Papers by Keyword: Aspheric

Abstract: For the aspheric processing is complex , time consuming and difficult to guarantte the eccentricity ,this paper introduce a new method of aspheric processing --repairing and polishing methed and describe the principle . Best fit radius, removal function were computed by mathematical model method and the respective performance curves were given by simulation. This methed has the particular advantage of shortening the working time ,reducing the eccentric amount of the element and improving the processing efficiency. Through this processing method, do a series of processing experiments on the smaller aspheric tolerance single crystal silicon aspheric.As the result indicated , plane surface shape error PV 0.52 μm,surface roughness RMS value of single-crystal silicon 0.09 μm ,the center deviation was less than1μm and the surface smoothness meet the standard above the grade Π.

Abstract: Needs of precision optical mirrors are increasing in the astronomical space telescope. In the space having extremely large temperature differences, the aspheric optical mirror made of low thermal expansion ceramic is very effective in reducing the focus errors due to the thermal expansion. In order to develop the mirror made of a new low thermal expansion ceramic, parabolic mirror of the ceramic is ground and polished to test. By the grinding and polishing test, changes of form deviation profiles and surface roughness profiles are evaluated and machinability of the proposed ceramic is studied.

Abstract: Based on the traditional aspheric surface shape measuring difficulties, a kind of new integral minimum method is presented, whose guiding idea of this method is to make right position for the parts theoretical curve and the measuring curve to sure the error sum to be minimum. The definition of integral minimum method is elaborated, for example parabolic, its surface shape error is discussed, and the right position expression is derived for the parts theoretical curve and the measuring curve. The calculating example shows that the integral minimum method is effective to analyze the real parts contour error due to the right position, so it should be a followed law objectively during the parts surface shape measuring.

Abstract: Based on the theory of multi-body system, for thetangent method CNC aspheric machine tool, the paper shows out the topologicalstructure and the array of low-order body of the system, the modeling processis stated, a specific mathematical expression for the comprehensive error modelis established, and it will be a steppingstone to the error compensation forthe machine tool.

Abstract: For tFor t For tFor the imaging advantages of aspheric optical component, it has been widely used in the aviation, aerospace, defense and civilian high-technology. Aspherical surface shape test is a key factor restricted aspheric processing and a complex sophisticated testing techniques. The well known measurement methods are faulty. Each method has advantages and disadvantages; many methods cannot be used for online testing. In this paper，the geometric principle of a swing-arm profilometer as a novel method to measure aspherics is introduced．The deviation between the actual and the ideal of aspherical surface shape is confirmed by the high-precision measurement for the vertical height with a specific path on the aspherical optical surfaces. By adjusting the location of measuring devices to maintain the distance of rotation center to the center of workpiece equal to the length of swing-arm,we can achieve the measurement for the workpiece of different machining tool. The measurement system mainly consists of the lifting and landing system of the high-precision axis,the high-precision level turntable rotary table, the high rigidity measuring arm and the high precision measurement sensors. And the follow-up data processing puts forward a number of error correction models at the same time. The advantages of the measurement method are that the measurement sports is only a simple turning motion .It will be helpful to reduce measurement errors and improve the efficiency of measurement.

Abstract: In recent years, for the compact system structure of aspheric lens, it has improved the image quality and excellent performance. More and more applications, in a variety of precision instruments, require the aspheric surface machining precision, fast, batch production. In order to further seek the effective method of aspheric surface processing, the aspheric NC machining technology is put forward. Therefore, this paper studies the aspheric surface in NC machining process of milling molding, polishing and polishing equipment related process parameters. Focusing on the milling process of various parameter settings, the resilient mold and small grinding head fixed combination method of polishing is introduced into the milling feedback compensation, solution of the elastic die polishing on the profile accuracy of destruction and processing to meet the requirements of the drawings of components: the contour measurement method on the profile accuracy of testing and surface shape accuracy of 0.5924um.

Abstract: Aspheric detection technology has always been the key factor which affects the further enhance of aspheric precision manufacturing. Without high-precision detection methods and instruments to fit processing accuracy, aspherical precision machining and ultra-precision machining is difficult to achieve. A contact measurement of aspheric surface detection technology and its error analysis are mainly introduced in this paper, and testing equipment is the UK Taylor Hubson profilometer with instrument precision 0.2μm and measure the caliber 200mm.

Abstract: The unibody of LED lampshade is the expansion of a lampshade array from single-LED in order to decrease assembly time, the forming technique is complicated. This study employ solid model to build micro mold, and find out the optimal design parameters, such as gate position, running system, cooling system and holding pressure system. The improvement of gate system can reach flowing equilibrium when molten plastic flows into cavity, and no welding line is produced. In the cooling stage, the cooling speed at each cavity is also steady and balance in order to reduce residual stress and lens defects. This study utilizes multi-gate system and multi-stage holding pressure aided forming to decrease welding line and residual stress. This study improves traditional mold design to fit more multi-cavity LED mold design which includes cooling system redesigning, cavities layout, flowing balance in runner and reducing shear stress. The Taguchi method and orthogonal array are used in the study for each group of experiment; many factors are applied to obtain the minimum shear stress, minimum warp, reduction of flow mark and uniform stress distribution. The results can provide for industry reference.

Abstract: We composed optical system which is made of two optical lenses, beam expander, and Laser Diode(LD). When the light from the LD pointed to the remote moving object, we optically aligned to achieve full power performance in the given angle range. We also reviewed optical design data with Light Tools, and measured some factors including LD cell, surface roughness and refringence. The result shows that the laser point source optical system displayed good uniform power shape, and the LD used for this experiment to be guaranteed superior output power performance compared to conventional specifications.

Abstract: The error compensation is an essential issue for improving the accuracy of the machining process. To solve the error compensation for parallel grinding of the noncoaxial aspheric lens, a kinematics model of six-axis ultra-precision machining system has been developed in the present study. Based on the theory of multi-body system, a kinematics errors analysis is presented. The interpolation errors of the parallel grinding method are discussed according to the kinematics errors analysis. Simulation results show that the rotation errors of the grinding system are crucial factors affecting the accuracy of the machining process.