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Issue 1 ， 2001
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Fully compliant mechanisms and MEMS
Abstract：Compliant mechanisms are devices that deliver a desired motion by undergoing elastic deformation. A typical compliant mechanisms is called fully compliant mechanism. Owing to their serveral significant advantages relative to conventional mechanisms such as no backlash and friction, and no assembly, compliant mechanisms especially fully compliant mechanisms have been applied to many fields especially in MEMS. So research on compliant mechanisms and fully compliant mechanisms has been a hot issue in recent years. This paper firstly describes their concepts, characteristics and applications in MEMS. Finally several critical techniques and tendencies such as the analysis, design and fabrication of fully compliant mechanisms, selection and design of flexure hinge, selection, desgin and control of the actuator etc. are discussed.Keywords：compliant mechanism;fully compliant mechanisms;flexure hinge;MEMS- 60
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Published：2020-08-12 -
Application and development of high power diode-pumped solid-state laser
Abstract：Based on the advantages of diode-pumped solid-state laser(DPSSL) over others, the trends that DPSSL advances towards high power and would take over other lasers were pointed out. The wide application fields, as well as the bright market future of high power DPSSL were also introduced. Some successful schemes for obtaining high power output were analyzed in detail. It's very important to do research on high power DPSSL as soon as possible for our country.Keywords：diode-pumped;solid-state laser;high power- 79
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Published：2020-08-12 -
Comparison of periodic subwavelength structure and multilayer antireflection coatings
Abstract：To solve the Fresnel reflection which exits generally in optical systems, we designed and analyzed one kind of structures, subwavelength surface-relief periodic structures, which have three-dimension profile, using the coupled wave method. Then comparing the calculated results with the characteristics of multilayer antireflection coatings, it was found that this subwavelength periodic structure is far more efficient than multilayer antireflection coating in a wide wave band, particularly in infrared wave band, and the reflection ratio can be controlled in 0.2% in general. Besides this, the variety of reflection of this subwavelength periodic structure can be maintained in 1% when incident angle of incident wave has a 40? deflection, while for multilayer antireflection coatings, it just can do this in 30?.Keywords：coupled wave method;subwavelength structure;multilayer antireflection coatings- 49
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Published：2020-08-12 -
Focused spot shaping in laser writing system
Abstract：The diffractive optical elements (DOE) with shaping the focused spot for laser writing system are designed, while discussing their performances for shaping laser writing spot. An efficient way of using a DOE to shape the laser writing spot under the objectives with various focal lengths is presented. The simulating results indicate that the spot-shaped sizes is only more twice than the diffraction limited spot sizes under this system, its diffraction efficiency is about 71.38% and the edges of the uniform area become dramatically sharper than the result without DOE.Keywords：laser writing;beam shaping;DOE- 38
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Published：2020-08-12 -
Laser television with two-beam scanning
Abstract：The design and priciples of a laser television with two-beam scanning are described. The system employs 2 laser beams, each being composed of red, green and blue components. The two beams from one scanner are scanned simultaneously by a rotating polygonal mirror for horizontal deflection and by a galvanometer for vertical deflection. Compared with conventional signal-beam scanning, the new design has the following advantages:(1)The rotational speed of the polygonal mirror can be reduced by a factor of 2, which will improved the system performance and decrease the difficulty of the manufacture of the system. The size of the polygonal facet and,therefore, the laser beam diameter can be increased, which will decrease the pixel diffusion. (2)The simultaneous operation of the 2 modulators will improve the horizontal resolution by a factor of 2.(3)for the same screen brightness, the single pixel power density can be reduced by a factor of 2, which will decrease the hazardous laser radiation.Keywords：laser television;laser display;scan;polygon- 52
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Published：2020-08-12 -
Electronic interface circuit design and implement with CPLD in the mobile atmosphere laser communication system
Abstract：In order to satisfy the requirement of battlefield communication, the method using laser-air communication as a way of relaying the telecommunication was used to resist wireless disturbance.The electronic interface circuit was the key part of designing. The design method of electronic interface circuit and implement with CPLD for laser-air communication system was studied. The idea of entity design, the requirements of interface, the difficulties of system design and the corresponding solutions were deeply analyzed. The new ideas about code-rate adjusting and frame synchronization grasping were presented.It also gave the implement circuit with CPLD. This interface circuit worked very well in the laser-air communication system. This method could also be used as a reference of designing for serial communication system.Keywords：serial communication;synchronization grasping;code-rate adjusting- 40
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Published：2020-08-12 -
Experiments on testing range-finding properties of laser range finder under lower temperature circumstance
Abstract：The experimental designs and the characteristics of a laser range finder under -40℃ circumstance were investigated with ITO optical windows heated to keep observation from dew or hoarfrost at room temperature. Primary experimental results and data of laser range finder in low temperature circumstance were accumulated and discussed. To meet the demands of the performance inspection of the laser range finder in working condition, the designs of ITO windows set up on a low temperature cabinet, are used to confirm the quality inspection and calibration of the laser range finder before its leaving from factory.Keywords：ITO ranging window;low temperature laser ranging;laser range finder- 52
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Published：2020-08-12 -
Method for compression and error control of a special picture
