This paper presents a robust optical disc discrimination method which tolerates pick-up head and laser power source deviations. Unlike the prior art techniques, the proposed method uses normalization process to cancel influences caused by deviations of pick-up heads and laser power source so as to minimize the disc discrimination error rate to secure normal disc playback function of an optical disc drive.

We have proposed a brand-new noninvasive ultrasonic sensor for measuring muscle activities named as Ultrasonic Muscle Activity Sensor (UMS). In the previous paper, the authors achieved to accurately estimate joint torque by using UMS and electromyogram (EMG) which is one of the most popular sensors. This paper aims to realize to measure not only joint torque also joint angle by using UMS and EMG. In order to estimate torque and angle of a knee joint, muscle activities of quadriceps femoris and biceps femoris were measured by both UMS and EMG. These targeted muscles are related to contraction and extension of knee joint. Simultaneously, actual torque on the knee joint caused by these muscles was measured by using torque sensor. The knee joint angle was fixed by torque sensor in the experiment, therefore the measurement was in isometric state. In the result, we found that the estimated torque and angle have high correlation coefficient to actual torque and angle. This means that the sensor can be used for angle estimation as well torque estimation. Therefore, it is shown that the combined use of UMS and EMG is effective to torque and angle estimation.

In order to realize high accuracy and high speed for measuring the surface profile of soft thin film such as photo resist materials for semiconductor process, we proposed the method of using a multi-ball-cantilever AFM, which has more than one cantilever for wide area and high speed in measurement and each cantilever has the ball stylus with diameter to avoid the plastic deformation of measured surfaces. Therefore, in this research, we investigated the profiles of resist material and influence of the AFM stylus on the resist surface. Then, to verify the feasibility of this method, we performed the computer simulation that reflects the relationship between the shape, size and load of the indenter and the deformation of resist surface with FEM (Finite Element Method), and discussed the influence from the force-displacement curve. The fundamental experiments were carried out using the multi-ball-cantilever AFM and we confirmed the feasibility for measuring the surface of soft thin film with high speed.

We have developed a functional distributed fiber-optic stress sensor by synthesis of the optical coherence function (SOCF). The technique determines the location of stress-induced polarization mode coupling in a polarizationmaintaining fiber (PMF) by measuring the optical path difference (OPD) between the fast mode and the slow mode in PMF with SOCF. By modulating the frequency of the lightwave from a super-structure-grating distributed Bragg reflector laser diode (SSG-DBR-LD) in a stepwise waveform, the coherence function is synthesized into a series of periodical peaks in the meaning of time-integration. The period is controlled to allow only one coherence peak enter the range of the PM fiber under test. Then we can measure the polarization mode coupling at the position corresponding to the peak. The position of the peak is adjusted by using a phase modulation proportional to the frequency modulation. Therefore, polarization mode coupling distribution along the fiber can be obtained. Up to date, one end of the sensing fiber is used as the input end, and the other as the output end. This scheme is generally not convenient for remote applications. In this presentation, we report two new effective methods that unify the input and the output to one end of the fiber. In one scheme, a mirror plus a polarizer is attached to the far end of the PM fiber. The other scheme employs a polarization beam splitter (PBS) attached to the far end of the PM fiber. The light beam output from the PBS in one polarization direction is fed back into the fiber through the PBS in the perpendicular polarization direction. Experimental demonstrations for both schemes are presented.

In order to measure a surface roughness profile without contacting with surface, optical equipments are usually used. However, the light interference based measurements require a translation mechanism of nano-meter order to make phase differences or multiple focusing. That is an obstacle for the optical measurement to be applied to in-process measurement for factory automation. On the other hand the light reflectance based method do not need any moving mechanism. However, it has been known that it can measure only an average surface roughness but measure surface height profile. In this research, a new algorism is proposed to estimate a microscope surface profile from a given reflected light intensity image. The principle of the algorithm is based on statistical parameterizations of decomposed light. The proposed algorithm was proved to well estimate surface height profiles through some equipments.

