Abstract: A zoom lens comprises in order from an object side, a first lens unit having a positive refractive power, and at the time of zooming from a wide angle end to a telephoto end, the first lens unit moves, and the zoom lens satisfies the following conditional expression (1). FNO(W)<1.64??(1) where, FNO(W) denotes an F-number of the zoom lens at the wide angle end.

Abstract: A zoom lens comprises in order from an object side a first lens unit having a positive refractive power. The first lens unit consist one positive lens. The zoom lens satisfies the following conditional expressions (1) and (2). Fno(W)<2.7??(1) 3.1<ft/fw where, Fno(W) denotes an F-number of the zoom lens at a wide angle end, ft denotes a focal length at a telephoto end of the overall zoom lens system, and fw denotes a focal length at the wide angle end of the overall zoom lens system.

Abstract: A zoom lens comprises, in order from its object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. The first lens unit comprises a first lens having a negative refractive power and a second lens having a positive refractive power. The zoom lens satisfies the following conditional expressions (1), (2), and (3): n1n?1.70??(1), n1p?1.70??(2), and |?1n??1p?31??(3), where n1n is the refractive index of the first lens having a negative refractive power in the first lens unit for the d-line, ?1n is the Abbe constant of the first lens having a negative refractive power in the first lens unit, n1p is the refractive index of the second lens having a positive refractive power in the first lens unit for the d-line, and ?1p is the Abbe constant of the second lens having a positive refractive power in the first lens unit.

Abstract: A zoom lens includes in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power, and at the time of zooming, the first lens unit moves, and the zoom lens satisfies the following conditional expressions (1-1a), (1-2a), and (1-3a). 0.43<(?2T/?2W)/(?3T/?3W)<0.68??(1-1a) 0.4<(?1G/f1)/(?4G/f4)<2.3??(1-2a) 2.1<f3/fW<4.

Abstract: A zoom lens includes in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power, and at the time of zooming, the first lens unit moves, and the zoom lens satisfies the following conditional expressions (1-1a), (1-2a), and (1-3a). 0.43<(?2T/?2W)/(?3T/?3W)<0.68??(1-1a) 0.4<(?1G/f1)/(?4G/f4)<2.3??(1-2a) 2.1<f3/fW<4.

Abstract: A zoom lens comprises in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power, and the third unit having a positive refractive power comprises in order from the object side, a first lens component having a positive refractive power, and a second lens component having a negative refractive power in which, a lens having a positive refractive power and a lens having a negative refractive power are cemented, and the zoom lens satisfies the following conditional expressions (1), (2), and (3) 1.4<|f3—2p/f3—2n|<2.6??(1) nd3—2p?nd3—2n?0??(2) nd3—2n?1.

Abstract: A zoom lens comprises in order from an object side a first lens unit having a positive refractive power. The first lens unit consist one positive lens. The zoom lens satisfies the following conditional expressions (1) and (2). Fno(W)<2.7??(1) 3.1<ft/fw where, Fno(W) denotes an F-number of the zoom lens at a wide angle end, ft denotes a focal length at a telephoto end of the overall zoom lens system, and fw denotes a focal length at the wide angle end of the overall zoom lens system.

Abstract: An image forming optical system of the present invention is characterized by comprising three groups having, in order from an object side to an image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, or four groups with one more lens group added to the image side, the first lens group comprises one lens component facing its concave surface toward the object side, the second lens group comprises a single lens having a positive refractive power and a cemented lens having a negative refractive power as a whole, and the third lens group comprises a lens component having a positive refractive power, wherein upon zooming from the wide-angle end toward the telephoto side, the amount of movement of the first lens group in the optical axis direction in an area, where the focal length of the entire image pickup optical system is 3.

Abstract: A zoom lens comprises in order from an object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a negative refractive power. The second lens unit comprises in order from the object side, a positive lens, a negative lens, and a positive lens. At the time of zooming from a wide angle end to a telephoto end, the first lens unit moves toward the object side, and the fourth lens unit moves, and a distance between the first lens unit and the second lens unit decreases monotonically, a distance between the second lens unit and the third lens unit increases monotonically, and a distance between the third lens unit and the fourth lens unit increases monotonically.

Abstract: A zoom lens comprises in order from an object side, a first lens unit, a second lens unit, a third lens unit, a fourth lens unit, and a fifth lens unit having, respectively, a positive, negative, positive, negative, and positive refractive power. At the time of zooming from a wide angle end to a telephoto end, the first, third, and fourth lens units move toward the object side. A distance between the first and second lens units increase, a distance between the second and third lens units decrease, a distance between the third lens unit and the fourth lens unit changes, and a distance between the fourth lens unit and the fifth lens unit increases. The zoom lens satisfies the following expressions: 1.54<?4T/?4w<3.0??(1a) 1.0<?3T/?3w<5.0??(2) 1.0<?5T/?5w<3.0??(3).

