An experimental method is presented to measure micro-thermal deformation of an optical pick-up base using the holographic interferometry. The thermal deformation of an aluminum pick-up base, manufactured from die-casting process, was measured in actual thermal environments using the present holographic interferometry. The experimental result using the holographic interferometry was compared with Finite element analysis with initial surface stress conditions obtained from X-ray diffraction measurements.

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In ODD servo systems, the conventional seek control technique utilizes only the coarse actuator without any maneuvering of the fine actuator. In this paper, we propose a new Seek Control Scheme (SCS) that employs both the coarse and fine actuators. With assistance of the fine actuator, however, the seek control system is designed such that its performance is guaranteed for various disturbances and mechanical limitations. Simulations and experiments show the improvements of the proposed direct SCS implemented on a practical DVD-ROM drive system.

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This paper deals with the robust control using H_<&vprop;> loop-shaping for an optical disk drives (ODD). The shape factor used in this process is a firmware servo loop and the robust H_<&vprop;> loop-shaping controller using this shape factor is designed, then it is applied to a commercial optical disk drives. A shaping factor to open loop is critical factor in the design process, therefore, we should consider what is desirable loop shape and the disturbance characteristics. Based on our previous work about the disturbance characteristics [1], a controller design considering these characteristics can be done.

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Plasmon-enhanced (PE) optical heads were designed and fabricated with a plasmon-enhanced optical element and optical waveguides, sliders and suspensions. Flying type and contact type sliders are designed for the optical head. The difference between the flying height at the PE-optical element and at the location of the minimum flying height is designed within 15 % for the flying height around 10 nm. The contact flying head is designed to minimize the effect of the flying pressure. The most important issue for the optical heads is the shrinkage features of the slider with small optical guides.

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Fujitsu has developed an optical flying head (OFH) containing a thin-film coil and a high numerical aperture lens for magneto-optical (MO) disk drives. Experiments show successful writing and reading MO media. We explain the design and testing of the OFH.

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Some micro-optical devices have recently been developed and created with OFH (Optical Flying Head). Many sliders for OFH and optical component systems have been introduced. However, the mechanical system that makes of suspension, swing arm and VCM part has not been showed interesting in it. For embodiment of the micro optical device, the mechanical actuating system is also designed and developed. In this paper, we give an overview of an optical disk actuating system using an OFH that is suitable for use with removable optical media.

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A prototype of the positioning mechanism suitable for a near-field optical recording system was introduced. A novel suspension and a carriage structure were newly developed for the mechanism. A novel control technique was presented to suppress the off-track caused by friction force using an acceleration sensor installed in a carriage. The performance of suppressing force disturbance was evaluated.

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In recent years, the effect of air floating particle originating from diesel car exhaust gas on the human body has become a problem. In this research, so as to investigate floating particle distribution in the living environment, we manufactured a wearable terminal with a pump, which can sample simultaneously the particle with position, temperature, or humidity information. We so could build up an environmental monitoring system that does not require specialist's skill. By carrying out quantitative analysis (ICP) of the air floating particle matter sampled using this terminal, it showed that this system was useful to local air environment assessment.

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A method to diagnose wear of lathe cutting tools for precision parts of watch was studied. Theoretical analysis of cutting tool's vibration was made using dummy tools. It was demonstrated that stick-slip vibration occurred and level of first resonance frequency increased remarkably when a cutting tool wore. From this result, the types of prototype modules, analog and digital, were fabricated. The digital type can transmit information periodically with a transmitter, and the remote surveillance of a cutting state will be attained. This module is called "Nature Interfacer for failure diagnosis."

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This paper proposes a thickness measurement method of silicon-oxide and poly-silicon film deposited on 12" silicon wafer for spin etcher. Halogen lamp is used as a light source for generating a wide-band spectrum, which is guided and focused on the wafer surface through a optical fiber cable. Interference signal from the film is detected by optical sensor to determine the thickness of the film using spectrum analysis and several signal processing techniques including curve-fitting and adaptive filtering. Test wafers with three kinds of priori-known films, poly-silicon and silicon-oxide, are measured while the wafer is spinning at 20Hz and DI water flowing on the wafer surface. From experimental results the algorithm presented in the paper is proved to be effective with accuracy of maximum 1.8% error.