New confocal microscopy having no mechanical beam scanning devices is proposed. The proposed system can get two-dimensional information of a specimen in real-time by using spectral encoding technique and slit aperture. Spectral encoding technique is used to encode one- dimensional lateral information of the specimen in wavelength by a diffraction grating and a broadband light source. The modeling of the optical system is conducted. The effect of slit width variation on the axial response of the system is evaluated by numerical simulation based on the wave optics. Proper width of the slit aperture which plays a crucial role of the out-of-focus blur rejection is determined by a compromise between axial resolution and signal intensity from the simulation result. Design variables and governing equations of the system are derived on the assumption of a lateral sampling resolution of 50 nm. The system is designed to have a mapping error less than the half pixel size, to be diffraction-limited and to have the maximum illumination efficiency. The designed system has a FOV of 12.8 μm x 9.6 μm, a theoretical axial FWHM of 1.1 μm and a lateral magnification of -367.8.

In this paper, the feasibility of a glass-based guided-wave optical microphone is described. The optical microphone consists of a rectangular diaphragm and a straight waveguide on the diaphragm. The sensitivity of the microphone and the resonance frequency of the diaphragm are dependent on the diaphragm dimensions. In this study, to confirm operation of the proposed optical microphone, the target values for phase sensitivity and resonance frequency were set at 1.3 mrad/Pa and 5 kHz, respectively. By design considerations, the diaphragm dimensions were determined to be 16 mm × 16 mm × 0.15 mm. After fabrication, a sound wave of 1 kHz and 25 Pa, corresponding to 122 dB-SPL (sound pressure level), was applied to the microphone. In the experiment, the intensity-modulated output with the same frequency as the applied sound wave was obtained, but the observed output was unexpectedly caused by misalignment of the optical components due to mechanical vibration. The estimated output signal by the normal operation of the microphone for a sound pressure of 25 Pa was 1/10 - 1/100 of the noise level, according to the measured output characteristic to static pressure. In order to detect normal speech ranging from 55 to 65 dB-SPL, the S/N ratio should be improved by a factor of more than 10⁴.

A method for testing distributed amplifiers is presented; the multipath interference (MPI) is detected as a beat spectrum between the multipath signal and the direct signal using a binary frequency shifted keying (FSK) test signal. The lightwave source is composed of a DFB-LD that is directly modulated by a pulse stream passing through an equalizer, and emits the FSK signal of the frequency deviation of about 430MHz at repetition rate of 80-100 kHz. The receiver consists of a photo-diode and an electrical spectrum analyzer (ESA). The base-band power spectrum peak appeared at the frequency of the FSK frequency deviation can be converted to amount of MPI using a calibration chart. The test method has improved the minimum detectable MPI as low as -70 dB, compared to that of -50 dB of the conventional test method. The detailed design and performance of the proposed method are discussed, including the MPI simulator for calibration procedure, computer simulations for evaluating the error caused by the FSK repetition rate and the fiber length under test and experiments on singlemode fibers and distributed Raman amplifier.

To realize high productivity and reliability of the semiconductor, patterned wafers inspection technology to maintain high yield becomes essential in modern semiconductor manufacturing processes. As circuit feature is scaled below 100nm, the conventional imaging and light scattering methods are impossible to apply to the patterned wafers inspection technique, because of diffraction limit and lower S/N ratio. So, we propose a new particle detection method using annular evanescent light illumination. In this method, a converging annular light used as a light source is incident on a micro-hemispherical lens. When the converging angle is larger than critical angle, annular evanescent light is generated under the bottom surface of the hemispherical lens. Evanescent light is localized near by the bottom surface and decays exponentially away from the bottom surface. So, the evanescent light selectively illuminates the particles on the patterned wafer surface, because it can't illuminate the patterned wafer surface. The proposed method evaluates particles on a patterned wafer surface by detecting scattered evanescent light distribution from particles. To analyze the fundamental characteristics of the proposed method, the computer simulation was performed using FDTD method. The simulation results show that the proposed method is effective for detecting 100nm size particle on patterned wafer of 100nm lines and spaces, particularly under the condition that the evanescent light illumination with p-polarization and parallel incident to the line orientation. Finally, the experiment results suggest that 220nm size particle on patterned wafer of about 200nm lines and spaces can be detected.

