共查询到20条相似文献,搜索用时 31 毫秒
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用步进电机实现连续变焦距光学镜头的变焦控制 总被引:7,自引:0,他引:7
根据望远镜的工作原理,对变焦距光学镜头的变焦运动进行了定性分析,并且根据理想光学系统的物像关系式推导出该镜头运动镜组的运动方程。该连续变焦控制的实验装置包括步进电机,电机驱动器以及控制平台,其控制程序用VisualC 编写。实验表明,该方法能方便地实现连续变焦距光学镜头的变焦控制。 相似文献
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In this study, an optical zooming design method is constructed by ray tracing. The loci of each thin lens is determined utilizing algebraic relationships. A mechanical compensation structure is adapted to stabilize the position of the focal plane. The Gaussian design result is applied for the midwave infrared spectrum, and aberrations can be reduced by controlling the geometric parameters of the thick lens. One hybrid achromatic singlet is introduced utilizing a diffraction optical element. The kinoform surface relief is calculated being the same as its microfabrication process. The effects of the discontinuous zonal profile and the thermal degradation are evaluated. 相似文献
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Khoury J Woods CL Haji-saeed B Pyburn D Sengupta SK Kierstead J 《Applied optics》2006,45(27):6897-6902
We propose an optical corrective element with zooming capability to convert nonlinear sinusoidal scanning into linear scanning. Such a device will be useful for linearizing the angular scan of a resonant mirror scanner. The design methodology is to create a graded index of refraction device as the reference design, with its index of refraction parameters based on the propagation of an electromagnetic field in inhomogeneous media. The algorithm for converting this refractive element to the corresponding binary diffractive version is also presented. Design and simulation data are shown. 相似文献
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Chao-Hsien Chen 《Journal of Modern Optics》2013,60(1):105-126
A general algorithm is proposed for evaluating variations of primary monochromatic and chromatic aberrations of single surface or thin-lens components when the paraxial marginal and chief rays are arbitrarily moved. Compared to the earlier algorithm, optical invariants of the original and the new optical configurations could be different, which is common when the object distances are changed or for zoom lenses with different f-numbers on zooming. According to the positions of object and pupil, four special cases arise which lead to the need for four separate sets of coefficients, and a new parameter which is always determinate is used to indicate which set is to be chosen. 相似文献
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Itio Hirai Bo Ping Wang Walter D. Pilkey 《International journal for numerical methods in engineering》1984,20(9):1671-1683
In this paper, an efficient, exact zooming technique is developed which employs static condensation and exact structural reanalysis methods. For a multiple level of zooming such that the successive level of zooming is contained within the prior levels of zoom, repeated application of static condensation will reduce the system to one that is associated only with the degrees-of-freedom (dof) of the original model. Then, application of an exact static reanalysis technique permits the displacements at the dof of the original model that are contained in the final zoomed portion of the structure to be obtained first. Next, the response external to the zoom, as well as the response of additional dof within various levels of zooming, can be computed. With the triangular factor of the stiffness matrix of the original system available, this approach involves only the solution of a system of equations of small order. The proposed method is demonstrated by a numerical example. 相似文献
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针对机械式衍射光栅刻划机精密定位工作台定位过程中产生的振动信号特性与光学性能指标(杂散光强度和波前质量)之间的关系,提出利用改进的Hilbert-Huang变换(HHT)获得的时频谱和边际谱对超精密工作台精定位特性进行研究。首先,给出了基于固有模态函数(IMF)筛选和瞬时频率差分求解的HHT信号处理算法。然后,设计了光学测量实验获得工作台50nm定位信号。最后,完成精密定位信号的特征提取和振动测试验证。结果表明:利用改进的HHT可以精确地完成精密定位信号的特征提取,从而为在衍射光栅的制造工艺中从根源上降低衍射光栅的杂散光强度和提高波前质量提供依据。 相似文献
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Khoury J Haji-saeed B Morath CP Woods CL Sengupta SK Kierstead J 《Applied optics》2006,45(32):8177-8185
A new approach for designing diffractive optical corrective elements with zooming capability to convert nonlinear sinusoidal scanning into linear scanning is proposed. Such a device will be useful for linearizing the angular scan of a resonant mirror scanner. The design methodology is to create a graded index of a refraction device as the reference design with its index of refraction parameters based on beam retardation through propagation in an inhomogeneous medium. The diffractive element is designed by utilizing a binarizing algorithm of the accumulated phase from transmission through the refractive element. In contrast to a prior approach, which was introduced based on the beam propagation through inhomogeneous media, the new approach takes beam diameters into consideration. This makes both the refractive element and its associated diffractive element more robust against beam fanning. 相似文献
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目的 解决光学定位技术在引入肌肉痉挛治疗的注射手术应用中,光学定位设备与现有医用超声仪器之间的不适配问题,旨在进一步提升理论定位精度稳定性,简化必需操作并降低实际应用难度。方法 在现有超声仪及相关设备功能基础上,结合光学定位设备工作条件需求进行需求分析,重新构建产品元件功能流模型并映射为网络节点,并基于复杂网络节点重要度评价方法,确定目标产品设计重心点并分层设计,最后采用仿真验证测试设计合理性。结果 实验结果符合预期假设,目标节点所对应功能元件与其它节点的相关性程度与目标元件所需兼容连接的复杂度呈正相关。基于实验得出能够适配光学定位仪与超声设备的设计方案,有效解决二维超声导航引导肌肉注射所面临的不直观、不可视等问题。结论 基于复杂网络节点的重要度评价方法更适用于复杂功能产品的设计研究,评价结果重要度差异更为显著。 相似文献