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Results on the investigation of vacuum compatible hydrostatic air bearings are presented. The hydrostatic air bearings consist of three pumping grooves and labyrinths around the bearings and put in a vacuum chamber for test. The sealing effects of labyrinth width and clearance, and the sensitiveness of pumping ducts for the chamber pressure were investigated. The theoretical results show that the outer labyrinth width L_3 and the diameter of outer pumping duct D_3 are the most sensitive parameters, and the chamber pressure P_c decreases exponentially with L_3 and D_3 increase. On the other hand, the chamber pressure P_c increases in quadric with the labyrinth clearance g increases. It was found that the theoretical result agrees with the experiment qualitatively.

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This paper theoretically investigates the performance of the seal system of aerostatic thrust bearings used in a high vacuum chamber. This thrust bearing has several stages of viscous seals and exhaust grooves around it. Each exhaust groove is connected to a separate vacuum pump in order to achieve a vacuum chamber pressure of less than (10)^3 Pa. The vacuum chamber pressure is affected by various design parameters such as seal gap, seal length and conductance of exhaust tubes. In this paper, the influences of these design parameters on the vacuum chamber pressure are discussed.

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This paper surveys recent advances in the field of IC-processed actuators and distributed microelectromechanical systems (MEMS). IC-processed actuators are expected to open a wide range of industrial applications on the near term. The most promising investigations deal with high-aspect ratio electrostatic microactuators suitable for use in numerous technical fields such as super-compact computer peripheral devices and integrated watch mechanisms. Because the silicon micromachining technology have the potential to integrate both mechanical components and control circuits, MEMS-based active control of microscopic and macroscopic structures appears to be one of the most promising challenges for the next decade. As a first step towards new generations of MEMS-based smart structures, recent investigations dealing with IC-processed distributed systems are briefly introduced in the second part of the paper.

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In order to increase vibration rejection ratio for semi -conductor lithograph machines, we developed serial active vibration isolation system in which two isolation systems placed in series. Each isolation system is composed by air mount and VCM (voice coil motor). This report shows optimization of mechanics and control for serial isolation system.

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This research proposed two types of power generating systems using machinery and human vibration. In both types, mechanical impedance was dynamically controlled to obtain the maximum output power for arbitrary input amplitude. The dynamic models, prototypes and performance of these types were shown.

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We have developed the dive computer watch Cyber Aqualand. It can communicate with PC by downloading the diving data, which is recorded during the dive, and uploading the various user customized data from PC to watch. It also can communicate some data between watches. And with PGM technology, Cyber Aqualand realized an easy updating the firmware and the software, which contribute to lower the development cost and higher the development speed.

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A paper feed process of a reverse roller type feed mechanism is simulated by a FEM software considering a modified Coulomb friction. The results show that the friction force acting on a paper does not depend on the normal force but the reverse torque. Based on this, a simple analytical model to predict the paper feed velocity is proposed.

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An improved controller design and implementation technique for electrophotographic process (EP) was proposed. The new controller was modified from a previous design to address two additional issues for generic EP platforms, i.e. reducing position-dependent disturbances and reducing system sensitivity to manufacturing variations in EP engine and consumables. To handle position-dependent periodic disturbances, a digital repetitive controller was developed and implemented using spatial sampling. Second, system variations due to manufacturing variations as well as consumable changes were incorporated into the design of a two degree of freedom (TDOF) robust controller. The controller is optimal in the sense that it minimizes the size of the sensitivity function from a set of disturbance signals to a set of measurable signals critical to print quality. Trade-offs between system performance and robustness to system modeling uncertainties was considered in the synthesis and optimization formulation. The effectiveness of the proposed controller design and implementation technique was numerically and experimentally verified.

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A basic research is being carried out on the transport of particles and the particle size classification in the electrostatic traveling field. A particle conveyor consisting of parallel electrodes was constructed and four-phase traveling electrostatic wave was applied to the electrodes to transport particles on the conveyor. The following were clarified by the investigation : (l) The direction of the particle transport did not always coincide with that of the traveling wave but partially changed depending on the frequency of the wave, the particle diameter, and the electric field.(2) Particles were classified with size under the voltage application of appropriate frequency.

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Theoretical aspects of backwards transport on a traveling wave device are discussed. It is clarified that a countermoving harmonic wave can account for this phenomenon. Using a perturbation approach the critical frequency and the critical altitude are ca1culated and compared with numerical results. It is shown that both are in good agreement.

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The ionic wind is caused by collisions between ions produced by discharge and neutral molecules in the air. The characteristic of the ionic wind in corona devices is investigated through Computational Fluid Dynamics to better understand this phenomenon. The flow fields of the ionic wind are obtained. It is shown that the λ-shaped flow appears on a cross section and momentum transfers along the axis.

