An all-optical processor for 3D object recognition based on integral photography is presented. The optical processor consists of two subsystems: one is a projection system of a 3D object into an array of elemental images that have different perspectives of the 3D object and the other is an optical system to perform the 2D correlation between the corresponding sets of elemental images. A 3D object is illuminated by incoherent light and then is projected into an array of elemental images by use of a microlens array. Each elemental image corresponds to a different perspective of the 3D object. The set of elemental images contain information of the 3D object as shown in integral photography method. After an optical incoherent-to-coherent conversion by an optically addressed spatial light modulator, an optical system is used to perform the correlation between the input and the reference 3D objects. We present experimental and numerical results of the recognition of 3D objects. We also show that the system can recognize a slightly rotated 3D object.

Motion estimation is one of the fundamental problems in digital video processing. One of the most notable approaches of motion estimation is based on the estimation of a measure of the change of image brightness in the frame sequence commonly referred to as optical flow. The classical approaches for finding optical flow have many drawbacks. The numerical methods or least square methods for solving optical flow constrains are susceptible to errors in the cases of occlusion and of noise. Two moving objects having common border causes confliction in the velocities, and taking their averages yields a less satisfactory optical flow estimation. The wrong detection of moving boundary, as motion is usually not homogeneous and the inexact contour measurements of moving objects are the other problems of optical flow methods. Therefore, information such as color and edges along with optical flow has been used in the literature. Further, the classical methods need lot of calculations and computations for optical flow measurements. In this paper, we proposed a method, which is very fast and gives better moving information of the objects in the image sequences. The possible locations of moving objects are found first, and then we apply the Hough Transform only on the detected moving regions to find the optical flow vectors for those regions only. So we save lot of time for not finding optical flow for the still or background parts in the image sequences. The new Boolean based edge detection is applied on the two consecutive input images, and then the differential edge image of the resulting two edge maps is found. A mask for detecting the moving regions is made by dilating the differential edge image. After getting the moving regions in the image sequence with the help of the mask obtained already, we use the Hough Transform and voting accumulation methods for solving optical flow constraint equations. The voting based Hough transform avoids the errors associated with least squares techniques. Calculation of a large number of points along the constraint line is also avoided by using the transformed slope-intercept parameter domain. The simulation results show that the proposed method is very effective for extracting optical flow vectors and hence tracking moving objects in the images.

An x-ray vision can be a unique method to monitor in real time and analyze the motion of mechanical parts which are invisible from outside. Our problem is to identify the pose, i.e. the position and orientation of an object from x-ray projection images. It is assumed here that the x-ray imaging conditions that include the relative coordinates of the x-ray source and the image plane are predetermined and the object geometry is known. In this situation, an x-ray image of an object at a given pose can be estimated computationally by using a priori known x-ray projection image model. It is based on the assumption that a pose of an object can be determined uniquely to a given x-ray projection image. Thus, once we have the numerical model of x-ray imaging process, x-ray image of the known object at any pose could be estimated. Then, among these estimated images, the best matched image could be searched and found. When adequate features in the images are available instead of the image itself, the problem becomes easier and simpler. In this work, for simplicity, only polyhedral objects are considered whose image features consist of corner points and edge lines in their projection images. Based on the corner points and lines found in the images, the best-matched pose of a polyhedral object can be determined. To achieve this, we propose an adequate and efficient image processing algorithm to extract the features of objects in x-ray images. The performance of the algorithms is discussed in detail including the limitations of the method. To evaluate the performance of the proposed method a series of simulation studies is carried out for various imaging conditions.

