Abstract: An imaging lens includes a first lens having negative refractive power; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having positive refractive power; and a fifth lens having negative refractive power. The first lens has object-side and image plane-side surfaces with positive curvature radii. The second lens has object-side and image plane-side surfaces with positive curvature radii. The third lens has an object-side surface with a positive curvature radius and an image plane-side surface with a negative curvature radius. The fourth lens has an object-side surface with a positive curvature radius and an image plane-side surface with a negative curvature radius. The fifth lens has object-side and image plane-side surfaces with negative curvature radii. The first to fifth lenses have specific Abbe's numbers to satisfy specific conditions. The fifth lens has a specific focal length to satisfy specific conditions.

Abstract: An image pickup lens includes an aperture stop, a first lens with positive refractive power having a convex object-side surface, a second lens with negative refractive power having a concave image-side surface, a third lens with positive refractive power having a convex image-side surface, a fourth lens with negative refractive power as a double-sided aspheric lens having a concave object-side surface, and a fifth lens with negative refractive power of a meniscus shape as a double-sided aspheric lens having a concave image-side surface, wherein the fifth lens is designed so that the negative refractive power weakens as the distance from the optical axis increases, and wherein the following conditional expression (1) is satisfied: 0.55<f1/f<1.0??(1) where f represents a focal length of an overall image pickup lens, and f1 represents a focal length of the first lens.

Abstract: An imaging lens includes a first lens having negative refractive power; a stop; a second lens having positive refractive power; a third lens having negative refractive power; and a fourth lens having positive refractive power, arranged in the order from an object side to an image plane side. The first lens has an object-side surface and an image plane-side surface, curvature radii of which are both negative. The second lens has an object-side surface and an image plane-side surface, curvature radii of which are both positive. The third lens has an object-side surface and an image plane-side surface, curvature radii of which are both negative. The fourth lens has an object-side surface, a curvature of which is positive.

Abstract: A compact low-cost imaging lens unit for a solid-state image sensor which corrects various aberrations adequately and produces a high-resolution high-definition image. The components of the unit are arranged from an object side to an image side in the following order: an aperture stop, a first lens with positive refractive power having a convex surface facing the object side, a second lens with negative refractive power having a convex surface facing the object side near an optical axis, a third lens with negative refractive power having a convex surface facing the object side near the optical axis, a fourth lens as a meniscus lens with positive refractive power having a convex surface facing the image side near the optical axis; and a fifth lens with negative refractive power having a concave surface facing the image side near the optical axis.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; and a fourth and a fifth lens having negative refractive power. The first lens is formed so that a curvature radius of an object-side surface is positive and the second lens is formed so that a curvature radius of an object-side surface and a curvature radius of an image plane-side surface are positive. The third lens is formed so that a curvature radius of an object-side surface is positive, and the fifth lens is formed so that a curvature radius of an object-side surface and a curvature radius of an image plane-side surface are both positive. An Abbe's number from the first and the third to the fifth lens is greater than 45, and an Abbe's number of the second lens is less than 35.

Abstract: An imaging lens includes a positive first lens; a negative second lens with a meniscus lens shape directing a convex surface thereof to an object side near an optical axis; a positive third lens; a negative fourth lens with a meniscus lens shape directing a concave surface thereof to the object side near the optical axis; a negative fifth lens with a meniscus lens shape directing a convex surface thereof to the object side near the optical axis, arranged in this order from the object side.

Abstract: A compact low-cost imaging lens unit for a solid-state image sensor which corrects various aberrations adequately and produces a high-resolution high-definition image. The components of the unit are arranged from an object side to an image side in the following order: an aperture stop, a first lens with positive refractive power having a convex surface facing the object side, a second lens with negative refractive power having a convex surface facing the object side near an optical axis, a third lens with negative refractive power having a convex surface facing the object side near the optical axis, a fourth lens as a meniscus lens with positive refractive power having a convex surface facing the image side near the optical axis; and a fifth lens with negative refractive power having a concave surface facing the image side near the optical axis.

Abstract: In order to provide a lens module having a simply structured lens drive mechanism that is capable of stabilizing the moving speed of an optical lens system, the lens module has a structure wherein a lens holder (to which no illustrated optical lens system is mounted) (6) that mounts a moving body (5) attractable to a magnet (4) is mounted on a housing (7) using guide pins (8), and wherein one side of a piezoelectric ceramic element (3) is adhered to the magnet (4) in the displacement generating direction (longitudinal direction) of the piezoelectric ceramic element 3, and the other side thereof is adhered to the housing (7), with the moving body (5) and the magnet (4) being attracted by a magnetic force. The lens holder (6) supporting the moving body (5) is movably supported by the guide pins (8). The magnetization direction of the magnet (4) is substantially orthogonal to an optical axis direction of the optical lens system and is a radial direction of the optical lens system.

Abstract: The present invention provides a growth hormone secretion regulator or an anti-aging agent comprising aspartic acid and valine as active ingredients. The present invention also provides a pharmaceutical, food, nutritional supplement (supplement), or feeding stuff comprising the growth hormone secretion regulator or anti-aging agent.

Abstract: An optical isolator comprises a Faraday rotator for non-reciprocally rotating a polarization plane of light, and two polarizers joined to both sides of the Faraday rotator. Each of the polarizers is processed into a spherical surface to form a lens for converging or diverging light passing through the polarizer to form a real image or a virtual image. The optical isolator is formed by joining the two polarizers with the Faraday rotator interposed therebetween and has a generally spherical shape as a whole. The two polarizers may be made of materials different in refractive index from each other.

Abstract: A wave front interferometer for determining the shape of a surface from interference fringes has a light source which projects a light beam through a beam splitter disposed in an optical path between the light source and an optical surface whose shape is to be determined. The beam splitter bends a phase conjugate wave to become incident on the optical surface and to be reflected as a reflected beam. A phase conjugate mirror disposed in the optical path receives the light beam along a beam path through the beam splitter and reflects the light beam as the phase conjugate wave. The phase conjugate mirror reflects the light beam back along the same beam path so that the distance of the focus point of the light beam reflected from the phase conjugate mirror increases as the distance between the light source and the beam splitter and/or the phase conjugate mirror increases, so that either a convex or concave surface having a large radius of curvature can be measured.