Abstract: A zoom lens includes a first lens group having a positive focal length, a second lens group having a negative focal length, a third lens group having a positive focal length, a fourth lens group having a negative focal length which are arranged in order from an object side to an image side, and a diaphragm disposed between the second and third lens groups. During a change of zoom ratio from short to long focus end, the first to fourth lens groups move so that an interval between the first and second lens groups increases, an interval between the second and third lens groups decreases, and an interval between the third and fourth lens groups increases. The first lens group includes first and second negative lenses, a reflective optical element, and at least one positive lens arranged in order from the object side to the image side.

Abstract: A zoom lens comprises a first lens group G1, which includes a negative focal length, a second lens group G2, which includes a positive focal length, a third lens group G3, which includes a negative focal length, a fourth lens group G4, which includes a positive focal length, and a fifth lens group G5, which includes a positive focal length, in order from nearest to furthest from a photographic subject, or with a sixth lens group G6, which includes a negative focal length, installed as an anchored lens group between the fifth lens group and an image site of the camera apparatus.

Abstract: An image reader feeds a document to read document information at a still position from below a glass platen. The image reader is configured to include a document feeder unit feeding a document in a predetermined direction, a glass platen provided below the document feeder unit, an illumination unit provided on or above the glass platen and including a surface light source which is long in a direction orthogonal to the predetermined direction and illuminates the document, and a document reader unit reading document information at a still position from below the glass platen. Such an image reader can illuminate documents efficiently with less electric power and achieve thinning of the illumination unit.

Abstract: A zoom lens includes a first optical system having a positive focal length, the first optical system, a second optical system having a negative focal length, a third optical system having a positive focal length, a fourth optical system having a negative focal length, and a fifth optical system having a positive focal length, which are arranged in order from an object side to an image side and an aperture stop provided at an object side of the third optical system. The following condition is satisfied: 0.5<(T23w/Y?)/(ft/fw)<1.0 where T23w is an interval between the second optical system and the third optical system at the short focus end, Y? is a maximum image height of the zoom lens, ft is a focal length of the zoom lens at the long focus end, and fw is a focal length of the zoom lens at the short focus end.

Abstract: A zoom lens includes a first lens group having a positive focal length, a second lens group having a negative focal length, a third lens group having a positive focal length, a fourth lens group having a negative focal length which are arranged in order from an object side to an image side, and a diaphragm disposed between the second and third lens groups. During a change of zoom ratio from short to long focus end, the first to fourth lens groups move so that an interval between the first and second lens groups increases, an interval between the second and third lens groups decreases, and an interval between the third and fourth lens groups increases. The first lens group includes first and second negative lenses, a reflective optical element, and at least one positive lens arranged in order from the object side to the image side.

Abstract: A zoom lens, including: a first group optical system having a negative focal length; a second group optical system having a positive focal length; a third group optical system having a positive focal length, the first group optical system, the second group optical system and the third group optical system being arranged in this order from an object side to an image side; and an aperture stop configured to move together with the second group optical system and disposed on the object side of the second group optical system, a change in magnification being carried out by decreasing a space between the first group optical system and the second group optical system when the change in magnification is carried out from a short focal length end to a long focal length end.

Abstract: A zoom lens unit includes, in order from an object side to an image side: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a negative refracting power; a fifth lens group having a positive refracting power; and a sixth lens group having a negative refracting power, an aperture stop is disposed between the second lens group and the third lens group, and when changing magnification from a wide-angle end to a telephoto end, at least the second lens group, the third lens group and the fifth lens group are moved, and the first lens group includes a reflecting optical element which bends a light path in the first lens group to obtain a predetermined light path length.

Abstract: A zoom lens comprises a first lens group G1, which includes a negative focal length, a second lens group G2, which includes a positive focal length, a third lens group G3, which includes a negative focal length, a fourth lens group G4, which includes a positive focal length, and a fifth lens group G5, which includes a positive focal length, in order from nearest to furthest from a photographic subject, or with a sixth lens group G6, which includes a negative focal length, installed as an anchored lens group between the fifth lens group and an image site of the camera apparatus.

Abstract: An image reading apparatus includes: a light source which irradiates illumination light to a document; an imaging element which images reflected light of the illumination light from the document; a color separator which performs color separation of the illumination light or the reflected light into at least three wavelength ranges including a first wavelength range, a second wavelength ranges and a third wavelength range; a light-receiving element which converts the reflected light imaged by the imaging element into an electrical signal as a document image of the document, for each of the at least three wavelength ranges; and an image processor which classifies the document image on the basis of the electrical signal in the first wavelength range and in the second wavelength range.

Abstract: An illumination unit for use in an image read apparatus is provided which illuminates a surface of an original document with illumination light, reads an image of the original document by a light receiving element, and adjusts an amount of specular light reflection from the surface of the original document on a light receiving plane of the light receiving element by adjusting at least one of an incident angle of the illumination light and a divergence thereof. It includes a plurality of light source units emitting the illumination light and arranged in a direction so that a direction in which intensity of light emitted from at least one of the light source units closest to a center of the arrangement thereof is to be highest makes a non-perpendicular angle with the direction of arrangement.

Abstract: A zoom lens including subsequently from an object side of the zoom lens to an image side of the zoom lens: a first lens group with a positive focal length; a second lens group with a negative focal length, an aperture arranged on an object side of a third lens group; the third lens group with a positive focal length, a forth lens group with a positive focal length. By zooming from a short focal end to a long focal end, an interval between the first lens group and the second lens group increases, an interval between the second lens group and the third lens group decreases, an interval between the third lens group and the fourth lens group increases. The first lens group has sequentially from an object side of the first lens group: a negative meniscus lens L1 having a convex surface facing the object; a positive lens L2; satisfying a conditional expression: Nd11>1.96 (Nd11: a refractive index of the negative meniscus lens L1.

Abstract: A zoom lens, including: a first group optical system having a negative focal length; a second group optical system having a positive focal length; a third group optical system having a positive focal length, the first group optical system, the second group optical system and the third group optical system being arranged in this order from an object side to an image side; and an aperture stop configured to move together with the second group optical system and disposed on the object side of the second group optical system, a change in magnification being carried out by decreasing a space between the first group optical system and the second group optical system when the change in magnification is carried out from a short focal length end to a long focal length end.

Abstract: A zoom lens including subsequently from an object side of the zoom lens to an image side of the zoom lens: a first lens group with a positive focal length; a second lens group with a negative focal length, an aperture arranged on an object side of a third lens group; the third lens group with a positive focal length, a forth lens group with a positive focal length. By zooming from a short focal end to a long focal end, an interval between the first lens group and the second lens group increases, an interval between the second lens group and the third lens group decreases, an interval between the third lens group and the fourth lens group increases. The first lens group has sequentially from an object side of the first lens group: a negative meniscus lens L1 having a convex surface facing the object; a positive lens L2; satisfying a conditional expression: Nd11>1.96 (Nd11: a refractive index of the negative meniscus lens L1.