Abstract：Aiming at the problems in lossless compression and storage of an image in the actual work, this paper presents a compression method based on run-length lossless encoding and an error control coding method applied to the special image in fixed dimension and with high redundancy. Features of the problem were introduced briefly. The possibility of applying several image compressing and coding methods to the problem was discussed. A special compression method, similar to JEPG compression coding and a simple two dimensions odd-even error control method, was applied to the coding practice. This method was analyzed simply and the coding result was given. The method presented in this paper has merits as: high efficiency, rapid access, simplicity and practicality, and high reliability.Keywords：lossless compression;error control;run-length coding- 44
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Published：2020-08-12 -
Design on the focusing mechanism of space remote-sensing camera
Abstract：The focus plane of a space remote-sensing camera will decenter and defocus, to some extent, under the condition of space environment, which is changeable and complicated. A focusing mechanism is described in which precision spherical guide ways and cam guide mechanism are employed in order to meet the requirement of image quality of a space remote-sensing camera. The principles of choosing the project of focusing mechanism are introduced. The composition and working principles of this focusing mechanism, the design idea of its motion transition and the technical measures to improve its safety and reliability are stated. The result of precision analysis is presented.Keywords：spherical guide ways;cam guide mechanism;focusing mechanism;imaging quality- 52
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Published：2020-08-12 -
Image distortion calibration of IR electroviewer
Abstract：The reasons of an image distortion from infrared electroviewer are analyzed and a calibration model is set up for the nonlinear distortion. The model can be used in any imaging system which has a nonlinear radial distortion. The experimental result of calibrating the image distortion for the IR electroviewer is shown in this paper, the maximum position error is less than 1 pixel. The model can be expanded and grafted.Keywords：image distortion;nonlinear calibration;IR electroviewer- 43
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Published：2020-08-12 -
Computer post-processing method for blocking-artifact in satellite decoded images
Abstract：BDCT has been widely used for International Standard of image compression and achieved effective result. However, there exists blocking-artifact problem in loss decoded image processing. In order to reduce satellite image blocking-artifact, the improved blocking-artifact post-processing algorithm based on DCT post-processing method[4] has been proposed, according to the characteristic of the satellite image. The algorithm can not only reduce the blocking-artifact and improve the image quality, but can also save the post-processing time for DCT blocking-artifact and improve the efficiency. This algorithm is extensively useful.Keywords：BDCT;decoded image;satellite image;image post-processing- 44
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Published：2020-08-12 -
Threshold selection method for medical X-ray images filter based on minimum even-square error
Abstract：Disturbance noises in medical X-ray imaging systems consist of inherent and quantum noises, which obey random Gauss and Polsson distributions, respectively. This paper theoretically provided an optimum threshold selection method for medical X-ray images filter. Through practical process of CT images, medical X-ray images filter based on minimum even-square error has been accomplished in this work.Keywords：medical X-ray images;removal of noises;filter threshold;wavelet transformation(WT)- 76
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Published：2020-08-12 -
Theoretical study of the intensity dependence of two-beam coupling gain coefficient in photorefractive crystals
Abstract：Intensity dependence of the two-beam coupling gain coefficient Γ, the effective trap density Neff and the intensity dependent factor η(I) is studied theoretically for the two-centre photorefractive crystals. The results show that Neff, η(I) and Γ have more complicated behaviors in two-centre crystals. When S DγT/S TγD is small, Neff increases and tends to saturate with increasing intensity for both type-A and type-B two-centre crystals. When S DγT/S TγD is large, Neff increases to a maximum and then decreases a little for type-A crystals and decreases greatly for type-B crystals.The different intensity dependence of Γ in the two types of crystals comes from their different level structures.Keywords：photorefractive crystals;two-wave coupling;gain coefficient;intensity dependence.- 82
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Published：2020-08-12 -
Optical trap steering system
Abstract：An optical tweezers, which can be used to mainipulate biological sample in three dimensions, was incorporated into a LEICA DMIRBE inverted microscope with bottom port. During setting up this system, transverse position mainpulating system of an optical trap was studied especially. Theoretical analysis and experimental results indicate that the transvers position of an optical trap can be changed by laterally moving or rotating a mirror. The mechanisms of optical trap steering systems by moving and rotating mirrors were explained in detail, respectively. In addition, comparing with moving mirror system the rotating mirror system is of benefit to increase the mainipulating speed of an optical trap, simplify the mechanism of an optical tweezers, reduce its cost, and shorten the cycle of completing an optical tweezers.Keywords：optical trap steering system;optical tweezers;optical trap- 41
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Published：2020-08-12 -
Harmonic analysis of PZT bimorph actuator for microrobot
Abstract：The PZT bimorph actuator for microrobot, which is suited for inspecting the pipe of φ20mm diameter were studied. The actuator is made of PZT bimorph, center shaft and mass. With different boundary conditions of bimorph, the response at the first mode natural frequency of actuator were analyzed. FEM( finite element method) were used. The conclusion can be reached that when the fixing degree is 9° or 63°, the response is larger than those of others. All these are the theoretical basis of optimization of this kind of microrobot.Keywords：bimorph;microrobot;actuator;harmonic analysis- 58
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Published：2020-08-12 -
A novel 6-SPS spherical platform parallel robotic mechanism and analysis of its local properties of force and motion transmission
