Ultrahigh-performance long-focal-length close-focusing zoom lens for the visible waveband

1993 ◽  
Author(s):  
Iain N. Neil
Keyword(s):  
Focal Length ◽  
Zoom Lens

Design of a twenty-element long focal length zoom lens

1990 ◽  
Author(s):  
Robert M. Malone ◽  
Brent C. Frogget ◽  
David A. Grafton ◽  
Frank R. Mitchell
Keyword(s):  
Focal Length ◽  
Zoom Lens

scholarly journals Computation of Analytical Zoom Locus Using Padé Approximation

Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 581 ◽  
Author(s):  
Kang Min Kim ◽  
Sun-Ho Choe ◽  
Jae-Myung Ryu ◽  
Hojong Choi
Keyword(s):  
Rational Function ◽  
Focal Length ◽  
Padé Approximation ◽  
Analytic Form ◽  
Zoom Lens ◽  
Lens System ◽  
Depth Of Focus ◽  
Pade Approximation ◽  
Conventional Calculation ◽  
Back Focal Length

When the number of lens groups is large, the zoom locus becomes complicated and thus cannot be determined by analytical means. By the conventional calculation method, it is possible to calculate the zoom locus only when a specific lens group is fixed or the number of lens groups is small. To solve this problem, we employed the Padé approximation to find the locus of each group of zoom lenses as an analytic form of a rational function consisting of the ratio of polynomials, programmed in MATLAB. The Padé approximation is obtained from the initial data of the locus of each lens group. Subsequently, we verify that the obtained locus of lens groups satisfies the effective focal length (EFL) and the back focal length (BFL). Afterwards, the Padé approximation was applied again to confirm that the error of BFL is within the depth of focus for all zoom positions. In this way, the zoom locus for each lens group of the optical system with many moving lens groups was obtained as an analytical rational function. The practicality of this method was verified by application to a complicated zoom lens system with five or more lens groups using preset patents.

scholarly journals Four-group stabilized zoom lens design of two focal-length-variable elements

2013 ◽  
Vol 21 (6) ◽  
pp. 7758 ◽  
Author(s):  
Qun Hao ◽  
Xuemin Cheng ◽  
Ke Du
Keyword(s):  
Focal Length ◽  
Zoom Lens ◽  
Lens Design ◽  
Length Variable ◽  
Zoom Lens Design

Structural Calculation and Optimal Design of Large-Aperture Long-Focal-Length Full-Frame Zoom Lens

2019 ◽  
Vol 56 (9) ◽  
pp. 092201
Author(s):  
温林凯 Wen Linkai ◽  
刘英 Liu Ying ◽  
姜洋 Jiang Yang ◽  
邢妍 Xing Yan ◽  
孙强 Sun Qiang
Keyword(s):  
Optimal Design ◽  
Focal Length ◽  
Zoom Lens ◽  
Large Aperture ◽  
Structural Calculation

Image Quality Improvement with Liquid Field Lens Scheme in 9x Zoom Lens Intermediate Optics

2015 ◽  
Vol 764-765 ◽  
pp. 1245-1249
Author(s):  
Chih Ta Yen ◽  
Ing Jr Ding ◽  
Jyun Min Shih
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Zoom Lens ◽  
Modulation Transfer ◽  
Optical Aberrations ◽  
Optimal Method ◽  
Droplet Shape ◽  
Liquid Lens ◽  
Image Quality Improvement

This paper proposes compensation method with liquid lens as field lens in 9x zoom lens intermediate optics. According to the droplet shape and location of liquid lens which can adjust reversibly to tune the focal length and position of the lens by changing the applied voltage on the set of electrodes and hence the liquid lens can replace more lens to reduce total length size of opto-mechanics system. In the proposed field lens scheme, we use CODE V built-in optimal method to find the best liquid lens parameter versus difference zoom of intermediate optics. There are several general optical aberrations taking into consideration. Comparing with original 9x intermediate optics without field lens technology, the maximum the spherical aberration (SA), the tangential coma (TCO), the tangential astigmatism (TAS), the transverse chromatic aberration (TCA) and the petzval surface curvature (PTZ), and modulation transfer function (MTF) improved by 42.8%, 87.5%, 92.5%, 77.8%, 9.06% and 2877%.

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