Abstract: A radiation imaging apparatus is provided. The apparatus comprises a plurality of pixels and a signal processing unit configured to read out an analog signal from each pixel and output an image signal. The signal processing unit comprises a conversion unit configured to convert the analog signal into a digital signal using an A/D converter such that the digital signals of a first group pixels include a first offset components and the digital signals of a second group pixels include a second offset components, and a digital signal processing unit. The digital signal processing unit calculates a correction value using the digital signals of the first and the second group pixels, and performs correction of reducing an influence caused by the A/D converter in the digital signals of the first group pixels using the correction value, thereby generating the image signal.

Abstract: An imaging lens substantially consists of a negative first lens group and a positive second lens group in this order from the object side. The first lens group substantially consists of only a first lens, which is one biconcave lens. The second lens group substantially consists of, in the following order from the object side: a cemented lens, which is formed by bonding a positive lens and a negative lens, in this order from the object side, and which has a positive refractive power as a whole; an aperture stop; a positive lens; and a negative lens. The imaging lens is configured to satisfy the conditional expressions (1a): 0<f23/f<2.5 and (2a): 0<f45/f<6 at the same time.

Abstract: An imaging lens substantially includes seven lenses, constituted by: a first lens having a positive refractive power and a convex surface toward an image side; a second lens having a negative refractive power; a third lens having a positive refractive power; a fourth lens; a fifth lens having a positive refractive power; a sixth lens; and a seventh lens having a negative refractive power, a concave surface toward an image side, and at least one inflection point in the surface toward the image side; provided in this order from an object side. All of the first lens through the seventh lens are single lenses.

Abstract: An imaging lens provided with a negative first lens group and a positive second lens group arranged in order from the object side. The first lens group is composed of a first group first lens which is a negative single lens, and the second lens group is composed of a positive second group first lens, a positive second group second lens, and a negative second group third lens arranged in order from the object side. The second group first lens is a biconvex lens, the second group second lens is a biconvex lens, the second group third lens is a meniscus lens, an aperture stop is disposed between the second group first and second lenses, and the second group second and third lenses form a cemented lens. The imaging lens satisfies conditional expressions (1): ?0.89?f1/f<0 and (4): 0.3<dt1/f<0.8.

Abstract: The present invention provides an imaging device in which focus movement due to a temperature variation is suppressed and the infiltration of foreign matter such as liquid or dust is prevented. An imaging device 10 is provided with an imaging lens 11, an imaging element 12, and an intermediate member 15. The imaging lens 11 is held by a lens-barrel 13 and forms an image of a photographic subject. The imaging element 12 captures the image of the photographic subject which is formed by the imaging lens 11. The intermediate member 15 has, on the inner-peripheral-surface of one end thereof, a flange portion 15a which comes into contact with the lens-barrel 13, and holds the lens-barrel 13 by joining the front surface 26 of a flange portion 13b of the lens-barrel 13 and the surface 27 on the imaging element 12 side of the flange portion 15a to each other.

Abstract: An imaging lens substantially consists of a negative first lens group and a positive second lens group in this order from the object side. The first lens group substantially consists of only a first lens, which is one biconcave lens. The second lens group substantially consists of, in the following order from the object side: a cemented lens, which is formed by bonding a second lens, i.e., a biconvex lens, and a third lens, i.e., a negative meniscus lens, in this order from the object side, and which has a positive refractive power as a whole; an aperture stop; and a cemented lens that is formed by bonding a fourth lens, i.e., a biconvex lens and a fifth lens, i.e., a negative meniscus lens in this order from the object side and that has a positive refractive power as a whole.

Abstract: An imaging lens is constituted by six lenses, including, in order from the object side to the image side: a positive first lens having a convex surface toward the object side; a negative second lens; a positive third lens, which is a meniscus lens having a convex surface toward the object side; a positive fourth lens; a negative fifth lens having a concave surface toward the object side; and a negative sixth lens, of which the image toward the image side is of an aspherical shape which is concave in the vicinity of the optical axis and convex at the peripheral portion thereof. Conditional formulae related to the focal length f of the entire lens system, the focal length f1 of the first lens, and the focal length f4 of the fourth lens is satisfied. 1.54<f/f4<3 0.

Abstract: An imaging lens is constituted essentially by six lenses, including, in order from the object side to the image side: a first lens having a positive refractive power and a convex surface toward the object side; a second lens having a negative refractive power; a third lens having a positive refractive power and is of a biconvex shape; a fourth lens having a positive refractive power; a fifth lens having a negative refractive power and a concave surface toward the object side; and a sixth lens having a negative refractive power, of which the surface toward the image side is of an aspherical shape which is concave in the vicinity of the optical axis and convex at the peripheral portion thereof. Predetermined conditional formulae are satisfied.

Abstract: An imaging lens provided with a negative first lens group and a positive second lens group arranged in order from the object side. The first lens group is composed of a first group first lens which is a biconcave negative single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens arranged in order from the object side, in which the second group second lens and the second group third lens are cemented together to form a cemented lens. When f1 and f2 are taken as the focal lengths of the first group first lens and the second group first lens respectively, the imaging lens satisfies a conditional expression (4a?): 0.62<|f1/f2|<0.82.

