Abstract: A zoom lens is comprised of a fixed barrel, an intermediate barrel coupled to the fixed barrel through helicoid screws, a movable barrel coupled to the intermediate barrel through helicoid screws, a front lens group fixedly held in the movable barrel, and a rear lens group. The position of the front lens group in the optical axis direction is always determined by the axial movement of the intermediate barrel relative to the fixed barrel and the axial movement of the movable barrel relative to the intermediate barrel. The axial position of the rear lens group is determined by the axial movement of the intermediate barrel relative to the fixed barrel and a cam surface formed in an inner periphery of the intermediate barrel. As the axial position of the cam surface within the intermediate barrel changes with the rotational position of the intermediate barrel, the rear lens group moves in the axial direction relative to the intermediate barrel during zooming.

Abstract: A catadioptric optical system includes a first imaging optical system forming an intermediate image of a pattern provided on a first surface with a reduced magnification, including a first lens group with a positive refracting power and a second lens group which includes a concave mirror having a negative lens component. The system also includes a second image optical system forming an image of the intermediate image upon a second surface, a combined magnification of the first and second imaging optical systems being a reduction magnification. The system further includes a deflecting member disposed in an optical path from the first imaging system to the second imaging system so as to guide light from the first imaging system to the second imaging system.

Abstract: To attain a compact wide-angle 2-unit zoom lens having a variable magnification range of 2.6 to 2.9 or thereabout which is well corrected for high optical performance throughout the entire variable magnification range with the total length shortened, the zoom lens comprises, in order from the object side, a first lens unit of positive refractive power and a second lens unit of negative refractive power, the separation between both the first and second lens units being varied to vary magnification, wherein an aspheric surface layer is formed on a lens surface of the object side among the lenses made of glass in the second lens unit by coating that lens surface with transparent resin and then setting the transparent resin.

Abstract: A polymer composition is provided for use as a liquid lens element in a compound lens designed to reduce chromatic aberration. The polymer composition (i) has an abnormal optical dispersion and (ii) is more easily fabricated into the compound lens than a conventional optical liquid. The composition contains an abnormal optical liquid characterized by an abnormal optical dispersion and a polymer component. The polymer is soluble in the optical liquid and is present in an amount effective to impart a viscosity that is at least an order of magnitude greater than that of the liquid alone at a selected temperature.

Abstract: A zoom lens barrel and a method of adjusting the flange back focal distance of the zoom lens barrel is disclosed. The zoom lens barrel includes mounting members for mounting the zoom lens barrel on a camera body; a zoom ring that rotates for zooming relative to the mounting members; an adjustment member that may rotate with or relative to the zoom ring; and a cam ring. The cam ring is screwed to the adjustment member and moves in the optical axis direction due to the rotation of the adjustment member when the adjustment member rotates relative to the zoom ring, and when the adjustment member and the zoom ring both rotate, the zoom ring and the adjustment member rotate together. Lens units move in the optical axis direction due to the rotation of the cam ring.

Abstract: A zoom lens includes at least two lens groups, i.e., a first lens group and a second lens group. The second lens group includes a first sub-group near to the first lens group and a second sub-group far from the first lens group, and the first lens group and the first sub-group in the second lens group together form a substantially afocal system in at least a portion of a zooming range. In the zoom lens, focusing is effected by the first sub-group in the second lens group being moved along the optical axis. Considering a case where this zoom lens is applied for auto focusing, it is preferable that the first lens group be disposed on that side in the lens group which is most adjacent to the object side.

Abstract: With a stop disposed at the center, a lens system are composed of four sheets of positive, negative, negative, and positive lenses. At the time of variable magnification, the whole lens system is moved while distances between the lenses are changed, whereby a low cost and a compact size are attained in a zoom lens system for copying. This lens system is constituted by four sheets of positive, negative, negative, and positive lenses (L.sub.1 to L.sub.4) which are disposed in pairs laterally symmetrical to each other with respect to the stop. At the time of reducing or enlarging, the distance between the first lens (L.sub.1) and second lens (L.sub.2), the distance between the third lens (L.sub.3) and fourth lens (L.sub.4), and the distance between the second lens (L.sub.2) and third lens (L.sub.

