Abstract: An image projection apparatus has a corrector that corrects angle distribution of illumination light such that, let, in a comparison in traveling direction between, of diffracted light resulting from light rays with the wavelengths ?1 and ?2 along the illumination optical axis being diffracted on an on-state digital micromirror device, ?1 diffracted light traveling in a direction closest to a traveling direction of the mirror-reflected light and ?2 diffracted light traveling in a direction closest to the traveling direction of the mirror-reflected light, the ?1 diffracted light be diffracted to a position farther away from the mirror-reflected light than the ?2 diffracted light, the angle distribution of the illumination light includes at least an angle distribution that fulfills conditional formula (1): F?2<F?1, where F?1 and F?2 represent F-numbers of illumination light with the first and second wavelengths ?1 and ?2, respectively.

Abstract: A single-focal-length imaging lens system achieves focusing by, while keeping first and third lens groups stationary relative to the image plane, moving a second lens group along the optical axis. The second lens group includes a positive lens element. The third lens group includes an aspherically shaped lens element having an inflection point at a position other than the intersection with the optical axis. The first and second air lenses formed by the intervals between the first and second and between the second and third lens groups have negative and positive refractive powers respectively. The conditional formula 0?|Fi1/Fi2|?|Fm1/Fm2|?10 is fulfilled (Fi1 and Fi2 representing the focal lengths of the first and second air lenses, respectively, when focusing on the infinite object distance; Fm1 and Fm2 representing the focal lengths of the first and second air lenses, respectively, when focusing on the closest object distance).

Abstract: An objective lens for an optical pickup device is characterized in that compatibility of three types of optical discs, which are a BD, a DVD, and a CD, may be realized by a common objective lens, and a flare can be created by providing an over-spherical aberration when a third optical disc is used from a size relationship between a pitch on a central region side and a pitch on an intermediate region side across a boundary and a relationship of a direction of a step in the base structures superimposed in a central region and an intermediate region of the objective lens.

Abstract: A lens barrel and a lens unit each include a lens drive operation member that drives a lens holding member holding a movable lens group, in an axial direction by a rotation operation of a rotating member. This lens drive operation member has a body disposed so as to be rotatable about an axis of a fixed barrel and so as not to be movable in the axial direction and connected to the rotating member by a connecting portion, and the connecting portion includes at least two connecting members, that is, a first connecting member formed integrally with the body, and a second connecting member formed separately from the body.

Abstract: A zoom lens system has, in order from the enlargement side, a first lens group that remains stationary during zooming and that has a negative optical power and a plurality of lens groups that move during zooming. The first lens group includes three lens groups each having a negative optical power, namely a 1a-th lens group, a 1b-th lens group, and a 1c-th lens group. The 1a-th lens group remains stationary during focusing and includes at least one positive lens element. The 1b-th lens group moves toward the reduction side during focusing from infinity to a close distance. The 1c-th lens group moves toward the enlargement side during focusing from infinity to a close distance.

Abstract: A lens barrel and a lens unit of the present invention each include a cam drum having a cam groove, a lens holding frame for holding a moving lens group, and a cam follower installed on an outer periphery of the lens holding frame. The cam groove has two groove side walls, and an inclined wall that extends outward in a radial direction of the cam drum from one of the two groove side walls to the other thereof, and the cam follower has a contact member that contacts the inclined wall and a cam follower main unit respectively, and a biasing member that biases the contact member outward in the radial direction.

Abstract: To provide an image pickup lens with a five-lens configuration in which aberrations are corrected favorably despite its compactness. An image pickup lens 10 includes a first lens L1 having a positive refractive power and having a convex face directed to an object side, a second lens L2 of a meniscus shape having a negative refractive power and having a concave face directed to an image side, a third lens L3 having a positive refractive power, a fourth lens L4 having a positive refractive power and having a convex face directed to the image side, and a fifth lens L5 having a negative refractive power and having a concave face directed to the image side, in this order from the object side. Here, the focal length of the fifth lens, the focal length of the entire system of the image pickup lens, and an air separation on an optical axis between the fourth lens and the fifth lens satisfy predetermined conditions.

Abstract: Provided is a cellulose acetate film which has excellent retardation properties and exhibits low haze even under high-temperature and high-humidity conditions and which, in an alkaline saponification step, causes little dissolution of the film itself or additives in a saponifying liquid. The cellulose acetate film is characterized by comprising: a cellulose acetate which has an acetyl substitution degree of 2.0 to 2.5; and 5 to 15% by mass (relative to the cellulose acetate) of a component which contains a compound represented by general formula (1) wherein m is 0 and a compound represented thereby wherein in is more than 0 at a ratio of 45:55 to 0:100.

Abstract: An imaging device having an optical imaging system which has a parallel plate which is transparent at least in a visible light region, is joined by adhesives and is held on a holding member, wherein the holding member including: an opening section which is provided in order to pass light rays from the optical imaging system; a holding surface for holding a periphery of the parallel plate, formed around the opening section in a square shape, and intersecting perpendicularly to an optical axis of the optical imaging system; a side wall which is provided to stand parallel to the optical axis at an outside with respect to the opening section of the holding surface; and an adhesive collecting section which is arranged in each of four corners of the holding surface and is hollowed from the holding surface.

