Showing papers on "Apochromat published in 2001"

Ophthalmic lenses for high order aberration correction and processes for production of the lenses

Abstract: The invention provides multifocal ophthalmic lenses that have zones of more than one optical power, or focal length. The lenses correct for high order optical aberrations in more than one field of gaze.

Symmetric anastigmatic endoscope relay system

Abstract: A symmetric relay system for endoscopes includes an optically-aligned pair of elongated concavo-convex rod-type lenses formed from crown glass, to the convex end surface of each of which a meniscus-shaped flint lens is cemented. The concave ends of the rod lenses are disposed to face the intermediate images of the relay system, and the convex ends to face the aperture of the relay system. A pair of achromatic lenses, each formed of a pair of lens elements x, y, are disposed adjacent and in optical alignment with the respective concave ends of the rod lenses between the concave rod ends and the intermediate images. Each achromatic lens fulfills the condition n x /n y =v x /v y . Apochromatic glass combinations may be used in the rod lenses to significantly reduce the secondary spectrum.

Liquid immersion system microscopic objective lens

Abstract: PROBLEM TO BE SOLVED: To realize an apochromat liquid immersion system microscopic objective lens which has a high numerical aperture exceeding NA 1.4 and is well corrected of spherical aberrations, chromatic aberrations and curvature of image by using a standard oil without using special oils. SOLUTION: This objective lens consists a first lens group consisting of a planaconvex cemented lens having a cementing surface of which the concave face is directed to an object side, a second lens group including at least one element of positive lenses, a third lens group including at least one three-element cemented lenses, a fourth lens group including a negative lens of which the strong concave face is directed to an image side and a fifth including lens group of a meniscus shape of which he concave face is directed to the object side. The objective lens described above is so constituted as to satisfy the following conditions (1) and (2): (1) 0.6<=|R12 /R13 |<=1.4 (2) 0.7<=|R12 /f|<=1.5.

Zoom lens and optical instrument using the same

Abstract: A negative-lead type zoom lens has a diffractive optical element and is led by a lens unit having a negative optical power. In this zoom lens, various kinds of aberration including chromatic aberration are excellently corrected by properly setting the lens configuration of each lens unit so as to achieve high optical performance over the entire range of a variable power while the entire lens system is miniaturized and designed to have a wide angle. The zoom lens according to the present invention is suitable for a zoom lens with a wide angle including a wide-angle region that is a focal length of substantially 28 mm on a 35 mm single lens reflex camera basis.

Objective lens device for correcting chromatic aberration and optical pickup employing the same

Abstract: An objective lens device and an optical pickup employing the objective lens device. The objective lens device is formed of three lenses including a lens having a negative power and formed of material having an Abbe number which is 45 or less in line d. At least one surface of surfaces of the three lenses is formed to be aspherical. Thus, in the objective lens device, a high numerical aperture of 0.70 or more is realized and chromatic aberration is corrected with respect to blue light enabling improved recording and/or reproduction using blue light.

Zoom lens aberration correction algorithm

Abstract: A procedure is described for the third order optical design of zoom objectives. Formulae derived from the stopshift equations are developed to enable computation of component spherical aberration and central coma targets necessary for seidel aberration stability through zoom and focus.

Objective lens for parallel stereomicroscope

Abstract: PROBLEM TO BE SOLVED: To provide an apochromatic level parallel stereomicroscopic objective lens of high magnifying power and high NA, capable of thoroughly removing chromatic aberration. SOLUTION: The lens is provided with a 1st lens group G1 whose refractive power is positive and which includes a biconvex cemented lens, and a 2nd lens group G2 including at least two cemented lens groups in order away from the object.

Hybrid lens with refraction- and diffraction-lens structure e.g. for optical memory disc device, has refraction lens designed such that the coma is largely corrected and changes in spherical

Abstract: Hybrid lens having a refractive lens and a diffraction lens structure designed such that a change in the spherical aberration caused by a change in the refractive index, is reduced.

Chromatic Properties of Si02-BaO-TiO2-K2O Series Radial Gradient-Index Material

Abstract: Chromatic properties of SiO2-BaO-TiO2-K2O series radial gradient-index material in the range of visible wavelengths are presented and the possibility of apochromatic microscope objectives is considered.

Apochromatic correction of hybrid lens

Abstract: In this paper, it has been shown an apochromatic triplet can be designed without employing special glasses. This possibility is offered when optical system is composed of two lenses, i.e., hybrid and glass ones. Such a system is proposed and its spherochromatic aberration is determined. Aberration characteristic of the system is compared with that of conventional glass apochromat.

Objective lens and optical head

Abstract: An objective lens comprising two or three lenses in which at least one of the lenses has a rotationally symmetric aspherical face and the aberration performance to two lights having different wavelengths lambda 1, lambda 2 ( lambda 1