Abstract: The correcting lens comprises a plurality of regions which are formed at at least one portion of the effective surfaces on both sides of the lens by means of a plurality of border lines which are discontinuous in only one direction. The regions on one side are inclined in a direction different from that of the regions on the opposite side of the lens.

Abstract: The correcting lens comprises a plurality of regions which are formed at at least one portions of the effective surfaces on both sides of the lens by means of a plurality of border lines which are discontinuous in only one direction. The regions on one side are inclined in a direction different from that of the regions on the opposite side of the lens.

Abstract: A basic lens for a pancratic camera lens system having an afocal screen of variable enlargement in which the screen includes a primary, positive front component, second and third negative components, the total focal length of the second negative component being displaceable of the optical axis and the minimum focal length of the second negative element and the image field diagonal 2.sub.y having a relationship (f.sub.Gmin - f.sub.II)<6y, and a fourth positive component, the basic lens being constructed in the form of an assembly of six lenses including, in succession beginning with the lens facing the object to be photographed, a first biconvex lens, a second biconvex lens, a first biconcave lens cemented to the second biconvex lens, a second biconcave lens, a third biconvex lens and a positive meniscus, all arranged in aligned relationship in the direction of light incidence.

Abstract: A tracking lens system for solar collectors or skylights comprises a first array of condensing lenses, a movable array of diverging lenses, and a second array of condensing lenses. By moving the array of diverging lenses, sunlight incident from any small angle can be tracked. The light leaving the tracking lens system can be parallel rays coaxial with the lens system, or can be focused upon a collecting means.

Abstract: A retrofocus wide angle objective lens system of seven air-spaced lenses, the first and second lenses, counting in the order of the entrant light beam, being negative meniscus lenses of forward convexity, the third lens being a positive lens, the fourth lens being a bi-convex lens, the fifth lens being a bi-concave lens, and the sixth and seventh lenses being positive lenses. The third and fourth lenses are separated by a large axial air space, and the third lens has a larger diameter than the fourth lens.

Abstract: An objective for video disks comprising five lens components of single lenses for which the numerical aperture on the recording surface side is large, working distance is large and aberrations especially spherical aberration and coma are corrected favourably. Besides, said objective for video disks is arranged so that it can be used also for rays from infinite distance by varying an airspace between a second and third lens components.

Abstract: A circular array of twelve light sources transmit light to an eye. A spherical shape of the cornea of the eye is indicated when light reflected therefrom appears to be transmitted from twelve virtual light sources disposed along a circular path within the eye. Correspondingly, an aspherical shape of the cornea is indicated when the virtual sources appear to be disposed along an acircular path within the eye. The array may be disposed within a light reflecting groove which collects ambient light which is transmitted to the eye. A reflection of the collected light appears to be a ring of light which connects the virtual sources.

Abstract: A two-element objective having a numerical aperture of 0.10 in combination with a telescope objective as described in U.S. Pat. No. 3,355,234 and a typical 10.times. eyepiece has a magnification of 4.times. and a substantially flat 24mm image field.

Abstract: A large-aperture enlarging lens system which comprises a first positive meniscus lens component, a second positive meniscus lens component, a third lens component consisting of two lens elements, a fourth lens component consisting of two lens elements and a fifth positive lens component, either one of said third and fourth lens components arranged on both sides of a stop having a convex lens on the side of said stop, and wherein aberrations are favorably corrected.

Abstract: A Cassegrain telescope with spherical primary and secondary mirrors and a corrector plate located between the focal point and the center of the radius of curvature of the primary mirror. The secondary mirror is located between the focal point and the vertex of the primary mirror and the image surface is beyond or behind the vertex of the primary mirror.

