Abstract: An eyepiece lens system using an aspherical lens can be formed at a low cost, having an eye relief equivalent to 80% or more of the focal length of the entire eyepiece lens system, with aberrations satisfactorily corrected up to the circumference of the field of view, as well as a telescope, a binocular and a microscope. The eyepiece lens system comprises a cemented lens and a positive lens, and at least one of the lens surfaces is formed aspherical. The aspherical surface is a hybrid type spherical surface formed by applying a synthetic resin layer on a basic spherical surface made of glass. There are also provided a telescope, a binocular and a microscope employing such eyepiece lens system.

Abstract: A negative ocular having a positive eye-side lens element positioned on the side of the user's eye and a positive field lens element positioned on the side of the object whereby an intermediate image formed by an objective lens system is formed between the eye-side lens element and the field lens element, and whereby the eyepiece lens system satisfies the following conditions: 0.8<L(1+S)/{f1(P+S)}<1.05   (1) 0.5<S(1—1/P)/(1+S)   (2) wherein S=&ngr;1/&ngr;2; P=f2/f1; f1 designates the focal length of the eye-side lens element; f2 designates the focal length of the field lens element; &ngr;1 designates the Abbe number of the eye-side lens element; &ngr;2 designates the Abbe number of the field lens element; and L designates the distance between the principal points of the field lens element and the eye-side lens element.

Abstract: There is provided an eyepiece lens system for viewing an image formed by an objective lens system. The eyepiece lens system includes a first refraction lens having a positive power, a second refraction lens having a positive power and at least one diffraction lens having a phase grating structure. The first and second lenses are arranged on an eye side with respect to a plane on which the image is formed.

Abstract: A video interface linking a base station with a remote display, e.g., a head-mounted display, converts input video signals from NTSC or PAL formats into modulated video signals containing repetitive sequences of frame times with embedded audio and control signals. Each frame time includes equal consecutive color field times. Frame rates are converted by inserting selected repeating color frames into the datastream. Bursts of image information occupy a portion of each field time. During each data burst, the display is loaded with pixel luminance data. Between bursts, the display is illuminated by a color LED. Two video displays can be driven alternately, i.e., the first display loads while the second is illuminated. The modulated video signal can travel through the atmosphere on an infrared (IR) beam with a wavelength between 700 nm and 1100 nm. In one embodiment, the beam is scattered from a diffuse reflecting surface. Alternatively, the beam is shaped by a shaping lens.

Abstract: An eyepiece system comprising, in order from the object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, and configured to locate an intermediate image formed by an objective lens system between the first lens unit and the second lens unit: the first lens unit being a negative lens unit having an object side surface which is convex toward the object side. This eyepiece system has a wide visual field and a long eye relief, and corrects aberrations favorably even at marginal portions of the visual field.

Abstract: An eyepiece system comprising a single radial type gradient index lens which has a refractive index varying dependently on distances from an optical axis in a radial direction and a negative power. This eyepiece system is composed of a small number of lenses, and has chromatic aberration, curvature of field, spherical aberration, etc. which are corrected favorably.

Abstract: A viewfinder optical system has a relay lens system. The relay lens system focuses a primary image to form a secondary image. The relay lens is provided at an optical conjugate point with respect to a pupil. A surface of the relay lens system has an optical power of diffraction. The surface is positioned between the primary image and the optical conjugate point. The surface also has optical power of refraction.

Abstract: An aberration correction system having a first lens disposed at an object side; and a second lens disposed at an image side, wherein the first and second lenses have different dispersions (Abbe numbers) with respect to each other, the surface of the object side of the first lens and the surface of the image side of the second lens which is adjacent to the image have substantially common center of curvature and the first and second lenses rotate around the center of curvature.

Abstract: A goggle is provided with double unitary lenses, separated by an insulating space to reduce fogging. At least one of the lenses is tapered to reduce prismatic distortion through the lens in an as-worn orientation. In an exemplary goggle, the tapering of one lens compensates for prismatic distortion and/or astigmatism introduced by the other of the lenses. The lenses are mounted in a goggle frame in a predetermined orientation with respect to a wearer's normal lines of sight. In one embodiment, the optical centerline or axis of the double lens system is aligned to be parallel with the wearer's normal lines of sight in the as-worn orientation. Method of manufacturing such lenses is also provided. The illustrated goggle defines an enclosed space between the inner lens and the wearer's face when worn, but includes ventilation to the enclosed space to allow moisture to escape.

