Topic
Infinity focus
About: Infinity focus is a research topic. Over the lifetime, 1302 publications have been published within this topic receiving 17201 citations.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: In this paper, a two-dimensional microwave lens with a straight front face was used to generate fractional degree beams, which can operate at very short pulse lengths and can scan more beamwidths than any previously known device of its type.
Abstract: A new "time-delay" scanner consists of a constrained wide-angle two-dimensional microwave lens with a straight front face in which lens elements connect arbitrary points on the inner and outer contours. The lens can operate at very short pulse lengths and can scan more beamwidths than any previously known device of its type. A phase analysis shows that this design has very small coma aberrations and that the lens can generate fractional degree beams. Criteria developed for selecting optimum lens parameters are given. The radiation patterns of an experimental model in which the lens elements consist of coaxial cables show the expected wide-angle characteristics. In further tests incremental scanning was obtained through the use of phase shifters in the coaxial lens elements. The design of symmetrical three-dimensional lenses is briefly discussed. A table of lens contour parameters is given for an optimum lens design with scan angle \alpha of 30\deg .
843 citations
Patent•
21 Aug 2009
TL;DR: In this paper, a small-sized five-element image pickup lens with a sufficient lens speed of about F2 and exhibits various aberrations being excellently corrected is presented.
Abstract: Provided is a small-sized five-element image pickup lens which ensures a sufficient lens speed of about F2 and exhibits various aberrations being excellently corrected. The image pickup lens is composed of, in order from the object side, a first lens with a positive refractive power, including a convex surface facing the object side; a second lens with a negative refractive power, including a concave surface facing the image side; a third lens with a positive or negative refractive power; a fourth lens with a positive refractive power, including a convex surface facing the image side; and a fifth lens with a negative refractive power, including a concave surface facing the image side. The image-side surface of the fifth lens has an aspheric shape, and includes an inflection point at a position excluding an intersection point with the optical axis.
220 citations
Patent•
12 Feb 2008
TL;DR: An optical lens system for taking image comprises, in order from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface; an aperture stop; a second lens elements with negative refractive powers; a third lens element having a concave object side surface; and an image side surface of the fourth lens element being aspheric and formed with inflection points.
Abstract: An optical lens system for taking image comprises, in order from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface; an aperture stop; a second lens element with negative refractive power; a third lens element having a convex object-side surface; and a fourth lens element with negative refractive power having a concave object-side surface, an image-side surface of the fourth lens element being aspheric and formed with inflection points. A distance from the image-side surface of the fourth lens element to an image plane along an optical axis being BFL, a total track length of the optical lens system for taking image being TTL, and they satisfy the relation: BFL/TTL>0.12. In the optical lens system for taking image, the number of lens elements with refractive power being limited to four.
214 citations
Patent•
[...]
31 Mar 2003
TL;DR: A single focus lens as mentioned in this paper consists of a positive power lens with a convex-shaped surface on an object side, a negative meniscus lens with concave surface on its paraxial axis, and a third lens of an aspheric lens having convex shape on its surface on the object side.
Abstract: A single focus lens comprises: a first lens of positive power having a convex-shaped surface on an object side; a second lens of a negative meniscus lens having, on the object side, a concave-shaped surface on its paraxial axis; and a third lens of an aspheric lens having, on the object side, a convex-shaped surface on its paraxial axis, in this order from the object side, wherein the single focus lens satisfies the predetermined conditions.
211 citations
Patent•
14 Dec 2011TL;DR: In this paper, a zoom lens system with negative power, positive power, negative power and positive power was presented, where the first lens group, second lens group and third lens group move along the optical axis.
Abstract: This zoom lens system is provided with: a first lens group that has negative power; a second lens group that has positive power; a third lens group that has negative power; and a fourth lens group that has positive power. During zooming, the first lens group, second lens group, and third lens group move along the optical axis. During focusing, the third lens group moves along the optical axis. The zoom lens system satisfies the conditions: 2.5 ≤ | (1 - (β 3T ) 2 ) × (β 4T ) 2 | ≤ 7.0 and 0.5 ≤ Bf W /f W ≤ 4.0 (β 3T being the lateral magnification of the third lens group at an infinite object distance at the telephoto end; β 4T the lateral magnification of the fourth lens group at an infinite object distance of the telephoto end; Bf W the back focus of the entire system at the wide angle end; and f W the focal length of the entire system at the wide angle end).
198 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 3 |
| 2018 | 1 |
| 2017 | 5 |
| 2016 | 12 |
| 2015 | 28 |
| 2014 | 36 |