We propose the spectroscopy-tomography of single cells to improve the early detection and treatment of cancer. This technology can obtain the 3-dimensional distribution of components at a high spatial resolution. In this paper, we mention the analysis result of the cross-sectional images of the microsphere whose diameter is 10 μm. The distribution of the internal submicron-defect in the microsphere can be analyzed. To obtain the correct 3-dimensional absorption distribution, the axial runout can not be allowed. However, the center of rotation is displaced because the cells have complex refractive index distribution. Therefore we propose the image processing that uses the normalized correlation function as estimated value. The cross-sectional image of the microsphere is improved and the vague internal defect becomes to be distinguished by this proposed method. Moreover, based on this method, the 3-dimentional refractive index distribution in a single cell is estimated and the part which has a high refractive index in the cell is distinguished clearly. And we mention the proposed variable phase-contrast spectrometry as the 2-dimensional high spatial resolution spectrometry. This proposed method is a phase-shift interferometry between the 0th order diffracted light and the higher order diffracted light. We discuss the experimental results of the spectral characteristics using the proposed variable phase-contrast spectrometry. We measured the spectral characteristics at each pixel using the color filter of the liquid crystal and verified that the 2-dimensional spectral characteristics can be measured with good result.

Counterfeiting a finger will become an important issue for unattended fingerprint identification. To fight against this threat, we have proposed to look at the color changes in a deformed finger during an input action. When a finger is pressed upon an optical fingerprint sensor, it is gradually deformed and the color of the fingerprint images changes. This is due to the blood movements inside the finger. If the extent of this color change exceeds a certain threshold, we judge that the finger is alive. In this paper, we report on the spectral changes of the light scattered by a deformed finger first. As the pressure applied to the finger increases, the relative intensity of the red portion of the spectrum decreases. Even after the pressure is off, it takes some time for this intensity to recover to its original value. Second, we discuss a dual-LED imaging system based on scattered light detection. Here, red and green-emitting LEDs are mounted on an edge of a plastic plate which serves as a light-guide. The light scattered by a finger placed on this light-guide is captured by a standard color camera. Based on the experiments conducted on several types of replicas as well as 42 volunteers, we show that this system is capable of identifying the live fingers. Signal extraction process is investigated for stable separation between live fingers and replicas. A model based on the blood movement inside a finger is developed. A mobility-index is proposed and is correlated with the ages of the volunteers participated in this study.

Semiconductor design rules and process windows continue to shrink, so we face many challenges in developing new processes such as 300mm wafer, copper line and low-k dielectrics. The challenges have become more difficult because we must solve problems on patterned and un-patterned wafers. The problems include physical defects, electrical defects, and even macro defects, which can ruin an entire wafer rather than just a die. The optics and electron beam have been mainly used for detecting of the critical defects, but both technologies have disadvantages. The optical inspection is generally not enough sensitive for defects at 100nm geometries and below, while the SEM inspection has low throughput because it takes long time in preparing a vacuum and scanning 300mm. In order to find a solution to these problems, we propose the novel optical inspecting method for the critical defects using standing wave shift. This method is based on a super-resolution algorism in which the inspection system's resolution exceeds the diffraction limit by shifting standing wave with the piezoelectric actuator. Additionally this method is optical one, so we can expect to develop high throughput inspection system. In this report, we performed theoretical discussions and computer simulations the defect detection on a patterned wafer. As a result, we succeeded in detecting the critical defects in the sub-90nm line and space interconnections.