Abstract: From an object side, there are a fixed lens, a first movable lens, a second movable lens, and a fixed lens being positioned in that order, wherein the first movble lens is coupled with a first position detecting means and the second movable lens is coupled with a second position detecting means, and at the same time it is coupled with a lens shifting means which is controlled by the above mentioned two detecting means. For photographing which involves zooming, first the second movable lens is shifted for focusing. Next, as the first movable lens is shifted, the amount of shifting is detected by the first detecting means and then the second movable lens is shifted based on the detected value of the same. The amount of shifting of said second movable lens is determined by a functional equation which has been set as the optical system is designed, while the position adjustment of the second movable lens is controlled by the lens shifting means and the second detecting means.

Abstract: A detector used in apparatus for measuring variations in the composition of a liquid includes a cell utilizing the Christiansen effect on light transmitted by the liquid flowing through the cell filled with particulate matter. The liquid and the particulate matter have indices of refraction that are substantially equal to one another at a specific wavelength. Variations of the transmitted light can determine changes of the refractive index of the liquid.Differences in the intensity of light transmitted through a sample cell and a reference device can be determined.

Abstract: A retrofocus-type objective for endoscopes comprising a front diverging lens group and rear converging lens group and arranged to be focused by keeping the front diverging lens group fixed and moving the rear converging lens group toward the front diverging lens group.

Abstract: An optical apparatus is disclosed which includes at least two optical systems for reproducing a plurality of data images on a common photographic plane. The systems are arranged to allow any desired orientation of the data images on the plane.

Abstract: A telephoto objective lens comprising a normally stationary front lens group having a positive power and a rear lens group having a negative power axially movable for focusing, the front lens group including at least two positive members and at least one negative member, and the rear lens group including at least one positive member and at least one negative member. The rear lens group has a negative meniscus configuration as a whole with the first refracting surface counting from the front being convex to the front and with the rearmost surface being concave to the rear. As the objective lens is focused from the position for an object at infinity to the position for a close object, only the rear lens group is moved toward the image plane.

Abstract: A reflection type image forming optical system having a large angle of view comprises a convex mirror for reflecting incident light and a concave mirror. The concave mirror is disposed with the reflecting surface thereof facing the reflecting surface of the convex mirror so that light reflected by the convex mirror at a large angle with respect to the normal thereof enters the concave mirror at a large angle and that light reflected by the convex mirror at a small angle with respect to the normal thereof enters the concave mirror at a small angle. The concave mirror is arranged so that the distance between the center of curvature of the convex mirror and that of the concave mirror is greater than half the radius of curvature of the concave mirror.

Abstract: A correcting lens for use in the formation of a color picture tube screen has a first effective surface comprised of a plurality of elements separated by boundaries of discontinuity. Each of the elements in the first effective surface is separately contoured to reduce misregister in the tube. The second effective surface, opposite the first, is contoured to additionally reduce misregister in the tube.

Abstract: An apparatus for continuously measuring the density of a liquid within prespecified limits, utilizing the law of refraction, particularly an apparatus for measuring the acid density of a motor vehicle storage battery for the purpose of determining its state of charge. The apparatus has an optical system with a photosensitive element and a light transmissive body with a measuring surface which is in contact with the liquid, and with a light source which illuminates the measuring surface.The light source has an illuminated surface with a non-directional transmission.The illuminated surface facing the measuring surface is spaced therefrom.The illuminating surface together with said measuring surface define an open container filled with the said liquid. A frosted glass disc illuminated by a lamp forms the illuminated surface.The optical system contains a convergent lens whose main plane, together with the measuring surface encloses a precisely defined acute angle.

Abstract: A high magnification microscope objective having a very large numerical aperture which comprises a first positive lens component, a second positive lens component, a third cemented lens component having positive refractive power, a fourth positive lens component and a fifth cemented lens component, and wherein chromatic aberration, curvature of field, etc. are favorably corrected.

Abstract: A compact retrofocus-type wide-angle objective for endoscopes comprising a front diverging lens group comprising a lens having negative power and a rear converging lens group comprising a positive lens on which absolute value of radius of curvature on the object side surface is larger than that on the image side surface and a cemented positive doublet lens whose cemented surface has negative refractive power.