Abstract: A drive device for driving an optical element suitable to be attached to a camera shake correction device. The drive device employs items molded from a synthetic resin in which the elastic deformation of the synthetic resin allows the oscillation of a piezoelectric element to be adequately converted to drive power. The drive device includes an electromechanical conversion element, a baseplate equipped with a securing area secured to one end of the electromechanical conversion element, and a drive member that is securely linked to the other end of the electromechanical conversion element and displaced together with the electromechanical conversion element. The device further includes a transport member constructed from a rigid synthetic resin material with a Rockwell hardness of about 120 or more and which is frictionally linked to the drive member.

Abstract: An eyepiece lens comprising a single gradient-index lens having a positive refracting power, or comprising a radial gradient-index lens having a positive refracting power, and a field lens, wherein the following Eqs. are satisfied:1<.PHI..sub.m /.PHI.<1.5 (1).vertline..PHI..sub.S1 /<-.PHI..sub.S2 (2)-0.01<1/V.sub.1 <0.025 (3)where .PHI. is the refracting power of the radial gradient-index lens, .PHI..sub.m is the refracting power of a medium of the radial gradient-index lens, .PHI..sub.S1 is the refractive power of a surface located on the eye side of the radial gradient-index lens, .PHI..sub.S2 is the refracting power of a surface located on the object side of the radial gradient-index lens, and V.sub.1 is a coefficient of color dispersion of the medium of the radial gradient-index lens.

Abstract: An optical system for a view finder reduced in the overall length without aggravation of the optical performance has a negative power object lens and a positive power eyepiece lens each of which has an asphrical surface at at least one side respectively. The negative power object lens having a concave object side lens surface is comprised of a rectangular-shaped solid lens base with its four corners cut away along periphery of the concave lens surface.

Abstract: An ocular optical system for a viewfinder in a camera for observing object image which is formed on focusing glass or its vicinity via eye point. The ocular optical system includes, in order from the focusing glass side, a negative meniscus lens, which has its convex surface facing the focusing glass side, and a positive lens. Visibility compensation is performed by moving the positive lens along the optical axis without moving the negative meniscus lens.

Abstract: An eyepiece system comprising, in order from the object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, and configured to locate an intermediate image formed by an objective lens system between the first lens unit and the second lens unit: the first lens unit being a negative lens unit having an object side surface which is convex toward the object side. This eyepiece system has a wide visual field and a long eye relief, and corrects aberrations favorably even at marginal portions of the visual field.

Abstract: A finder system for a single lens reflex camera includes a focusing screen having a split prism, a penta roof mirror and an eyepiece lens system. The penta roof mirror has a hollow housing made of plastic material in the shape of a pentagonal prism whose three surfaces are coated inside to reflect light. The eyepiece lens system includes two plastic lenses, each of which has a different dispersion.

Abstract: According to the present invention the magnifier lens comprises two lens elements. More specifically, from a front, eye side to a rear, object side there is a front, positive lens element, and a rear, meniscus lens element. The front, positive power lens element has at least one aspheric surface and an Abbe V-number V.sub.1. The rear, meniscus lens element has an Abbe V-number V.sub.2. The front and the rear lens elements, in combination, contain at least one diffractive surface. The rear, meniscus lens element has front and rear refractive surfaces, both of which are concave toward the object side. The rear refractive surface is positionable within 5 mm of an associated object to be viewed from the eye side. This rear surface is an aspheric surface of negative refractive power. The Abbe V-numbers satisfy the following inequalities 50.4<V.sub.1 <65, 25.4<V.sub.2 <40, and V.sub.1 -V.sub.2 >25.

Abstract: A high-performance eyepiece is provided having a high-power magnification finder and a large pupil diameter even if it is used for a camera finder using a pentagonal mirror. The eyepiece includes, in order from the eyepoint end, a negative meniscus lens and a bifocal convex lens, which fulfills the following conditions:0.88<d1/d3<2.7and0.15<r1/f1<0.26where:d1 is the center thickness of the negative meniscus lens;d3 is the center thickness of the biconvex lens;r1 is the radius of curvature of the surface at the eyepoint end of the negative meniscus lens; andf1 is the focal length of the negative meniscus lens.

