Mass production of ULSI devices requires a 12-inch silicon wafer to have a site flatness better than 0.1 μm/30mm. In addition, film thickness, which varies across the wafer, must be polished to within ±5% uniformity. In order to meet these requirements, the machining process has been replaced from batch to single-wafer and from one side to both sides. This paper shows that all ordinary oscillation methods in abrasive machining can be converted to a linear oscillation method where a tool oscillates on the center line of a workpiece. For linear oscillation polishing with a viscoelastic and wear polisher, equations for surface generation were obtained by using the clearance between a workpiece and a tool. A polishing simulation program was newly developed on the basis of these equations. The calculation procedures for stock removal and optimum oscillation speed, and polishing conditions for high flatness are shown. It is also clarified that it is possible to polish within ±1% uniformity with the optimum oscillation speed control.

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This study deals with developing a new method of machining curved holes with a variety of curvature. Mechanical engineers have taken it for granted that drilling is to machine a straight hole. Therefore, straight holes have been used even in unsuitable cases, for example, pipe lines used in pneumatic or hydraulic equipments and water channels built in molds. They cannot be machined in arbitrary shape and arrangement. This prevents the equipments from being minimized and deteriorates the productivity of molding. To solve these problems, it is strongly required that the curved hole machining method. Hence, to machine curved holes, we have developed a new device consisting of a helical compression spring, wires, and pulleys. However, the curvature of curved holes by the device was limited to a certain one. To overcome the functional problem, slider crank chains are introduced in the device. From experimental results, it is found that the improved device can machine curved holes with a various curvature.

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A synthetic method for generating arbitrary number of not the same but similar texture images has been developed. The method includes processes to extract basic shape elements from texture images originating in actual objects, to select them to reappear the image features and to arrange them in an image plane. The authors have already proposed the shape-pass type filter bank assuming that the sensual impression mainly depends on minute shapes existing in the texture images. By use of nine basic shape elements, namely black/white-roof, black/white-line, black/white-snake, black/white-pepper, and cliff, natural texture images originating in actual objects have been characterized by feature vectors in a nine dimensional space. To generate arbitrary number of similar texture images, minute shape pieces are collected from original texture images and arranged so that the feature vectors may become locally similar to the original images. By the method, a number of similar texture images have successfully been generated, and the results of questionnaires on the synthesized texture images to universities students have shown the effectiveness of the method.

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Thread stripping is one of the typical failure modes of threaded assemblies subjected to static tensile overload, but it has not been recognized as a failure mode under dynamic loading. However, the accidents were reported recently that the stripping had occurred in two different types of threaded assemblies subjected to repeated tensile load. If these events are true, we should care about the stripping strength of threaded assembly in service as well as self-loosening and fatigue failure.
This study aims to confirm the possibility of the stripping in dynamically loaded threaded assemblies, and to clarify the failure mechanisms so as to avoid such types of failure. Experimental investigations for different types of bolt-nut joints are performed, and it is clarified that the stripping may occur by three different causes: (1) reduction of the number of threads engaged due to the fatigue crack growth at the first thread root of a bolt, (2) increase of the load share rate due to the permanent deformation or the permanent set of a specific thread (or threads), and (3) fatigue crack initiation at the thread root of a nut.

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In manual machine operation, human operators could perform their task well and swiftly, if they could acquire sensory information helpful to the performance effectively. In this research, the effectiveness of active visual feedback has been investigated. As the feedback devices, two kinds of head mounted display (HMD) and LED array have been examined. The objective operation is to make a small-diameter hole onto an aluminum workpiece with a carbide drill and the feedback information is cutting force. The information has been given to the operator by geometrical charts in HMD and by brightness change in LED array. As the results, the see-around see-through type monocular HMD is superior to the see-through type binocular HMD as the visual feedback device, because the former can give wide eye sight to the operators. In addition, the geometrical charts are superior to the luminance change in improvement of operating efficiency and reduction of workload. Among the geometrical charts examined, sector chart is more effective than bar chart.

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Reduction of the number of pixels for image template matching is useful to perform the high speed matching. This paper describes methods to extract partial pixels in a template image for high speed template matching and evaluates the reliabilities of the matching results by the methods. The 15 types of methods to extract partial pixels were applied to the 50 kinds of experimental images and all matching results were evaluated. The filter to detect the maximum strength of the plane edges to the eight directions recorded the higher SN ratios in the matching results. On the other hand, it was found that the conventional method that extracts pixels at a constant interval was not useful for many experimental images.

