layer and the magnetic anisotropy constant of the second magnetic recording layer is changed monotonously at the interface between the first and second magnetic recording layers.

Abstract: The present invention aims at providing a magnetic recording medium capable of realizing lowering of recording temperature. A magnetic recording medium comprises a substrate, and a magnetic recording layer comprising a first magnetic layer and a second magnetic layer, in which the second magnetic layer comprises an FePtRh ordered alloy, and the first magnetic layer has Ku at room temperature larger than Ku of the second magnetic layer at room temperature.

Abstract: The problem of the invention is to provide a process for producing a magnetic recording medium which exhibits both of excellent thermal stability and favorable writing capability. The process for producing the magnetic recording medium of the invention includes the steps of: (A) forming the first magnetic recording layer while monotonously changing a substrate temperature; and (B) forming the second magnetic recording layer while monotonously changing the substrate temperature wherein the material of the second magnetic recording layer is different from the material of the first recording layer, wherein the substrate temperature at the beginning of the step (B) is set such that the magnetic anisotropy constant of the first magnetic recording layer and the magnetic anisotropy constant of the second magnetic recording layer is changed monotonously at the interface between the first and second magnetic recording layers.

Abstract: A magnetic recording medium suppresses an anticipated decline in performance due to heating of the lubricant layer and protective layer in thermally assisted recording, and has superior durability and reliability. The magnetic recording medium comprises a layer stack comprising, in order on a nonmagnetic substrate, at least a magnetic recording layer, adiabatic layer, carbon-based protective layer, and lubricant layer.

Abstract: A magnetic recording medium suppresses an anticipated decline in performance due to heating of the lubricant layer and protective layer in thermally assisted recording, and has superior durability and reliability. The magnetic recording medium comprises a layer stack comprising, in order on a nonmagnetic substrate, at least a magnetic recording layer, adiabatic layer, carbon-based protective layer, and lubricant layer.

Abstract: To measure the nonlinear distortion of a magnetic disk even at a high recording density, a nonlinear transition shift and a partial erasure are separately measured. A periodic pattern containing dibits and isolated bits, and a periodic pattern consisting only of isolated bits, are written and read in synchronism with the rotations of the magnetic disk. The reproduced waveforms of the respective periodic patterns are frequency-analyzed in a state where the phases of the periodic patterns are in agreement, thereby to obtain odd-numbered order harmonic components. The partial erasure and the nonlinear transition shift are evaluated on the basis of the ratio between the odd-numbered order harmonic components.

Abstract: To measure the nonlinear distortion of a magnetic disk even at a high recording density, a nonlinear transition shift and a partial erasure are separately measured. A periodic pattern containing dibits and isolated bits, and a periodic pattern consisting only of isolated bits, are written and read in synchronism with the rotations of the magnetic disk. The reproduced waveforms of the respective periodic patterns are frequency-analyzed in a state where the phases of the periodic patterns are in agreement, thereby to obtain odd-numbered order harmonic components. The partial erasure and the nonlinear transition shift are evaluated on the basis of the ratio between the odd-numbered order harmonic components.

Abstract: A magnetic data embedding system (or disk servo writer) includes a stack with a master disk (3) and a plurality of magnetic disks (4) mounted on a shaft of a spindle motor (6), and a rotary positioner (11) which integrally holds one or more read-only heads (71 to 74) for reading the master disk and a plurality of groups of servo heads (101 to 104) and which simultaneously turns both of the kinds of heads. The groups of servo heads have access to the top and bottom sides of the magnetic disks. The servo heads are made carry out writing to the same (top or bottom) side of each of the disks in parallel, within assigned track ranges for the respective servo heads.

Abstract: A magnetic disk medium allows embedding ID information that prevents manipulation and yet holds its uniqueness. ID information for uniquely identifying a medium is recorded separately as a master ID information on a preformatted region and as individual medium ID information on a non-preformatted region in a pre-embossed type magnetic disk.

Abstract: A magnetic data embedding system (or disk servo writer) includes a stack with a master disk (3) and a plurality of magnetic disks (4) mounted on a shaft of a spindle motor (6), and a rotary positioner (11) which integrally holds one or more read-only heads (71 to 74) for reading the master disk and a plurality of groups of servo heads (101 to 104) and which simultaneously turns both of the kinds of heads. The groups of servo heads have access to the top and bottom sides of the magnetic disks. The servo heads are made carry out writing to the same (top or bottom) side of each of the disks in parallel, within assigned track ranges for the respective servo heads.

Abstract: Track addresses for respective recording surfaces of a hard disk drive are input from a main controller 122 to pattern generation sections 130 of a pattern generator. The pattern generation sections 130 generate servo patterns corresponding to the track addresses. The generated servo pattern data are temporarily stored in pattern memories 131. A transfer control circuit 132 reads out, in parallel, the servo pattern data in the pattern memories 131 in synchronism with a servo clock. Output signals from the pattern generator 122 are supplied to recording elements of servo heads 113 via write amplifiers 121, and servo patterns are written to the recording surfaces in parallel. As a result, positional deviations between servo-tracks with the same track address due to alignment errors of the head assembly can be corrected, without the need for complicated track management firmware.

Abstract: A magnetic disk medium allows embedding ID information that prevents manipulation and yet holds its uniqueness. ID information for uniquely identifying a medium is recorded separately as a master ID information on a preformatted region and as individual medium ID information on a non-preformatted region in a pre-embossed type magnetic disk.

Abstract: A method and apparatus enables observation of a subpulse signal, which is generated due to improper transfer conditions, while reducing the effect of noises on the subpulse signal. A servo signal, which is recorded on a transfer medium by magnetic transfer, is sampled a plurality of times via a head and a head amplifier, and a data collecting device collects plural pieces of waveform data. After a computer section then compares the waveform data to find a phase difference, the phase is corrected to produce an averaging waveform of each waveform. The produced averaging waveform is displayed on a monitor in order to be used for observation of the subpulse signal.