Abstract: The present invention relates to an anamorphic lens for a CCD camera apparatus used for inspecting a semiconductor chip during the manufacturing process. The reduced image of the semiconductor chip being inspected is formed at a magnification of 0.25 times in the horizontal direction and a magnification ratio of 1:1 in the vertical direction. The anamorphic lens system for the CCD camera apparatus includes two spherical lens sets each having five lenses, and an afocal cylindrical lens system through which the image is formed in different ratios between its length and width. The spherical lens sets are positioned face-to-face on the same axis line. The afocal lens system includes an indefinite distance in its focus point, and the different magnification between length and width is positioned in a space between the two spherical lens sets. As a result, the image of the semiconductor chip being inspected is formed on a general CCD element 6.6 mm.times.8.8 mm in size after it is reduced by 0.25 times.

Abstract: A zoom lens is composed of a first lens group of a negative refractive power, a second lens group of a positive refractive power and a third lens group of a positive refractive power, in which, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases, the distance between the second and third lens groups varies, the distance between the third and fourth lens groups increases, and the distance between the fourth and fifth lens groups decreases.

Abstract: This invention relates to a catadioptric optical system in which, a large numerical aperture is attained on the image side and, while securing a sufficient working distance, the size of the beam splitter is reduced, thereby attaining a resolution of a quarter micron unit, and an exposure apparatus using the same. In order to form a reduced image of a pattern of a first surface on a second surface, this catadioptric optical system comprises, at least, a first lens group, a beam splitter, a concave mirror having an enlarging magnification, and a second lens group. These constitutional elements of the catadioptric optical system are disposed such that light from the first surface passes through the first lens group, the beam splitter, the concave mirror, the beam splitter, and the second lens group in this order.

Abstract: In a negative first lens group composed of four sheets of lenses and a positive second lens group composed of four sheets of lenses, the lens in each lens group placed closest to the enlargement side is formed as a plastic lens having an aspheric surface, while predetermined conditional expressions are satisfied, whereby various kinds of aberration are made favorable and influence of changes in the plastic lens upon temperature is suppressed. A first lens group comprising a negative first lens (L1) made of a plastic lens having an aspheric surface, a negative second lens (L2), a negative third lens (L3), and a positive fourth lens (L4) and a second lens group comprising, a positive fifth lens (L5) made of a plastic lens having an aspheric surface, a negative sixth lens (L6), a positive seventh lens (L7), and a positive eighth lens (L8) are successively disposed from the enlargement side, while satisfying the following conditional expressions:-2.5<F.sub.1 /F.sub.5 <-0.3,-2.8<FG.sub.1 /FG.sub.2 <-1.

Abstract: An array of M.times.N actuated mirrors comprises an active matrix, an array of M.times.N elastic members, an array of M.times.N pairs of actuating structures and an array of M.times.N mirrors. Each of the elastic members is provided with a distal and a proximal ends, the proximal end including a first and a second tab portions, the first tab and the second tab portions being separated by a retraction therebetween, the distal end including a protrusion. Each of the actuating structures is located on the first and the second tab portions on each of the elastic members, respectively. Each of the mirrors is formed on top of the elastic members. When the pair of actuating structures deform in response to an electrical signal, the first and the second tab portions tilt while the remainder of the elastic member, and, the mirror formed on top thereof, stays planar, thereby allowing all of the mirrors to reflect the light beams.

Abstract: An image display apparatus comprises an image display device for emitting a light beam to display an image, and an observation optical system for guiding the light beam from the image display device to the pupil of an observer. The observation optical system has at least a concave, reflective surface and a convex, reflective surface in order from the pupil side of the observer along an optical axis of the light beam directed from the image display device to the pupil. The concave, reflective surface is located near the pupil.

Abstract: A surface wave motor built-in lens barrel has a manual focus adjusting mode and an autofocus adjusting mode. The lens barrel comprises a photographing optical system, a fixed drum, a surface wave motor so fitted to the fixed drum as to be rotatable about an optical axis and having a fixed member capable of generating surface waves and a moving member friction-contacting the fixed member, rotating about the optical axis by the surface waves and thereby capable of moving the photographing optical system and a manual operation member capable of moving the photographing optical system by an outside operation. The photographing optical system is, in the manual focus adjusting mode, moved when the moving member and the fixed member of the surface wave motor become integral and rotated interlocking with a manual operation of the manual operation member.

