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

Abstract: A zoom lens has three or more lens groups. A variable power lens group or at least one lens group located in a position nearer to an image than a variable power lens group serves as an image blur compensating group which is displaceable with respect the remaining lens groups. The magnification m.sub.C of the image blur compensating group satisfies a relation with respect to a composite focal length f.sub.1 of the lens groups nearer to an object than the image blur compensating group such thatm.sub.C =1/{1+(f1/A)}wherein A is an arbitrary constant.

Abstract: A wide angle zoom lens system having a high level of brightness includes a zooming subsystem comprising first and second movable lens units and a fixed third lens unit. The first lens unit has at least one aspherical lens surface. In the preferred embodiment, a diaphragm is disposed between the second and third lens units and is displaced independently of the second lens group when zooming.

Abstract: A family of achromatic lens triplets and an apochromatic lens triplet are described, each of which consists of a fluidal liquid lens element (viz., Cargille 550206 liquid) contained between a Schott BK 7 glass lens element and a Schott F2 glass lens element.

Abstract: A projection lens system for projecting a magnified image from an image source (3, 4, 5) on a projection screen (10) comprises from the image end successively a first, positive lens group (L.sub.1) and at least a second, negative lens group (L.sub.3) whose surface (S.sub.6) facing the image end is concave. The first lens group consists of a single lens element (L.sub.1) which in addition to a first refractive surface (S.sub.1) facing the image end and a second refractive surface (S.sub.2) facing the object end has a third radiation-reflecting surface (S.sub.3) which is located between the first and the second surface.

Abstract: The present invention pertains to a Fresnel lens type complex reflecting system in which a set of parabolic mirrors are utilized to function as a convex lens. This is accomplished through incident light rays impinging on concave surfaces of the parabolic mirrors. In this way, the focal point of the complex reflecting system will be on an opposite side of the complex reflecting system as the direction of incident light. Another feature of the present invention is an orientation of a set of parabolic mirrors which function to operate as a concave lens. This is accomplished through incident light rays impinging on convex surfaces of the parabolic mirrors.

Abstract: A stereoscopic graphics display system (10) includes a binocular viewing model generator (96) that automatically adapts a binocular viewing model to a selected stereoscopic image. An extrema accumulation unit (90) identifies extrema data corresponding to a region that bounds the selected image. The extrema data are delivered to the binocular viewing model generator, which designates a zero disparity location within the region and a disparity angle that is compatible with the dimensions of the selected image. The binocular viewing model generated in accordance with the selected image allow it to be rendered with improved three-dimensional qualities.

Abstract: A biconvex rod lens for the optics assembly of a medical or technical endoscope comprises of a light transmitting rod and a correcting lens cemented to one end of the rod. The rod is provided with at least one cylindrical collar which is of greater diameter than the adjacent lengths of the rod, for supporting the rod lens on the inner surface of an internal tube in the shaft of the optics assembly. In order to avoid shear forces arising in the cemented joint between the rod and the correcting lens when the shaft and thus the tube are bent when the endoscope is in use, the correcting lens and the rod have, in the region of the cemented joint, a smaller diameter than the cylindrical collar or collars. Fracture of the rod lens is there by avoided.

Abstract: In an objective lens assembly for an optical instrument comprising inner and outer tube members with outer and inner engaged helicoidal screws, respectively, the normal trapezoidal-section main ridge of the helicoidal screw of the outer tube member is modified to provide one or more wall surfaces that reflect stray light from the object side of the objective lens assembly to prevent such light from reaching the image side of the assembly. The wall surface or surfaces are provided by one or more sub-ridges or grooves at the top of the trapezoidal-section main ridge. Bottom portions between successive elements of the main ridge may be angulated to prevent stray light reflected therefrom from reaching the image end of the assembly.

Abstract: A projection lens for a projector according to the present invention comprises, in order from the screen side, the first lens unit including at least one positive lens and negative lens, the positive second lens including at least one negative lens and positive lens, and the negative third lens unit with a concave surface having a large curvature directed at the screen side, the first lens unit merely comprising spherical lens elements, at least one of the negative lenses in the first lens unit having a concave surface of larger curvature directed at an adjacent convex surface at the object side (CRT side), the second lens unit or the third lens unit having at least one or more aspherical surfaces. Thereby, an image quality of high definition as in a high quality television is realized without employing an aspherical surface is a portion where error in fabrication affects greatly aberrations due to the aperture, the affection tending to occur when an aspherical lens is used in the first lens unit.