Inspection and shape measurement of three-dimensional objects are widely needed in the fields of quality monitoring and reverse engineering. X-ray computed tomography could be a good solution since the method can acquire three dimensional volume information of a product from a series of acquired cross-sectional images. To reconstruct a cross-section in computed tomography, a number of data are required, projected from all but uniformly spaced view angles. In many applications of industrial field, however, it may not be possible to acquire such projection data obtained at all angles due to the size of objects or obstructed situation by other structures at some angles. In such a limited condition, analytical solution to reconstruct a cross-section is not available in general, and an iterative numerical method such as algebraic reconstruct technique (ART) and its modified algorithms, such as uniform and simultaneous ART methods, are used. In those iterative methods, the intensities of the image pixels in the reconstructed image are estimated and updated independently, thus the reconstructed image looks like a mosaic, of which the resolution is restricted to the number of image elements, pixels. In this paper, a new image reconstruction method is proposed based on a radial basis f function (RBF) neural network. In this method, a cross-section image is represented by RBF network, and is reconstructed through the learning process of the network. To achieve this, a learning method of the network is proposed here based on the projection of the image instead of the reference image itself. The algorithm is tested by a series of simulation studies on some of modeled images, and the performance of the proposed method is evaluated in terms of convergence and accuracy.

In a stereo-lithography, the most important procedure for improving an accuracy of modeling is to clearly identify the relationship between the method of laser irradiation and the solidification of photo-curing resin. Thus, a theoretical analysis was made in order to find any effect on the solidification, viz. Thickness and width of solidified resin influenced by laser power, laser beam diameters, laser scanning speeds, and properties of photo-curing resin, and these analytical results were compared with respective test results. The results are summarized below: (1) the cured thicknesss of solidified resin can be represented by a function of the energy density at the center of laser, the attenuation coefficient and the critical curing energy density of photo-curing resin. (2) The cured width of solidified resin can be represented by a function of laser beam diameters, the energy density at the center of laser and the critical curing energy density of photo-curing resin. (3) Photo-cured models, which have been manufactured by controlling energy density at the center of laser, would have high manufacturing accuracy, and therefore, can be applied as industrial design models.

Confocal scanning microscopy (CSM) has been used in biological application, materials science, semiconductor quality measurement and other non-destructive microscopic application. Small spot of light illuminates a sample, and a small detector that is ideally a point detector collects the reflected or transmitted light having the information of specimen. An image distribution can be reconstructed by a correlation analysis of spots with the high bandwidth. The mechanism for two-dimensional beam scanning and optical sectioning has an important role in CSM as the three-dimensional profiler. The parasitic motion of focus on the detector gives rise to the fatal distortion of an image profile named the extinction effect while using acousto-optical (AO) deflector. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. We propose the progressive methods for the high quality image as the following. At first, for having the corrected image, small spot and long scan range, this paper shows that the optimal design having the multi-objects can be used by choosing the unitary lens device in CSM. At second, in order to compensate for the intensity cancellation at the end profile that may be the cause of waviness for the optical image, this paper shows that it is efficient to schedule the frequency of scan. According to characteristics of the extinction curve and axial/lateral response having the error property, we can define the frequency and sensitivity of as their robustness. Finally, the axial response gives an important motive for the optical section, and the limit of object depth. The edge enhancement may be a fatal defeat to the reconstruction of image and sensitive to the conditions of specimen such as slope, irregular reflectivity, shape, etc. That means that the intensity profile for the open loop scanning method should be matched with its response to a perfect mirror as specimen, which can be minimized with the optical sectioning or the optical probe of the closed loop control.

A new display device based on a micro-Fizeau interferometer (IDD: Interferometric Display Device) is proposed and trially manufactured. The mirror is suspended by leaf-springs so that it may move vertically when driven by a dc voltage - electrostatic force. The optical path difference between the half mirror and the bottom substrate is adjusted by the voltage, resulting in the optical interference. Contrast in the IDD can be changed by the voltage, and color can be displayed in the case of white light source. A 300micrometer-square half mirror made of SiO2 and Si substrate electrode/mirror is used for the construction of the IDD. A 4 by 4 array of the IDD is fabricated by using a bonding technique. An interferometric pattern in observed at a driving voltage of 200V dc. The frequency response of the device is confirmed more than 100Hz. The display quality is not sufficient at present because of the deformation of the half-mirror, however, it has a potential for lower driving energy and higher intensity of the pixels.

Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. A number of visual or optical technologies have been successfully applied to measure three dimensional surfaces. Especially, the shape measurement using an interferometric principle becomes a successful methodology. However, those conventional interferometric methods to measure surface profile have an inherent shortcoming, namely 2π ambiguity problem. The problem inevitably happens when the object to be measured has discontinuous shape due to the repetition of interferometric signal with phase period of 2π . Therefore, in this paper, we choose as a shape measuring method Wavelength Shifting Interferometer (WSI) in which the absolute distance from the reference surface can be directly obtained from the amount of interferometric phase change. With the above advantage the coplanarity of ball grid array (BGA) can be easily evaluated and inspected, which is the major factor in the BGA surface mounting technology. The WSI is basically composed of a Twyman Green Interferometry and a tunable laser source. The proposed WSI so far by other researchers suffer from low measurement resolution because of the methodological roughness in obtaining interferometric phase change. Therefore, we propose a new algorithm, which can obtain a small amount of even fractional phase change by sinusoidal function fitting. To evaluate the effectiveness of the proposed sinusoidal function fitting algorithm, a series of measurements is conducted for discontinuously shaped specimens which have various heights. The proposed algorithm shows much more enhanced measurement resolution than other existing conventional algorithms such as zero crossing algorithm and Fourier transform algorithm. To measure the three dimensional shape of ball grid array with WSI, a series of simulations was performed for a hemispherical ball model in which the diffuse surface conditions are considered. The simulation results show that the three dimensional shape of a ball can be measured using WSI for purpose of BGA product inspections.

Current manufacturing processes require rapid, reliable methods and compact, user-friendly, elegant devices capable to work even in unpromising environment. Innovative user- friendly methods and techniques as well as small holographic and speckle interferometers are presented in this paper. The devices are very compact, easy to operate, incorporate semiconductor laser sources and do not require personnel skilled in optics. Miniature semiconductor laser sources were successfully used in holography and laser speckle metrology for the tasks of 3-dimensional data acquisition, storage and display. Semiconductor lasers enable compact recording and display devices which are easy in operation and well fitted to practical industrial environments. Novel inspection methods and compact devices incorporating miniature semiconductor laser sources can be applied for automated inspections and optical precision measurements in optomechatronic systems. They fit well for real time monitoring of local deformations. Presented devices and techniques meet modern industrial requirements and permit to work in unpromising environment, perform in situ checks of products and components. Vast experimental data are given and the possibilities of innovative devices and techniques are properly illustrated in multiple practical examples. Photographs from holograms and holographic interferograms recorded with semiconductor lasers and successive sets of snapshots during real time monitoring of thermal fields are presented.

The accurate measurement of the position and orientation of a robot manipulator's end-effector is the most critical issue for calibration of the robotic devices. To accurately define a position and orientation of a robot manipulator's end-effector, measurement of six parameters is required - three for position and three for orientation. Different approaches have been studied over the last few years to measure the orientation of the end-effector dynamically and precisely. However, there are still some difficulties in determining the orientation of the end-effector in real time. In this paper, an orientation measurement methodology based on Position Sensitive Diode (PSD) measurement in laser interferometry-based sensing and measurement technique will be described. The principle and algorithms of this approach will be presented. The experimental set-up will also be described. The efficiencies and limitations of such approach will be examined.

Lead Frame is a core part of semiconductor IC and is used as a conductor to transmit electrical signal. In this study, an inspection system was developed that has utilized linear cameras and a method has been proposed for an automated inspection of LF. Mathematical morphology has been employed for the inspection. A modified thinning algorithm was proposed and has been used to make a master pattern of LF. The proposed method follows three steps to evaluate the quality of product. It is the first step to place the master on an object image precisely. Those have abnormal gray values in the object, are extracted as defective candidates. The last work is to evaluate the candidates according to a heuristic rule of decision. The proposed method has shown a good efficiency for the inspection of LF> It has been possible to find defect in a fast way and given minimal misjudgement. The proposed method is also efficient in inspecting etched products e.g. PCB and tape μBGA.

To improve task performance in partially structured environments, enhancements to teleoperation have been proposed by introducing autonomous behaviors. Such autonomy is implemented based on a reactive robotic architecture, where reactive motor agents that directly couple sensory inputs and motor actions become the building blocks. To this end, a perceptual basis for the motor agents is presented in this paper. The perceptual basis consists of perceptual agents that extract environmental information from a structured light vision system and provide action-oriented perception for the corresponding motor agents. Rather than performing general scene reconstruction, a perceptual agent directly provides the motion reference for the motor behavior. Various sensory mechanisms - sensor fission, fusion, and fashion - become basic building blocks of the perception process. Since perception is a process deeply intertwined with the motor actions, active perception may also incorporate motor behaviors as an integral perceptual process.