In phase-shifting digital holographic interferometry for measuring a displacement distribution of an object, holograms and reconstructed images have speckle noise and they provide large error in the calculation of displacement analysis. In order to decrease the effect of speckle noise, we previously proposed a new method using windowed holograms. In this paper, we propose a new averaging method of the obtained phase-difference values. Many phase-difference values at a point obtained by different windows for a hologram are averaged by considering the weight for each phase value. The weight is changed as the m-th power of the absolute amplitude of the complex amplitude of the reconstructed object. As the result, when the number n of the windowed holograms becomes larger, the standard deviation of the error becomes smaller. When the power m is 2, the error becomes the minimum. The standard deviation of the errors in the case of a flat plate with 316 nano-meter out-of-plane displacement is 88 pico-meter when n=1024 and m=2.

This paper describes a method of measuring the shape of solder bumps arrayed on an LSI package board presented for inspection based on the shape-from-focus technique. We used a copper-alloy mirror deformed by a piezoelectric actuator as a varifocal mirror to build a simple yet fast focusing-mechanism. The varifocal mirror was situated at the focal point of the image-taking lens in image space so that lateral magnification was constant during focusing and orthographic projection was perfectly established. A focused plane could be shifted along the optical axis with a precision of 1.4 μm in a depth range of 1.5 mm by driving the varifocal mirror. A magnification of 1.97 was maintained during focusing. Evaluating the curvature of field and removing its effect from the depth data reduced errors. The shape of 208 solder bumps 260-μm high arrayed at a pitch of 500 μm on the board was measured. The entire 10 mm x 10 mm board was segmented into 3 x 4 partly overlapping sections. We captured 101 images in each section with a high-resolution camera at different focal points at 15-μm intervals. The shape of almost the entire upper-hemisphere of a solder bump could be measured. Errors in measuring the bump heights were less than 12 μm.

Non-contacting shape measurement for 3-D objects is important in automated manufacturing, quality control of components, 3-D solid modeling, etc. Optical measurement of omnidirectional shape has been done by rotating an object and/or measuring it from different directions. We previously proposed a phase-shifting method using Fourier transform (PSM/FT) and a multi-reference-planes method (MRPM) to obtain geometric parameters without influence of lens distortions. Both a measured object and a reference object are simultaneously measured from different directions. All partial point-clouds can be merged into one global coordinate system by a transform matrix calculated from the reference column on a rotary stage. 360-deg 3-D shape can be measured using the above method. In the PSM/FT, since the initial phase information is determined from only the first frequency of the Fourier spectrum of the phase-shifted intensity values at each point of an object and the frequency components higher than the first frequency almost depend on noise, almost experimental noise can eliminated. The phase reliability evaluation value using Fourier transform (PREV/FT) is, therefore, defined as the ratio of the first frequency component of the Fourier spectrum to the average of the frequency components higher then the first frequency of the Fourier spectrum. The PREV/FT is useful to merge data when measurement conditions are changed. In this paper, we propose a method that all partial data can be merged into global coordinates using the PREV/FT on overlapped areas and omnidirectional shape measurement is achieved.

Traditional sinusoidal phase-shifting algorithms involve the calculation of an arctangent function to obtain the phase, which results in slow measurement speed. This paper presents a novel high-speed two-step triangular phase-shifting approach for 3-D object measurement. In the proposed method, a triangular gray-level-coded pattern is used for the projection. Only two triangular patterns, which are phase-shifted by 180 degrees or half of the pitch, are needed to reconstruct the 3-D object. A triangular-shape intensity-ratio distribution is obtained by calculation of the two captured triangular patterns. Removing the triangular shape of the intensity ratio over each pattern pitch generates a wrapped intensity-ratio distribution. The unwrapped intensity-ratio distribution is obtained by removing the discontinuity of the wrapped image with a modified unwrapping method commonly used in the sinusoidal phase-shifting method. An intensity ratio-to-height conversion algorithm, which is based on the traditional phase-to-height conversion algorithm in the sinusoidal phase-shifting method, is used to reconstruct the 3-D surface coordinates of the object. Compared with the sinusoidal and trapezoidal phase shifting methods, the processing speed is faster with similar resolution. This method therefore has the potential for real-time 3-D object measurement. This has applications in inspection tasks, mobile-robot navigation and 3-D surface modeling.

