Tdk Corporation

Sae Magnetics (h.k.) Limited

Nihon Techno Bute Limited

Katsuhiko Tomita

Masashi Shiraishi

Masanori Sakai

Takashi Honda

Takeshi Wada

Tamon Kasajima

Joichiro Ezaki

Nozomu Hachisuka

Hiroshi Ikeda

Yoshiaki Ito

Toshiaki Maeda

Yuzuru Iwai

Tomohiro Honya

Tsz Lok Cheng

Kazuo Suzuki

Seiji Fukuda

Kouichi Hatakeyama

A radar apparatus includes a modulation signal generating unit that generates a modulation signal based on an internal clock with a cycle Tc and generates a trigger signal in synchronization with the modulation signal, a carrier wave generating unit that generates a carrier wave, a modulation unit that generates and outputs a high frequency signal by modulating the carrier wave using the modulation signal, a modulation signal extracting unit that extracts the modulation signal from a component of the high frequency signal that has been transmitted via a transmission antenna, the component having been reflected by a measured object and received by a reception antenna, a detection signal generating unit that generates a detection signal, for measuring a distance to the measured object, based on the trigger signal and the extracted modulation signal, and a pulse width calculating unit that calculates a pulse width of the detection signal.

Range-finding radar apparatus with high-resolution pulse-width calculation unit

A method of testing a performance of the HGA has a step of writing information from the at least one thin-film magnetic head element onto a magnetic disk with driving the actuator for displacement by applying an alternating drive signal to the actuator, a step of reading out the information of at least one rotation of the magnetic disk by the at least one thin-film magnetic head element without driving the actuator for displacement, a step of storing the information read-out from the magnetic disk as a read-out information along a disk-rotating direction, a step of moving the HGA toward an off-track direction by a predetermined distance, a step of repeatedly executing the reading, storing and moving steps to obtain two-dimensional read-out information along the disk-rotating direction and the off-track direction, and a step of determining, from the two-dimensional read-out information, an off-track position where the read-out information becomes maximum at each position along the disk-rotating direction, the determined off-track positions being recognized as displaced positions of the actuator in response to the applied alternating drive signal.

Performance test method of head gimgal assembly with precise positioning actuator

A method of testing a performance of an HGA including a step of obtaining a displacement performance of a precise positioning actuator by driving this actuator to displace and by executing a track profile measurement of at least one thin-film magnetic head element.

Performance test method of head gimbal assembly with precise positioning actuator

A method for testing a thin-film magnetic head with a MR read head element includes a step of applying a low-frequency or DC external magnetic field to the thin-film magnetic head from a stationary magnetic field generation unit, a step of executing a high-frequency amplification of an output from the MR read head element under the application of the external magnetic field to provide a high-frequency amplified signal, a step of deriving only a high-frequency component from the high-frequency amplified signal to provide a high-frequency component signal, and a step of judging whether the thin-film magnetic head occurs a noise or not by using the high-frequency component signal.

Method and apparatus for testing thin-film magnetic head

A method and apparatus for testing a magnetic head provided with at least one MR transducer. The method includes a step of applying a sense current varying with respect to time to the MR transducer element via input/output terminals of the MR transducer element, and a step of measuring a terminal voltage across the input/output terminals of the MR transducer element to check varying resistance characteristics of the MR transducer element with respect to the variation of the applied sense current.

Method and apparatus for testing a magnetic head during manufacture

A method and apparatus for testing an integrated magnetic head assembly for normal operation. The head assembly includes an inductive write element and a MR read element. The method includes a step of applying an external alternating magnetic field to a plurality of magnetic head assemblies which are aligned on a head block and are not yet individually separated from the head block, in a direction perpendicular to an ABS of the head block, and also applying high frequency current to the inductive write element so that alternating leakage magnetic field from the inductive write element is applied to the MR read element, and a step of measuring varying resistance characteristics of the MR read element with respect to the variation of the external alternating magnetic field and to the variation of the alternating leakage magnetic field.

Method and apparatus for testing integrated magnetic head assembly

To perform digital processing of cyclical waveform signals that include random noise with high accuracy and high reliability without being practically affected by the noise. This is a waveform signal processor into which cyclical waveform signals are input and which outputs corresponding signals. It samples a cyclical waveform signal a plurality of times and then, based upon the obtained sampling values, it performs a Fourier Transform for all the various cycles. Next, the phase angle of a pre-selected frequency component in the Fourier series is determined based upon the Fourier Transform. Then a sampling point at the same phase for all cycles is specified by using the phase angle as a reference. The average of the sampling values at the same phase is calculated and output.

Waveform signal processor with selective sampling

In a magnetic disk supporting device of a type that the longitudinal direction of the supporting device extends in the tangential direction of the tracks of a magnetic disk, the direction of float rails on the slider of the magnetic head is the same as the longitudinal direction of the supporting device, and the slider is fixed to the lower surface of a central tongue portion constituting a part of the supporting device at a position that the front end of the slider does not overlap with a lateral frame as a part of the supporting device, whereby stable operation of the magnetic head can be obtained.

Growing community of inventors

Tokyo, Japan

Katsuhiko Tomita