Hand/eye calibration is useful in many industrial applications, for instance, grasping objects or reconstructing 3D scenes. The calibration of robot systems with a visual sensor is essentially the calibration of a robot, a sensor, and hand-to-eye relation. This paper describes a new technique for computing 3D position and orientation of a 3D visual sensor system relative to the end effector of a robot manipulator in an eye-on-hand robot configuration. When the position of feature points on a calibration target in sensor coordinates viewed at each robot movement, and the position of these points in world coordinates and the relative robot movement between two robot motions are known, a homogeneous equation of the form AX equals XB can be derived. To obtain the unique solution of X, it is necessary to make two relative robot arm movements and to form a system of two equations of the form: A₁X equals XB₁ and A₂X equals XB₂. In this paper, a closed-form solution of this calibration system is derived, and the constraints for existence of a unique solution are described in detail. Test results obtained through a series of simulation show that this technique is a simple, efficient, and accurate method for hand/eye calibration.

The optical micromachines controlling the light in spatial and wavelength domains are based on the micro- optomechatronics which handles small objects in micrometers and covers the fields from monolithic fabrication and control techniques. Their advantageous features include quick response, high mechanical stability, and low driving power because of the small inertia effects. A wide variety of functions such as wavelength tuning and optical path switching has been realized. This paper describes typical applications corresponding to these functions and their possible implementations: optical manipulation for small optical components based on momentum transfer of photons, micro lenses fabricated monolithically on a substrate for optical integration circuits, tunable filters with moving mirrors driven by the electrostatic force fro pulse shaping, and optical switches based on thermo capillary for cross connect or add/drop multiplexing operations in network systems. These applications are useful for next-generation photonic reconfigurable networks.

Photonic devices with ultra-wide and precise controllability for lightwaves are essential for constructing flexible optical networks to serve versatile multimedia applications. However, conventional monolithically fabricated photonic devices suffer from their controllability being limited by the physical characteristics. Micro-optomechatronics based on precise positional control of optical elements is a promising method of meeting the above requirements. This paper presents typical examples, which include repetition- rate tunable optical pulse sources with a micro mechanically controllable cavity length and synchro-scanned tunable disk- shaped optical fiber modules. The operations of these modules were demonstrated to confirm the validity of micro- optomechatronics as the ultimate lightwave control scheme, which will be useful for future optical telecommunications systems.

New single-mode fiber collimator arrays (FCAs) were designed, assembled, and tested at a wavelength of 1550 nm. For FCAs using an 8-channel GRIN planar microlens array with a pitch of 250 μm and a focal length of 0.7 mm, the insertion loss was 0.5 dB with uniformity of 0.12 dB, at a collimator separation of 10 mm. The crosstalk from the other channels was less than -45 dB and the return loss of each channel was > 60 dB. For FCAs using a 6-channel lens array by fixing GRIN rod lenses into a V-groove array, the insertion loss was less than 0.5 dB at a collimator separation of 100 mm. By analyzing formulas for calculating Gaussian beam propagation for the design, some simple and useful formulas were introduced for calculating the size and position of the beam waist from those of its image, and for calculating the maximum collimator separation with efficient coupling.

We propose a scheme for reduction of cross-talk arising form stop-band rejection limitation of optical band-pas filters in a wavelength-division multiplexing receiver. Experiment confirms high selectivity of the receiver and reveals feasibility of optical packet ultra dense WDM systems spaced by several GHz. The receiver consists of optical switches at input and output ports of a fiber loop, which contains fiber delay line, tunable optical band-pass filters, an erbium-doped fiber amplifier, and an optical switch. Target packet is selected from input optical packet WDM signals by time and wavelength windows realized by the optical switches at the input and output ports of the fiber loop, and the tunable filters in the loss compensated fiber loop, respectively. The selectivity is measured by using pulsed lightwave sweep frequency, which contains 7 frequencies in 500MHz step. The results show 11dB suppression for signals 2 GH apart from the target channel after 10 circulation, and 12dB suppression for signals 1.5 GHz apart from the target channel after 18 circulation. Details of the receiver configuration, pulsed lightwave sweep frequency generator and experimental results are discussed.

