Abstract: Provided are an imaging lens, which is a wide-angle imaging lens and is capable of satisfactorily correcting various aberrations, and an imaging apparatus which includes this imaging lens. The imaging lens consists of, in order from an object side: a first lens L1 that has a negative refractive power; a second lens L2 that has a negative refractive power; a third lens L3 that has a positive refractive power; a fourth lens L4 that has a negative refractive power; a fifth lens L5 that has a positive refractive power; a sixth lens L6 that has a positive refractive power; and a seventh lens L7 that has a negative refractive power. The following conditional expression (1) is satisfied. ?2<f/f12<?1.

Abstract: An imaging lens consists of, in order from the object side, a negative first lens, a positive second lens, a positive third lens, a negative fourth lens, a positive fifth lens, and a positive sixth lens. The imaging lens satisfies the condition expressions below: f1/f<?1.68??(1-2), ?0.7<f4/f??(2), ?0.6<(R3+R4)/(R3?R4)<2.2??(11-2), and 0.5<f2/f3<4.0??(12), where f1 to f4 are focal lengths of the first to the fourth lenses, f is a focal length of the entire system, R3 is a radius of curvature of the object-side surface of the second lens, and R4 is a radius of curvature of the image-side surface of the second lens.

Abstract: Provided are an imaging lens, which is a wide-angle imaging lens and is capable of satisfactorily correcting various aberrations, and an imaging apparatus which includes this imaging lens. The imaging lens consists of, in order from an object side: a first lens L1 that has a negative refractive power; a second lens L2 that has a negative refractive power; a third lens L3 that has a positive refractive power; a fourth lens L4 that has a negative refractive power; a fifth lens L5 that has a positive refractive power; a sixth lens L6 that has a positive refractive power; and a seventh lens L7 that has a negative refractive power. The following conditional expression (1) is satisfied. ?2<f/f12<?1.

Abstract: An imaging lens substantially consists of negative first lens, positive second lens, negative third lens, positive fourth lens, positive fifth lens, and negative sixth lens in this order from an object side. At least one of second lens through sixth lens satisfies the following conditional expression (1), and the imaging lens, as a whole, satisfies the following conditional expression (2): (1/?i)×(f/fi)<0??(1); and ?(1/?i)×(f/fi)<0 (i=1 through 6)??(2).

Abstract: An imaging lens consists of, in order from the object side, a negative first lens, a positive second lens, a positive third lens, a negative fourth lens, a positive fifth lens, and a positive sixth lens. The imaging lens satisfies the condition expressions below: f1/f<?1.68??(1-2), ?0.7<f4/f??(2), ?0.6<(R3+R4)/(R3?R4)<2.2??(11-2), and 0.5<f2/f3<4.0??(12), where f1 to f4 are focal lengths of the first to the fourth lenses, f is a focal length of the entire system, R3 is a radius of curvature of the object-side surface of the second lens, and R4 is a radius of curvature of the image-side surface of the second lens.

Abstract: An imaging lens substantially consists of negative first lens, positive second lens, negative third lens, positive fourth lens, positive fifth lens, and negative sixth lens in this order from an object side. At least one of second lens through sixth lens satisfies the following conditional expression (1), and the imaging lens, as a whole, satisfies the following conditional expression (2): (1/?i)×(f/fi)<0??(1); and ?(1/?i)×(f/fi)<0 (i=1 through 6)??(2).

Abstract: An image pickup lens having a four lens configuration in which a bi-concave first lens, a bi-convex second lens, a bi-concave third lens, and a positive fourth lens are disposed in this order from an object side. Here, at least one of the first, second, third, and fourth lenses has an aspherical surface on each side. The image pickup lens satisfies Conditional Expression (1) given below when a refractive index of the second lens with respect to d-line is taken as Nd2. 1.

Abstract: An objective lens for converging light emitted from a light source onto an optical recording medium to record and reproduce information consists of a single lens that has at least one aspheric surface. The following conditional expressions (1) and (2) are satisfied: ?0.90<R1/R2<?0.45??(1) 0.70<d/f<1.40??(2) where R1 denotes a radius of curvature (mm) of a light source side surface near an optical axis, R2 denotes a radius of curvature (mm) of an optical recording medium side surface near the optical axis, d denotes a thickness (mm) on an optical axis, and f denotes a focal length (mm).

Abstract: Disclosed is an imaging lens capable of improving weatherability, reducing performance degradation, and obtaining an optical performance excellent across a wide wavelength region from the visible wavelength region to the near-infrared wavelength region. An imaging lens for forming an image of visible and near-infrared light includes, in order from the object side: a front group that has a positive power; an aperture stop; and a rear group that has a negative power. In the imaging lens, the rear group includes a negative meniscus lens that is disposed closer to the object side and has a surface convex toward the object side, and a biconvex lens that is disposed closer to the image side. In addition, all the lenses constituting the imaging lens are single lenses.

Abstract: An image pickup lens having a four lens configuration in which a bi-concave first lens, a bi-convex second lens, a bi-concave third lens, and a positive fourth lens are disposed in this order from an object side. Here, at least one of the first, second, third, and fourth lenses has an aspherical surface on each side. The image pickup lens satisfies Conditional Expression (1) given below when a refractive index of the second lens with respect to d-line is taken as Nd2. 1.

Abstract: An objective lens consists of a single lens element, and has a light source side surface formed into a convex surface having a large curvature and an optical recording medium side surface has a small curvature. The both surfaces are aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3): 0.7<NA<0.98??(1) 0.70<d/f<1.40??(2) 0.48<X<0.55??(3). where NA denotes a numerical aperture of the objective lens on an optical recording medium side, d denotes a thickness of the objective lens on an optical axis in mm, and f denotes a focal length of the objective lens in mm. X is equal to (X1?X2)·(n?1)/(NA·f), where X1 and X2 denote values relating to sag amounts in the respective surfaces, and n denotes a refractive index.

