Homogeneous optimization approach for reducing sensitivity of an optical lens system
TL;DR: The proposed sensitivity optimization method can homogenize image performance for the same field under different tolerance values and improves the product yield rate by 15 to 17% compared with a traditional optimization method.
Abstract: During the production of a lens system, the assembling and manufacturing tolerances must be accurately controlled to ensure production efficiency. Thus, it is important to analyze and optimize the tolerance sensitivity of the lens system during the optical design phase to reduce optical performance degradation. We proposed an approach for appropriately controlling the tolerance sensitivity of a lens system. The proposed sensitivity optimization method can homogenize image performance for the same field under different tolerance values. Based on the results, we show that the implementation of the proposed method sharply reduces sensitivity and, consequently, improves the product yield rate by 15 to 17% compared with a traditional optimization method. As a practical example, a 40-megapixel f1.8 mobile phone camera lens design and optimization process was performed in our study. Our preliminary experimental results confirm that the proposed method is effective to reduce the optical sensitivity of the camera lens.
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TL;DR: Effective alternatives are presented for working with rotationally symmetric surfaces that are either (i) strongly aspheric or (ii) constrained in terms of the slope in the departure from a best-fit sphere.
Abstract: Advances in fabrication and testing are allowing aspheric optics to have greater impact through their increased prevalence and complexity. The most widely used characterization of surface shape is numerically deficient, however. Furthermore, with regard to tolerancing and to constraints for manufacturability, this representation is poorly suited for design purposes. Effective alternatives are therefore presented for working with rotationally symmetric surfaces that are either (i) strongly aspheric or (ii) constrained in terms of the slope in the departure from a best-fit sphere.
190 citations
04 Jun 2006
TL;DR: In this paper, a method of using global synthesis for finding tolerance-insensitive systems is described, by altering the merit function to include information that prefers less sensitive solutions, the space of toleranceinsensitive design configurations may be explored.
Abstract: A method of using Global Synthesis™ for finding tolerance-insensitive systems is described. By altering the merit function to include information that prefers less sensitive solutions, the space of tolerance-insensitive design configurations may be explored.
46 citations
04 Jun 2006
TL;DR: In this article, a global optimization method was developed that takes into account the robustness of the lens with respect to manufacturing errors as well as its image quality, and a technique called ''Θ-segmentation'' was proposed.
Abstract: A global optimization method was developed that takes into account the robustness of the lens with respect to manufacturing errors as well as its image quality. We propose a technique called 'Θ -segmentation'.
39 citations
TL;DR: Effective approximations can be exploited when an asphere's shape is characterized by using a particular orthogonal basis, and are used not only as quick manufacturability estimates at the production end, but more importantly as part of an efficient design process that can boost the resulting optical systems' cost-effectiveness.
Abstract: Some simple measures of the difficulty of a variety of steps in asphere fabrication are defined by reference to fundamental geometric considerations. It is shown that effective approximations can then be exploited when an asphere’s shape is characterized by using a particular orthogonal basis. The efficiency of the results allows them to be used not only as quick manufacturability estimates at the production end, but more importantly as part of an efficient design process that can boost the resulting optical systems’ cost-effectiveness.
35 citations
TL;DR: This work proposes using the Hessian as part of a cost-based tolerancing procedure for optical systems, and demonstrates the utility of this approach by way of an example.
Abstract: When designing an optical system it is generally accepted that it is too costly to generate the entire Hessian for every iteration of an optimizer. However, the Hessian also is useful in tolerance analysis for which it needs to be calculated only once. We propose using the Hessian as part of a cost-based tolerancing procedure. Considerations for the general implementation of the proposed ideas are discussed, and the utility of this approach is demonstrated by way of an example. In the example optimal manufacturing tolerances are determined for a doublet. As expected, the optimal tolerances change as quantities such as the requisite image quality for finished systems, manufacturing yields, and relative expenses of meeting given tolerances are varied.
28 citations
"Homogeneous optimization approach f..." refers background or result in this paper
...i1⁄41 ðSi_positive − Si_negativeÞ∕S̄; (2)...
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...(2) can be extracted using macro language and buff commands....
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...(2)] for the two optimization systems compared in our study....
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...Thus, the corresponding function of merit (FOM) is defined as follows: EQ-TARGET;temp:intralink-;e002;116;545goal ¼ Xk i¼1 ðSi_positive − Si_negativeÞ∕S̄; (2) where i is the i’th field that need to be tested, Si_positive is the Strehl ratio of i’th positive field, Si_negative is the i’th negative field, and Si is the average Strehl ratio of the i’th positive and negative fields....
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...(2), an optical designer can decrease tolerance sensitivity efficiently....
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