Hideki Nihei

A direct search shape optimization based on complex expressions of 2-dimensional magnetic fields and forces

A 2-dimensional shape optimization method for magnetic materials and conductors such as those of induction machines has been developed. The method combines a steady state AC field analysis based on complex expressions of magnetic fields, a method to compute Lorentz force in complex form and the direct search method. As an example, shape optimization of a single sided linear induction motor is reported.

Stacked Optical Disk Drive for Multimedia Files

A stacked optical disk drive with multiple optical heads has been developed for large-capacity multimedia files. This drive will be suitable for such applications as a network database through LAN, a picture library Including moving pictures, and an editing machine for broadcast use.

10-mm-thick head mechanism for a stacked optical disk system

A 10-mm-thick head mechanism for a 30 GB, multi-head type stacked optical disk system has been developed. A pair of linear brushless motors are utilized as the coarse actuator, and a 2D motion lens actuator is utilized as the fine one. The average access time is 150 ms. The track following characteristics are tested. The tracking error is 0.03 micrometers in amplitude with a 3600 rpm, 254 mm diameter disk.