A novel optical crossconnect architecture, capable for tens of terabit throughput and allowing the integration of wavelength and space switching, is presented for both WP and VWP networks. The architecture offers significant advantages in terms of crosstalk performance and node complexity. In the architecture, there are no crossovers and crosspoints. Therefore, the signal-to-crosstalk ratio per wavelength channel can be very high since each channel is processed independently from the others. This will also allow to introduce other all-optical techniques like adding/dropping of OTDM channels as well as optical regeneration. The proposed architecture is wavelength and link modular and particularly suitable for crossconnects with a very large number of wavelength channels. Performance aspects of a single as well as of a cascade of crossconnects have been simulated using a simulation tool.

The irresistible growth in capacity demand for optical transmission systems calls for an increase in both channel granularity and bit rate, while maintaining signal quality. The document reviews recent developments in the field of all-optical regeneration and show its potential to meet the challenge with cost-effective implementation. We also report a 160Gbit/s all-optical regenerator based on the simultaneous optical regeneration of four 40Gbit/s WDM channels in a single polarization-insensitive modulator chip by using an all-optical cad simulation tool. Regenerated transmission with 0.2(bit/s)/Hz spectral efficiency is achieved over 10,000km distance.

An optical actuator features characteristics such as energy supplied remotely in wireless and no generation of magnetic noise. We proposed a new type of an actuator that is driven by the light. It is composed of three optical fibers as a leg jointed to a base. The fiber cut at an angle at the end is occurred a photothermal effect respond to flashed incident beam with a constant cycle from other side of the fiber. This effect makes the end of fiber a stretching vibration. A size of the optical actuator is 3 x10 mm and it moved 25 micro-mm per second at 12mW (4Hz) of input power. We discuss these experimental procedures and the results of movement.

A discrete-time Preisach model that captures hysteresis in a piezoceramic actuator is developed. The model is implemented using a numerical technique that is based on first order reversal functions and is presented in a recursive form that is amenable for real-time implementation. The first order reversal functions are experimentally obtained using a piezoceramic actuator in a stacked form. The development model shows good agreement with actual measured data. A hysteresis compensation scheme based on the developed discrete-time Preisach model is also developed and used in order to obtain a linear voltage-to-displacement relationship.

Optically driven small machines have such features as easily miniaturized in fabrication and as controlled by optical energy supplied in wireless. We report an optically controlled machine which moves like a catepillar on the basis of photo-thermal effect. This miniaturized machine fundamentally consists of two parts: a body made of shape memory alloys and springs and feet made of magnets and temperature-sensitive ferrites. Th effect can stick to the carbon steel floor due to magnetic force balance caused by projected beam, and the body repeats stretching and shrinking using deformation of shape memory alloys caused by switching on and off of projected beam. A prototype is fabricated in trial with a size of 35 mm by 12 mm. As an experimental result, it proved that they could move at the speed of 8.7 mm per cycle on a ceiling as well as on a horizontal floor and it could climb a slope as steep as 50 degree. To improve the ability of this prototype, we newly developed a smaller machine with the total length of 20 mm by 15 mm and the weight of 1.1 g. Because of lighter weight of this machine, it could climb any slope including a vertical wall.

Considering system stability, the tracking servo system of electro-optical theodolite is often designed as type I servo system. In principle steady state velocity error and acceleration error exist in it. Especially when tracking fast moving targets, the tracking error will become bigger. To minimize the tracking error a higher order servo system can be used. However, it is very difficult to keep such servo system stable. In this paper a kind of dynamic type II servo system according to Fuzzy logic theory was designed to solve the above contradiction successively.

A stable adaptive controller is reported here for a class of system with state dependent parasitic effects such as friction. The methodology is constructive, and ensures stable and convergent performance. The control design is applicable to a class of dynamic systems working at low speed with the cited parasitic effects. The design is verified by simulation and a hardware example case.