Abstract: An image display apparatus, e.g., a head-mounted image display apparatus, which uses a compact optical system and yet has minimal aberrations and a large exit pupil diameter. An image displayed on a liquid crystal display device (2) is projected as an enlarged image in a user's eyeball by a convex lens (3). Prism arrays (13 and 14) having the same vertex angle are disposed in parallel to each other between the convex lens (3) and an exit pupil (6) so that the array directions coincide with each other. A parallel beam of light passed through the convex lens (3) has a pupil diameter (a) determined by the numerical aperture of an illumination system (1). The parallel beam first enters the prism array (13) and separates into light beams traveling in four different directions by the prism refracting action. These light beams then enter the prism array (14), which has the same vertex angle as that of the prism array (13). Consequently, the light beams are refracted again to become parallel to each other.

Abstract: A zoom lens has a first lens unit which is fixed in position during zooming and has a positive refractive power, a second lens unit which is movable upon zooming and has a negative refractive power, a third lens unit which is fixed in position during zooming and has a positive refractive power, a fourth lens unit which is movable upon zooming and has a negative refractive power, and a fifth lens unit which is fixed in position during zooming and has a positive refractive power. Upon zooming from the wide-angle end to the telephoto end, the second lens unit is unidirectionally moved from the object side to the image side along the optical axis. The fourth lens unit is moved along the optical axis from the object side to the image side within the range from the wide-angle end to the middle position between the wide-angle and telephoto ends, and is moved along the optical axis from the image side to the object side within the range from the middle position to the telephoto end.

Abstract: A receptacle has an end surface supported along a plane extending at right angles to the axis of the receptacle and a contact surface at the other end. The contact surface also extends at right angles to the axis of the receptacle. A receptacle holder has a recess within which the receptacle is received. An adjusting mechanism is devised to adjust radial position of the receptacle. A lens holder is attached to the other end of the receptacle holder. A slide member has a sliding surface in surface contact with the contact surface of the receptacle. The slide plate is urged toward the one end of the receptacle so as to bring the sliding surface into contact with the contact surface of the receptacle. An optical fiber is inserted into the receptacle through a ferrule. If the optical fiber is twisted, the slide plate permits ready rotation of the receptacle in a torsional direction so as to prevent the optical fiber from being subjected to torsional stress.

Abstract: The image source of a head up display for a motor vehicle is illuminated from a remote high intensity source using fiber optics. The HUD image source and optics are under the dash pad of the vehicle and include color LCD or color filtered image source. The image is lighted by a high intensity light source which yields a bright projected image and which generates substantial heat. The light source includes lamps in a fan-cooled heat sink located in the vehicle engine compartment, for example, and coupled to the image source by fiber optic light guides. The light guides abut the image source to uniformly light small image patterns commensurate with the light guide size, or light spreading techniques are used for larger image patterns.

Abstract: A zoom lens system is composed of a first lens group of a positive power, a second lens group of a negative power, a third lens group of a positive power, and a fourth lens groups of a positive power arranged in this order from the object side, the magnification of said zoom lens system being changed by moving the second and third lens groups relative to each other and to the first and fourth lens groups while the positions of the first and fourth lens groups are fixed, wherein focal lengths of the first to fourth lens groups are defined to satisfy the following conditions:100<f1/fw<5002.3<.vertline.f2.vertline./fw<3.51<f4/f3<2wherein f1, f2, f3 and f4 are the focal lengths of the first to fourth lens groups, respectively; and fw is the focal length of the zoom lens system in a wide-angle terminal.

Abstract: The present invention relates to a projector using laser light, and more particularly to a ring-shaped laser spot capable of forming a projected image having a ring-shaped projected image formed from a diffraction fringe, by interposing a diaphragm between a collimator lens and a target. The collimator lens transmits laser light emitted from a laser light source to the target to form a first projected image on the target. The diaphragm shapes the laser light transmitted through the collimator lens to form a ring-shaped second projected image as a diffraction fringe on the target.