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Issue 3 ， 2004
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Design of a subminiature anti-particles load-supporting stage for near-field optical storage
Abstract：In order to meet the requirements of the near-field optical storage system for higher density, higher communication speed and integration, a subminiature anti-particles load-supporting stage was designed for low wear and high near-field coupling efficiency. A model of air bearing surface was investigated and solved using the finite volume method for analysis of the flying characteristics. The abundant negative pressure sufficiently enhances the stiffness and stability of the stage. The wedge-shaped rails and the novel distribution of negative force efficiently reduce the particles. The rail etched on the SIL achieved ultra sub-micron displacement from the disk surface. The theoretical analysis and computation show that a near-field gap of less than 50 nm can be successfully obtained. The carrying capacity exceeds 88 mN. Few particles are retained under the SIL. The flying head is robust for the near-field optical system.Keywords：subminiature load-supporting stage;air bearing surface;wedge-shaped rail;negative pressure;near-field optical storage- 40
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Published：2020-08-12 -
Design of contact lenses projection measuring instrument
Abstract：With the demand for contact lenses increasing, measurement instrument and technology are needed for measuring the important parameters of contact lenses. A new method is proposed to use optical projection and self-scanning photodiode array to measure the curvature, optical center thickness and diameter of contact lenses. A new instrument based on the method has been successfully designed for measuring contact lenses. Its precision is superior to ?0.1 mm in lenses curvature, ?0.01 mm in optical center thickness, and ?0.1 mm in diameter. The measuring principal, special construction, signal sampling process of this new instrument and the design of the single-chip microcomputer hardware and software system are discussed in detail.Keywords：measuring projector;contact lenses;photodiode;curvature;optical center thickness- 58
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Published：2020-08-12 -
Adaptive correction of multi-range measuring errors of laser resistor trimming machine
Abstract：An adaptive correction method based on the measuring theory of Wheatstone bridge is proposed to reduce the effect of the multi-range measuring errors of a laser resistor trimming machine on the resistance adjusting accuracy. The corrected values in series to be used for correction of multi-range measuring errors of laser resistor trimming machine are adaptively obtained by measuring and calibrating the measuring errors of high precision standard resistors, and they can be used to correct all the resistance measuring errors of resistors to be adjusted to further reduce the system measuring errors. It is proved in practice that if a measuring system has good stability and low fluctuation, the precision of measuring system could be ±0.5‰ in low resistance(R<100 Ω)zone; ±0.2‰ in middle resistance zone; ±2‰ in high resistance(R≥1 MΩ)zone.Keywords：laser resistor trimming machine;Wheatstone bridge;Measuring system;measuring error;resistor calibration- 51
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Published：2020-08-12 -
Colorimetric density method for color space conversion of color printer
Abstract：A new method is proposed for color space conversion of color printers. Based on the concept of colorimetric density and artificial neural network, the one-dimension relationship between colorimetric characteristics of primary colors and printing data and the three-dimension colorimetric relationship between complex colors and primary colors were established together with the relationship between the two color spaces, output colorimetric space and input data space. Experiments were made with 729 samples and the experimental results showed that the conversion accuracy of this method is higher than those of some other methods, which build direct relationship between output and input. For one printer, the mean and maximal CIELAB c.d.(color difference)of 729 samples are 3.18 and 16.0, respectively, and these of 260 test samples are 4.00 and 16.8.Keywords：colour printer;color space conversion;colorimetric density;polynomial fit;artificial neural network;color difference- 62
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Published：2020-08-12 -
Application of Zemax software in alignment of three-mirror off-axis aspherical optical system
Abstract：With the aid of Zemax software, a three-mirror, unobscured, high-resolution optical system with large aperture, long focal length was successfully aligned by first collecting interferograms from several fields of all image plane, and obtaining the wavefront error, namely, obtained wavefront Zernike polynomials; then using the self-made program package to calculate the optical system misalignment. Finally, comparing Zernike polynomial coefficients of ideal optical system with Zernike polynomial coefficients of aligned optical system, and drawing a conclusion about the alignment correction values. It is simple and valid. After alignment, the optical system produced a measured wavefront error across the all image plane of 0.108 waves RMS at λ=632.8 nm.Keywords：computer-aided alignment;Zemax software;off-axis three-mirror optical system- 81
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Published：2020-08-12 -
Observation and measurement system for microstructure based on three-direction fiber illumination
Abstract：This paper introduces a new three direction illumination system with light intensity, angle of incidence and distance of incidence precisely real-time regulated is proposed for observation of 3D microstructure of MEMS. Three-dimensional images and the surface of the microstructure can be achieved by using this system. In the process of designing the surface matrix CCD micro-measurement system, calibration errors have a direct effect on the measurement accuracy of the system. A new method, which is simpler, faster, more convenient and more applicable than the traditional method, is proposed to calibrate and reduce calibration errors. The calibration accuracy of the system is up to(±0.0015)μm and its measurement accuracy is up to ±1 μm. This system is suitable for calibration at the level of micron.Keywords：MEMS;illumination;charge-coupled device;micro measurement;calibration error- 37