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A simulation model of separating discharge between a sheet and a grounded electrode is verified. The discharge gaps, the discharge density (the number of discharges in 30 mm along the separating direction) and the potential distribution on the back-side of the sheet after the separation are calculated and compared with the experimental results. Although the discrepancy is recognized in the number of discharges in high electrification level, this model can be used for the study of preventing harmful effects of separating discharges.

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Electrostatic pull-off of electromagnetic bead chains is investigated to improve two-component magnetic development system of electrophotography by the estimation of forces applied to the beads. The dependency of the magnetic bonding force of chains on the magnetic field and bead diameter was clarified and the mechanism of the electrostatic pull-off was verified by the comparison of numerically calculated magnetic force with the measured electrostatic pull-off force.

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A scattering toner (sometimes called toner clod) is one of the big problems in a two-component development system, especially in color imaging system. The scattering toner phenomena are analyzed by microscopic visualization technique and interactions with airflow caused by the magnetic carrier brush are clarified. The boundary area between color developer and photoconductor (nip area) are observed using a high-speed camera with a microscopic lens. A special sucking airflow is generated at the edge of developer case and the scattering toner phenomena in the nip area are restrained by this airflow. The decreasing pressure in the developer case is resulted from the movement of the magnetic carrier brush on the developer sleeve. As the result two contrary airflows exist close to each other. One is the airflow on the surface of the sleeve produced by rotating roller and the other is by the movement of the magnetic carrier brush. In addition, the stronger is the sprinkling movement of the magnetic carrier brush, the more scattering toner phenomena are observed.

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A preliminary investigation is conducted on electrostatic inkjet phenomena. High voltage is applied between an insulative capillary tube filled with water and a metal plate electrode. Inkjet phenomenon is observed at the dark discharge under conditions of appropriate tube diameter and water level. At the beginning of corona discharging, however, water mist is dispersed at wide angle from the tip of the tube. At higher voltage, water mist becomes to be dispersed like spray. Application of pulsed voltage can form a droplet that is synchronized with the pulse. This phenomenon is expected to be applied to a new inkjet print head.

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A new paper-separation system is proposed to realize a highly reliable paper handling system for printers. The system consists of a pair of parallel plate electrodes and a paper pile between the electrodes. In this system, electrostatic separation of a sheet of paper on the top of the pile was realized when the applied voltage exceeded a threshold. Experimental results agreed with numerical ones calculated by the FEM on the electrostatic field.

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A non-magnetic and non-contact AC development system has been numerically investigated using a two-dimensional dynamic model. Simulation of toner dynamics in the development process was carried out using the Finite Difference Method (FDM) for the electric field calculation and the Distinct Element Method (DEM) for the calculation of charged toner motion in the electric field. Calculated results showed fairly good agreement with experiments.

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It is essential to ensure their reliability to produce a MEMS on commercial scale. Reliability problem in inkjet printhead is also very important. To eject an ink drop, temperature of heater must be high so that ink contacting with surface reaches above 300℃ on the instant. Its heater is embedded in the thin multi-layer in which several materials were deposited. MEMS processes are the main sources of residual stresses development. Residual stresses are the main factor reducing the reliability of MEMS devices. We measure residual stresses of single layers that consist of multiplayer. We optimize thickness of each layer using them so that maximum stress in residual stress distribution can be minimized.

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This paper proposes four types of classification methods, by combining of two feature extracting approaches (TPCA/KPCA) and two classifiers (k-NN/ANN), to develop the multi-aimed face recognition system. Experimental results using several face databases confirm that the classification method combined with "KPCA+k-NN" is most suitable for the recognition tasks.

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A profile measurement system using an optical stylus was proposed, which is robust to speckle included in the reflected light from the object surface. This measurement system consists of a displacement-measurement optical system using focus-error detection and a system that only measures speckle noise. Measurements were taken of engineering surfaces for which speckle are easily attained, and it was found that the proposed measurement system could remove the effects of speckle noise and obtain a surface profile close to that obtained by a mechanical stylus instrument.

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A two-axis antenna-stabilizing-control device which does not need a level sensor was developed. The control incorporates a zero-servo method, which zeros the two gyro outputs by rotating an antenna both with an azimuth motor and an elevation-servo motor. But, a Jimbal-lock and an unlapping of cable occur frequently in high-elevation angle, and large pointing errors resulted from them. We solved the problems by using servo-deflection-correction method and the estimated rewind method.

