Zoom lens

About: Zoom lens is a research topic. Over the lifetime, 9327 publications have been published within this topic receiving 70804 citations.

Visual attention within and around the field of focal attention: A zoom lens model

Abstract: The operation of attention in the visual field has often been compared to a spotlight. We propose that a more apt analogy is that of a zoom or variable-power lens. Two experiments focused upon the following questions: (1) Can the spatial extent of the attentional focus be made to vary in response to precues? (2) As the area of the attentional focus increases, is there a decrease in processing efficiency for stimuli within the focus? (3) Is the boundary of the focus sharply demarked from the residual field, or does it show a gradual dropoff in processing resources? Subjects were required to search eight-letter circular displays for one of two target letters and reaction times were recorded. One to four adjacent display positions were precued by underlines at various stimulus onset asynchronies before display presentation. A response competition paradigm was used, in which the “other target” was used as a noise letter in noncued as well as cued locations. The results were in good agreement with the zoom lens model.

Optical scanner for reading and decoding one- and-two-dimensional symbologies at variable depths of field including memory efficient high speed image processing means and high accuracy image analysis means

Abstract: An optical device for reading one- and two-dimensional symbologies at variable depths of field. The device has a light source for projecting emitted light toward the symbol image to be reflected back to an optical assembly, or zoom lens. The zoom gives multiple field of view capability to a CCD detector for detecting the reflected light, and generating a proportional electrical signal. The sensor is aimed for reading the symbology by a frame locator including a light source that emits a beam divided by diffractive optics into beamlets matching the dimensions of the respective field of views. Refractive optics are shifted in response to movement of the zoom lens for aiming the beamlets to form an aiming frame in accordance with the depth of field selected by the zoom lens. The device includes a microcomputer that communicates with a host PC including an API library with downloadable applications for image processing, including segmenting, analyzing, and decoding.

Tunable Metasurface and Flat Optical Zoom Lens on a Stretchable Substrate

Abstract: A mechanically reconfigurable metasurface that can continuously tune the wavefront is demonstrated in the visible frequency range by changing the lattice constant of a complex Au nanorod array fabricated on a stretchable polydimethylsiloxane substrate. It is shown that the anomalous refraction angle of visible light at 632.8 nm interacting with the tunable metasurface can be adjusted from 11.4° to 14.9° by stretching the substrate by ∼30%. An ultrathin flat 1.7× zoom lens whose focal length can continuously be changed from 150 to 250 μm is realized, which also demonstrates the potential of utilizing metasurfaces for reconfigurable flat optics.

Zoom lens and imaging apparatus

Abstract: An object of the present invention is to provide a low-cost, miniature, wide-angle high-zoom-ratio zoom lens that has high imaging performance, and an imaging apparatus equipped with the zoom lens. To achieve the object, a zoom lens including a first lens group having positive refracting power, a second lens group having negative refracting power and a third lens group having positive refracting power in order from an object side in which a lens group P having positive refracting power is arranged closer to an image plane side than the third lens group.

zoom lens system

Abstract: A zoom lens system includes a negative first lens group and a positive second lens group. The negative first lens group includes a negative lens element and a positive lens element. The positive second lens group includes a positive lens element, a negative lens element, and a positive lens element. At least the object-side positive lens element and the negative lens element are cemented together. The zoom lens system of the present invention satisfies the following conditions: 1.5 1 wherein f2G: the focal length of the positive second lens group; mW: the lateral magnification of the positive second lens group at the short focal length extremity; and mT: the lateral magnification of the positive second lens group at the long focal length extremity; fT: the focal length of the entire zoom lens system at the long focal length extremity; and fW: the focal length of the entire zoom lens system at the short focal length extremity.