Non-contact measuring methodologies of 3D profile using CCD camera are very attractive because of their high measuring speed and high sensitivity. When projecting a grid pattern over the object, 3D information of the object can be extracted from the projected pattern image. Projection moire using a such a projected pattern image is used to extract 3D information with another grid pattern in front of CCD camera. As an alterative method to projection moire, phase measuring profilometry (PMP) without such an additional grid pattern is used to obtain similar but improved results under practical measurement environment. This paper describes a new PMP technique with improved practicality. In this technique, three or more snapshots over object undergoing dynamic motion with respect to camera are all that is required to capture the 3D surface contour of the object. This technique is principally similar to the existing PMP techniques using multiple phase shifting images and it provides a similar resolution. However, this enables the contouring speed to be increased up to the frame rate of the camera because it is not necessary for object or camera to be in static during snapshot. Furthermore, it also makes contouring at a reasonable resolution and accuracy possible because very highly intensive light sources like LED or halogen can be used for high contrast. The principle of the technique is described and some preliminary experimental results are presented. Experimental results demonstrated the feasbilitity of the technique for high-speed surface profile measurement.

As PCB components become more complex and smaller, the conventional inspection method using traditional ICT and function test show their limitations in application. On the contrary, the automatic optical inspection (AOI) gradually becomes the alternative in the PCB assembly line. In particular, the PCB inspection machines need more reliable and flexible object recognition algorithms for high inspection accuracy. The conventional AOI machines use the algorithmic approaches such as template matching. Fourier analysis, edge analysis, geometric feature recognition or optical character recognition, which mostly require much of teaching time and expertise of human operators. To solve this problem, in this paper, a statistical learning based part recognition method is proposed. The performance of the proposed approach is evaluated on numerous samples of real electronic part images. Experimental results demonstrate satisfactory performance and practical usefulness in PCB inspection processes.

With the increasing necessities for reliable PCB product, there has been a considerable demand for high speed, high precision vision system to place the electric parts on PCB automatically. To identify the electric chips with high accuracy and reliability with obtained images, a classification algorithm is needed to identify the type of parts and their defects. In this paper, we design a learning vector quantization (LVQ) neural network to achieve this. From the images obtained under the versatile lighting system, characteristic features for classification are extracted, from which type of chip is identified through the neural network based classification algorithm.

We developed a high-resolution absolute optical encode that achieves a resolution of 4,194,304 Division/Rev at a diameter of 34mm, based on the new angle detection principles, by which the two sets of interpolation data of two differing cycles and M-Code data are mixed. This absolute encoder also achieves an accuracy of 20 seconds to minimize the sinusoid wave distortion of the signal from the photo detector.

The frequency response of force-measuring microlaser sensors (Nd:YAG) is tested in a special opto-mechatronic test setup. In this setup a piezo translator/frame configuration generates sinusoidal forces in the range from DC up to 100 kHz and higher. The force amplitude covers a range of approximately eight decades (1 N - 10 nN). Amplitude and phase response of the test setup including the laser sensor under test are measured. Because of the frequency-analogue output signal of the laser sensor, dynamic frequency measurements based on frequency/period counting, Bessel spectrum analyzing and FM-demodulation have to be performed. To conclude on the dynamic response of the microlaser itself the mechanical part of the test setup and the laser sensor is modeled mathematically. The theoretical response of the test setup is in good agreement with its measured frequency response, which means that modeling of the force-to-frequency conversion by the laser sensor is realistic. Based on static and dynamic measurement data, we conclude an excellent proportional response of the laser sensor for modulation frequencies up to 100 kHz. In this frequency range, the characteristics of the force-to-frequency conversion are strictly linear over approximately nine decades.