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To experiment the feasibility of "flexible machines, " we build a cellular-type machine consisting of distributed autonomous intelligent units. However, it is difficult for a cellular-type machine to exhibit cooperstive behavior of many autonomous units. In this paper, we propose a method for cooperation of cellular-type machines with an example of a "Cellular Automatic Warehouse."

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A method of detecting foreign materials in the visual inspection of an LCD with its protective film in place, without being affected by scratches or dust on the surface of the protective film, is described. In this method, which is based on the light-section method, a fan-beam laser light is scanned over the surface of the LCD to obtain a set of light-section time-series images. Those images are composed into a horizontal cross-section image for the specified depth and internal foreign materials are detected from that image. By using commercially available 1300 by 1030 pixel high-resolution CCD cameras, fibers as small as 50μm in diameter and particulate contamination as small as 100μm in diameter can be detected. Furthermore, by selectively reading a specified region of the camera image, the 600 frame/s image reading speed that is required for in-line inspection can be attained.

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This paper describes a measuring method for the eccentricity and some lower-order transmission errors of the rotating gear. The amplitude and the phase of the eccentricity are estimated by the harmonic analysis on the transmission error between two pinion gears meshing together the object gear. This method measures not only the gear eccentricity generated during the manufacturing process but also runout and deflections of the gear shaft and its bearings during operation. The transmission error of the meshing three gear system was measured by two encoders and a pulse counter connecting to the personal computer. The amplitude and the phase of the gear eccentricity were calculated by the fast Fourier transformation independently of the systematic errors and the misalignments of the pinion gears and the encoders. After adjustment of the center of the object gear using an r-θ stage with a micrometer head, the eccentricity decreased considerably from 262 μm to 12μm.

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The aim of this research is to achieve a real time motion error correction of an object guided by squeeze air films. They are generated through sinusoidal relative perpendicular motions between the object and the driving pads excited by piezoelectric actuators. The non-contact motion error correction can be realized by controlling piezo expansion according to the measured motion error of the object while keeping piezo oscillations. In this paper, theoretical considerations and experimental verifications for squeeze air film characteristics are presented. Lees' difference approximation method is applied to solve the Reynolds equations governing pressure distribution for the upper and lower side air film and the equation of object motion simultaneously. The experimental equipment has an object of which the radial motion is constrained by an aerostatic guide to make a free vertical motion. It was experimentally confirmed that the squeeze air film could suspend the object with the mass of 1.39kg. The influence of step between surfaces of the driving pad and a pressure sensor embedded in the pad was considered by numerical analysis. When the depth of sensor surface was less than 20μm, the drop of a time mean pressure at the center of the driving pad was 2% or less for the flat surface. The experimental results of the time mean air film pressure and the floating height of the object agreed well with the numerical ones within 5% error when only the lower exciter was driven. Furthermore, as the lower and upper exciters were driven, it was demonstrated that the proposed technique could expect the characteristics of squeeze air films.

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Extrusion is a typical production method of siding used as a board for surfacing the outside wall of a building. The raw material is first extruded and then a pattern is put on the surface by a pattern roller. The pre-hardened boards thus produced are subjected to irregular forces caused by speed differences among the roller and three stages of conveyers when the boards are transferred downstream from the pattern roller. These forces damage the appearance of siding and significantly reduce values of products. The speed differences must be kept to a minimum where each conveyer is synchronized to track the pattern roller speed. A preview control is developed in this paper for the tracking control because the pattern roller speed as reference input fluctuates considerably and the conveyers to be controlled have large time delays. It is clarified that 1) the pattern roller speed can be made predictable, 2) the speed variation has a particular frequency, 3) the conveyer's time delays can be compensated by feeding a future roller speed as a reference value to each conveyer, and 4) the reference value can be determined from a Bode diagram of the conveyer.