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The magnetic recording head with DLC (Diamond Like Carbon) pad is one of the potential solutions to extend CSS (Contact Start Stop) technology to the low head-disk spacing. In the present paper the study of DLC Pad and ABS design was carried out with LZT (Laser Zone Texture) disk and smooth disk. The occurrence of tipping accelerated the wear of DLC pad, lubricant degradation and COC wear on the disk. The results showed that the magnetic recording head, which has optimized ABS and optimized DLC pad, has good anti-stiction capability and enough CSS reliability at 15nm FH on the LZT Media having low bump height.

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This paper describes the comparison with the experimental flying heights and the simulated flying heights, which were calculated by using the Linearized Boltzmann equation and the conventional modified Reynolds equations. The experiments were measured under the ambient pressure from atmospheric pressure to 6.7x(10)^<-3> MPa. The Linearized Boltzmann equation were almost the same as to the experimental results from the high spacing range to the low spacing range of 10nm. At the slider spacing of 10nm, it was confirmed that the difference between the experimentally measured results and the calculated results of the Linearized Boltzmann equation was less than 5%.

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We experimentally investigated the effect of lubricant on both the glide avalanche height of disks and slider vibration due to slider-lubricant contacts using a flying height tester equipped with an acoustic emission (AE) sensor. Unfinished glass disks, which are used as magnetic disk substrates, are also used in flying height measurements. the glide avalanche height of the glass disk was defined as the flying height at which the AE signal increased sharply as flying height or disk velocity decreased. We also made use of glass substrates from the same manufacturing lot that were coated with diamondlike carbon, lubricated with perfluoropolyethers and annealed at various conditions to adjust the thickness and the bonding ratio. These lubricated glass disks were placed in the flying height tester and the AE signal was monitored as a function of disk velocity using the same slider. We determined that the lubricant thickness should be reduced to decrease the glide avalanche height and the bonding ratio should be increased to reduce slider vibration.

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The technique for detecting the head-disk contacts by using the read back signal was investigated. A spectrum of the read back signal was measured and the time history of the peak height at the recording frequency was monitored by using a spectrum analyzer to determine the fluctuation of the read back signal (peak to peak values and sigma values). The track average amplitude (TAA) and the acoustic emission (AE) signal were also monitored. The peak to peak and the sigma values proved to be sensitive enough to detect the slider-disk contact and so was the AE sensor. The TAA, however, was not sensitive enough. On the spectrum of the read back signal, some side band peaks were observed near the recording frequency when the slider was in contact with the disk. The differences in frequency between the peak of the read back signal and side band peaks showed the vibration mode of the head ginbal assembly (HGA) caused by the slider-disk contact.

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In this paper, the corrosion characteristics on the magnetic media of the hard disks were analyzed. A commercial hard disk was compared with disk treated by acetone. It was found that the corrosion spots for the both disks are linearly related to the heating time. The corrosion spots of the commercial disk are increased at the rate of about 19.33 spots/hour while the disk treated by acetone prior to heating increased at a rate of 55.47 spots/hour. It was noted that due to the small changes in the thickness of Z-Dol, the rate of change of corrosion spots changes drastically.

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The main subjects to be solved for realizing contact recording systems are the reduction of head wear and head vibration. Although many studies have been reported about the latter, few reported on the reduction of head wear. For this purpose, we investigated pin wear on various thin-film disk surfaces. We compared roughness of disk surfaces and molecular weight (MW) of lubricants. The results showed that the pin wear became larger as the MW was smaller or roughness was large. In addition, we found the tape burnishing of disk surfaces was effective in wear reduction.

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This paper presents an analytical and experimental study of friction-induced bouncing vibrations of a flying head slider in a near-contact regime by using a 2-DOF slider model in a translation and pitch motion. During calculation of contact force characteristics between the trailing pad and disk, we considered asperity contact including bulk deformation, adhesive force of lubricant and friction force in the real contact area. We numerically simulated the dynamic behavior of the slider in the near-contact regime. As a result, we can obtain the hysteresis behavior of slider bouncing vibration and severe bouncing vibration with some super-harmonics as seen in the experiment.

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This paper deals with experimental identification of the stiffness and damping in dynamic collision between a slider and a magnetic disk whose substrate is Al and glass. The contact force and damping were identified so as to minimize root mean square value of error between the experimental data and the analytical results of a single DOF slider motion. From comparison of the six different damping force models, it is found that the contact force due to penetrating depth can be accurately estimated by Hertzian contact theory and that the damping force is proportional to velocity and contact area. The effective damping coefficient in repulsing process is more than two orders larger than that in penetrating process in an Al disk. The damping of glass disk is almost zero. The damping effect at collision is caused not by lubricant, but by the coated layer and the substrate material.

