In a future system of EUV (extreme ultraviolet) lithography, a high power light source with 13.5nm wavelength is demanded for long operation life time under high repetition rate. Tin target has significant potential for high conversion efficiency. This paper presents a new method to develop a debris-free EUV light source by using tin targets with conical and cylindrical through-holes, which have advantages for increasing EUV emission and reducing debris in the direction of the through-hole exit. The strong EUV intensity from plasma produced by Q-switched Nd:YAG SHG (second harmonic generation) laser is measured with a detector, that consists of Mo/Si deposited photodiode, Zr filter and Au mirror. For commercial EUV light source, repetitive use of the target is required. The emission stability for repeated operation is evaluated using these through-hole targets. Also, the visible light emission from the confined plasma in the through-hole is observed using a high-speed camera, and then the laser ablation process is considered. Finally the feasibility of the tin target with cylindrical through-hole is discussed for development of commercial EUV lithography system.

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It is necessary to manage not only in-process but also pre-process and post-process for improvement of the welding quality. In this paper, the fault condition sensing technique is proposed by the waveform monitoring and the waveform analysis of the physical quantity in the welding process. The waveform monitoring is applying control chart method in quality control. The waveform analysis such as running average process, differential characteristics, integral characteristics and time subtraction of data are particularly effective for monitoring a laser welding system. Application of the technique to the laser-half-penetration-spot-welding for thin stainless steel sheets is discussed. This monitoring system was verified by the welding examination with pulse gating mode Nd:YAG laser welding system. Welding conditions as follows; peak power is 4kW, pulse width is 30ms, processing speed is 1.5m/min, and assist gas is Argon. These successful results were very promising.

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The cutting performance of some coated carbide tools in hardmilling of hardened steel is investigated. The cutting characteristics are mainly evaluated by tool wear and temperature at flank face for four types of coating films on two types of base materials. Cutting force and surface roughness are also examined. The temperature of cutting tool is measured using a two-color pyrometer with an optical fiber. The tool flank wear becomes large in the case of TiN and TiCN coated tools. The tool flank temperature increases with the increase of surface roughness of coated film, and reaches approximately 500°C for TiAlN/ AlCrN coated tool. On the other hand, the cutting forces do not change so much with surface roughness of coated film. In the case of P30-grade cemented carbide as base material, tool flank wear and flank temperature become large compared with K10- grade. The surface roughness of workpiece increases with the increase in tool flank temperature more than approximately 530°C.

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The paper presents an analytical method to predict critical cutting conditions for regenerative chatter vibration in ball end milling process. The ball end milling is an important precision machining process, which is used in production of impellers, screw propellers and turbine blades with free-form surfaces. As these thin structures are flexible, the regenerative chatter vibration often occurs and causes severe problems such as short tool life and deterioration of surface quality. Therefore, an analytical model is developed with consideration of tool inclination around cutting feed direction, and it is applied to predict the stability limits at varied inclination angle in the present research. The ball end milling experiments are also conducted at various inclination angles to verify the developed analytical model. It is confirmed that the critical depths of cut predicted by the developed model agree qualitatively with experimental results at various tool inclination angles. Both the analytical and experimental results show that the critical depth can be increased considerably by the tool inclination around the cutting feed direction, and thus it is expected that the developed model will be useful to optimize tool path, inclination and other machining conditions for highly-efficient ball end milling of the flexible workpieces.

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In actual aerostatic spindles, it is said that manufacturing the squareness of a thrust collar within the accuracy of 1 μm is very difficult. Furthermore, it is naturally considered that the squareness error of the thrust collar affects the rotational accuracy of aerostatic spindles. Therefore, in this paper the rotational accuracy of an aerostatic spindle with the squareness error of a thrust collar is numerically investigated. In addition, the effects of the axial bearing stiffness on rotational accuracy of a spindle are discussed by treating two types of aerostatic thrust bearings with different. The spindle locus was obtained by using Non-Linear Orbit Method in which the Reynolds equation and the equation of motion of a spindle were simultaneously solved. It was found that the squareness error of the thrust collar greatly affects both radial and axial displacements of the spindle at speeds.

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This paper deals with production of micro polycrystalline diamond (PCD) drill by wire electrical discharge machining and drilling to quartz glass with 0.3mm diameter PCD drill. In the production test the relation between electric conditions of wire-EDM to PCD and surface roughness and edge quality of PCD drill was shown. In the drilling test, tool wear, generated chips, chipping at hole entrance and inner surface of holes were investigated. As a result, it was found that roughness of PCD by wire-EDM is governed by uneven distribution of Co and electric current and that voltages less than 60V cause the unstable machining condition.