Abstract: A compact eyepiece is disclosed for use with an objective lens in a microscope, binocular, telescope, etc., that favorably corrects optical aberrations over a sufficiently wide apparent field of view and that offers an eye relief that is larger than the focal length of the eyepiece. The eyepiece comprises, in order from the objective side, a negative first lens group G1 and a positive second lens group G2. The second lens group has an objective-side focal plane situated between the first lens group G1 and the second lens group G2. The second lens group G2 comprises, in order from the objective side, a first lens subgroup G21 having positive refractive power and comprising a positive lens element G21A and a positive cemented lens G21B, and a second lens subgroup G22 having positive refractive power and comprising a positive lens element. The eyepiece satisfies certain quantitative conditions.

Abstract: An eyepiece system includes a single positive lens and a cemented lens assembly having a positive biconvex lens and a negative lens cemented thereto, in this order from the object side. The eyepiece satisfies the relationships defined by d<0.3f, and f.sub.1 >1.5f, wherein "d" represents a distance between the single positive lens and the cemented lens assembly, "f" a focal length of the whole lens system, and "f.sub.1 " a focal length of the single positive lens.

Abstract: An eyepiece system for use with binoculars, etc. which comprises, in order from a side of an observer's eye, a first convex lens element having a strongly convex surface on a side of an objective lens, and a cemented doublet lens component which consists of a second biconvex lens element and a third negative or negative meniscus lens element. This eyepiece system is configured to have a wide apparent field angle and favorably corrected aberrations by selecting an adequate value for a distance as measured from a front focal point of the eyepiece system to a vertex on a surface of the first lens element which is located on the side of the observer's eye.

Abstract: An eyepiece lens is disclosed that corrects aberrations over a wide apparent field of view, and has a short overall length and sufficiently long eye relief (typically at least 150% of overall focal length F). The eyepiece lens comprises, in order from the objective lens side, first and second lens groups having negative and positive refractive power, respectively, with a field stop situated therebetween. The first lens group comprises a cemented negative lens including two lens elements cemented together. The second lens group comprises, in order from the objective lens side, a positive meniscus lens element having a concave surface oriented objectivewise; a cemented lens comprising two lens elements cemented together and in which the most objectivewise lens surface is a concave surface oriented objectivewise; and a lens subgroup having positive refractive power and comprising a positive meniscus lens element having a concave surface oriented eyewise. The eyepiece lens satisfies at least the conditions: -4.5.

Abstract: A real image type zoom finder optical system is constructed by an objective optical system, an erect orthoscopic optical system and an eyepiece optical system sequentially arranged from an object side. The objective optical system is composed of first to fourth lens groups each constructed by a single lens. The erect orthoscopic image optical system is composed of two erect prisms. The eyepiece optical system is composed of one lens group. A front face of the second lens group is constructed by an aspherical surface such that the first, second, third and fourth lens groups respectively have positive, negative, positive and positive refracting powers. A real image formed by the objective optical system is focused and formed within the erect orthoscopic image optical system. A zooming operation is performed by moving the second lens group from the object side to an eyepiece side on an optical axis of the finder optical system.

Abstract: An eyepiece lens system comprising a first positive lens component and a second positive lens component: the first lens component being composed of a single positive lens element, and the second lens component being composed of a single cemented doublet consisting of a positive lens element and a negative lens element. This eyepiece lens system has distortion which is corrected favorably by selecting an adequate refractive power for a cemented surface of the cemented doublet and is configured so as to have a sufficiently long eyepoint distance.

Abstract: An optical magnifier, preferably having only two elements and including a rear negative surface associated with an object to be viewed, which is aspheric. The aspheric surface follows a formula having a sag which is positive to help effect correction for field curvature, astigmatism and distortion. Preferably the lens has at least one other aspheric surface and a diffractive surface. The diffractive surface is preferably on a curved surface to assist in improving the quality of the magnifier with a limited number of elements.

Abstract: An eyepiece lens of the present invention and is arranged in a real image mode finder optical system consists essentially of a single positive meniscus lens convex on the object side having an object side surface and a pupil side surface, each of which is aspherical. This invention provides a compact eyepiece lens having a long optical path length from an image plane to the eyepiece lens, a large diameter of the exit pupil and a short focal length.