We demonstrate a real time 3D position sensing of multiple light sources by capturing their ring images that are transformed by the molecular lens system with large spherical aberration. The ring images change in diameter in accordance with the distance to the light sources, and the ring center positions determine the directions toward them. Therefore, the 3D positions of light sources are calculated by detecting the diameters and center positions of the circles. This time we succeeded to measure 3D positions of multiple light sources simultaneously in real time by extracting and tracking the circle patterns individually. Each circle is extracted by the Hough transform technique that uses not-closely-distributing three edge points to search the primal votes more than threshold, and is tracked by predicting the successive positions by Kalman filter. These processes make it possible to measure the 3D positions of light sources even in the case of overlapped plural circles. In the experiment, we could track several circle patterns measuring the center positions and diameters, namely, measuring the 3D positions of LEDs in real space. Measurement error of 3D positions for a LED was 6.8mm in average for 150 sampling points ranging from 450mm to 950mm in distance.

DMD (Digital Micro-mirror Device) is a new device, which has hundreds of thousands of micro-mirrors in one chip. This paper presents results of the development of a camera system based on DMD technology for phase analysis and shape measurement that we call "DMD reflection-type CCD camera" or "DMD camera". Incorporation of DMD technology enables accurate control of the intensity reaching the imaging detector of a camera. In order to perform accurate pixel-to-pixel correspondence adjustment with high accuracy, we use a moire technique. In addition, we introduce a high-speed controllable DMD operation board and improve the software to control each DMD mirror with high-speed. As the results, each DMD mirror works as a high-speed controllable shutter for the corresponding CCD pixel. Furthermore, as an application using the DMD camera, we perform an experiment by "DMD-type integrated phase-shifting method using correlations," which can analyze the phase distributions of projected grating from one image taken by the DMD camera. These principles and experimental results in dynamic condition are shown.

This paper proposes a sensor system for mobile robot for rough terrain. Our sensor system consists of 2 active joints and 1 distance measuring sensor. This distance measuring sensor is general purpose type distance measuring sensors which consist of PSD (Position Sensitive Detector) and infrared emitting diode and signal processing circuit. The main superior points are as follows: 1) this system is compact and light weight for enough attaching to small mobile robot, 2) It is very simple structure; which enables to do easy maintenance, 3) Since the sensor is attached to the robot, the sensor system should make full use of robot's degree of freedom (DOF), namely that's an active sensing. This paper explains the system structure of the proposed sensor system, and basic experimental result to confirm performance of this system.

Nowadays a major research issue of mobile robots is to develop a robust 3D environment sensing for navigation and task execution. To achieve this, a variety of techniques have been developed for the determination of the 3D scene geometric information such as stereo vision, laser structured light, laser range finder and so on. But these methods have many limitations. To overcome these limitations we introduce a new sensing algorithm, which is based on the moire technique and stereo vision. To verify the performance of this sensor system we conducted a series of simulation for various simple environments. The result shows the feasibility of successful perception with several environments.

