Abstract: A fast photographic lens system comprises a first lens having a positive refractive power, a convex-shaped outer face and a flat inner face; a second lens having a positive refractive power, a convex-shaped outer face and a concave-shaped inner face; a third lens having a negative refractive power, a slightly convex-shaped outer face, and a concave-shaped inner face; a fourth lens having a negative refractive power and a concave-shaped inner face; a fifth lens, joined with the fourth lens, and having a positive refractive power, a relatively flat inner face and a convex-shaped outer face; a sixth lens having a positive refractive power, a slightly concave-shaped inner face and a convex-shaped outer face; and a seventh lens, having both convex-shaped inner and outer faces.

Abstract: An optical lens system includes a multi-element lens designed to maximize light collection efficiency and transmission but accepting a sufficiently high level of distortion to forego the system from imaging light patterns at each of a set of wavelengths at which the patterns are being emitted from a planar source simultaneously. The system also illustratively includes a cooled CCD camera with a dewar and filter assembly which is movable along the optic axis of the system to specified positions for selecting a particular wavelength at which an image is in focus so that the light pattern (image) at each different wavelength can be captured at a different time. A CCD camera is used to capture the image and the camera controller includes software to reduce the amount of distortion introduced by the lens.

Abstract: A double sided telecentic measurement objective for contactless length measurement in two-dimensional and three-dimensional space. The objective has an image-side optical system consisting of three elements equivalent to those of an object-side optical system but in the reverse order, including a cemented positively refracting lens element turned toward the object of image respectively, a collecting lens spaced by an air gap from the cemented lens, and a dispersive meniscus spaced by an air gap from the collecting lens. The widths of the air gaps between the collecting lenses and the meniscus are substantially greater than the widths of air gaps between the cemented lens elements and the collecting lenses.

Abstract: A photographic lens system comprises, in order from the object end, a positive power element having a concave image end surface, an element having a concave image end surface, a negative power element, a positive power element, a meniscus element of a positive power having a concave object end surface, and a doublet comprising a negative power element having a concave object end surface and a positive power element having a convex image end surface, and satisfies the following conditions:0.28<f/f4<2.55 (1)0<f/f5<1.80 (2)-1.15<f/f67<0.65 (3)-0.55<(R6-R7)/(R6+R7)<-0.17 (4)0.03<(R10-R11)/(R10+R11)<0.31 (5)-0.45<(R11-R14)/(R11+R14)<0.10 (6).

Abstract: A projection optical system for a liquid crystal projector having a plurality of lenses and projecting an image from liquid crystal display devices onto a screen including a front lens portion having a meniscus lens, a first concave lens, a convex lens and a second concave lens sequentially arranged from the furthermost of an image plane. A rear lens portion is also provided having two plano-convex lenses positioned between the front lens portion and image plane (display screen), with the flat surfaces thereof facing the image plane. The projection optical system for a liquid crystal projector having a compact size and capable of projecting focused images on the screen by adjusting the distance between the front and rear lens portions.

Abstract: A lens system includes a master lens system and a conversion lens system. The master lens system has a first lens, a second lens, a third lens, and a fourth lens, which are sequentially arranged from an object side of the lens system to an image side thereof, and has a first diaphragm which is arranged between the third lens and the fourth lens. The first lens is a positive meniscus lens having a convex surface toward the object side. The second lens is a negative lens. The third lens is a positive lens. The fourth lens is a negative meniscus lens having a concave surface toward the object side. The conversion lens system is arranged in such a manner that the conversion lens system can be freely inserted and removed between the third lens and the fourth lens of the master lens system.

Abstract: An objective lens is corrected for spherical aberration at both an operating wavelength and a measurement wavelength, such that the amount of spherical aberration to develop at the operating wavelength is substantially equal to the amount of spherical aberration to develop at a measuring wavelength. The method of lens performance measurement then uses a light source emitting at a wavelength different from the operating wavelength.

Abstract: A reading lens for a scanner to read an original in a reduced magnification, the lens comprising six lenses, i.e., from a first lens to a sixth lens in order on an optical axis. The first lens is a positive lens having a first lens-surface and a second lens-surface. The second lens is a negative lens disposed in contact with the first lens and has the second lens-surface in common with the first lens and a third lens-surface. The third lens is a meniscus lens and has a fourth lens-surface and a fifth lens-surface. The fourth lens is a meniscus lens and has a sixth lens-surface and a seventh lens-surface. The fifth lens is a negative lens and has a eighth lens-surface and a ninth lens-surface. The sixth lens is a positive lens disposed in contact with the fifth lens and has the ninth lens-surface in common with the fifth lens and a tenth lens-surface. At least one of the ten lens-surfaces is formed as an aspherical surface.

