Reizo Kaneko

Micro-step XY-stage using piezoelectric tube actuator

A novel small and simple mu m-order-step XY-stage has been developed. It consists of a cylindrical piezoelectric actuator fixed at one end to a baseplate, with one electrode inside the tube and two pairs of diametrical electrodes on the outside. A support is attached to the free end. The actuator is powered by a single cosine waveform voltage by friction force. An analysis shows that the trajectory of the substance is determined by the parameter gamma = alpha omega /sup 2//( mu g), which has no relation to its weight, where alpha is the amplitude of the support stroke, omega is the angular frequency of the single wave, mu is the friction coefficient, and g is the gravity. The final displacement of the substance has its maximum at x/sub 5//(2 alpha )=0.626 when gamma =3.76. The actuator drives the substance on the support two-dimensionally. The stroke and direction of movement are controlled with a joystick.<<ETX>>

Mass storage technology in networks

Trends and features of mass storage subsystems in network are surveyed and their key technologies spotlighted. Storage subsystems are becoming increasingly important in new network systems in which communications and data processing are systematically combined. These systems require a new class of high-performance mass-information storage in order to effectively utilize their processing power. The requirements of high transfer rates, high transactional rates and large storage capacities, coupled with high functionality, fault tolerance and flexibility in configuration, are major challenges in storage subsystems. Recent progress in optical disk technology has resulted in improved performance of on-line external memories to optical disk drives, which are competing with mid-range magnetic disks. Optical disks are more effective than magnetic disks in using low-traffic random-access file storing multimedia data that requires large capacity, such as in archive use and in information distribution use by ROM disks. Finally, it demonstrates image coded document file servers for local area network use that employ 130mm rewritable magneto-optical disk subsystems.

Development of a Micro-step XY.THETA. Stage Using Piezoelectric Tube Actuators.

A micro-step XYθ stage mechanism has been developed. This stage consists of three piezoelectric tube actuators fixed at one end to the vertices of an equilateral triangle on a baseplate. When a single cosine waveform voltage is applied to the three actuators, the quick bending motions in the same direction cause the sample to move forward by frictional force; quick bending motions tangential to the circumscribed circle cause the sample to rotate by frictional force. This stage can drive the sample two-dimensionally and rotate it in μm-order steps. The stage facilitates the positioning of the point to be measured in scanning probe microscopes (SPM). Subsequently, the sample is moved by the same actuators in the usual scanning mode and in precision Z-direction positioning. Thus this stage can be used as a micro-step XYθ stage and as a precision XYZ positioning stage, and also used as a micro-step XYθ stage for positioning a sample in optical microscopy and scanning electron microscopy.