Abstract：The design of a novel 6-SPS spherical platform 6-DOF orthogonal parallel robotic mechanism is presented. The layout feature of the mechanism is described. Its local properties of the force and motion transmission and the relationships between the properties and the link lengths are studied, which provides theoretical base for the optimal design and application of the mechanism. From the analysis of the results obtained by us, it is shown that its properties of the force and motion transmission are characterized by isotropy at the orthogonal configuration. The mechanism is particularly suitable for certain applications in 6-DOF micromanipulators and 6-axis force/torque transducers.Keywords：6-DOF parallel robotic mechanism;spherical platform mechanism;orthogonal configuration;isotropy.- 72
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Published：2020-08-12 -
Flexure hinge in beam line of synchrotron radiation
Abstract：The movement equations of right circular flexure hinge is derived, which are the angular deflections due to the torques and linear deflections due to the forces; the material selection of right circular flexure hinge in synchrotron radiation and the design for the parameters of the flexure hinge are analyzed; the adjustment frame of yaw, pitch and roll in monochromator of synchrotron radiation based on the right circular flexure hinge are introduced.Keywords：flexure hinge;monochromator;synchrotron radiation- 53
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Published：2020-08-12 -
Computer-controlled compensation for wearing of polishing head
Abstract：The wearing of the die is an important factor to the computer-controlled optical surfacing(CCOS). But in actual work, process can not be interrupted to adjust the zero and the wearing of the polishing head can not be compensated on real-time. So an exponential function is put forward to compensate the wearing of the head. The Preston function is modified according to this theory. The constant of the function is also determined by our experiment. This method is introduced into the polish process and the materials' error correction. With this method, the ratio of precision of the CCOS is improved.Keywords：optical polishing;computer-controlled optical surfacing(CCOS);wearing;computer-controlled compensation- 83
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Published：2020-08-12 -
Deduction of the transfer function of speed measuring in digital mode realized by position differential
Abstract：The transfer function of speed measuremet realized by position differential in digital mode affects the controller's effects directly when design the controller in continuous system method. Through deduction and emulation verification, this paper shows that the transfer function of speed measurement realized by position differential in digital mode is equal to a combination of a differential part and an inertia part, and it is more reasonable than to a pure delay part in reference 2 and 3. And also the engineering condition that the transfer function of speed measuring realized by position differential in digital mode is equal to a combination of a differential part and an inertia part is offered.Keywords：position differential;speed measuring in digital mode;transfer function- 43
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Published：2020-08-12 -
Optimal parameter analysis of optical fiber digital communication detection circuit
Abstract：Optical fiber communication technique has wide application. This paper introduces the structure and principle of optical fiber communication system, makes the systematic analysis about optical fiber communication's opto-electronic signal,noise of the detection circuit,S/N,minimum-detection ability and amplitude discriminator's threshold value. The reliable base of design for coherent parameter is provided. Experimental results show that this paper has important value for single laser pulse detection system.Keywords：optical fiber;digital communication;detection circuit;noise threshold value;parameter analysis- 53
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Published：2020-08-12 -
Measurement and compensation for refractive index of air using a pre-evacuated airtight sealed cavity
Abstract：The compensation effect for refractive index of air is the "bottle neck" factor in improving the accuracy of interferometric measurement. The theory of compensation for refractive index of air is analyzed. Several methods for measuring refractive index of air are analyzed and effectiveness of compensation is compared. Based on these results, an interferometric device to measure the refractive index of air without air evacuation in the measuring process is studied. A pre-evacuated airtight sealed chamber with 45皊lope is employed. It is testified that the method is effective and the measuring accuracy is improved by the experiments of measuring and compensating for refractive index of air.Keywords：interferometry;refractive index of air;compensation- 41
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Published：2020-08-12 -
A new digital angle measurement technology by using Malchlson interferometer and its application
Abstract：A precise angle measurement system was presented based on Malchlson interferometer technology. This system took advantage of the Malchlson interferometer measurement technology used in the geometrical sense measurement and realized the exact measurement towards the big angle by changing the angle displacement to line displacement and using special circuits to subdivide and measure the interference pattern. This system has several merits such as high measurement precision, wide angle range and high digitialization compared with the other similar systems. The principle of the system and the matters should be pard attention to when design this system were prsented,also, precision analysis about the system was given.Keywords：Malchlson interferometer;laser;angle;measurement- 55
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Published：2020-08-12 -
Device driver programming in Windows NT for PCI data acquisition card
Abstract：The Microsoft Windows operating system insulates the application programmer from dealing with hardware directly. So it is difficult for image processing on real time,such as acquisition,storage and display. This paper studied Kernel mode of Windows NT, and discussed the routine of interruption and DMA,then a device driver program was designed to solve this problem.The method of VDD has a wide application prospect and practical value in real time image processing.Keywords：Windows NT;Kernel mode;interruption;DMA;virtual device driver- 41
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Published：2020-08-12
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