Abstract: An eyepiece having an apparent field of view of 40.degree. or greater which is provided, in succession from the eye point side, with a first lens unit G1 having positive refractive power as a whole, and a second lens unit G2 having negative refractive power as a whole and having a cemented negative lens disposed with a virtual image formed by the eyepiece interposed between itself and the first lens unit G1, satisfies the following conditions:1.0<f1/f<2.0-5.0<f2/f<-2.51.5<D/f<3.0,where f1 is the focal length of the first lens unit G1, f2 is the focal length of the second lens unit G2, D is the principal plane distance between the first lens unit G1 and the second lens unit G2, and f is the focal length of the entire lens system.

Abstract: An ocular lens includes, sequentially from an object side, a first lens unit G1 exhibiting a negative refracting power on the whole and a second lens unit G2 exhibiting a positive refracting power on the whole. An object-side focal surface of the second lens unit G2 is positioned between the first and second lens units G1, G2. At least one lens surface of the first lens unit G1 is formed in an aspherical shape.

Abstract: A telescope includes a master telescope whose aberration has been independently corrected and which has an objective lens and an ocular lens. A rear conversion lens is provided on the image side of the objective lens of the master telescope and is made of a single lens having a concave surface that faces an object side. The rear conversion lens meets the requirements defined by the following relationships: f.sub.o '/f.sub.o >1 and 0.5<(dx.sub.2 /dh.sub.2)/(dx.sub.1 /dh.sub.1)<1.3, wherein "f.sub.o " represents the focal length of the objective lens of the master telescope; "f.sub.o '" represents the resultant focal length of the objective lens of the master telescope and the rear conversion lens; "dx.sub.1 /dh.sub.1 " represents an inclination of an incident surface of the rear conversion lens at an incident point thereof, upon which light is incident at a height h.sub.1 ; "dx.sub.2 /dh.sub.

Abstract: An Albada type inverted Galilean finder for a camera has an objective lens of negative power having a concave surface on a pupil side opposite an object side which is provided thereon with a half mirror coating and an eyepiece having a convex surface on the pupil side and a surface on the object side which is provided thereon with a framing marking defining an area for framing.

Abstract: An eyepiece capable of compensating, various aberrations despite its simple construction including a relatively small number of lenses. The eyepiece includes, in the order from an eyepoint side, a first lens group of a positive refractive power composed of a single positive lens and a second lens group of a positive refractive power composed of a cemented lens of a positive lens and a negative lens, and the positive lens of the first lens group has at least one of its lens surfaces formed into an aspherical surface shape. The radius of curvature at the peripheral portion of the aspherical surface is greater than the radius of curvature at the apex portion of the aspherical surface.

Abstract: A wide field eyepiece lens system composed, in order from a side of an objective lens system, of a first lens unit which is composed of a plurality of lens elements and has a diverging function, and a second lens unit which is composed of a plurality of lens elements and has a converging function. The eyepiece lens system has an apparent field angle of 75.degree. to 80.degree., an eye relief of 0.95 f or longer and aberrations favorably corrected over an entire range of a visual field thereof including marginal portions, and is configured so as to satisfy the following conditions (1) and (2):-8.0<f.sub.1 /f<-4.8 (1)1.8<D/f<2.

Abstract: A real image type viewfinder is provided with, in the following order from the object side: an objective lens group, a condenser lens group which transmits the image of the object formed by the objective lens group towards an eyepiece lens group, an image erecting optical system that erects an inverted image, and, the eyepiece lens group. The eyepiece lens group consists of a negative lens and a positive double-convex lens, in this order from the eye side, and satisfies the following three relationships:-0.5<f.sub.E /f.sub.E1 <0 (1)-1.5<f.sub.E /r.sub.E1 <1.0 (2)0.03<d.sub.E1-2 /f.sub.E <0.1 (3)wherein f.sub.E designates the overall focal length of the eyepiece lens group; f.sub.E1 designates the focal length of the negative lens of the eyepiece lens group; r.sub.E1 designates the radius of the eye-side surface curvature of the negative lens of the eyepiece lens group; and d.sub.