Abstract: An imaging lens substantially consists of, in order from an object side, five lenses of a first lens that has a positive refractive power and has a meniscus shape which is convex toward the object side, a second lens that has a biconcave shape, a third lens that has a meniscus shape which is convex toward the object side, a fourth lens that has a meniscus shape which is convex toward the image side; and a fifth lens that has a negative refractive power and has at least one inflection point on an image side surface. Further, the following conditional expression (1) is satisfied. 1.

Abstract: An imaging lens consists of seven lenses of a first lens that has positive refractive power in the vicinity of an optical axis and a convex surface facing an object side in the vicinity of the optical axis, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens having a concave surface facing an image side in the vicinity of the optical axis, and at least one of the surfaces of which includes an inflection point, and both of the surfaces of which are aspherical, which are in this order from the object side. Further, each of the first lens through the seventh lens is a single lens.

Abstract: An objective optical system includes: a negative first lens group; an aperture stop; and a positive second lens group, provided in this order from an object side. The first lens group includes a first lens, which is a negative single lens, and a cemented lens formed by cementing a positive lens and a negative lens together, provided in this order from the object side. The second lens group includes a fourth lens, which is a positive single lens, and a cemented lens formed by cementing a positive lens and a negative lens together, provided in this order from the object side. The objective optical system satisfies Conditional Formula (1): f1/f<1.1, wherein f1 is the focal length of the lens provided most toward the object side, and f is the focal length of the entire lens system.

Abstract: An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a negative biconcave single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented together to form a cemented lens. The imaging lens is configured to satisfy a conditional expression (3) 0.9<dt3/f<1.3, and further configured to satisfy conditional expression (1) 31<?d2<55 or (1?): 35<?d2 and a conditional expression (2): ?10<?d1??d2<25.

Abstract: An imaging lens substantially consists of five lenses consisting of, in order from the object side: a first lens having a positive refractive power with a convex surface toward the object side; a second lens having a negative refractive power and having a meniscus shape with a convex surface toward the image side; a third lens having a positive refractive power and having a meniscus shape with a convex surface toward the image side; a fourth lens having a positive refractive power and having a meniscus shape with a convex surface toward the image side; and a fifth lens having a negative refractive power, wherein an image-side surface of the fifth lens includes a concave surface and at least one inflection point, wherein a predetermined conditional expression is satisfied.

Abstract: The imaging lens substantially consists of a first lens having a biconvex shape, a second lens having a negative refractive power, a third lens having a negative refractive power and a convex surface that faces the object side, a fourth lens having a positive refractive power, and a fifth lens having a negative refractive power, of which at least one of the object-side surface and the image-side surface has at least one inflection point, in this order from the object side; and wherein conditional expression (1A): ?0.38<f/f45<?0.01 is satisfied. This conditional expression is related to the focal length f of the entire system and the combined focal length f45 of the fourth lens and the fifth lens.

Abstract: An imaging lens substantially includes seven lenses, constituted by: a first lens having a positive refractive power and a convex surface toward an image side; a second lens having a negative refractive power; a third lens having a positive refractive power; a fourth lens; a fifth lens having a positive refractive power; a sixth lens; and a seventh lens having a negative refractive power, a concave surface toward an image side, and at least one inflection point in the surface toward the image side; provided in this order from an object side. All of the first lens through the seventh lens are single lenses.

Abstract: An endoscope objective lens substantially consists of four lens groups consisting of, in order from the object side, a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group. During focusing from the farthest object to the nearest object, the first lens group is fixed, and the second lens group and the third lens group are moved along the optical axis. The third lens group includes a cemented lens that is formed by a positive lens and a negative lens cemented together in this order from the object side, and the cemented surface of the cemented lens is oriented such that the concave surface faces the object side.

Abstract: An objective optical system includes: a first lens group having a negative power; an aperture stop; and a second lens group having a positive power, provided in this order from an object side. The first lens group includes a first lens, which is a negative single lens, and a cemented lens formed by a positive lens and a negative lens, provided in this order from the object side. The second lens group includes a fourth lens, which is a positive single lens, and a cemented lens formed by a positive lens and a negative lens, provided in this order from the object side. The objective optical system simultaneously satisfies Conditional Formulae (1) ?1.5<f123/f<?0.5 and (2) 1.8<f456/f<2.1, wherein f is the focal length of the entire system, f123 is the combined focal system of the first lens group, and f456 is the combined focal length of the second lens group.

Abstract: An imaging lens substantially consists of, in order from an object side, five lenses of a first lens that has a positive refractive power and has a meniscus shape which is convex toward the object side, a second lens that has a biconcave shape, a third lens that has a meniscus shape which is convex toward the object side, a fourth lens that has a meniscus shape which is convex toward the image side; and a fifth lens that has a negative refractive power and has at least one inflection point on an image side surface. Further, the following conditional expression (1) is satisfied. 1.

Abstract: An endoscope objective lens substantially consists of four lens groups consisting of, in order from the object side, a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group. During focusing from the farthest object to the nearest object, the first lens group is fixed, and the second lens group and the third lens group are moved along the optical axis. The third lens group includes a cemented lens that is formed by a positive lens and a negative lens cemented together in this order from the object side, and the cemented surface of the cemented lens is oriented such that the concave surface faces the object side.