Abstract: A copying lens system composed of a four-unit-four-element configuration including, in order from the object side, a first lens element of positive meniscus having a convex surface directed toward an object, a second lens element of negative meniscus having a convex surface directed toward the object, a third lens element of negative meniscus having a convex surface directed toward an image, and a fourth lens element of positive meniscus having a convex surface directed toward the image. In this configuration, the first lens element and the fourth lens element have the same geometric shape, and are disposed symmetrically with respect to a central diaphragm stop. The second and third lens elements also have the same geometric shape, and are also disposed symmetrically with respect to the central diaphragm stop. This provides an overall symmetrical configuration which can compensate for various aberrations.

Abstract: A compact and light-weight aspherical single lens with first and second surfaces that are aspherical surfaces of predetermined shapes. The distance from an arbitrary point on the aspherical surface to the tangential plane of the vertex of the aspherical surface is x; the distance from the arbitrary point to the optic axis in H; the reference radius of curvature of the vth surface is R.sub.v, the cone constant of the vth surface is K.sub.v and the aspherical coefficient of the vth surface is A.sub.vi (i=3,4 . . . ). The aspherical surface specifically satisfies the conditions (1), (2) and (3), as disclosed hereinafter, to create a simplified lens with high imaging performance.

Abstract: A lens or lens system for use in reading optical data has as one component a pickup lens having finite or infinite conjugates. The pickup lens is biaspheric where the surfaces may have spherical, paraboloidal or general conic base curves and higher order correction terms up to 40th order when required. Various methods of making such a lens of plastics material are also disclosed.

Abstract: A lens barrel of a zoom lens is comprised of a plurality of lens groups securely held by respective movable lens holders, a stationary cam ring having one or more stationary cam slots, a movable cam ring having one or more movable cam slots and rotatably supported about the stationary cam ring, and one or more pins extending through the stationary cam ring and the movable cam ring for connecting the first and second movable lens holders to move them together at the time of zooming.

Abstract: A compact zoom lens system comprising from the object side to the image side, a first lens unit of a negative refractive power having a cemented lens component consisting of a negative lens element and a positive lens element cemented with each other, said first lens unit being shiftable along an optical axis of the lens system in zooming operation, a second lens unit of a positive refractive power having two positive lens components, at least one of which consists of a positive lens element and a negative lens element cemented with each other, said second lens unit being shiftable along the optical axis of the lens system in the zooming operation and a third lens unit of a positive refractive power having from the object side, a front lens component of a negative refractive power and a rear lens component of a positive refractive power, said third lens being stationary along the optical axis of the lens system in the zooming operation, in order to realize a zooming ratio of about two or three, a very short o

Abstract: A zoom lens comprising: a first, when counted from an object side hereinafter, lens group having a positive refractive power; a second lens group having a positive refractive power; a third lens group having a positive refractive power; and a fourth lens group having a positive refractive power, whereby variation of magnification is performed by moving the second lens group and the fourth lens group, and focusing is performed by moving the fourth lens group, the lens group satisfying the following conditional expressions provided that a focal length of the fourth lens group is f4, a focal length of the entire lens system at a wide-angle end is f.omega., a zoom ratio is z, and an imaging magnification at a telephoto end of the second lens group is .beta.

Abstract: An optical system housed within a waterproof package includes, from front to rear, front lens and a rear group of lenses. For both of the front and rear surfaces of the front lens, proper numerical limits of the refractive power of the rear lens group are given to provide an amphibious camera which give a proper optical performance not only in the air but also under water without the necessity of focus adjustment.

Abstract: The articulated arm of a laser equipment comprises at least an articulation with a corresponding mirror in a fixed and non-adjustable position with respect to said articulation. At least one of the sections of the articulated arm converging into said articulation is engaged with the articulation in an angularly adjustable manner. In this way, with an angular adjustment of said arm section a perfect alignment of the laser beam in the tubular arm can be achieved.

Abstract: A zoom lens is disclosed, comprising a front lens group including a compensation lens sub-group arranged to move in a direction having a directional component transverse to the optical axis in order to stabilize the image, and a rear lens group positioned in the rear of the front lens group, the front and rear lens groups being moved along the optical axis when zooming is performed.

Abstract: An optical system comprising two plastic elements is suitable for use in very low cost, wideangle cameras having curved image surfaces. This system has low distortion across a curved field angle of 65 degrees or more.