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To reduce head wear to develop future hard disk drives, we introduced a new burnishing technique (Contact Burnishing : CB) using a hemispherical diamond slider and compared pin wear on disk surfaces with and without the burnishing. The results showed that the pin wear was reduced by the introduction of the burnishing technique. The reason of wear reduction by CB was considered to be the reduction of asperity heights.

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There are many challenges in head-to-tape interface problems in helical scan system due to its complex air pressure distribution caused by rotating drum, head mounting windows and head protrusion. In this study, air pressures distribution around the rotating drum was measured using minute differential pressure meters that are composed by semiconductor pressure sensor and extended flexible proboscis. Computational simulation of the pressure and vortex inside and outside of the rotating drum was evaluated also, taking into account the effects of inner head mounting bases, holes and head mounting windows. These results of the study were found to be extremely useful for design a rotating drums in helical scan system.

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To improve position accuracy-non-repeatable run out (NRRO)-in HDDs two criteria for optimizing position-signal quality were devised. One is minimum position sensitivity. Position-signal nonlinearity is mainly caused by interaction between trackwidth, erase band and sensitivity distribution of head. In the amplitude pattern, NRRO was reduced by 15% of track pitch (Tp) with increasing trackwidth (Twr) by 10% of Tp while Twr/Tp ratio was less than 0.61. Another criterion is the burst-bit density. NRRO dispersion was within 0.5% of Tp when the burst frequency was optimally set.

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Areal recording density of hard disk drive (HDD) is growing rapidly with increased track density and linear bit density recently. High track density requires precise head positioning and high servo bandwidth. The dual-stage actuation system using MEMS actuator has been considered as one promising precise positioning solution. However, the frequency of microactuator may shift from its mean value during MEMS fabrication process. It is difficult for control system to compensate its 1^<st> resonance frequency to achieve high servo bandwidth. In this paper, a robust solution is proposed to minimize microactuator's resonance frequency shift so that its 1^<st> frequency is insensitive to the effects of sources of processing variability and effective compensatory for high servo bandwidth.

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This paper describes the calculation method of a solution and a group of unknown parameters such that the solution of a non-linear partial differential equation containing a group of unknown parameters satisfies separately given constraints. This method can be applied to various problems, including the prediction of the equilibrium point of an extremely thin air film gap between a head slider and a rotating disk in a magnetic disk apparatus. Accurate prediction of this equilibrium point is of vital importance in the design. This prediction is difficult if the shape of the slider is complex, the slider is running with a skew angle, or differences in speed along the slider need to be accounted for. By employing the current method, however, precise predictions can be made with fewer iterations and therefore in a shorter time.

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The shape of the trailing or leading edge of an E-block arm was modified from a blunt shape to a fin or round shape. The airflow around the arm tip was measured for the different arm edge shapes using a hot-wire anemometer, and the off-track vibration of the slider was measured using a laser Doppler vibrometer (LDBV). In the airflow measurements a peak around 4 kHz was found in the power spectra of the flow fluctuation for all arm shapes. The lowest magnitude of this peak was observed for the round type. The round trailing edge type resulted in a 10% reduction in the RMS amplitude of slider off-track vibration in the 2-20 kHz frequency band as compared with the reference arm.

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This paper proposes a human-machine interface system using bio-potential signals, such as EEG, EMG, and EOG, and investigates its possibility of applying to control a mobile robot. To investigate the feasibility and the characteristics of the bio-potential interface system, teleoperation experiments of the robot are carried out. By comparing the experimental results with those obtained using a conventional mouse interface, the effectiveness of the proposed system is demonstrated.

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This study shows a method to measure precisely the seismocariogram (SCG) of patient who lies down in the MRI machine. In healthy volunteers methods that exclusively reduce the gantry vibration were examined by analyzing the gantry vibration during MRI scanning and the SCG using a piezoelectric acceleration sensor. Commercially available damping sheet can reduce the noise-vibration caused by MRI gantry.

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This paper is a study on the measurement and valuation of touch sensation of various kinds of clothes. The tactile sensor with PVDF film as the sensory receptor and the device for moving the sensor are assembled. The human haptic feelings of wear of several clothes are examined by means of questionnaires and compared with the output of piezopolymer sensor. The measured objects are underwear and polo shirts with total 13 sheets. Comparison with the results shows that the PVDF sensor well describes the tactile perception of human.

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