A new measurement method to measure vibrational motions of objects is presented. The original principle is similar to the previous work that utilized a 3-facet mirror to obtain three dimensional positions and orientations of rigid bodies. While the previous work was presented for only stationary objects, in this paper, we newly investigate the feasibility of this method for dynamic applications. The 3-facet mirror that looks like a triangular pyramid having an equilateral cross-sectional shape. The mirror has three lateral reflective surfaces inclined 45 degrees to its bottom surface, and is mounted on the object whose motion is to be measured. As optical components, a He-Ne laser source and three position-sensitive detectors (PSD) are used. The laser beam is emitted from the He-Ne laser source located at the upright position and vertically incident to the top of the 3-facet mirror. The laser beam is reflected from the 3-facet mirror and splits into three sub-beams, each of which is reflected from the three facets and finally arrives at three PSDs, respectively. Since each PSD is a 2-dimensional sensor, we can acquire the information on the three dimensional position and orientation of the 3-facet mirror. From this principle, we can get the motion of any object simply by mounting the 3-facet mirror on the object. In this paper, the measurement principle and a series of experiments are presented. The experiments include measurements of vibrational motions of a piezoelectric actuator that moves the 3-facet mirror in a single axis. The experimental results are compared with those of a laser doppler vibrometer. Through the experiments, the proposed sensor is proven to be an effective means for measuring dynamic motions of objects.

The fabrication of an electric field detector using electro- optic LiNbO₃ (LN) single crystal has been studied for the application to check the electric field of a conductively patterned panel. When this electric field detector moves on the surface of the panel, air gap which is close enough for the given field intensity and resolution has to be maintained constantly not to damage the patterns on the surface For the effective detection of electric field change in this air gap state, LN single crystal was selected because of the relatively high electro-optic coefficient, transmittance and low dielectric constant. X-cut LN and Z- cut LN structures were selected to estimate the applicability of LN single crystal by the simulation on the optical intensity variation and electric field distribution of the various structures. As the air gap was increased from 0 to 40 (μm) in the X-cut LN structure, half-wave voltage (V_π) was increased from 400 to 700 (V) and optical intensity variation with unit voltage (Q) was decreased from 1.3 to 0.17. At the air gap of 10 μm in the Z-cut LN structure, (V_π) was about 100-150 (V) and Q was 6.7 (%/V) much larger than that of the X-cut LN structure. Form these characteristics, Z-cut LN structure proved to be applicable for the electric field detector because the optical intensity variation (.08μW) was sufficient in the ac driving voltage region (±20 V) of the real system.

A moire method using phase shifting technique is proposed for a flatness measurement, with highly accurate and fast measurement time. Two new methods are suggested for the elimination of the reflected light from the back plane of the glass substrate and for the reduction of contour line errors caused by waviness or warp of the sample surface. The former is UV moire technique and the latter is angle error reduction technique. In the UV moire technique a light of the 313nm wavelength is used for generating a moire. The light is able to eliminate the reflection from the back plane of the Liquid Crystal Display (LCD) glass substrate because it is absorbed inside the glass. The angle error reduction technique is to extrapolate data, which are measured in different distance between grating and sample, because the angle error is proportional to the distance between grating and sample. Using these two techniques, the proposed system realizes less than 0.6 microns in accuracy, while the conventional system is more than 10 microns in accuracy.

A new voltage sensing method has been tried using a n electro-luminescence effect. Optical images of the electric potential of conductive planar patterns could be obtained by this method. The brightness of the sensor surface is proportional to the voltage that is applied to the pattern electrode and the image is captured. By processing the image, defective part of the pattern electrode can be identified. This method is contact-free so that it can be applied to what is covered by an insulator layer. Also, we propose a driving method of the sensor that enables measuring DC voltages. This method may be applied to what is covered by an insulator layer. Also, we propose a driving method of the sensor that enables measuring DC voltages. This method may be applied to inspect the fine conductive patterns in non-contacting way during the fabrication process of display devices such as thin film transistor liquid crystal display panels.

In this paper, we present a 3-step auto-alignment algorithm for the incident angle of an ellipsometer without auxiliary equipment. The 3-step algorithm uses only a 3-axis precision stage (two rotation and one translation) for ellipsometric incident angle alignment, and consists of two incident angles and its following corrective process. The corrective process is to position the spot on the center of the detector's aperture plane, and consists of accessing and centering on the detector's aperture. In the first step, the polarizer and analyzer arm are set at a proper incident angle and the spot is centered on the detector's aperture by the corrective process. In the second step, the polarizer and analyzer arm are set at a measured incident angle and the spot is centered on the detector's aperture by the corrective process. In the third step, height error and angle errors of the specimen are calculated with the stage's angle from the first and second steps. Finally, locating the specimen stage at an errorless position completes incident angle alignment. We modeled 3-D optical paths using a homogeneous transformation matrix (HTM), and simulated the developed alignment algorithm. The results showed that the developed alignment algorithm works well. Experiment results also revealed good agreement on the simulation. The developed alignment algorithm may be applied to other alignment problems, such as tilt alignment of lithography.