Abstract: Provided with the following glass components: 8 to 19.5% B2O3, 4.5 to 9% SiO2, 0 to 10% GeO2, 7 to 12.5% BaO, 0 to 14% MgO, 0 to 0.4% Li2O, 15 to 34% La2O3, 3.5 to 10% Y2O3, 8 to 13.5% TiO2, 0 to 7% ZrO2, 0 to 11% Nb2O5, and 1 to 9% WO3 by weight, wherein B2O3/SiO2 is at least 1.0, La2O3+Y2O3+ZrO2+Nb2O5+WO3 is no more than 54%, and B2O3+SiO2+GeO2+BaO+MgO+Li2O+La2O3+Y2O3+TiO2+ZrO2+Nb2O5+WO3 is at least 98%.

Abstract: A zoom lens system used in a spectrum region including visible light has movable lens groups moved for zooming, and has, in a movable lens group, a negative lens element made of a material fulfilling the conditional formulae Vd<55 and 0.0018×Vd+P<0.65 and, in a movable lens group, a positive lens element made of a material fulfilling the conditional formulae 60<Vd, 0.645<0.0018×Vd+P, and 9×10?6<dN/dT, where Vd is the Abbe number for a d-line; P=(Ng?NF)/(NF?NC); Ng, NF, and NC are the refractive indices for the g-, F-, and C-lines respectively; and dN/dT is the variation rate in refractive index accompanying variation in room temperature. The negative and positive lens elements move in the same direction during zooming.

Abstract: Disclosed is an imaging lens unit that prevents the detachment of a cover from a holder. The imaging lens unit (200) is provided with a combination lens (6) and an external covering that is formed from at least the holder (2) and the cover (4) and covers the combination lens (6) from the outside, wherein the holder (2) and the cover (4) are connected by means of fitting members (70) that are integrally formed from a resin material and have, on both ends, a first fitting (78) that fits with a section of the holder (2) and a second fitting (80) that fits with a section of the cover (4).

Abstract: An image-capturing lens includes, in order from an object side: a meniscus-shaped first lens which has positive power near an optical axis; a second lens which has positive power near the optical axis and has negative power in the periphery of the second lens; and a meniscus-shaped third lens. The image-capturing lens satisfies the following conditional formulas: TL/f<1.10, 2.00<(r2+r1)/(r2?r1)<4.00, and 0.07<D2/f<0.19, where TL: the air-converted distance from the object-side surface of the first lens to the image-side surface thereof, f: the focal length of the entire system, r2: the radius of curvature of the first lens on the image side thereof, r1: the radius of curvature of the first lens on the object side thereof, D2: the distance between the first lens and the second lens.

Abstract: Disclosed is an image pickup device, by which cut resistance at the time of cutting a wafer lens is reduced, high production efficiency is maintained, and excellent optical characteristics are obtained. The image pickup device has a first lens block, a second lens block, a spacer, and a sensor unit. The side surface section of the first lens block, the side surface section of the second lens block, and the side surface section of the spacer are formed on the same plane. A lens cover that covers the first and the second lens blocks is provided in a step formed by respective side surface sections of the first lens block, the second lens block and the spacer, and the side surface section of the sensor unit.

Abstract: There is provided an image pickup lens having a 6-element structure which has a small size and a sufficiently lens speed of F/2 or less and in which various aberrations are corrected favorably.

Abstract: A zoom lens system is composed of negative, positive, negative, and positive lens groups, of which at least the first to third move during zooming. During zooming 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, and the distance between the third and fourth lens groups increases. The conditional formulae 1.0?|f2/f1|?1.5 and 2.0?|f4/f1|?5.0 are fulfilled (f1, f2, and f4 representing the focal lengths of the first, second, and fourth lens groups).

Abstract: Provided are a method and an apparatus for continuously forming a laminated optical function element sheet which has optical function elements formed on three or more faces by laminating a first optical function element sheet which has an optical function element formed on both of the front and back faces with a second optical function element sheet which has an optical function element formed on at least one of the two faces.

Abstract: Provided is an imaging lens, and also provided are an image pickup apparatus and a portable terminal both equipped with the imaging lens. The imaging lens includes in order: a positive first lens having a convex object-side surface; a negative second lens having a concave image-side surface; a negative meniscus-shaped third lens having a convex object-side surface; a positive fourth lens having a convex image-side surface; and a negative fifth lens having a concave image-side surface. The image-side surface of the fifth lens is aspherical and has an inflection point at a position of the optical axis. The third and the fourth lenses are integrally moved to focus, and the following conditional relation is satisfied: 0.75<f34/f<1.30, where f34 is the combined focal length of the third lens and the fourth lens, and f is the focal length of the entire system of the imaging lens.

Abstract: The disclosed internal focusing large-aperture medium telephoto lens has as lens groups a positive first lens group, a positive second lens group, and a third lens group, in that order from the object side. When focusing on nearby objects, the first lens group and the third lens group have a fixed position relative to the image surface, and the second lens group displaces toward the object side. The second lens group has only one negative lens, and, in order from the object side, has at least a positive lens, a negative lens, and a positive lens. The following expression is fulfilled: ?0.5<(R1+R2)(R1?R2)<?0.1 (wherein, R1: radius of curvature of the object side surface of the negative lens in the second lens group; R2: radius of curvature of the image side surface of the negative lens in the second lens group).

Abstract: A lens barrel and a projector of the invention are provided with a fixed cylinder, and a cam ring mounted on the fixed cylinder. A first projection and a second projection are provided on one of the fixed cylinder and the cam ring, and a first rotation restricting portion and a second rotation restricting portion are provided on the other of the fixed cylinder and the cam ring. The first rotation restricting portion restricts rotation of the cam ring by abutting contact with the first projection when the cam ring is rotated in a first direction, and the second rotation restricting portion restricts rotation of the cam ring by abutting contact with the second projection when the cam ring is rotated in a second direction opposite to the first direction.