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Study of a dual-frequency laser interferometer with unique optical subdivision techniques 总被引:2,自引:0,他引:2
A dual-frequency laser interferometer has been developed based on a low-performance commercial interferometer. An optical resolution of 1.24 nm and a nanometer-scale accuracy have been achieved by using unique techniques to obtain an optical subdivision factor of 1/8. A method for reducing static positioning errors was also shown. The measurement of a free-falling body was performed to test the maximum achievable target velocity of the device. The experimental setup for measuring the static positioning errors was also given. The new interferometer could be widely used in nanometer-scale fabrications and measurements. 相似文献
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Tanaka K 《Applied optics》1983,22(4):541-553
With the help of Gaussian Brackets, this paper presents a paraxial study of the mechanically compensated zoom lens which consists of a fixed front component, three independently movable components, and a fixed fifth component. The expressions, which define the displacement of components at zooming, the critical point of displacement, and the singular point of displacement are derived. Some numerical examples of the zooming locus are given. 相似文献
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Ion beam figuring (IBF) technology for small scale optical components is discussed. Since the small removal function can be obtained in IBF, it makes computer-controlled optical surfacing technology possible to machine precision centimeter- or millimeter-scale optical components deterministically. Using a small ion beam to machine small optical components, there are some key problems, such as small ion beam positioning on the optical surface, material removal rate, ion beam scanning pitch control on the optical surface, and so on, that must be seriously considered. The main reasons for the problems are that it is more sensitive to the above problems than a big ion beam because of its small beam diameter and lower material ratio. In this paper, we discuss these problems and their influences in machining small optical components in detail. Based on the identification-compensation principle, an iterative machining compensation method is deduced for correcting the positioning error of an ion beam with the material removal rate estimated by a selected optimal scanning pitch. Experiments on ?10?mm Zerodur planar and spherical samples are made, and the final surface errors are both smaller than λ/100 measured by a Zygo GPI interferometer. 相似文献
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Here we introduce a new paradigm of far-field optical lithography, optical force stamping lithography. The approach employs optical forces exerted by a spatially modulated light field on colloidal nanoparticles to rapidly stamp large arbitrary patterns comprised of single nanoparticles onto a substrate with a single-nanoparticle positioning accuracy well beyond the diffraction limit. Because the process is all-optical, the stamping pattern can be changed almost instantly and there is no constraint on the type of nanoparticle or substrates used. 相似文献
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This paper reports a new method of head positioning by applying optics to magnetic disk systems. To increase the accuracy of head positioning, several methods in which a servo disk is not used have been investigated. Until now these methods were unsuccessful because of interference between the head positioning signal and the data signal, both of which were recorded on the same data surface. In the method explained here, the head can be positioned on the disk by an optically detected positioning signal without disturbing operation of the magnetic disk system. A unique structure for both the disk and head was investigated. Optical patterns depicting position of the data tracks were formed by coloring the anode oxidized surface layer of an aluminum substrate, and by forming a magnetic film over that. Three optical fibers were imbedded in a hole in the central rail of a Winchester-type ferrite head and were used to read the optical pattern. A stable positioning signal was optically detected from the rotating disk. By using the signal to assemble a simple servo loop, the head could be positioned with ±3 μm accuracy. Potential accuracy was found to be ±0.7 μm. 相似文献
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Llobera A. Seidemann V. Plaza J.A. Cadarso V.J. Buttgenbach S. 《IEEE sensors journal》2006,6(2):412-419
The design, simulation, fabrication, and characterization of quad-beam polymer optical accelerometers is presented in this paper. An applied acceleration causes a misalignment between the waveguides that comprise the structure. Two different geometries with different beam widths have been tested. Both of them show high mechanical and optical sensitivity and negligible cross sensitivities. Self-alignment structures for fast and accurate fiber-optic positioning have also been implemented in the device. Stable, simple, and robust technology that only requires two technological steps is also presented. Static characterization shows experimental optical sensitivities of at least 15.8 and 6.2 dB/g for each optical accelerometer. 相似文献