Abstract: An imaging lens includes, in order from an object side, a positive first lens group, a stop, and a positive second lens group. The first lens group includes, in order from the object side, a first lens, which is a negative meniscus lens having a convex object-side surface, and a second lens having a positive power and including a convex image-side surface. The second lens group includes, in order from the object side, a third lens having a negative power and including a concave object-side surface, a fourth lens having a positive power and including a convex image-side surface, a fifth lens, which is a biconvex lens, and a sixth lens, which is a meniscus lens having a negative power and including a convex surface facing an image side. Each of the first to sixth lenses is a single spherical glass lens.

Abstract: An objective lens consists of a single lens element. A light source side surface is formed into a convex surface having a large curvature, and an optical recording medium side surface has a small curvature. The both surfaces are formed into aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3): 0.70<NA<0.98??(1) 0.70<d/f<3.00??(2) 0.50<g/d<0.80??(3) where NA denotes a numerical aperture of the objective lens on an optical recording medium side, d denotes a thickness, in mm, of the objective lens on an optical axis, and g is a distance, in mm, from a tangential plane that is perpendicular to the optical axis and is tangent to a vertex of the light source side surface of the objective lens, to a center of gravity of the objective lens.

Abstract: An objective lens for converging light emitted from a light source on an optical recording medium to record and reproduce information consists of a single lens having at least one aspheric surface. The following conditional expressions (1) to (3) are satisfied: N?1.75??(1) 0.5<f/f1<0.6??(2) 0.8<d/(NA·De)<1.0??(3) where N denotes a refractive index, f denotes a focal length (mm), f1 denotes a focal length (mm) of a light source side surface, d denotes a thickness (mm) on an optical axis, NA denotes a numerical aperture on an optical recording medium side, and De denotes an effective aperture (mm) of the light source side surface.

Abstract: A laser beam output from a semiconductor laser light source 1 is transmitted through a cover glass 2 in the optical axis Z direction, is incident on a molded lens 4 in a state of divergent rays, is converted into convergent rays by the molded lens 4, and is applied onto a recording face 5 of the optical recording medium. A diaphragm 3 is arranged. An area of each lens surface onto which a luminous flux of the laser beam restricted by the diaphragm 3 is applied corresponds to an effective area. The following expression (1) is satisfied: d1?d0?0.04 mm??(1) where d0 denotes an effective aperture of one of the lens surfaces, and d1 denotes an outer diameter of the one of the lens surfaces.

Abstract: An imaging lens includes, in order from an object side, a first lens having a negative power and including a concave image-side surface, a second lens having a positive power, a stop, a third negative lens, which is a biconcave lens, a fourth lens having a positive power, and a fifth lens having a positive power and including a convex image-side surface. The imaging lens satisfies the following conditional expressions: 0.18<(D4+D5)/f<0.44, and 0.18<D1/f where f denotes a focal length of an entire lens system, D1 denotes a thickness of a center of the first lens, D4 denotes a distance from an image-side surface of the second lens to the stop on an optical axis, and D5 denotes a distance from the stop to an object-side surface of the third lens on the optical axis.

Abstract: An imaging lens includes, in order from an object side, a first lens group having a positive power, an aperture diaphragm, and a second lens group having a positive or negative power. The first lens group includes, in order from the object side, a first lens which is a biconcave lens, a second lens that has a positive power and includes a convex image-side surface, and a third lens that has a positive power and includes a convex object-side surface. The second lens group includes, in order from the object side, a fourth lens that has a negative power and includes a concave image-side surface, and a fifth lens which is a biconvex lens. Each of the first to fifth lenses is a single spherical glass lens.

Abstract: Disclosed is an imaging lens capable of improving weatherability, reducing performance degradation, and obtaining an optical performance excellent across a wide wavelength region from the visible wavelength region to the near-infrared wavelength region. An imaging lens for forming an image of visible and near-infrared light includes, in order from the object side: a front group that has a positive power; an aperture stop; and a rear group that has a negative power. In the imaging lens, the rear group includes a negative meniscus lens that is disposed closer to the object side and has a surface convex toward the object side, and a biconvex lens that is disposed closer to the image side. In addition, all the lenses constituting the imaging lens are single lenses.

Abstract: An imaging lens includes, in order from an object side, a positive first lens group, a stop, and a positive second lens group. The first lens group includes, in order from the object side, a first lens, which is a negative meniscus lens having a convex object-side surface, and a second lens having a positive power and including a convex image-side surface. The second lens group includes, in order from the object side, a third lens having a negative power and including a concave object-side surface, a fourth lens having a positive power and including a convex image-side surface, a fifth lens, which is a biconvex lens, and a sixth lens, which is a meniscus lens having a negative power and including a convex surface facing an image side. Each of the first to sixth lenses is a single spherical glass lens.

Abstract: An imaging lens includes, in order from an object side, a first lens group having a positive power, an aperture diaphragm, and a second lens group having a positive or negative power. The first lens group includes, in order from the object side, a first lens which is a biconcave lens, a second lens that has a positive power and includes a convex image-side surface, and a third lens that has a positive power and includes a convex object-side surface. The second lens group includes, in order from the object side, a fourth lens that has a negative power and includes a concave image-side surface, and a fifth lens which is a biconvex lens. Each of the first to fifth lenses is a single spherical glass lens.