Hitachi-high-technologies Corporation

Hitachi, Ltd.

Other

Hitachi High-tech Electronics Engineering Co., Ltd.

Shinji Homma

Masayoshi Takahashi

Masami Makuuchi

Masahiro Watanabe

Toshihiko Nakata

Norio Chujo

Yoshihiko Hayashi

Takenori Hirose

Ritsuro Orihashi

Teruaki Tokutomi

Kaifeng Zhang

Takehiro Tachizaki

Tsuneo Nakagomi

Ritsurou Orihashi

Wen Zheng Li

Yoshihiro Sakurai

In a method and an apparatus for inspecting a thermally assisted magnetic recording head element, a specimen is mounted on a table movable in a plane of a scanning probe microscope device, evanescent light is generated from a portion of light emission of evanescent light of the specimen, scattered light of the evanescent light is detected by moving the table in the plane while a cantilever of the scanning probe microscope having a probe is vertically vibrated in the vicinity of a surface of the specimen, and an intensity distribution of the evanescent light emitted from the portion of light emission of evanescent light or a surface profile of the portion of light emission of evanescent light of the specimen is inspected using position information of generation of the evanescent light based on the detected scattered light.

Thermally assisted magnetic recording head inspection method and apparatus

The present invention provides a technique for converting burst data to digital data, applying FFT operation to 2(n is an integer) pieces of digital data in response to any start signal synchronized with a sector signal, applying a window function centered around data corresponding to a frequency of a burst data signal component before the FFT operation, and performing head positioning based on a result as the detected value of the burst data.

Inspection apparatus and inspection method of magnetic disk or magnetic head

An inspection apparatus and method are disclosed for inspecting a magnetic disk or a magnetic head. A first reference signal generating source generates reference signals of a controllable oscillating frequency, and a signal switching means selects either a reference signal or test data reproduced by the magnetic head. Factors such as offsets and gain differentials among signal distribution paths, phase shifts of sampling clocks supplied to a plurality of AID converters, and frequency-dependence of the transfer function and phase response of signal paths are identified so that errors due to these factors can be detected. Based on the detected values of these factors and errors, reference signals are utilized to compensate test data errors.

A magnetic characteristic inspecting apparatus including a plurality of disk rotating devices or a plurality of magnetic heads include a unit for switching output signals of write signal production units or allocating the output signals to the magnetic heads, a unit for switching signals read from the magnetic heads or allocating the read signals to measurement resources, and a unit for selecting any of the disk rotating devices synchronously with which the measurement resources will perform measurement. The write signal production units and measurement resources are shared among inspections of the plurality of disk rotating devices or the plurality of heads.

Magnetic characteristic inspecting apparatus and inspecting method using it

A testing apparatus of a magnetic recording medium for conducting a test on the magnetic recording medium by using reproduced data obtained through reproduction of the magnetic medium, including a plurality of conversion means for converting the reproduced data into digital data, holding means for holding the digital data converted by the plurality of conversion means, data processing means for performing a calculation process on the digital data held by the holding means in relation to a magnetic characteristic of the magnetic recording medium, and analysis processing means for performing an analysis to determine whether or not information obtained by the data processing means satisfies a certain condition.

TESTING APPARATUS FOR CONDUCTING A TEST ON A MAGNETIC RECORDING MEDIUM OR A MAGNETIC HEAD, THROUGH RECORDING TEST DATA ON THE MAGNETIC RECORDING MEDIUM AND REPRODUCING RECORDED TEST DATA THEREFROM BY MEANS OF THE MAGNETIC HEAD

Testing apparatus of magnetic recording medium or magnetic head including a plurality of analog-to-digital converters which convert reproduced testing data into digital data

Growing community of inventors

Nakai, Japan

Shinji Homma