Biogenic measurement has been studied as a robot's interface. We have studied the wearable sensor suit as a robot's interface. Some kinds of sensor disks are embedded the sensor suit to the wet suit-like material. The sensor suit measures a wearing person's joint, and muscular activity. In this report, we aim to establish an auto-calibration system for measuring joint torques by using EMG sensors based on neural network and sensor disks of a lattice. The Torque presumption was performed using the share neural network, which learned the data that formed the whole subject's teacher data. Additional training of the share neural network was carried out using the individual teaching data. As a result, that was able to do the neural network training in short time, high probability and high accuracy to training of initial neural network. Moreover, high-presumed accuracy was able to be acquired by this method Next, Sensor disks of a lattice was developed. EMG is measurable, checking the state of an electrode by that can measure biogenic impedance. That was able to measure EMG by sensor disks which has low impedance We measured EMG and joint torque by trial production sensor suit and torque measuring instrument. The predominancy of the torque presumption using the share neural network was check. We proposed Measurement system, which consists sensor disk of lattice. Experimental results show the proposed method is effective for the auto-calibration.

In the article, a new idea has been brought out to study a traditional optical question, that is, fiber sensor was taken accounted as an information system, which has been analyzed with the information theory. The author began the analyses with the structure of the fiber sensor's core, i.e. microbend modulator, and then evaluated its performance with the amount and strengthens of the impossible acquired information. The infection of the modulator's characteristics has been discussed from the view of information theory, which has been proven by theoretically deducing and experimental data. As the result, the author advanced the opinion that method based on optics information theory can guide the process of the performance optimizing and the parameters designing.

We propose the application of nitroanisole as a two-dimensional detector for infrared (IR) phase-shifting interferometry. The nitroanisole that is utilized in our experiment is liquid at room temperature and it has significant thermal lens effect, i.e. the refractive index for visible light is dependent on temperature. In addition, we verified by infrared absorption spectroscopy that the nitroanisole has an absorption band around 10.6μm in the IR region. Therefore, the interference fringe pattern that is generated on the nitroanisole by the IR beams may be treated as a phase grating for visible light. A Fresnel diffraction pattern made by visible laser light that is transmitted through the phase grating, i.e. the nitroanisole, can be observed as a superposition of the intensities corresponding to the profile of the phase grating and its harmonic components. Additionally, in response to a shift of the interference fringe on the nitroanisole, the Fresnel diffraction pattern on the observation plane also shifts by an equal amount. Utilizing this characteristic of nitroanisole, we attempted to estimate the IR phase map by applying the phase-shifting method to the diffraction patterns. We conducted an experiment aimed to measure the angle of a wedge of ZnSe, which is an IR transmitting material, and we confirmed the feasibility of obtaining phase measurements in the IR region by this procedure.

The spaceborne telescope assembly, which incorporates the primary mirror and secondary mirrors, baseplate, and metering structure, must retain the alignment after launch and during operation in space. A trend in spaceborne telescopes has been an increase in collection area and in resolution. Both of these demands in performance require larger primary mirror aperture sizes. Since the primary mirror often dominates the mass budget of the telescope, either of these options imply larger mass for the overall system. Technologies that enable lighter primary mirror will enable lower mass telescopes with larger apertures to reduce the launch costs of these missions. Primary mirror has much to gain from a significant reduction in areal density. Areal density is often limited by the stiffness to weight ratio of the primary mirror. Two key factors drive these criteria: telescope strucural characteristics and fabrication requirements. Major efforts in spaceborne telescopes have inspired research in lightweight optics. Also, metering strucure requires high stiffness, high dimensional stability and minimum obstruction of the telescope aperture to get high quality images. This paper describes a conceptual design trade studies that explores the structural views for the lightweight primary mirror as well as the metering structure in sub-metric class spaceborne telescope.

An integrated and automated measurement system of the static extinction ratio of crystal, the static or dynamic extinction ratio and half wave voltage of electro-optic crystal and the phase retardation of a wave plate is studied. By using the interferometric technology of polarized light, the pulse-modulated light source, the demodulation circuit and the division routine in computer program, the system effectively combines optics, mechanics and electronics technologies with computer control technology, which can be used to measure the above-mentioned three parameters fast, synthetically and automatically not only for laboratory research but also for product line. The results prove that with the measurement theory and the method of the paper, the extinction ratio of crystal can be measured to 10^-6 , and the repeat accuracy of the phase retardation of a wave plate can be measured to excel 0.3° ; moreover, by using the longitudinal modulation technology of the electro-optic crystal, the half-wave voltage of crystal can be measured accurately.