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Published：2020-08-12 -
Wavelet transform and its application in extraction of micro-resonator motion track features
Abstract：According to the characteristics of micro-resonator motion images, wavelet transform is used to extract the micro-resonator motion track features. Based on the blur image synthetic technique, wavelet transform was applied to enhance and abate noise of blur micro-resonator motion images, while the traditional image processing method is used to extract the motion track features, and finally the natural parameter of micro-resonator was acquired as important reference for MEMS design. In comparison with traditional image processing method, wavelet transform method has better measurement resolution, and its measurement repetition error is 100 nm.- 50
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Published：2020-08-12 -
Dynamic simulation and testing of a novel piezoelectric nanomotor
Abstract：A nanometer precision stepper piezoelectric motor has been designed and fabricated based on converse piezoelectric effect. From the simple model established from the motor's configuration, dynamic characteristic equations are deduced with pulses applied on the piezoelectric stack. The movement of the motor was simulated with some coefficients applied. The results of the simulation show that the motor is a linear stepper motor. A grating testing system was designed to test the piezoelectric motor. The experimental results prove that the simulations are true. This piezoelectric nanomotor can achieve serial step movement at higher speed with higher resolution in longer range, and it is easy to control by computer. The displacement resolution of the motor could be 10 nm at 0.6 mm/s in the range is 5 cm.Keywords：nanomotor;piezoelectric crystal;actuator;grating testing system- 71
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Published：2020-08-12 -
H-MRTD simulation of dual-frequency miniature patch antenna
Abstract：A novel MEMS dual-band patch antenna is designed using slot-loaded and short-circuited size-reduction techniques. By controlling the short-plane width, f10 and f30, two resonant frequencies, can be significantly reduced and the frequency radio(f30/f10)is tunable in the range 1.7～2.3. The Haar-Wavelet-Based multiresolution time domain(H-MRTD)is used for modeling and analyzing the antenna for the first time. In addition, the mathematical formulae are extended to an inhomogenous media. Numerical simulation results are compared to those achieved using the conventional 3-D finite-difference time-domain(FDTD)method and measured. It has been demonstrated that, with this technique, space discretization with only a few cells per wavelength gives accurate results, leading to a reduction of both memory requirements and computation time.Keywords：dual-frequency antenna;H-MRTD method;FDTD method;MEMS;UPML absorbing boundary conditions- 63
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Published：2020-08-12 -
Design of RF MEMS resonator components based on cavity structure
Abstract：The structure and performance of a complex cavity Micro-Electro-Mechanical-System resonator are analyzed with its electromagnetism equations established. Its fabrication was realized by built micromachining, and the structure is simulated on computer at the end. A micro machined-cavity resonator was designed with a TM010 resonance quality factor of 3 529.707890 at 24.313299 GHz. When the micro-strip coupling conditions are considered, the best guess for the highest eigen frequency would be 24.75 GHz, and the average error of theoretical results and simulated results is less than 1%. The simulation results are in very good agreement with the theoretical value and this testifies the feasibility of the design. The structure parameters of the component are further varied, to obtain multivarious frequency components. The resonance frequency of a component is reduced by filling high permittivity medium, and this makes it possible to keep the design of a component compact at low frequency even.Keywords：MEMS resonator;cavity structure;micromachining technology;MEMS design- 57
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Published：2020-08-12 -
New wavelet-based algorithm for denoising of multifractal images
Abstract：A novel multifractal image denoising approach based on singularity structure analysis is proposed to overcome the difficulty in estimating the multifractal spectrum of discrete data for multifractal analysis. By defining the partition function for moments of the wavelet coefficients, a new estimator for multifractal spectrum is given. There is no assumption for the type of noise or global smoothness of original data, and the image is characterized by its multifractal spectrum. The Hausdorff exponent of the image is processed by defining a new transformation operation, so that most of the points in the denoised image lie in the smooth regions while the relative strength of the singularities is preserved. Experimental results show that the method proposed leads to a smooth image and preserves the texture information of original images very well.Keywords：image processing;wavelet;multifractal analysis;Hausdorff exponent- 81
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Published：2020-08-12 -
Fast image matching algorithm based on template sampling
Abstract：A fast image matching algorithm was proposed to increase the running efficiency of the algorithm, and meet the real-time requirement for some applications. A gray edge image of the template was extracted using Sobel marginal operator. Matching points were sampled from the gray edge image and utilized to reduce the time complexity of the matching process. At the same time, the global searching mechanism of the genetic algorithm was exploited to expedite the convergence of the algorithm to the sub-optimal solution to the problem. Based on it, a precisely locating phase was introduced to fix the location and rotating degree of the optimal target sub-image in the scene image. Practical application of the algorithm to the image matching system of a fully automatic gold wire bonder demonstrated that the algorithm could meet the real-time requirement and the locating precision requirement of the system, and they worked as expected.Keywords：image matching;genetic algorithm;fully automatic gold wire bonder- 40
