Recently, structures having periods of nanometer scale, such as photonic crystals and biomimetic structures, have been developed. And, it is known that the optical function becomes diversified as the period of the structure becomes multidimensional. So, a highly efficient fabrication method of three dimensional nano periodic structure is required. The Talbot effect is a phenomenon in which a periodic light intensity distribution is generated by a diffraction grating and has high processing efficiency by applying it to lithography. However, there is a problem that flexibility of processing is low. To solve this problem, we propose to use multiple exposure for lithography using Talbot effect. In this paper, the structure is three - dimensionalized by rotating the diffraction grating and performing multiple exposure, and the flexibility of lithography processing using the Talbot effect is improved.

This paper describes the effects of the discharge-current waveform on the shape and removal volume of craters in electrical discharge machining (EDM). In EDM, it is known that removal efficiency, defined as the ratio of the removal volume to the volume molten by a single discharge, is no more than several percent. Hence, to increase the removal efficiency, the influence of the discharge current waveforms on the removal volume in a single discharge was investigated. Using cold tool steel plates and copper rods as the workpiece and tool electrode, respectively, the removal volume of workpiece with the polarity of positive was largest when a linearly increased and sharply turned off current was used with the pulse duration of 200μs.

Highly integrated ultraprecision machining technology is required to create tiny and complicated shapes of optical parts with high accuracy. In multi-axis control ultraprecision machining, initial setting errors that could be generated while setting a cutting tool and a workpiece may have critical influence on the machining accuracy due to the miniaturization and complexity of objects to be machined. Though several methods that compensate the tool setting errors have been already proposed, the methods require time and effort to set or remove the workpiece manually on a machine tool. In addition, the workpiece setting errors have been ignored until now. Therefore, based on a novel setting errors compensation of tool and workpiece, this study aims at developing an automated setting operation using an industrial robot to avoid human factors and to improve the efficiency of ultraprecision machining. In the proposed setting operation, the setting errors of located tool and workpiece are estimated by using an on-machine measurement device and compensated with high accuracy by modifying NC data. From the experimental result, it is found that the novel setting errors compensation can contribute to realize a fully automated setting operation for high efficient ultraprecision machining.

The Peak-of Gain Control (PGC) and Auto-Balancing System (ABS) are applied as unbalanced vibration compensation for active magnetic bearings. The PGC applied when passing through the critical speed of the rotor increases bearing stiffness and positively suppresses vibration amplitude of the rotor. On the other hand, ABS is applied at a rotation speed exceeding the critical speed and the amplitude of the rotor becomes small. It has the function of reducing the bearing stiffness. Since PGC and ABS are applied at different rotational speeds, it is necessary to switch connections. When starting up the turbo molecular pump, precise work is carried out even at the rated rotation speed. Therefore, it is necessary to suppress the casing vibration due to the transient phenomenon. Furthermore, a switching circuit for each of PGC and ABS is required. As a result, the entire circuit becomes complicated.

Therefore, in this paper, we propose PGC and ABS operation method which do not switch. Specifically, phase-variable PGC is applied, and the phase parameter of the tracking filter is adjusted according to the rotation speed. As a result, it acts as PGC when passing through critical speed and as ABS at rotational speed after passing through critical speed. Therefore, transient response by switching does not occur. Further, the switching circuit on the ABS side can also be omitted.

In the manufacture of precision electronic components, defects are detected using automatic inspection machines. When high inspection sensitivity is employed, the group of potentially defective candidates identified by the inspection machine can include many acceptable units; this can ultimately lead to an excessive number of incorrect defect detections. This study aims to develop an effective method for classifying images of defect candidates into defect images and good images. Herein, the inspection method of electronic components with various defective images generated from the true defect images is proposed.