An access mechanism for achieving high-speed head positioning for optical disk drives was developed. The carriage acceleration reached 240m/s^2 while the compact size was maintained. The performance and small size was achieved by developing voice coil motors with multi-pole magnetic circuits and a five-element driving coil assembly. Compared to the conventional single-pole actuators of the same thickness, the actuator force constant was doubled. Size was also minimized by having the lower yokes of the magnetic circuits serve as roller-guide surfaces.

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This paper describes the way of miniaturization of a surface acoustic wave(SAW)linear motor and characteristics of the miniaturized motor. A stator transducer can be miniaturized by operation at higher frequency. The miniaturized SAW linear motor could be successfully driven at the operating frequency of 50 MHz and 70 MHz. The limit of miniaturization, namely driving frequency limit, is also discussed. It seemsthat the limit depends on the surface roughness of the stator transducer.

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In order to clarify the design guidelines for vibrational friction motors, their driving characteristics were investigated theoretically and experimentally. First, the effects of shape and vibration mode of the stator on the driving efficiency were analyzed by calculating the tangential velocity of the stator using FEM without considering the collision between the stator and the rotor. Next, the relationships between the conditions of the collision surface and the driving force were measured with an experimental apparatus of which structural parameters were best tuned according to its dynamic model. With these analysis and experiments, the best conditions of the stator shape, vibration mode and the collision surface were clarified.

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In recent years as for the mechanical watch, the persistent demand is existing irrespective of country even in the present when the quartz watch became a mainstream and those many are classified as a high-class watch. Furthermore the demand to a high-class mechanical watch increases year by year and thought that there is the change of the following recognition in the background. Firstly, the mechanical watch is receiving the settlement as a high-class watch and recognized as`the instrument that expresses person'of the personality that I acquire from'the instrument that knows when'. Secondly, the mechanical watch is recognized as universal worth. Thirdly, the mechanical watch is recognized as an object of industrial art. The middle of the background like that I explain with this manuscript the chronograph watch that belong to the classification of a top among the mechanical watch, about the result that we developed it by using 3 dimension CAD and analysis technology, to measure the shortening in the development period.

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Simple and accurate system to measure structural damping coefficients was investigated. A new system was developed using a microphone as a vibration sensor and a personal computer for signal processing. Compared with the previous system using a lasor doppler vibrometer and FFT analyzer, the new system was only about 1/10 the cost of previous system, almost the same measurement accuracy was obtained, and measuring time was reduced to less than 1/10 that of the previous system. From these results, the new measurement system was validated for simple and accurate measuring of structural damping coefficients.

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A novel micropump that has two active and normally-closed valves was developed using micromachine technology. This micropump can pump in forward and backward direction, and hold the fluid without consuming energy even when the fluid source has some pressure. These normally-closed valves are manufactured by filling up silicone rubber paste after bonding a glass substrate and a silicon substrate. Silicone rubber works as a"gate"for shutting off the flow. Therefore, high pressure-resistance micropump is realized with no influence of fabrication error. In this paper, basic characteristics of this micropump about flow rate, outlet pressure and pressure-resistance are described.

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