Abstract: A zoom lens with a bent optical path includes, in order from the object side to the image side, a first lens unit including the reflecting member and having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a positive refractive power. During zooming from the wide angle end to the telephoto end, the second lens unit moves closer to the first lens unit only toward the object side, the third lens unit moves in such a way that it becomes closest to the second lens unit at an intermediate focal length position in the course of zooming as compared to the state at the wide angle end and the state at the telephoto end, and the fourth lens unit moves. The zoom lens satisfies a certain condition.

Abstract: A zoom lens comprises in order from an object side, a first lens unit, a second lens unit, a third lens unit, a fourth lens unit, and a fifth lens unit having, respectively, a positive, negative, positive, negative, and positive refractive power. At the time of zooming from a wide angle end to a telephoto end, the first, third, and fourth lens units move toward the object side. A distance between the first and second lens units increase, a distance between the second and third lens units decrease, a distance between the third lens unit and the fourth lens unit changes, and a distance between the fourth lens unit and the fifth lens unit increases. The zoom lens satisfies the following expressions: 1.54<?4T/?4w<3.0??(1a) 1.0<?3T/?3w<5.0??(2) 1.0<?5T/?5w<3.0??(3).

Abstract: A zoom lens comprises in order from an object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a negative refractive power. The second lens unit comprises in order from the object side, a positive lens, a negative lens, and a positive lens. At the time of zooming from a wide angle end to a telephoto end, the first lens unit moves toward the object side, and the fourth lens unit moves, and a distance between the first lens unit and the second lens unit decreases monotonically, a distance between the second lens unit and the third lens unit increases monotonically, and a distance between the third lens unit and the fourth lens unit increases monotonically.

Abstract: A zoom lens comprises, in order from its object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. The first lens unit comprises a first lens having a negative refractive power and a second lens having a positive refractive power. The zoom lens satisfies the following conditional expressions (1), (2), and (3): n1n?1.70??(1), n1p?1.70??(2), and |?1n??1p?31??(3), where n1n is the refractive index of the first lens having a negative refractive power in the first lens unit for the d-line, ?1n is the Abbe constant of the first lens having a negative refractive power in the first lens unit, n1p is the refractive index of the second lens having a positive refractive power in the first lens unit for the d-line, and ?1p is the Abbe constant of the second lens having a positive refractive power in the first lens unit.

Abstract: An image forming optical system of the present invention is characterized by comprising three groups having, in order from an object side to an image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, or four groups with one more lens group added to the image side, the first lens group comprises one lens component facing its concave surface toward the object side, the second lens group comprises a single lens having a positive refractive power and a cemented lens having a negative refractive power as a whole, and the third lens group comprises a lens component having a positive refractive power, wherein upon zooming from the wide-angle end toward the telephoto side, the amount of movement of the first lens group in the optical axis direction in an area, where the focal length of the entire image pickup optical system is 3.

Abstract: The invention relates to an optical system that is capable of providing a zoom lens having improved image-formation capability with a reduced number of lenses, and fabricating a slim yet high-performance digital or video camera. The optical system comprises a cemented lens having a cementing surface on its optical axis. Air contact surfaces on the light ray entrance and exit sides of the cemented lens G2 are aspheric, and at least one cementing surface in the cemented lens G2 satisfies condition (1). 6.4<|(r/R)|??(1) Here r is the axial radius of curvature of the cementing surface, and R is the maximum diameter of the cementing surface.

Abstract: A zoom lens system having, in order from an object side, a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and a fourth lens unit having a positive refractive power, wherein during magnification change from a wide-angle end to a telephoto end, an interval between the first lens unit and the second lens unit, an interval between the second lens unit and the third lens unit and an interval between the third lens unit and the fourth lens unit change.

Abstract: The present invention relates to a waste disposing apparatus that, rather than using incineration, uses a system wherein heat is applied to a magnetic field generated by compounded granulated ores to promote the occurrence and activation of plasma, resulting in the maintenance of a high temperature in the disposing apparatus that is sufficient to subject to a high heat consumption disposing the waste placed therein.

Abstract: The invention relates to an optical system that is capable of providing a zoom lens having improved image-formation capability with a reduced number of lenses, and fabricating a slim yet high-performance digital or video camera. The optical system comprises a cemented lens having a cementing surface on its optical axis. Air contact surfaces on the light ray entrance and exit sides of the cemented lens G2 are aspheric, and at least one cementing surface in the cemented lens G2 satisfies condition (1). 6.4<|(r/R)| ??(1) Here r is the axial radius of curvature of the cementing surface, and R is the maximum diameter of the cementing surface.

Abstract: A zoom lens system having, in order from an object side, a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and a fourth lens unit having a positive refractive power, wherein during magnification change from a wide-angle end to a telephoto end, an interval between the first lens unit and the second lens unit, an interval between the second lens unit and the third lens unit and an interval between the third lens unit and the fourth lens unit change.