Shadow moiré method is useful to measure height distribution of a flat object with high accuracy because it can use a fine grating by setting the grating near the object. By combining with a phase shifting method, it is quantitatively analyzable with high accuracy. In this study, the authors propose a new phase-shifting shadow moiré method using light-source-stepping method with LED light sources. The phase-shifting can be performed at high speed by changing the electrical on/off switches of the LED light sources because of no use of movable parts. The accuracy is 3μm in a 90mmx90mm area. The theory and experimental results are shown.

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Operation properties of an optical system for elliptical beam generation is described in this report. The system is constructed by using commercially-available elements and consists of three parts of power variation, beam expander and elliptical beam formation. The power variation and elliptical beam formation are achieved by a computer-controlled system with high accuracy and repeatability. Experimental results of system characteristics showed that the focal line width at the focal point is the same as that of the diffraction limitation. The elliptical beam system can be applied to the laser dicing of the semiconductor wafer with a cutting width less than 20μm.

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In this study, tennis ball rotation and trajectory are analyzed quantitatively. Fourteen dots are marked on a tennis ball to detect the ball rotation, and the markers' x-y positions are detected from high-speed camera images. First, the 3-D positions of the markers are calculated. Then, the rotation matrix is calculated by using the 3-D marker positions of successive camera frames. The rotation parameters, roll, pitch, and yaw, are calculated from the rotation matrix. The 3-D trajectories of the ball center are calculated by the stereo method. The experimental results showed drastic change of ball rotation, velocity and course at bounce and shot frames.

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This paper presents a method of high-speed estimation for optical axes using image processing. The proposed method are planed to use in a ranging system, which estimate distances on the basis of triangulation by a monocular camera and a lamp. To define the centers of optical sources from shot images, Robust and high-speed estimation of distributions is needed because the light intensity distributions from lamps are deformed depending on the textures or other environmental factors. The optical axes are estimated on the basis of hypothesis that the diffused luminance distributions of the shot images from the camera have Gauss distributions. The proposed method uses binary codes in optical axes estimation to perform high-speed processing having robustness not affected by environmental variations.

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We propose a phase-controlled traveling-wave-type ultrasonic motor (USM) driven in the constant temperature mode. By setting the phase difference between two sinusoidal driving signals fed into USM zero, a thermally-equilibrium condition of USM is attained without rotation. We call such an operation mode idling. Because the resonance frequency of the USM depends on the temperature, the rotational speed is decreased with increasing the temperature, which has been made the frequency control of USM somewhat difficult. Unlike the conventional frequency-controlled USM, a phase-controlled one with idling is free from the temperature change and is controllable with ease. We have constructed a feedback loop system for the phase-controlled USM and evaluated its performance in comparison with the conventional frequency-controlled one.

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The shape and distribution of abrasive grains in the grinding wheel have a significant influence on the grinding performance. Therefore in order to realize the high-precision grinding process, it is essential to measure the shape and distribution of abrasives on wheel working surface. We have developed an on-machine 3D measurement system to study the surface topography of grinding wheel by binocular stereopsis without demounting the wheel from the grinding machine. In comparison to the results measured by the laser microscope, the developed system has been confirmed to have the accuracy of -5.6% in the horizontal direction and -3.4% in the vertical direction. Also, we analyzed the behavior and variation of individual grains by tracking observation of 3D topography of the grinding wheel working surface in the grinding process by using this system. As the result, the distribution and variation of abrasive grains including protrusion height, flat part length, half-tip angle, grain density and effective cutting edge density are able to be quantitatively evaluated.

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Manganese Zinc ferrite single crystals have been widely used for making video cassette recorder (VCR) heads. The initial permeability is one index relating to the performance of magnetic heads. It was known that the initial permeability of the crystals decreased as a function of residual stresses left after machining of the magnetic heads. At that time, most of the crystals were grown in the Bridgman furnace, so that compositional segregation could not be avoided and no research work was systematically carried out on the relationship between anisotropic stress effects and initial permeability of the crystals. For the tensile and compressive samples we used very uniform single crystals of less than 0.1mol% compositional segregation, produced by solid phase reaction. The variously orientated crystal samples, shaped like picture frames, were cut by ultrasonic machining and etched more than 20μm deep by a heat phosphoric acid to remove residual stresses. The initial permeability was measured during tensile and compressive tests as a parameter of frequency from 100kHz to 100MHz, in a temperature-controlled silicon oil bath. The initial permeability of the crystal samples under uniaxial stress was also obtained theoretically by the magnetocrystalline anisotropy energy due to the rotation magnetization. It was found that the initial permeability at 50MHz might be improved by more than 10dB by applying the tensile stress of 25MPa at <100> direction. This phenomenon may be applied to other applications.

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We have attempted to improve performance of cutting tools by coating on tool edge surface with a hard and lubricious thin film. In this work, B-C coatings have been prepared on silicon and tungsten carbide substrates by DC magnetron sputtering with a sintered B₄C target. For obtaining excellent frictional properties in the B-C coatings, CH₄ gas was introduced as a plasma gas Nano-indentation studies showed that the CH₄ introduction in the film formation process led to a lower hardness of the film. On the other hand, the adhesive strength to the substrate was increased by the CH₄ introduction in the film formation process. Furthermore, the frictional properties of the B-C coating against a steel ball in an ambient atmosphere were improved by CH₄ addition and their friction coefficients reduced from 1.0 to 0.4. Then, we created B-C coated tools, and evaluated the cutting performance against a stainless steel by using a high speed precision lathe. The B-C coated tool showed better cutting performance than non coated tool. However, the B-C coating was peeled off from the tool edge at the cutting length of 1000 m in a dry condition.

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