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An automatic focus detection system for microscopes using the stripe pattern projection method has been developed in this study. Although there are various methods that can be used in the automatic focus detection units of microscopes, the stripe pattern projection method is widely used because automatic focusing can be achieved even on a mirror or rough surface. In the conventional equipment with automatic focusing, the stripe pattern projection unit is set in the illumination unit, and the optical unit for focal position detection is set elsewhere. Therefore, the designer had to develop the automatic focus detection system, when the new equipment was developed. Size and cost reduction for the system are attempted by setting both the stripe pattern projection unit and the optical unit for focal position detection in the commercially available universal illumination unit. An automatic focus detection sensor used for a commercially available camera is adopted and a cylindrical lens is set in front of the sensor. The illuminance of the real image plane is increased and the detection time of the sensor is reduced by one-fifth. As a result of using the objective lens of 0.65 numerical aperture and 40× magnification, the automatic focusing accuracies of ±0.5μm and ±1.0μm have been achieved for samples with a mirror and rough surface, respectively.

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We have been developed a surface inspection system for ultra fine particles on a bare silicon wafer. The system combines scanning laser beam illumination technique with a cooled CCD detector and ultramicroscopic technique in a single instrument. In this system, the wafer is illuminated by blue-green light from an argon ion laser source (wave length : 488nm, power: 1.5W) at oblique incidence 76 degree. The scattering light from the particles on the wafer is detected with a 12-bit cooled CCD camera at the upper side of the wafer. Lower limit of detection is about 30 nm in particle diameter. The limit is determined by comparing the light scattering from particle and micro-roughness on the surface. The scattering light from particle and surface is brighter with p-polarization illumination than that with s-polarization illumination. The light scattering intensity of ultra fine particle is strongly dependent on the particle size, and it is proportional to the sixth power of the particle diameter.

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In this study, a resonance based touch trigger probe that detects a contact with lower measuring force is developed. The touch trigger probe is consisted of 2 parallel thin cross-shaped leaf springs and a piezoelectric actuator. The fundamental concepts and analysis by FEM are described. From the analysis, when the probe vibrates at the frequency of the 5th natural mode, the probe is considered to oscillate like an inverted pendulum with the center of oscillation being near the tip of the stylus. If a contact has been made when the probe is in the condition of natural vibration, the waveform is changed. Thus a contact can be detected by catching the change of waveform. A prototype is constructed and tested. According to the results of experiments, the measuring force is smaller than 50μN, and the repeatability could be smaller than 500 nm. Meanwhile, because the trajectory of the tip of the stylus remains still unknown, further analytic investigation is needed and it will lead to the optimum design.

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This report deals with the useful software program built for the previously developed automatic image processing system so that the characteristics of the wheel surface consisted of a great number of cutting edges beyond one thousand can be grasped more easily. The program is mainly realized by three kinds of utilities; a) the wheel surface viewer can display about 30 micro-scope images on CRT display at the same time in order to judge the condition of wear land of cutting edges at a glance, b) the cutting edge list can be used to estimate the change of cutting edges in the processes of truing, dressing and grinding, c) the cutting edge map can show visibly the position and the distribution of all the cutting edges on the whole wheel surface and clarify the difference of cutting edges before and after the processes. The new utilities are ascertained available in the experiment for following the behaviors of cutting edges in actually truing process.

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Carbon Nitride(C-N) films were formed on several engineering material substrates by ion-beam-assisted deposition(IBAD). Si(100) wafer, high-carbon chromium bearing steel(SUJ2), pure titanium(99.5 %), and aluminum alloy(A7075) were used as substrates. Nanoindentation hardness and tribological properties were investigated. The films on all substrates showed about 20 GPa of hardness and 200 GPa of elastic modules. There were no dependences on substrate materials in the synthesis of C-N films by IBAD technique. The friction coefficients were 0.2 irrespective of the substrate materials. Significant improvement of wear resistance was verified by forming C-N film on these substrate materials. Especially, the C-N film on titanium substrate showed excellent durability due to high adhesion strength. It could be concluded that the synthesis of C-N film by IBAD technique was a very effective surface modification method.

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High gain is necessary in order to realize high-speed feedback control of the linear motor. However, high gain setting is not generally possible as it causes resonance of the machine structure. In order to realize high gain while restraining resonance, a method has been devised with an observer, which includes a resonance model of the linear motor. The motion information of the linear motor moving element is used while disregarding vibration. The observer calculates motion of the center of gravity. Proposed method has been successfully experimented with an actual linear motor in that high gain feedback control and high speed positioning have been effectively demonstrated.

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