The axial compact fixing position of the optical element is mainly carried out in the form of tightening the compression ring in the optical lens assembly process. Most of the existing compression ring tightening methods use forceps and other general press ring tightening tools, the degree of tightening of the pressure ring when used mainly depends on the experience and feel of the assembler, cannot quantify the compression ring tightening torque. In order to solve the above technical problems, the research topic of optical lens compression moment quantification process technology is proposed. Based on the principle of strain sensor, a special digital explicit compression moment device was successfully developed. According to the mass production project of XX optical lenses, the test scheme of the tightening moment of each lens press is designed, and multiple compression ring tightening tests are carried out using a special digital explicit compression moment device, and the corresponding change relationship between the compression moment range of the whole lens and the lens surface type (RMS) is summarized. According to GB/T 34516-2017 "Spacecraft Vibration Test Method", the random vibration test method in the vertical direction of "sweep-vibration-sweep frequency" was used to complete the compression moment tightening performance and reliability verification. The test results are shown that the characteristic sweep curve of the optical lens before and after the vibration has not changed, the modality has always remained stable, the lens shape (RMS) remains unchanged, the optical lens is not loosened, the digital explicit compression moment device developed meets the technical requirements of the optical lens assembly process, and the compression ring tightening torque is quantified, which further improves the assembly quality reliability and assembly efficiency.
Aiming at the problem of abnormal sound of lens caused by incomplete tightening of pressure coil after optical lens installation, this paper presents a method for calculating and verifying the tightening moment of pressure coil. According to the mechanical dimension of the screw thread of the pressing ring, the mechanical properties of the pressing ring of the mirror tube and the optimal number of turning rings were calculated and analyzed. In order to meet the practical application requirements, the tightening moment of the pressure coil obtained by the solution was brought into the 3D model for simulation, and the finite element modeling analysis of the tightening moment of the pressure coil of the optical lens was completed, so as to further solve the displacement variation of the lens group. Finally, the above analysis results were quantified by torque wrenches, and random vibration was carried out at one third of the order of acceptance level vibration test conditions, so as to complete the bottom analysis and verify the tightening torque of the screw ring under different ratios of XM-31 adhesive and vulcanizing agent. The experimental results show that the characteristic sweep curve of the optical lens does not change before and after the vibration, the mode of the optical lens remains stable all the time, and the data modal analysis results are consistent with the actual situation.
Zoom CAM curve is an important part of the optical system imaging. The processing accuracy of the curve directly affects the image clarity and consistency of the optical system. In this paper, a high precision measuring device for zoom CAM curve is designed, and an optimization method of testing results is adopted. According to the curve of the CAM rotation Angle and the number of teeth on the surface of the cylindrical, with mesh number as the sample size, relative to the CAM follower parts through the grating ruler curve of linear displacement measurement and corresponding data fitting. The regression analysis method is adopted to analyze the measurement results of the grating ruler based on the detection of the altimeter, and the regression equation is obtained and modified to optimize the measurement fitting data, so as to finally improve the detection accuracy of the zoom CAM curve. The confidence interval of machining accuracy based on grating ruler CAM curve is analyzed and evaluated by an example. The results show that the zoom CAM curve detection device and result optimization method proposed in this paper have the characteristics of high accuracy, high stability and easy realization.
Compared with visible light imaging systems, the infrared imaging systems have the advantages of strong fogging ability, especially in the high-altitude water vapor and haze environment. and the medium-wave infrared cooling detectors have the advantage of low cost compared to long waves. Therefore, in recent years, The demand for medium-wave infrared continuous zoom systems is increasing. In this design, based on the medium-wave infrared optical system, and summarizing the advantages and disadvantages of the previous zoom structure, a zoom mechanism in the form of a cam and guide was proposed. The cam mechanism, zoom guide mechanism, and compensation guide mechanism were described in detail in this paper. The detailed analysis of the torque demand during zooming was performed. Ansys workbench was used to analyze the main components of the zoom mechanism and the stray light of the system was proposed. The adjustment results show that this kind of structure can realize medium-wave infrared continuous zooming, and the the amount of optical axis shaking during zooming is less than 0.3mrad, which meets the design requirements, and the proposed stray light suppression method effectively suppresses the system's spurious radiation and improves the lens's imaging quality; impact and vibration simulation show that the strength and stiffness of the structure meet the requirements of the mechanical environment, and the imaging system has stable performance.
Zoom cam is a pivotal part used for driving every lens group in zoom lens , the design result of cam curve is decisive importance for motion property and system precision as well as system imaging in zoom system, therefore, zoom cam design is an important part of the zoom lens design, a fine cam performance is the basic requirements to reach lens design of image quality goal and optical zoom process. a new method is presented in this article, it adopts the method of piecewise processing to establish several common functions in steep interval so as to make the arc length non-uniform and to segment the arc length equally in the smooth curve. The initial cam curve of an optical system is optimized and analyzed, the results show that when the arc length is divided by the power function, the cam curve can be significantly improved, the pressure angle of the curve can be reduced, and the optimized curve is smooth and without inflection point, which can effectively improve the overall performance of the cam.
A high-speed double delta sampling (DDS) circuit with pipelined structure for CMOS image sensor (CIS) is presented. Considering the low readout speed of the DDS circuit compare with correcting double sampling (CDS) circuit, We separate the main operation of DDS circuit into two steps, and run the two steps alternately in odd readout column and even readout column, which seems like the pipelined operation. Thus, the readout speed of the DDS will as twice as fast than the traditional DDS. The architecture and readout sequence of the new circuit are introduced in detail. Meanwhile simulation results indicate the proposed circuit can achieve a high speed performance.
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