Abstract: A re-imaging objective optical system provides superior optical performance while having a short overall length and a relatively simple composition. The system has, in order from the object side of the optical system, a front lens group (G1) composed of a first lens group having a positive lens component (L1), a second lens group having a biconcave negative lens component (L2) and a third lens group having a positive lens component (L3); and a back lens group G2 composed of a cemented double lens element with components (L4 and L5) and a positive lens component (L6). The spatial or primary image I.sub.1 from the objective optical system is formed on the optical path between the first lens group and the second lens group.

Abstract: A real image type of variable power view finder is disclosed which has an objective lens system, an image erecting optical system, and an eyepiece lens system, located in this order as viewed from an object to be photographed. The objective lens system includes negative and positive lens groups located in this order from the object side, so as to vary the distance therebetween, to change the magnification. The negative lens group of the objective lens system has at least two negative lenses.

Abstract: This invention provides for a magnification system (10) and a method of construction. The magnification system (10) includes at least a first lens (3) and a second lens (5) lying on a common central lens axis line with an object (1) to be magnified being placed on one side of both of the first lens (3) and the second lens (5). The first lens (3) is constructed in a manner to have a first lens focal length greater than the first lens object distance for forming a first lens virtual image (4). The second lens (5) has a second lens focal length which is greater than the focal length of the first lens (3) to form a second lens virtual image (7) having a greater magnitude than the first lens virtual image formed. Through a recursive image nesting method, additional lens groupings may be added to a basic lens set to increase the magnification while minimizing optical distortions of a previous lens grouping.

Abstract: The invention is directed to a color corrected ocular having a very simple configuration and excellent correction characteristics. The ocular includes a single lens at the eye end with the single lens having an aspherical surface r.sub.2 and a two-element composite lens (2, 3). The surface r.sub.3 of the composite lens adjacent to the aspherical surface r.sub.2 is a planar surface. In another embodiment, the composite lens includes a planar-convex lens 2 and a planar-concave lens 3 which are cemented to each other at respective convex and concave surfaces. The spacing d.sub.1 between the single lens 1 and the exit pupil 4 is sufficiently large so that the ocular is also suitable for a wearer of spectacles.

Abstract: A real image type of variable power view finder is disclosed which has an objective lens system, an image erecting optical system, and an eyepiece lens system, located in this order as viewed from an object to be photographed. The objective lens system includes negative and positive lens groups located in this order from the object side, so as to vary the distance therebetween, to change the magnification. The negative lens group of the objective lens system has at least two negative lenses.

Abstract: In an ocular lens system for use with a penta-mirror, an ocular lens includes a positive meniscus lens whose concave surface is directed to the pupil side and whose convex surface is directed to the object. The concave and convex surfaces of the positive meniscus lens are aspherical. The two surface are shifted to the pupil side from reference spherical surfaces defined by paraxial radii of curvature.

Abstract: An afocal zooming optical system includes, in order from the object side, an objective optical unit comprising a positive first lens group, an erecting prism component and a negative second lens group, and an eyepiece optical unit comprising a three-element positive third lens group and a single-element positive fourth lens group, which system performs zooming by moving the second and third lens groups in different directions along the optical axis and satisfies certain conditions.

Abstract: An ocular system is disclosed which is composed of at least three lens elements for constituting, in order from the eye side, at least first and second lens units. At least one of the lens elements is made of resin. Two of the lens elements are substantially cemented together. In addition, an aspherical plastic lens is effectively used in the system.

Abstract: An optical system for use in conjunction with a camera viewfinder having a penta-mirror comprises a positive first lens element and a negative second lens element satisfying predetermined conditions.

Abstract: An optical recording system including a read/write optical assembly including an objective lens for reading or writing from an optical medium including a solid immersion lens disposed between the objective lens and having a surface closely spaced from the recording medium.

Abstract: An eyepiece system which can be used in the eyepiece portion of an endoscope. The eyepiece system comprises, in order from an eye point, a first positive lens having two convex surfaces, a second negative lens having a concave surface facing to the eye point side, and a third positive lens having a convex surface facing to the eye point side. Due to such construction, the eyepiece system can be compact and light in weight, and it also can provide a high magnification. Further, the eyepiece system has a sufficient eye point distance. Accordingly, the eyepiece system is an ideal eyepiece system for an endoscope.