Abstract: An objective lens comprising, respectively from the object: a first element of a positive lens, at the object end thereof, having a convex surface; a second element of a positive meniscus lens, at the object end thereof, having a convex surface; a third element of a negative lens, at the image end thereof, having a concave surface; a fourth element of a single lens or a cemented lens, at the object end thereof, having a convex surface, wherein the cemented lens includes two or three lenses; a fifth element of a negative lens, at the object end thereof, having a concave surface; and a sixth element of a positive lens, at the object end thereof, having a convex surface. The objective lens satisfies the following three conditional equations, assuming that "f" designates the focal distance of the entire lens system:0.44f<R II<0.65f (1)0.63f<R IV<1.00f (2)0.55f<S III+D IV<0.

Abstract: An improved Gauss-type reading lens system having high lens performance in which there is only a small difference in performance in the meridional and sagittal directions and which can efficiently correct aberrations at various operating wavelengths to produce only limited chromatic aberrations. The system includes, in order from the object side, a positive meniscus first lens element having a convex surface directed toward the object, a positive meniscus second lens element having a convex surface directed toward the object, a negative meniscus third lens element having a convex surface directed toward the object, a negative meniscus fourth lens element having a concave surface directed toward the object, a positive meniscus fifth lens element having a concave surface directed toward the object and a biconvex sixth lens element. The second and third lens elements are cemented and the fourth and fifth lens elements are cemented. The reading lens system satisfies certain conditions.

Abstract: An objective of some 10 magnifications usable with microscopes, etc. which has an increased numerical aperture and working distance, including a first lens component that is a cemented lens consisting of negative and positive lens elements, a second lens component a third lens component, a fourth lens component consisting of a cemented lens and a fifth lens component having a positive refractive power, characterized by satisfying the following conditions:.nu..sub.I2 -.nu..sub.I1 >20 (1)n.sub.I1 -n.sub.I2 >0.2 (2)wherein:n.sub.I1 is the refractive index of d-line of the negative lens element of the first component,.nu..sub.I1 is the Abbe's number of said negative lens element of the first lens component,n.sub.I2 is the refractive index for d-line of the positive lens element of the first lens component, and.nu..sub.I2 is the Abbe's number of said positive lens element of the first lens component.

Abstract: An achromatic zoom beam expander of the Galilean type. The disclosed zoom beam expander has three components, each having a doublet that is individually color corrected such that the zoom beam expander may be used with a laser such as an argon ion laser which generates light energy at several different wavelengths.

Abstract: A projection lens enlarges and projects optical images in a matrix type light valve onto a screen. The projection lens includes a front lens group of the retrofocusing type; a rear lens with aspherical surfaces whose radii of curvature in the peripheral portion are shorter than that in the central portion; and a reflecting mirror which is positioned between the front lens group and the rear lens and diverts the optical axis. This projection lens enables the optical images in the light valve to be projected with a high contrast and a wide field angle. A projection system is provided which includes a light source; a light valve; a converging optical apparatus; a transmission type screen; diverting place mirrors; and a projection lens to enlarge and project the optical images in the light valve onto the screen. Since the projection lens has a wide field angle and has the reflecting mirror provided therein, the projection system can be very compact.

Abstract: A zoom lens for a variable magnification copying machine has a first lens composed of a concave lens; a second lens composed of a convex lens; a third lens composed of a meniscus concave lens and having a concave face on an object side; a diaphragm; a fourth lens composed of the same lens as the third lens and having a concave face on an image face side; a fifth lens composed of the same convex lens as the second lens; a sixth lens composed of the same concave lens as the first lens; the first to sixth group lenses being sequentially arranged from an object face toward the image face; the first to sixth lenses being symmetrically arranged around the diaphragm when the object is formed as an image on the image face at equal magnification; and a device for symmetrically moving at least the first and sixth lenses among the first to sixth lenses and the diaphragm and moving the entire lens system in the direction of an optical axis when the object is formed by changing the magnification as an image on the image f