This paper presents a new non-contact method for measuring 3-D features of biological materials. The method can provide 3-D images of samples under liquid such as water with a microscopic resolution. One of the advantages of measuring under liquid includes protecting air sensitive surfaces of biological materials. The method is based on optical microscopy with machine vision and precision actuation. The geometric information of 3-D samples can be obtained by analyzing the focus errors of the image pixels. Experimental results have been presented and discussed to demonstrate the technique.

An important task in reverse engineering and computer-aided- design applications is to create a mathematical model of surface geometry based on coordinate measurements. A two- step techniques that fits parametric surfaces to partial or whole human body measurements for free-form surface reconstruction is described in this paper. The first step of the proposed technique employs a self-organizing feature map to adaptively parameterize non-uniformly spaced coordinate points. The second step uses a Bernstein Basis Function (BBF) network to fit a deformable Bezier surface to the parameterized data. Once the adaption phase is compete, the weights of the BBF network can be utilized by a variety of commercially available geometric modeling and CAD/CAM packages for shape reconstruction. An experimental study is presented to demonstrate the effectiveness of the BBF network for generating smooth Bezier surfaces of complex anatomical shapes.

An optical transducer based on the light modulated transmission properties of bacteriorhodopsin (bR) film is described in this paper. The bR protein molecules undergo a complex photocycle when absorbing light energy that is characterized by several measurable states. The most relevant states in the photocycle for this application are the initial B state (λ_max= 570 nm) and the longest lived M intermediate state (λ_max= 410 nm). If a yellow light source with a wavelength of approximately 570 nm and a second deep blue source at 410 nm illuminate the same region of the thin bR film, the two beams will mutually suppress the optical transmission properties of the thin film and reduce the intensity of the light output. The suppression-modulated transmission mechanism of the bR polymeric film is, therefore, controlled by the intensity and wavelength of the two light sources. Based on this simple mechanism, a number of different protein-based optical devices have been proposed in the literature for optical signal and information processing. The focus of this research is to exploit the light transmission properties of the bR film to develop efficient optical transducers that can be easily interfaced with micro-electro-mechanical systems for mechatronic applications. The proposed transducer design is activated by an external light source and free from electrical noise. Illustrations of how thin bR film can be used for the modulation of light intensity, optical switches, and logic gates are presented.

A phase reversal speckle interferometric (PRSI) system is developed for precise measurement of in-plane displacement component of a deformation vector with twofold measuring sensitivity. In the system, the phase reversal is accomplished by varying the pressure within an air field quartz cell inserted in one of the observation arms of a dual beam symmetric illumination-observation arrangement. The work reported here is classified into two parts: the first part illustrates a novel real-time phase reversal speckle photography technique for exact π-phase shift calibration using a two wave coupling arrangement in a BaTiO₃ photorefractive crystal as a recording medium. The second part consists of simultaneously providing object deformation and an exact phase shift of π between the exposures using PRSI system to achieve twofold measuring sensitivity.

In this paper, a vision-based inspection system that measures the dimensions of a ball stud is designed and implemented. The system acquires silhouetted images by backlighting and extracts the outlines of the nearly dichotomized images in subpixel accuracy. The sets of boundary data are modeled with reasonable geometric primitives and the parameters of the models are estimated in a manner that minimizes error. Jig-fixtures and servo systems for the inspection are also contrived. The system rotates an inspected object to recognize the objects in space not on a plane. The system moves the object vertically so that it may take several pictures of different parts of the object, resulting in improvement of measuring resolution. The performance of the system is evaluated by measurement of the dimensions of a standard ball, a standard cylinder, and a ball stud.