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Published：2020-08-12 -
Development and application of Iris recognition technology
Abstract：Iris identification technology is a biological characteristic identification technology with the lowest error reception rate and the lowest error refusal rate. It differentiates accuracy from error of identification by collecting iris image, abstracting features and matching features. Because of its commonness, uniqueness, reliability and also anti-interference, this technology has high academic value and very wide future applications. Through the complete analysis of current research situation, identification frame-work, and system component, acquisition and pretreatment of iris image, extraction of features, matching of features and evaluation of performance are discussed, and the problems of this technology, such as the difficulty of acquiring high quality images, and stability and feasibility to be testified are reviewed as well. The direction of further research and development and future application of this technology cover the fusion of iris identification information with other biology identification information and non-biology identification information; set-up of iris identification network system; highly efficient identification calculation and identification chip with commonness and strong compatibility.Keywords：image processing;private authentication;iris recognition- 63
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Published：2020-08-12 -
Fast orthogonal edge projection algorithm for inspection of film defects
Abstract：A fast orthogonal edge projection algorithm is proposed for real-time inspection of film defects on production line. By analyzing the characteristics of infrared images of film, using image-processing techniques including neighborhood averaging, edge detection and projection method, etc., and compiling the VC++ program film defects are quickly identified. In this process, the key is the projection method that transforms two-dimension images into two one-dimension vectors. Furthermore, new functions, such as evaluation of defect area and severity can be added to the algorithm in accordance with the actual requirements. On-line experiments in Lucky Film Corp. proved that the algorithm can detect all kinds of film defects and process a 659+494 image within 20 ms.Keywords：image segmentation;projection;edge detection;film defect- 86
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Published：2020-08-12 -
MR fluids for finishing use
Abstract：The principle and characteristics of magnetorheological finishing(MRF)are introduced, and a standard is suggested for evaluation of MR fluid finishing of optical glass. The elements of MR fluid were chosen according to the standard and MR fluid was prepared for optical finishing. The yield stress of this MR fluid is 70 kPa at a shear rate of 110 rad/s and in a magnetic field of 600 mT. An experimental finishing was conducted with K9 optical glass using the developed MR fluid, and experimental results show that the maximum removal rate of optical glass is 0.4 μm/min.Keywords：magnetorheological;fluid;shear yield stress;removal rate- 63
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Published：2020-08-12 -
High performance irregular multi-layer coating machine
Abstract：Leybold APS 1104 DWDM is a coating machine specially designed for coating DWDM thin film filter, and it has the difficulty in coating non-QWOT films consisting of multi-decades layers. Through in depth analysis of its characteristics, some design methods are suggested for coating QWOT film. By using these methods, coating high performance thin film filters is finally achieved.Keywords：multi-layer coating;Leybold;irregular series of film;coating machine- 46
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Published：2020-08-12 -
Numerical simulation and characterization of materials' porosity, pore size, and surface roughness
Abstract：The surface roughness of mirrors determine the quality of imaging in an optical system, and it depends on the optical processes and the characteristics of material itself, for example, the grain size, flaws, porosity and pore size of materials have great effect on the surface roughness. Therefore, a model was built by geometry method for the relationship between porosity ρ and pore size d, the function relationships among number of pores NV or NS are described. Another model used to simulate the effect of porosity and pore size on surface roughness RA was constructed by mathematical method. The dependence of RA on ρ and d is given.Keywords：optical material;porosity;pore size;surface roughness;numerical simulation- 58
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Published：2020-08-12 -
Star pattern recognition algorithm based SOFM clustering function
Abstract：A method that applies the clustering function of SOFM(Self-Organizing Feature Maps)network is proposed for autonomous star pattern recognition. The guide star catalog is built with the star information selected from all-sky star catalog on some guidelines. Angle distances and star model information abstracted from guide star catalog are used to train the two SOFM networks of the star pattern recognition system so that the networks have the classification and identification functions. It is concluded from the results of simulated identification that the SOFM network can reflect the complicated information among star pattern better and it appears more robust with respect to noise than conventional methods. The effect of classification is so good that it can differentiate all kinds of star models clearly and the speed of identification is so fast that it can recognize a star pattern within 1.5 ms. Therefore, it can be well applied for star pattern recognition.Keywords：star pattern recognition;SOFM network;guide star catalog;neural network- 94
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Published：2020-08-12
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