Making a map by using global sensor information is a mainstream tool in a mobile robot's navigation. It requires specific vision system such as a CCD camera, range finding system, and many other things. A laser range finder has highly collimated beams that can be obtained easily, thus achieving high lateral resolution, and the short wavelengths involved cause the light to be backscattered, rather than reflected by the target. For signal processing, the phase difference method using frequency modulation/demodulation is addressed in this paper. We used a diffused reflected beam to detect the phase shift in this system. But this beam has a minute signal and can be easily buried in nose. A modulation/demodulation method is used to measure the signals which are buried in noise.

The optical sensor is a measurement sensor that is widely used to measure the 3-D shape profile of object surface as a non-contact type. However, because the operating range of the sensor should be wide to measure the shape of objects that have lots of variation of a slope or bend, the accuracy of height measurement gets weak. If the surface of objects has a lot of variation of slope or bends, the gain of the optical sensor is varied according to the slope. Because height information obtained with the constant gain is incorrect information, it should be compensated without a large error. In order to improve performance measurement for this reason, if the method of scanning the object surface along the x and y directions using a gap control between the optical laser displacement sensor and object surface is applied, the nonlinearity could decrease. Moreover, compared with the method of maintaining the constant height of the sensor, the method of the gap control could reduce the measurement range of the sensor, so that the accuracy of height measurement for the sensor increases. In addition, the accurate information of shape measurement can be obtained, because the error caused by the slope or bend on the object surface can be reduced. Therefore, 3-D shape profile measurement using the method of constant gap control between the optical laser sensor and object surface shows better performance rather than the method of maintaining the fixed height of the sensor from the bottom.

This study aims to realize a motion capture for measuring 3D human motions by using single camera. Although motion capture by using multiple cameras is widely used in sports field, medical field, engineering field and so on, optical motion capture method with one camera is not established. In this paper, the authors achieved a 3D motion capture by using one camera, named as Mono-MoCap (MMC), on the basis of two calibration methods and triangle markers which each length of side is given. The camera calibration methods made 3D coordinates transformation parameter and a lens distortion parameter with Modified DLT method. The triangle markers enabled to calculate a coordinate value of a depth direction on a camera coordinate. Experiments of 3D position measurement by using the MMC on a measurement space of cubic 2 m on each side show an average error of measurement of a center of gravity of a triangle marker was less than 2 mm. As compared with conventional motion capture method by using multiple cameras, the MMC has enough accuracy for 3D measurement. Also, by putting a triangle marker on each human joint, the MMC was able to capture a walking motion, a standing-up motion and a bending and stretching motion. In addition, a method using a triangle marker together with conventional spherical markers was proposed. Finally, a method to estimate a position of a marker by measuring the velocity of the marker was proposed in order to improve the accuracy of MMC.

The paper proposes an evaluation technique for the elastic modulus of a cantilever beam by vibration analysis based on time average electronic speckle pattern interferometry (TA-ESPI) and Euler-Bernoulli equation. General approaches for the measurement of elastic modulus of a thin film are the Nano indentation test, Buldge test, Micro-tensile test, and so on. They each have strength and weakness in the preparation of the test specimen and the analysis of experimental results. ESPI is a type of laser speckle interferometry technique offering non-contact, high-resolution and whole-field measurement. The technique is a common measurement method for vibration mode visualization and surface displacement. Whole-field vibration mode shape (surface displacement distribution) at resonance frequency can be visualized by ESPI. And the maximum surface displacement distribution from ESPI can be used to find the resonance frequency for each vibration mode shape. And the elastic modules of a test material can be easily estimated from the measured resonance frequency and Euler-Bernoulli equation. The TA-ESPI vibration analysis technique can be used to find the elastic modulus of a material requiring simple preparation process and analysis.