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A slide screw drive is a kind of old technology. However it is usable and important technology even in high-tech fields such as semiconductor manufacturing. This paper intends to improve the slide screw controllability which has strong non-linearity due to grease characteristics. We measured the grease non-linear viscosity using a special tool. This grease property explains the shot dislocation phenomenon which occurs in slide screw stages particularly. Since we understood the phenomenon, we found one non-linear gain control method which embedded the grease property reversely. It not only fixed the dislocation problem but also enhanced the slid screw stage performance and maintainability.

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Projector-camera systems are utilized for getting range data easily. But it needs comlicated calibration. This paper presents a process of calibration for the projector-camera system. First, a fundamental matrix is calculated with the use of projected points on a standard cube surface from the projector. The fundamental matrix is applied to define the projection matricies of the projector and camera that include intrinsic and extrinsic parameters. Three dimensional cooridnates of projected points on the standard cube are reconstructed by projective reconstruction method using the projection matrices, and surfaces of the standard cube are computed with the use of these points in a projection space. And vertices of the standard cube are computed as intersection points of the cube surfaces in the projection space. Finally, projective transformation between the projection space and the world coordinate system is calclated by these vertices. Then intrinsic and extrinsic parameters of the projector-camera system are determined by the proposed calibration method.

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The study deals with automatic path planning method for cutting operation using an industrial robot. In general, studies of motion planning for industrial robots are divided in two approaches, considering a robot configuration or a tool configuration. However, in case of cutting operation using an ultrasonic cutter, generation of optimal tool path becomes difficult, because it is required consideration of continuous tool posture, wide movable range of robot, and high tool feed speed. In this study, we propose the use of an original local configuration space that generated by two angles that determine tool posture at each cutting point, and generate tool path using an A-star search algorism based on the evaluations of interference, movable range and mobility of robot that varied according to relationship of tool feed speed and angular speed of each joint. As a result, it is found that the proposed path generation method is more effective than conventional methods.

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The extremities of both humans and animals have a muscle coordinate system. This muscle coordinate system consists of three pairs of antagonistic muscles, one antagonistic pair of bi-articular muscles, and two antagonistic pairs of mono-articular muscles. Motion control, using a muscle coordinate system, has been confirmed using robotics, and verified using a robotic arm equipped with three pairs of antagonistic actuators. In a two-joint link model, equipped with a muscle coordinate system, the moment arms and elastic coefficient of the bi-articular actuators and the mono-articular actuators at the first joint contribute to both the control of the elastic ellipse and the trajectory exerted at the endpoint. The present study investigates the use of a twojoint link mechanism, based on the human muscle coordinate system, to complete contact tasks. The mechanical properties of the muscle coordinate system were examined both theoretically and experimentally in terms of robotics, and the results demonstrate that a robotic arm provided with these mechanical properties could resolve a contact task in both the active condition and the passive condition.

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In the factory automation market, size reduction of parts has rapidly been accelerated, and the demand for downsizing of motors will be increased. We developed an ultra compact optical angle sensor for the ultra compact servomotor. The size of scale disk in this sensor is φ11mm.

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This paper presents a new scheme for construction of a piecewise G² surface which interpolates a rectangular curvature continuous quintic Bezier curve mesh. For application to practical CAD/CAM, a parametric surface with a controlled curvature distribution can be generated based on a discrete surface with a smooth curvature distribution. First, a discrete surface is constructed by minimizing an integral of square of the 2nd derivative of principal curvatures. The discrete surfaces have good curvature distributions, because they have a high degree of freedom. A G² quintic Bezier curve mesh is constructed by curves that minimize an arc length integral of square of the 2nd arc length derivative of curvature binormal, based on the discrete surface. After estimating twist and cross-boundary derivatives from geometric properties of the discrete surface, a G² surface interpolates the curve network by minimizing an energy function that measures the variation of principal curvatures. The generated surface elements are bi-quintic Gregory patches.

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A variety of scenarios including the IPCC's Emissions Scenarios have been described toward achieving the sustainable society. Describing such scenarios is a hopeful approach for drawing future images of sustainable manufacturing. However, there exist difficulties in understanding these scenarios rationally since their logical structure is ambiguous. This prevents us from relying on these scenarios and describing new scenarios by using existing scenarios. In order to support understanding, analyzing, and describing scenarios, this paper proposes the concept of Sustainable Society Scenario Simulator (3S Simulator). As the first step, this paper proposes a method for describing scenarios structurally for a rational understanding of scenarios. This method expresses a scenario in four levels; i.e., Scenario, Expression, Word, and Data Levels. Particularly, this paper focuses on Scenario and Expression Levels and formulates the “base” of a scenario to clarify rationales that logically support its conclusions. The results of a case study involving World Energy Outlook 2004 showed that the proposed method successfully clarifies the logical structure of the scenario and identifies its base of the rationale. In this scenario, it was revealed that many of conclusions are derived beyond logicality since the scenario inevitably contains future predictions.

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